Anti-streptococcal cell membrane and anti-human glomerular basement membrane titers in sera of patients with poststreptococcal acute glomerulonephritis and anaphylactoid purpura.

To clarify the immunological mechanisms in poststreptococcal acute glomeulonephritis (PSAGN) and anaphylactoid purpura (AP), anti-streptococcal cell membrane (anti-SCM) and anti-human glomerular basement membrane (anti-GBM) titers in the sera of patients with PSAGN and AP were determined by passive hemagglutination with chromic chloride-treated sheep erythrocytes. Sodium lauryl sulfate (SLS) soluble SCM and collagenase soluble GBM were used as soluble antigens. Positive anti-SCM titers (greater than 1:8) were demonstrated in 10 of 14 patients (71.4%) with PSAGN and in 4 of 9 patients (44.4%) with AP with evidence of antecedent streptococcal infection. Two of 4 patients with AP without evidence of antecedent streptococcal infection had positive anti-SCM titers. No correlation was noted between anti-streptolysin O (ASO) titers and anti-SCM titers in patients with PSAGN or AP, but many patients with high ASO titers also had high anti-SCM titers. No positive anti-GBM reactions were detected in patients with PSAGN or AP. No cross-reactions were noted between SLS soluble SCM and collagenase soluble GBM.