Multi-dysfunctional pathophysiology in ITP

Immune thrombocytopenia secondary to primary cytomegalovirus infection after renal transplantation treated with a thrombopoietin receptor agonist: a case report

BACKGROUND

Immune thrombocytopenia (ITP) is an acquired disorder characterised by a low platelet count due to immune-mediated destruction and impaired platelet production. Here we report a rare case of primary cytomegalovirus (CMV) infection followed by thrombocytopenia after renal transplantation (RT).

CASE PRESENTATION

A 24-year-old male patient with end-stage kidney disease secondary to hereditary focal segmental glomerulosclerosis was treated with peritoneal dialysis and received ABO-compatible living-related RT from his aunt. Nine months after the RT, the patient was diagnosed with primary CMV infection. After initiating treatment for primary CMV infection, the patient developed thrombocytopenia. After excluding other diseases or drugs that may cause thrombocytopenia, the patient was finally diagnosed with ITP, administered prednisolone (PSL), and started on Helicobacter pylori eradication therapy. Tapering the PSL dose was difficult, but thrombopoietin receptor agonists (TPO-RAs) were effective.

CONCLUSIONS

In this case, the patient was diagnosed with ITP, and other causes of thrombocytopenia after RT were successfully ruled out. This case report demonstrates that RT recipients can develop ITP after CMV infection, and, in such cases, TPO-RAs may be an attractive option as a second-line therapy.

Upregulation of necroptosis markers RIPK3/MLKL and their crosstalk with autophagy-related protein Beclin-1 in primary immune thrombocytopenia

Necroptosis is a novel form of programmed necrotic cell death involved in various autoimmune diseases. The potential role of necroptosis in primary immune thrombocytopenia (ITP) and the possible interlink with autophagy have not been fully investigated. The gene expression of mixed lineage kinase-like domain (MLKL), receptor-interacting protein kinase 3 (RIPK3) and Beclin-1 were quantified in peripheral blood of 45 ITP patients and 20 healthy controls. Their associations with clinical, laboratory parameters and response to steroid therapy in ITP patients were evaluated. RIPK3, MLKL, and Beclin-1 were significantly upregulated in ITP patients than in healthy controls (P < 0.001). Beclin-1 mRNA levels were positively correlated with both RIPK3 and MLKL mRNA levels in ITP patients (P < 0.0001). In addition, MLKL, RIPK3, and Beclin-1 mRNA levels were inversely correlated with platelet count (r = -0.330, -0.527 and -0.608, respectively). On the hand, positive correlations between MLKL (P = 0.01), RIPK3 (P = 0.005), Beclin-1 (P = 0.002) mRNA levels and severity of bleeding in ITP patients were reported. Steroid responders (n = 18, 40%) had significantly lower MLKL, RIPK3, Beclin-1 mRNA expression levels than their levels in the non-responders (n = 27, 60%). Necroptosis may play a critical role in the pathogenesis of ITP and provide both novel therapeutic targets and promising biomarkers for the prediction of bleeding severity and treatment response in ITP patients. Additionally, this study highlighted the crosstalk between autophagy and necroptosis in ITP patients.

Regulatory factors involved in Th17/Treg cell balance of immune thrombocytopenia

Immune thrombocytopenia is a common heterogeneous autoimmune disease that is characterized by decreasing peripheral blood platelet counts and increasing risk of bleeding. Studies have shown that an imbalance between T helper 17 (Th17) and Regulatory T (Treg) cells differentiated from CD4+T-cells is a key factor influencing the development and pathogenesis of immune thrombocytopenia. Th17 cells promote the development of chronic inflammatory disorders and induce autoimmune diseases, whereas Treg cells regulate immune homeostasis and prevent autoimmune diseases. Several regulators affecting the production and maintenance of these cells are also essential for proper regulation of Th17/Treg balance; these regulatory factors include cell surface proteins, miRNAs, and cytokine signaling. In this review, we focus on the function and role of balance between Th17 and Treg cells in immune thrombocytopenia, the regulatory factors, and therapeutic goals of this balance in immune thrombocytopenia.

