Abstract:Objective To investigate the efficacy and application value of plasma exchange as an adjuvant therapy in children with hemophagocytic syndrome (HPS). Methods A prospective randomized controlled trial was designed. Forty children with severe HPS were enrolled, who were treated in the pediatric intensive care unit (PICU) of Hunan Children's Hospital from October 2018 to October 2020. The children were randomly divided into a plasma exchange group and a conventional treatment group using a random number table, with 20 children in each group. The children in the conventional treatment group received etiological treatment and conventional symptomatic supportive treatment, and those in the plasma exchange group received plasma exchange in addition to the treatment in the conventional treatment group. The two groups were compared in terms of general information, clinical symptoms and signs before and after treatment, main laboratory markers, treatment outcome, and prognosis. Results Before treatment, there were no significant differences between the two groups in gender, age, course of the disease before admission, etiological composition, pediatric critical illness score, involvement of organ or system functions, and laboratory markers (P>0.05). After 7 days of treatment, both groups had remission and improvement in clinical symptoms and signs. After treatment, the plasma exchange group had significantly lower levels of C-reactive protein, procalcitonin, and serum protein levels than the conventional treatment group (P<0.05). The plasma exchange group also had significantly lower levels of alanine aminotransferase and total bilirubin than the conventional treatment group (P<0.05). The length of stay in the PICU in the plasma exchange group was significantly shorter than that in the conventional treatment group (P<0.05). The plasma exchange group had a significantly higher treatment response rate than the conventional treatment group (P<0.05). There were no significant differences between the two groups in the total length of hospital stay and 3-month mortality rate (P>0.05). Conclusions Plasma exchange as an adjuvant therapy is effective for children with severe HPS. It can improve clinical symptoms and signs and some laboratory markers and shorten the length of stay in the PICU, and therefore, it may become an optional adjuvant therapy for children with severe HPS.