Expression of IL4 (VNTR intron 3) and IL10 (-627) genes polymorphisms in childhood immune thrombocytopenic purpura

IL-4Rα (rs1801275) A>G polymorphism in Egyptian immune thrombocytopenia (ITP) patients: a single center experience

INTRODUCTION

Chronic immune thrombocytopenia (cITP) is characterized by dysregulation of the immune response. Until recently, the role of Th2-related cytokine gene polymorphisms was unclear. Interleukin 4 (IL-4) exerts its functions by binding to three types of IL-4 receptor (IL-4R) complexes. We aimed to explore the potential association between the gene polymorphism of IL-4Rα and cITP.

METHODS

We investigated the clinical impact of the IL-4Rα (rs1801275) A>G single nucleotide polymorphism (SNP) using the polymerase chain reaction (PCR) followed by the restriction fragment length polymorphism (RFLP) method in 82 cITP patients and 60 healthy controls (HCs).

RESULTS

The IL-4Rα (rs1801275) A>G polymorphism analysis showed the mutant GG genotype was significantly higher in control females (p = 0.033). The wild AA genotype had a higher bleeding score (p = 0.02) in the adulthood onset group. Furthermore, the wild AA genotype in the cITP childhood onset group was significantly associated with the disease severity, as well as the response to treatment (p = 0.040).

CONCLUSION

The mutant G allele is protective against the susceptibility to cITP in the Egyptian females. The IL-4Rα (rs1801275) A>G polymorphism may affect the clinical severity of cITP and treatment response in the Egyptian population.

CD4+ T cell phenotypes in the pathogenesis of immune thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by low platelet counts due to enhanced platelet clearance and compromised production. Traditionally, ITP was regarded a B cell mediated disorder as anti-platelet antibodies are detected in most patients. The very nature of self-antigens, evident processes of isotype switching and the affinity maturation of anti-platelet antibodies indicate that B cells in order to mount anti-platelet immune response require assistance of auto-reactive CD4⁺ T cells. For a long time, ITP pathogenesis has been exclusively reviewed through the prism of the disturbed balance between Th1 and Th2 subsets of CD4⁺ T cells, however, more recently new subsets of these cells have been described including Th17, Th9, Th22, T follicular helper and regulatory T cells. In this paper, we review the current understanding of the role and immunological mechanisms by which CD4⁺ T cells contribute to the pathogenesis of ITP.

Polymorphism of the IL-1β, TNF, IL-1RA and IL-4 Cytokine Genes Significantly Increases the Risk of Preterm Birth

Preterm birth is not only medical, but also a social problem. The global goal of medicine is prevention of preterm labor and identification of risk factors leading to preterm birth. The objective of our study was to find the association between polymorphic markers in the cytokine IL-1β, TNF-α, IL-1Ra, and IL-4 genes and development of preterm labor. The prospective study was conducted in 108 pregnant women with the risk of preterm birth. The main group consisted of 66 women whose pregnancy ended with preterm delivery despite the ongoing therapy. The comparison group included 42 women with the full-term delivery. The dominant T allele of the cytokine IL-1β gene polymorphism rs1143634 (3953C→T) was 7.6 times more common in women with preterm delivery vs. the comparison group (36.4 and 4.8%, respectively; RR, 1.802; 95% CI, 1.420-2.288; p < 0.05); its homozygous form was detected only in women with preterm delivery at the very early gestation age (less than 26 weeks). The dominant proinflammatory allele 2R of the IL-1 receptor antagonist gene (IL-1Ra) was 1.5 times more common in women with preterm delivery than in the comparison group (63.6 and 42.8%, respectively; RR, 1.400; 95% CI, 1.009-1.943; p < 0.05), which makes the 2R allele the risk factor for preterm birth. The 2R/2R and 2R/4R genotypes led to a very early and early preterm delivery, respectively. The combination of three or four proinflammatory genotypes was detected only in women with a very early preterm delivery, which confirms that the combination of several proinflammatory genotypes is an extremely unfavorable factor for the full-term pregnancy. Identification of genetic polymorphisms in the interleukin genes at the periconceptional stage will help to prevent the risk of preterm delivery, which will reduce the incidence of preterm births, as well as perinatal morbidity and mortality.

