Membranous nephropathy associated with viral infection

Area of Science:

• Nephrology
• Virology
• Immunology

Background:

• Membranous nephropathy (MN) is linked to hepatitis B (HBV) and C (HCV) infections, and less frequently to human immunodeficiency virus (HIV).
• The role of anti-phospholipase A2 receptor (anti-PLA2R) and anti-thrombospondin type 1 domain-containing 7A (anti-THSD7A) antibodies in virus-associated MN is not well understood.

Purpose of the Study:

• To investigate the clinical, histopathological, and outcome data of patients with MN associated with HBV, HCV, or HIV infection.
• To determine the association of anti-PLA2R and anti-THSD7A antibodies in these patients.

Main Methods:

• Retrospective analysis of 19 patients with MN and viral infections (HBV, HCV, HIV) from a renal biopsy database.
• Assessment of kidney biopsy staining for PLA2R and THSD7A, and detection of circulating anti-PLA2R antibodies.

Main Results:

• The cohort included 19 patients (median age 42 years) with HBV (6), HCV (4), and HIV (9) infections; two HIV patients had HBV co-infection, and one had HCV co-infection.
• Anti-PLA2R antibodies were detected in 7/10 patients with positive PLA2R staining, including those with HBV-MN, HCV-MN, and HIV-MN.
• Anti-THSD7A antibodies were found in 3 PLA2R-negative cases, including one HBV-MN and two HIV-MN cases. Proteinuria was higher in PLA2R-positive patients.
• Remission occurred in 6/19 patients spontaneously and in 7/11 patients after treatment. Renal function was preserved in most patients.

Conclusions:

• This study describes a cohort of MN associated with viral infections, including rare instances of HIV-MN with PLA2R and THSD7A positivity.
• Further research is needed to elucidate the mechanisms underlying coincidental or virus-related MN.