IgA Nephropathy Patients Research Articles

#1643 Long-term cohort study on the prognostic impact of mesangial IgM deposition in IgA nephropathy

Abstract Background and Aims The prognostic importance of mesangial immunoglobulin (Ig) M deposition in IgA nephropathy (IgAN) is not well-understood and is subject to ongoing debate. Moreover, mesangial IgM deposition could also reflect lectin complement system activation. Thus, our study sought to examine the long-term prognostic implications of mesangial IgM deposition in a cohort of IgAN patients. Method We carried out a single-center retrospective study involving 93 consecutive IgAN patients (median age 41 years, 68% male, eGFR 48.7 mL/min, proteinuria 1.1 g/g) from 2010 to 2015. The follow-up period extended until the onset of end-stage kidney disease (ESKD), death, or January 2021, with a median duration of 7 years. An independent pathologist assessed the IgM immunofluorescence pattern, Oxford MEST-C score, and transmission electron microscopy (TEM) lesions using a detailed protocol. Results In our study, 70% (n = 65) of patients exhibited mesangial IgM-positive deposits, while 30% (n = 28) did not show IgM deposition. Both IgM-positive and IgM-negative groups were comparable in terms of age (40 vs 43 years, p 0.6), sex (69 vs 64% male, p 0.6), arterial hypertension prevalence (69 vs 64%, p 0.6), Charlson comorbidity scores (2 vs 1, p 0.3), kidney function (eGFR 46 vs 55 mL/min, p 0.1 and proteinuria 1.2 vs 0.7, p 0.1), pathology findings (including Oxford MEST-C score, IgG and C3 immune deposition), TEM analysis, as well as in their treatment with renin-angiotensin-system inhibitors (63 vs 71%, p 0.4) and immunosuppression (39 vs 39%, p 0.9), and mortality rates (11 vs 7%, p 0.5). However, a notable difference emerged in the progression to ESKD, with 37% of IgM-positive patients advancing to this stage compared to only 11% of those in the IgM-negative group (p 0.01). The multivariate Cox proportional hazards regression analysis identified lower eGFR (HR 0.94, 95% CI: 0.92, 0.97), higher Oxford MEST-C score (HR 1.53, 95% CI: 1.16, 2.02), and mesangial IgM deposits (HR 4.75, 95% CI: 1.25, 17.99) as independent predictors of reduced kidney survival. Conclusion Our study identifies mesangial IgM deposition as a potential risk factor for ESKD in advanced IgAN, suggesting a need for further investigation. Future research should explore whether IgM's activation of the lectin complement pathway and resultant damage, as proven in ischemia-reperfusion injury models, are applicable to IgAN.

#2922 The role of urinary extracellular-derived miRNAs dysregulation in IgA nephropathy

Abstract Background and Aims IgA nephropathy (IgAN) is one of the most common forms of glomerulonephritis and causes hematuria and proteinuria by damaging the mesangial and podocyte cells. Urinary extracellular vesicles (uEVs) derived from damaged podocytes may reflect podocyte damage in various glomerular diseases and are considered an early and noninvasive diagnostic method. This study aimed to extract urinary extracellular vesicles (EVs) and investigate the expression dysregulation and diagnostic value of miR-29c, miR-146a, miR-148b, miR-155, miR-200b, and miR-429 in urine samples from patients with IgAN. Method Urine samples were collected from 20 patients with IgAN, 30 patients with membranous nephropathy (MGN), and 16 healthy individuals to extract Urinary EVs by ultracentrifugation. The characterization of EVs was evaluated by the specific protein markers of the EVs, flotillin-1, ALiX, and CD-9, along with histone H1 and podocyte-specific marker podocalyxin via western blotting. SEM and DLS were used to investigate the size and morphology of EVs. The expression levels of the miRNAs were evaluated using Real-time PCR. Results Numerous extracellular vesicles >100 nm in size were present in the urine sample which were considered as EVs based on references. There were higher levels of the specific markers flotillin-1, ALiX, and podococalyxin in the urine samples of IgAN patients than in the control samples (P < 0.001 and P < 0.001, respectively). There was a statistically significant difference among the expression level of miR-29c (P = 0.002 and P = 033) in the group of IgAN patients compared to MGN patients and the group of healthy people, based on Rock curve analysis this urinary marker could discriminate the IgAN patients from MGN group, the area under the curve AUC ≥ 0.73. Conclusion This study showed that the different levels of miRNAs studied in urinary EVs may indicate podocyte damage and have a direct relationship with the pathology of IgAN and MGN. Further studies are needed to confirm these results and determine the diagnostic value of these markers.

#2809 Peroxiredoxins, the potential predictor of eGFR decline in patients with IgA nephropathy

Abstract Background and Aims Multiple factors may contribute to development and progression of glomerulopathies (GN), one of them is oxidative stress (OS). 2-cysteine-peroxiredoxins (PRDXs) possess the ability to reduce excessive levels of OS mediators and are crucial for cellular OS regulation. In our pilot study, we found that PRDXs 1-5 are differentially changed in patients with IgA nephropathy (IgAN), lupus nephritis (LN) and membranous nephropathy (MN). Thus, the aim of the current study was to evaluate if PRDXs 1-5 may be a prognostic marker for these 3 types of GN. Method We followed-up (5-year observation) 80 previously recruited patients with: IgAN (n = 36); MN (n = 23) and LN (n = 21). Patients were classified, based on the eGFR change (decline vs. stable and/or increase) and baseline PRDXs 1-5 levels (Table 1). The Mann Whitney-U, Kruskal-Wallis Test and Pearsons’ correlation were used for statistical analysis, the p-values <0.05 were considered significant. Results Baseline measurements indicated that the mean serum PRDXs 1-5 concentrations differ between the GN types. During the follow-up, we observed the significant association of eGFR decline with low baseline PRDX-2 level (p = 0.049) in patients with IgAN (Fig. 1). Conclusion We suggest the possible link between peroxiredoxins and deterioration of kidney function, particularly in IgAN patients.