IL-1RN VNTR, IL-2(-330), and IL-4 VNTR gene polymorphisms in patients with chronic rhinosinusitis with sinonasal polyposis

Background/aim

Sinonasal polyposis is a complex chronic disease displaying contributions from multiple genetic and environmental factors. In this study, we analyzed possible genetic factors that increase susceptibility to this widespread inflammatory disease.

Materials and methods

A total of 176 adult patients, including 78 patients with sinonasal polyposis and 98 healthy controls, were analyzed for IL-1RN VNTR, IL-2(-330), and IL-4 VNTR gene polymorphisms using polymerase chain reaction and enzyme restriction.

Results

IL-1RN and IL-4 VNTR polymorphisms were notably associated with sinonasal polyposis (P = 0.0001 and P = 0.036, respectively); however, regarding the IL-2(-330) gene polymorphism, no significant difference was shown between the patient and control groups (P = 0.235).

Conclusions

Our study indicates that the RN2 allele of IL-1RN and the RP1 allele of IL-4 might be risk factors for developing sinonasal polyposis.

A CARD9 single-nucleotide polymorphism rs4077515 is associated with reduced susceptibility to and severity of primary immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease characterized by a low platelet count and consequent increased risk of bleeding. The etiology underlying this condition remains poorly understood. The aim of this study is to evaluate the association of a single nucleotide polymorphism (SNP) rs4077515 in the caspase recruitment domain-containing protein 9 (CARD9) gene with the pathogenesis and therapy of ITP. Two hundred ninety-four patients with ITP and 324 age-matched healthy participants were recruited in this case-control study. Genotyping of CARD9 rs4077515 polymorphism was performed by Sanger sequencing. Our results revealed that a polymorphism rs4077515 in CARD9 gene is associated with decreased risk of susceptibility to and severity of ITP (susceptibility: codominant, AA vs. GG, OR = 0.175, 95% CI = 0.054-0.776, p = 0.001; recessive, GG + AG vs. AA, OR = 6.183, 95% CI = 2.287-16.715, p < 0.001; severity: allele, A vs. G, OR = 0.685, 95% CI = 0.476-0.985, p = 0.041; codominant, AG vs. GG, OR = 0.571, 95% CI = 0.350-0.931, p = 0.025; dominant, AA + AG vs. GG, OR = 0.558, 95% CI = 0.343-0.907, p = 0.019). The existence of the allele A, the mutant AA genotype and the heterozygous AG genotype of CARD9 rs4077515, plays a protective role in ITP. However, CARD9 rs4077515 polymorphism had no effect on corticosteroid sensitivity or refractoriness of ITP.

Relationship between the IL-10 (-1082 A/G) polymorphism and the risk of immune/idiopathic thrombocytopenic purpura: A meta-analysis

BACKGROUND

The association of the IL-10 gene polymorphism with immune thrombocytopenic purpura (ITP, also called idiopathic thrombocytopenic purpura) susceptibility has been investigated in several studies; however, the association remains controversial. The present meta-analysis aimed to determine whether the IL-10 (-1082) polymorphism is associated with an increased risk of ITP.

MATERIALS AND METHODS

Eligible articles were searched in EMBASE, PubMed, CNKI, WanFang, and HuGE Navigator, without any restriction of publication language. The odds ratios (ORs) and 95% confidence intervals (CIs) were used to identify any potential associations between the IL-10 (-1082 A/G) polymorphism and the risk of ITP.

RESULTS

This meta-analysis included six eligible studies with 384 cases and 409 controls. There was no significant association between the IL-10 (-1082) polymorphism and the risk of ITP in any of the genetic models. Three subgroups were stratified according to population ethnicity, disease subtype (acute or chronic), and age (child or adult). No statistically significant differences were observed in age and ethnicity between cases and controls. However, subtype analysis indicated significant associations for acute ITP in the allele model (OR = 1.76, 95% CI = [1.07; 2,89]), the recessive model (OR = 2.66, 95% CI = [1.17; 6.07]), and the homozygote model (OR = 2.65, 95% CI = [1.07; 6.55]).