Pathological Background and Clinical Procedures in Oral Surgery Haemostasis Disorders: A Narrative Review

Haemostasis disorders are serious pathologies that could put dental and surgical procedures at risk as they are associated with postoperative bleeding, which in some circumstances could be prolonged and dangerous for the patient. In-depth knowledge of the problems associated with coagulation pathologies and the suitable specific procedures should be implemented in dental practice. A good awareness of the clinical protocols to be used in these circumstances may help reduce operator stress and increase patient compliance. Collaboration with the haematologist is always recommended to establish an adequate treatment plan, both regarding the administration of therapies that promote haemostasis and for assessing the operative risk. Hereby, we summarize the congenital and hereditary pathologies that lead to haemostasis disorders, which can be found in patients undergoing dental procedures. The purpose of this narrative review is to frame the diseases from a clinical, anamnestic, and etiopathological standpoint, as well as to evaluate an operative approach to the pathology under consideration, with particular attention to anaesthesia manoeuvres and post-surgical haemostasis, to avoid hematoma formation and uncontrolled bleeding which can lead procedure failure up and even death. Of note, it is likewise important to educate the patient about prevention, to keep the oral cavity healthy and avoid invasive procedures, limiting the number of operative sessions.

Expression of B-cell activating factor in pediatric patients with immune thrombocytopenia: a single institutional series and review of literature

B-cell-activating factor (BAFF) is a crucial cytokine supporting survival and differentiation of B cells. Dysregulation of BAFF is involved in the pathogenesis of B-cell related autoimmune diseases including immune thrombocytopenia (ITP). The aim of this study was to evaluate the significance of BAFF expression in pediatric ITP patients. Eighty pediatric patients with ITP are subdivided in three groups. Group I included (32 patients) diagnosed with acute ITP less than 3 months, group II (48 patients) diagnosed with persistent ITP (from 3 to 12 months) and chronic ITP (more than 12 months) and group III 20 healthy controls. Complete blood picture, autoimmune profile, antiplatelet antibodies, coagulation profile, bone marrow examination, and RT-PCR were performed to detect the expression for BAF for all participants in this study. BAFF expression levels significantly increased in cases rather than in controls. BAFF Expression Value significantly increased in groups I & II (3.10 ± 1.99&3.29 ± 2.58) compared to controls (0.83 ± 0.45) as p < .001 for both. On the other hand, groups I & II were comparable in BAFF Expression Value (p = .470). BAFF expression increased in ITP patients, implying a function in the disease's pathogenesis.

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.

The presence of idiopathic thrombocytopenic purpura and incidence of acute non-ST elevation myocardial infarction

Platelets play an integral role in the pathogenesis of acute coronary syndrome (ACS). The purpose of this study was to investigate any correlation between immune thrombocytopenia (ITP) and non-ST segment elevation myocardial infarction (NTSEMI), a common presentation of ACS. Using the large Nationwide Inpatient Sample (NIS) database, we studied any correlation between NSTEMI and ITP utilizing ICD-9 codes. We performed uni- and multivariate analysis adjusting for risk factors from the years 2002-2011. Data was extracted from 106,653 ITP patients and 79,636,090 controls. In multiple years of the study period (2002-2011), NSTEMI incidence was significantly higher in ITP patients when compared with non-ITP patients in the univariate analysis (odds ratio average 1.226). However, no significant association was found after adjusting for additional risk factors in multivariate analysis. Based on our large database study, ITP is not independently associated with NSTEMI incidence after adjusting for comorbidity.

Elucidating the Mechanism of Action of the Attributed Immunomodulatory Role of Eltrombopag in Primary Immune Thrombocytopenia: An In Silico Approach