#2365 Spectrum and prevalence of renal pathologies: a retrospective analysis of biopsy data from a tertiary care center in India

Abstract Background and Aims Renal biopsy remains a cornerstone in diagnosing various nephropathies, providing vital insights into disease etiology and guiding therapeutic strategies. In India, where the burden of renal diseases is on the rise, characterizing the spectrum of renal pathologies through biopsy can significantly influence clinical outcomes. Despite increasing global data on kidney diseases, regional variations exist, and localized data from tertiary care centers in India are sparse. The primary objective of this study was to delineate the spectrum of renal diseases diagnosed via biopsy at a tertiary care center in New Delhi, India, over a seven-year period. Method This retrospective study analyzed records from a tertiary care center in New Delhi, India, from 2015 to 2022. Data were extracted from paper-based records and electronic medical records (EMR). The study included patients who underwent native kidney biopsy during this period. Graft biopsies and biopsies with inadequate samples were excluded. Biopsies were evaluated by nephropathologists, and diagnoses were categorized based on standardized criteria. Results Between 2015 and 2022, 1,174 renal biopsies were analyzed from patients aged 1.3 to 82 years, with an average age of 40.5 years, showing a male predominance (60%). Chronic Interstitial Nephritis was the most prevalent diagnosis at 14.58%, followed by Diffuse Global Glomerulosclerosis at 13.13%, and IgA Nephropathy at 12.77% (Table 1). In IgA Nephropathy patients (n = 141), the majority exhibited microhematuria (53.9%) and subnephrotic proteinuria (56.02%), while 24.82% presented with nephrotic range proteinuria. Lupus Nephritis was the most common secondary glomerular disease (6.34%). Within the Lupus Nephritis subgroup (n = 70), Class IV (34.29%) and Class V (24.28%) were the most observed classes, with a notable presence of combined Class III+V (10%) and Class IV+V (8.57%). Within the cohort, the most common primary glomerulonephritis diagnosed in the age group of 18-30 years was IgA Nephropathy. For the 30-60 years demographic, Membranous nephropathy was most frequently identified, while in those older than 60 years, Diabetic Glomerulosclerosis was predominant. In cases presenting with hematuria (n = 417), IgA Nephropathy was identified in 17.74%. Among those with rapidly progressive renal failure (n = 79), Pauci immune GN accounted for 46.83% of diagnoses, followed by IgA Nephropathy at 15.18%. For patients with nephrotic range proteinuria (n = 139), IgA Nephropathy, Membranous nephropathy, and FSGS were leading diagnoses, each accounting for 12.94%, 12.23%, and 12.23% respectively. Conclusion The analysis revealed IgA Nephropathy as the most common histopathological finding in renal biopsies. The primary indication for biopsy is nephrotic range proteinuria. In this category, IgA Nephropathy is also the most prevalent diagnosis. For patients with rapidly progressive renal failure, Pauci immune GN is the most frequent finding. Additionally, IgA Nephropathy is the leading cause in patients presenting with hematuria. Lupus Nephritis is the most common secondary glomerular disease with class IV being the most common biopsy finding. The study underscores the necessity for continued surveillance of renal pathology trends to inform healthcare strategies in India.

#1522 Comparative analysis of clinical and pathological traits in IgA nephropathy with nephrotic range proteinuria based on serum albumin level

Abstract Background and Aims Presently, the clinical outcomes associated with IgA nephropathy exhibiting heavy proteinuria and the potential correlation between decreasing serum albumin levels and adverse prognosis have not been conclusively established. The present study was designed to elucidate the clinical and pathological characteristics of IgA nephropathy patients who present with nephrotic-range proteinuria, particularly in relation to serum albumin levels. Method This retrospective cohort study was conducted using data from biopsy-confirmed IgA nephropathy patients presenting with nephrotic-range proteinuria between 2017 and 2022 from eight university-affiliated hospitals in South Korea. Patients were stratified into two groups based on a serum albumin level of 3.0 g/dl. The study involved a comparative assessment of clinical and pathological characteristics across these two groups, as well as an evaluation of clinical prognosis with respect to the end-stage kidney disease (ESKD). Results The analysis included a total of 127 patients. Of these, 86 patients had a serum albumin level above 3.0 g/dl (designated as the preserved albumin group, or PA group), while 41 patients had levels below 3.0 g/dl (designated as the reduced albumin group, or RA group). The baseline characteristics of the two groups were found to be statistically similar. The mean age of the patients was 46.46 years, and 46.46% were male. In the laboratory findings, the RA group had significantly elevated erythrocyte sedimentation rate compared to the PA group. Additionally, total cholesterol and low-density lipoprotein-cholesterol levels were significantly higher in the RA group compared to the PA group. Proteinuria was observed to be significantly higher in the RA group. Pathological examinations demonstrated that in electron microscopy (EM) findings, the RA group exhibited a more pronounced diffuse foot process effacement. Over the course of one year, the trend in creatinine changes exhibited differences between the two groups over time (time x group interaction P = 0.002). Furthermore, it appeared that the reduction in the quantity of proteinuria was more substantial within the RA group (time x group interaction P = 0.001). During a median follow-up period of 25.22 months (ranging from 11.98 to 49.23 months), 14 patients (11.02%) in the PA group progressed to ESKD, compared with 10 patient (24.39 %) in the RA group. However, there was no statistically significant difference between the two groups in terms of progression to ESKD (P = 0.330). Conclusion In patients diagnosed with IgA nephropathy presenting with nephrotic-range proteinuria, a decline in serum albumin levels was associated with diffuse foot process effacement, and the decrease in serum albumin was not found to be associated with adverse prognosis.

#322 Are platelet-related parameters prognostic predictors of renal and cardiovascular outcomes in IgA nephropathy?

Abstract Background and Aims IgA nephropathy (IgAN) is associated with chronic inflammation. Platelet-related parameters, such as platelet (PLT) count, platelet-to-albumin ratio (PAR) and platelet-to-lymphocyte ratio (PLR), were examined as potential prognostic indicators for renal and cardiovascular (CV) outcomes in IgAN. Method 150 IgAN patients were involved and divided into two groups based on the cut-off value of PAR. All-cause mortality, major CV events and end-stage renal disease were the primary combined endpoints. Secondary endpoints, such as CV or renal endpoints, were also analyzed separately. Results Seventy-four per cent of patients were male and had a mean age of 43.7 ± 13.5 years. Mean follow-up time: 124 ± 67 months. The K-M curve showed that PLT, PLR and PAR were strongly associated with primary combined and renal outcomes, but not with cardiovascular outcomes in IgAN. In the case of combining PAR with LVH, the K-M curves showed significant differences in both the primary (p < 0.001) and secondary outcomes (p = 0.001 and p = 0.038). When we combined PAR with metabolic syndrome, the primary (p < 0.001) and secondary (p = 0.001 and p = 0.015) outcomes were also significant in the low and high PAR groups. PAR was correlated with gender (r = -0.273, p = 0.001) and segmental glomerulosclerosis on histology (r = 0.161, p = 0.047). PLR correlated with microalbuminuria (r = -0.165, p = 0.033) and left ventricular hypertrophy (r = -0.178, p = 0.025). PLT was correlated with gender (r = -0.201, p = 0.013) and eGFR (r = 0.158, p = 0.040). PLR, gender, dyslipidemia and microalbuminuria were associated with the primary composite endpoints; left ventricular hypertrophy and microalbuminuria with the secondary renal endpoints; and gender, age and diabetes with the cardiovascular endpoints by multivariate Cox regression. Conclusion Elevated PAR and PLR may predict end-stage renal disease progression, but in combination with LVH and MetS, they showed CV events also in IgAN. The determination of PAR and PLR can be useful and cost-effective parameters for assessing both cardiovascular and renal risks in CKD.

