Prevalence of HTLV-I Antibody in Pulmonary Cryptococcosis

A retrospective study was done to determine the prevalence of anti-HTLV-I antibodies in patients with pulmonary cryptococcosis. None of the 19 patients with pulmonary cryptococcosis had underlying immunodeficiency. Anti-HTLV-I antibody was present in 6 (32%) of 19 patients with pulmonary cryptococcosis, a significantly higher prevalence than found in patients with bronchial asthma (4 (7%) of 58) (p<0.01, chi-square test). No statistical difference was noted when anti-HTLV-I antibody seropositivity was compared to that of patients with pulmonary tuberculosis (16% (17/105)), lung cancer (17% (22/129)) and pneumonia (9% (6/64)). A reduced cellular immunity as shown by lymphopenia, the CD4/CD8 ratio and purified protein derivative skin test was found in only 1 (5%) of 19, 2 (12%) of 17, and 6 (33%) of 18 patients, respectively. These results do not explain the susceptibility to pulmonary cryptococcosis in HTLV-I carriers. This is the first report of high prevalence of pulmonary cryptococcosis in HTLV-I carriers and it raises the question whether HTLV-I carriers are more susceptible to opportunistic infections and other malignancies probably due to subtle immunological abnormalities.