Circulating CD8+ lymphocytes, white blood cells, and survival in patients with mycosis fungoides

Background There is a need for reliable, easily measurable laboratory markers that may help dermatologists to predict the course of mycosis fungoides (MF) when they first evaluate their patients. Objectives Our objective was to identify clinical, haematological or immunological parameters as predictors of mortality in patients with MF. Methods We conducted a retrospective study on a prevalent cohort of 124 patients with MF hospitalized at IDI-IRCCS, Rome, Italy, from 1983 to 2001. We calculated the proportion of patients surviving (Kaplan-Meier product-limit estimates) 5 and 10 years after first hospital admission, and hazard ratios (HR) from the Cox proportional hazards model. Results Patients' survival was linked to age and staging (lower survival in older patients and in patients with staging IIB-IV). Higher numbers of white blood cells (WBC) and neutrophils, lower numbers of CD8+ lymphocytes, low haematocrit and lower levels of albumin were significantly associated with a lower survival probability. When simultaneously accounting for age and staging, CD8+ [HR = 3.02, 95% confidence interval (CI) 1.01-9.07 for CD8+ < 250 vs. >= 600 cells mu L-1] and WBC (HR = 2.59, 95% CI 0.96-6.96 for WBC >= 9000 vs. < 6000 cells mu L-1) were associated with survival. In addition, we observed an exceedingly high risk of death (HR = 12.40, 95% CI 3.11-49.43) for patients with a combination of WBC >= 9000 and CD8+ < 600 cells mu L-1 vs. WBC < 9000 and CD8+ >= 600 cells mu L-1). Conclusions The measurement of CD8+ cells and WBC in MF seems to be a promising criterion to predict survival, and possibly to support treatment decisions and inclusion of patients in randomized controlled trials.