leptin and Respiratory-Syncytial-Virus-Infections

Neuroendocrine hormones have profound effects on the immune system. The immune response is a major factor in the pathogenesis of acute respiratory syncytial virus (RSV) infection. We hypothesised that there is a relationship between the neuroendocrine response in acute RSV infection, the severity of illness, and the degree of lymphopenia.. Prospective, non-randomised cohort study of infants hospitalised for RSV infection requiring mechanical ventilation or managed conservatively. The study assessed the effect of age, gender, birth gestation, and severity of illness on stress hormone profile and its relationship to lymphocyte count.. Regional Paediatric Intensive Care Unit (PICU) and children's wards.. Thirty-two consecutive infants with RSV infection were enrolled, of which thirteen were mechanically ventilated on PICU (study subjects) and nineteen treated on the ward (comparison group). Twenty-three children (72%) returned for follow-up.. A specific neuroendocrine profile was found in PICU patients compared to ward patients (Wilks Lambda = 0.36, F = 9.05, P =.03). PICU patients had significantly higher prolactin and growth hormone, and significantly lower leptin and IGF-1. Cortisol levels were the same. PICU patients were more lymphopenic compared to ward patients (P =.0001). On multiple regression analysis, prolactin and leptin levels accounted for 57% of the variation in lymphocyte count.. Whereas the effect of intensive care (mechanical ventilation and medication) could not be controlled for, our results suggest that there is an association between the neuroendocrine hormone response, severity of illness and degree of lymphopenia.

Topics: Acute Disease; Analysis of Variance; Bronchiolitis; Female; Humans; Hydrocortisone; Infant; Intensive Care Units, Pediatric; Leptin; Lymphopenia; Male; Neuroimmunomodulation; Neurosecretory Systems; Prolactin; Respiration, Artificial; Respiratory Syncytial Virus Infections; Severity of Illness Index

Infection of human bronchial epithelial cells (hBECs) with respiratory syncytial virus (RSV) has been shown to induce a Th lymphocyte subset drift, e.g. enhanced differentiation of Th2 and Th17 subsets, which is a classic characteristic of asthma. However, the molecules responsible for the drift in Th subsets remain unknown. This study aims to determine the expression of leptin in RSV-infected hBECs, and its role in Th2 and Th17 cell differentiation and extracellular regulated kinase (ERK) 1/2 phosphorylation.. Cultured hBECs were infected with RSV. mRNA expression of the LEP gene in cells was measured by real-time PCR while LEP protein secretion in culture medium was measured by ELISA. Th differentiation was investigated in cultured human peripheral blood mononuclear cells following stimulation with recombinant human leptin. Th2 and Th17 subsets were examined by flow cytometry. Phosphorylation of the ERK1/2 protein in lymphocytes was detected by Western blot and immunofluorescence.. LEP mRNA expression was significantly upregulated in RSV-infected hBECs while the leptin protein level in the supernatants of RSV-infected hBECs was significantly increased. Stimulation of lymphocytes with leptin increased the differentiation of the Th17 subset and ERK1/2 phosphorylation, but suppressed Th2 subset differentiation.. Leptin was oversecreted by RSV-infected hBECs, which promoted Th17 subset differentiation but suppressed Th2 subset differentiation possibly via regulating ERK1/2 phosphorylation.

Topics: Asthma; Cell Differentiation; Cell Line; Epithelial Cells; Extracellular Signal-Regulated MAP Kinases; Humans; Leptin; Phosphorylation; Respiratory Mucosa; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; RNA, Messenger; Th17 Cells; Th2 Cells

To determine the role of serum leptin in infants with wheezing after respiratory syncytial virus infected.. 43 infants infected with RSV were given blood samples to detect leptin concentration with radioimmunoassays (RIA) within 24 hours after admission into hospital, discharged and 12 weeks later. Then, they were followed up for 2 years. 10 healthy children of the same age served as controls.. 41.9% infants developed asthma after infected with RSV. Compared to control group, the serum level of leptin in the asthma group and non-asthma group were significantly higher before treatment (t = 3.41 and 2.64 respectively, P < 0.05). When they were discharged, the serum level of leptin in the asthma group was significantly higher than that in non-asthma group and control group (t = 5.74 and 6.23, respectively, P < 0.05). 12 weeks later, the serum level of leptin in the asthma group was still significantly higher than that in non-asthma group and control group (t = 6.32 and 6.11, respectively, P < 0.05), but there were no difference between non-asthma group and control group (t = 0.81, P > 0.05).. The serum level of leptin in infants with asthma after RSV infected was higher than that in healthy and non-asthma children. Persistent higher level of leptin may play an important role in infants with asthma after RSV infected.

Topics: Asthma; Case-Control Studies; Child, Preschool; Female; Follow-Up Studies; Humans; Infant; Leptin; Male; Respiratory Sounds; Respiratory Syncytial Virus Infections; Respiratory Syncytial Viruses