HIV-associated Immune Complex Kidney Disease with C3-dominant Deposition Induced by HIV Infection after Treatment of IgA Nephropathy

Abstract

A 57-year-old man was diagnosed with IgA nephropathy. Hematuria and proteinuria were improved by tonsillectomy plus methylprednisolone pulse therapy. Lymphadenopathy, hypocomplementemia and pancytopenia were observed six years later, and urinalysis abnormalities recurred. A biopsy revealed mesangial proliferative glomerulonephritis with C3-dominant deposition. Human immunodeficiency virus (HIV) antibody demonstrated positive conversion. He was diagnosed with HIV-associated immune complex kidney disease (HIVICK). The hematuria, proteinuria and hypocomplementemia were improved by reducing the HIV viral load through antiretroviral therapy. When C3-dominant deposition is observed on a renal biopsy, HIVICK must be differentiated.

Keywords: complement activation; human immunodeficiency virus; renal biopsy.

Figure 1.

The findings of the first renal biopsy specimens. (A) Light microscopic findings by Periodic acid-Schiff (PAS) staining (original magnification ×400). (B-F) Immunofluorescence (IF) study of (B) IgG, (C) IgA, (D) IgM, (E) C3 and (F) C1q. IF studies showed strong staining of IgA, moderate staining of C3 and weak staining of IgG and IgM in the mesangial areas.

Figure 2.

The findings of the second renal biopsy specimens. (A) Light microscopic findings by PAS staining (original magnification ×400). (B-G) IF study of (B) IgG, (C) IgA, (D) IgM, (E) C3, (F) C1q and (G) C4d. IF studies showed strong staining of C3; weak staining of IgM, C1q and C4d; and faint staining of IgG and IgA in the mesangial areas. (H) Electron microscopic findings. Small electron-dense deposits were noted mainly in the mesangial area (white arrowhead) and scantly in the subepithelial (black arrowhead) and subendothelial (arrow) areas (original magnification ×3,000).

Figure 3.

The clinical course from the first biopsy to ART therapy. Following therapy for IgAN, the patient’s hematuria was negative, and his proteinuria had decreased. Roughly seven years later, he developed hematuria and proteinuria and was diagnosed with HIVICK. The urinary findings were improved by combination ART.