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-gamma 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.

Serum neopterin for early assessment of severity of severe acute respiratory syndrome.

Neopterin and C-reactive protein (CRP) concentrations were determined in serum samples from 129 severe acute respiratory syndrome (SARS) patients and 156 healthy blood donors. In the patients with confirmed SARS, an early neopterin elevation was detected already at the day of onset of symptoms and rose to a maximum level of 45.0 nmol/L 3 days after the onset. All SARS patients had elevated neopterin concentrations (>10 nmol/L) within 9 days after the onset. The mean neopterin concentrations were 34.2 nmol/L in acute sera of SARS patients, 5.1 nmol/L in convalescent sera, and 6.7 nmol/L in healthy controls. In contrast, the mean CRP concentrations in both acute and convalescent sera of SARS patients were in the normal range (<10 mg/L). Serum neopterin level in SARS patients was associated with fever period and thus the clinical progression of the disease, while there was no significant correlation between the CRP level and the fever period. Serum neopterin may allow early assessment of the severity of SARS. The decrease of neopterin level was found after steroid treatment, which indicates that blood samples should be collected before steroid treatment for the neopterin measurement.