#1170 Efficacy and safety of telitacicept in IgA nephropathy: a real-world study

Abstract Background and Aims IgA nephropathy (IgAN) is the most common primary glomerular disease in the world, and the specific therapeutic methods are limited in IgAN. Telitacicept is a humanized fusion protein composed of a transmembrane activator and calcium-modulating cyclophilin ligand interactor receptor and human IgG. This study was designed to evaluate the efficacy and safety of telitacicept in adult patients with IgAN in a real-world study. Method Biopsy-proven IgAN patients with 24-hour proteinuria greater than 0.5 g/day who received telitacicept 240 mg once a week were recruited in this study and 1:1 matched with patients who received supportive treatment only or immunosuppressive treatment by propensity score matching. The primary outcome was the change from baseline in 24-hour proteinuria over the 3-month follow-up. Results Twenty-one patients in each group were enrolled. The mean eGFR was 80.1 ml/min/1.73 m2, and the median 24-hour urine protein level was 1.48 g/day. At the end of the 3-month follow-up period, telitacicept reduced median proteinuria by 0.72 g/d (54.6%) from baseline, compared with a reduction of 0.18 g/d (20%) in the supportive treatment group (P < 0.001), and 1.12 g/d (72.1%) in the immunosuppressive treatment group (P = 0.814). Preserved eGFR levels were observed in the telitacicept group (1.9 ml/min/1.73 m2 [4.3%]), while the eGFR level declined in the supportive treatment group (- 2.9 ml/min/1.73 m2 [- 5.8%]) and immunosuppression group (- 6.1 ml/min/1.73 m2 [- 8.4%]). No serious adverse events were observed in the telitacicept treatment group. Injection site reactions were more prevalent in the telitacicept group (8/21 [38.1%]), meanwhile immunosuppression group had more respiratory tract infections (7/21, [33.3%]). Conclusion Telitacicept can reduce proteinuria in patients with IgAN and showed a favourable safety profile in patients with IgAN.

#1638 Long-term mortality trends in IgA nephropathy: a study of an Eastern European cohort

Abstract Background and Aims IgA Nephropathy (IgAN), recognized as the most prevalent form of primary glomerulonephritis, has been thoroughly researched in terms of renal outcomes. However, there is a scarcity of data regarding patient survival, especially in Eastern Europe. Our study focuses on exploring the long-term survival rates of IgAN patients and identifying associated risk factors within an Eastern European population. Method In our retrospective study, we analyzed 215 patients with biopsy proven IgAN (median age 44 years, 71% male, median eGFR 40.9 mL/min/1.73 m2, median proteinuria 1.24g/g) diagnosed at a tertiary center in Romania from 2010 to 2017. Our study primarily focused on all-cause mortality and secondarily on the development of ESKD (start of kidney replacement therapy or renal transplantation). The follow-up for patients continued until they reached either of these endpoints or until January 1, 2022, whichever came first. Results During a median follow-up of 7.3 years, 20% of the patients died. The main causes of death were cardiovascular diseases (60%), followed by infectious (19%), gastroenterological (12%), and neoplasia (9%) diseases. Mean survival of the entire cohort was 117.5 months (95% CI: 111.2, 123.8) and mean kidney survival was 98.4 months (95% CI: 90.5, 106.2). Survival rates at 1 year, 5 years and 10 years were 93%, 84% and 77% respectively, and kidney survival rates at 1 year, 5 years and 10 years were 87%, 72% and 58% respectively. When compared to the survivors, deceased patients were significantly older (60 vs 42 years, p 0.001) and had an increased prevalence of diabetes mellitus (26 vs 4%, p 0.001) and higher Charlson comorbidity index (5 vs 2, p 0.001). Deceased patients also had significantly higher serum creatinine levels (3.3 vs 1.6 mg/dL, p 0.001), lower eGFR (18 vs 46 mL/min, p 0.001), and more haematuria (230 vs 183cells/HPF, p 0.01). There was no significant difference in proteinuria between the two groups (1.1 vs 1.2g/g, p 0.3). In the univariate Cox regression analysis, all-cause mortality was significantly associated with several factors: advancing age (HR 1.08, 95% CI: 1.05, 1.11), an increased Charlson comorbidity index (HR 1.60, 95% CI: 1.42, 1.80), the presence of diabetes mellitus (HR 5.13, 95% CI: 2.57, 10.25), lower eGFR (HR 0.95, 95% CI: 0.93, 0.97), increased proteinuria (HR 1.12, 95% CI: 1.00, 1.25), the presence of haematuria (HR 1.26, 95% CI: 1.03, 1.53), lower serum albumin (HR 0.35, 95% CI: 0.22, 0.56), higher MEST-C score (HR 1.38, 95% CI 1.13, 1.69) and absence of renin-angiotensin-system inhibitors (RASI) (HR 0.32, 95% CI 0.17, 0.60). However, in the multivariate analysis, only an increased Charlson comorbidity index (HR 1.31, 95% CI: 1.09, 1.57), lower eGFR (HR 0.98, 95% CI: 0.96-1.00) and absence of RASI (HR 0.21, 95% CI: 0.15, 0.28) retained their statistical significance. Conclusion We report a 20% mortality rate in our Eastern European IgAN cohort, primarily due to cardio-vascular diseases. Death correlates with increased age, comorbidity burden, decreased renal function at diagnosis, and absence of RASI use. RASI treatment may potentially improve survival, highlighting its importance in managing IgAN.

