Relationships of serum amyloid A, eotaxin and pentraxin 3 levels with lung function indexes, Mycoplasma pneumoniae DNA level and prognosis in children with Mycoplasma pneumoniae pneumonia

Objective To investigate the relationships of serum amyloid A (SAA), eotaxin and pentraxin 3 (PTX3) levels with Mycoplasma pneumoniae DNA (MP-DNA) level, lung function and prognosis in children with Mycoplasma pneumoniae pneumonia (MPP).

Methods A total of 163 children with MPP were enrolled in MPP group and divided into good prognosis group (n=109) and poor prognosis group (n=54) based on prognosis; another 124 healthy children with physical examinations in the same period were included as control group. Levels of serum SAA, eotaxin and PTX3 were measured in the children. Multivariable Logistic regression analysis was conducted to explore risk factors for poor prognosis in children with MPP.

Results Compared with the control group, the MPP group had significantly increased levels of SAA, eotaxin, PTX3 and MP-DNA positivity (P < 0.01); the MPP group also had significantly lower values of peak expiratory flow (PEF), forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), tidal expiratory flow time to total expiratory time (tPTEF/TE), and tidal volume compared with the control group (P < 0.01). Compared with the good prognosis group, the poor prognosis group had significantly increased MP-DNA level, SAA, eotaxin and PTX3 levels, as well as decreased values of PEF, FEV₁, FVC, tPTEF/TE and tidal volume (P < 0.01). Multivariable Logistic regression analysis showed that high MP-DNA level, high SAA, eotaxin and PTX3 levels, low values of PEF, FEV₁, FVC, tPTEF/TE and tidal volume were risk factors for poor prognosis in children with MPP (P < 0.01). The SAA, PTX3 and eotaxin levels in children with MPP were positively correlated with their MP-DNA level and negatively correlated with lung function indicators (P < 0.05).

Conclusion SAA, PTX3 and eotaxin levels are positively correlated with MP-DNA level and negatively correlated with lung function indicators in children with MPP. SAA, PTX3 and eotaxin levels can be used to assess the prognosis of children with MPP.