Eltrombopag is a thrombopoietin receptor (MPL) agonist approved for the treatment of primary immune thrombocytopenia (ITP). Recent evidence shows that some patients may sustain platelet counts following eltrombopag discontinuation. The systemic immunomodulatory response that resolves ITP in some patients could result from an increase in platelet mass, caused either by the direct action of eltrombopag on megakaryocytes through MPL stimulation, or potential MPL-independent actions on other cell types. To uncover the possible mechanisms of action of eltrombopag, in silico analyses were performed, including a systems biology-based approach, a therapeutic performance mapping system, and structural analyses. Through manual curation of the available bibliography, 56 key proteins were identified and integrated into the ITP interactome analysis. Mathematical models (94.92% mean accuracy) were obtained to elucidate potential MPL-dependent pathways in non-megakaryocytic cell subtypes. In addition to the effects on megakaryocytes and platelet numbers, the results were consistent with MPL-mediated effects on other cells, which could involve interferon-gamma, transforming growth factor-beta, peroxisome proliferator-activated receptor-gamma, and forkhead box protein P3 pathways. Structural analyses indicated that effects on three apoptosis-related proteins (BCL2L1, BCL2, BAX) from the Bcl-2 family may be off-target effects of eltrombopag. In conclusion, this study proposes new hypotheses regarding the immunomodulatory functions of eltrombopag in patients with ITP.

Association of FOXP3 gene polymorphisms with chronic immune thrombocytopenia in a Chinese Han population

INTRODUCTION

Forkhead box P3 (Foxp3) is encoded by the human FOXP3, an X-chromosome gene, and is a transcription factor that regulates regulatory T-cell (Treg) development and function. FOXP3 gene polymorphisms have recently been investigated as candidate risk factors in various autoimmune diseases. This study aimed to investigate the possible influence of FOXP3 gene polymorphisms on genetic predisposition to chronic immune thrombocytopenia (ITP).

METHODS

The study cohort comprised 329 chronic ITP patients and 279 healthy controls, who were genotyped for three polymorphisms in the promoter region of FOXP3 gene, -6054 del/ATT, -3279 A/C, and -924 A/G.

RESULTS

Of the three polymorphisms identified, the -3279 AA genotype was more frequent in female patients with chronic ITP than in female controls (P = .035, OR 0.434, 95% CI 0.223-0.846), and the -3279 A carrier was shown to be associated with the risk of chronic ITP in female cohort (P = .003, OR 0.610, 95% CI 0.437-0.851). Furthermore, the female patients with chronic ITP had remarkably more frequent haplotype -6054 del/-3279 A/-924 A (P = .027, OR 3.584, 95% CI 1.148-11.186) and less haplotype -6054 del/-3279 C/-924 G (P = .039, OR 0.445, 95% CI 0.204-0.973) in comparison with female healthy controls. Although there were no significant differences in the male cohort, when the combined alleles and haplotypes of the two genders were analyzed, the results obtained were similar to those of females.

CONCLUSION

According to our data, the -3279 A/C polymorphism of FOXP3 gene may be associated with the susceptibility to chronic ITP in Chinese Han population.

Patient characteristics when starting treatment and patterns of treatment in adults with chronic immune thrombocytopenia

: Asymptomatic patients with primary chronic immune thrombocytopenia (ITP) are not recommended treatment if their platelet counts are above 30 × 10/l. Factors such as age and comorbidities may influence clinical manifestations and should be considered for treatment decisions. The aim of this study was to determine the impact of clinical characteristics for initiation of ITP treatment, and the patterns of ITP treatment given. We performed an observational cohort study in Sweden with information from medical records and National Health Registers. Adults diagnosed with incident primary ITP between years 2009 and 2016 were included. Multinomial logistic regression was used to assess the impact of factors predicting treatment start. Out of 858 patients with chronic ITP from 71 hospitals we identified 585 (68%) with a first ITP treatment. For 537 (92%) corticosteroids were the first choice. The median platelet counts at start of treatment was 12 × 10/l (interquartile range 5-27 × 10/l). The variables predicting treatment start were platelet counts below 20 × 10/l and treatment with antihypertensive drugs. Patients with diabetes were less likely to receive corticosteroids. Severe bleeding occurred in 75 (13%) of the patients. Platelet counts below 20 × 10/l, antihypertensive treatment and bleedings were the strongest predictors of treatment start, diabetes yielded lower odds to start corticosteroid treatment. The majority of the patients had corticosteroids as first treatment while second treatment was diverse. Asymptomatic thrombocytopenia is not considered a reason as such for initiating treatment. In the latter years, splenectomy seemed to occur later in the course of treatment.

