IgA Nephropathy Patients Research Articles

IgA vasculitis in adults, pediatrics and non-vasculitic IgA nephropathy, retrospective analysis from 2 centers.

Renal involvement represents the major long-term morbidity associated with IgA vasculitis (IgAV). Our aim was to evaluate clinical characteristics and long-term renal outcomes of IgAV in pediatrics and adults comparing to IgA nephropathy (IgAN). Our retrospective study included children and adults with IgAV and IgAN patients, admitted in a 13-year period (2007-2019) to rheumatology clinics and in hospital pediatric and internal medicine departments. We compared frequencies of clinical manifestations, laboratory findings, treatments, long-term outcomes at 1 year follow-up, including all-cause mortality and dialysis until the end of follow-up time. A total of 60 adult IgAV, 60 pediatric IgAV and 45 IgAN patients were evaluated. Adult IgAV patients were significantly older than IgAN patients (53.1 ± 17.4 years vs 45.1 ± 15.7 years respectively, P = .02) and had significantly higher rates of cardiovascular comorbidities. The risk and time to dialysis were similar among IgAN and adult IgAV groups. Yet, overall mortality at long term follow up was higher in IgAV adult group compared to IgAN. No dialysis or renal transplantation were reported in pediatric IgAV patients. IgAV and IgAN adult patients were comparable regarding risk of end stage renal disease. Of note, high mortality rates were observed among adult IgAV group.

Understanding patient needs and predicting outcomes in IgA nephropathy using data analytics and artificial intelligence: a narrative review.

This narrative review explores two case scenarios related to immunoglobulin A nephropathy (IgAN) and the application of predictive monitoring, big data analysis and artificial intelligence (AI) in improving treatment outcomes. The first scenario discusses how online service providers accurately understand consumer preferences and needs through the use of AI-powered big data analysis. The author, a clinical nephrologist, contemplates the potential application of similar methodologies, including AI, in his medical practice to better understand and meet patient needs. The second scenario presents a case study of a 20-year-old man with IgAN. The patient exhibited recurring symptoms, including gross haematuria and tonsillitis, over a 2-year period. Through histological examination and treatment with renin-angiotensin system blockade and corticosteroids, the patient experienced significant improvement in kidney function and reduced proteinuria over 15years of follow-up. The case highlights the importance of individualized treatment strategies and the use of predictive tools, such as AI-based predictive models, in assessing treatment response and predicting long-term outcomes in IgAN patients. The article further discusses the collection and analysis of real-world big data, including electronic health records, for studying disease natural history, predicting treatment responses and identifying prognostic biomarkers. Challenges in integrating data from various sources and issues such as missing data and data processing limitations are also addressed. Mathematical models, including logistic regression and Cox regression analysis, are discussed for predicting clinical outcomes and analysing changes in variables over time. Additionally, the application of machine learning algorithms, including AI techniques, in analysing big data and predicting outcomes in IgAN is explored. In conclusion, the article highlights the potential benefits of leveraging AI-powered big data analysis, predictive monitoring and machine learning algorithms to enhance patient care and improve treatment outcomes in IgAN.

Serum Phosphorus Might Be a Predictor of Kidney Disease Progression in IgA Nephropathy

Introduction: High serum phosphorus level has been reported to be a risk factor for disease progression in patients with chronic kidney disease, whereas, its role in IgA nephropathy (IgAN) still remains uncertain. This study aimed to investigate the association between serum phosphorus and progression of IgAN. Methods: A total of 247 patients diagnosed with IgAN from 2016.11 to 2019.12 at the First Affiliated Hospital of Xi'an Jiaotong University were retrospectively enrolled in this study. The association between serum phosphorus and kidney disease progression events, defined as 30% estimated glomerular filtration rate (eGFR) decline or kidney failure, was evaluated using Cox models. Results: Serum phosphorus was an independent risk factor for poor renal outcome after adjusting for age, gender, urine protein, MAP, eGFR, hemoglobin, Oxford S and T scores (HR, 2.586; 95% CI, 1.238–5.400, p = 0.011). The addition of serum phosphorus to the reference model containing clinical and pathological variables significantly improved the risk prediction of IgAN progression (C statistic, 0.836; 95% CI, 0.783–0.889) as compared with the reference model (C statistic, 0.821; 95% CI, 0.756–0.886). The ability of serum phosphorus level to predict progression was much stronger in IgAN patients without use of immunosuppression (HR 5.173; 95% CI, 1.791–14.944; p = 0.002). Conclusion: Higher serum phosphorus levels were independently associated with kidney disease progression in patients with IgAN, especially in those without immunosuppression. The addition of serum phosphorus to clinical and pathological data at the time of biopsy significantly improved risk prediction of IgAN progression.

