Association of lymphopenia and eosinophilia with dimethylfumarate treatment efficacy and tolerability in psoriasis: a retrospective study.

Dimethylfumarate (DMF) is an effective treatment for psoriasis, which may cause side effects in a considerable group of patients. Alterations in white blood cell (WBC) counts may predict treatment success and the occurrence of side effects. To analyze WBC counts with respect to efficacy and the prevalence of side effects during DMF therapy for psoriasis. Psoriasis patients were treated with DMF. Retrospective data (WBC counts, treatment results, and side effects) were analyzed to assess correlations with respect to efficacy, tolerability, and leukocyte subsets. Of 95 patients treated with DMF, 60 patients (63.2%) had treatment success at week 16 and 77 patients (81.1%) experienced side effects. Absolute lymphocyte counts were more decreased in the treatment success group versus the treatment failure group: 1.1 (±0.7 SD) versus 0.6 (±0.6 SD); <.05. Eosinophil counts were more increased in the group with side effects versus the group without side effects: 3.8 (±5.5 SD) versus 1.2 (±2.5 SD); <.05. However, direct correlation studies showed no statistically significant correlations. Lymphopenia is associated with better clinical results of DMF treatment for psoriasis, whereas eosinophilia is associated with the occurrence of side effects.