Importance of Th22 Cell Disequilibrium in Immune Thrombocytopenic Purpura

BACKGROUND The disequilibrium of T helper (Th) cells play an important role in the occurrence and development of immune thrombocytopenic purpura (ITP). Th22 cells, as a newly discovered subset of T lymphocytes, plays an important role in autoimmune disorders and inflammatory diseases. MATERIAL AND METHODS This study explored the role of different lymphocyte subsets in chronic ITP. To explore the value of Th22 cells in the diagnosis of ITP, the numbers of Th1, Th17, and Th22 cells were detected by a 4-color flow cytometric in 32 chronic ITP patients and 30 healthy controls. RESULTS Our data showed that, compared with healthy controls, the numbers of circulating Th1, Th17, and Th22 (p<0.05) cells increased significantly in ITP patients, and Th22 cells were correlated positively with Th1 cells (r=0.4041, p<0.01) and Th17 cells (r=0.4637, p<0.05). Moreover, a positive relationship was found between Th1/Th22 cells and Th1 cells (r=0.7696, p<0.001). CONCLUSIONS A disequilibrium expression profile of Th22 cells in peripheral blood was associated with pathogenesis of ITP, possibly through cooperatively working with Th17 and Th1, which may provide a novel approach for diagnosis of ITP.

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.

The association between idiopathic thrombocytopenic purpura and cardiovascular disease: a retrospective cohort study

Essentials We estimated the cardiovascular risk of patients with idiopathic thrombocytopenic purpura (ITP). The risk of cardiovascular disease was 38% higher in ITP patients compared with controls. Among the ITP patients, splenectomy was associated with higher cardiovascular disease. Clinicians should consider cardiovascular risk when managing ITP patients.

SUMMARY

Background Idiopathic thrombocytopenic purpura (ITP) is classically characterized by a transient or persistent decrease of platelet count. Mortality is higher in the ITP population than the general population, with a possible association with increased cardiovascular disease (CVD). Objectives The objective was to assess the strength of the association between ITP and CVD, with a secondary aim to assess the impact of splenectomy on CVD. Methods A population-based retrospective, open cohort study using clinical codes was performed using data from 6591 patients with ITP and 24 275 randomly matched controls (up to 1:4 ratio matched by age, sex, body mass index and smoking status). The main outcome was the risk of CVD, which included ischemic heart disease, stroke, trans-ischemic attack and heart failure. Adjusted incidence rate ratios were calculated using Poisson regression. Results During a median 6-year observation period there was a CVD diagnosis recorded in 392 (5.9%) ITP patients and 1114 (4.5%) control patients. There was an increased risk of developing CVD in the ITP cohort (incidence rate ratio [IRR], 1.38; 95% confidence interval [CI], 1.23-1.55), which remained robust even after a sensitivity analysis only including incident cases of ITP. Findings suggested that patients who had undergone splenectomy were at even further increased risk of developing CVD when compared with the ITP population who had not undergone splenectomy (adjusted IRR, 1.69; 95% CI, 1.22-2.34). Conclusion There is an increased risk of developing CVD in patients with ITP and even further increased risk for those patients with ITP who underwent splenectomy.

Pharmacological agents preceding a diagnosis of immune thrombocytopenia in adult patients developing the chronic form: A Swedish national register study

Patients with primary chronic immune thrombocytopenia (cITP) have been reported to use more anti-infective medications, even before diagnosis of immune thrombocytopenia (ITP). The more common use of anti-infective medications may be due to general health problems, requiring medication in the early stages of cITP and before the diagnosis is set, rather than infections preceding the disease. Accordingly, cITP may not only be associated with use of anti-infective medications but also with medications for more general symptoms.

OBJECTIVE

To investigate use of medications for general symptoms, such as analgesics and vitamin supplements in patients with ITP developing the chronic form, the year preceding their first primary diagnosis in comparison with such use in the general population.

METHOD

Swedish Health Registers were used to identify adult patients (n=1087) with primary cITP during 2006-2012 and data on medications. Standardized Incidence Ratios (SIRs) and 95% confidence intervals (CI), were estimated as a measure of relative risk.

