Neopterin as a marker of congenital cytomegalovirus infection.

Background and aims: Neopterin is a marker of cellular immune activation during viral and parasitic infections, with levels typically declining during treatment. Elevated neopterin levels have been observed in the cerebrospinal fluid (CSF) in patients with neuroinfections. This prospective case-control study aimed to evaluate the diagnostic value of neopterin concentrations in body fluids in congenital cytomegalovirus infection (cCMV).

Methods: Neopterin concentrations were measured in serum, urine and CSF of neonates with confirmed cCMV and compared with a control group. Clinical and audiological examination, biochemical tests, neuroimaging, viral loud in blood and urine and CMV DNA in CSF were performed at baseline and during treatment.

Results: The study group included 58 infants with cCMV (45 (78 %) symptomatic). There were higher baseline neopterin concentrations in the study group than in the control group. Baseline serum neopterin concentrations were higher in infants with intrauterine growth restriction, microcephaly, hepatosplenomegaly, petechiae and with hearing loss. There were higher neopterin concentrations in CSF in infants with clinical symptoms, hearing loss, and those with neuroimaging abnormalities. Neopterin concentrations in body fluids demonstrated good discriminatory ability as a diagnostic marker for cCMV, with an area under the ROC curve (AUC) values of 0. 977 for CSF, 0.895 for serum and 0.87 for urine. Neopterin concentrations were decreasing during treatment.

Conclusions: Serum neopterin concentration may serve as an diagnostic marker reflecting disease severity and can be useful for monitoring the effectiveness of the antiviral treatment. Neopterin concentration in CSF indicates the role of the local immune response of CNS injury.