Chronic mucocutaneous candidiasis: T cell deficiency associated with B cell dysfunction in man

Routine immunologic screening of four patients with chronic mucocutaneous candidiasis (CMC) revealed that they manifested positive Schick tests in vivo despite adequate diphtheria toxoid immunization and the presence of circulating hemagglutinating antibody to diphtheria. Plasma from these individuals was found to neutralize Schick toxin in rabbits. Unlike normal individuals who preferentially make IgG neutralizing antibody to diphtheria toxin when immunized, these patients with CMC have neutralizing activity in plasma fractions containing IgM. IgM is predominantly an intravascular protein which would account for the failure of our patients to neutralize Schick toxin in vivo. These findings suggest that T cell deficiency as it occurs in CMC may lead to B cell dysfunction in man.