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

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.

Immune thrombocytopenia: a review on the pathogenetic role of immune cells

INTRODUCTION

Immune thrombocytopenia [ITP] is a common bleeding disorder with an isolated platelet count of less than 100 × 109/L.

AREAS COVERED

Relevant literature from 2003 to 2022 was retrieved and reviewed from the Google Scholar search engine and PubMed database. Antibodies produced by autoreactive B lymphocytes and the phagocytic function of macrophages are considered the most critical factors in platelet destruction. Also, macrophages present the antigen to T lymphocytes and activate them. Follicular helper T-cells [TFH] play a role in stimulating, differentiating, and activating autoreactive B cells, while cluster of differentiation [CD]-8+ T plays a role in platelet destruction through apoptosis. The classical pathway of the complement system also causes platelet destruction. By inhibiting platelet production, low levels of thrombopoietin and an immune response against megakaryocytes in the bone marrow worsen thrombocytopenia.

EXPERT OPINION

T-cell subset changes and an increase in activated autoreactive B cells, in addition to the function of components of the innate immune system [the complement system, dendritic cells, and natural killer cells], play a critical role in the pathogenesis of the ITP. Accurate detection of these changes may lead to developing new therapeutic strategies and identifying better prognostic/diagnostic factors.

Genome-wide DNA methylation profiling of CD4+ T lymphocytes identifies differentially methylated loci associated with adult primary refractory immune thrombocytopenia

BACKGROUND

DNA methylation played a crucial role in the pathogenesis of immune thrombocytopenia (ITP). However, genome-wide DNA methylation analysis has not been applied thus far. The present study aimed to provide the first DNA methylation profiling for ITP.

METHODS

Peripheral blood CD4+ T lymphocytes samples were collected from 4 primary refractory ITP cases and 4 age-matched healthy controls, and DNA methylome profiling was performed using Infinium MethylationEPIC BeadChip. Differentially methylated CpG sites were further validated in another independent cohort of 10 ITP patients and 10 healthy controls using qRT-PCR.

RESULTS

The DNA methylome profiling identified a total of 260 differentially methylated CpG sites mapping to 72 hypermethylated and 64 hypomethylated genes. These genes were mainly enriched in the actin nucleation of the Arp2/3 complex, vesicle transport, histone H3-K36 demethylation, Th1 and Th2 cell differentiation, and Notch signaling pathway according to the GO and KEGG databases. The mRNA expression of CASP9, C1orf109, and AMD1 were significantly different.

CONCLUSIONS

Given the altered DNA methylation profiling of ITP, our study provides new insights into its genetic mechanism and suggests candidate biomarkers for the diagnosis and treatment of ITP.

FcγRIIa and FcγRIIIa genes polymorphism in Egyptian children with primary immune thrombocytopenia

INTRODUCTION

Phagocytosis of autoantibody-sensitized coated platelets through Fc gamma receptors on phagocytic cells is an important mechanism of thrombocytopenia in primary immune thrombocytopenia (ITP).

OBJECTIVE

We aimed to investigate the contribution of the FcγRIIa and FcγRIIIa genes polymorphism to the risk of ITP and their association with disease characteristics in Egyptian children.

METHODS

A case control study was conducted on eighty children with primary ITP and eighty age and sex healthy matched subjects as a control group. The FcγRIIa and FcγRIIIa genes polymorphism was detected using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We found that the FcγRIIa-131H and -131R allele frequencies were 51.3 % and 48.7%, respectively, in children with ITP, versus 75% and 25%, respectively, in controls (p = 0.002). The compound heterozygous HR genotype was significantly higher in ITP patients (p < 0.05). The FcγRIIIa-158F and -158V allele frequencies were 46.3% and 53.7%, respectively, in children with ITP, versus 70% and 30%, respectively, in controls (p = 0.002). The compound heterozygous VF genotype was significantly higher in ITP patients (p < 0.05). The combined HR/FV genotype was 47.5% in ITP patients, versus 10% in controls (p < 0.001). No significant difference was found between children with newly diagnosed ITP and those who developed chronic ITP, regarding the frequency distribution of the FcγRIIa and FcγRIIIa alleles and genotypes (p > 0.05).

