Investigation of TNF-alpha, TGF-beta 1, IL-10, IL-6, IFN-gamma, MBL, GPIA, and IL1A gene polymorphisms in patients with idiopathic thrombocytopenic purpura

TNFα-308G>A Polymorphism and Susceptibility to Immune Thrombocytopenia Purpura (ITP): Evidence From a Systematic Review and Meta-analysis

BACKGROUND

Relation between the emergence of ITP and the presence of TNFα 308G/A polymorphism in the involved individuals has been studied by previous researchers in different ethnicity, but a definite result was not gained. So, this meta-analysis was performed to find an absolute answer to the question whether TNF-α-308G/A polymorphism is a susceptibility factor for ITP or not?

METHODS

Electronic databases including PubMed, Google scholar, and Science Direct were searched and case control studies compatible to the defined inclusion criteria were selected; their references were also evaluated manually. Pooled OR with 95 % confidence intervals (CIs) as a strength of association between TNF-α-308G/A polymorphism and risk of ITP were calculated using a random-effect model. Funnel plot and Egger's linear regression test were conducted to examine the risk of publication bias.

RESULTS

Totally, 16 eligible articles were found involving 1470 ITP cases and 2324 healthy controls. The Meta-results revealed that TNFα 308G/A polymorphism is associated with increased risk of ITP under the genetic models of recessive (OR: 1.54, 95 % CI: 1.03-2.29), dominant (OR: 2.29, 95 % CI: 1.44-3.64), and the heterozygote (OR: 2.46, 95 % CI:1.49-4.6). Subgroup analysis suggested a remarkable role for this SNP as a risk factor in the Caucasian ethnicity and the chronic subtype.

CONCLUSION

TNFα 308G/A polymorphism can be an ITP susceptibility factor in the Caucasian population and the chronic subtype. Although more studies in large scale are needed for clinical decision but this finding can be used in the clinical trials to prevent the ITP consequences in the involved individuals.

The many facets of immune-mediated thrombocytopenia: Principles of immunobiology and immunotherapy

Immune thrombocytopenia (ITP) is a rare autoimmune condition, due to peripheral platelet destruction through antibody-dependent cellular phagocytosis, complement-dependent cytotoxicity, cytotoxic T lymphocyte-mediated cytotoxicity, and megakaryopoiesis alteration. This condition may be idiopathic or triggered by drugs, vaccines, infections, cancers, autoimmune disorders and systemic diseases. Recent advances in our understanding of ITP immunobiology support the idea that other forms of thrombocytopenia, for instance, occurring after immunotherapy or cellular therapies, may share a common pathophysiology with possible therapeutic implications. If a decent pipeline of old and new agents is currently deployed for classical ITP, in other more complex immune-mediated thrombocytopenic disorders, clinical management is less harmonized and would deserve further prospective investigations. Here, we seek to provide a fresh overview of pathophysiology and current therapeutical algorithms for adult patients affected by this disorder with specific insights into poorly codified scenarios, including refractory ITP and post-immunotherapy/cellular therapy immune-mediated thrombocytopenia.

Frequency of toll-like receptor 4 variants and association with treatment response in children with primary immune thrombocytopenia

OBJECTIVES

To investigate the frequency of toll-like receptor 4 (TLR4) variants c.896A>G (p.Asp299Gly) and c.1196C>T (p.Thr399Ile) among Egyptian children with primary immune thrombocytopenia (pITP), and their association with disease course and response to treatment.

METHODS

A case-control study that included 80 children with pITP and 50 age- and sex-matched healthy controls. TLR4 c.896A>G and c.1196C>T variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism. Patients were classified according to their response to treatment after 3 months as responders and nonresponders.

RESULTS

Compared with controls, children with pITP had significantly higher minor allele frequencies of TLR4 p.Asp299Gly (16.25% vs. 6%, odds ratio [OR] 3.04, 95% confidence interval [CI]: 1.16-9.36, p = .014) and p.Thr399Ile (20% vs. 4%, OR 6, 95% CI: 2.02-24.01, p < .001). The presence of p.Asp299Gly variant was significantly associated with chronic ITP (OR 7.78, 95% CI: 2.04-35.69, p < .001) and non-response to therapy with steroid (OR 11.67, 95% CI: 1.32-104.08, p = .012), but not thrombopoietin-receptor agonist (OR 1.67, 95% CI: 0.35-8.19, p = .464). Likewise, having p.Thr399Ile variant was significantly associated with chronic ITP (OR 5.14, 95% CI: 1.6-17.4, p = .002) and non-response to therapy with steroid (OR 6.1, 95% CI: 1.01-49.06, p = .046) but not thrombopoietin-receptor agonist (OR 1.57, 95% CI: 0.33-7.58, p = .515).

CONCLUSION

The presence of TLR4 p.Asp299Gly or p.Thr399Ile variant may be associated with ITP predisposition, chronicity, and non-response to upfront steroid therapy. These findings enhance our understanding of the complex pathophysiology of pITP with potentially important clinical implications.

Cytokines Single Nucleotide Polymorphisms (SNPs) Association With Myasthenia Gravis (MG) In Algerian Patients: A Case-Control Study On A Small Group

ABSTRACT

Myasthenia gravis (MG) is an autoimmune disease of multifactorial etiology in which genetic factors and cytokines seem to play an important role. The aim of this study was to investigate potential associations of cytokines single nucleotide polymorphisms (SNPs) and MG in Algerian patients. We performed a case-control study that included 27 patients and 74 healthy subjects. Cytokines SNPs genotyping was performed by the polymerase chain reaction sequence-specific primers (PCR-SSP) method. Our results showed that the TNF-α -308G/A (P < 0.005) and TGF-β1 +869T/T (P < 0.05) genotypes were more frequent among patients with MG compared with healthy individuals, whereas TNF-α -308G/G (P < 0.0001), TGF-β1 +869T/C (P < 0.05), and IFN-γ +874A/A (P < 0.05) were less frequent. Our results also showed that IL-10 and IL-6 SNPs did not show any significant difference in distribution between MG patients and healthy individuals. Our observations support the hypothesis that implicates genetic variants of certain cytokines in MG. However, ours results should be replicated with a larger sample size. In addition, the precise underlying processes remain to be clarified.

HIGHLIGHTS

TNF-α -308G/A and TGF-β1 +869T/C genotypes predispose to MG.IFN-γ +874A/A genotype protects against MG.IL-6 -174C/G SNP is not associated with MG.

