Genetic markers of children asthma: predisposition to disease course variants

Asthma is a heterogeneous and often difficult to treat condition that results in a disproportionate cost to healthcare systems. Children with severe asthma are at increased risk for adverse outcomes including medication-related side effects, life-threatening exacerbations, and impaired quality of life. An important therapeutic focus is to achieve disease control, which is supposed to involve a personalized approach to treatment of asthma of any severity. Asthma is a multifactorial disease with a significant genetic determinant, however, the inheritance of asthma has not been fully elucidated. Polymorphic genes of inflammatory mediators, including cytokines, play an important role in developing various disease forms. In the current study, large-scale original data on the prevalence of cytokine gene genotypes (IL2, IL4, IL5, IL6, IL10, IL12, IL13, IL17A, IL31, IL33, IFNG, TNFA) among Russian children with asthma in Krasnoyarsk region have been obtained. Genotyping was carried out using real-time PCR. We identified markers predisposing to the development of different variants of the course of childhood asthma: the CT genotype and T allele of IL4 rs2243250 are associated with asthma (p < 0.05), especially in mild asthma and in controlled asthma. The TT genotype and allele T of IL13 rs1800925 are associated with severe and uncontrolled asthma (p < 0.05). The AA genotype of IL17A rs2275913, the TT genotype of IFNG rs2069705 and allelic A variants of TNFA rs1800629 are associated with mild asthma, and the TT genotype of IFNG rs2069705 is additionally associated with controlled asthma. The results obtained will supplement information on the prevalence of polymorphic variants of the cytokine genes in the Russian population and in asthma patients with different disease courses, which is likely to be used in order to shape a plan for Public Health Authority to prevent the development of severe uncontrolled asthma and to optimize personalized therapy.

Impact of cytokines genes polymorphisms and their serum levels on childhood asthma in Egyptian population

BACKGROUND

Asthma is chronic immune-mediated airway inflammation, and it is affected by a complex network of interacting cytokines. To date, the exact role of each cytokine and its genetic polymorphisms in childhood asthma development and its severity has remained poorly understood. The purpose of this study was to explore potential roles of four cytokine genes polymorphism and serum levels l [(T helper-2 (Th2) cytokine); Interleukin-4 (IL-4) 590, (Th3 cytokine); and transforming growth factor β1 (TGF-β1) 509T; (Th17) including tumor necrosis factor-alpha (TNF-α), and IL17A rs8193036] in childhood asthma risk and control in Egyptian children, for the 1st time.

MATERIALS AND METHODS

This case-control study included two children subgroups; Group1 included 216 non-asthmatic controls and (Group 2) 216 cases diagnosed with asthma (clinically and spirometry-based) were classified as controlled, partly controlled, and uncontrolled. Polymorphisms of TGF-β1-509, IL-4 590, and TNF-α-308 genes were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). IL-17 was genotyped using tetra-primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Serum cytokines levels were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum total IgE, TGF-β1, IL4, TNF-α, and IL17A levels were significantly higher in asthmatic compared to controls. Also, significant increases in serum total IgE, IL-4, TGF-β1, and TNF-α levels are combined with poor asthma control, while no significant IL17A changes. There were significant changes of IL-4-590, TNF-α-308, and IL17A genotypes and allele distributions between asthmatic and controls groups as well as different asthma control levels; while no impact of TGF-β1 SNP on asthma risk and control level. Four cytokines SNPs affected their serum levels among asthmatic patients.

CONCLUSION

There are impacts of cytokine gene polymorphisms (IL-4-590, TNF-α-308, and IL17A); but not TGF-β1 on asthma susceptibility and poor asthma control in Egyptian children.

IL-17 polymorphisms and asthma risk: a meta-analysis of 11 single nucleotide polymorphisms

OBJECTIVE

There has been significant interest in the association between asthma and the polymorphisms of IL-17A and IL-17F for a period of time. This work aims to present a clearer relationship between asthma and the polymorphisms of IL-17A and IL-17F.

METHOD

Searches were performed in Medline, EMBASE, and the Chinese National Knowledge Infrastructure (CNKI) databases. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationship between polymorphisms of IL-17A and IL-17F and asthma.

RESULTS

Nine studies comprising 3650 asthmatics and 3370 controls were included in this meta-analysis for all single nucleotide polymorphisms (SNPs) (2-6 per SNP). Our study examined the polymorphisms of IL-17F rs1889570 (C/T) (CC versus TT: OR = 0.55, 95%CI = 0.41-0.75; CT versus TT: OR = 0.54, 95%CI = 0.40-0.72; CC/CT versus TT: OR = 0.55, 95%CI = 0.42-0.72; CC versus CT/TT, OR = 1.83, 95%CI = 1.39-2.41), IL-17A rs4711998(A/G) (AA/AG versus GG: OR = 0.67, 95%CI = 0.46-0.98), and IL-17A rs3819024(A/G) (AA versus GG: OR = 1.77, 95%CI = 1.39-2.25) and found they were significantly related to the risk of asthma.

CONCLUSION

Our systematic review showed that IL-17F rs1889570(C/T), IL-17A rs4711998(A/G) and IL-17A rs3819024(A/G) may be potential risk factors for asthma susceptibility.