Infectious complications in 127 patients with hairy cell leukemia.

Information regarding infectious complications was obtained on 127 patients with hairy cell leukemia who were diagnosed between March 1974 and April 1982. Forty-seven patients (37%) had 111 documented infections (cultures positive), and 40 patients (31.5%) had 113 nondocumented infections (no culture results available, or cultures negative). The remaining 40 patients (31.5%) had no significant infections during the course of their disease. Patients without infection lived significantly longer than did patients who developed an infection (92% v 49% were alive at 4 years; P = .0012). Thirty-three of the 47 patients with documented infection have died; 29 of an infectious problem and four of a noninfectious problem. There was also a statistically significant difference in actuarial survivals between the documented-infection and nondocumented infection groups (P = .007). The two most common types of infection were bacteremia (30 episodes) and pneumonia (27 episodes). In the culture-documented group with bacteremia, E coli and P aeruginosa caused ten and eight infections, respectively, and three infections were due to S aureus. There were eight systemic infections of nonbacterial origin; in five, the organism cultured was M kansasii, and three were fungal infections. Blood counts at the time of diagnosis were not correlated with subsequent development of infection. Patients with hairy cell leukemia have a significant susceptibility to infections that can affect morbidity and mortality. Many of the infectious complications encountered are those common in patients whose immune system is compromised; however, the occurrence of disseminated atypical mycobacterial disease requires a heightened awareness.