#1039 Characteristics and outcome of IgA nephropathy in Switzerland – a single center perspective

Abstract Background and Aims IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide leading to end-stage kidney disease (ESKD) in roughly 40% of affected patients by ten years. Geographic differences in clinical course and response to treatment may partly result from different disease entities. The purpose of this retrospective cohort analysis was to study all cases of IgAN from a single tertiary center with respect to clinical and histological characteristics, treatment practices and outcome. Method This retrospective cohort analysis identified 158 cases of adult biopsy-proven IgAN by chart review diagnosed between 1980 and 2017. Detailed phenotypisation including clinical, paraclinical, histological, treatment and outcome parameters was performed. Remission status was defined as described previously (Reich 2007). Statistical analysis was performed using Excel and SPSS software and included standard descriptive methods and included standard descriptive methods and student's t-test on a significance level of 0.05. Results Subjects were majorly male and of Caucasian descent. Mean estimated glomerular filtration rate (eGFR) according to Chronic Kidney Disease Epidemiology Collaboration formula at diagnosis was 55.3 ml/min/1.73 m2, mean proteinuria was 3.2 g/d. 70.3% of patients were hypertensive at presentation. Clinical presentation varied according to age. Thus, younger patients (18-39 years) presented more frequently with macrohematuria, asymptomatic urine abnormalities and by trend acute kidney injury whereas nephrotic syndrome and extrarenal symptoms were recorded in similar proportions of patients (Fig. 1). 28.5% of initial biopsies showed moderate to severe tubular atrophy and interstitial fibrosis (IFTA), 38% included crescents, 1.9% > 50% crescents. 86.1% of the patients were treated by renin-angiotensin-aldosterone-system inhibitors, 46.8% received immunosuppressive therapy including steroids in 46.2% and other immunosuppressive medications in 19.6% the most common being azathioprine (Fig. 2). There were 33.5% complete and 13.3% partial remissions. Progression to ESKD was noted in 42.1%. 51.4% of patients treated with immunosuppressive therapy experienced remission. Recurrence rate after transplantation was 18.4%. Patients treated by immunosuppressants had higher levels of baseline proteinuria (3.2 ± 2.3 vs. 1.6 ± 1.6 g/d, p < 0.00001), lower baseline eGFR (50 ± 31 vs. 61 ± 30 ml/min/1.73 m2, p = 0.04), higher number of crescents (9.4 ± 15.0 vs 2.3 ± 8.5%, p = 0.001), higher IFTA scores (1.7 ± 0.8 vs. 1.3 ± 0.6, p = 0.007) and higher fluorescence intensity scores for C3 (2.0 ± 0.9 vs. 1.6 ± 0.9, p = 0.02) on initial biopsy as compared to patients treated conservatively. Patients progressing to ESKD presented with higher blood pressure (146 ± 26 vs. 135 ± 18 mmHg systolic, p = 0.005; 89 ± 14 vs. 82 ± 14 mmHg diastolic, p = 0.006), lower eGFR (41 ± 29 vs. 64 ± 28 ml/min/1.73 m2, p = 0.00001), higher levels of proteinuria (3.4 ± 2.0 vs. 1.8 ± 1.9 g/d, p = 0.0001), higher number of crescents (9 ± 17 vs. 4 ± 9%, p = 0.03) and higher IFTA scores (1.8 ± 0.8 vs. 1.3 ± 0.6, p = 0.00001) as compared to patients without ESKD at last follow up. Baseline blood pressure (134 ± 18 vs. 147 ± 26 mmHg systolic, p = 0.004; 82 ± 14 vs. 89 ± 15 mmHg diastolic, p = 0.01), eGFR (60 ± 29 vs. 41 ± 27 mmHg, p = 0.0007), proteinuria (2.3 ± 1.9 vs. 3.2 ± 2.3 g/d, p = 0.03) and severity of IFTA (1.4 ± 0.6 vs. 1.8 ± 0.9, p = 0.003) differed significantly between patients who experienced any remission vs. those who did not achieve remission respectively. Conclusion This analysis gives insight into the characteristics and treatment practices of a Swiss single center cohort of IgAN patients from 1980-2017.

#1392 MEST-C score correlation with proteinuria reduction after SGLT2i treatment in patients with IgA nephropathy

Abstract Background and Aims Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with better cardiovascular outcomes and with nephroprotection independent of diabetes status. Recent data suggest that SGLT2i significantly reduce proteinuria in patients with IgA nephropathy (IgAN). Data available for the use of the MEST-C score to determine if treatment would benefit IgAN patients is scarce. The aim of our study was to assess the degree of proteinuria reduction after SGLT2i treatment in IgAN and its possible association with the MEST-C score. Method 63 adult patients with biopsy-proven IgA nephropathy, eGFR ≥ 30 mL/min/1.73 m2 (CKD-epi), and total urine protein of >0.5 grams/day at screening were included. Patients with secondary IgAN and crescents were excluded. All receiving maximally tolerated RASi for at least 12 weeks. All patients started dapagliflozin 10 mg once per day after baseline data were registered. The total follow-up was 12 months. The main outcome was the decline in eGFR and the reduction in 24-hour proteinuria from SGLT2i initiation to 1,3, 6, 9, 12 months, end-stage renal disease, or kidney or cardiovascular death. Three repeated measurements of proteinuria (mg/24H) were performed, 90 days before SGLT2i treatment initiation, and only patients with stable proteinuria were enrolled in the study. Results 49 patients (35/14 M/F), with mean age of 41,9 ± 19,6 years, completed follow up. 8 patients discontinued treatment due to adverse events attributed to dapagliflozin. At baseline eGFR was 68.21±18,1 ml/min/1.73 m2 and Upr: 2196±1091 mg/24H. The MEST-C scores were correlated with the serum creatinine level, proteinuria, and hematuria. The mean serum creatinine level was higher in M1, E1, S1, and T1 compared with score “0”. It was statistically significant (p = 0.03) only in the T-score. The mean proteinuria level was again higher in M1, S1, and T1 but reached statistical significance (p = 0.037) in only the T1-score. E1 has higher hematuria. The Upr/24H difference for dapagliflozin was −24.7% (95% CI −27.5, −23.2; p < 0.001) at the end of follow-up (month 12). Proteinuria reduction was similar across all eGFRs, age, and baseline proteinuria. Among MEST-C score parameters, T1 had a negative impact on the antiproteinuric effect of dapagliflozin (p = 0.01) No hypoglycemic events were reported and no deaths occurred. Conclusion In the present study, the use of SGLT2i was associated with a significant reduction of proteinuria in patients with IgA nephropathy and maximally tolerated RASi. We analyzed renal outcomes in association with pathologic features. We established that the presence of the T1 score has a negative impact on proteinuria reduction after SGLT2i treatment. Further studies are needed to investigate the impact of the use of the Oxford Classification score for developing individual treatment therapies.

