Changes in the Levels of the Serum Markers Serum Amyloid A and Immunoglobulin M in Children with Mycoplasma pneumoniae Infection Complicated with Asthma and Their Clinical Significance.

Asthma represents a chronic disorder with aberrant immunological and inflammatory responses. We analyzed the levels and clinical significance of serum markers serum amyloid A (SAA) and immunoglobulin M (IgM) in Mycoplasma pneumoniae (MP)-infected children with asthma. MP-infected children were allocated into the Asthma (n = 64) and N-Asthma (n = 104) groups, with baseline information collected. Levels of IgE, c-reactive protein, procalcitonin, lactate dehydrogenase, aspartate aminotransferase, interleukin-4/interferon-γ (IL-4/IFN-γ), transforming growth factor β1 (TGF-β1), SAA and IgM were determined by ELISA. Tidal breathing lung function [inspiratory time (TI), expiratory time (TE), inspiratory volume (V-TI), expiratory volume (V-TE), tidal volume (VT) and respiratory rate (RR)] was assessed using a pulmonary function instrument. The relationship of serum SAA and IgM with IgE, IL-4/IFN-γ, TGF-β1, and tidal breathing lung function in MP-infected asthmatic children, and their diagnostic value for asthma occurrence in MP-infected children were analyzed by Spearman analysis and receiver operating characteristic curve. IgE, V-TI, V-TE, VT, IL-4/IFN-γ, TGF-β1, SAA and IgM indexes in MP-infected asthmatic children surpassed those without asthma. Serum SAA and IgM significantly positively correlated with IgE, IL-4/IFN-γ, TGF-β1, V-TI, V-TE and VT, which had certain diagnostic value for asthma in MP-infected children. The incidence of asthma was higher in MP-infected children with high SAA and IgM expression levels. The diagnostic efficacy of SAA and IgM combined test surpassed single detection. Serum SAA and IgM were highly expressed in MP-infected asthmatic children, and their combined detection had high diagnostic value for asthma in MP-infected children.