Hereditary adenosine deaminase deficiency results in failure of the lymphocyte development. This occurs because of the accumulation of deoxyadenine nucleotides in cells with high deoxycytidine kinase and low 5'-nucleotidase activity. 2-Chlorodeoxyadenosine (2-CdA) resists the action of adenosine deaminase and accumulates in cells with high deoxycytidine kinase and low 5'-nucleotidase activity. It is equally toxic to dividing and nondividing cells and may act by preventing repair of DNA single-strand breaks. In doses of 0.1 mg/kg/day given for seven days 2-CdA manifests low toxicity. It has been found to be effective in the treatment of patients with lymphoid neoplasms, including advanced cutaneous T-cell lymphomas, chronic lymphocytic leukemia, non-Hodgkin lymphomas, and hairy cell leukemia. In the latter disorder it appears to be as or more effective than the tight-binding adenosine deaminase inhibitor, deoxycoformycin, and is probably less toxic. 2-CdA also appears to be effective in controlling autoimmune hemolytic anemia and shows promise in the treatment of other autoimmune diseases.
Keywords: 2 chlorodeoxyadenosine; 2-CdA; hairy cell leukemia; lymphoid leukemias.