TRANSITORY DEPRESSION OF IMMUNE FUNCTION FOLLOWING MYCOPLASMA-PNEUMONIAE INFECTION IN CHILDREN

Abstract

A broad array of immunological tests was performed in children with serologically confirmed M. pneumoniae infection. In a group of 21 children studied 0-6 wk after onset of illness, neutrophil chemotaxis was 1.46 .+-. 0.43 mm/3 h (mean .+-. SD) in patients compared to 1.79 .+-. 0.28 mm/3 h in controls (P < 0.05). In a subgroup of 7 children studied 0-2 wk after onset of illness, the [3H]thymidine uptake (mean .+-. SE) was 12,786 .+-. 2635 cpm in patients compared to 26,454 .+-. 3345 in controls for phytohemagglutinin (P < 0.02) and 5321 .+-. 535 in patients compared to 16,086 .+-. 3596 in controls for pokeweed mitogen (P < 0.02). There was no impairment in response to soluble concanavalin A: 18,715 .+-. 1446 in patients compared to 25,193 .+-. 2564 in controls (P > 0.1). Follow-up studies on 5 of these 7 children showed that lymphocyte proliferative responses to phytohemagglutinin and pokeweed mitogen of all 5 children returned to normal values some weeks later. In another group of 28 children studied 13-18 wk after onset of illness, 4 had subnormal IgG values. Of the 3 children available for follow-up studies, all had normal values for serum IgG 2-5 mo. later. The transitory depression of immune function following M. pneumoniae infection observed in these studies may explain some of the clinical features of the disease, such as the persistence of M. pneumoniae for long periods in the respiratory tract, the high incidence of intercurrent infection and the high incidence of autoimmune manifestations.