Relationship Between Atopy And Mycoplasma Pneumoniae Infection In Systemic Juvenile Idiopathic Arthritis Children And Its Influence On Prognosis

Objective: To investigate the relationship between atopy and Mycoplasma pneumoniae (MP) infection in systemic juvenile idiopathic arthritis (SoJIA) children and its impact on the prognosis of the disease. Methods: The clinical data of 39 SoJIA children were collected including atopy, MP infection and course characteristics; RT-PCR method was performed to detect expression levels of IL-17, Foxp3, MDR-1 and MRP-1 mRNA in peripheral blood mononuclear cells; Flow cytometry was applied to analyze peripheral blood lymphocytes ratio discharging daunorubicin. Results: MP infection rate is significantly higher in SoJIA children with atopy (X-2=11.7986, p=0.0006); non-monophasic disease ratio in MP+Atopy+ group, MP+Atopy- group and MP-Atopy+ group were significantly higher than MP-Atopy- group (X-2=14.4026, p=0.0024). The mRNA expression levels of IL-17 and MDR-1 in Atopy+ group and MP+ group were significantly higher than MP-Atopy- group, Atopy- group, MP- group and the normal control group, moreover, levels of IL-17 and MDR-1 in MP+Atopy+ group were significantly higher than MP-Atopy- group and normal control group (F=5.1016, P=0.0001; F=16.4463, P=0.0000; respectively). In contrast, Foxp3 mRNA expression in Atopy+ group, MP+ group were significantly lower thanMP-Atopy- group, MP- group, Atopy- group and the normal control group, also expression of Foxp3 in MP+Atopy+ group was significantly lower than MP-Atopy- group and the normal control group (F=11.8421, P=0.0000). The ratio of lymphocytes capable of discharging daunorubicin in MP+Atopy+ group is significantly higher than the MP-Atopy-group (t=2.5399, p=0.0164). Conclusion; There are close relations amongSoJIA children complicated with atopy and MP infection and Th17/Treg cells imbalance. SoJIA children merged atopy or MP infection may promote Th17 cell proliferation and increase IL-17 expression resulting in the aggravation of an autoimmune reaction, subsequently induce SoJIA children resistance by upregulating the expression of the multidrug resistance gene MDR-1, maybe these two aspects eventually lead to SoJIA children with poor prognosis.