ABSTRACT
Objective:To analyze the clinical characteristics of patients suffering from plastic bronchitis (PB) caused by Mycoplasma pneumoniae (MP) and explore its risk factors as well. Methods:A retrospective analysis on clinical and laboratory data of PB children caused by MP and treated in Department of Respiratory in Children′s Hospital of Soochow University from January 2011 to December 2017, compared with MP pneumonia(MPP) children without PB in the same period.Meanwhile, Logistic regression analysis was performed. Results:Among the 306 MPP children, there were 50 cases in the PB group and 256 cases in the non-PB group.Compared with children in the non-PB group, children in PB group were higher in terms of age [(82.74±35.17)months vs.(66.63±35.67) months], percentage of neutrophils (0.705 8±0.139 1 vs.0.605 7±0.162 6), C reactive protein(CRP) [17.4(10.21, 42.86) mg/L vs.11.43(4.55, 23.66) mg/L], D-dimer(DD) [1 071 (279.5, 2 386.5) μg/L vs.523 (233, 1 099.5) μg/L], lactate dehydrogenase(LDH) [491.1 (342.3, 607.4) U/L vs.394.9 (319.1, 512.8) U/L], erythrocyte sedimentation rate(ESR)[25.0 (17.0, 36.0) mm/1 h vs.15.5(9.0, 28.0) mm/1 h], aspartate aminotranferase(AST) [33.5(26.1, 49.3) U/L vs.29.2(24.0, 37.2) U/L], alanine aminotransferase (ALT) [19.1(11.45, 31.50) U/L vs.13.6 (10.3, 23.15) U/L], IgA [1.46(0.98, 2.12) mg/L vs.1.15 (0.64, 1.60) mg/L], CD3 -CD (16+56)+ (0.155 0±0.088 6 vs.0.120 2±0.071 5), allergy history [44.0%(22/50 cases) vs.25.8%(65/256 cases)], mixed infection [38.0% (19/50 cases) vs.24.6%(63/256 cases)], and microscopic mucosal erosion [10.0%(5/50 cases) vs.2.3%(6/256 cases)] (all P<0.05). Logistic regression analysis displayed that allergy history ( OR= 5.604, 95% CI: 1.937-16.216), age ( OR = 3.142, 95% CI: 1.425-6.929), percentage of neutrophils ( OR=2.387, 95% CI: 1.088-5.238), CRP ( OR=3.959, 95% CI: 1.072-14.662), and DD ( OR=7.824, 95% CI: 2.824-21.673) were independent risk factors for PB caused by MP infection (all P<0.05). The cut-off values of age, percentage of neutrophils, CRP, and DD were 64 months, 0.70, 35 mg/L, and 2 000 μg/L. Conclusions:Children with PB caused by MP often develop in older and allergic children who have stronger inflammatory reactions, immune disorders, and hyperfibrinolysis.