Anti‐M in Children with Acute Bacterial Infections

Abstract
Four children, 7-24 mo. old, had anti-M antibodies at the time of admission to the hospital for severe acute bacterial [Haemophilus influenzae, Proteus mirabilis, Staphylococcus aureus, Neisseria meningitidis] infections. All were M-negative, N-positive. Two patients had meningitis, 1 had septic arthritis and the 4th had a 3rd-degree burn of the left hand. In follow-up studies, the anti-M of patients no. 3 and no. 4 were no longer detectable after 12 and 11 mo., respectively. In all patients no demonstrable antibody was in maternal or cord sera at time of birth. Bacterial infections may account for the formation of naturally occurring anti-M in M-negative persons.