Serum Anti-PLA2R Antibody Predicts Treatment Outcome in Idiopathic Membranous Nephropathy

2016 ◽  
Vol 43 (2) ◽  
pp. 129-140 ◽  
Author(s):  
Shi-Yao Wei ◽  
Yu-Xiao Wang ◽  
Jian-Si Li ◽  
Shi-Lei Zhao ◽  
Tian-Tian Diao ◽  
...  

Background: M-type phospholipase A2 receptor (PLA2R) has been identified as the major target antigen in idiopathic membranous nephropathy (IMN). However, the role of glomerular PLA2R (gPLA2R) and the associations of serum anti-PLA2R antibody (sPLA2R-Ab) titre with diagnosis, treatment and prognosis in IMN need to be further investigated. Methods: We screened 148 consecutive patients with biopsy-proven membranous nephropathy (MN; 113 with IMN and 35 with secondary MN (SMN)) who were followed up for ≤20 months. Serum and urine samples were simultaneously collected at different time points. The levels of sPLA2R-Ab were detected using immunofluorescence and enzyme-linked immunosorbent assay. gPLA2R was assessed by immunofluorescence. Results: Most patients with IMN displayed both gPLA2R and sPLA2R-Ab positive (85.8 and 82.3%, respectively). In contrast, very few patients with SMN showed either gPLA2R or sPLA2R-Ab positive. The sPLA2R-Ab titre, not gPLA2R, was significantly correlated with proteinuria. Surprisingly, changes in sPLA2R-Ab titre occurred earlier and faster than proteinuria in patients who were followed up for ≤20 months during the whole period of observation. Survival analysis of IMN patients indicated a significant association between sPLA2R-Ab titre and outcome, whereas, no significant difference was observed between the gPLA2R intensity and outcome. Conclusions: These data indicate that sPLA2R-Ab might be a better biomarker for IMN diagnosis and treatment outcome. In addition, monitoring sPLA2R-Ab titre may assist in determining when to initiate the administration of immunosuppressive agents and in evaluating treatment efficacy.

2019 ◽  
Vol 12 (1) ◽  
pp. 27-32
Author(s):  
Yosuke Inaguma ◽  
Atsutoshi Shiratori ◽  
Taku Nakagawa ◽  
Kyoko Kanda ◽  
Makiko Yoshida ◽  
...  

Background: Membranous Nephropathy (MN) is a common cause of nephrotic syndrome in adults that can also occur in children, albeit less frequently. Recently, the M-type phospholipase A2 receptor (PLA2R) was identified as the target antigen in idiopathic membranous nephropathy (IMN), making it a useful marker for diagnosis. However, there are few studies describing the potential role of PLA2R in children with IMN. The aim of this study was to clarify the involvement of PLA2R in childhood IMN. Methods: We enrolled 11 patients diagnosed with IMN from January 1998 to March 2017. We performed PLA2R staining in paraffin-embedded renal biopsy sections. The clinical data were collected from the patients’ medical records. Results: The median age at biopsy was 6 years (range, 4 to 14 years). A single 6-year-old boy among all pediatric patients with IMN had granular PLA2R staining along his glomerular capillary loops and the prevalence of PLA2R-positivity was 9%. He also showed IgG4 co-dominant staining in terms of IgG subclass. There were no apparent differences in his clinical features such as clinical data at the time of renal biopsy, the time from the treatment initiation to remission, and relapse or renal dysfunction during the follow-up period. Conclusion: We suggest that PLA2R staining can be a diagnostic tool for patients with IMN of any age, though pediatric patients with IMN have lower prevalence of PLA2R-positive staining than adult patients.


2019 ◽  
Vol 34 (4) ◽  
pp. 406-413
Author(s):  
Dan Zhang ◽  
Chong Zhang ◽  
Fan Bian ◽  
Wenzhu Zhang ◽  
Gengru Jiang ◽  
...  

