Identification of a high threshold value of serum ferritin in the diagnosis of hemophagocytic lymphohistiocytosis in hospitalized children in China

Objectives To explore and identify an optimal serum ferritin (SF) threshold level in diagnosing hemophagocytic lymphohistiocytosis (HLH) in Chinese children. Methods We conducted a retrospective study of 74 children with HLH admitted to Guangdong Women and Children Hospital between January 2015 and May 2021. Children in-hospital not diagnosed with HLH between January 2021 and May 2021 with a measurement of SF were enrolled as the non-HLH group. Patient charts were reviewed for SF levels upon admission and during hospitalization. A receiver operating characteristic (ROC) curve was utilized to determine the optimal cutoff value of SF for diagnosing childhood HLH. Results This study included a total of 74 children with HLH and 302 children with non-HLH diseases. The difference in SF values between the HLH and non-HLH groups was statistically significant (8,975 μg/L vs. 165.5 μg/L, p<0.001). An optimal SF cutoff value of 1,830 μg/L provided a sensitivity of 88 % and specificity of 79 % in confirming childhood HLH. The area under the curve (AUC) is 0.91 (95 % confidence interval 0.88–0.94, p<0.0001). Conclusions A serum ferritin level elevated above 1,830 μg/L might improve the specificity for HLH diagnosis in Chinese children.