CONCLUSIONS

There is scarce evidence to confirm an association between the IL-10 (-1082) polymorphism and the risk of ITP. However, the IL-10 (-1082) polymorphism might be associated with the risk of acute ITP. Additional large, well-designed epidemiological studies should be performed to draw definitive conclusions.

Association between gene polymorphisms and clinical features in idiopathic thrombocytopenic purpura patients

: Immune thrombocytopenic purpura (ITP) is an autoimmune disease in which increased platelet destruction and thrombocytopenia are diagnostic features. In fact, the exact pathogenesis of this disease is still unknown, but genetic changes can be a potential factor in the development of ITP. In this study, the relationship between polymorphisms with platelet destruction has been studied, which leads to decreased platelet count. Relevant literature was identified by a PubMed search (2000-2016) of English language papers using the terms 'ITP', 'polymorphism,' and 'immune system'. The majority of genetic changes (polymorphisms) occur in immune system genes, including interferon (IFN)-γ gene. These changes lead to the dysfunction of immune system and production of pathogenic antibodies against platelet surface glycoproteins such as glycoprotein IIb/IIIa, which eventually result in the destruction of platelets and increasing disease severity. In addition, IFN-γ as well as factors and cytokines involved in megakaryopoiesis, including stem cell factor and interleukin-3 (IL-3), leads to the differentiation of megakaryocytes and platelet release. Considering the fact that IFN-γ is a factor of inflammation and thrombocytopenia, coexistence of this cytokine with thrombopoietin, stem cell factor, and IL-3 results in megakaryocytes differentiation and platelet production, which can be effective to reduce disease severity and increase the platelet counts.

The cytokine polymorphisms affecting Th1/Th2 increase the susceptibility to, and severity of, chronic ITP

BACKGROUND

T-helper cell type 1 (Th1) polarization in chronic immune thrombocytopenia (cITP) has been reported at the protein and mRNA levels. We evaluated the impact of Th1/Th2 cytokine and cytokine receptor functional polymorphisms on both susceptibility to, and severity of, cITP. We analysed IFN-γ + 874 T/A, IFN-γR -611G/A, IL-4 -590C/T, and IL-4Rα Q576R polymorphisms in 126 cITP patients (male/female: 34/92; median age: 47.7 years) and 202 healthy control donors. Genotyping was determined by PCR and direct sequencing. The Th1/Th2 ratio was detected in peripheral blood mononuclear cells via flow cytometry.

RESULTS

cITP patients had a higher frequency of the IL-4Rα 576 non-QQ genotype compared to healthy subjects (P = 0.04). cITP patients with the IFN-γ +874 non-AA genotype (high expression type) showed more severe thrombocytopenia than those with the AA genotype (P < 0.05). cITP patients had a significantly higher Th1/Th2 ratio than control patients (P < 0.01); this ratio was inversely correlated with platelet counts. Furthermore, patients with both IFN-γ +874 non-AA genotype (high expression type) and IFN-γR -611 non-AA genotype (high-function type) had a significantly higher Th1/Th2 ratio (P < 0.05).

CONCLUSIONS

The cytokine polymorphisms affecting Th1/Th2 increase the susceptibility to, and severity of, chronic ITP.

The Centenary of Immune Thrombocytopenia - Part 1: Revising Nomenclature and Pathogenesis

The natural history of the immune thrombocytopenia (ITP) is interesting and intriguing because it traces different steps underlying autoimmune diseases. The review points out the main steps that have accompanied the stages of its history and the consequential changes related to its terminology. ITP is an autoimmune disease resulting from platelet antibody-mediated destruction and impaired megakaryocyte and platelet production. However, research advances highlight that a complex dysregulation of the immune system is involved in the pathogenesis of this condition. The review examines the role of the multiple immune components involved in the autoimmunity process, focusing on the more recent mechanisms, which could be new promising therapeutic targets for ITP patients.