[Clinical Characteristics of Children with Hemophagocytic Syndrome with Different EB Virus DNA Loads].

Objective: To analyze the clinical characteristics of hemophagocytic syndrome (HLH) children with different EB virus (EBV) DNA loads, and to explore the relationship between differential indicators and prognosis.

Methods: Clinical data of 73 children with HLH treated in our hospital from January 2015 to April 2022 were collected. According to EBV DNA loads, the children were divided into negative group (≤5×10 copies/ml), low load group (>5×10-<5×10 copies/ml) and high load group (≥5×10copies/ml）. The clinical symptoms and laboratory indexes of the three groups were compared, and the ROC curve was used to determine the best cut-off value of the different indexes. Cox regression model was used to analyze the independent risk factors affecting the prognosis of children, and to analyze the survival of children in each group.

Results: The proportion of female children, the swelling rate of liver and spleen lymph nodes and the involvement rate of blood, liver, circulation and central nervous system in the high load group were higher than those in the negative group. The incidence of disseminated intravascular coagulation(DIC) and central nervous system(CNS) involvement in the high load group were higher than those in the low load group. The liver swelling rate and circulatory system involvement rate in the low load group were higher than those in the negative group(<0.05). PLT counts in the high load group were significantly lower than those in the negative group, and the levels of GGT, TBIL, CK-MB, LDH, TG, SF, and organ involvement were significantly higher than those in the negative group. The levels of CK, LDH, SF and the number of organ involvement in the high load group were significantly higher than those in the low load group. The levels of GGT and TBIL in low load group were significantly higher than those in negative group. In terms of treatment, the proportion of blood purification therapy in the high and low load group was significantly higher than that in the negative group(<0.01). ROC curve analysis showed that the best cut-off values of PLT, LDH, TG and SF were 49.5, 1139, 3.12 and 1812, respectively. The appellate laboratory indicators were dichotomized according to the cut-off value, and the differential clinical symptoms were included in the Cox regression model. Univariate analysis showed that LDH>1139 U/L, SF>1812 μg/L, dysfunction of central nervous system, number of organ damage, DIC and no blood purification therapy were the risk factors affecting the prognosis of children (<0.05); Multivariate analysis shows that PLT≤49.5×10/L and dysfunction of central nervous system were risk factors affecting the prognosis of children (<0.05). Survival analysis showed that there was no significant difference in the survival rate among the three groups.

Conclusion: The incidence of adverse prognostic factors in children with HLH in the EBV-DNA high load group is higher, and there is no significant difference in the survival rate of the three groups after blood purification therapy. Therefore, early identification and application of blood purification therapy is of great significance for children with HLH in the high load group.