Objective: The present study was undertaken to evaluate the possible occurrence of immunological abnormalities in thalassaemia major patients treated with deferiprone (L1). Methods: Longitudinal observational cohort study. Results: The absolute number of CD8+ lymphocytes was high and the CD4/CD8 ratio low before L1 treatment; these parameters returned to normal after 3 months of L1 treatment. TNF-α, IL-2 and IL-2sRα were elevated before L1 treatment (11.83 ± 1.75, 11.75 ± 3.91, 1,409 ± 621 pg/ml, respectively), while IL-6 was normal (2.58 ± 0.79 pg/ml). After 12 months of treatment, IL-10 was higher than in previous periods, although always within the normal range. TNF-α, IL-2 and IL-2sRα returned to normal after 12, 6, and 3 months of L1 treatment, respectively.Copyright © 2002 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]