Neopterin and Interferon Gamma: Unveiling Their Prognostic Potential in COVID-19 with Diabetes Mellitus

Diabetes mellitus (DM) comorbidity increases the mortality risk in COVID-19 patients. Neopterin and Interferon-gamma (IFN-γ) are inflammatory markers involved in COVID-19 pathogenesis. This study aimed to evaluate the prognostic value of neopterin and IFN-γ as predictors of mortality in COVID-19 patients with DM comorbidity. We conducted a retrospective cohort study using clinical data and serum samples from COVID-19 patients with DM hospitalized at Dr. Saiful Anwar General Hospital, Malang, Indonesia, between January 2022 and July 2022. Neopterin and IFN-γ levels were measured from serum samples. This study included 179 COVID-19 patients: 94 with DM comorbidity and 85 without. The non-survival group had significantly higher neopterin levels than the survival group (p=0.0074). Path analysis showed that IFN-γ and neopterin each had independent prognostic effects on mortality, without functioning as confounders or intervening mediators along a single shared pathway. Kaplan-Meier curve analysis shows that IFN-γ levels ≥27.37 pg/mL and neopterin levels ≥9.770 nmol/L are associated with decreased life expectancy. In conclusion, neopterin and IFN-γ levels can serve as biomarkers for predicting mortality in COVID-19 patients with diabetes mellitus.