Urinary exosomal miRNA signature of IgA nephropathy: a case–control study

IgA nephropathy is the most common primary glomerulonephritis worldwide and can progress to end-stage kidney disease (ESKD). The current “gold standard” for diagnosis is kidney biopsy, which is invasive and associated with morbidity. miRNAs are small, non-coding endogenous RNA that may serve as non-invasive biomarkers, and that are found in urinary exosomes. Thus far, there is a paucity of studies of the miRNA profile for the diagnosis of IgA nephropathy. Hence, we aimed to study the urinary exosomal miRNA signature of Indian patients with IgA nephropathy. Fifty biopsy-proven IgA nephropathy patients, 50 healthy controls and 25 patients with ESKD (IgA nephropathy) were recruited over 2 years (2020–2022). Urinary exosomes were isolated from which miRNA was extracted . Analysis of urinary exosomal miRNA was done using the digital multiplexed nCounter® human v3 miRNA Expression Assay which contains 799 unique miRNA barcodes. Candidate miRNAs were identified using Lasso regression and consensus clustering. The mean age of IgA nephropathy patients was 36.32 ± 3.067 years, mean creatinine was 2.26 ± 0.318 mg/dl and mean proteinuria was 2.69 ± 0.64 g/day. Compared to healthy controls, the majority (N = 150) of miRNAs were significantly downregulated. Five candidate miRNAs (hsa.miR.146b.3p, hsa.miR.599, hsa.miR.4532, hsa.miR.664b.5p and hsa.miR.221.5p) were able to differentiate between IgA nephropathy cases and controls (AUC > 0.90); the presence of all 5 was associated with 100% specificity and sensitivity for diagnosing IgA nephropathy cases. This study of Indian patients identified that there was a significant difference in the urinary exosomal miRNA profile between IgA nephropathy cases and healthy controls, suggesting that miRNAs may be valuable in the non-invasive diagnosis of IgA nephropathy.

Serum human epididymis protein 4 is associated with disease severity in patients with IgA nephropathy

BackgroundHuman epididymis protein 4 (HE4) is a promising tumor biomarker primarily utilized for the detection of ovarian cancer. However, its potential as a novel diagnostic indicator for immunoglobulin A nephropathy (IgAN) remains unknown. The objective of this study was to investigate the feasibility of serum HE4 as a novel biomarker for patients with IgAN. MethodsThis study enrolled a total of 89 hospitalized patients with IgAN at Peking University Shenzhen Hospital between July 2020 and December 2022, along with 60 healthy control subjects matched for sex and age without evidence of comorbidities. Serum HE4 levels were measured using the Abbott Alinity automated immune analyzer, and the correlation between serum HE4 levels and biochemical markers of renal damage as well as clinicopathologic features in IgAN patients were analyzed. ResultsIn this study, serum HE4 levels were significantly elevated in patients with IgAN compared to healthy controls (116.43 ± 103.61 pmol/L vs. 35.57 ± 9.33 pmol/L, p < 0.001). There was a positive correlation between serum HE4 levels and blood urea nitrogen (r = 0.58, p < 0.001), creatinine (r = 0.73, p < 0.001), cystatin C (r = 0.82, p < 0.001), β2-microglobulin (r = 0.77, p < 0.001), α1-microglobulin (r = 0.75, p < 0.001), and glomerulosclerosis ratio (r = 0.56, p < 0.001). Conversely, a negative correlation was observed between serum HE4 levels and hemoglobin (r = -0.42, p < 0.001), albumin (r = -0.44, p < 0.001) and estimated glomerular filtration rate (eGFR) (r = -0.83, p < 0.001). In HE4+ IgAN patients, a higher glomerulosclerosis ratio (p < 0.01) and lower eGFR levels (p < 0.001) were observed compared to HE4- patients. Furthermore, patients with higher pathological classification grade also had higher serum HE4 levels. ConclusionsSerum HE4 levels were significantly associated with both renal function and the pathological classification of patients with IgAN, indicating that HE4 may serve as a promising biomarker for assessing the severity of IgAN.