Changes in Adenosine Deaminase Activity and Endothelial Dysfunction after Mild Coronavirus Disease-2019

Endothelial cells are a preferential target for SARS-CoV-2 infection. Previously, we have reported that vascular adenosine deaminase 1 (ADA1) may serve as a biomarker of endothelial activation and vascular inflammation, while ADA2 plays a critical role in monocyte and macrophage function. In this study, we investigated the activities of circulating ADA isoenzymes in patients 8 weeks after mild COVID-19 and related them to the parameters of inflammation and microvascular/endothelial function. Post-COVID patients revealed microvascular dysfunction associated with the changes in circulating parameters of endothelial dysfunction and inflammatory activation. Interestingly, serum total ADA and ADA2 activities were diminished in post-COVID patients, while ADA1 remained unchanged in comparison to healthy controls without a prior diagnosis of SARS-CoV-2 infection. While serum ADA1 activity tended to positively correspond with the parameters of endothelial activation and inflammation, sICAM-1 and TNFα, serum ADA2 activity correlated with IL-10. Simultaneously, post-COVID patients had lower circulating levels of ADA1-anchoring protein, CD26, that may serve as an alternative receptor for virus binding. This suggests that after the infection CD26 is rather maintained in cell-attached form, enabling ADA1 complexing. This study points to the possible role of ADA isoenzymes in cardiovascular complications after mild COVID-19.

Novel Biomarkers for Diagnosis and Monitoring of Immune Thrombocytopenia

Lower-than-normal platelet counts are a hallmark of the acquired autoimmune illness known as immune thrombocytopenia, which can affect both adults and children. Immune thrombocytopenia patients' care has evolved significantly in recent years, but the disease's diagnosis has not, and it is still only clinically achievable with the elimination of other causes of thrombocytopenia. The lack of a valid biomarker or gold-standard diagnostic test, despite ongoing efforts to find one, adds to the high rate of disease misdiagnosis. However, in recent years, several studies have helped to elucidate a number of features of the disease's etiology, highlighting how the platelet loss is not only caused by an increase in peripheral platelet destruction but also involves a number of humoral and cellular immune system effectors. This made it possible to identify the role of immune-activating substances such cytokines and chemokines, complement, non-coding genetic material, the microbiome, and gene mutations. Furthermore, platelet and megakaryocyte immaturity indices have been emphasized as new disease markers, and prognostic signs and responses to particular types of therapy have been suggested. Our review's goal was to compile information from the literature on novel immune thrombocytopenia biomarkers, markers that will help us improve the management of these patients.

Scoping Review on Epigenetic Mechanisms in Primary Immune Thrombocytopenia

Immune Thrombocytopenia (ITP) is an autoimmune blood disorder that involves multiple pathways responsible for the homeostasis of the immune system. Numerous pieces of literature have proposed the potential of immune-related genes as diagnostic and prognostic biomarkers, which mostly implicate the role of B cells and T cells in the pathogenesis of ITP. However, a more in-depth understanding is required of how these immune-related genes are regulated. Thus, this scoping review aims to collate evidence and further elucidate each possible epigenetics mechanism in the regulation of immunological pathways pertinent to the pathogenesis of ITP. This encompasses DNA methylation, histone modification, and non-coding RNA. A total of 41 studies were scrutinized to further clarify how each of the epigenetics mechanisms is related to the pathogenesis of ITP. Identifying epigenetics mechanisms will provide a new paradigm that may assist in the diagnosis and treatment of immune thrombocytopenia.

Combined tumor necrosis factor-α (-308 G/A) and tumor necrosis factor-β (+ 252 A/G) nucleotide polymorphisms and chronicity in Egyptian children with immune thrombocytopenia

BACKGROUND

Primary immune thrombocytopenia (ITP) is a common autoimmune disorder. Secretion of TNF-α, TNF-β and IFN-γ plays a major role in the pathogenesis of ITP.

OBJECTIVE

This cross-sectional study aimed to detect TNF-α (-308 G/A) and TNF-β (+ 252 A/G) gene polymorphism in a cohort of Egyptian children with chronic ITP (cITP) to clarify their possible association with progression to chronic disease.

METHODS

The study included 80 Egyptian cITP patients and 100 unrelated age- and sex-matched controls. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Patients with TNF-α homozygous (A/A) genotype had significantly higher mean age, longer disease duration and lower platelet counts (p values 0.005, 0.024 and 0.008, respectively). TNF-α wild (G/G) genotype was significantly more frequent among responders (p = 0.049). Complete response was more frequent among wild (A/A) TNF-β genotype patients (p = 0.011), and platelet count was significantly lower among homozygous (G/G) genotype (p = 0.018) patients. Combined polymorphisms were strongly associated with susceptibility to chronic ITP.

CONCLUSION

Homozygosity in either gene might contribute to a worse course of disease, increased severity and poor response to therapy. Patients expressing combined polymorphisms are more prone to progression to chronic disease, severe thrombocytopenia and longer disease duration.

Role of IL-10 and IL-22 cytokines in patients with primary immune thrombocytopenia and their clinical significance

BACKGROUND

Immune thrombocytopenia purpura (ITP) is an autoimmune disease that leads to accelerated platelet clearance. The objective of this study was to examine the clinical role of cytokines in ITP patients and to correlate them with disease stages.

MATERIALS AND METHODS

A total of 110 ITP patients were enrolled, including 55 with active ITP, 55 with remission ITP, and 55 with healthy controls. The enzyme-linked immunosorbent assay technique was used to examine IL-10 and IL-22 serum levels in all subjects. Real-time quantitative PCR was used to assess the mRNA expression of IL-10 and IL-22 in PBMC. The clinical significance of both cytokines was assessed using ROC analysis.

RESULTS

IL-10 serum levels in active ITP patients were significantly lower than in control and remission ITP subjects (p < 0.05). IL-22 serum levels were elevated in active ITP patients compared to the control and remission group (p < 0.05). mRNA expressions of IL-10 and IL-22 in active ITP patients were also having a significant difference from than control and remission ITP group (p < 0.05). ROC analysis showed that IL-10 and IL-22 can differentiate the ITP patients from controls. A positive correlation between serum IL-10 and PBMC IL-10 with statistical significance was observed. Similarly, the serum IL-22 and PBMC IL-22 were correlated positively with statistical significance.

CONCLUSION

IL-10 and IL-22 seem to predict the clinical course of ITP, as a significant imbalance of these cytokines was detected in active ITP patients.

Association between ATP binding cassette gene member 1 polymorphism and glucocorticoid response in children with immune thrombocytopenia

ATP binding Cassette gene member 1 (ABCB1) polymorphism has been incriminated in susceptibility to many malignant, infectious and autoimmune diseases. Recently, it was reported that ABCB1 polymorphisms might have a link to disease progression as well as response to therapy. We aimed to study the association between ABCB1 gene polymorphism and glucocorticoid response in children with newly diagnosed immune thrombocytopenia (ITP). A case control study was conducted on 90 newly diagnosed children with ITP and 90 healthy controls over a period of 1 year. ABCB1 (C3435T) polymorphism was determined by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) in patients and controls. There was no significant difference between patients and controls as regards to frequency of different ABCB1 genotypes (CC, CT, and TT genotypes were 44.4%, 36.7%, and 18.9% respectively in patients and 48.9%, 38.9%, and 12.2% respectively in controls, P value = 0.18). 80% of patients who received steroids alone or steroids in combination with intravenous immunoglobulin showed complete recovery. There was highly significant relationship between ABCB1 genotypes and response to steroids where 55 % of responders had CC (wild) genotype while 40 % of nonresponders had TT (mutant) genotype. We concluded that ABCB1 gene polymorphism may contribute to the response to steroids in Egyptian children with ITP where patients with homozygous CC genotype responded better to steroids than patients with homozygous TT genotype. These results may help us choose the appropriate initial treatment in these children.