RESULTS

The association for overall studied medications was SIR=1.36 (95% CI 1.32-1.41). A majority of the point estimates were above unity.

CONCLUSION

In patients with cITP, prescription fills for medications used to treat pain conditions and vitamin deficiencies are more common in the year preceding their first diagnosis as compared with prescription fills in the general population. Our results suggest that patients later diagnosed with cITP receive treatment due to symptoms that could be signs of an early ITP. Accordingly, in investigations for unspecific pain symptoms and vitamin deficiencies, cITP should be considered as a differential diagnosis.

The potential association of tumor necrosis factor-βeta (252 G/A) cytokine gene polymorphism with immune thrombocytopenic purpura among Egyptian children

OBJECTIVES

The main objective of this study was to study tumor necrosis factor beta (TNFB) + 252G/A gene polymorphism, known to be related to autoimmunity, in immune thrombocytopenia (ITP) patients. We also aimed to investigate the association between TNFB + 252G/A polymorphism and susceptibility to develop persistent/chronic ITP.

METHODS

One hundred pediatric ITP patients, as well as 50 age- and sex-matched healthy Egyptian subjects, were included. Genotyping of TNF-β gene (G252A) was done using the PCR-RFLP method.

RESULTS

TNFB allele B2 frequency was (64%, 64/100) in controls, (69%, 138/200) in ITP patients, while the frequency of the variant allele B1 was 36% (36/100) in controls, (31%, 62/200) in ITP patients. TNFB genotype frequency in ITP patients showed equal frequency for B2B2 and B1B2 genotypes, (46%, 46/100), while B1B1 frequency was 8% (8/100). Among controls, frequencies of B2B2, B1B2 and B1B1 genotypes were 36% (18/50), 56% (28/50), and 8% (4/50), respectively. Odds ratio for the risk of developing ITP revealed no statistically significant risk, associated with any allele or genotype. No association was encountered between different genotypes and age, hematological parameters, gender, stage of the disease or response to treatment.

DISCUSSION

Comparison between ITP patients and controls as regards TNFB allele and genotype frequencies showed no statistically significant difference. No increased risk for developing ITP was associated with any allele/genotype.

CONCLUSION

The risk of developing ITP was not related to the studied polymorphism.

Expression of CD markers' in immune thrombocytopenic purpura: prognostic approaches

Immune Thrombocytopenic Purpura (ITP) is a common autoimmune bleeding disorder characterized by a reduction in peripheral blood platelet counts. In this disease, autoantibodies (Auto-Abs) are produced against platelet GPIIb/GPIIIa by B cells, which require interaction with T cells. In this review, the importance of B and T lymphocytes in ITP prognosis has been studied. Relevant literature was identified by a PubMed search (1990-2016) of English-language papers using the terms B and T lymphocyte, platelet, CD markers and immune thrombocytopenic purpura. T and B lymphocytes are the main immune cells in the body. Defective function causes disrupted balance of different subgroups of lymphocytes, and abnormal expression of surface markers of these cells results in self-tolerance dysfunction, as well as induction of Auto-Abs against platelet glycoproteins (PG). Given the role of B and T cells in production of autoantibodies against PG, it can be stated that the detection of changes in CD markers' expression in these cells can be a good approach for assessing prognosis in ITP patients.

Differences in microbial metabolites in urine headspace of subjects with Immune Thrombocytopenia (ITP) detected by volatile organic compound (VOC) analysis and metabolomics

ITP is an organ-specific autoimmune disorder characterised by a low platelet count whose cause is uncertain. A possible factor is food intolerance, although much of the information linking this with ITP is anecdotal. The role of food intolerance in ITP was studied by replacing a normal diet with an elemental diet (E028), but this did not increase platelet counts. Clear differences, however, were apparent between the volatile organic compounds (VOCs) in the urine headspace of patients with ITP and those present in healthy volunteers, which leads to speculation that abnormal metabolic activity of the intestinal microbiome may be a factor causing ITP. However, further work is needed to confirm this. There were also differences between the VOCs of patients on a normal diet and those on the elemental diet, and in this case, the VOCs involved are very likely to be of bacterial origin, as their production is affected by dietary manipulation. Many of these VOCs are known to be toxic.

