Clinical significance of peripheral blood CD11b(+)/CD33(+)/HLA-DR(-) myeloid cells in infants and children with infectious diseases and increased CRP

Background: At early ages, recurrent or persistent infections are associated with increased serum C-reactive protein (CRP). Inflammatory mediators release inhibitory cells named myeloid-derived suppressor cell (MDSC) into circulating and tumor tissues. In the present study, we assayed the percentage and count of whole blood CD11b(+)/CD33(+)/HLA-DR(-) MDSCs or myeloid cells at early ages with infectious diseases and increased CRP. Methods: In this study, the clinical significance of CD11b(+)/CD33(+)/HLA-DR(-) MDSCs or myeloid cells was evaluated in whole blood samples from 40 patients with infectious disease and 20 healthy controls by flow cytometry analysis. Subsequently, the Pearson correlation between the percentage and absolute count of MDSCs with clinical parameters were obtained by SPSS analysis. A p value of < 0.05 was considered statistically significant. Results: We found a significantly higher level of MDSCs in infants and children with infectious diseases and increased CRP as compared to healthy controls (P=0.003). However, the results of analysis showed no correlation between MDSC percentage and count with grouped age and sex in patient groups. Conclusion: Our findings showed a significant correlation between the high level of serum CRP and peripheral blood CD11b(+)/CD33(+)/HLA-DR(-) MDSCs at early ages. This study could be a roadmap for future studies to use increased CRP as a potential prognostic biomarker to target MDSCs in children with recurrent or persistent infections.