Kidney Week

Abstract: PO1475

Can the Use of the Serum Anti-PLA2R Antibody Negate the Need for a Renal Biopsy in Primary Membranous Nephropathy?

Session Information

• Glomerular Diseases: Immunology and Inflammation in IgANP, C3GP, TMA, and Nephrotic Diseases
  November 04, 2021 | Location: On-Demand, Virtual Only
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1202 Glomerular Diseases: Immunology and Inflammation

Authors

• Ragy, Omar Sherin, Manchester Metropolitan University, Manchester, Greater Manchester, United Kingdom

Omar Sherin Ragy, MBChB

• Rautemaa, Vilma, Manchester Metropolitan University, Manchester, Greater Manchester, United Kingdom

Vilma Rautemaa,

• Kanigicherla, Durga Anil K, Manchester Metropolitan University, Manchester, Greater Manchester, United Kingdom

Durga Anil K Kanigicherla,

• Hamilton, Patrick, Manchester Metropolitan University, Manchester, Greater Manchester, United Kingdom

Patrick Hamilton,

Background

Since the emergence of the anti-PLA₂R antibody test, nephrology practice has not changed dramatically, and most nephrologists are still relying on performing a kidney biopsy in diagnosing membranous nephropathy. In this study, we sought to examine how anti-PLA₂R antibody tests using ELISA can be utilized in clinical practice.

Methods

We have conducted a retrospective analysis for 187 patients between 2003 and 2020 correlating their renal biopsy findings with their anti-PLA₂R antibody test when performed. We have recorded all patient’s demography, urine protein creatinine ratios, serum albumin, and treatment commenced whether using RAS blockade or immunosuppression treatment.
Using a statistical analysis model, we have calculated the positive and negative predictive values of the anti-PLA₂R ab test carried out during that period.

Results

The mean levels of anti-PLA2R antibody titer in primary membranous nephropathy were 217 RU/ml, whereas the mean level was only 3 RU/ml for both secondary membranous nephropathy and other diagnoses. The majority of our cohort who had a positive anti-PLA₂R antibody test had a confirmed renal biopsy diagnosis of primary membranous nephropathy with a PPV of 97.3%. Also, we found that the test sensitivity was 75.5%. On the other hand, we found that the NPV was 79.8% and the specificity was 97.8% at a level of >20 RU/ml

Conclusion

The anti-PLA₂R antibody test is a highly specific test for diagnosing membranous nephropathy. Experience from our center supported by some evidence from the literature suggests that we can rely solely on a positive test without the need to perform a renal biopsy. More prospective trials are required to further validate that notion.

Funding

• Private Foundation Support