Expression and Clinical Significance of Serum sFas/sFasL in Patients with Secondary Hemophagocytic Lymphohistiocytosis

Abstract

To investigate the expression and clinical significance of soluble Fas (sFas) and sFasL in patients with secondary hemophagocytic lymphohistiocytosis (sHLH). From September 2015 to December 2020, 86 sHLH patients who met the HLH2004 diagnostic criteria were collected. They were divided into 55 cases in the MAHLH group and 31 cases in the NonMAHLH group according to the etiology. Thirty healthy persons were chosen as the normal control group, and 20 patients with systemic lupus erythematosus (SLE) were chosen as the disease control group. The expression levels of sFas and sFasL in the serum of patients with each group were detected by ELISA, and the clinical data were collected for statistical analysis. The significance of sFas and sFasL in sHLH was analyzed by ROC curve. Serum levels of sFas and sFasL in patients with newly diagnosed sHLH were significantly higher than those in disease control group and normal control group (P<0.01). The levels of sFas and sFasL in MAHLH group were significantly higher than those in nonMAHLH (infection related HLH and autoimmune disease related HLH) group (P<0.01). The serum levels of sFas and sFasL in 17 newly treated patients with sHLH (17/86) after treatment were significantly lower than those before treatment (P<0.01). The serum sFas level in newly diagnosed sHLH patients was positively correlated with SF(r=0.35), sCD25(r=0.79) and sFasL(r=0.73). The serum sFasL level was positively correlated with SF(r=0.39), sCD25(r=0.64) and sFas(r=0.73). Compared with the NonMAHLH group, the area under the ROC curve was 0.707 (95% CI: 0.593-0.821) (P=0.0015). The optimal critical value for diagnosing MAHLH by sFas level was 12 743 pg/ml, and the sensitivity and specificity were 70.9% and 71% respectively. Compared with the NonMAHLH group, the area under the ROC curve was 0.765(95% CI: 0.659-0.87)(P<0.01). The median OS time of sFas high expression group (≥16798.5 pg/ml) and sFasL high expression group (≥4 785 pg/ml) was significantly shorter than that of the low expression group (P<0.001). Serum levels of sFas and sFasL can be used for the early diagnosis and differential diagnosis of sHLH disease, and are the factor related to the poor prognosis of sHLH.