CONCLUSION

There is a possible association of the FcγRIIa and FcγRIIIa genes polymorphism with the risk for, and genetic susceptibility to ITP in Egyptian children, but large-scale studies are still needed to support our findings.

Stromal Derived Factor-1 Gene Polymorphism in Pediatric Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a multifactorial disease in which both environmental and genetic factors have been implicated. The study aimed to investigate a possible association of single nucleotide polymorphisms (SNPs rs266085 and rs2839693) in the stromal derived factor-1 (SDF-1) gene and its association to ITP and effect on ITP severity and response to treatment. Genomic DNA was extracted from peripheral blood and polymorphism in SDF-1 gene rs266085 and rs2839693 was analyzed using PCR-restriction fragment length polymorphism technique in DNA extracted from 60 children with ITP together with 90 healthy controls. On analysis of SDF-1 rs266085 polymorphism, there was a high frequency of CC genotype in cases than controls and that difference was significant at codominant, overdominant, and dominant models (P<0.05). Furthermore, carriers of the CC genotype were more susceptible to severe ITP at onset, steroid dependency, and chronicity than carriers of other genotypes (P<0.05). Otherwise, no significant differences between ITP patients and controls as regard SDF-1 rs2839693 genotypes and alleles, and we did not find a relation between this polymorphism and ITP severity, steroid dependency, or duration. SDF-1 gene rs266085 SNP C allele is associated with susceptibility to develop ITP as well as increases the risk for severe ITP at onset, chronic ITP and steroid dependency.

Prevalence of Cytomegalovirus (CMV) and Epstein-Barr Virus (EBV) Subclinical Infection in Patients with Acute Immune Thrombocytopenic Purpura (ITP)

Background: Immune thrombocytopenic purpura (ITP) defined as a bleeding disorder in which the number and production of platelets reduced by the immune system; however, the destruction of peripheral blood platelets also occurs. Although its exact etiology and pathogenesis not already know, several studies have shown that Epstein-Barr virus (EBV) and cytomegalovirus (CMV) known as possible causative agents of ITP. This investigation aims to evaluate the presence of CMV and EBV in two groups of case and control by polymerase chain reaction (PCR).

Materials and Methods: we considered the presence of CMV and EBV in 48 acute ITP patients and 48 healthy people. Study participants were recruited from Ahvaz Shafa Hospital between 2017 and 2018 and the presence of two viruses was investigated by (PCR).

Results: Out of 48 acute ITP patients, the CMV DNA was detected from the blood of 12 (25%) patients and the EBV DNA from the blood of 2 (4.2%) other patients. In addition, only one patient was (2.1%) co-infected with CMV and EBV. In contrast, in 48 healthy subjects, 3 (6.6%) had CMV and none of the control group was infected with EBV.

Conclusion: Due to the presence of both EBV and CMV in the acute ITP patients in Ahvaz, they can be considered as factors in the progression of this disease. Therefore, consideration of the methods of elimination and treatment of these two viruses in these patients may be used as a treatment strategy in ITP patients in the future.

Clinical efficacy of high-dose dexamethasone with sequential prednisone maintenance therapy for newly diagnosed adult immune thrombocytopenia in a real-world setting

OBJECTIVE

As first-line treatments for newly diagnosed adult immune thrombocytopenia (ITP), high-dose dexamethasone (HD-DXM) and conventional-dose prednisone achieve good initial responses, but their long-term efficacy is poor. To improve the long-term outcome of newly diagnosed ITP, we explored the efficacy and safety of HD-DXM with sequential prednisone maintenance therapy.

METHODS

This retrospective study in a real-world setting assessed 72 consecutive newly diagnosed ITP patients administered first-line HD-DXM with sequential prednisone maintenance therapy from 1 June 2016 to 31 December 2019.

RESULTS

Seventy patients obtained response (97.2%), and 55 achieved sustained response (SR) (76.4%). Fifty-three obtained complete remission (CR) (73.6%), and 39 achieved continuous CR at 6 months (54.2%). Among 36 anti-nuclear antibody-positive patients, 100% achieved response, and 28 achieved CR (77.8%). Among 24 antithyroid antibody-positive patients, 23 (95.8%) achieved response, and 20 achieved CR (83.3%). For patients with initial response, the 12-month probability of SR was 78.6%. For patients with initial CR, the 12-month probability of continuous CR was 64.2%. At 12 months, 21.4% of patients with initial response and 11.3% of patients with initial CR showed loss of treatment response.