Single Nucleotide Polymorphisms of the HIF1A Gene are Associated With Sensitivity of Glucocorticoid Treatment in Pediatric ITP Patients

BACKGROUND

Hypoxia-inducible factor-1α (HIF-1α) plays a crucial role in both innate and adaptive immunity. Emerging evidence indicates that HIF-1α is associated with the inflammation and pathologic activities of autoimmune diseases, suggesting that HIF1α may be involved in immune dysregulation in patients with immune thrombocytopenia (ITP). The purpose of this study was to evaluate whether single nucleotide polymorphisms (SNPs) of the HIF1A gene are associated with susceptibility to ITP and its clinical prognosis including incidence of chronic ITP and glucocorticoid sensitivity.

MATERIALS AND METHODS

This study involved 197 Chinese ITP pediatric patients (discovery cohort) and 220 healthy controls. The Sequenom MassArray system (Sequenom, San Diego, CA) was used to detect 3 SNPs genotypes in the HIF1A gene: rs11549465, rs1957757, and rs2057482. We also used another ITP cohort (N=127) to validate the significant results of SNPs found in the discovery cohort.

RESULTS

The frequencies of the three SNPs did not show any significant differences between the ITP and healthy control groups. The CT genotype at rs11549465 was significantly higher in ITP patients sensitive to glucocorticoid treatment than in those insensitive to glucocorticoid treatment (P=0.025). These results were validated using another ITP cohort (N=127, P=0.033). Moreover, the CC genotype was a risk factor for insensitive to GT the odds ratio (95% confidence interval) was 5.96 (5.23-6.69) in standard prednisone (P=0.0069) and 6.35 (5.33-7.37) in high-dose dexamethasone (P=0.04).

CONCLUSIONS

Although HIF1A gene polymorphisms were not associated with susceptibility to ITP, the CT genotype at rs11549465 was associated with the sensitivity to glucocorticoid treatment of ITP patients, suggesting that the rs11549465 SNP may contribute to the sensitivity of glucocorticoid treatment in pediatric ITP patients.

COVID-19 Disease and Associated Thrombocytopenia: Pathogenesis and a Clue to the Etiology

(1) Background: Hospital mortality in patients suffering from SARS-CoV-2 infection has been associated with thrombocytopenia. The present study was conducted to establish the correlation of thrombocytopenia and the severity of infection. The impact of IL-1Ra gene polymorphism on the incidence and severity of thrombocytopenia was also studied. (2) Methods: Various biochemical parameters measured in all the 1200 enrolled patients included full blood counts, renal and liver function tests, iron study, inflammatory markers, and coagulation assays. A further 70 patients each were selected from the severe thrombocytopenic and non-thrombocytopenic patient groups to study the IL-1Ra gene polymorphism by RCR. (3) Results: Out of 1200 patients, 436 (36.3%) had thrombocytopenia. Among these patients, 118 (27.1%), 75 (17.2%), and 42 (9.6%) had mild, moderate, severe, and very severe thrombocytopenia, respectively. Severe cases mostly resulted from peripheral consumption (73.5%), hemo-phagocytosis (15.4%), and bone marrow suppression (11.11%). A statistically significant correlation was found between the occurrence and severity of thrombocytopenia with perturbated levels of inflammatory markers and the presence of comorbidities. The IL-1Ra∗3 variant was found to be significantly associated with thrombocytopenia. The IL-1Ra∗2 variant was significantly seen among controls. (4) Conclusions: The present study revealed a significant correlation between thrombocytopenia and the severity of COVID-19 disease. Moreover, the IL-1Ra∗3 variant of IL-1Ra gene was associated with thrombocytopenia.

Sialic acid and platelet count regulation: Implications in immune thrombocytopenia

Platelets are blood components that survive in circulation for 7 to 10 days in humans. Thus, platelet production by bone marrow (BM) megakaryocytes (MKs), and their removal from the blood circulation is precisely orchestrated to maintain an average platelet count. Abnormalities in both processes can result in thrombocytopenia (low platelet count) or thrombocytosis (high platelet count), often associated with the risk of bleeding or overt thrombus formation, respectively. Platelet glycans, particularly sialic acids, are indicators of platelet count. Loss of platelet sialic acids leads to platelet clearance. A State-of-the-Art lecture titled "Platelet and Megakaryocyte Glycobiology" was presented at the ISTH virtual congress 2021 to discuss (i) the loss of O-glycan sialic acid on BM MKs, revealing the Thomsen-Friedenreich (TF) antigen as a new concept of thrombocytopenia; herein, impaired thrombopoiesis is attributed to activation of immune cells with a plasmacytoid dendritic cell signature; and (ii) upregulation of antibodies against the TF antigen in pediatric patients with immune thrombocytopenia (ITP), positing that glycan alterations such as MK asialylation can lead to immune cell responses. Here, we discuss our findings alongside new data presented at the 2020 and 2021 ISTH congresses on the role of sialic acids and glycans in regulating platelet count. Desialylation is a prominent feature in thrombocytopenia, notably in ITP presentation. We compare similarities between ITP mediated with shear-stress and with storage-related asialylation. We also discuss genes involved in sialic acid synthesis leading to thrombocytopenia. Increased awareness in gene-regulating MK and platelet glycans is a giant leap to understanding the underpinning mechanisms of ITP and other forms of thrombocytopenia.

Primary Immune Thrombocytopenia and Essential Thrombocythemia: So Different and yet Somehow Similar-Cases Series and a Review of the Literature

This article collects several published cases in which immune thrombocytopenic purpura (ITP) is followed by essential thrombocythemia (ET) and vice versa. This surprising clinical condition is possible, but very rare and difficult to diagnose and manage. We have made an attempt to analyse the possible causes of the sequential appearance of ITP and ET taking into consideration the following: alteration of the thrombopoietin (TPO) receptor, the role of autoimmunity and inflammation, and cytokine modulation. A better understanding of these interactions may provide opportunities to determine predisposing factors and aid in finding new treatment modalities both for ITP and ET patients.

