Urinary IgG Research Articles

Urinary IgG, serum CX3CL1 and miRNA-152-3p: as predictors of nephropathy in Egyptian type 2 diabetic patients

ABSTRACT The purpose of this study was to assess the role of urinary IgG, serum CX3CL1 and miRNA 152–3p levels as predictors of nephropathy in type 2 Egyptian diabetic patients. Sixty type 2 diabetic patients and twenty healthy controls were enrolled in a cross-sectional study. Then they were grouped into: three groups based upon urine albumin excretion (UAE). The expression of miRNA 152–3p in serum was measured using quantitative polymerase chain reaction (RTq-PCR). Serum CX3CL1 and urinary IgG concentrations were measured by ELISA. RTq-PCR revealed that serum miRNA-152-3p levels in patients were significantly higher than in controls. There was significant differences between group with normoalbuminuria and groups with diabetic nephropathy DN as regard to age, duration of nephropathy, Albumin/Creatinine ratio (A/C ratio), creatinine, urine IgG, CX3CL1 and HbA1c. In diabetic patients, there was a significant positive correlation between miRNA-152-3p levels and disease duration only as well as significant positive correlations between urinary IgG levels and age, disease duration, serum creatinine, A/C ratio, and urea. Positive correlation between serum fractalkine CX3CL1 level and age, duration of disease, urea, creatinine, A/C ratio, HbA1C and IgG in patient with DN. Serum CX3CL1 level, urinary IgG were significantly increased with the progress of nephropathy so these integrated biomarkers could be used as good predictors for early identification of nephropathy. But miRNA- 152-3p has inadequate prognostic indicator for ESRD progression.

Urinary Transferrin and IgG Are Significant and Early Markers of Tubulointerstitial Lesions in Patients with IgA Nephropathy

Urinary Transferrin and IgG Are Significant and Early Markers of Tubulointerstitial Lesions in Patients with IgA Nephropathy

Antigen-Specific Urinary Immunoglobulin in Reservoir Hosts of Leptospirosis.

Domestic and wildlife animal species act as reservoir hosts of leptospirosis, a global zoonotic disease affecting more than 1 million people annually and causing significant morbidity and mortality in domestic animals. In contrast to incidental hosts which present with an array of clinical manifestations, reservoir hosts are typically asymptomatic and can shed leptospires from chronically infected kidneys via urine for extended periods of time. Renal excretion of leptospires occurs despite evidence of a humoral and cellular immune response and is reflective of the unique biological equilibrium that exists between certain animal species and specific serovars of Leptospira. Here, we demonstrate that urinary excretion of leptospires is accompanied by the presence of antigen-specific urinary immunoglobulin. In rats experimentally infected with L. interrogans serovar Copenhageni using the intraperitoneal or conjunctival route of inoculation, urinary immunoglobulin (Ig) G specific for protein antigens was detectable within 1 week. Rat urinary IgG was not bound to urinary-derived leptospires. In cattle that were naturally exposed to, and infected with, L. borgpetersenii serovar Hardjo, urinary IgA specific for protein antigens was detected. Collectively, these results demonstrate that urinary excretion of immunoglobulin specific for leptospires is a hallmark of reservoir hosts of infection.

Genetic background determines renal response to chronic lithium treatment in female mice.

Chronic lithium treatment for bipolar disease causes mainly side effects in the kidney. A subset of lithium users develops nephrogenic diabetes insipidus (NDI), a urinary concentrating disorder, and chronic kidney disease (CKD). Age, lithium dose, and duration of treatment are important risk factors, whereas genetic background might also play an important role. To investigate the role of genetics, female mice of 29 different inbred strains were treated for 1 year with control or lithium chow and urine, blood, and kidneys were analyzed. Chronic lithium treatment increased urine production and/or reduced urine osmolality in 21 strains. Renal histology showed that lithium increased interstitial fibrosis and/or tubular atrophy in eight strains, whereas in none of the strains glomerular injury was induced. Interestingly, lithium did not elevate urinary albumin-creatinine ratio (ACR) in any strain, whereas eight strains even demonstrated a lowered ACR. The protective effect on ACR coincided with a similar decrease in urinary IgG levels, a marker of glomerular function, whereas the adverse effect of lithium on interstitial fibrosis/tubular atrophy coincided with a severe increase in urinary β2-microglobulin (β2M) levels, an indicator of proximal tubule damage. Genetic background plays an important role in the development of lithium-induced NDI and chronic renal pathology in female mice. The strong correlation of renal pathology with urinary β2M levels indicates that β2M is a promising biomarker for chronic renal damage induced by lithium.