Colocalization of IgG and IgA Heavy Chains with Kappa and Lambda Light Chains in Glomerular Deposits of IgA Nephropathy Patients Using High-Resolution Confocal Microscopy and Correlation with Oxford MEST-C Scores

Routine immunofluorescence microscopy of glomerular immunodeposits in IgA nephropathy shows IgA, C3, and lambda light chains, and sometimes IgG, IgM, and kappa light chains. However, a previous study using high-resolution confocal microscopy showed IgG in all IgA nephropathy cases, likely representing autoantibodies specific for galactose-deficient IgA1. Here, we used high-resolution confocal microscopy to examine the composition of glomerular immunodeposits and colocalization of kappa and lambda light chains with IgA or IgG heavy chains in kidney-biopsy samples from twenty patients with IgA nephropathy, seventeen without IgG, and nine with no or trace kappa light chains by routine immunofluorescence microscopy. IgG was detected in all biopsies by high-resolution confocal microscopy. Single-optical-plane images showed similar colocalization of IgG heavy chains with kappa and lambda light chains. Colocalization of IgA heavy chains was greater with lambda light chains than with kappa light chains. Colocalization of IgG heavy chain with kappa light chains was higher than with lambda light chains in biopsies with endocapillary hypercellularity and crescents, i.e., biopsies with active lesions. We confirmed the utility of high-resolution confocal microscopy to detect components of glomerular immunodeposits not apparent on routine immunofluorescence microscopy and for colocalization of different components, potentially clarifying the pathogenesis of IgA nephropathy.

Retrospective Analysis of the Effect of Uric Acid on the Prognosis of Immunoglobulin A Nephropathy With Stage 3-4 Chronic Kidney Disease

To investigate the effect of uric acid on the clinicopathological characteristics and prognosis of immunoglobulin A nephropathy (IgAN) in patients with stage 3-4 chronic kidney disease (CKD). The clinical and pathological data of 263 IgAN patients who had stage 3-4 CKD and who had confrimed diagosis through renal biopsy at the First Affiliated Hospital of Air Force Medical University between December 2008 and January 2020 were retrospectively collected. According to the levels of uric acid, the patients were divided into a hyperuricemia group (n=102) and a normal uric acid group (n=161), and the clinicopathological characteristics of the two groups were compared accordingly. With progression to end-stage renal disease or death as the endpoint event, the renal survival rate of the two groups was compared by the Kaplan-Meier method and the relationship between uric acid and the prognosis was analyzed by Cox regression and LASSO regression. Compared with the normal uric acid group, the hyperuricemia group had a significantly higher proportion of male patients and patients with a history of hypertension, a significantly higher level of blood urea nitrogen, and lower levels of estimated glomerular filtration rate and high-density lipoprotein. In terms of pathology, patients in the hyperuricemia group had significantly higher proportion of glomerulosclerosis, higher mesangial hypercellularity, and higher tubular atrophy/interstitial fibrosis (P<0.05). Kaplan-Meier curve showed that there was a significant difference in renal survival rate between the two groups (P<0.0001). LASSO regression showed that high uric acid was a risk factor for the prognosis of IgAN patients with stage 3-4 CKD. Further multivariate Cox analysis showed that, compared with the normal uric acid group, the hyperuricemia group had a higher risk of incurring composite outcomes (hazard ratio [HR]=1.61, 95% confidence interval [CI]: 1.10-2.34). When uric acid was used as a continuous variable, the increase of 1 mg/dL in uric acid concentration was associated with an increased HR of 1.18 (95% CI: 1.08-1.29) for the composite outcome. High uric acid is a risk factor for poor renal prognosis in IgAN patients with stage 3-4 CKD and reducing uric acid levels may effectively improve the prognosis of high-risk IgAN patients.

Assessment of serum concentration and urinary excretion of tumor necrosis factor receptor 1 and 2 and their potential as markers of immunoglobulin A nephropathy activity.

Tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2) can be cleaved from the cell surface and circulate alone or in combination with tumor necrosis factor alpha (TNF-α). These soluble receptors may play a key role in regulating the inflammatory response. The study aimed to evaluate the role of TNFRs in regulating the inflammatory response in immunoglobulin A nephropathy (IgAN). The study included 26 patients with newly diagnosed and biopsy-confirmed IgAN and 20 healthy controls. Study material included blood and fresh urine collected the morning before kidney biopsy and therapy. The serum concentrations of TNFR1 (STNFR1) and TNFR2 (STNFR2) and urinary excretion of TNFR1 (UTNFR1) and TNFR2 (UTNFR2) were determined with immunoassay. Subsequently, the data were evaluated statistically. The STNFR1 and STNFR2 levels were higher in IgAN patients than in healthy subjects (4747.87 pg/mL and 2817.62 pg/mL compared to 2755.68 pg/mL (95% CI: from -2948.41 to -1035.97; p = 0.001) and 1437.83 pg/mL (95% CI: from -1958.50 to -419.60; p = 0.001). The power of the test was 98.5% for STNFR1 and 96% for STNFR2. Urinary concentrations only increased for TNFR1 (3551.29 compared to 2338.95 pg/mg of creatinine (Cr) (95% CI: from -2247.03 to -177.66; p = 0.023). The STNFR1 marker was characterized by a sensitivity of 73.08% and a specificity of 90.00% (p < 0.001). Our results suggest that TNFR1 and TNFR2 are good markers of TNF-α pathway activation in IgAN patients.

EIF2α/ATF4 pathway enhances proliferation of mesangial cell via cyclin D1 during endoplasmic reticulum stress in IgA nephropathy

IgA nephropathy (IgAN) is an essential cause of kidney failure and end-stage kidney disease worldwide. Mesangial hypercellularity is an important characteristic of IgAN, but the underlying mechanism remains unclear. Endoplasmic reticulum (ER) stress is a series of stress responses to restore the function of endoplasmic reticulum. We aimed to explore how ER stress functioned in kidneys of IgAN. We first examined ER stress in IgAN kidneys in vivo and in vitro, by testing the levels of ER stress associated proteins (BIP, p-eIF2α and ATF4). Our results showed that ER stress was activated in IgAN patients, mice and cell model. ER stress activation was related to the distribution of IgA deposition and the degree of mesangial proliferation. To determine the role of ER stress in mesangial cell (MC) proliferation of IgAN, we then tested the levels of ER stress and MC proliferation (cyclin D1, cell viability and cell cycle) through inhibiting ER stress associated proteins. After inhibiting ER stress associated proteins, ER stress was inactivated and cell proliferation was inhibited in MCs. We also explored the correlation between ER stress in the glomerulus and the clinical outcomes of IgAN patients in a prospective study. Patients with lower expression of p-eIF2α or ATF4 had higher rates of hematuria remission, proteinuria remission and clinical remission. In summary, our work outlines that in IgAN, ER stress mediated by eIF2α/ATF4 pathway promotes MC proliferation via up-regulating the expression of cyclin D1. Furthermore, p-eIF2α and ATF4 in the glomerulus negatively correlate with the clinical remission of IgAN patients.

Renal and cardiovascular prognostic significance of echocardiographic early diastolic mitral annular velocity in IgA nephropathy.

In chronic kidney disease (CKD), as in IgA nephropathy (IgAN), cardiovascular (CV) mortality and morbidity are many times higher than in the general population, and diastolic dysfunction (LVDD) has prognostic significance as well. Tissue Doppler Echocardiography (TDI) is another method for measuring myocardial contractility and determining diastolic dysfunction. 79 IgAN patients (age 46 ± 11years) with CKD stages 1-3 were investigated and followed for 70 ± 28.7months. Doppler echocardiography was used to measure the E (early) and A (late) waves, as well as the E wave deceleration time (EDT) during mitral inflow. TDI was used to measure early (Ea) and late (Aa) diastolic velocities (lateral and septal basal wall fragment average). From these, we calculated the E/Ea and Ea/Aa ratios. The primary combined endpoints were total mortality, major CV events, and end-stage renal disease, and the secondary endpoints were cardiovascular or renal (eGFR decreased below 15ml/min/1.73 m2 or renal replacement therapy was started). Patients with decreased Ea (< 13cm/s) had significantly more endpoints (20/42 vs. 3/37; p = 0.001) than patients with higher Ea (≥ 13cm/s). The secondary renal endpoints were also significantly higher (p = 0.004). In a multivariate model, the eGFR showed independent correlation with the E/A ratio (r = 0.466; p < 0.01), EDT (r = - 0.270; p < 0.01), Ea/Aa ratio (r = 0.455; p < 0.01), and decreased Ea (r = 0.544; p < 0.01). Independent factors influencing Ea were only EDT by uni- and multivariate regression but age and albuminuria by logistic regression. Decreased Ea measured by TDI seems to be an eligible factor to predict the prognosis of IgA nephropathy. The decreased Ea may be a helpful parameter to identify high-risk CKD patients.

