Cationic antigens in poststreptococcal glomerulonephritis.

Area of Science:

• Nephrology
• Immunology
• Pathology

Background:

• Antigen charge influences experimental immune complex glomerulonephritis.
• Post-streptococcal glomerulonephritis (APSGN) is a kidney disease with a known causative agent.
• The role of antigen charge in human APSGN requires investigation.

Purpose of the Study:

• To investigate the role of antigen charge in human post-streptococcal glomerulonephritis.
• To determine if cationic streptococcal antigens are present in renal biopsies of APSGN patients.
• To explore the mechanism of immune complex formation in APSGN.

Main Methods:

• Analysis of renal biopsies from patients with acute post-streptococcal glomerulonephritis.
• Detection of extracellular streptococcal antigens using immunofluorescence.
• Serological testing for antibodies to cationic streptococcal antigens.

Main Results:

• Cationic, extracellular streptococcal antigens were detected in 8 out of 18 renal biopsies.
• Antigen presence correlated with earlier biopsies and co-deposition of IgG and IgM.
• Patients' sera contained antibodies against these cationic streptococcal antigens.

Conclusions:

• Cationic streptococcal antigens are present in a significant proportion of APSGN renal biopsies.
• These antigens may initiate APSGN through in situ immune complex formation.
• The charge of the antigen is a critical factor in the pathogenesis of APSGN.