P–340 Novel non-invasive diagnostic options for endometriosis - based on glycome analysis

Abstract Study question Could glycosylation changes on serum and/or urine glycoproteins be suitable biomarkers for the non-invasive diagnosis of endometriosis? Summary answer The glycosylation pattern on serum and urine glycoproteins differed significantly in endometriosis patients compared to controls, suggesting a novel role as biomarkers of the disease. What is known already There is little published on endometriosis and glycosylation, and most of the studies are conducted with tissue or peritoneal fluid samples, collected by invasive means. An Iraqi study draws attention to the importance of serum sialylation, which is dramatically changed in endometriosis patients after zoladex therapy, indicating that changes in serum sialylation may be a new biomarker of the disease. While glycosylation of urine in endometriosis has not been studied so far, in a study of endometrial cancer, the urinary level of two glycoproteins was significantly increased in the patients compared to the control group. Study design, size, duration This was a prospective study. In this basic research project, serum and urine samples were collected for glycome analysis in women with and without endometriosis, as diagnosed at laparoscopy. Glycated haemoglobin (HbA1c), fasting glucose levels as well as hormone levels were also collected from the patients to link our glycomic findings with metabolic and hormone profiles. The study was approved by the Research and Ethics Committee of the National Maternity Hospital, Dublin (EC19.2018). Participants/materials, setting, methods Samples from 24 cases of endometriosis (patients without previous anti-inflammatory or hormonal therapy, endometriosis was confirmed by laparoscopy) and 27 control patients (patients without endometriosis) were processed to analyse N-glycans (total serum), urine glycoproteins, and IgG. The pre-processed, PNGase F-digested serum and urine samples were labelled with fluorescent tag and then analysed by mass spectrometry, ultra-performance liquid chromatography (UPLC) in combination with exoglycosidase digestions and Glycostore (https://glycostore.org/). Main results and the role of chance Glycosylation on total serum and urine glycoproteins and IgG was investigated and differed in endometriosis compared to controls. The N-glycome from the total glycoproteins in serum and urine was also different. The proportion of the galactosylation and sialylation differed between urine and serum IgG and these alterations have an impact on the IgG function. Our preliminary data indicate, that there is an increase in alpha 2–3 sialylation, galactosylation, and fucosylation on urine glycans from endometriosis patients compared to the control pool. Urine is a good source of biomarkers as it can be collected non-invasively. Our group is the first to have developed a protocol for the recovery of N-glycans in urine and to have identified the total N-glycome in urine. The urine N-glycome contains mostly complex N-glycans and also some oligomannosylated and hybrid glycans. Our results may lead to non-invasive biomarkers for the diagnosis of endometriosis and the monitoring of the disease. Limitations, reasons for caution The number of participants involved in this basic research is low but this is a pilot study. A larger, validation study, is warranted in the future. Furthermore, the follow-up of treated patients also would be an interesting field of research. Wider implications of the findings: Glycomics may be a potent source of biomarkers of endometriosis, with a number of glyco-biomarkers already approved by the FDA. Endometriosis-associated glycomic profiles from serum and/or urine glycoproteins may represent viable targets for development of innovative non-invasive or minimally invasive diagnostics in this debilitating disease. Trial registration number Not applicable

The role of urine IgG in the progression of IgA nephropathy with a high proportion of global glomerulosclerosis.

