Evaluation of Th17 related cytokines associated with clinical and laboratorial parameters in sickle cell anemia patients with leg ulcers.

Leg ulcers (LUs) represent one of the main causes of morbidity in sickle cell anemia (SCA). This manifestation has been related to hemolysis, infections predisposition and inflammation that leads cytokines secretion. In this context, our study aimed to evaluate Th17 related cytokines (IL-6, IL-17A, IL-22 and IL-23) in serum and peripheral mononuclear cells culture supernatants with and without lymphoproliferative stimulation (anti-human CD3 and anti-human CD28). The cytokines levels were also correlated to clinical, hematological and biochemical parameters in SCA patients with and without LUs history (SCALU and SCAWH) as well as in healthy controls. In SCALU patients, high levels of IL-17A were associated with absence of acute chest syndrome (ACS, p=0.0328). The other clinical parameters analyzed (osteonecrosis, stroke, priapism, splenectomy and blood transfusions history) were not significantly related with other cytokine levels. In SCALU patients was also observed that IL-17A increased levels were associated with high levels of LDH (p=0.0130), the same association pattern was found for IL-6 (0.0160) and IL-22 (p=0.0165) in the SCALU group. Interestingly, we did not find statistical correlations with these parameters in SCAWH group. The other hematological parameters (hemoglobin, leucocyte and reticulocyte count) and indirect bilirrubin did not show any correlation with analyzed cytokines in both groups. So, for the first time, we show that IL-17A present in SCALU patients may exert a preventive role in the ACS development. Furthermore, IL-6, IL-17A and IL-22 accompanied the LDH levels only in SCALU patients suggesting to serve as additional markers of hemolysis or to be related with immunity response against extracellular pathogens.