Immunological evaluation of β-thalassemia major patients receiving oral iron chelator deferasirox

Abstract

Objective: To determine the immune abnormalities and occurrence of infections in transfusion-dependent β-thalassemia major patients receiving oral iron chelator deferasirox (DFX).

Study design: An observational study.

Place and duration of study: Hematology Clinics, King Khalid University Hospital, Riyadh, Saudi Arabia, from July to December 2010.

Methodology: Seventeen patients with β-thalassemia major (12 females, median age 26 years) receiving deferasirox (DFX) for a median duration of 27 months were observed for any infections and had their immune status determined. Immune parameters studied included serum immunoglobulins and IgG subclasses, serum complement (C3 and C4) and anti-nuclear antibody (ANA) level, total B and T-lymphocytes, CD4+ and CD8+ counts, CD4+/CD8+ ratio, and natural killer (NK) cells. Immunological parameters of the patients were compared with age, gender, serum ferritin level and splenectomy status. Lymphocyte subsets were also compared with age and gender matched normal controls.

Results: A considerable reduction in serum ferritin was achieved by DFX from a median level of 2528 to 1875 μmol/l. Serum IgG levels were increased in 7 patients. Low C4 levels were found in 9 patients. Total B and T-lymphocytes were increased in 14 patients each, while CD4+, CD8+ and NK cells were increased in 13, 12 and 11 patients respectively. Absolute counts for all lymphocyte subsets were significantly higher compared to the normal controls (p ² 0.05 for all parameters). Raised levels of IgG were associated with older age, female gender, splenectomized status and higher serum ferritin levels but this did not reach statistical significance except for the higher ferritin levels (p=0.044). Increased tendency to infections was not observed.

Conclusion: Patients with β-thalassemia major receiving DFX exhibited significant immune abnormalities. Changes observed have been described previously, but could be related to DFX. The immune abnormalities were not associated with increased tendency to infections.