High serum levels of neopterin in patients with Crimean–Congo hemorrhagic fever and its relation with mortality

OBJECTIVE: Neopterin is generated and released in increased amounts by macrophages upon activation by interferon-gamma during cellular immune response. In this study, we aimed to investigate serum neopterin levels in patients with Crimean–Congo hemorrhagic fever (CCHF) and its clinical significance as a predictor factor of mortality. METHODS: Neopterin concentrations on the first day of hospitalization were measured in serum samples from 51 CCHF patients. Serum neopterin levels and other clinical–laboratory parameters for fatal and nonfatal CCHF patients were compared. RESULTS: Serum neopterin levels (73.22 ± 54.30 nmol/L) were highly elevated in all CCHF patients (p < 0.0001) with higher levels in fatal group (153.66 ± 81.34 nmol/L, p = 0.0001) compared to nonfatal disease (55.99 ± 24.09 nmol/L). In univariate analysis, the level of neopterin on the first day of hospitalization, bleeding, platelet count, aspartate transferase and lactate dehydrogenase were associated with mortality. In multivariate analysis, only the serum level of neopterin was associated with mortality. As a mortality risk factor, area under the curve was 0.939 (p = 0.0001, 95% confidence interval: 0.85–1.00). CONCLUSIONS: In this first study of serum neopterin levels for CCHF, elevated serum neopterin level showing strong activation of monocytes/macrophages was a risk factor for CCHF.