The Mechanistic Effects and Clinical Applications of Various Derived Mesenchymal Stem Cells in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by persistent thrombocytopenia resulting from increased platelet destruction and a loss of autoimmune tolerance. The pathogenesis of ITP is highly complex. Although ITP may be effectively controlled with currently available medications in some patients, a subset of cases remain refractory. The application of mesenchymal stem cells (MSCs) for human hematopoietic stem cell transplantation has increasingly demonstrated that MSCs modulate innate or adaptive immunity, thus resulting in a tolerant microenvironment. Functional defects and immunomodulatory disorders have been observed after the use of bone marrow mesenchymal stem cells (BM-MSCs) from patients with ITP. Here, we summarize the underlying mechanisms and clinical applications of various derived MSCs for ITP treatment, focusing on the main mechanisms underlying the functional defects and immune dysfunction of BM-MSCs from patients with ITP. Functional effects associated with the activation of the p53 pathway include decreased activity of the phosphatidylinositol 3 kinase/Akt pathway and activation of the TNFAIP3/NF-κB/SMAD7 pathway. Immune dysfunction appears to be associated with an impaired ability of BM-MSCs to induce various types of immune cells in ITP. At present, research focusing on MSCs in ITP remains in preliminary stages. The application of autologous or exogenous MSCs in the clinical treatment of ITP has been attempted in only a small case study and must be validated in larger-scale clinical trials.

Effect of Cytokine Gene Polymorphisms on Eltrombopag Reactivity in Japanese Patients with Immune Thrombocytopenia

Background

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by low platelet counts resulting from antiplatelet autoantibodies. Analysis of polymorphisms in cytokine-encoding genes is important for understanding the pathophysiology of ITP and selecting appropriate treatments. We investigated associations between polymorphisms in cytokine-encoding genes and responses to therapy in Japanese patients with ITP.

Methods

The participants in this study comprised 153 patients with ITP and 70 healthy controls. We extracted data on sex, age, platelet counts, bleeding symptoms, and therapeutic responses, including those to prednisolone (PSL) and eltrombopag. Genomic DNA was isolated from peripheral blood and polymorphisms in TNF-α, IL-10, TGF-β₁, and IFN-γ genes were analyzed using the PCR-SSP method.

Results

Our results showed that the TGF-β₁ +869 C/C genotype might be related to ITP in Japanese patients. The IL-10 -592 C/C and A/A, -819 C/C and T/T, and -1082, -819, -592 ATA/ATA genotypes might be associated with reactivity to PSL. Furthermore, the IL-10 -592 C/A -819 C/T genotypes, IL-10 ACC/ATA genotype, and TGF-β₁ +869 T/T and T/C genotypes might be linked to the response to eltrombopag.

Conclusion

Our results indicate that analysis of polymorphisms in cytokine-encoding genes could aid in understanding PSL and eltrombopag responsiveness in Japanese patients with ITP.

IL-10 and IL-17 expression by CD4+ T cells is altered in corticosteroid refractory immune thrombocytopenia (ITP)

BACKGROUND

Corticosteroids remain the first-line treatment for patients with immune thrombocytopenia (ITP). However, 20% to 30% of patients do not respond to treatment at tolerable doses. This variation in corticosteroid efficacy is replicated in other autoimmune diseases and may have an adaptive immune basis.

OBJECTIVE

To test the hypothesis that CD4+ T-cell responses to corticosteroids are different in patients with clinically defined corticosteroid refractory ITP.

METHODS

In this prospective cohort study, CD4+ T cells from patients with ITP were cultured in the presence or absence of dexamethasone (Dex). Intracellular cytokine expression was then quantified by flow cytometry and compared with patients' clinical response to corticosteroid treatment. A control cohort of patients with autoimmune uveitis was also studied to evaluate whether our findings were limited to ITP or are potentially generalizable across autoimmune diseases.

RESULTS

The ratio of interleukin (IL)-10 to IL-17 expression following CD4+ T cell culture with Dex was able to discriminate between ITP patients with a clinically defined complete (n = 33), partial (n = 12) or nonresponse (n = 11) to corticosteroid treatment (P = .002). These findings were replicated in patients with autoimmune uveitis (complete response n = 14, nonresponse n = 22; P = .01).

CONCLUSIONS

There is a relative abrogation of IL-10 and persistence of IL-17 expression in the CD4+ T cells of patients who clinically fail corticosteroid therapy. This observation has potential to inform both our mechanistic understanding of the action of corticosteroids in the treatment of ITP, and as a biomarker for steroid refractory disease, with potential application across a range of hematological and nonhematological conditions.

Predicting bleeding risk in a Chinese immune thrombocytopenia (ITP) population: development and assessment of a new predictive nomogram

The aim of this study was to develop a model that could be used to forecast the bleeding risk of ITP based on proinflammatory and anti-inflammatory factors. One hundred ITP patients were recruited to build a new predictive nomogram, another eighty-eight ITP patients were enrolled as validation cohort, and data were collected from January 2016 to January 2019. Four demographic characteristics and fifteen clinical characteristics were taken into account. Eleven cytokines (IFN-γ, IL-1, IL-4, IL-6, IL-8, IL-10, IL-17A, IL-22, IL-23, TNF-α and TGF-β) were used to study and the levels of them were detected by using a cytometric bead array (CBA) human inflammation kit. The least absolute shrinkage and selection operator regression model was used to optimize feature selection. Multivariate logistic regression analysis was applied to build a new predictive nomogram based on the results of the least absolute shrinkage and selection operator regress ion model. The application of C-index, ROC curve, calibration plot, and decision curve analyses were used to assess the discrimination, calibration, and clinical practicability of the predictive model. Bootstrapping validation was used for testing and verifying the predictive model. After feature selection, cytokines IL-1, IL-6, IL-8, IL-23 and TGF-β were excluded, cytokines IFN-γ, IL-4, IL-10, IL-17A, IL-22, TGF-β, the count of PLT and the length of time of ITP were used as predictive factors in the predictive nomogram. The model showed good discrimination with a C-index of 0.82 (95% confidence interval 0.73376-0.90 624) in training cohortn and 0.89 (95% CI 0.868, 0.902) in validation cohort, an AUC of 0.795 in training cohort, 0.94 in validation cohort and good calibration. A high C-index value of 0.66 was reached in the interval validation assessment. Decision curve analysis showed that the bleeding risk nomogram was clinically useful when intervention was decided at the possibility threshold of 16-84%. The bleeding risk model based on IFN-γ, IL-4, IL-10, IL-17A, IL-22, TGF-β, the count of PLT and the length of time of ITP could be conveniently used to predict the bleeding risk of ITP.

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.

Involvement of Interferon-γ + 874A/T Polymorphism in the Pathogenesis of and Therapeutic Response to Immune Thrombocytopenia

BACKGROUND

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by symptoms of thrombocytopenia and bleeding due to production of autoantibodies against platelets. Recently, the occurrence of polymorphisms has been identified as one of the main causes of disease onset.

METHODS

To conduct this study, we recruited 140 patients and control individuals with no history of platelet loss. After collection of specimens, the prevalence of interferon-γ polymorphism was evaluated using the allele-specific oligonucleotide-polymerase chain reaction (ASO-PCR) technique and confirmed by sequencing techniques.