Candidate Genes for IgA Nephropathy in Pediatric Patients: Exome-Wide Association Study.

IgA nephropathy (IgAN) is an autoimmune disorder which is believed to be non-monogenic. We performed an exome-wide association study of 70 children with IgAN and 637 healthy donors. The HLA allele frequencies were compared between the patients and healthy donors from the bone marrow registry of the Pirogov University. We tested 78,020 gene markers for association and performed functional enrichment analysis and transcription factor binding preference detection. We identified 333 genetic variants, employing three inheritance models. The most significant association with the disorder was observed for rs143409664 (PRAG1) in the case of the additive and dominant models (PBONF = 1.808 × 10-15 and PBONF = 1.654 × 10-15, respectively), and for rs13028230 (UBR3) in the case of the recessive model (PBONF = 1.545 × 10-9). Enrichment analysis indicated the strongly overrepresented "immune system" and "kidney development" terms. The HLA-DQA1*01:01:01G allele (p = 0.0076; OR, 2.021 [95% CI, 1.322-3.048]) was significantly the most frequent among IgAN patients. Here, we characterized, for the first time, the genetic background of Russian IgAN patients, identifying the risk alleles typical of the population. The most important signals were detected in previously undescribed loci.

Clinical and pathological correlation between urinary exosome miR-223 and IgAN patients.

To investigate the association between urine exosome miR-223 and clinical markers with pathological severity of IgA nephropathy (IgAN) in order to offer a new perspective for the evaluation of IgAN patients. Western blotting and transmission electron microscopy were used to identify the exosomes collected and isolated from subjects' urine. qRT-PCR was then performed to determine the expression level of miR-223. Following that, the relationship between miR-223 expression, clinical markers, and the severity of pathology in IgAN patients was examined. (1) Urine can be used to isolate exosomes since its marker protein was visible by Western blotting, and its size and structure were observable using transmission electron microscopy. (2) Expression levels of miR-223 in urinary exosomes were much higher in IgAN patients than in healthy subjects, and these were also positively correlated with creatinine (Cr) (rho=0.396; p=0.006), blood urea nitrogen (BUN) (rho=0.371; p=0.011), 24-hour urinary microalbumin (24hU-mALB) (rho=0.341; p=0.036), mesangial cell proliferation (rho=0.359; p=0.014), glomerular segmental sclerosis (rho=0.417; p=0.004), cell/fibroblast crescents (rho=0.612; p=0.000), glomerulosclerosis, and renal interstitial fibrosis (rho=0.331; p=0.025). In urine exosomes, miR-223 might be considered a non-invasive biomarker for the assessment of IgAN disease progression.

Elevated Levels of IL-6 in IgA Nephropathy Patients Are Induced by an Epigenetically Driven Mechanism Modulated by Viral and Bacterial RNA

Elevated Levels of IL-6 in IgA Nephropathy Patients Are Induced by an Epigenetically Driven Mechanism Modulated by Viral and Bacterial RNA

Analysis of the Real-World Management of IgA Nephropathy (IgAN) Patients in Five European Countries

Analysis of the Real-World Management of IgA Nephropathy (IgAN) Patients in Five European Countries

Rate of Loss of eGFR and Time-Averaged Proteinuria in IgA Nephropathy (IgAN) Patients Progressing from Early-Stage Disease to Kidney Failure

Rate of Loss of eGFR and Time-Averaged Proteinuria in IgA Nephropathy (IgAN) Patients Progressing from Early-Stage Disease to Kidney Failure

