Serum Neopterin in Differential Diagnosis of Bacterial Diarrhea in Pediatric Patients

Abstract Background: Neopterin, regarded as a marker of cellular immune activation, has been used in diagnosis of infection caused by intracellular pathogens. We have aimed to evaluate the clinical usefulness of serum neopterin (NPT) in acute bacterial diarrhea caused by group C enteropathogenic Escherichia coli (EPECs) and group D Salmonella spp. Methods: Serum concentration of NPT was determined by ELISA. The study group included 47 children with diagnosis of bacterial diarrhea: 32 caused by group C enteropathogenic Escherichia coli (EPECs) and 15 by group D Salmonella spp. 105 healthy children constituted the control group. Results: Serum concentration of NPT in children infected with group D Salmonella spp. turned out to be higher than in the other groups. The fraction of Salmonella-infected patients with serum neopterin above 11 nmol/l proved higher as compared to children with diarrhea caused by group C EPECs or to the healthy controls. The prevalence of a C-reactive protein (CRP) to NPT ratio of greater than 1 did not differ significantly between children with diarrhea of various etiology. Conclusions: Neopterin can be used as a non-specific marker differentiating between bacterial diarrhea of various etiology.