CONCLUSIONS

HD-DXM with sequential prednisone as the first-line treatment for newly diagnosed ITP patients may achieve good clinical efficacy.

A Pooling Genome-Wide Association Study Identifies Susceptibility Loci and Signaling Pathways of Immune Thrombocytopenia in Chinese Han Population

Immune thrombocytopenia (ITP) is an acquired bleeding disease due to immune-mediated destruction of antilogous platelets and ineffective thrombopoiesis. Although the etiology of ITP remains unknown, genetic variants are thought to predispose individuals to the disease. Several candidate gene analyses have identified several loci that increased ITP susceptibility, but no systematic genetic analysis on a genome-wide scope. To extend the genetic evidence and to identify novel candidates of ITP, we performed a pooling genome-wide association study (GWAS) by IlluminaHumanOmniZhongHua-8 combining pathway analysis in 200 ITP cases and 200 controls from Chinese Han population (CHP). The results revealed that 4 novel loci (rs117503120, rs5998634, rs4483616, and rs16866133) were strongly associated with ITP (P < 1.0 × 10⁻⁷). Expect for rs4483616, other three loci were validated by the TaqMan probe genotyping assay (P < 0.05) in another cohort including 250 ITP cases and 250 controls. And rs5998634 T allele was more sensitive to glucocorticoids for ITP patients (χ² = 7.30, P < 0.05). Moreover, we identified three overrepresented signaling pathways including the neuroactive ligand-receptor interaction, pathways in cancer, and the JAK-STAT pathway, which involved in the etiology of ITP. In conclusion, our results revealed four novel loci and three pathways related to ITP and provided new clues to explore the pathogenesis of ITP.

Impact of CD40 gene polymorphisms on the risk of immune thrombocytopenic purpura

OBJECTIVES

To evaluate the relationship between two common single nucleotide polymorphisms (SNPs) of CD40 gene (rs1883832 C/T and rs4810485 G/T) and the risk of immune thrombocytopenia (ITP) in the Egyptian population.

METHODS

A case-control study was conducted retrospectively on 101 cases with ITP and 97 healthy subjects. Two SNPs of CD40 gene (rs1883832 C/T and rs4810485 G/T) were genotyped via Taqman allele discrimination real-time PCR. The frequencies of different genetic models of both SNPs were calculated and compared between ITP cases and controls. Linkage analysis was performed between the studied SNPs. Odds ratio (OR) and 95% confidence interval (CI) were assessed using multinomial logistic regression analysis to determine the association of CD40 gene SNPs genotypes, alleles, and haplotypes with the risk of ITP. The odds ratio was further adjusted to the confounders for risk stratification.

RESULTS

CD40 (rs1883832) TT genotype carriers have a significantly higher risk of ITP when compared to CC genotype carriers (adjusted OR: 3.792, 95%CI: 1.252-11.49, P = 0.018). T allele also represents 1.711-fold increased risk of ITP which is more evident in males (P = 0.016). No significant difference was observed in the frequency of CD40 (rs4810485 G/T) genetic models between cases and controls. Linkage disequilibrium was found between the two SNPs and revealed four main haplotypes (C-G; C-T; T-G; T-T) with a significantly higher frequency of T-G haplotype in ITP cases than in healthy controls which confers an increased risk of ITP development (OR: 2.349, 95%CI: 1.271-4.339, P = 0.006).

CONCLUSIONS

CD40 gene SNP rs1883832 is associated with an increased risk of ITP development in the Egyptian population, while the SNP rs4810485 has no association. Moreover, T-G haplotype is a risk genetic model for ITP.

HLA-B5, 7, 8, 27, and 51 Antigens and Immune Thrombocytopenic Purpura: Is There an Association?

BACKGROUND

Immune thrombocytopenic purpura (ITP) is a bleeding disorder characterized by low platelet counts in peripheral blood, impairment of thrombopoiesis in bone marrow, and risk of mild to severe bleedings. ITP can be seen among both sexes in different ages. Although definitive pathogenesis of this disorder is still ambiguous, some of risk factors for ITP are recognized, including human leukocyte antigens (HLAs).

