Dynamic Associations and Prognosis of Rhabdomyolysis in Patients With Severe Fever With Thrombocytopenia Syndrome

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging acute infectious disease. Current studies have mostly focused on its clinical characteristics and epidemiology, while research related to rhabdomyolysis (RM) remains limited. This study aimed to explore the relationship between RM and the prognosis of SFTS patients based on dynamic clinical data, identify dynamic associations with RM in SFTS patients, and provide a reference for early clinical identification and intervention. A retrospective analysis was performed on the clinical data of 537 SFTS patients admitted to Yijishan Hospital of Wannan Medical College and the First Affiliated Hospital of Nanjing Medical University. The patients were divided into the non-survivor group (N = 95) and survivor group (N = 442); additionally, they were categorized into the RM group (N = 74) and non-RM group (N = 463). Epidemiological data, clinical symptoms, and dynamic laboratory findings during the disease course were statistically analyzed. To screen associations with RM, univariate logistic regression analysis was conducted on laboratory findings obtained within 14 days of the disease course. Receiver operating characteristic (ROC) curves were further used to evaluate the predictive value of these associations with RM. Among the 537 SFTS patients, 95 (17.7%) were in the non-survivor group, of which 40 (42.10%) had concurrent RM; 442 (82.3%) were in the survivor group, of which 34 (7.69%) had RM. The difference in RM incidence between the two groups was statistically significant (p < 0.001). The mortality rate of the RM group (54.10%) was significantly higher than that of the non-RM group (11.90%) (p < 0.001). Dynamic laboratory findings indicated that the number of differential laboratory indicators in SFTS patients began to increase from day 5 of the disease course, with the most significant changes being observed between days 7-10. Dynamic univariate logistic analysis revealed that aspartate aminotransferase (AST), hematocrit (HCT), chloride (Cl), and blood urea nitrogen (BUN) were early associations with RM during the initial phase (days 1-4); additional associations including alanine aminotransferase (ALT), amylase (AMY), activated partial thromboplastin time (APTT), platelets (PLT), red blood cells (RBC), and thrombin time (TT) emerged during the progressive phase (days 5-7); associations during the multiple organ dysfunction (MOD) phase (days 8-10) included AST, creatinine (CR), d-dimer (D-D), lactate dehydrogenase (LDH), AMY, APTT, BUN, calcium (Ca), potassium (K), TT, monocytes (MONO), and international normalized ratio (INR); during the remission phase (days 11-14), associations were APTT, creatine kinase-MB (CKMB), CR, LDH, neutrophils (Neut), TT, white blood cells (WBC), AST, C-reactive protein (CRP), and K levels. ROC curve analysis showed that AST and BUN on day 3, and HCT and Cl on day 4 of the disease course had good predictive value for RM in SFTS patients. SFTS patients with RM have a high mortality rate, and the occurrence of RM is closely related to patient prognosis. The associations with RM in SFTS patients change dynamically with the disease course: the progressive phase is the critical period for rhabdomyolysis onset, and the MOD phase is the most life-threatening stage. AST, BUN, HCT, and Cl levels can be used as biomarkers for the early identification of RM in SFTS patients. Clinical stratified monitoring based on their high sensitivity and specificity is feasible, and these indicators are suitable for primary care promotion due to their low routine detection cost and fast turnaround time.