Interleucina 18: influência sobre parâmetros hematológicos e níveis de hemoglobina fetal em pacientes com Anemia falciforme atendidos no hemocentro de Fortaleza-CE

Abstract

The pathophysiological process of Sickle Cell Anemia (SCA) is associated with inflammatory phenomena that lead to vaso-occlusive crises. Consequently, several cytokines are secreted, including interleukin-18 (IL-18), which can stimulate the production of interferon-gamma (IFN-γ). The objective of this study was to evaluate the influence of IL-18 and IFN-γ on hematological parameters and fetal hemoglobin (HbF) levels in patients with SCA treated at a blood center in Fortaleza, Ceará, Brazil. This was a cross-sectional, observational, descriptive, and analytical study. The research was conducted at the Ceará Hematology and Hemotherapy Center (HEMOCE) and analyzed at the Laboratory of Clinical and Toxicological Analyses (LACT) of the Department of Clinical and Toxicological Analysis at the Federal University of Ceará (UFC). A total of 116 volunteers of both sexes participated in the study, including 85 individuals with Sickle Cell Anemia (SCA) in a steady state, of whom 73 were undergoing treatment with Hydroxyurea (HU) and 12 were not receiving the medication. Additionally, 31 volunteers comprised the Control Group. Blood samples were collected for the analysis of IL-18 and IFN-γ cytokines, and demographic and laboratory data were obtained from medical records between July 2021 and May 2022. The hematological variables—leukocytes, erythrocytes, hemoglobin, platelets, and red cell indices—showed significant differences between the sickle cell anemia (SCA) group and the control group. Fetal hemoglobin (HbF) exhibited a negative correlation with leukocytes (ρ = -0.489), neutrophils (ρ = -0.483), platelets (ρ = -0.282), and reticulocytes (ρ = -0.325), and a positive correlation with hemoglobin levels (ρ = 0.350). IL-18 and IFN-γ levels were significantly higher in the SCA group (p < 0.001) and did not differ between hydroxyurea (HU) users and non-users. In SCA patients, IL-18 correlated with leukocytes (ρ = 0.260), neutrophils (ρ = 0.260), HbS (ρ = 0.327), and HbF (ρ = -0.244). Among HU users, IL-18 was associated with HbS (ρ = 0.369) and HbF (ρ = -0.246), and IFN-γ showed a negative correlation with reticulocyte counts (ρ = -0.281). It was concluded that increased IL-18 levels were associated with hematological parameters, including elevated leukocyte, neutrophil, and HbS levels. Conversely, a negative correlation was observed between IL-18 levels and HbF. No associations were found between the analyzed parameters and increased IFN-γ levels.