Podocyte-specific proteins in urinary extracellular vesicles of patients with IgA nephropathy: Vasorin and ceruloplasmin

Introduction: Urinary extracellular vesicles (uEVs) can be considered biomarkers of kidney diseases. EVs derived from podocytes may reflect podocyte damage in different glomerular diseases. IgA nephropathy (IgAN) is one of the most common forms of glomerulonephritis (GN) characterized by proteinuria and hematuria. This study aimed to analyze the uEVs of IgAN patients to understand the pathophysiological processes of the disease at the protein level. Methods: Patients with GN [biopsy-proven IgAN (n = 16) and membranous glomerulonephritis (MGN, n = 16)], and healthy controls (n = 16) were included in this study. The uEVs were extracted, characterized, and analyzed to evaluate the protein levels of candidate markers of IgAN, including vasorin precursor, aminopeptidase N, and ceruloplasmin by western-blot analysis. Results: Higher levels of both podocytes and EVs-related proteins were observed in the pooled urine samples of GN patients compared to the healthy controls. In IgAN patients, uEV-protein levels of vasorin were statistically lower while levels of ceruloplasmin were significantly higher compared to MGN (P = 0.002, P = 0.06) and healthy controls, respectively (P = 0.020, P= 0.001). Conclusion: Different levels of the studied proteins in uEVs may indicate podocyte injury and represent a direct association with the pathology of IgAN and MGN.

Kidney outcomes associated with haematuria and proteinuria trajectories among patients with IgA nephropathy in real-world clinical practice: The Japan Chronic Kidney Disease Database.

Among patients with Immunoglobulin A (IgA) nephropathy, we aimed to identify trajectory patterns stratified by the magnitude of haematuria and proteinuria using repeated urine dipstick tests, and assess whether the trajectories were associated with kidney events. Using a nationwide multicentre chronic kidney disease (CKD) registry, we analysed data from 889 patients with IgA nephropathy (mean age 49.3 years). The primary outcome was a sustained reduction in eGFR of 50% or more from the index date and thereafter. During follow-up (median 49.0 months), we identified four trajectories (low-stable, moderate-decreasing, moderate-stable, and high-stable) in both urine dipstick haematuria and proteinuria measurements, respectively. In haematuria trajectory analyses, compared to the low-stable group, the adjusted hazard ratios (HRs) (95% confidence interval [CI]) for kidney events were 2.59 (95% CI, 1.48-4.51) for the high-stable, 2.31 (95% CI, 1.19-4.50) for the moderate-stable, and 1.43 (95% CI, (0.72-2.82) for the moderate-decreasing groups, respectively. When each proteinuria trajectory group was subcategorized according to haematuria trajectories, the proteinuria group with high-stable and with modest-stable haematuria trajectories had approximately 2-times higher risk for eGFR reduction ≥50% compared to that with low-stable haematuria trajectory. Assessments of both haematuria and proteinuria trajectories using urine dipstick could identify high-risk IgA nephropathy patients.

C5a enhances Vδ1 T cells recruitment via the CCL2-CCR2 axis in IgA nephropathy

BackgroundMucosal immune-associated γδ T cells have been implicated in IgA nephropathy (IgAN). However, the involvement of Vδ1 T cells, the major γδ T cells subtype, in renal damage and the mechanism underlying their migration from peripheral blood to kidney in IgAN remain unclear. MethodsClinical data from IgAN patients and healthy controls (HC) were analyzed. Phenotypes and chemokine receptors of γδ T cell were compared between IgAN patients and HC. Immunohistochemistry and immunofluorescence were performed to assess the infiltration of γδ T cell subsets and the expression of chemokine in renal tissues. In vitro, C5a was used to stimulate the human glomerular mesangial cells (HMCs) and chemotaxis experiment was used to examine Vδ1 T cells migration. Correlation between Vδ1 T cells and related clinical indicators were analyzed. ResultsIgAN patients exhibited decreased Vδ1 T cell in blood but increased levels in kidneys compared to HC. Increased CCR2-expressing Vδ1 T cells and serum level of CCL2 were observed in IgAN patients. CCL2 co-localized with CCR2 in HMCs of IgAN. In vitro, C5a enhanced Vδ1 T cells recruitment by HMCs through CCL2-CCR2 axis. Importantly, circulating Vδ1 T cell levels showed a negatively correlated with both the urinary protein creatinine ratio (UACR) and 24-hour urine protein (UP). Moreover, kidney infiltration of Vδ1 cells positively correlated with UACR, UP, mesangial hyperplasia and renal tubule atrophy/interstitial fibrosis in IgAN. ConclusionsC5a-induced production of CCL2 by HMCs facilitates Vδ1 T cells recruitment via the CCL2-CCR2 axis, contributing to renal damage in IgAN.

