Diagnostic Utility of CD64 and CD38 Biomarkers for the Differential Diagnosis of Infections.

Abstract

Purpose: Identification of infection type in patients with fever is particularly important in the emergency departments (EDs) of hospitals. This study was designed to evaluate the performance of two biomarkers, the modified neutrophil CD64 (nCD64) index and CD38 presence on T cells, using flow cytometry. Methods: A total of 305 potentially infected patients with fever were admitted to the ED of Zhongda Hospital (Nanjing, China) between March 2021 and August 2021. This study included three groups of patients: bacterial (N = 180), viral (N = 30) , and uninfected (N = 65) based on their final diagnostic outcomes and clinical records. Results: The expression level of traditional/modified nCD64 was significantly increased in the bacterial infection group, especially in case of patients infected with Gram-negative bacteria. The most prevalent species were Staphylococcus spp. and Escherichia coli. In contrast, CD3+CD38+ cell percentages were elevated in patients with viral infections, which were mostly caused by Epstein-Barr virus and cytomegalovirus. CD38 expression is age dependent, and higher percentages of CD3+CD38+ cells were observed in children with viral infections. For the prediction of bacterial infections, the area under the curve (AUC) of modified nCD64 (AUC: 0.800) was significantly higher than that of C-reactive protein and heparin-binding protein but slightly lower than that of traditional nCD64 (AUC: 0.831). The AUC, specificity, and sensitivity values for the prediction of viral infections using CD3+CD38+ cells percentages in children were 0.899 (0.785-1.000), 96.2%, and 85.9%, respectively. Conclusion: nCD64 levels and CD3+CD38+ cell percentage are potential biomarkers that facilitate identification of patients with bacterial and viral infections.