The miR-641-STIM1 and SATB1 axes play important roles in the regulation of the Th17/Treg balance in ITP.

Immune thrombocytopenia (ITP) is an autoimmune disease caused by T-cell dysfunction. Recently, several studies have shown that a disturbed Th17/Treg balance contributes to the development of ITP. MicroRNAs (miRNAs) are small noncoding RNA moleculesthat posttranscriptionally regulate gene expression. Emerging evidences have demonstrated that miRNAs play an important role in regulating the Th17/Treg balance. In the present study, we found that miR-641 was upregulated in ITP patients. In primary T cells, overexpression of miR-641 could cause downregulation of its target genes STIM1 and SATB1, thus inducing a Th17 (upregulated)/Treg (downregulated) imbalance. Inhibition of miR-641 by a miR-641 sponge in primary T cells of ITP patients or by antagomiR-641 in an ITP murine model could cause upregulation of STIM1 and SATB1, thus restoring Th17/Treg homeostasis. These results suggested that the miR-641-STIM/SATB1 axis plays an important role in regulating the Th17/Treg balance in ITP.

Immune Thrombocytopenic Purpura (ITP) and Chorioretinopathy in Chronic Granulomatous Disease: A Case Report.

BACKGROUND: Chronic Granulomatous Disease (CGD) is a rare immunodeficiency disorder characterized by impaired phagocytic function, leading to recurrent infections and granuloma formation. Genetic mutations in NADPH oxidase complex components, such as CYBB, NCF1, NCF2, and CYBA genes, contribute to the pathogenesis. This case report explores the possible ocular and hematologic complications associated with CGD. CASE PRESENTATION: A 6-year-old girl with a history of vitrectomy, membranotomy, and laser therapy due to congenital blindness (diagnosed with chorioretinopathy) was referred to the hospital with generalized ecchymosis and thrombocytopenia. Diagnostic workup initially suggested chronic immune thrombocytopenic purpura (ITP). Subsequent admissions revealed necrotic wounds, urinary tract infections, and recurrent thrombocytopenia. Suspecting immunodeficiency, tests for CGD, Nitroblue tetrazolium (NBT) and dihydrorhodamine (DHR) were performed. She had a low DHR (6.7), and her NBT test was negative (0.0%). Her whole exome sequencing results confirmed autosomal recessive CGD with a homozygous NCF1 mutation. CONCLUSION: This case underscores the diverse clinical manifestations of CGD, including recurrent thrombocytopenia and possible early-onset ocular involvement. The diagnostic challenges highlight the importance of a multidisciplinary approach involving hematologists, immunologists, and ophthalmologists for accurate diagnosis and management. The rare coexistence of ITP in CGD emphasizes the intricate link between immunodeficiency and autoimmunity, requiring tailored therapeutic strategies.

Identification of metabolism-related key genes as potential biomarkers for pathogenesis of immune thrombocytopenia.

Immune thrombocytopenia (ITP), an acquired autoimmune disease, is characterized by immune-mediated platelet destruction. A biomarker is a biological entity that contributes to disease pathogenesis and reflects disease activity. Metabolic alterations are reported to be associated with the occurrence of various diseases. As metabolic biomarkers for ITP have not been identified. This study aimed to identify metabolism-related differentially expressed genes as potential biomarkers for pathogenesis of ITP using bioinformatic analyses.The microarray expression data of the peripheral blood mononuclear cells were downloaded from the Gene Expression Omnibus database (GSE112278 download link: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE112278 ). Key module genes were intersected with metabolism-related genes to obtain the metabolism-related key candidate genes. The hub genes were screened based on the degree function in the coytoscape sofware. The key ITP-related genes were subjected to functional enrichment analysis. Immune infiltration analysis was performed using a single-sample gene set enrichment analysis algorithm to evaluate the differential infiltration levels of immune cell types between ITP patient and control. Molecular subtypes were identified based on the expression of hub genes. The expression of hub genes in the ITP patients was validated using quantitative real-time polymerase chain reaction analysis. This study identified five hub genes (ADH4, CYP7A1, CYP1A2, CYP8B1, and NR1H4), which were be associated with the pathogenesis of ITP, and two molecular subtypes of ITP. Among these hub genes, CYP7A1 and CYP8B1 involved in cholesterol metabolism,were further verified in clinical samples.

