[Role of alpha-interferon in the treatment of hairy cell leukemia]

Hairy cell leukemia (HCL) is a chronic lymphoproliferative disorder that is characterized clinically by splenomegaly, pancytopenia, and the presence of malignant tartrate-resistant acid phosphatase (TRAP)-positive lymphocytes displaying unique morphological features in the peripheral blood and bone marrow. In the past, splenectomy has been the mainstay of treatment, resulting in symptomatic palliation and hematological improvement in 90 percent of patients. However, most patients undergoing splenectomy eventually require additional therapy; hematologic parameters and the degree of bone marrow cellularity are now utilized to identify to identify subsets of patients who might derive long-term benefit from the procedure. 2'-Deoxycoformycin (DCF) and 2-chlorodeoxyadenosine (2-cda) are experimental agents that have demonstrated curative potential in HCL; however, unresolved concerns about the long-term toxicity of DCF currently preclude its routine use, and further studies are required to define the toxicity and duration of responses obtained with 2-cda. As a result, alpha-interferon (alpha IFN) presently represents the treatment of choice for most patients with HCL. While alpha IFN has not been shown to cure HCL, its advantages include a high rate of response, a favorable side effect profile, its ability to be used safely in patients with active infections, and its ability to re-induce remission in relapsing patients. The mechanisms underlying alpha IFN's effectiveness seem to involve its immunomodulatory actions, which decrease the frequency of infectious complications in the early stages of therapy, and its ability to induce hairy cells to differentiate into more mature cells less responsive to proliferative signals.(ABSTRACT TRUNCATED AT 250 WORDS)