Clinical significance of massive proteinuria in primary IgA nephropathy with and without nephrotic syndrome: a single center cohort study

Background Both primary IgA nephropathy (IgAN) with and without nephrotic syndrome (NS) can present massive proteinuria (24-h urinary protein ≥3.5 g/d). The clinical significance of massive proteinuria may be different in the two entities and needs further research. Methods Data of 1870 patients with biopsy-proven IgAN in our hospital from January 2011 to December 2022 was retrospectively reviewed. A total of 242 IgAN patients with massive proteinuria were enrolled. Patients who presented with nephrotic syndrome at renal biopsy were included in the IgAN with NS cohort (IgAN-NS). The IgAN with nephrotic-range proteinuria cohort (IgAN-NR) consisted of 1:1 matched cases from the remaining according to age, gender, estimated glomerular filtration rate (eGFR) at baseline, and follow-up time. The clinical and pathological characteristics between the two cohorts were analyzed. Results The IgAN-NS had a significantly higher proteinuria level than the IgAN-NR (p < .001). Cluster analysis revealed that proteinuria was associated with lipids in IgAN-NS, while it was associated with inflammatory indicators in IgAN-NR. When the complete remission of proteinuria (CR) was not achieved, the Kaplan–Meier analysis showed the prognosis of IgAN-NS was significantly worse than that of IgAN-NR (p = .04). Then, our GLMM model and line chart showed that the serum albumin level of the IgAN-NR was always evidently higher than that of the IgAN-NS while the significant difference in urinary albumin/creatinine ratio between the two cohorts gradually disappeared during the short-term follow-up (1 year). Moreover, the Cox regression analysis showed that the increased serum albumin was an independent protective factor for the poor outcomes (eGFR decreased from the baseline ≥ 30% continuously or reached end-stage renal disease [ESRD]). Conclusion The IgAN-NS had poorer clinicopathologic manifestation than IgAN-NR, including severer massive proteinuria. When the CR was not achieved, the prognosis of IgAN-NS was inferior to that of the IgAN-NR.

Tubulo-interstitial inflammation increases the risk of graft loss after the recurrence of IgA nephropathy.

Immunoglobulin A nephropathy (IgAN) is the most frequent recurrent disease in kidney transplant recipients and its recurrence contributes to reducing graft survival. Several variables at the time of recurrence have been associated with a higher risk of graft loss. The presence of clinical or subclinical inflammation has been associated with a higher risk of kidney graft loss, but it is not precisely known how it influences the outcome of patients with recurrent IgAN. We performed a multicentre retrospective study including kidney transplant recipients with biopsy-proven recurrence of IgAN in which Banff and Oxford classification scores were available. 'Tubulo-interstitial inflammation' (TII) was defined when 't' or 'i' were ≥2. The main endpoint was progression to chronic kidney disease (CKD) stage 5 or to death censored-graft loss (CKD5/DCGL). A total of 119 kidney transplant recipients with IgAN recurrence were included and 23 of them showed TII. Median follow-up was 102.9months and 39 (32.8%) patients reached CKD5/DCGL. TII related to a higher risk of CKD5/DCGL (3years 18.0% vs 45.3%, log-rank 7.588, P=.006). After multivariate analysis, TII remained related to the risk of CKD5/DCGL (HR 2.344, 95% CI 1.119-4.910, P=.024) independently of other histologic and clinical variables. In kidney transplant recipients with IgAN recurrence, TII contributes to increasing the risk of CKD5/DCGL independently of previously well-known variables. We suggest adding TII along with the Oxford classification to the clinical variables to identify recurrent IgAN patients at increased risk of graft loss who might benefit from intensified immunosuppression or specific IgAN therapies.