IgA nephropathy (IgAN), the most common glomerulonephritis in the world, is an important cause of end-stage renal disease (ESRD). It is necessary to explore new prognostic markers for predicting the activity and progress of IgAN. There are few studies on new prognostic markers in IgAN patients with high proportion of glomerulosclerosis. This study aims to explore the value of urine IgG in predicting the prognosis of IgAN patients. The primary end point of this retrospective study was a composite event with a reduction in estimated glomerular filtration rate (eGFR) of ≥ 50% or ESRD or death. This study assessed the association between urinary IgG and clinicopathological parameters, as well as the prognosis of a high proportion of patients with global glomerulosclerotic IgAN. This study included 105 IgAN patients with high proportion of global glomerulosclerotic. The level of urinary protein IgG was significantly correlated with clinical prognostic factors. The level of urinary protein IgG was positively correlated with urinary protein excretion (rs = 0.834, P < 0.001), CRP (rs = 0.375, P < 0.001), and C4 (rs = 0.228, P = 0.019), and negatively correlated with eGFR (rs = - 0.307, P = 0.001). In addition, the level of urinary IgG increased with the increase of tubulointerstitial injury rate, which was positively correlated with endothelial cell proliferation and crescent (all P < 0.05). Prognostic analysis using the Cox proportional hazard regression model and Kaplan-Meier survival curve further determined that urine IgG is an independent risk factor for the prognosis of IgAN with high proportion of global glomerulosclerosis. This study determined that urine IgG can be used as a useful predictor of the prognosis of IgAN patients with high proportion global glomerulosclerosis. The mechanism of urine IgG trends in IgAN with high proportion of glomerulosclerosis needs further study.

Analysis of Daily Variation for 3 and for 30 Days of Parasite-Specific IgG in Urine for Diagnosis of Strongyloidiasis by Enzyme-Linked Immunosorbent Assay

Recent work has found urine analysis to be as sensitive as serology for diagnosis of strongyloidiasis. Here, we examined the daily variation of Strongyloides-specific IgG in urine by qualitative and quantitative ELISA and its effects on diagnostic accuracy and reliability. In the first part of the study, matched urine and fecal samples were collected from project participants in northeast Thailand for three consecutive days. Urine samples were analyzed for Strongyloides-specific IgG by ELISA using Strongyloides ratti as the antigen source. Performance of urine ELISA was compared with parasitological diagnosis by agar plate culture technique (APCT) and formalin-ethyl acetate concentration technique (FECT). In the second part of the study, urine IgG levels were compared daily for thirty consecutive days.The prevalence of Strongyloides infection, as measured by urine ELISA for three consecutive days, was significantly higher than that found using parasitological methods (63.1% vs. 22%). There was slight daily variation in prevalence estimates according to urine ELISA while there were significant variations according to parasitological examination methods over three consecutive days. For the 3-day experiment, urine ELISA had 83-86% diagnostic sensitivity when compared with the fecal examination method or with a composite standard (combined results from fecal examination methods (APCT or FECT) and/or urine ELISA). The levels of parasite-specific IgG in urine were stable throughout both the 3-day and the 30-day studies.In conclusion, diagnosis of strongyloidiasis by urine ELISA is more sensitive than by fecal methods, with minimal daily variation for qualitative and quantitative diagnosis. Urine ELISA has potential for clinical diagnosis and population screening of strongyloidiasis.

Clinical features of neurogenic bladder with vesicoureteral reflux in children

OBJECTIVE To study the clinical features of vesicoureteral reflux (VUR) in children with neurogenic bladder (NB), and to provide a reference for its early diagnosis and treatment. METHODS Clinical data were collected from 26 children with NB and urinary tract infection who were admitted to the Department of Pediatric Nephrology from January 2014 to December 2019. According to the presence or absence of VUR, the children were divided into a VUR group with 11 children and a non-VUR group with 15 children. Clinical features were compared between the two groups. RESULTS Compared with the non-VUR group, the VUR group had a significantly higher proportion of children with non-Escherichia coli urinary tract infection, hydronephrosis (the severity of hydronephrosis increased with the grade of VUR), abnormal 99mTc-DMSA renal scanning findings, elevated ratios of urinary albumin, urinary IgG and urinary transferrin to creatinine, increased residual urine volume, and increased detrusor leak point pressure (P < 0.05). CONCLUSIONS When NB children have the clinical manifestations of non-Escherichia coli urinary tract infection, hydronephrosis, abnormal 99mTc-DMSA renal scanning findings, glomerular proteinuria, increased bladder residual urine volume, and high detrusor leak point pressure, such children may already have VUR, and so diagnosis and intervention should be performed as early as possible.

