[Pneumocystis carinii pneumonia during therapy with 2-chlorodeoxyadenosine (2-CDA)].

We report the case of a 70-year-old patient with B-cell chronic lymphocytic leukemia. During therapy with the new purine analog 2-chloro-deoxyadenosine (2-CDA) the patient developed Pneumocystis carinii pneumonia (PCP). Although the mechanism of action of 2-CDA suggests the incidence of opportunistic infections and therefore pneumocystis pneumonia, this is the first case of PCP among 140 patients of the Swiss study of 2-CDA. The mechanism of action of 2-CDA is described and the occurrence of PCP among patients without acquired immunodeficiency syndrome is discussed.