Effect of recombinant alpha-interferon administration on peripheral blood lymphocyte subpopulations and natural killer cell activity in patients with refractory anemia with excess of blasts.

Peripheral blood lymphocyte subpopulations and natural killer cell activity (NKa) were determined in 7 patients with refractory anemia with excess of blasts (RAEB) subjected to alpha-interferon (alpha-IFN) administration. Patients received subcutaneously 3 MU alpha-IFN three times a week for 3 consecutive months, and studies were done just before and one month after the cessation of alpha-IFN administration. Before starting alpha-IFN, the patients NKa was severely reduced in relation to control (p less than 0.001), natural killer (NK) cells (CD16+ cells) and suppressor/cytolytic T-lymphocytes (CD8+ cells) were within normal range, while helper/inducer T-lymphocytes (CD4+ cells), as well CD4+/CD8+ cell ratio, were significantly reduced (p less than 0.001 and p less than 0.001, respectively). Significant diminution was also noted in B-lymphocyte numbers (CD19+ cells) (p less than 0.05). Following alpha-IFN administration, NKa values increased significantly in comparison to pre-IFN values (p less than 0.05), but failed to reach normal range. CD3+ cells and CD8+ cells decreased (p less than 0.05 and p less than 0.02), while CD4+ cells and CD4+/CD8+ cell ratio did not change significantly. A statistically significant rise was observed in CD16+ cells (p less than 0.05). The sensitivity of NK-cells against alpha-IFN and interleukin-2 (IL-2) added in vitro, was also significantly increased (p less than 0.05). The findings indicate that alpha-IFN administration may affect some disturbed immunologic functions in patients with RAEB, but further studies are needed to elucidate the mechanism and the extent of this action.