American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the autoantibody linked to membranous nephropathy?

1. Anti-Jo-1

2. Anti-phospholipase A2 receptor

3. Anti-SRP

4. Anti-centromere

The correct answer is: Anti-phospholipase A2 receptor

The autoantibody linked to membranous nephropathy is anti-phospholipase A2 receptor. This condition is characterized by the presence of these antibodies in a significant number of patients, which plays a crucial role in the pathogenesis of the disease. Membranous nephropathy is primarily associated with immune complex deposition along the glomerular capillary wall, leading to significant damage and resultant nephron impairment. The anti-phospholipase A2 receptor autoantibodies target the phospholipase A2 receptor on podocytes, which are specialized cells in the kidney that help maintain the integrity of the glomerular filtration barrier. Recognizing the significance of this autoantibody helps in the diagnosis and management of membranous nephropathy, guiding clinicians toward the appropriate immunomodulatory therapies. The presence of these antibodies can also differentiate primary membranous nephropathy from secondary causes, aiding in treatment decisions. Other autoantibodies listed are associated with different autoimmune conditions but do not have a direct link to membranous nephropathy, highlighting the importance of understanding specific autoantibody roles in various renal pathologies.