Continuous hypergammaglobulinemia and proteinuria after the recovery of the visceral Leishmaniasis: a case report

BackgroundKidney involvement of visceral Leishmaniasis is previously reported, but knowledge is limited. Hypergammaglobulinemia is common in visceral leishmaniasis patients. Whether hypergammaglobulinemia after leishmaniasis depletion can cause kidney injury is not well reported yet.Case presentationWe reported a patient who recovered from visceral Leishmaniasis but showed persistent hypergammaglobulinemia and elevated urinary protein. Kidney biopsy showed glomerular hypertrophy with mild segmental mesangial proliferation without tubulointerstitial involvement in light microscopy. No immune complex deposit was found in the mesangial area by neither immunofluorescent staining nor electronic microscope. Increased lysosomes were observed in proximal tubules by electronic microscope. Valsartan was administered to decrease urinary protein, and no immune-suppressive therapy was added. The urinary protein and serum IgG level gradually dropped, and serum creatinine level remained stable during three- month follow up.ConclusionsHypergammaglobulinemia is unlikely to cause renal structural or functional damage in the short term. Angiotensin blockade significantly reduced urine protein, with a minor effect on IgG elimination.

Glomerular filtration barrier dysfunction in a self-limiting, RNA virus-induced glomerulopathy resembles findings in idiopathic nephrotic syndromes

Podocyte injury has recently been described as unifying feature in idiopathic nephrotic syndromes (INS). Puumala hantavirus (PUUV) infection represents a unique RNA virus-induced renal disease with significant proteinuria. The underlying pathomechanism is unclear. We hypothesized that PUUV infection results in podocyte injury, similar to findings in INS. We therefore analyzed standard markers of glomerular proteinuria (e.g. immunoglobulin G [IgG]), urinary nephrin excretion (podocyte injury) and serum levels of the soluble urokinase plasminogen activator receptor (suPAR), a proposed pathomechanically involved molecule in INS, in PUUV-infected patients. Hantavirus patients showed significantly increased urinary nephrin, IgG and serum suPAR concentrations compared to healthy controls. Nephrin and IgG levels were significantly higher in patients with severe proteinuria than with mild proteinuria, and nephrin correlated strongly with biomarkers of glomerular proteinuria over time. Congruently, electron microcopy analyses showed a focal podocyte foot process effacement. suPAR correlated significantly with urinary nephrin, IgG and albumin levels, suggesting suPAR as a pathophysiological mediator in podocyte dysfunction. In contrast to INS, proteinuria recovered autonomously in hantavirus patients. This study reveals podocyte injury as main cause of proteinuria in hantavirus patients. A better understanding of the regenerative nature of hantavirus-induced glomerulopathy may generate new therapeutic approaches for INS.

Arsenic Exposure and Association with Hepatitis E IgG Antibodies

Arsenic is a known toxic chemical, has immuno-modulatory properties, and can change the susceptibility of infection in humans. Acute hepatitis E is an infectious disease; it can be self-limiting, but in severe cases, can cause acute-on-chronic liver failure. The presence of IgG anti-HEV (hepatitis E IgG antibody) in blood represents a past hepatitis E infection in an individual. Very few studies have investigated the association between arsenic levels and hepatitis E seroconversion in humans. The primary objective of this study was to assess the relationship between total urinary arsenic and speciated urinary arsenic (urinary arsenous acid, urinary arsenic acid, urinary arsenobetaine, urinary arsenocholine, urinary dimethylarsinic acid, urinary monomethylarsonic acid) and the presence of IgG anti-HEV. The 2011-2012, 2013-2014, and 2015-2016 National Health and Nutrition Examination Survey (NHANES) III data sets were analyzed, with participants aged 20 years and older (n = 7061). We used weighted logistic regression to determine the association between total and speciated urinary arsenic concentrations and IgG anti-HEV. For each analyte considered, a separate weighted logistic regression model was fitted. Each of these models regressed log-transformed analyte levels on the log-odds of the presence of IgG Anti-HEV. To evaluate the relationships between the urinary arsenic measurements, pairwise Pearson correlation coefficients were determined for each of the urinary arsenic measurements. Of the human subjects included, 6628 (93.9%) were negative for IgG Anti-HEV while 433 (6.1%) were positive for IgG anti-HEV. Total urinary arsenic was associated with 1.161 times greater odds of IgG anti-HEV (95% CI: [1.035, 1.303]) for each unit increase in concentration on a log-scale. For speciated urinary arsenic measurements, the odds ratios and 95% CI’s were: arsenobetanine 1.168 [1.075, 1.270], arsenocholine 1.201 [0.944, 1.529], dimethylarsinic acid 1.183 [1.009, 1.386], monomethylacrsonic acid 1.095 [0.915, 1.310], aresnous acid 0.907 [0.762, 1.079], and arsenic acid 1.951 [0.905, 4.209]. Our analysis indicates that total urinary arsenic, arsenobetanine, and dimethylarsinic acid are significantly associated with the odds of the presence of IgG anti-HEV. Future prospective studies are required to evaluate the association between hepatitis E infection and arsenic exposures.

