Cytokine release syndrome in Crimean-Congo hemorrhagic fever: can IL-1 receptor antagonist levels be a guide in its treatment?

- OBJECTIVE: Crimean-Congo Hemorrhagic Fever (CCHF) is a potentially fatal zoonotic viral disease involving fever and hem-orrhage. Our aim was to investigate the relation-ship between interleukin (IL)-1 and IL-1 recep-tor antagonist (RA) levels in patients with CCHF and the course of the disease and mortality, as well as to contribute to the literature at a time when new therapeutic protocols are being in-vestigated. PATIENTS AND METHODS: Sixty-one pa-tients with CCHF were admitted to our hospital's infectious diseases ward between March and September 2022, and 40 healthy people were in-cluded in the control group in our study. The pa-tients were divided into mild/moderate (n=35) and severe (n=26) CCHF groups depending on the clinical course. The patients with CCHF were also divided into surviving and exitus groups. IL-1 and IL-1RA levels were measured from blood specimens using the ELISA method. RESULTS: Significant elevation in IL-1 and IL-1RA levels was observed in CCHF cases with a severe manifestation compared to those with moderate disease. Both patient groups' IL-1 and IL-1RA levels were also significantly higher than those of the control group. In addition, IL-1 and IL-1RA levels were significantly higher among the exitus patients compared to the surviving CCHF patients. The laboratory values of lactate dehydrogenase (LDH), aspartate aminotransfer-ase (AST), alanine aminotransferase (ALT), cre-atinine phosphokinase (CK), platelet count, pro-thrombin time (PT), and activated partial throm-boplastin time (aPTT) were also significantly higher among the patients with severe manifes-tations compared to the moderate severity pa-tient group, and in the exitus patients compared to the survivors. However, platelet count and fi-brinogen levels were lower in the patients with a severe manifestation compared to the moderate severity group and in the exitus patients com-pared to the survivors. White blood cells (WBC) were higher in exitus patients than in survivors.CONCLUSIONS: IL-1 and IL-1RA levels were elevated in all the CCHF patients, while the high-er values in patients with a fatal course suggest that the inflammatory process is very severe and that IL-1 receptor antagonists may be need-ed in the treatment.