Background: Membranous nephropathy is the most common glomerular disease related to malignancy. However, it is difficult to distinguish between true malignancy-related membranous nephropathy and idiopathic membranous nephropathy coincident with cancer. It has been reported that phospholipase A2 receptor (PLA2R) is the first autoantigen involved in idiopathic membranous nephropathy and thrombospondin type-1 domain-containing 7A (THSD7A) may have a close relationship with malignancy-related membranous nephropathy. Therefore, the aim of this study was to compare the clinicopathological characteristics between membranous nephropathy patients with cancer and idiopathic membranous nephropathy patients without cancer to better detect malignancy-related membranous nephropathy, including glomerular PLA2R and THSD7A depositions and their circulating antibodies, together with glomerular IgG4 deposition. Methods: Twelve membranous nephropathy patients with cancer and 257 idiopathic membranous nephropathy patients without cancer were included in this study and had been followed up for more than 1 year. The glomerular expression of PLA2R, THSD7A, and IgG4 was analyzed by immunohistochemistry. Circulating anti-PLA2R and anti-THSD7A antibodies were assessed by enzyme-linked immunosorbent assay and indirect immunofluorescence testing, respectively. Results: Membranous nephropathy patients with cancer were significantly older and had higher serum creatinine and a lower estimated glomerular filtration rate than idiopathic membranous nephropathy patients ( P<0.05). The positive rates of glomerular PLA2R and IgG4 depositions and circulating anti-PLA2R antibodies in membranous nephropathy patients with cancer were significantly lower than those in idiopathic membranous nephropathy patients without cancer ( P<0.01). Conclusion: The absence of glomerular PLA2R deposition and negative circulating anti-PLA2R antibodies, along with negative glomerular IgG4 staining, may be useful clues to more accurately screen underlying malignancies in membranous nephropathy patients.


2015 ◽  
Vol 42 (3) ◽  
pp. 250-257 ◽  
Author(s):  
Yang Gyun Kim ◽  
Young-Wook Choi ◽  
Se-Yun Kim ◽  
Ju Young Moon ◽  
Chun-Gyoo Ihm ◽  
...  

Background: Anti-phospholipase A2 receptor antibody (PLA2R-Ab) is useful in diagnosing idiopathic membranous nephropathy (IMN). We investigated the clinical relevance of PLA2R-Ab enzyme-linked immunosorbent assay (ELISA) in patients with IMN. Methods: We measured PLA2R-Ab with an ELISA kit from the serum of 160 patients with IMN (n = 93), secondary MN (n = 14) and other glomerulonephritis (n = 41) as well as healthy controls (n = 12) at the time of renal biopsy and investigated the correlation of titers of PLA2R-Ab with clinical parameters. Results: PLA2R-Ab was positive in 41 of 93 patients (44.1%) with IMN. No samples from the patients with secondary MN and other glomerulonephritis or healthy controls were positive with the ELISA test. The PLA2R-Ab-positive patients showed severe disease activity and a low remission rate. The PLA2R-Ab titer positively correlated with proteinuria and was negatively associated with renal function and serum albumin. The patients with a high titer of PLA2R-Ab had significantly decreased remission rates. The cumulative probabilities of remission was significantly lower in patients with PLA2R-Ab (p = 0.01) and even so in patients with a high titer of PLA2R-Ab (p = 0.04). When we compared the ELISA titers with Western blot (WB) data of 43 patients who had been enrolled in our previous study, 18 and 30 patients were positive on ELISA (41.9%) and WB (69.8%), respectively. WB and ELISA had a concordance rate of 72.1% and were positively correlated (r = 0.590, p < 0.001). Conclusion: The presence, as well as a high titer, of PLA2R-Ab on ELISA was associated with poor prognosis of IMN. Assessment of PLA2R-Ab with ELISA is an easy and reliable tool for the diagnosis and guidance of therapeutic plans.


Author(s):  
Brunetta Porcelli ◽  
Andrea Guarnieri ◽  
Fabio Ferretti ◽  
Guido Garosi ◽  
Lucia Terzuoli ◽  
...  

