General immune reactivity in keloid patients.

Serum immunoglobulin levels (IgM, IgG, IgA), complement levels (C3 and C4), and the response of peripheral blood lymphocytes to mitogens [phytohemagglutinin (PHA), concanavalin A (Con-A), and pokeweed mitogen (PWM)] were investigated in healthy patients clinically diagnosed as keloid formers and in nonkeloid volunteers in good health. Serum IgM and serum C3 were significantly higher in keloid patients than in nonkeloid patients both at P less than 0.001, while serum IgA and serum C4 levels were higher in nonkeloid patients than in keloid patients at P less than 0.01 and P less than 0.001, respectively. Serum IgG levels were essentially unchanged in the keloid and the control groups in this study. Mitogenic stimulation was significantly lower in the keloid population in this investigation at P less than 0.001 for both PHA and Con-A. However, major differences were not observed with PWM stimulation in both keloid and control groups.