Abnormal Distribution and Function of Monocyte Subsets in Patients With Primary Immune Thrombocytopenia

Human monocytes are heterogeneous and play an important role in autoimmune diseases. However, the distribution and function of monocyte subsets remain unclear in primary immune thrombocytopenia (ITP). In this study, we determined the frequencies of monocyte subsets in 71 untreated patients with active ITP and 49 healthy controls by flow cytometry. Compared with controls, the frequency of nonclassical monocytes was significantly increased in patients with active ITP but decreased after complete remission. The intermediate subset was also increased in patients with active ITP and produced the highest levels of tumor necrosis factor α and interleukin 1β. Both the nonclassical and intermediate subsets were negatively correlated with the platelet counts. We further determined the correlation between monocyte subsets and the proliferation of platelet-autoreactive T cells. The purified monocyte subsets were cocultured with CD4+ T cells and autologous platelets. The nonclassical subset showed the highest capability of promoting platelet reactive T-cell proliferation and significantly promoted the secretion of interferon γ among the 3 subsets. In conclusion, the nonclassical and intermediate monocyte subsets are both expanded and play different roles in the pathogenesis of ITP.

CD16 and CD32 Gene Polymorphisms May Contribute to Risk of Idiopathic Thrombocytopenic Purpura

BACKGROUND Epidemiological studies have evaluated the associations of CD16 158F>V and CD32 131H>R gene polymorphisms with the risk of idiopathic thrombocytopenic purpura (ITP). MATERIAL AND METHODS Published studies on CD16 158F>V and CD32 131H>R polymorphisms with susceptibility to ITP were systematically reviewed until April 1, 2014. The Cochrane Library Database, Medline, CINAHL, EMBASE, Web of Science, and Chinese Biomedical Database (CBM) were used to search for relevant studies and then a meta-analysis was conducted by using Stata 12.0 software in order to produce consistent statistical results. RESULTS In total, 10 clinical case-control studies with 741 ITP patients and 1092 healthy controls were enrolled for quantitative data analysis. Results of this meta-analysis suggest that CD16 158F>V polymorphism had strong correlations with the susceptibility to ITP under 5 genetic models (all P<0.05). However, no similar associations were found between CD32 131H>R polymorphism and the susceptibility to ITP (all P>0.05). Subgroup analysis by ethnicity revealed that CD16 158F>V polymorphism was associated with the increased risk of ITP among both Caucasian and non-Caucasian populations. Nevertheless, no statistically significant correlations between CD32 131H>R polymorphism and the risk of ITP were observed among Caucasians and non-Caucasians (all P>0.05). CONCLUSIONS Our findings indicate that CD16 158F>V polymorphism may contribute to the increased risk of ITP, whereas CD32 131H>R polymorphism may not be an important risk factor for ITP.

Increased susceptibility to infections before the diagnosis of immune thrombocytopenia

BACKGROUND

Infections after diagnosis of primary chronic immune thrombocytopenia (cITP) have mostly been connected to the immunomodulation treatment. Infections may trigger autoimmune diseases and may be a complication of an already impaired immune system.

OBJECTIVES

To investigate the association of cITP with infection before diagnosis. We also estimated the incidence of cITP based on the new definition by the International ITP Working Group.

METHODS

We identified 1087 adults with primary cITP between 2006 and 2012 using the Swedish Patient Register. Data on infections not already associated with secondary ITP were also retrieved from the register. The standardized incidence ratios (SIRs), using the rates from the general population, and 95% confidence intervals (CIs) were estimated as a measure of relative risk. We used data from the Prescribed Drug Register to estimate SIR for anti-infective treatment.

RESULTS

The incidence of cITP was 2.30 per 100 000 person-years (95% CI, 2.15-2.45). cITP was associated with an increased risk of serious infections requiring inpatient or outpatient care within 5 years before cITP diagnosis (SIR = 8.74; 95% CI, 7.47-10.18). Higher magnitude SIRs were observed for candidiasis, viral infection at an unspecified site and acute upper respiratory infections. For anti-infective drugs the SIR was 1.37 (1.25-1.50) and the highest SIRs were observed for amoxicillin, macrolides, nitrofurantoin and antivirals.

