RESUMO
Serum soluble Fas (sFas) levels are associated with erythropoietin (Epo) hyporesponsiveness in patients with chronic kidney disease (CKD). Whether sFas could predict the need for erythropoiesis-stimulating agent (ESA) usage and its influence in erythropoiesis remain unclear. We evaluated the relation between sFas and ESA therapy in patients with CKD with anemia and its effect on erythropoiesis in vitro. First, we performed a retrospective cohort study with 77 anemic patients with nondialysis CKD. We performed in vitro experiments to investigate whether sFas could interfere with the behavior of hematopoietic stem cells (HSCs). HSCs were isolated from umbilical cord blood and incubated with recombinant sFas protein in a dose-dependent manner. Serum sFas positively correlated with Epo levels (r = 0.30, P = 0.001) but negatively with hemoglobin (r = -0.55, P < 0.001) and glomerular filtration rate (r = -0.58, P < 0.001) in patients with CKD at baseline. Elevated sFas serum levels (4,316 ± 897 vs. 2,776 ± 749, P < 0.001) with lower estimated glomerular filtration rate (26.2 ± 10.1 vs. 33.5 ± 14.3, P = 0.01) and reduced hemoglobin concentration (11.1 ± 0.9 vs. 12.5 ± 1.2, P < 0.001) were identified in patients who required ESA therapy compared with patients with non-ESA. Afterward, we detected that the sFas level was slight correlated with a necessity of ESA therapy in patients with nondialysis CKD and anemia. In vitro assays demonstrated that the erythroid progenitor cell frequency negatively correlated with sFas concentration (r = -0.72, P < 0.001). There was decreased erythroid colony formation in vitro when CD34+ HSCs were incubated with a higher concentration of sFas protein (1.56 ± 0.29, 4.33 ± 0.53, P < 0.001). Our findings suggest that sFas is a potential predictor for ESA therapy in patients with nondialysis CKD and that elevated sFas could affect erythropoiesis in vitro.
Assuntos
Anemia/sangue , Eritropoese , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Multipotentes/metabolismo , Insuficiência Renal Crônica/complicações , Receptor fas/sangue , Adulto , Idoso , Anemia/diagnóstico , Anemia/tratamento farmacológico , Anemia/etiologia , Biomarcadores/sangue , Brasil , Células Cultivadas , Tomada de Decisão Clínica , Bases de Dados Factuais , Eritropoese/efeitos dos fármacos , Eritropoetina/sangue , Feminino , Hematínicos/uso terapêutico , Células-Tronco Hematopoéticas/efeitos dos fármacos , Hemoglobinas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Células-Tronco Multipotentes/efeitos dos fármacos , North Carolina , Seleção de Pacientes , Valor Preditivo dos Testes , Proteínas Recombinantes/farmacologia , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico , Estudos RetrospectivosRESUMO
The aims of this study were to assess serum Fas, FasL, TRAIL, and Bcl-2 levels in patients with juvenile-onset systemic lupus erythematosus (JSLE) and to evaluate their relations with disease activity parameters and nephritis. Forty-eight JSLE patients, 33 juvenile idiopathic arthritis (JIA, inflammatory controls) patients and 40 healthy controls were enrolled. sFas, sFasL, sTRAIL, and sBcl-2 serum levels were measured by ELISA. Disease activity parameters included SLEDAI score, ESR, anti-dsDNA antibodies, C3, and C4 levels. Thirty-five JSLE patients had nephritis and 32 patients were classified as having active disease (SLEDAI ≥4). Statistical analysis methods included Mann-Whitney test and Spearman's rank test. JSLE patients had significantly increased sFas serum levels compared with healthy controls (median 177.6 vs. 117.5 pg/mL; p = 0.0001), higher sTRAIL (median 484.6 vs 270.8 pg/mL; p = 0.02), and reduced sFasL (median 0.05 vs 0.3 ng/mL; p = 0.0002). The same results were observed for JSLE patients with active disease and for patients with nephritis. Additionally, sFas levels in JSLE patients directly correlated with SLEDAI score (r = 0.40; p = 0.009), and sTRAIL levels were increased in JSLE patients with neuropsychiatric disease compared with those without this involvement (median 667.9 vs. 216.2 pg/mL; p = 0.03). Otherwise, sBcl-2 levels of JSLE patients were similar to healthy controls. JIA patients had sFas, sFasL, sTRAIL, and sBcl-2 serum levels similar to JSLE patients and to healthy controls. In summary, this study characterized in JSLE a distinct profile from adult SLE that comprises increased sFas, sTRAIL, and reduced sFasL, notably in patients with active disease and with nephritis.