#425 Felzartamab (anti-CD38) in patients with IgA Nephropathy—interim results from the IGNAZ study

Abstract Background and Aims Most patients with IgA nephropathy (IgAN) will progress to kidney failure within 10-15 years of diagnosis. Sustained proteinuria is the best predictor of adverse long-term kidney outcomes and is a surrogate marker for efficacy. CD38+ plasma cells are likely the main source of pathogenic Gd-IgA1, and the related autoantibodies in IgAN. Felzartamab (felza; HIB202) is a recombinant purified human immunoglobulin G1 (IgG1) monoclonal antibody (mAb) that binds to CD38 on plasma cells and is being studied across immune-mediated kidney diseases such as IgAN, Primary Membranous Nephropathy, Lupus Nephritis, and Antibody Mediated Rejection. The primary aims of the IGNAZ study were to assess: 1) efficacy of felza compared to placebo on urine protein:creatinine ratio (UPCR) and estimated glomerular filtration rate (eGFR) change from baseline, and 2) the relationship between exposure, safety, and efficacy in each of 3 dose groups vs. placebo. Interim results with 15 months of follow-up from this 24-month trial are presented. Method In Part 1, 48 IgAN subjects were randomized in a 1:1:1:1 ratio across a placebo and 3 active arms in this multicenter, double-blind placebo-controlled, phase IIa trial. The M1, M2, and M3 active arms received 2 doses in 15 days, 5 doses in 2 months, and 9 doses in 5 months, respectively. In Part 2, 6 Japanese subjects received the M3 regimen, open-label, and have been followed for 9 months. Key inclusion criteria included ages 18-80 years, biopsy confirmed diagnosis of IgAN within the past 8 years, proteinuria at screening ≥1.0 g/d, eGFR ≥30 ml/min/1.73 m2 (by CKD-EPI), and background stable and maximally tolerated renin angiotensin system inhibitors. Results 48 randomized subjects were enrolled at 28 sites in the US and in 14 different countries in Europe and in Asia, of which 46 completed the treatment phase. Mean (SD) baseline characteristics (Parts 1 and 2 combined): age 41.6 (12.3) yrs, UPCR 1.67 (1.0) g/g, eGFR 74.6 (30.3) ml/min/1.73 m2. 67% of subjects were male. Intention-to-treat with felza demonstrated rapid, clinically meaningful reductions in UPCR with the maximal treatment effect being observed in the M3 9-dose regimen. In Part 1, percentage change from baseline in UPCR was −14% for placebo and −25% for M3 9-dose arm at month 3, and +9% for placebo and −35% for M3 at month 6 (Fig. A). Reductions in proteinuria observed at month 6 persisted until Month 15, 10 months after the last dose: +6% and −38% mean UPCR change from baseline for placebo and the M3 9-dose arm, respectively (Fig. B). Relatively stable eGFR values were observed for the felza arms compared to loss of eGFR in the placebo arm. Rapid, durable reductions in IgA and Gd-IgA1 levels were seen across the dosing arms, with reductions lasting 10 months after the last dose (Fig. C). IgG recovery occurred faster off-treatment than IgA. Results in the Part 2 subjects were similar to the Part 1 M3 cohort through 9 months. There were no apparent dose-dependent adverse events and no exposure-safety relationship. Treatment-emergent adverse events (TEAEs) were generally of mild or moderate intensity or toxicity grade. The most common TEAE assessed as related by study investigator was infusion related reactions (IRR), most of which occurred on the first infusion. There was one treatment-related serious AE due to an IRR. Five subjects discontinued treatment due to IRRs or drug hypersensitivity; for four of the five subjects, the infusion rate was higher than protocol-specified or had an error in pre-medication. TEAE infections were comparable between placebo and felza arms: Placebo (33.3%), M1 (33.3%), M2 (36.4%), M3 (38.5%), Part 2 (50.0%); all were Grades 1 or 2, and non-serious. Conclusion This proof-of-concept study highlights the potential for disease modification in IgAN with the anti-CD38 mAb felza and supports continued research as a potential treatment for high-risk IgAN patients. Felza treatment resulted in clinically meaningful, prolonged UPCR reductions and eGFR stabilization sustained ≥10 months after dosing was completed. Felza was generally well tolerated with rapid recovery of IgG with durable reductions in IgA and pathogenic Gd-IgA1 levels.

#2663 Assessment of in situ alternative and classical convertases as indicators of ongoing glomerular complement activation in IgA nephropathy

Abstract Background and Aims Complement activation is involved in IgA nephropathy (IgAN), opening up new avenues for complement-targeting therapies. However, precise patient selection and optimal timing for these therapies are essential. Current diagnostic methods of complement activation in IgAN, based on immunostaining, lack precision in identifying specific pathway(s) involved and distinguishing ongoing from past complement activation. Method Complement deposition analysis was conducted on kidney biopsy samples from 53 patients with primary IgAN at diagnosis (NCT05234463). Glomerular complement deposition was assessed through immunohistochemistry for C4d and C5b-9 and immunofluorescence for C3b/iC3b and C1q. In situ detection of C3/C5 convertases complexes from complement classical/lectin (C4b2b) and alternative pathways (C3bBb) was performed on paraffin-embedded kidney biopsies from 33 patients using a proximity ligation assay (Duolink®, Sigma). Kidney biopsies from patients with lupus nephritis (LN) and C3 glomerulopathy (C3G) were used as positive controls for classical/lectin and alternative convertases staining, respectively. The signals corresponding to the convertases were quantified using QuPath® Software and correlated with clinical parameters, MEST-C score and C5b-9 staining. Results At diagnosis, all 53 IgAN patients (100%) exhibited C3 mesangial deposition. Additionally, 51.2% were positive for C4d, 16.5% had C1q deposition and 62.7% had C5b-9 deposition. In situ analysis of C3/C5 convertases revealed the presence of glomerular C3bBb convertases in 20/33 (60.6%) patients, with a median positive area of 14.9 [2.5-26.5]%o of glomerular surface. C4b2b convertases were detected in 21/33 patients (63.6%), with a median glomerular positive area of 8.1 [3.4-12.1]%o. Both C3bBb and C4b2b convertases were detected in 13/33 (39.4%) patients (Fig. 1). By contrast, no convertases were detected in 5/33 (15.2%) patients despite positive C3b/iC3b deposition. The intensity of C3bBb staining positively correlated with terminal pathway C5b-9 glomerular deposits (p = 0.0011, r2 0.29). Patients with MEST-C score S1 lesions and/or interstitial fibrosis/tubular atrophy (T1-2) exhibited a more pronounced intensity of C3bBb at diagnosis (p = 0.0093). Conclusion Our study, for the first time, presents evidence of ongoing complement activation at the tissue level in IgA nephropathy (IgAN), showing variable intensities among patients. The visualization of in situ C3/C5 convertases could enhance the functional aspect of pathological examination, helping identify patients with ongoing complement activation, making them potential candidates for complement inhibitors. Further research is necessary to investigate the kinetics of this staining over the natural course of IgAN and its implications for IgAN progression.

