Detection of serum neopterin for early assessment of dengue virus infection

OBJECTIVE: Neopterin is generated and released in increased amounts by macrophages upon activation by interferon-γ during Th1-type immune response. The potential usefulness of neopterin in early prognostic information of dengue virus infection was investigated. METHODS: Neopterin concentrations were determined in serum samples from 110 dengue fever (DF) patients. The neopterin levels were compared with those in 50 measles and 40 influenza patients; 155 healthy blood donors served as controls. RESULTS: In acute sera of DF patients mean neopterin concentration was 48.2 nmol/L, which was higher than that in patients with measles (mean: 36.3 nmol/L) and influenza (18.8 nmol/L) and in healthy controls (6.7 nmol/L; P < 0.001). In the patients with confirmed DF, an early neopterin elevation was detected already at the first day after the onset of symptoms and rose to a maximum level of 54.3 nmol/L 4 days after the onset. Higher increase of neopterin level in DF patients was associated with longer duration of fever and thus predicted the clinical course of the disease. CONCLUSIONS: Neopterin concentrations were found significantly higher in DF patients compared with healthy controls and also with other viral infections (P < 0.001) and may allow early assessment of the severity of DF.