Autoimmune cytopenia and Kabuki syndrome in paediatrics: Insights in 11 patients.

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives.

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.

[Expression of MicroRNA-3162-3p in Different Clinical Stages of Children with Primary Immune Thrombocytopenia and Its Significance].

OBJECTIVE: To explore the expression of microRNA-3162-3p in different clinical stages of childhood primary immune thrombocytopenia (ITP) and its significance. METHODS: Ninety-six children with ITP were enrolled and divided into new diagnosis group (n=40), persistent group (n=30) and chronic group (n=26) according to the course of disease. 80 healthy children were selected as the control group. Peripheral blood mononuclear cells (PBMNC) of ITP children and healthy children were isolated and cultured, and the expression of microRNA-3162-3p in PBMNC of subjects was detected by real-time fluorescence quantitative PCR. The contents of IL-17, IL-23, IL-10 and TGF-ß in PBMNC of subjects were determined by ELISA. The correlation between microRNA-3162-3p and platelet count, IL-17, IL-23, IL-10 and TGF-ß was analyzed. RESULTS: Compared with the control group, the expression of microRNA-3162-3p and IL-10 in PBMNC and platelet count of ITP children were significantly decreased（P < 0.05）, while IL-17, IL-23 and TGF-ß were significantly increased (P < 0.05). With the prolongation of the disease course, the expressions of microRNA-3162-3p and IL-10 in PBMNC and platelet count were significantly decreased（P < 0.05）, while the expressions of IL-17, IL-23 and TGF-ß were significantly increased (P < 0.05). The expression of microRNA-3162-3p in PBMNC was positively correlated with platelet count and IL-10 (r =0.716, 0.667), and negatively correlated with IL-17, IL-23, and TGF-ß (r =-0.540, -0.641, -0.560). CONCLUSION: MicroRNA-3162-3p expression is significantly reduced in PBMNC of children with ITP, and is involved in the regulation of Th17/Treg imbalance, which can be used as a potential therapeutic target of ITP.

E3 ubiquitin ligase casitas B-lineage lymphoma-b modulates T-cell anergic resistance via phosphoinositide 3-kinase signaling in patients with immune thrombocytopenia.

BACKGROUND: The E3 ubiquitin ligase casitas B-lineage lymphoma-b (CBLB) is a newly identified component of the ubiquitin-dependent protein degradation system and is considered an important negative regulator of immune cells. CBLB is essential for establishing a threshold of T-cell activation and regulating peripheral T-cell tolerance through various mechanisms. However, the involvement of CBLB in the pathogenesis of immune thrombocytopenia (ITP) is unknown. OBJECTIVES: We aimed to investigate the expression and role of CBLB in CD4+ T cells obtained from patients with ITP through quantitative proteomics analyses. METHODS: CD4+ T cells were transfected with adenoviral vectors overexpressing CBLB to clarify the effect of CBLB on anergic induction of T cells in patients with ITP. DNA methylation levels of the CBLB promoter and 5' untranslated region (UTR) in patient-derived CD4+ T cells were detected via MassARRAY EpiTYPER assay (Agena Bioscience). RESULTS: CD4+ T cells from patients with ITP showed resistance to anergic induction, highly activated phosphoinositide 3-kinase-protein kinase B (AKT) signaling, decreased CBLB expression, and 5' UTR hypermethylation of CBLB. CBLB overexpression in T cells effectively attenuated the elevated phosphorylated protein kinase B level and resistance to anergy. Low-dose decitabine treatment led to significantly elevated levels of CBLB expression in CD4+ T cells from 7 patients showing a partial or complete response. CONCLUSION: These results indicate that the 5' UTR hypermethylation of CBLB in CD4+ T cells induces resistance to T-cell anergy in ITP. Thus, the upregulation of CBLB expression by low-dose decitabine treatment may represent a potential therapeutic approach to ITP.