Renoprotective effects of artemisinin and hydroxychloroquine combination therapy on IgA nephropathy via suppressing NF-κB signaling and NLRP3 inflammasome activation by exosomes in rats

Immunoglobulin A nephropathy (IgAN) is an autoimmune kidney disease with complex pathogenesis leading to end-stage renal damage. The prime pathological characteristics of IgAN are IgA immune complexes deposition accompany with mesangial cell proliferation and urine protein elevation. Artemisinin (ART) is extracted from traditional Chinese medicine Artemisia annua L. Hydroxychloroquine (HCQ) is a classical antimalarial drug applied in the treatment of autoimmune diseases. Both of them possess anti-inflammatory and immunomodulatory properties. The purpose of this research was to investigate the pharmacological effects of ART combined with HCQ (AH) and discuss thoroughly the potential molecular mechanisms in IgAN. In vivo, our results demonstrated that AH could efficiently ameliorate kidney damage by improving kidney dysfunction and reducing the levels of 24 h urine protein, IgA and IgG immune complexes deposition in glomerulus of IgAN rats. Interestingly, AH obviously promoted the secretion of exosomes in renal tissues, inhibited the expressions of nuclear factor-κB (NF-κB) signaling and NLRP3 inflammasome-related proteins, including IκB-α, p-p65, NLRP3, ASC, IL-1β and caspase-1 in IgAN rats. In vitro, further mechanistic study illustrated that exosomes derived from human renal tubular epithelial cells (HK-2) were significantly enhanced by AH, which could be utterly taken up in human mesangial cells (HMCs) and inhibited the activation of NF-κB pathway and NLRP3 inflammasome after AH intervention. However, GW4869 interdicted the promotive effect of AH on exosomes from HK-2 cells and the suppression of exosomes on NF-κB/NLRP3 activation in HMCs. Taken together, this study demonstrated that there was an inhibitory effect of AH therapy on NF-κB/NLRP3 signaling via mediating exosomes release in IgAN rats, which provided an alternative approach for IgAN treatment.

Influenza Virus-Like Particles Presenting both Toxoplasma gondii ROP4 and ROP13 Enhance Protection against T. gondii Infection.

Rhoptry organelle proteins (ROPs) secreted by Toxoplasma gondii (T. gondii) play a critical role during parasite invasion into host cells. In this study, virus-like particles (VLPs) vaccines containing ROP4 and/or ROP13 together with influenza M1 were generated. ROP4+ROP13 VLPs were produced by combining ROP4 VLPs with ROP13 VLPs, and ROP(4 + 13) VLPs by co-infecting insect cells with recombinant baculovirus expressing ROP4 or ROP13. Mice intranasally immunized with ROP(4 + 13) VLPs showed significantly higher levels of IgG, IgG1, IgG2a and IgA antibody responses in sera compared to ROP4+ROP13VLPs. Upon challenge infection by oral route, mice immunized with ROP(4 + 13) VLPs elicited higher levels of IgG and IgA antibody responses in fecal, urine, intestine and vaginal samples as well as CD4+ T, CD8+ T cells, and germinal center B cell responses compared to other type of vaccines, ROP4 VLPs, ROP13 VLPs, and ROP4+ROP13 VLPs. ROP(4 + 13) VLPs vaccination showed a significant decrease in the size and number of cyst in the brain and less body weight loss compared to combination ROP4+ROP13 VLPs upon challenge infection with T. gondii ME49. These results indicated that the ROP(4 + 13) VLPs vaccination provided enhanced protection against T. gondii infection compared to ROP4+ROP13 VLPs, providing an important insight into vaccine design strategy for T. gondii VLPs vaccines.