RESULTS

The results showed that the frequency of the AA genotype was higher in the control group, compared with patients with ITP; however, in the acute and chronic groups, the frequency of the AT genotype was higher than that of the AA genotype. We also discovered that there was no significant correlation between platelet counts before and after treatment, nor in its related parameters with interferon (IFN)-γ polymorphism.

CONCLUSION

rs2430561 does not seem to have any role in ITP pathogenesis and treatment response.

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.

Thrombocytopenia in solid tumors: Prognostic significance

Solid tumors are a heterogeneous group of malignancies that result from out-of-control proliferation of cells. Thrombocytopenia is a common complication among patients with solid tumors that predispose them to bleeding disorders. The aim of this review article is to investigate the underlying mechanisms of the risk and incidence of thrombocytopenia in solid tumors. It can be argued that thrombocytopenia is a poor prognostic factor in solid tumors that can result from several factors such as polymorphism and mutation in some transcription factors and cytokines involved in megakaryocytic maturation or from the adverse effects of treatment. Therefore, an understanding of the exact mechanism of thrombocytopenia pathogenesis in each stage of solid tumors can help in developing therapeutic strategies to decrease bleeding complications in these malignancies.

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.

Meta-analyses of IL1A polymorphisms and the risk of several autoimmune diseases published in databases

Background

Based on published data, we aimed to quantitatively elucidate the possible genetic influence of rs17561 G/T and rs1800587 C/T polymorphisms of the IL1A (interleukin 1 alpha) gene in the susceptibility to several autoimmune diseases.

Methods

A series of meta-analyses were carried out. After database searching, we utilized our inclusion/exclusion criteria to screen and include the eligible studies. P_association (P value of association test), Bonferroni-corrected P_association value; false discovery rate (FDR)-corrected P_association, ORs (odd ratios), and 95% CI (confidence interval) were generated to assess the magnitudes of genetic relationships.

Results

A total of 35 eligible articles were included. Pooled analysis data of both rs17561 G/T and rs1800587 C/T in the overall population indicated a negative association between cases of autoimmune diseases and negative controls (all P_association>0.05, Bonferroni-corrected P_association>0.05, FDR-corrected P_association>0.05). Similar results were found in most subgroup analyses (all P_association>0.05, Bonferroni-corrected P_association>0.05, FDR-corrected P_association>0.05), apart from the rs1800587 in the Graves’ disease subgroup, which showed an increased risk in some cases, compared with controls, under the models of allele T vs. C, carrier T vs. C, CT+TT vs. CC, and CT vs. CC (all P_association<0.05, Bonferroni-corrected P_association<0.05, FDR-corrected P_association>0.05, OR>1).

Conclusion

Based on the available data, C/T genotype of the rs1800587 polymorphism within IL1A gene may be associated with an increased Graves’ disease risk. We did not see evidence regarding a positive role for rs1800587 or rs17561 in the risk of other autoimmune diseases, such as systemic sclerosis or rheumatoid arthritis. These conclusions still merit further data support and molecular exploration.

Emerging Concepts in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune disease defined by low platelet counts which presents with an increased bleeding risk. Several genetic risk factors (e.g., polymorphisms in immunity-related genes) predispose to ITP. Autoantibodies and cytotoxic CD8⁺ T cells (Tc) mediate the anti-platelet response leading to thrombocytopenia. Both effector arms enhance platelet clearance through phagocytosis by splenic macrophages or dendritic cells and by induction of apoptosis. Meanwhile, platelet production is inhibited by CD8⁺ Tc targeting megakaryocytes in the bone marrow. CD4⁺ T helper cells are important for B cell differentiation into autoantibody secreting plasma cells. Regulatory Tc are essential to secure immune tolerance, and reduced levels have been implicated in the development of ITP. Both Fcγ-receptor-dependent and -independent pathways are involved in the etiology of ITP. In this review, we present a simplified model for the pathogenesis of ITP, in which exposure of platelet surface antigens and a loss of tolerance are required for development of chronic anti-platelet responses. We also suggest that infections may comprise an important trigger for the development of auto-immunity against platelets in ITP. Post-translational modification of autoantigens has been firmly implicated in the development of autoimmune disorders like rheumatoid arthritis and type 1 diabetes. Based on these findings, we propose that post-translational modifications of platelet antigens may also contribute to the pathogenesis of ITP.

Association Between the Interferon Gamma 874 T/A Polymorphism and the Severity of Valvular Damage in Patients with Rheumatic Heart Disease

Interferon gamma (IFN-γ) is a multifunctional cytokine that plays an important role in modulating almost all phases of the immune response and may be responsible for the increased valvular fibrosis and calcification in the pathogenesis of rheumatic heart disease (RHD). The aim of this study was to investigate the possible relationship between the IFN-γ +874 T/A polymorphism and the severity of valvular damage in the Turkish population. The IFN-γ genotypes were determined in 152 RHD patients and 151 healthy controls by ARMS-PCR. Differences in genotype distribution between patients with RHD and control were evaluated by the χ² test. All statistical analyses were performed with SPSS 15.0 Software program. Frequency of the AA genotype was found to be significantly lower and the TT genotype significantly higher in the RHD group compared to controls (p = 0.002 and p = 0.018, respectively). The TT genotype was found to be significantly higher (26.8% vs. 9.1%, p = 0.009) and the AA genotype significantly lower (29.1% vs. 8.2%, p = 0.001) in the severe valvular disease (SVD) group compared to mild valvular disease group. In the SVD group, 79 patients had mitral balloon valvotomy and/or mitral valve replacement and had significantly higher TT genotype compared to patients with medical follow-up (30.4% vs. 19%, p = 0.001). The data demonstrated that TT genotype is associated with both RHD and the severity of RHD.

Persistent changes in circulating white blood cell populations after splenectomy

The effect of splenectomy on the incidence of infections and thromboembolisms has been investigated thoroughly. Nevertheless, the long-term effects of splenectomy on immunological profile and circulating blood counts have not been described before. To study such long-term effects, we analysed several parameters in splenectomised trauma patients and compared the results of this group ("otherwise healthy patients") to patients with a specific underlying disease. We measured platelet count, leukocytes and differential, lymphocyte subsets, serum levels of immunoglobulins, and complement pathways in 113 patients. Indications to perform a splenectomy were trauma (n = 42), Hodgkin lymphoma (n = 24), hereditary spherocytosis (n = 21), and immune thrombocytopenia (n = 26). In trauma patients lymphocytes and lymphocytes subsets were particularly elevated compared to normal population values. Splenectomised patients with Hodgkin lymphoma had significant lower numbers of T lymphocytes than trauma patients. Significant increases in platelets, leukocytes, and monocytes were observed in patients with hereditary spherocytosis. Occurrence of MBL genotype was different in ITP patients than in other splenectomised groups and the normal population. In splenectomised patients (> 4 years), platelet counts and lymphocyte subsets are increased which persist over time. As a result, these blood counts in splenectomised patients differ from reference values in the normal population.