Mendelian randomization analysis reveals causality of inflammatory bowel disease on risks of Henoch-Schönlein purpura and immune thrombocytopenia.

BACKGROUND: Emerging clinical evidence has been discovered associating Inflammatory bowel disease (IBD) with Henoch-Schönlein purpura (HSP) and immune thrombocytopenia (ITP). However, it is unclear whether a cause-effect relationship exists between them. We aimed to examine the casual effect of IBD on the risk of HSP and ITP. METHODS: Based on summary statistics from International IBD Genetics (IIBDG) Consortium and FinnGen study, a two-sample Mendelian randomization study was carried out to determine whether IBD including ulcerative colitis (UC) and Crohn's disease (CD) is causally related to HSP, ITP or secondary thrombocytopenia. To support the results, a variety of sensitivity analyses were performed. RESULTS: Significant causal relationships between IBD and HSP (odds ratios = 1.20, 95% confidence interval: 1.07-1.36, adjusted P = 0.006) and ITP (odds ratios =1.22, 95% confidence interval: 1.08-1.38, adjusted P = 0.006) were found. Both genetically predicted UC and CD were positively related with ITP, while CD alone may be responsible for the higher risk of HSP. Besides, no significant association was observed between IBD and secondary thrombocytopenia. CONCLUSIONS: The results of this Mendelian randomization study supported the causal association of IBD with HSP and ITP. Taken together, our findings may present implications for management of IBD.

Lipoprotein lipids and apolipoproteins in primary immune thrombocytopenia: Results from a clinical characteristics and causal relationship verification, potential drug target identification by Mendelian randomization analyses.

Primary immune thrombocytopenia (ITP) is an acquired autoimmune disease. Cellular and systemic lipid metabolism plays a significant role in the regulation of immune cell activities. However, the role of lipoprotein lipids and apolipoproteins in ITP remains elusive. The automatic biochemistry analyser was used to measure the levels of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (apoA-I), apoB, apoE and lipoprotein a [LP(a)]. Genetic variants strongly associated with circulating lipoprotein lipids and apolipoproteins (LDL-C, apoB, TG, HDL-C and apoA-I) were extracted to perform Mendelian randomization (MR) analyses. Finally, drug-target MR and passive ITP mice model was used to investigate the potential druggable targets of ITP. Levels of HDL-C, apoA-I, decreased and LP(a) increased in ITP patients compared with healthy controls. Low HDL-C was causally associated with ITP susceptibility. Through drug-target MR and animal modelling, ABCA1 was identified as a potential target to design drugs for ITP. Our study found that lipid metabolism is related to ITP. The causative association between HDL-C and the risk of ITP was also established. The study provided new evidence of the aetiology of ITP. ABCA1 might be a potential drug target for ITP.

Regulatory role of ceRNA network in B lymphocytes of patients with immune thrombocytopenia.

