Household mold exposure interacts with inflammation-related genetic variants on childhood asthma: a case-control study.

BACKGROUND: A number of studies have examined the association between mold exposure and childhood asthma. However, the conclusions were inconsistent, which might be partly attributable to the lack of consideration of gene function, especially the key genes affecting the pathogenesis of childhood asthma. Research on the interactions between genes and mold exposure on childhood asthma is still very limited. We therefore examined whether there is an interaction between inflammation-related genes and mold exposure on childhood asthma. METHODS: A case-control study with 645 asthmatic children and 910 non-asthmatic children aged 3-12 years old was conducted. Eight single nucleotide polymorphisms (SNPs) in inflammation-related genes were genotyped using MassARRAY assay. Mold exposure was defined as self-reported visible mold on the walls. Associations between visible mold exposure, SNPs and childhood asthma were evaluated using logistic regression models. In addition, crossover analyses were used to estimate the gene-environment interactions on childhood asthma on an additive scale. RESULTS: After excluding children without information on visible mold exposure or SNPs, 608 asthmatic and 839 non-asthmatic children were included in the analyses. Visible mold exposure was reported in 151 asthmatic (24.8%) and 119 non-asthmatic children (14.2%) (aOR 2.19, 95% CI 1.62-2.97). The rs7216389 SNP in gasdermin B gene (GSDMB) increased the risk of childhood asthma with each C to T substitution in a dose-dependent pattern (additive model, aOR 1.32, 95% CI 1.11-1.57). Children carrying the rs7216389 T allele and exposed to visible mold dramatically increased the risk of childhood asthma (aOR 3.21; 95% CI 1.77-5.99). The attributable proportion due to the interaction (AP: 0.47, 95% CI 0.03-0.90) and the relative excess risk due to the interaction (RERI: 1.49, 95% CI 0-2.99) were statistically significant. CONCLUSIONS: In the present study, there was a significant additive interaction between visible mold exposure and rs7216389 SNP on childhood asthma. Future studies need to consider the gene-environment interactions when exploring the risk factors of childhood asthma.

Atopy: a risk factor of refractory mycoplasma pneumoniae pneumonia?

OBJECTIVE: To investigate the relationship of pathogen DNA copies with clinic and laboratory features among children with Mycoplasma pneumoniae (MP) pneumonia. METHODS: A total of 95 enrolled children with MP pneumonia were assigned into the high-MP-load group (>106 /mL) and the low-MP-load group (≤106 /mL) according to MP-DNA copies in bronchoalveolar lavage fluid (BALF). Clinical characteristics and any allergy history were collected. Aeroallergens and food allergens were detected with a skin test. Serum IgE and eosinophil cationic protein (ECP) were assessed using enzyme immunoassay. BALF levels of IL-4, IFN-γ, IL-8 and TNF-α were assessed by ELISA. RESULTS: Compared with the low-MP-load group, 72.7% in the high-MP-load group developed refractory MP pneumonia who failed to respond to at least 1-week treatment with macrolides (72.7% vs 41.9%, P = 0.005). More children in the high-load group than those in the low-load group presented with extrapulmonary manifestations, lung consolidation, pleural effusion and atopic conditions including any allergy history, positive findings of aeroallergen test and increased serum IgE and ECP (P < 0.05). A significant higher BALF IL-4 level was seen in the high-load group versus the low-load group (23.00 ± 11.24 vs 14.68 ± 7.12; pg/mL; P < 0.01). There were no significant differences in BALF levels of IFN-γ, IL-8 and TNF-α between the two groups (P > 0.05). CONCLUSION: Atopy may be a risk factor for the presence and severity of refractory MP pneumonia due to the high pathogen load in airway.

Good response to infliximab in rheumatoid arthritis following failure of interleukin-1 receptor antagonist.

AIM: To evaluate the efficacy of tumor necrosis factor inhibitor infliximab in patients with rheumatoid arthritis (RA) who were disease-resistant to recombinant human interleukin-1 receptor antagonist (IL-1Ra). METHODS: A total of 104 patients with active RA despite methotrexate (MTX) treatment were enrolled in the open trial. Among them, 27 IL-1Ra nonresponders 'Switchers' and 51 biologic-naive patients 'Naivers' received an infusion of 3 mg/kg infliximab at weeks 0, 2, 6 and 14, combined with concurrent MTX therapy, while the other 26 patients who had never received any biologics 'Controls' continued MTX monotherapy. Clinical outcomes and safety were assessed at weeks 0, 2 and every 4 weeks thereafter for 18 weeks with the American College of Rheumatology (ACR) core set criteria, the Disease Activity Score in 28 joints, and records of adverse events (AEs) and abnormal laboratory findings. RESULTS: At week 18, an ACR20 response was achieved in 56% of Switchers and 61% of Naivers, compared with 23% of Controls (P = 0.0013 and 0.0126, respectively). Compared with Controls, both Switchers and Naivers achieved a significant improvement in tender-joint count, swollen-joint count, patient's assessment of pain, patient's and physician's global assessment of disease activity, erythrocyte sedimentation rate and C-reactive protein. Switchers even achieved a greater benefit from health assessment questionnaire (HAQ) scores than Naivers. Infliximab was well tolerated, with a similar incidence of AEs across all study groups. CONCLUSION: Switching from IL-1Ra to infliximab is effective in improving disease activity and maintaining joint function.