A cellular immune response marker: Neopterin and its potential applications.

摘要

Neopterin measurement can be a very useful screening test when there is an outbreak of newly emerging infectious disease. Serum neopterin concentrations were elevated in patients suffering from severe acute respiratory syndrome and dengue fever as early as on the first day of the onset of symptoms.;Neopterin can also act as a gate-keeper in blood transfusion process to improve blood safety. A total of 3756 volunteer donors from Guangzhou Blood Transfusion centre were tested with neopterin. The upper reference levels were set as 11.5 nmol/L (95th percentile) and 14.7 nmol/L (98 th percentile), which were higher than the upper reference level (10 nmol/L, 98th percentile) set in Europe.;Neopterin measurement in the combination with other biomarkers is a very useful tool to differentiate viral infection from bacterial infection. The area under the receiver operating characteristic curve was the highest if the markers were used in combination. By using the C-reaction protein to neopterin (C/N) ratio, an optial cutoff at C/N ratio > 3 gave a sensitivity of 85% and a specificity of 82%.;InfectCheck NEO rapid test, a point of care test, for semi-quantitative detection of neopterin, has been successfully developed. The test result is available in 15 minutes. The analytic performance of the test was compared with a commercial neopterin ELISA and in a substantial agreement (kappa = 0.67). The intra-assay and inter-assay variations were within 20%. The InfectCheck NEO rapid test is stable at either 4°C or room temperature for up to 1 year without any significant loss of activity. It does not require any special expertise to perform the test nor specialized laboratory setting or expensive reading devices. It can act as an efficient gate-keeper at the triages of hosptials, clinics and blood transfusion centers to exclude viral infected patients.