M-KANSASII PULMONARY-DISEASE IN IDIOPATHIC CD4-LYMPHOCYTOPENIA( T)

Cases of patients with markedly depressed CD4+ T-lymphocyte counts, wi th or without opportunistic infections, in the absence of any evidence of human immunodeficiency virus (HIV) have been described in recent y ears. In 1992, the definition of ''idiopathic CD4+ T-lymphocytopenia'' was formulated by the Centers for Disease Control and Prevention (CDC ) of Atlanta (USA). The present case illustrates the occurrence of an unexplained Mycobacterium kansasii pneumonia in a white HIV-negative s ubject with a persistent depletion of CD4+ T-lymphocytes and suppressi on of cell-mediated immunity. To our knowledge, this is the first obse rvation of idiopathic CD4+ T-lymphocytopenia with pulmonary mycobacter iosis due to Mycobacterium kansasii, and the sixth case of this kind o f immunodeficiency described in Italy.