#1365 Clinical efficacy of tonsillectomy combined with steroid pulse therapy in IgA nephropathy

Abstract Background and Aims IgA nephropathy is the most common primary glomerulonephritis in the Asia–Pacific region, including Japan, and often leads to dialysis initiation. The etiology of IgA nephropathy remains unclear; however, focal infections such as chronic tonsillitis are proposed. Although tonsillectomy should not be performed for Caucasian IgA nephropathy patients, some Japanese studies reported that the combination of steroid pulse therapy with tonsillectomy (TSP) was more effective than steroid pulse therapy alone for the remission of urinary findings. However, the immunosuppressive treatment regimens vary among studies, and treatment effect of combination therapy in preventing renal functional decline is unclear. This study aimed to compare the efficacy of steroid pulse therapy alone versus TSP in improving the remission rate of urinary findings and preventing renal functional decline. Method This retrospective observational study included 116 patients diagnosed with IgA nephropathy based on renal biopsy and treated between January 1, 2010 and December 31, 2020 in Gifu University Hospital. TSP group underwent tonsillectomy received 0.5 g/day of methylprednisolone intravenously for 3 consecutive days at 1-3 weeks. TSP and steroid pulse therapy alone group had 83 and 33 patients, respectively. Of these, 25 patients per group were matched using propensity score matching based on clinicopathologic factors including age, urinary protein level, estimated glomerular filtration rate (eGFR), and the risk classification for progression to end-stage renal disease. The remission rate of urinary findings and the change in eGFR one year after treatment initiation were compared between the two groups. Remission of urinary findings was defined as a urinary protein level of <150 mg/day and <5 erythrocytes/high-power field in the urine sediment. Results The TSP and steroid pulse therapy alone groups did not significantly differ in baseline characteristics including median age (interquartile range) (58 [47–63] and 56 [49–68] years, respectively), female sex (9 and 7, respectively), mean eGFR (60 ± 20 and 63 ± 21 mL/min/1.73 m2, respectively), median urinary protein level (764 [440–1,472] and 990 [425–1,872] mg/day, respectively) (p > 0.05 for all). The remission rate of urinary findings was significantly higher in the TSP group than in the steroid pulse therapy alone group (72% vs. 20%; p < 0.001, χ2 test). Albeit statistically nonsignificant, the decline in eGFR was smaller in the TSP group than that in the steroid pulse therapy alone group (−1.5 ± 8.1 vs −3.7 ± 10.5 mL/min/1.73 m2, p = 0.416; t test). No severe side effect was observed in both treatment groups. Conclusion The higher remission rate of urinary findings observed in the TSP group compared to the steroid pulse alone group suggested that the addition of tonsillectomy to steroid pulse therapy was a clinically effective treatment for IgA nephropathy. Albeit not significant, the TSP group tended to have a smaller decline in eGFR reduction at one-year follow-up, indicating the need for further studies with long-term observation.

#2161 Phosphodiesterase V inhibitor attenuates the fibrotic gene expression of human renal fibroblast derived from IgA nephropathy: an in-vitro study

Abstract Background and Aims Renal fibrosis (RF) is the final common pathway that determines the progression of many glomerular disease including IgA nephropathy (IgAN). Till date there is no definite therapy available to retard RF. Being the key mediator of fibrosis, TGF-β is being targeted in many studies. Phosphodiesterase V inhibitor (PDE5i) is known to inhibit TGF-β but its role in RF is yet to be established. Hence, in the current in-vitro study we wish to establish the role of PDE5 inhibitor as an inhibitor of TGF-β and hence the RF. Method This is a pilot study to evaluate the efficacy of ‘Phosphodiesterase V inhibitor’ on TGFβ1 induced fibrosis on fibroblasts derived from biopsy specimen of IgA nephropathy patients. Renal fibroblasts were cultured from six IgA patients. The fibroblasts cells were treated with PDE5i inhibitor (tadalafil) (at different doses of 1 µm, 5 µm, 10 µm and 15 µm), both before and after stimulation with transforming growth factor beta-1 (TGF-b1) (at doses of 5 ng/ml, 10 ng/ml, 15 ng/ml and 20 ng/ml). Gene expression was studied by real-time polymerase chain reaction (RT-PCR) for messenger ribonucleic acid (mRNA) of pro-fibrotic genes Col1a1, Col1a2, FN1, CTGF, ASMA, TIMP1, and anti-fibrotic MMP2. Objectives Results Our results shows that TGFβ significantly increased the expression of profibrotic gene (Col1a1, Col1a2, ASMA, CTGF, FN and TIMP1) at concentration of 10 ng/ml in the fibroblast cells derived from IgAN patients. Treatment of fibroblast cells with Tadalafil (PDE5 inhibitor) significantly decreased the pro-fibrotic gene mRNA expression (Col1a1, Col1a2, ASMA, CTGF, FN and TIMP1) with increased anti-fibrotic gene expression (MMP2) at the dose of 5 µm and 10 µm concentration in the fibroblast cells (Fig. 1). Conclusion This study may provide potential therapeutic target for prevention of renal fibrosis in IgAN patients. Till date PDE5 inhibitors were not used for IgAN. We found that, PDE5 inhibitor reduces the fibrosis in this in vitro study, this drug may be proposed as a potential therapy for IgAN.

