The mechanisms of bodily defense against fungal diseases remain largely unknown. Circulating antibodies are frequently demonstrable during infections with Histoplasma capsulatum and Candida albicans, for instance, but this may reflect activity of the infectious process rather than specific immunity.1 It has been suggested that cellular immunity plays an important role in killing and eliminating facultative intracellular bacterial pathogens, for exampe, BCG Brucella and Listeria monocytogenes as well as certain fungi. Thus far, data have been obtained largely from experimental animals. Nonetheless, observations of both animals and humans lacking cell-mediated immune functions indicate that deficiencies of the thymus-dependent immune system are associated with markedly enhanced susceptibility to fungus infection,2,3 infection with facultative intracellular bacteria pathogens, and even some viral agents.4 In this report, we present a patient with nonlymphopenic hypogammaglobulinemia (HGG) who appears to have had an adequate immunological defense against H capsulatum, despite a severe deficit in