The Changes Of Serum Leptin Concentrations During Severe Infectious Diseases With Bacteria In Children

Objective Infectious diseases (ID) is most common diseases in children. The severity of HD depends on the pathogenicity of different pathogen. And most importantly,it depends on the status of immunological function. Leptin is a proteohormone encoded by the obese gene and produced by adipocytes, which is involved with metabolism. It is recently reported that leptin levels are elevated with increasing cytokines, especially Tumor Necrosis Factor Alpha (TNF-a), endotoxin and glucocorticoid. It is also reported that leptin levels are decreased in ID. This study detected leptin and TNF-a duing severe ID with bacteria to clarify the correlation between leptin and ID, and analyze the mechanism and significance of the change.Method Leptin and TNF-a during acute and recovery phases were detected by Im-munoradiometric Assay(IRMA) and Enzyme Amplified Sensitivity Immunoassay(EASIA) in 33 severe ID with bacteria,respectively,and the results were compared with control group. Leptin and TNF-a levels of different ID were analized by linear correlation a-nalysis.Results Leptin levels in severe ID with bacteria were lower during acute phases than those in control group(P<0. 05),and increased gradually during recovery phases. TNF-a levels during acute ID were significantly higher than those during recovery phase and those in control group,respectively(P<0. 001). Leptin levels,in acute ID,were negative correlative with TNF-a,and depend on the severity of infection.Conclusion This study shows that leptin levels were downregulated during acute ID in human, and have a negative correlation with TNF-alevels. Detecting leptin concentrations is of great significance to the judgement of the severity of ID. The results provided objective data for the endocrine and immunological network.