Avaliação do status da vitamina D em pacientes com anemia falciforme: uma associação com biomarcadores de lesão renal aguda

Abstract

Sickle cell di se as e (SCD) i s a here ditary genetic di s eas e cau sed by a p o in t mutation in t he sixth codon of the β globin gene, leading to the replacement of glutamic acid by valine forming hemoglobin S (HbS). Under hypoxi c conditions Hb S acquires the ability to polymerize , changing the red cell morphology to sickle shape. This process result s in decreased red b lood cell survival in the circulation tr ig g ering in flammatory proces ses and vaso occlu sion phenomena. Hydroxyurea is the mai n tr eatment of SCD, being responsible for the increase in fetal hemoglobin, w hich reduces the polymerization of HbS V itamin D deficie n cy is a commo n nutrition conditio n a mo ng th e se indiv iduals that increase s the risk of its complications, and is associated with acute kidney injury . The kidney is very affected in SCD and sickl e cell nephropathy is one of its main comp li cat ion s. The p rogre ssion of kid ney injuries is mai nly due to the absence o f detection in ea rly stages. Thus the evaluation of innovative biomarkers , suc h as the kidney injury molecule 1 ( KIM 1) and the monocyt e chemotactic protein 1 MCP 1), w hic h ca n diagnose k idney injuri es in the s e individuals early , is extremely necessary . Therefore, the aim of this study w as to associate serum vitamin D levels among patients with SCD with biomarkers of renal fu n ction. The s tudy included 51 adult patien ts with SCD who were be ing m oni tore d at the Hematology S ervice of the Hospital Universi tário Wal ter Cantídio HUWC from December 2017 to M ay 2018. The control group was composed of 17 healthy blood donors in the same per iod. Serum levels o f 25 hydrox y v itamin D were determine d by ch e milu mi nescen t micro partic le immunoassay ( and renal function wa s accessed by measurements of urina ry creatinine, proteinuria, albuminur ia, KIM 1 and MCP 1 obtained from recent urine samples. Serum vitamin D levels were low in 45% of patient s No asso ciat i on was fo und between vitamin D leve ls and th e severity of anemia, fetal hemoglobin le vels and the frequency of vaso occlusive c rises. Regarding renal func t ion biomarkers , urinary protein ur ia, albuminuria, KI M 1 and MCP 1 levels were elev ate d in p ati en ts co mpared to the cont rol group. Finally, the unconventional biomarkers KIM 1 and MCP 1 were not associated with vitamin D status in patients with sickle cell anemia , making their use inc onclusive in predicting kidney damage