Transitory depression of immune function following Mycoplasma pneumoniae infection in children.

A broad array of immunological tests was performed in children with serologically confirmed Mycoplasma pneumoniae infection. In a group of 21 children studied 0 to 6 wk after onset of of illness, neutrophil chemotaxis was 1.46 +/- 0.43 mm/3 hr (mean +/- S.D.) in patients compared to 1.79 +/- 0.28 mm/3 hr in controls (P less than 0.05). In a subgroup of seven children studied 0 to 2 wk after onset of 2,635 cpm in patients compared to 26,454 +/- 3,345 in controls for phytohaemagglutinin (P less than 0.02) and 5,321 +/- 535 in patients less than 0.02). There was, however, no impairment in response to soluble concanavalin A: 18,715 +/- 1,446 in patients compared to 25,193 +/- 2,564 in controls (P greater than 0.1). Follow-up studies on five of these seven children showed that lymphocyte proliferative responses to phytohaemagglutinin and pokeweed mitogen of all five children returned to normal values some weeks later. In another group of 28 children studied 13 to 18 wk after onset of illness, four had subnormal IgG values. Of the three children available for followup studies, all had normal values for serum IgG 2 to 5 months later.