Coexistence of Different Circulating Anti-Podocyte Antibodies in Membranous Nephropathy (original) (raw)
Membranous Nephropathy Associated With IgG4-Related Disease
American Journal of Kidney Diseases, 2011
Immunoglobulin G4 (IgG4)-related systemic disease is a rare condition characterized by high levels of circulating IgG4 and IgG4-positive plasma cell infiltrates in various organs, including the pancreas, salivary glands, biliary tract, liver, lung, and kidney. We describe a case of a 54-year-old man with IgG4-related systemic disease presenting with autoimmune pancreatitis and Mikulicz disease. Steroid therapy decreased circulating IgG4 levels and promoted regression of clinical signs. Thereafter, an increase in serum IgG4 values was followed by the occurrence of nephrotic-range proteinuria. Kidney biopsy showed membranous nephropathy with no IgG4-positive cell infiltrates. A search for circulating immune complexes was negative, and antibodies against M-type phospholipase A 2 receptor could not be detected. Western blot analyses identified circulating IgG3 reacting with superoxide dismutase 2. This case suggests that membranous nephropathy represents an additional renal manifestation of IgG4-related systemic disease, with a pathogenesis possibly associated with neoproduction of autoantibodies targeting podocyte antigen(s). Am J Kidney Dis. 58 :272-275.
American Journal of Kidney Diseases, 2013
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Journal of Babol University of Medical Sciences, 2017
BACKGROUND AND OBJECTIVE: Nowadays, anti-phospholipase A2 receptor (PLA2R) antibody is recognized as a diagnostic biomarker for idiopathic membranous nephropathy (iMN) and is also used to assess disease progression. Considering the differences in the prevalence of this antibody in various geographic regions, this study aims to evaluate the level of anti-PLA2R antibody in different types of glomerulonephritis and its relationship with proteinuria and creatinine clearance. METHODS: This cross-sectional study was conducted among 115 patients with diagnosis of glomerulonephritis and nephrotic syndrome. The patients were divided into three categories of iMN (34 patients), secondary membranous nephropathy (9 patients) and other types of glomerulonephritis (72 patients) based on their clinical history and test results. Demographic data, latest creatinine level, volume, protein and the 24-hour urine creatinine were recorded and the creatinine clearance was calculated. The serum level of anti-PLA2R antibody was measured and the level of antibody ≥ 20 RU/ml was considered positive. The level of antibody was compared between the three groups and the relationship between antibody levels and creatinine clearance and proteinuria was assessed in patients with iMN. FINDINGS: The mean age of the patients was 38±13 years. 81 patients (70%) were female. The mean (SD) antibody level in iMN patients was significantly higher than secondary membranous nephropathy and other types of glomerulopathy (129.9±190.1, 2.6±1.7, 2.0±1.6, respectively, P<0.0001). The antibody level was positive in 47% of the patients with iMN, while it was not positive in any of the other types of glomerulopathy (P<0.001). However, there was no significant relationship between antibody levels and creatinine clearance or 24-hour proteinuria in patients with iMN. CONCLUSION: Results of the present study demonstrated that the presence of anti-PLA2R antibody specifically indicates idiopathic membranous glomerulonephritis. However, antibody level is not associated with disease severity.
Case Reports in Nephrology, 2017
IgA nephropathy is the most frequent cause of primary glomerulonephritis, portends erratic patterns of clinical presentation, and lacks specific treatment. In general, it slowly progresses to end-stage renal disease. The clinical course and the response to therapy are usually assessed with proteinuria and serum creatinine. Validated biomarkers have not been identified yet. In this report, we present a case of acute renal injury with proteinuria and microscopic hematuria in a young male. A kidney biopsy disclosed IgA nephropathy. Podocyturia was significantly elevated compared to normal subjects. Proteinuria, renal function, and podocyturia improved promptly after steroids and these variables remained normal after one year of follow-up, when steroids had already been discontinued and patient continued on valsartan and amiloride. Our report demonstrates that podocyturia is critically elevated during an acute episode of IgA nephropathy, and its occurrence may explain the grim long-term...
