Anti-M in children with acute bacterial infections.

Four children, 7 to 24 months old, were found to have anti-M at the time of admission to the hospital for severe acute bacterial infections. All were M-N+. Two patients had meningitis, one had septic arthritis, and the fourth had a third-degree burn of the left hand. In follow-up studies the anti-M of patients No3 and No4 were no longer detectable after 12 and 11 months respectively. In all patients no demonstrable antibody was in either maternal or cord sera at time of birth. The clinical data and bacterial isolations lead us to postulate that bacterial infections account for the formation of naturally occurring anti-M in M-negative persons.