Circulating immune complex in glomerulonephropathy associated with hepatitis B virus infection

Area of Science:

• Pediatric Nephrology
• Hepatology
• Immunology

Background:

• Urinary abnormalities and positive Hepatitis B virus surface antigen (HBsAg) were observed in 9 pediatric patients.
• Many cases were identified through mass urine screening in school children, highlighting a public health surveillance opportunity.

Purpose of the Study:

• To investigate the association between Hepatitis B virus (HBV) infection and kidney disease in children.
• To characterize the renal pathology and immunological findings in HBsAg-positive children with urinary abnormalities.

Main Methods:

• Renal biopsy was performed to determine the specific type of glomerulonephropathy.
• Immunofluorescent studies were used to detect immune deposits in the glomeruli.
• Circulating immune complexes were assessed using C1q-binding and protein-A precipitation assays.

Main Results:

• Renal biopsy revealed 6 cases of membranous glomerulonephropathy (MGN) and 3 cases of minimal change disease.
• Immune deposits (HBeAg, IgG, C3) were found in the glomerular capillary walls of MGN patients.
• Circulating immune complexes were detected in 67% (C1q-binding) and 56% (protein-A) of patients with urinary abnormalities and hepatic dysfunction.

Conclusions:

• Hepatitis B virus infection is associated with significant renal pathology in children, particularly MGN.
• The presence of immune deposits in the glomeruli suggests an immune complex-mediated mechanism in HBV-related glomerulonephritis.
• Screening for HBsAg in children with urinary abnormalities is crucial for early diagnosis and management of kidney disease.