OBJECTIVE: High-throughput sequencing was used to screen expressing differences of miRNA, lncRNA, and mRNA in CD19+ B peripheral blood samples of newly diagnosed immune thrombocytopenia (ITP) patients and healthy controls. The study aimed to explore the regulatory role of ceRNA network in the pathogenesis of dysfunctional CD19 + B lymphocytes of ITP patients. METHODS: CD19+ B lymphocytes were isolated from peripheral blood samples of ITP patients and their healthy counterparts. High-throughput sequencing was used to screen for the expression of miRNA, lncRNA, and mRNA of ITP patients and healthy controls, which were analysed by the ceRNA network. Moreover, qPCR was used to verify the differential expression of miRNA, lncRNA, and mRNA in ITP patients and healthy controls. The correlation between differentially expressed miRNA, lncRNA, mRNA, and B lymphocyte subsets was also analysed. RESULTS: The CD19+ B lymphocytes of 4 newly diagnosed ITP patients and 4 healthy controls were sequenced and analysed. There were 65 differentially expressed lncRNA and 149 mRNA forming a ceRNA network showed that 12 lncRNA and 136 differentially expressed mRNA were closely associated. Similarly, miR-144-3p, miR-374c-3p, and miR-451a were highly expressed in ITP patients, as confirmed by qPCR, which was consistent with the high-throughput sequence results. LOC102724852 and CCL20 were highly expressed in ITP patients, while LOC105378901, LOC112268311, ALAS2, and TBC1D3F were not as compared to healthy controls, which was consistent with the high-throughput sequence results. In addition, the expression of miR-374c-3p, LOC112268311, LOC105378901, and CXCL3 were correlated with the percentage of B lymphocyte subsets. CONCLUSIONS: The ceRNA network of miRNA, lncRNA, and mRNA in peripheral CD19 + B lymphocytes plays an essential role in the pathogenesis of ITP.

Analysis of clinical characteristics and treatment efficacy in two pediatric cases of ANKRD26-related thrombocytopenia.

ANKRD26-related thrombocytopenia (ANKRD26-RT or THC2, MIM 188 000), an autosomal dominant thrombocytopenia, is unresponsive to immunosuppressive therapy and susceptible to hematological malignancies. A large number of pediatric patients are diagnosed with immune thrombocytopenia (ITP) every year; however, thrombocytopenia of genetic origin is often missed. Extensive characterization of ANKRD26-RT will help prevent missed diagnosis and misdiagnosis. Furthermore, identification of ANKRD26-RT will help in the formulation of an accurate diagnosis and a treatment plan. In our study, we report cases of two Chinese pediatric patients with ANKRD26-RT and analyze their clinical characteristics, gene mutations, and treatment modalities. Both patients were 1-year-old and presented with mild bleeding (World Health Organization(WHO) score grade 1), different degrees of platelet reduction, normal mean platelet volume, and megakaryocyte maturation impairment not obvious. Genetic tests revealed that both patients had ANKRD26 gene mutations.Patient 1 had a mutation c.-140C>G of the 5' untranslated region (UTR), and patient 2 had a mutation of c.-127A>T of 5'UTR. Both patients were treated with eltrombopag, and the treatment was no response, with no adverse reactions.

What is the background? ANKRD26-RT is an autosomal dominant thrombocytopenia which is unresponsive to immunosuppressive therapy and susceptible to hematological malignancies.It is rare and lacks specific clinical features, making misdiagnosis easy.Some studies report that eltrombopag is safe and effective for short-term treatment of the disease; however, these reports are limited.What we did and summary of findings. We retrospectively studied the clinical manifestations and diagnosis process of ANKRD26-RT and discussed the treatment efficacy of immunosuppressants and eltrombopag for its management.We found two pediatric cases of patients with ANKRD26-RT with varying degrees of thrombocytopenia, mild bleeding, normal mean platelet volume, and megakaryocyte maturation impairment that was not obvious. Immunosuppressant treatment wasunresponsiveor temporarily responsivebut not sustained , and short-term administration of eltrombopag (25 mg/day) was safe, but it did not effectively improve the patients' platelet counts.What is the impact? If patients clinically diagnosed with immune thrombocytopenia do not respond  to immunosuppressive agents, genetic testing should be conducted to exclude hereditary thrombocytopenia, and a normal mean platelet volume should not exclude the possibility of the disease.For patients with ANKRD26-RT, eltrombopag is safe for short-term use;however, 25 mg/day treatment is unresponsive.Ourreport complements data on the diagnosis and management of ANKRD26-RT disease in children.