Association of endotoxaemia & gut permeability with complications of acute pancreatitis: Secondary analysis of data.

Background & objectives:In acute pancreatitis (AP) gut barrier dysfunction is considered as an important predisposing factor leading to increased intestinal permeability (IP). In this study a pooled analysis of data published in our previous four studies on various aspects of gut permeability and endotoxaemia in patients with AP was attempted to find an association between increased IP and severity of disease and associated complications.Methods:This study was a pooled analysis of data of four previously published prospective studies on AP. Gut permeability, assessed by lactulose/mannitol excretion in urine and endotoxin core antibodies type IgG and IgM (EndoCab IgG and IgM) were measured on days zero and seven (D0 and D7) of admission. All patients received standard treatment of AP. We studied whether IgG and IgM anti-endotoxin titres and lactulose-mannitol ratio (LMR) at admission and D7 were associated with organ failure, infection and mortality.Results:The titres of anti-endotoxin IgG and IgM were lower in all patients of AP (n=204), both in mild AP (n=24) and severe AP (n=180) in the first week, compared to controls (n=15). There was no significant difference in serum IgG and IgM anti-endotoxin levels and LMR at baseline and at D7 among patients with organ failure, infection and mortality.Interpretation & conclusions:Our findings showed that serum IgG and IgM anti-endotoxin titres and LMR at admission and at day 7 were not associated with organ failure, infection, and death of patients with AP.

Correlation between endocapillary proliferative and nephrotic-range proteinuria in children with Henoch-Schönlein purpura nephritis.

The endocapillary proliferative (EP) lesion is not included in theInternational Study of Kidney Disease in Children(ISKDC) pathological classification of Henoch-Schönlein purpura nephritis (HSPN). The main objective of the study was to determine the pathological importance of EP in the development of proteinuria in children with Henoch-Schönlein purpura nephritis (HSPN). The pathological features of 148 HSPN children with nephrotic-range proteinuria were investigated retrospectively. Urinary IgG, transferrin, and albumin levels were measured by immunonephelometry. The correlations between EP lesion and 24-h proteinuria, urinary IgG, urinary transferrin, and urinary albumin were analyzed. Renal biopsy specimens were immunohistochemically stained for nephrin and podocalyxin. Of the total 581 cases of children with HSPN who underwent renal biopsy, 148 cases (25.5%) presented with nephrotic-range proteinuria. The pathological types of HSPN with nephrotic-range proteinuria were categorized as IIb, IIIa, IIIb, IIIb with diffuse EP, IVb, pure focal EP type, and pure diffuse EP type. Among these types, pure diffuse EP type accounted for 7.4%. The levels of 24-h proteinuria and urinary albumin were the highest in pure diffuse EP type among all pathological types, and the percentage of EP correlated with 24-h proteinuria and urinary albumin levels. 24-h proteinuria was significantly higher in pure diffuse EP type relative to HSPN IIb type, and significantly higher in IIIb with EP, compared with HSPN IIIb. Nephrin, but not podocalyxin, was downregulated in EP segment. EP is an independent pathogenic factor in HSPN with nephrotic-range proteinuria. Downregulation of nephrin in EP segment is a potential molecular mechanism of nephrotic-range proteinuria. Albumin is the major urinary protein component in HSPN with EP.

Markers of Glomerular and Tubular Damage in the Early Stage of Kidney Disease in Type 2 Diabetic Patients.

