Fig. 3
From: Serum neopterin levels in relation to mild and severe COVID-19
Repeated measurements of serum neopterin concentrations in patients with mild (green) and severe (red) form of COVID-19 (n = 34). Severity (mild/severe), days since symptom onset, and age were used as covariates in the linear mixed effect model. The black dashed line represents the upper normal reference limit of neopterin at 9.1 nmol/L.