Evaluating the prevalence of inborn errors of immunity in adults with chronic immune thrombocytopenia or Evans syndrome.

Inborn errors of immunity (IEIs) are monogenic disorders that predispose patients to immune dysregulation, autoimmunity, and infection. Autoimmune cytopenias, such as immune thrombocytopenia (ITP) and Evans syndrome (a combination of ITP and autoimmune hemolytic anemia), are increasingly recognized phenotypes of IEI. Although recent findings suggest that IEIs may commonly underlie pediatric ITP and Evans syndrome, its prevalence in adult patients with these disorders remains undefined. This study sought to estimate the prevalence of underlying IEIs among adults with persistent or chronic ITP or Evans syndrome using a next-generation sequencing panel encompassing >370 genes implicated in IEIs. Forty-four subjects were enrolled from an outpatient adult hematology clinic at a tertiary referral center in the United States, with a median age of 49 years (range, 20-83). Fourteen subjects (31.8%) had secondary ITP, including 8 (18.2%) with Evans syndrome. No cases of IEI were identified despite a high representation of subjects with a personal history of autoimmunity (45.5%) and early onset of disease (median age at diagnosis of 40 years [range, 2-77]), including 20.5% who were initially diagnosed as children. Eight subjects (18.2%) were found to be carriers of pathogenic IEI variants, which, in their heterozygous state, are not disease-causing. One case of TUBB1-related congenital thrombocytopenia was identified. Although systematic screening for IEI has been proposed for pediatric patients with Evans syndrome, findings from this real-world study suggest that inclusion of genetic testing for IEI in the routine work-up of adults with ITP and Evans syndrome has a low diagnostic yield.

The role of genetics in refractory immune thrombocytopenia.

Patients with refractory immune thrombocytopenia (rITP) have increased morbidity and mortality. Currently, there is limited understanding of the cause of refractoriness and no markers to help direct novel treatment options. Understanding the reason(s) for refractoriness is crucial to determining novel treatment options. The pathogenesis underlying rITP has generally been thought to be an underlying genetic predisposition with an environmental trigger. Familial ITP remains rare, and there are few twin studies, suggesting that a simple genetic cause is unlikely. However, genetic mutations provide the background for several autoimmune diseases. In this review, we explore the evidence of either an inherited genetic cause of rITP or an acquired mutation, in particular one resulting in clonal expansion of cytotoxic T cells.

Treatment of immune thrombocytopenia with hetrombopag olamine tablets in a Kabuki syndrome patient with new KMT2D mutations.

Kabuki syndrome (KS) is a rare multisystem-affecting genetic disorder, and usually accompanied with autoimmune disorders such as immune thrombocytopenic purpura (ITP). Here, we report a 16-year-old patient with Kabuki syndrome with ITP and observe the therapeutic effect of TPO agonist hetrombopag olamine tablets. The duration of maintenance therapy and follow up were both 17 months. Whole exon sequencing (WES) of the patient's peripheral blood showed c.5775_5778del (p. Leu1926LysfsTer120) heterozygous mutation in the KMT2D gene, which was not reported before.

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.

The mTORC1 pathway participate in hyper-function of B cells in immune thrombocytopenia.

