Positive and negative hepatitis B virus in renal biopsies of IgA nephropathy: an 85-case clinicopathological analysis

SUMMARY: The aetiological role of hepatitis B virus (HBV) antigens in IgA nephropathy remains uncertain. In a clinicopathological study, we examined 85 patients with primary IgA nephropathy divided into two groups depending on whether renal biopsy specimens were positive or negative for HBV antigens (HBsAg, HBcAg and HBeAg) using immunohistochemical methods. Compared with patients in the negative group ( n = 59), those in the positive group ( n = 26) had more obvious gross haematuria, proteinuria, hypertension and renal impairment. Their haemoglobin level, serum IgA concentration and creatinine clearance were also significantly abnormal. Immunofluorescence microscopy indicated that immunoglobulins deposited were mainly found in the combination of IgA + IgG + IgM. Consistent with the clinical manifestations, the pathological lesions revealed more glomerular sclerosis, tubular epithelial degeneration and necrosis and interstitial inflammation and fibrosis ( P < 0.05). Thus, we concluded that the presence or absence of HBV in renal tissue from patients with IgA nephropathy results in significant differences in the clinical features, types and severity of pathological lesions and, consequently, prognosis. Tissue deposition of HBV might play an aetiological role in the pathogenesis of IgA nephropathy and may be an exacerbating factor in renal progressive deterioration. Antiviral therapy could be an important intervention in HBV antigen-positive patients.