Abstract:Objective To investigate the clinical manifestations and laboratory examination results of children with Kawasaki disease complicated by macrophage activation syndrome (KD-MAS), and to provide a basis for identifying early warning indicators for the early diagnosis and treatment of KD-MAS.Methods A retrospective study was performed on 27 children with KD-MAS (KD-MAS group) and 110 children with KD (KD group) who were admitted to Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, from January 2014 to January 2022. Clinical and laboratory data were compared between the two groups. The receiver operating characteristic (ROC) curve was used to investigate the value of laboratory markers with statistical significance in the diagnosis of KD-MAS.Results Compared with the KD group, the KD-MAS group had significantly higher incidence rates of hepatomegaly, splenomegaly, incomplete KD, no response to intravenous immunoglobulin, coronary artery damage, multiple organ damage, and KD recurrence, as well as a significantly longer length of hospital stay (P<0.05). Compared with the KD group, the KD-MAS group had significantly lower levels of white blood cell count, absolute neutrophil count, hemoglobin, platelet count (PLT), erythrocyte sedimentation rate, serum albumin, serum sodium, prealbumin, and fibrinogen (FIB), a significantly lower incidence rate of non-exudative conjunctiva, and significantly higher levels of C-reactive protein, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase (LDH), and serum ferritin (SF) (P<0.05). The ROC curve analysis showed that SF, PLT, FIB, and LDH had high value in the diagnosis of KD-MAS, with areas under the curve (AUC) of 0.989, 0.966, 0.932, and 0.897, respectively (P<0.001), and optimal cut-off values of 349.95 μg/L, 159×109/L, 3.85 g/L, and 403.50 U/L, respectively. The combination of SF, PLT, FIB, and LDH had a larger AUC than PLT, FIB, and LDH alone in the diagnosis of KD-MAS (P<0.05), but there was no significant difference in the AUC between the combination of SF, PLT, FIB, and LDH and SF alone (P>0.05).Conclusions KD-MAS should be considered when children with KD have hepatosplenomegaly, no response to intravenous immunoglobulin, coronary artery damage, and KD recurrence during treatment. SF, PLT, FIB, and LDH are of high value in the diagnosis of KD-MAS, especially SF is of great significance in the diagnosis of KD-MAS.