Inflammation-Related Gene Polymorphisms Associated With Primary Immune Thrombocytopenia

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease characterized by a reduced platelet count and an increased risk of bleeding. Although immense research has improved our understanding of ITP, the pathogenesis remains unclear. Here, we investigated the involvement of 25 single-nucleotide polymorphisms (SNPs) of the inflammation-related genes, including CD24, CD226, FCRL3, IL2, IRF5, ITGAM, NLRP3, CARD8, PTPN22, SH2B2, STAT4, TNFAIP3, and TRAF1, in the pathogenesis and treatment response of ITP. We recruited 312 ITP inpatients and 154 healthy participants in this case–control study. Inflammation-related SNP genotyping was performed on the Sequenom MassARRAY iPLEX platform. The expression of TNFAIP3 mRNA was determined by quantitative real-time RT-PCR. All SNPs in healthy controls were consistent with Hardy–Weinberg equilibrium. Statistical analysis revealed that rs10499194 in TNFAIP3 was significantly associated with a decreased risk of ITP after Bonferroni multiple correction (codominant, CT vs. CC, OR = 0.431, 95% CI = 0.262–0.711, p = 0.001; dominant, TT/CT vs. CC, OR = 0.249, 95% CI = 0.141–0.440, p = 0.000). Besides, TNFAIP3 expression was significantly higher in patients with CT and pooled CT/TT genotypes compared with CC genotype (p = 0.001; p = 0.001). Interestingly, rs10499194 was also associated with corticosteroid-sensitivity (codominant, CT vs. CC, OR = 0.092, 95% CI = 0.021–0.398, p = 0.001; dominant, TT/CT vs. CC, OR = 0.086, 95% CI = 0.020–0.369, p = 0.001; allelic, T vs. C, OR = 0.088, 95% CI = 0.021–0.372, p = 0.001). Furthermore, no significant association was found between inflammation-related SNPs and the severity or refractoriness of ITP after Bonferroni multiple correction. Our findings suggest that rs10499194 may be a protective factor for susceptibility and corticosteroid sensitivity in ITP patients.

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.

Association of genetic polymorphisms in interferon-γ, interleukin-6 and transforming growth factor-β1 gene with oral lichen planus susceptibility

BACKGROUND

Oral lichen planus (OLP) is a premalignant mucocutaneous disease in which genetic factors and immune responses play a major role. Cytokines play an important role in the pathogenesis and disease progression of OLP. The aim of this study was to investigate the impact of gene polymorphisms of T helper cell subtype Th1 and Th2 cytokines, interferon-gamma (IFN-γ), interleukin-6 (IL-6) and transforming growth factor (TGF)-β1 on OLP susceptibility in a Saudi cohort.

METHODS

Forty two unrelated patients with OLP and 195 healthy controls were genotyped for IFN-γ (874A/T), IL-6 (174G/C) and TGF-β1 (509C/T) polymorphisms.

RESULTS

The frequency of genotype AT of IFN-γ (874A/T) was significantly higher while genotype AA was lower in OLP patients as compared to controls (P < 0.05). The frequency of T containing genotypes (AT + TT) was also higher in OLP patients as compared to that in controls (P = 0.003). The frequencies of allele T was higher while that of allele A lower in patients than the controls however the difference was not statistically significant (P = 0.07). There was no significant difference in the frequencies of alleles and genotypes of IL-6 (174G/C) and TGF-β1 (509C/T) polymorphisms between patient and control groups. These results indicated that genotype AT of IFN-γ (874A/T) polymorphism is associated with OLP risk and genotype AA is protective to OLP. On the other hand the polymorphisms IL-6 (174G/C) and TGF-β1 (509C/T) may not be associated with OLP risk in our population.

CONCLUSION

It is concluded that IFN-γ (874A/T) polymorphism is associated with the susceptibility of OLP, however further studies with large sample size involving different ethnic populations should be conducted to strengthen our results.

Association between interferon-γ +874 T/A polymorphism and susceptibility to autoimmune diseases: a meta-analysis

OBJECTIVE

The aim of this study was to explore whether the interferon (IFN)-γ +874 T/A polymorphism plays a role in modifying the risk of autoimmune diseases.

METHODS

A meta-analysis was conducted on the association between the IFN-γ +874 T/A polymorphism and autoimmune diseases.

RESULTS

Eighteen studies with a total of 2952 patients and 3832 controls were included in the meta-analysis. The meta-analysis revealed no association between autoimmune diseases and the IFN-γ +874 T allele in all study subjects (odds ratio (OR)=1.023, 95% confidence interval (CI) = 0.894-1.171, p = 0.738), but stratification by ethnicity indicated an association between the IFN-γ +874 T allele and autoimmune diseases in Latin American subjects (OR = 0.780, 95% CI = 0.629-0.953, p = 0.015). Meta-analysis also revealed an association between autoimmune diseases and the IFN-γ +874 T/A polymorphism in Caucasian and Middle Eastern subjects under a dominant inheritance model (OR = 0.686, 95% CI = 0.489-0.964, p = 0.003; OR = 1.414, 95% CI = 1.102-1.813, p = 0.006). Meta-analysis by autoimmune disease type indicated an association between ITP and the IFN-γ +874 T allele (OR = 1.753, 95% CI = 1.228-2.503, p = 0.002), but not for vasculitis, vitiligo, and auto-immune thyroid disease. Meta-analysis also showed a significant association between the IFN-γ +874 T/A polymorphism and systemic lupus erythematosus (SLE) under the dominant model (OR = 1.668, 95% CI = 1.114-2.497, p = 0.013).

CONCLUSIONS

This meta-analysis indicates that the IFN-γ +874 T/A polymorphism may play a significant role in modifying the risk of autoimmune diseases in Caucasian, Latin American, and Middle Eastern subjects, and in particular shows that the IFN-γ +874 T/A polymorphism is associated with increased genetic susceptibility to idiopathic thrombocytopenic purpura and SLE.

Arg25Pro (c.915G>C) polymorphism of transforming growth factor β1 gene suggests an association with increased risk for Hashimoto's thyroiditis

BACKGROUND

The etiopathogenesis of Hashimoto's thyroiditis (HT) - has not been clearly elucidated although the role of chronic inflammation, endothelial dysfunction, and imbalance between pro- and anti-inflammatory cytokines has been established. Transforming growth factor β1 (TGFβ1) is required to maintain immune homeostasis, and is implicated in lymphocyte infiltration, production of autoantibodies and thyrocyte destruction seen in patients with HT.

AIM

The aim of the present study was to investigate the possible association of Leu10Pro (c.869T>C) and Arg25Pro (c.915G>C) single nucleotide polymorphisms (SNPs) of TGFβ1 gene with the occurrence of HT.