Diabetic kidney disease develops in half of genetically predisposed patients with type 2 diabetes (T2DM). Early diagnosis of kidney damage and nephroprotective treatment are the ways of preventing the disease progression. Our aim was to evaluate selected laboratory markers of glomerular and tubular damage in T2DM patients with early stages of chronic kidney disease (G1/G2, A1/A2) for their associations with A2 albuminuria and early decline in the estimated glomerular filtration rate (eGFR). Among 80 T2DM patients with median eGFR of 92.4 ml/min/1.73 m2 and median urinary albumin to creatinine ratio (uACR) of 4.69 mg/g, 19 had uACR > 30 mg/g (A2). Higher serum cystatin C, serum and urine neutrophil gelatinase associated lipocalin (NGAL), urine kidney injury molecule 1 (KIM-1), detectable urine transferrin and IgG, and lower serum uromodulin significantly predicted A2 albuminuria, urine KIM-1/creatinine ratio, and IgG being the best predictors. Albuminuria, urine NGAL/creatinine, and IgG correlated with diabetes duration. Albuminuria, urine NGAL, transferrin, IgG, and uromodulin correlated with diabetes control. In a subgroup of 29 patients, retrospective data were available on changes in eGFR and uACR over one year. Decline in eGFR was observed in 17 patients and increase in uACR in 10 patients. Serum and urine NGAL correlated with eGFR changes. Higher urine NGAL, KIM-1/creatinine ratio, and detectable IgG were significantly associated with the increase in uACR. Widely available markers, serum cystatin C, urine IgG, transferrin, and NGAL, may help in early assessment of kidney disease in T2DM patients; however, large prospective studies are needed to confirm the conclusion.

Diagnostic performance of urinary IgG antibody detection: A novel approach for population screening of strongyloidiasis.

The diagnosis of strongyloidiasis by coprological methods has a low sensitivity, underestimating the prevalence of Strongyloides stercoralis in endemic areas. Serodiagnostic tests for strongyloidiasis have shown robust diagnostic properties. However, these methods require a blood draw, an invasive and labor-intensive sample collection method, especially in the resource-limited settings where S. stercoralis is endemic. Our study examines a urine-based assay for strongyloidiasis and compares its diagnostic accuracy with coprological and serological methods. Receiver operating characteristic (ROC) curve analyses determined the diagnostic sensitivity (D-Sn) and specificity (D-Sp) of the urine ELISA, as well as estimates its positive predictive value and diagnostic risk. The likelihood ratios of obtaining a positive test result (LR+) or a negative test result (LR-) were calculated for each diagnostic positivity threshold. The urine ELISA assay correlated significantly with the serological ELISA assay for strongyloidiasis, with a D-Sn of 92.7% and a D-Sp of 40.7%, when compared to coprological methods. Moreover, the urine ELISA IgG test had a detection rate of 69%, which far exceeds the coprological method (28%). The likelihood of a positive diagnosis of strongyloidiasis by the urine ELISA IgG test increased significantly with increasing units of IgG detected in urine. The urine ELISA IgG assay for strongyloidiasis assay has a diagnostic accuracy comparable to serological assay, both of which are more sensitive than coprological methods. Since the collection of urine is easy and non-invasive, the urine ELISA IgG assay for strongyloidiasis could be used to screen populations at risk for strongyloidiasis in S. stercoralis endemic areas.

Urinary IgG4 and Smad1 Are Specific Biomarkers for Renal Structural and Functional Changes in Early Stages of Diabetic Nephropathy.

Diabetic nephropathy (DN) is the major cause of end-stage kidney disease, but early biomarkers of DN risk are limited. Herein we examine urinary IgG4 and Smad1 as additional early DN biomarkers. We recruited 815 patients with type 2 diabetes; 554 patients fulfilled the criteria of an estimated glomerular filtration rate (eGFR) >60 mL/min and no macroalbuminuria at baseline, with follow-up for 5 years. Patients without macroalbuminuria were also recruited for renal biopsies. Urinary IgG4 and Smad1 were determined by enzyme-linked immunoassays using specific antibodies. The specificity, sensitivity, and reproducibility were confirmed for each assay. Increased urinary IgG4 was significantly associated with lower eGFR. The level of urinary IgG4 also significantly correlated with surface density of peripheral glomerular basement membrane (Sv PGBM/Glom), whereas Smad1 was associated with the degree of mesangial expansion-both classic pathological findings in DN. Baseline eGFR did not differ between any groups; however, increases in both urinary IgG4 and Smad1 levels at baseline significantly predicted later development of eGFR decline in patients without macroalbuminuria. These data suggest that urinary IgG4 and Smad1 at relatively early stages of DN reflect underlying DN lesions and are relevant to later clinical outcomes.

