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

Routine immunologic screening of four patients with chronic mucocutaneous candi­ diasis (CMC) revealed that they manifested positive Schick tests in ·ui;,o despite adequate diphtheria toxoid immunization and the presence of circulating hemaggluti­ nating antibody to diphtheria. Plasma from these individuals was found to neutralize Schick toxin in rabbits. Unlike normal individuals who preferentially make IgG neutral­ izing antibody to diphtheria toxin when immunized, these patients with CMC have neutralizing activity in plasma fractions containing Ig11. Ig1I is predominantly an intravascular protein which would account for the failure of our patients to neutralize Schick toxin in i•ivo. These findings suggest that T cell deficiency as it occurs in CMC may lead to B cell dysfunction in man.