Prognostic Value of Baseline Serum Lactate Dehydrogenase Level in Patients With Hairy Cell Leukemia

Background: Hairy cell leukemia is a rare B-cell lymphoproliferative disorder. It has an indolent course with relapse and remission periods. The aim of this study was to investigate the clinical characteristics and risk factors affecting the outcome of patients with hairy cell leukemia.

Patients and methods: The retrospective data of 65 patients were evaluated according to initial hematologic and biochemical parameters, response rates, progression-free survival, and overall survival. Factors effecting response and survival rates were analyzed.

Results: The median follow-up duration was 62.8 months (range, 5.7-229.3 months). The result of the analysis showed that the patients with relapse/progressive disease had higher lactate dehydrogenase (LDH) levels at the time of diagnosis than patients without relapse/progression (median [range], 243 [137-540] vs. 179 [99-334] U/L, P = .01). Patients with LDH ≥ 200.5 IU at the time of diagnosis were demonstrated to have a shorter progression-free survival than those with LDH < 200.5 IU (P = .010).

Conclusion: Serum LDH level is significantly associated with relapse/progression in hairy cell leukemia patients. Patients with higher LDH levels at diagnosis should be monitored closely even if they experience complete remission.