Biomarkers of IgA vasculitis nephritis in children.

Henoch–Schönlein purpura is a systemic vasculitis characterized by IgA deposits, which target the skin, joints, and kidneys, among other organs. In children, prognosis is often good but little is known about biomarkers of pediatric nephritis. We hypothesized that biological markers, including cytokines, immunoglobulins, IgA-immune complexes, IgA glycosylation and neutrophil gelatinase-associated lipocalin (NGAL), may discriminate IgA vasculitis (IgAV) pediatric patients with renal involvement from those without renal involvement. Fifty children at the time of IgAV rash between 2010 and 2015 were prospectively enrolled and compared to 21 controls. All patients were assessed for clinical and biological parameters at the time of diagnosis, including the levels of cytokines, immunoglobulins, immune complexes, IgA glycosylation and NGAL in serum and urine. Among IgAV patients, 33 patients exhibited nephritis (IgAV-N) and 17 children were without nephritis (IgAV-woN). The serum level of galactose-deficient (Gd)-IgA1 (p<0.01) and the urinary concentrations of IgA, IgG, IgM, IL-6, IL-8, IL-10, IgA-IgG complexes and IgA-sCD89 complexes (p<0.001 for all) were higher in the IgAV-N patients than in the IgAV-woN patients. Among those markers, urinary IgA and IgM had the highest AUC (0.86 and 0.87 respectively, p<0.0001). This prospective cohort study furthers our understanding of the pathophysiology of IgAV. We identified biomarkers that are able to distinguish patients initially with or without nephritis. To conclude, serum Gd-IgA1 and urinary IgA, IgG, IgM, IL-6, IL-8, IL-10, and IgA-IgG and IgA-sCD89 complexes could identify IgAV pediatric patients with renal involvement at the time of diagnosis.

Value of biomarkers for predicting immunoglobulin A vasculitis nephritis outcome in an adult prospective cohort.

Henoch-Schönlein purpura, more recently renamed immunoglobulin A vasculitis (IgAV), is a systemic vasculitis characterized by IgA deposits. The current markers used to assess IgAV inaccurately evaluate the risk of nephritis occurrence and its long-term outcomes. The current study assessed biomarkers of nephritis outcomes. This French multicentre prospective study enrolled 85 adult patients at the time of disease onset. Patients were assessed for clinical and biological parameters and re-examined after 1 year. Immunoglobulins, cytokines, IgA glycosylation, IgA complexes and neutrophil gelatinase-associated lipocalin (NGAL) concentrations were assessed in blood and urine. We identified 60 patients with IgAV-related nephritis (IgAV-N) and 25 patients without nephritis (IgAV-woN). At the time of inclusion (Day 1), the serum levels of galactose-deficient IgA1 (Gd-IgA1) and urinary concentrations of IgA, IgG, IgM, NGAL, interleukin (IL)-1β, IL-6, IL-8, IL-10, IgA-IgG and IgA-sCD89 complexes were higher in the IgAV-N patients than in the IgAV-woN patients (P < 0.005 for all comparisons). After follow-up (1 year), 22 patients showed a poor outcome. Among the tested markers, urine IgA at disease onset adequately reclassified the risk of poor outcome over conventional clinical factors, including estimated glomerular filtration rate, proteinuria and age (continuous net reclassification improvement = 0.72, P = 0.001; integrated discrimination improvement = 0.13, P = 0.009) in IgAV patients. Taken together, these results showed that serum Gd-IgA1 and urinary IgA, IgG, IgM, NGAL, IL-1β, IL-6, IL-8, IL-10, IgA-IgG and IgA-sCD89 complexes were associated with nephritis in IgAV patients. Urinary IgA level may improve patient risk stratification for poor outcome.