Abstract Background Autoantibodies against-phospholipase A2 receptor (PLA2R) are specific markers of idiopathic membranous nephropathy (iMN). Enzyme-linked immunosorbent assay (ELISA) is becoming the preferred method in many laboratories for the determination of anti-PLA2R antibodies, because it provides quantitative results, and is not prone to subjective interpretation, as is the case with indirect immunofluorescence assay. Methods The purpose of our study was to determine the diagnostic performance of serum PLA2R antibodies detected by commercially available ELISA in a large Italian multicenter cohort of patients with biopsy-proven iMN and in patients with other renal diseases, with special focus on evaluating the optimal cut-off value to discriminate positive and negative results. A total of 495 consecutive patients were recruited. Renal biopsies were performed in all patients, and blood samples were taken before the initiation of immunosuppressive treatment. Results According to the clinical diagnosis and to kidney biopsy, 126 patients were diagnosed with iMN and 369 had other non-membranous nephropathies. Anti-PLA2R autoantibodies were detected using a commercial anti-PLA2R ELISA. At a cut-off value of 20 relative units (RU)/ml indicated by the manufacturer for positive classification, sensitivity was 61.1% and specificity 99.7%. At a cut-off value of 14 RU/ml indicated by the manufacturer for borderline results, sensitivity was 63.5% and specificity remained the same (99.7%). At a cut-off of 2.7 RU/ml, selected as the optimal cut-off on the basis of ROC curve analysis, sensitivity was 83.3% and specificity 95.1%. The best overall efficiency of the test was observed at 2.7 RU/ml; however, the highest positive likelihood ratio and diagnostic odds ratio were achieved at 14 RU/ml. A cut-off threshold higher than 14 RU/ml or lower than 2.7 RU/ml entailed worse test performance. Conclusion Depending on the clinical use (early diagnosis or as a support to confirm clinical diagnosis), nephrologists may take advantage of this evidence by choosing the most convenient cut-off. However, renal biopsy remains mandatory for the definitive diagnosis of iMN and for the assessment of disease severity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tiffany N. Caza ◽  
Laith F. Al-Rabadi ◽  
Laurence H. Beck

The identification of the major target antigen phospholipase A2 receptor (PLA2R) in the majority of primary (idiopathic) cases of membranous nephropathy (MN) has been followed by the rapid identification of numerous minor antigens that appear to define phenotypically distinct forms of disease. This article serves to review all the known antigens that have been shown to localize to subepithelial deposits in MN, as well as the distinctive characteristics associated with each subtype of MN. We will also shed light on the novel proteomic approaches that have allowed identification of the most recent antigens. The paradigm of an antigen normally expressed on the podocyte cell surface leading to in-situ immune complex formation, complement activation, and subsequent podocyte injury will be discussed and challenged in light of the current repertoire of multiple MN antigens. Since disease phenotypes associated with each individual target antigens can often blur the distinction between primary and secondary disease, we encourage the use of antigen-based classification of membranous nephropathy.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Hao-yuan Cui ◽  
Chao Li ◽  
Hang Li ◽  
Yu-bing Wen ◽  
Lin Duan ◽  
...  

Background. The role of IgG subclass in idiopathic membranous nephropathy (IMN) was unclarified. Recent study found IgG subtype switches from IgG1 to IgG4 in the early pathological stage in IMN. The profile of IgG subclass in phospholipase A2 receptor- (PLA2R-) related and PLA2R-unrelated IMN was unrevealed. Our study is aimed at testifying whether IgG subclass switch existed in PLA2R-related and PLA2R-unrelated IMN, respectively. Methods. Our study retrospectively enrolled 157 Chinese patients with biopsy-confirmed IMN between September 2017 and November 2019. We measured glomerular PLA2R antigen and serum anti-PLA2R antibody to classify the patients into PLA2R-related ( n = 132 ) and PLA2R-unrelated ( n = 25 ) subgroup. We evaluated glomerular IgG subclass by immunofluorescence (IF) predominance. Our study defined IgG subclass deposition as predominant if the IF score was higher than the other three and ≥1 +, or as codominant if the IF intensity was equal to any other and ≥1 +. We explored the relationship between IF predominance of glomerular IgG subtype and electron microscopic (EM) stages of IMN. Results. We did not find statistical difference of predominant or codominant rate (pre/co-rate) among EM stages in any subclass ( P > 0.05 ). Pre/co-rate of IgG3 linearly associated with EM stage in total and PLA2R-related subgroup ( P = 0.044 , P = 0.013 ). PLA2R-related subgroup showed higher IgG4 intensity ( 2.1 ± 0.6 vs. 1.6 ± 0.7 , P = 0.001 ) and pre/co-rate of IgG4 in stage 1 (97% vs. 57%, P = 0.015 ) than PLA2R-unrelated group. We found no difference of IgG subclass pre/co-rate in different EM stages or linear association between pre/co-rate of IgG1, IgG2, IgG4, and EM stages ( P > 0.05 ). Conclusions. Pre/co-rate of IgG3 declined with EM stage in total and PLA2R-related subgroup. We did not find IgG subclass switches from IgG1 to IgG4 in either IMN patients or subgroups.


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