Clinicopathological characteristics and outcomes of PLA2R related idiopathic membranous nephropathy in patients with seronegative PLA2R antibodies

Abstract

Background

Idiopathic membranous nephropathy (IMN) with deposits of phospholipase A2 receptor (PLA2R) antigen in glomerular tissue (GAg+) but no circulating serum PLA2R antibody (SAb−) has been reported. However, little is known about the clinicopathological characteristics and prognosis of this subtype.

Methods

A total of 74 IMN patients with GAg + identified by kidney biopsy were enrolled in this study. We categorized patients into two groups based on the presence or absence of serum PLA2R antibody. Data on clinical features, pathological features, and outcomes were collected. Kaplan–Meier analysis of complete remission (CR) and partial remission (PR) comparing SAb−/GAg + and SAb+/GAg + patients. Cox proportional hazards models was used to examine factors associated with CR and PR.

Results

Among 74 IMN patients, 14 were SAb−/GAg+. Compared with SAb+/GAg + patients, SAb−/GAg + patients presented with higher levels of albumin, lower levels of cholesterol and low density lipoprotein cholesterol (all p < .01), but similar pathological manifestations of kidney biopsy. Multivariate logistic analyses indicated that low albumin (0.79 [95%CI: 0.66–0.95], p = .01) and high cholesterol (1.81 [95%CI: 1.02–3.19], p = .04) were correlated with seropositivity of PLA2R antibody. SAb−/GAg + patients exhibited a significantly higher probability of CR (p = .03) than patients who were SAb+/GAg+. However, no difference was found in the PR rate. Cox regression analyses showed that compared to SAb+/GAg + patients, SAb−/GAg + was more predictive of complete remission (4.28 [95%CI: 1.01–18.17], p = .04).

Conclusion

IMN with PLA2R staining on kidney biopsy but without serum PLA2R antibody has milder clinical manifestations and a better prognosis.

Keywords:

• Phospholipase A2 receptor
• membranous nephropathy
• proteinuria

Acknowledgements

We would like to thank all patients and their families for participating in this study.

Authors contributions

XL conceived and designed the study, performed the data collection, data analysis and manuscript writing. QMS were involved in the design of the study and led the study. YS, YCL and LJM performed the recruitment and data collection. All authors contributed to this article, and all have approved the final manuscript.

Ethics approval

This study was approved by the ethics committees of Beijing Chaoyang Hospital, Capital Medical University, Beijing China (approval notice number 2023-KE-419). The Institutional Review Board waived the requirement of informed consent due to the retrospective design of the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets of the current study are available from the corresponding author on reasonable request.

Additional information

Funding

No funding.