American Board of Internal Medicine (ABIM) Certification Practice Exam

What type of lesions may occasionally be associated with IgG4-related interstitial nephritis?

1. Glomerulosclerosis

2. Membranous and membranoproliferative glomerulonephritis

3. Focal segmental glomerulosclerosis

4. Minimal change disease

The correct answer is: Membranous and membranoproliferative glomerulonephritis

IgG4-related interstitial nephritis is a part of a broader spectrum of IgG4-related disease, which is characterized by the infiltration of IgG4-positive plasma cells and lymphocytes into various tissues, leading to inflammation and fibrosis. While the interstitial nephritis itself is the primary renal manifestation, it can indeed be associated with specific types of lesions, particularly membranous and membranoproliferative glomerulonephritis. Membranous nephropathy and membranoproliferative glomerulonephritis have been noted to occur in patients with IgG4-related disease due to the immune-mediated mechanisms at play. In these cases, the presence of IgG4 antibodies and the resultant inflammation can lead to structural changes within the glomeruli, creating the characteristic lesions associated with these conditions. Other renal lesions such as glomerulosclerosis, focal segmental glomerulosclerosis, and minimal change disease are not typically associated with IgG4-related interstitial nephritis. While these conditions can arise in various contexts, they do not have the same direct connection to the IgG4-related inflammatory process that links to membranous and membranoproliferative glomerulonephritis. Thus, identifying