#2631 Efficacy and safety of Telitacicept combined with low-dose mycophenolate mofetil in IgA nephropathy

Abstract Background and Aims Currently, there is no specific agent blocking for IgA nephropathy. The KDIGO guideline recommends basic treatment with renin-angiotensin-aldosterone system (RAAS) antagonists. MMF can be used for Chinese patients. Telitacicept is a fusion protein composed of transmembrane activator and calcium modulating cyclophilin ligand interactor and fragment crystallizable portion of immunoglobulin G (IgG), which neutralizes the B lymphocyte stimulator and a proliferation-inducing ligand. Telitacicept (240 mg qw ih) treatment led to a clinically meaningful reduction in proteinuria in patients with IgAN in the present phase 2 clinical trial. This study intends to observe the efficacy of Telitacicept (160 mg qw ih) combined with low-dose MMF in the treatment of IgA nephropathy. Method Retrospective analysis involving all biopsy proven IgA nephropathy patients with complete clinical data in our department. After RAAS inhibitor treatment for 3 months, the patient's urinary protein more than 0.75 g/24 h, he or she was given Telitacicept (160 mg qw) combined with Mycophenolate mofetil (1 g, twice a day) was treated for 6 months, and follow-up for 6-12 months. The quantification of 24-hour urinary protein and immunity functional, renal function was observed. Results 25 patients with IgA nephropathy confirmed by renal biopsy were enrolled, 14 males and 11 females, aged 34.32 ± 9.68 years’ old, 3 patients with Lee's grade II, Grade III 17 patients, Grade IV 3 patients, and Grade V 2 patients. For Oxford classification, there were 3 cases with M0, 22 cases with M1 lesions, 20 cases with E0, 5 cases with E1 lesions, 1 case with S0, 24 cases with S1 lesions, 10 cases with T0, 15 cases with T1 lesions, and 17 cases with C0, 8 cases with C1 lesions. The patient's urine protein quantification was 2.52 ± 1.82 g before treatment, after Telitacicept and MMF treatment for 2 months, the proteinuria was 1.05 ± 0.55 g (compared with that before treatment, P = 0.0004), and at 4 months, it was 0.71 ± 0.39 g (compared with that before treatment, P < 0.0001), 0.53 ± 0.31 g at 6 months (compared with than before treatment, P < 0.0001). And the 24-hour urine protein quantification of 13 patients was all lower than 0.5 g/24 hours. The renal function of all patients was stable during the observation period. The serum creatinine before treatment was 83.16 ± 21.85 μmol/L and it was 81.88 ± 19.48 μmol/L (P = 0.83) after 6 months. There were no patients with worsening renal function after treatment. Among them, the renal function of 3 patients was better than that after treatment. During follow-up period for 6- to 12-month, the patient did not develop any pulmonary infection requiring for hospitalization or other infections. Some patients experienced adverse reactions such as pain at the site of injection, but no patient discontinued treatment due to adverse reactions. Conclusion Telitacicept combined with low-dose mycophenolate mofetil is a alternative method for the treatment of IgA nephropathy. It is more effective than mycophenolate mofetil or Telitacicept use alone, and with fewer adverse reactions, especially with S or C lesions of Oxford classification. This is an observational retrospective study with a few cases, it's worthy further randomized clinical study to prove.

The predictive value of free thyroxine combined with tubular atrophy/interstitial fibrosis for poor prognosis in patients with IgA nephropathy.

IgA nephropathy (IgAN), the most common type of glomerulonephritis, has great individual differences in prognosis. Many studies showed the relationship between thyroid hormones and chronic kidney disease. However, the relationship between free thyroxine (FT4), as a thyroid hormone, and IgAN is still unclear. This study aimed to evaluate the impact of FT4 on IgAN prognosis. This retrospective study involved 223 patients with biopsy-proven IgAN. The renal composite outcomes were defined as: (1) ESRD, defined as eGFR < 15 ml/(min·1.73 m2) or initiation of renal replacement therapy (hemodialysis, peritoneal dialysis, renal transplantation); (2) serum creatinine doubled from baseline; (3) eGFR decreased by more than 50% from baseline. The predictive value was determined by the area under the curve (AUC). Kaplan-Meier and Cox proportional hazards analyses assessed renal progression and prognosis. After 38 (26-54) months of follow-up, 23 patients (10.3%) experienced renal composite outcomes. Kaplan-Meier survival curve analysis showed that the renal survival rate of the IgAN patients with FT4<15.18pmol/L was lower than that with FT4≥15.18pmol/L (P < 0. 001). Multivariate Cox regression model analysis showed that FT4 was a protective factor for poor prognosis of IgAN patients, whether as a continuous variable or a categorical variable (HR 0.68, 95%CI 0.51-0.90, P =0.007; HR 0.04, 95%CI 0.01-0.20, P <0.001). ROC curve analysis showed that FT4 combined with t score had a high predictive value for poor prognosis of IgAN patients (AUC=0.881, P<0.001). FT4 was a protective factor for IgAN. In addition, FT4 combined with tubular atrophy/interstitial fibrosis had a high predictive value for poor prognosis of IgAN.

Immunosuppressant Agents as Add-On Therapy Failed to Improve the Outcome of Immunoglobulin A Nephropathy with Crescent Score C1

Introduction: The renoprotective benefits of adding immunosuppressant therapy to corticosteroid (CS) treatment for immunoglobulin A nephropathy (IgAN) patients with less than 25% crescent formation (C1) remain uncertain, warranting further research. Methods: A retrospective study was conducted on IgAN patients with crescent C1 lesions confirmed by renal biopsy at Xinqiao Hospital between May 1, 2017, and May 1, 2020. Patients were stratified into either the CS treatment group or the CS combined with an additional immunosuppressant therapy group. Follow-up assessments were conducted within 24 months. Propensity score analysis was used to match patients receiving CS and CS + immunosuppressant drug treatment in a 1:1 ratio. Primary outcomes included changes in estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR). Subgroup analyses were performed to evaluate the benefits of different populations. Composite endpoint outcomes comprised a 30% eGFR decrease, end-stage kidney disease (ESKD) necessitating dialysis or transplant, or kidney disease-related mortality. Adverse events were also compared between the two groups. Results: 296 IgAN patients with C1 lesions were included in the analysis. Baseline characteristics indicated that IgAN patients in the CS + immunosuppressant group exhibited poorer renal function and higher UACR levels. Propensity score analysis effectively minimized the influence of baseline clinical characteristics, including age, serum creatinine, initial eGFR, UACR, and 24-h proteinuria. Both treatment groups demonstrated continuous eGFR improvement and significant UACR reduction during follow-up, especially at 6 months. However, no significant differences in eGFR and UACR reduction rates were observed between the two groups throughout the entire follow-up period, both before and after matching. Subgroup analysis revealed improved eGFR in both treatment groups, notably among patients with an initial eGFR below 90 mL/min/1.73 m2. Conversely, IgAN patients with C1 lesions and a cellular crescent ratio exceeding 50% treated with CS and immunosuppressant therapy experienced a significant improvement in renal function and a decline in urinary protein creatinine ratio. Composite endpoint outcomes did not significantly differ between the two groups, while the incidence of adverse events was comparable. Conclusion: Our findings suggest that the addition of immunosuppressant therapy to corticosteroid monotherapy did not confer significant therapeutic advantages in patients with C1 lesions compared to CS monotherapy, although some specific patient populations appeared to derive modest benefits from this combined approach.

