Type 2 cytokine serum levels in healthy sickle cell disease patients.

Sickle cell disease (SCD) is characterized by significant morbidity and early mortality. Children with this hemoglobinopathy exhibit many of the manifestations associated with immunodeficiency disorders. Serum was obtained from 56 healthy SCD subjects and 45 normal healthy controls. Type 2 cytokines interleukin (IL)-4, IL-6, and IL-10 serum levels were measured. Concentrations were determined by reference to a standard curve, and results were expressed in pg/mL. Results revealed significant levels of IL-4 in 6 (13%) of 45 SCD patients compared with 1 (2%) of 45 controls. Increased levels of IL-6 were present in 35 (78%) of 45 SCD patients and 12 (41%) of 29 controls. Elevated levels of IL-10 were detectable in 13 (41%) of 42 SCD patients and 1 (4%) of 25 controls. High circulating levels of type 2 cytokines may suppress both humoral and cell-mediated immune functions in SCD, with resultant increased morbidity.