METHODS

We analyzed the genotype and allele frequencies of polymorphisms at codon 10 and 25 in 178 patients who had been diagnosed as having HT and 197 healthy controls using PCR-restriction fragment length polymorphism (RFLP).

RESULTS

There was no notable risk for HT afflicted by Leu10Pro (c.869T>C) polymorphism of TGFβ1 gene. However, there was a significant increase of Arg25Pro (c.915G>C) C allele frequency in patients with HT compared with healthy controls (p=0.003, OR=1.87, 95% CI=1.23-2.84). Moreover, heterozygous (CG) subjects had a 2.53-fold increased risk for developing HT with respect to wild (GG) homozygotes (p<0.001, 95% CI=1.57-4.05). TSH levels in CG heterozygous patients were increased in comparison with wild homozygotes (p=0.006).

CONCLUSION

This study indicates that the Arg25Pro (c.915G>C) polymorphism of TGFβ1 gene may be related to increased risk for HT.

Tumor necrosis factor-α -308G/A gene polymorphism in Egyptian children with immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is an autoimmune disease characterized by increased platelet destruction. Although the cause of ITP remains unclear, it is accepted that both environmental and genetic factors play an important role in the development of the disease. Children with ITP have a T-helper 1-type cytokine pattern with elevated levels of tumor necrosis factor-alpha (TNF-α) as in most autoimmune diseases. Researchers have shown that polymorphism in the TNF-α gene at position -308 affects gene transcriptions with increased TNF-α production. The current case-control study aimed at detecting the frequency of TNF-α -308G/A gene polymorphism as genetic markers in Egyptian children with ITP, and to clear out their possible role in choosing the treatment protocols of therapy, using PCR restriction fragment length polymorphism assay. Ninety-two ITP patients and 100 age and sex-matched healthy controls were recruited in the study. The results obtained revealed that the frequency of TNF-α -308A/A homotype in ITP patients was significantly higher than that of the controls, and conferred almost six-fold increased risk of ITP acquisition. The polymorphic A allele frequency was significantly higher in ITP patients than in the controls, conferring almost two-fold increased ITP risk. In conclusion, our study suggests the possibility that TNF-α -308 gene polymorphism may contribute to the susceptibility of childhood ITP in Egyptian children.

A Study of Human Killer Cell Immunoglobulin-Like Receptor and Multidrug Resistance Gene Polymorphisms in Children With Immune Thrombocytopenia

THE OBJECTIVE

This study was undertaken to detect characterization of the different gene polymorphisms in Human killer cell immunoglobulin-like receptor (KIR2) gene and multi-drug resistance (MDR1) gene, among childhood ITP Egyptian patients. In addition to assess the potential role of these polymorphisms in relation to types of ITP and response to different treatment modalities.

PATIENTS AND METHODS

A total of 48 pediatric patients with immune thrombocytopenia (ITP; 24 newly diagnosed and 24 chronic) and 35 healthy controls were investigated via polymerase chain reaction-restriction fragment length polymorphism analysis for multidrug resistance (MDR) 1 and killer cell immunoglobulin-like receptor (KIR) 2 genes.

RESULTS

The frequency of MDR1 gene in patients and control was not significant (P = .090). The CT genotype was the highest distribution among all ITP cases (62.50%, n = 30) and control (48.60%, n = 17). There was a significant difference in age at diagnosis of MDR1 gene with the CC genotype had the eldest age and lowest initial platelets count (P = .029 and P = .004). The distribution of KIR2 gene among all patients with ITP and controls was significant (P = .026) with (KIRDL2-/KIRDS2-) genotype was the most prevalent among patients.

CONCLUSION

The frequency of MDR1 polymorphisms was not associated with susceptibility to the development and clinical progression of the disease. However, KIR2 gene polymorphisms were independently associated with childhood ITP in Egyptian patients with highest prevalence among (KIRDL2-/KIRDS2-) genotypes.

In vitro TNF blockade enhances ex vivo expansion of regulatory T cells in patients with immune thrombocytopenia

Tumour necrosis factor-α (TNF) is an inflammatory cytokine that is elevated in a number of autoimmune diseases including immune thrombocytopenia (ITP), a bleeding disorder characterized by low platelet counts. In vitro TNF blockade increases expansion of the regulatory T cell (Treg) IKZF2 (also termed Helios) subset in T cell-monocyte cocultures from healthy donors, but its role on proliferative responses of Tregs in ITP patients, who have altered immunoregulatory compartment, remains unclear. TNF in CD4+ T cells from patients with chronic ITP were elevated and negatively correlated with peripheral Treg frequencies, suggesting a possible inhibitory effect of TNF on ITP Tregs. In vitro antibody neutralization with anti-TNF in T cell-monocyte cocultures resulted in a robust expansion of pre-existing ITP Tregs, higher than in healthy controls. Similar to the effects of anti-TNF antibodies, TNF blockade with antibodies against TNFRSF1B (anti-TNFRSF1B, previously termed anti-TNFRII) almost doubled ITP Treg expansion whereas neutralization with anti-TNFRSF1A (anti-TNFRI) antibodies had no effect on proliferative responses of Tregs. In addition, TNFRSF1B levels on ITP Tregs were significantly elevated, which may explain the increased susceptibility of patient Tregs to the actions of TNF blockade. Altogether, these data raise the possibility that TNF blockers, through their ability to increase Treg proliferation, may be efficacious in ITP patients.

TNF-α promoter single nucleotide polymorphisms and haplotypes associate with susceptibility of immune thrombocytopenia in Chinese adults

OBJECTIVE

Tumor necrosis factor-alpha (TNF-α) participates as a candidate susceptibility factor for immune thrombocytopenia (ITP). This study attempted to investigate the association between five single nucleotide polymorphisms (SNPs) spanning the TNF-α promoter and the susceptibility of primary ITP in Chinese Han adults.

METHODS

In 215 adult primary ITP patients and 206 healthy controls, SNPs were detected by PCR-RFLP and PCR-SSP. The χ(2) test or fisher's exact test was used to compare frequencies of genotypes and alleles between patients and controls. Haplotypes were analyzed with the SHEsis online program. TNF-α, IFN-γ and Galectin-9 mRNA of 35 newly diagnosed adult ITP patients and 35 healthy controls were detected by qRT-PCR.

RESULTS

The haplotype GGC (-238G/-308G/-857C) of TNF-α promoter was significantly associated with a decreased susceptibility of primary ITP, especially in males. The relative levels of mRNA expression of TNF-α, IFN-γ and Gal-9 in adult active primary ITP patients was significantly up-regulated compared with patients in remission and controls.

CONCLUSIONS

This study represented the first report that the haplotype GGC of TNF-α was differentially associated with the susceptibility of primary ITP in Chinese Han adults. The up-regulation of TNF-α, IFN-γ and Galectin-9 was significantly correlated with active primary ITP in adult patients.