B cell hyper-function plays an important role in the pathogenesis of immune thrombocytopenia (ITP), but the molecular mechanisms underlying such changes remain unclear. We sought to identify regulators of B cell dysfunction in ITP patients through transcriptome sequencing and the use of inhibitors. B cells were isolated from PBMC of 25 ITP patients for B cell function test and transcriptome sequencing. For the potential regulatory factors identified by transcriptome sequencing, the corresponding protein inhibitors were used to explore the regulatory effect of the regulatory factors on B cell dysfunction in vitro. In this study, increased antibody production, enhanced terminal differentiation and highly expressed costimulatory molecules CD80 and CD86 were found in B cells of patients with ITP. In addition, RNA sequencing revealed highly activated mTOR pathway in these pathogenic B cells, indicating that the mTOR pathway may be involved in B cell hyper-function. Furthermore, mTOR inhibitors rapamycin or Torin1 effectively blocked the activation of mTORC1 in B cells, resulting in reduce antibody secretion, impaired differentiation of B cells into plasmablasts and downregulation of costimulatory molecules. Interestingly, as an unspecific inhibitor of mTORC2 besides mTORC1, Torin1 did not show a stronger capacity to modulate B cell function than rapamycin, suggesting that the regulation of B cells by Torin1 may depend on blockade of mTORC1 rather than mTORC2 pathway. These results indicated that the activation of mTORC1 pathway is involved in B cell dysfunction in patients with ITP, and inhibition of mTORC1 pathway might be a potential therapeutic approach for ITP.

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.

Long non-coding RNA maternally expressed gene 3, miR-125a-5p, CXCL13, and NF-kB in patients with immune thrombocytopenia.

The main aim of this study was to assess the expression level of circulating long non-coding RNA maternally expressed gene 3 (lncRNA-MEG3), microRNA (miR-125a-5P), the chemokine C-X-C motif ligand13 (CXCL13), and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) in immune thrombocytopenia (ITP) cases and to study its relation to the disease severity and treatment response. This case-control study included 45 patients newly diagnosed as ITP and 45 healthy subjects. We assessed complete blood count, antinuclear antibodies, hepatitis B and C virus serology, lncRNA-MEG3, miR-125a-5P, and CXCL13 expression in serum by real-time PCR and NF-kb protein by ELISA. In ITP patients compared to control, lncRNA-MEG3 was significantly increased, and miRNA-125a-5P was decreased, and this was associated with higher CXCL13 and NF-kB levels (P < 0.001, for all).There was a significant negative correlation between platelet count and lncRNA-MEG3, CXCL13, and NF-kb, while a positive correlation with miR-125a-5p in ITP patients. Patients who responded to steroids had significantly higher miR-125a-5p (P = 0.016) and significantly lower lncRNA-MEG3 (P < 0.001), CXCL13 (P = 0.005), and NF-kb (p = 0.002). Based on the ROC curves, lncRNA-MEG3 displayed the highest area under the curve (AUC) in the identification of organ bleeding (AUC = 0.805), the response to steroids (AUC = 0.853), and the need for splenectomy (AUC = 0.75).

Deciphering the genetic basis of immune thrombocytopenia: current evidence for genetic predisposition in adult ITP.

Immune thrombocytopenia (ITP) is the consequence of a complex, still incompletely understood immunological dysregulation. Proposed mechanisms include autoantibody-induced platelet destruction, impaired platelet production as well as abnormalities in T-cell immunity, such as T helper cells (Th1) polarization, a high proportion of Th17 cells, and a reduced number of regulatory T cells. Although the etiology of ITP is incompletely understood and considered multifactorial in most cases, genetic variants are thought to play a key role in susceptibility to ITP, especially in persistent or chronic ITP. Efforts are currently underway to uncover possible predisposing genetic factors for the development of ITP. Single-nucleotide polymorphisms and copy number variations have been identified in several immune-related genes, such as cytokine genes, Fcγ receptor genes or T-cell costimulation genes, and have been associated with patients' susceptibility to ITP. However, because of the clinical heterogeneity and low incidence of ITP it remains challenging to perform genetic analyses with sufficiently large sample size within informative patient populations, highlighting the need for collection of well-annotated biomaterials in clinical trials or registry projects. Another significant challenge is to go beyond performing association studies alone and to establish genotype-phenotype associations, thus proving causality between a genetic alteration and ITP pathogenesis. This review summarizes our current knowledge on genetic alterations identified as potential predisposing factors for the development of ITP in adults, thereby addressing signaling pathways considered critical for ITP pathogenesis.