OBJECTIVE

Our goal was to evaluate the possible association between HLA-B5, 7, 8, 27, and 51 antigens with ITP for the first time. We were hoping to achieve new hypothetical diagnostic/prognostic biomarkers to introduce a new subject for further studies on HLA class I antigens as possible risk factors for ITP.

MATERIALS AND METHODS

A total of 37 patients with ITP were included in this study. After confirmation of ITP diagnosis, peripheral blood samples were collected from them. The expression of each of HLA antigens was evaluated by standard lymphocytotoxicity technique.

RESULTS

Compared with other studied antigens, the expression of HLA-B5 and HLA-B51 was more prevalent among our patients. According to the results, 22% of patients were positive for HLA-B5 and HLA-B51. Furthermore, no significant association was found between HLAs expressions with complete blood count parameters.

CONCLUSIONS

We conclude that there is an association between HLA-B5 and HLA-B51 with ITP and that they are not likely to be used as diagnostic or prognostic biomarkers. We suggest studying the association between HLA-B antigens and ITP in large-scale studies to determine whether or not there is a significant association.

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.

Prognostic significance of mutated genes in megakaryocytic disorders

Megakaryopoiesis is a process during which platelets that play a major role in hemostasis are produced due to differentiation and maturation of megakaryocytic precursors. Several genes, including oncogenes and tumor suppressor genes, play a role in the regulation of this process. This study was conducted to investigate the oncogenes and tumor suppressor genes as well as their mutations during the megakaryopoiesis process, which can lead to megakaryocytic disorders. Relevant literature was identified by a PubMed search (1998-2019) of English language papers using the terms ‘Megakaryopoiesis’, ‘Mutation’, ‘oncogenes’, and ‘Tumor Suppressor’. According to investigations, several mutations occur in the genes implicated in megakaryopoiesis, which abnormally induce or inhibit megakaryocyte production, differentiation, and maturation, leading to platelet disorders. GATA-1 is one of the important genes in megakaryopoiesis and its mutations can be considered among the factors involved in the incidence of these disorders. Considering the essential role of these genes (such as GATA- 1) in megakaryopoiesis and the involvement of their mutations in platelet disorders, study and examination of these changes can be a positive step in the diagnosis and prognosis of these diseases.

Therapeutic effects of rituximab combined with cyclophosphamide on refractory idiopathic thrombocytopenic purpura

Therapeutic effects of rituximab combined with cyclophosphamide on refractory idiopathic thrombocytopenic purpura (ITP) were investigated. We retrospectively analyzed 249 patients with refractory ITP who were admitted to Qingdao Hiser Medical Group between March 2013 and March 2017. Curative effects of patients treated with rituximab, cyclophosphamide, and combination therapy were observed and the changes of platelet count, PA IgG, and lymphocyte CD20 before and after treatment, as well as the incidence of adverse reactions after treatment, were compared. There was no significant difference in the expression of lymphocyte CD20, PA IgG and platelet count among the three groups of refractory ITP patients before treatment (P>0.05). After treatment, the expression levels of CD20 and PA IgG in lymphocytes were significantly downregulated, and platelet counts significantly increased in the three groups (P<0.05). After treatment, CD20 and PA IgG levels in combined therapy group were significantly lower, and platelet count was significantly higher, than those in the rituximab and cyclophosphamide groups (P<0.05). Also, after rituximab treatment, the expression levels of CD20 and PA IgG in lymphocytes were significantly lower than those in cyclophosphamide group (P<0.05), and platelet count was higher than that in cyclophosphamide group (P<0.05). After treatment, the total effective rate in combined therapy group was higher than that in the rituximab and cyclophosphamide group (P<0.05). Total effective rate of rituximab group was significantly higher than that of cyclophosphamide group (P<0.05). The incidence of adverse reactions in combined therapy group was 14.29% (12/84), which was significantly lower than that in cyclophosphamide group (40.70%, 35/86, P<0.05) and rituximab group (29.11%, 23/79, P<0.05). The application of rituximab combined with cyclophosphamide in the treatment of refractory ITP can improve patients clinical symptoms. The efficacy of this technique is promising with no serious adverse reactions. This technique should be popularized in clinical practice.