Effect of pro-inflammatory cytokine (IFN-γ +874, IL-18-137 G/C,-607 C/A) genes in relation to risk of vesico-ureteral reflux

AIM

The aim this work is to estimate whether genetic polymorphisms of +874 of IFN-γ and -137 G/C,-607 C/A of IL-18 genes are implicated in the development of VUR, because a vast literature indicates that genetic variations play a significant role in the pathogenesis of VUR.

MATERIALS AND METHODS

The PCR single specific primer (SSP) and amplification refractory mutation system (ARMS) were applied for analyzing the polymorphic sites of -137 G/C,-607 C/A of IL-18 and +874 of IFN-γ genes in 110 healthy controls and 124 VUR children.

RESULTS

A significant relationship was found between AT and combined AT + TT genotypes of IFN-γ and highly increased risk of VUR (OR = 4.2, 95% CI, 2.00-9.24; p < 0.0001: OR = 4.00, 95% CI, 1.90-8.70, p < 0.0001, respectively). On the other hand, the genotype frequency of IL18-137 G/C indicated a significant assessment of the decrease risk of VUR for GC and GC + CC genotypes (OR = 0.53, 95% CI, 0.3-0.9; p = 0.02: OR = 0.53, 95% CI, 0.3-0.92 p = 0.01, respectively). No significant association was found between -607 C/A polymorphism of IL-18 and UVR.

CONCLUSION

To the author's best knowledge, this is the first data regarding polymorphism of IFN-γ (+874) cytokine genes that highly increased the risk of VUR. To confirm the presented data, further studies should be done in different populations with a larger sample size.

Involvement of levels of Toll like receptor-4 in monocytes, CD4+ T-lymphocyte subsets, and cytokines in patients with immune thrombocytopenic purpura

INTRODUCTION

Toll-like receptors have been found to be associated with immune-mediated diseases but it is still not clear whether they play a role in immune thrombocytopenic purpura (ITP), especially TLR4. CD4+ T-lymphocyte abnormalities, including Th17, Th1, Th2, and regulator T cell (Treg), are considered important in ITP. There have been few studies regarding the expression of TLR4 and the relationships between TLR4 and Th17 levels in ITP.

MATERIALS AND METHODS

In this study, we evaluated the expression of TLR4 in monocytes, the plasma concentrations of IL-23, IL-17 and the profiles of Th17, Th1, Th2 cells in 70 patients with ITP and 31 healthy controls. In addition, we evaluated IL-2 and Treg cells in 46 cases of 70 patients with ITP and the same 31 controls.

RESULTS

Higher levels of TLR4 expression, higher relative numbers of Th17 and Th1 cells and lower levels of Treg cells were observed in patients when compared with controls (p=0.001 for TLR4; p<0.001 for Th17; p=0.014 for Th1; p=0.001 for Treg). The levels of IL-23 and IL-2 were increased (p=0.022 for IL-23; p=0.025 for IL-2), the relative levels of Th2 and concentrations of IL-17 were similar across both groups (p=0.446 for Th2; p=0.316 for IL-17). A significant negative correlation was observed between levels of TLR4 and Treg(r=-0.544, p<0.001), but a significantly positive correlation was observed between IL-2 and IL-23 concentration in patients (r=0.441, p=0.004). Neither the correlation between TLR4 and the other CD4(+) T cells and cytokines nor the correlation between the three cytokines and CD4+ T cells was found to be statistically significant.

CONCLUSIONS

Our data showed that TLR4, CD4+ T cells (Th1, Th17 and Treg cells) and related cytokines (IL-23, IL-2) may take part in the pathogenesis of ITP. TLR4 may play a role through the TLR4-cytokine-CD4+ T lymphocyte cell pathway.

DNA methyltransferase 3B gene promoter and interleukin-1 receptor antagonist polymorphisms in childhood immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is one of the most common blood diseases as well as the commonest acquired bleeding disorder in childhood. Although the etiology of ITP is unclear, in the pathogenesis of the disease, both environmental and genetic factors including polymorphisms of TNF-a, IL-10, and IL-4 genes have been suggested to be involved. In this study, we investigated the rs2424913 single-nucleotide polymorphism (SNP) (C46359T) in DNA methyltransferase 3B (DNMT3B) gene promoter and the VNTR polymorphism of IL-1 receptor antagonist (IL-1 Ra) intron-2 in 32 children (17 boys) with the diagnosis of ITP and 64 healthy individuals. No significant differences were found in the genotype distribution of DNMT3B polymorphism between the children with ITP and the control group, whereas the frequency of allele T appeared significantly increased in children with ITP (P = 0.03, OR = 2, 95% CI: 1.06-3.94). In case of IL-1 Ra polymorphism, children with ITP had a significantly higher frequency of genotype I/II, compared to control group (P = 0.043, OR = 2.60, 95% CI: 1.02-6.50). Moreover, genotype I/I as well as allele I was overrepresented in the control group, suggesting that allele I may have a decreased risk for development of ITP. Our findings suggest that rs2424913 DNMT3B SNP as well as IL-1 Ra VNTR polymorphism may contribute to the susceptibility to ITP.

Role of cytokine gene (IFN-γ, TNF-α, TGF-β1, IL-6, and IL-10) polymorphisms in pathogenesis of acute rheumatic fever in Turkish children

Acute rheumatic fever (ARF) is a delayed immunologically mediated sequela of throat infection by group A β-hemolytic streptococci. Inflammatory cytokines may play a pathogenic role in ARF. The objective of this study was to investigate the potential associations between interferon (IFN)-γ, interleukin (IL)-6, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, and IL-10 gene polymorphisms and childhood ARF. Thirty-eight ARF patients and 40 age- and sex-matched healthy controls were analyzed for eight polymorphisms in five different cytokine genes [IFN-γ (+874), IL-6 (-174), TNF-α (-308), TGF-β1 (+10, +25), and IL-10 (-1082, -819, -592)]. Cytokine genotyping was performed by polymerase chain reaction sequence-specific primer methods. Patients with ARF had significantly higher frequencies of IFN-γ (+874) polymorphism in both TT genotype (p=0.0002) and T allele (p=0.0004). No statistically significant differences were observed in genotypes, haplotypes, and allele frequencies of IL-6, TNF-α, TGF-β1, and IL-10 genes between ARF and control groups (p>0.05). GG genotype frequency of TNF-α gene (low expression) was higher in patients who had previous ARF history (p=0.006). High expression of TGF-β1 (TT/GG, TC/GG) was more frequent in patients with CRP positivity (p=0.034). IL-6 CC genotype (low expression) frequency was higher in patients with tricuspid valve insufficiency (p=0.002), while IFN-γ TT genotype (high expression) frequency was higher in patients with mitral valve prolapse (p=0.049).

CONCLUSION

High expression of the IFN-γ gene may carry a higher risk for ARF in Turkish children, while IL-6, TNF-α, and TGF-β1 may have an impact in mediating some clinical and laboratory manifestations of the disease.