Indirect Markers of Intestinal Damage in IgA Nephropathy

Introduction: Presence of subclinical intestinal inflammation has repeatedly been shown in IgA nephropathy (IgAN) and the degree of histological inflammation has correlated with abnormal urinary findings. There is lack of noninvasive biomarkers evaluating the presence of subclinical intestinal damage in IgAN. We conducted this study hypothesizing that selected biomarkers regarded as indirect markers of intestinal damage could be elevated in IgAN. Methods: Eighty-five primary IgAN patients (median age 55 years, 54% men) participated in this single-center study in Tampere, Finland. None had end-stage kidney disease or previously diagnosed enteropathies. Celiac disease was excluded with serum transglutaminase 2 antibody (TG2Ab) and endomysial antibody tests and inflammatory bowel disease with fecal calprotectin. Intestinal damage was evaluated from sera with analyses of intestinal fatty-acid binding protein (I-FABP), soluble cluster of differentiation molecule 14 (sCD14), and lipopolysaccharide binding protein. Fourteen people suffering from dyspepsia and 15 healthy people served as controls. Results: I-FABP levels among IgAN patients were higher than in the healthy controls (median 830 pg/mL vs. 289 pg/mL, p < 0.001). Also, sCD14 was increased in IgAN patients compared to dyspepsia controls. Although TG2Ab levels were within the normal range among IgAN patients, they were higher than in the healthy controls (median 1.3 U/mL vs. 0.6 U/mL, p < 0.001). Conclusions: Elevated serum levels of I-FABP were present in primary IgAN patients without known enteropathies. Serum I-FABP may indicate the presence of subclinical intestinal damage. These findings encourage further investigation into the role of the intestine in the pathophysiology of IgAN.

Molecular characterization of m6A RNA methylation regulators with features of immune dysregulation in IgA nephropathy.

The role of RNA N6-methyladenosine (m6A) modification in immunity is being elucidated. This study aimed to explore the potential association between m6A regulators and the immune microenvironment in IgA nephropathy (IgAN). The expression profiles of 24 m6A regulators in 107 IgAN patients were obtained from the Gene Expression Omnibus (GEO) database. The least absolute shrinkage and selection operator (LASSO) regression and logistic regression analysis were utilized to construct a model for distinguishing IgAN from control samples. Based on the expression levels of m6A regulators, unsupervised clustering was used to identify m6A-induced molecular clusters in IgAN. Gene set enrichment analysis (GSEA) and immunocyte infiltration among different clusters were examined. The gene modules with the highest correlation for each of the three clusters were identified by weighted gene co-expression network analysis (WGCNA). A model containing 10 m6A regulators was developed using LASSO and logistic regression analyses. Three molecular clusters were determined using consensus clustering of 24 m6A regulators. A decrease in the expression level of YTHDF2 in IgAN samples was significantly negatively correlated with an increase in resting natural killer (NK) cell infiltration and was positively correlated with the abundance of M2 macrophage infiltration. The risk scores calculated by the nomogram were significantly higher for cluster-3, and the expression levels of m6A regulators in this cluster were generally low. Immunocyte infiltration and pathway enrichment results for cluster-3 differed significantly from those for the other two clusters. Finally, the expression of YTHDF2 was significantly decreased in IgAN based on immunohistochemical staining. This study demonstrated that m6A methylation regulators play a significant role in the regulation of the immune microenvironment in IgAN. Based on m6A regulator expression patterns, IgAN can be classified into multiple subtypes, which might provide additional insights into novel therapeutic methods for IgAN.

Albuminuria predicts kidney events in IgA nephropathy.

KDIGO recommends proteinuria <1g/d as a treatment target in patients with immunoglobulin A nephropathy (IgAN) because of high-risk of progression to kidney failure. However, long-term kidney outcomes in patients with low-grade proteinuria remain insufficiently studied. We enrolled patients with biopsy-proven primary IgAN from the Swedish Renal Registry and analyzed associations between urine albumin-to-creatinine ratio (uACR, in categories<0.3, ≥0.3-0.5, ≥0.5-1.0, ≥1.0-1.5, ≥1.5-2.0 and≥2.0g/g) and the occurrence of major adverse kidney events (MAKE, a composite of kidney replacement therapy [KRT] and>30% decline in eGFR). We also explored the risk of kidney events associated with change in uACR within a year. We included 1269 IgAN patients (74% men, median 53 years, mean eGFR 33mL/min/1.73m², median uACR 0.7g/g). Over median follow-up of 5.5 [2.8;9.2] years, 667 MAKE and 517 KRT events occurred, and 528 patients experienced>30% eGFR decline. Compared with uACR<0.3g/g, any higher uACR category was strongly and incrementally associated with the risk of MAKE (adjusted HR ranging from 1.56 [95%CI 1.14-2.14] if uACR 0.3-0.5g/g to 4.53 [3.36-6.11] if uACR≥2.0g/g), KRT (HR ranging from 1.39 to 4.65), and eGFR decline>30% (HR ranging from 1.76 to 3.47). In 785 patients who had repeated uACR measurements within a year, and compared with stable uACR, the risk of kidney events was lower if uACR decreased by 2-fold (HR ranging from 0.47 to 0.49), and higher if uACR increased by 2-fold (HR from 1.18 to 2.56), irrespective of baseline uACR. There is substantial risk of adverse kidney outcomes among patients with IgAN and uACR between 0.3 and 1.0g/g, a population currently considered at low-risk of CKD progression. Reduction in uACR is associated with better kidney outcomes, irrespective of baseline uACR.