Expression and Correlation Analysis of Neuropeptide Family Members in the Peripheral Blood of Patients with COVID-19

The purpose of this article is to investigate the expression of neuropeptide family members and their correlation with inflammatory indicators in the peripheral blood of children infected with COVID-19.

Blood samples were collected from 40 hospitalized newly diagnosed children with confirmed COVID-19 infection and 17 hospitalized children with non-COVID-19 bronchial pneumonia during the same period. Baseline clinical data were collected and analyzed. Expression and correlation analysis of neuropeptide-related molecules [ACE (Angiotensin Converting Enzyme), ACE2 (Angiotensin Converting Enzyme 2), ASCL1 (achaete-scute family bHLH transcription factor 1)] in peripheral blood were detected and analyzed by ELISA. Complete blood counts with differentials, C-Reactive Protein (CRP), liver enzymes, Substance P (SP), Vasoactive Intestinal Polypeptide (VIP), and Gastrin-Releasing Peptide (GRP) were also measured.

The results of 40 COVID-19 patients (43% males) and 17 non-COVID-19 patients (71% males) were compared. ACE2 in non-COVID-19 and moderate COVID-19 groups was higher than that in severe groups (p=0.04; p=0.03, respectively). ASCL1 in the non-COVID-19 group was higher than that in the COVID-19 group (p=0.04). ASCL1 in the non-COVID group was higher than that in the severe COVID group (p=0.02). There were no significant differences in SP, VIP, and GRP between COVID-19 and non-COVID-19 groups. ASCL1 correlated negatively with blood neutrophils (%) (r = -0.534, p<0.001), CRP (r = -0.522, p<0.001), but positively with lymphocytes (%) (r = 0.572, p<0.001), and aspartate aminotransferase (r = 0.496, p=0.001). There was no significant correlation between SCL1 and white blood cell count, platelet count, alanine transaminase, or Lactate dehydrogenase.

The negative correlation between ASCL1 and neutrophil percentage (N%) and CRP suggests that ASCL1 may modulate the inflammation associated with pediatric COVID-19, positioning it as a potential biomarker and therapeutic target. The study's findings suggest that ASCL1 is downregulated in pediatric COVID-19 and correlates negatively with neutrophil percentage and CRP, indicating a potential regulatory role in COVID-19-related inflammation. Unlike adults, ACE/ACE2 are not highly expressed in children, which may partly explain the milder disease course. ASCL1 may represent a novel biomarker and therapeutic target worthy of further investigation in larger pediatric cohorts.

Unlike adults, ACE and ACE2 are not highly expressed in children with COVID-19. ASCL1 in children with COVID-19 is lower than that in non-COVID-19 children. ASCL1 is negatively correlated with N% and CRP, suggesting that ASCL1 may have a role in COVID-19 inflammation.