Journal of Clinical & Experimental Nephrology, 2016
Objectives: To assess the prognostic value of IgG4 reactivity in biopsy-proven cases of idiopathic membranous nephropathy (iMN) and to outline its potential in guiding therapy. Methods: A retrospective study of biopsy-proven iMN cases from January 1997 to August 2013 was undertaken. Patients were identified, and an extensive analysis of the clinical and histological parameters were performed. The primary endpoint was a worse renal outcome, which was defined as doubling of the serum creatinine baseline value. Results: The study included 52 patients, with mean age of 38.0 years. The median baseline creatinine was 112.7 ± 36.3 umol/l among those with positive staining for IgG4 and 67.4 ± 19.3 umol/l among those with negative staining for IgG4 (P=0.5). There was no significant difference in the 24 hr urine protein between IgG4 positive and IgG4 negative staining cases (P=0.375). The probability of doubling serum creatinine was similar among those with or without IgG4 deposition. Follow up of the patients revealed that 23.4% of those with positive IgG4 and 14% of those with negative IgG4 had deterioration of the renal function. The prevalence and severity of tubulo-interstitial inflammation was not statistically different between the two groups. Conclusion: There was no relationship between IgG4 positivity and the severity of clinical and/or histological parameters in patients with iMN. IgG4 reactivity had no impact on the long-term outcome of the patients. Further studies are needed to outline the potential use of targeted therapy against IgG4 auto-antibody in a certain category of patients with membranous nephropathy.
American Journal of Kidney Diseases, 2020
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American Journal of Kidney Diseases, 2001
In idiopathic membranous nephropathy(MN), the main predictors for progression to chronic renal failure ( CRF) are the amount of proteinuria and the extent of tubulointerstitial damage. The aim of this study is to evaluate whether urinary excretion of proteins reflecting the alteration of permselectivity in the glomerular capillary wall, such as immunoglobulin G(IgG), and the reabsorption impairment of low-molecular-weight proteins, such as α 1-microglobulin (α 1 m) correlates with the extent of tubulointerstitial damage and have a predictive value for functional outcome and response to therapy better than 24-hour proteinuria. In 78 patients with MN, urinary excretion of albumin, transferrin, IgG, and a 1 m was measured by immunonephelometry in second-morning urine samples and expressed in milligrams per gram of urinary creatinine (uCr). In 48 patients with characterization of proteinuria and renal biopsy performed at the same time, excretion of IgG (P=0.0087) and α 1 m (P=0.0024) but not albumin (P=0.37), transferrin (P=0.38), or 24-hour proteinuria (P=0.32), was associated significantly with the global glomerular sclerosis (P=0.0032) and arteriolar hyalinosis (P=0.0004). Moreover, urinary excretion of α 1 m was significantly dependent on IgG excretion (r=0.67;P=0.0001) but not on albumin (P=0.66) or 24hour proteinuria (P=0.07). Functional outcome could be evaluated in 38 patients with nephrotic syndrome and baseline normal renal function (serum creatinine,0.99±0.20 mg/dL; follow-up, 44±22 months ). Remission was 100% versus 20% in patients with IgG excretion less than 110 mg/g uCr versus 110 mg/g uCr or greater (P=0.0001) and 77% versus 17% in patients with α 1 m excretion less than 33.5 mg/g uCr versus 33.5 mg/g uCr or greater (P=0.0009) respectively. In patients with IgG and α 1 m excretion less than or greater than the cutoff value, progression to CRF was 0% versus 35% (P=0.0026) and 0% versus 58% (P=0.0001) respectively. Nineteen patients treated with immunosuppressive therapy were compared with 19 untreated patients. There was no difference in remission or progression between treated and untreated patients when IgG and α 1 m excretion were less than the cutoff value. There was a significant difference for progression to CRF between treated and untreated patients when α 1 m excretion was greater than the cutoff value(17%