The Association Between Human Leukocyte Antigens and ITP, TTP, and HIT

BACKGROUND

Autoimmune thrombocytopenia in immune thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), and heparin-induced thrombocytopenia (HIT) is associated with immunologic degradation of platelets and reduced platelet counts in patients, leading to bleeding risk in patients. Considering the role of human leukocyte antigens (HLA) in the development of immune response, in this review, we examine the relationship between HLA and pathogenesis of the above-mentioned diseases.

METHODS

Relevant English-language literature was searched and retrieved from Google Scholar search engine and PubMed database (1979 to 2018). The following keywords were used: "Immune Thrombocytopenic purpura," "Thrombotic Thrombocytopenic Purpura," Human Leukocyte Antigen," and "Heparin-induced thrombocytopenia."

RESULTS

In autoimmune thrombocytopenia, HLA molecule presents self-antigens or foreign antigens similar to self-antigens, provoking an immune response against platelets that results in the degradation of platelets in peripheral blood and possible bleeding in the patient. For example, HLA-DRB1 *11 presents the self-antigen and induces an immune response against ADAMTS13, which is associated with thrombocytopenia in TTP patients.

CONCLUSIONS

HLA alleles can be used as prognostic biomarkers for immunologic disorders of platelet such as ITP, TTP, and HIT. Different DRB1 alleles enable the assessment of resistance to common ITP treatments as well as disease prognosis. Due to the genetic association between HLA-DR1 and HLA-DQ1 alleles and the role of HLA-DRB1 *11 in TTP, the HLA-DQB1 *02: 02 allele may also play a role in TTP pathogenesis.

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.

Cellular expression of CD markers in immune thrombocytopenic purpura: implications for prognosis

Immune thrombocytopenic purpura (ITP) is an autoimmune bleeding disorder associated with platelet destruction. Abnormalities in frequency and function of different immune cells can play a crucial role in this disease. The aim of this study was to evaluate the prognostic value of CD markers' expressions by immune cells in ITP. Peripheral blood samples were collected from 25 ITP patients before and after treatment. The expression of CD markers was evaluated by flow cytometry technique. The expression of CD38 and CD56 was significantly lower before treatment than after it (p = 0.025 and p = 0.036, respectively). Furthermore, a positive correlation was found between CD38 expression with platelet count before (r = 0.496, p = 0.012) and after treatment (r = 0.404, p = 0.045). No significant relationship was found between this marker and platelet count while CD4 expression was higher before treatment than after it (p = 0.002). In conclusion, CD38 may have independent prognostic value in ITP and we suggest that it can be a prognostic marker for this disease.

Nationwide Trend Analysis of Pediatric Inpatients With Immune Thrombocytopenia in the United States

BACKGROUND

Several studies have reported the epidemiology of immune thrombocytopenia (ITP) among children in the United States and other countries. However, recent trends in ITP among hospitalized children and hospital course remain unknown at a national level in the United States.

METHOD

Hospital discharge records of patients with ITP aged 19 years and younger were obtained for the years 2003, 2006, 2009, and 2012 using the Kids' Inpatient Database. Data were weighted to estimate the annual hospitalization rates in the United States with trend analyses. Multivariable regression models were used to ascertain trends of health care utilizations, hospitalization costs, and length of stay.

RESULTS

Total annual hospitalization rates due to ITP ranged from 6.13 per 100,000 children in 2003 to 6.22 per 100,000 children in 2012 (Ptrend=0.86). The lowest proportions of hospitalizations were observed in August. The proportions of inpatients treated with intravenous immunoglobulin increased from 18.5% in 2003 to 39.9% (Ptrend< 0.001), while those examined with bone marrow aspiration decreased from 7.8% in 2003 to 6.5% in 2012 (Ptrend=0.01). Total hospitalization costs and length of stay changed from $6147 and 3.78 days in 2003 to $9328 and 2.55 days in 2012.

CONCLUSIONS

We provided insights of epidemiology of ITP and health care utilizations in the United States. Further studies, including cost-effective analyses, will be required to justify the increasing trends in health care costs and intravenous immunoglobulin.