CONCLUSION

Patients with cITP have increased risks of infection and anti-infective treatments before their cITP diagnosis, with a more marked risk for candidiasis and viral infections. The findings indicate that infection is not only related to the immunomodulation treatment but also to the disease itself.

Is There a Relationship Between CXCR4 Gene Expression and Prognosis of Immune Thrombocytopenia in Children?

Immune thrombocytopenia (ITP) is a common autoimmune disorder characterized by decreased platelet count (thrombocytopenia) and bleeding symptoms due to production of autoantibodies against platelets. Chemokines are molecules inducing chemotaxis and play an important role in megakaryopoiesis, including CXCR4 chemokine receptor. CXCR4 is expressed on cells of megakaryocytic series, especially platelets, and triggers several mechanisms in these cells. The purpose of this study was to evaluate the pattern of CXCR4 gene changes upon diagnosis and after treatment and its comparison with laboratory findings in peripheral blood samples from newly diagnosed ITP patients. 35 newly diagnosed patients with ITP and 35 healthy controls were enrolled in this study. CXCR4 gene expression was investigated before and after treatment using real-time PCR. HPRT gene was used as the reference gene to calculate the expression rate of CXCR4 as CXCR4/HPRT ratio. CXCR4 gene expression upon diagnosis and after treatment in peripheral blood plasma of ITP patients showed a significant decrease in comparison with the control group while its expression did not change before and after treatment. No significant correlation was found between the expression of this gene and laboratory parameters. Due to unpredictable course of ITP in patients and the possibility of its progress to refractory form, accurate choice of a biomarker is essential for evaluating prognosis and detection of resistant forms.

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

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

The effect of single course high dose dexamethasone on CD28/CTLA-4 balance in the treatment of patients with newly diagnosed primary immune thrombocytopenia

To evaluate the effect of a single course of high dose dexamethasone (HD-DXM) on CD28 and CTLA-4 expression in patients with newly-diagnosed primary immune thrombocytopenia (ITP). Twenty-8 ITP patients (18 females and 10 males, age range 18–65 years, median age 38.5 years) enrolled in this study and 26 healthy volunteers (19 women and 7 men, age range 16–66 years, median age 37 years) served as a control group. The patients were treated with HD-DXM (40 mg/day) for 4 consecutive days. CD28 and CTLA-4 expression was assessed by flow cytometry once-monthly for 6 months. Plasma levels of the cytokines IFN-γ and IL-10 were determined by enzyme-linked immunosorbent assay. One month after treatment, a platelet response was observed in 23 (82%) of the patients. The response rates over the next 5 months were 71%, 57%, 53%, 46%, and 39%, chronologically. We observed a significant decrease in CD28 expression after the first month (34.7 ± 4.8% vs. 44.5 ± 4.4% before treatment), after which the CD28 levels gradually increased. In contrast, CTLA-4 expression increased after the first month (3.2 ± 0.5% vs. 0.8 ± 0.4 before treatment), after which the CTLA-4 levels gradually decreased. Similar dynamic changes were seen in the levels of IFN-γ and IL-10. The dynamic changes of CD28 and CTLA-4 were consistent with those of IFN-γ and IL-10 and with the effectiveness of HD-DXM in the treatment of ITP. Our results suggest that a disturbed CD28/CTLA-4 balance may contribute to the immunopathogenesis of ITP.

[Efficacy and safety of rhTPO in the treatment of pediatric primary immune thrombocytopenia]

OBJECTIVE

To evaluate the efficacy and safety of recombinant human thrombopoietin (rhTPO) in treatment of pediatric primary immune thrombocytopenia (ITP).

METHODS

The clinical characteristics of 41 pediatric ITP patients who received rhTPO therapy from December 2006 to September 2014 were retrospectively analyzed (as rhTPO group). During the same time another 26 pediatric ITP patients who received vindesine combined with human immunoglobulin therapy were selected as control group. The treatment outcomes were evaluated.

RESULTS

A total of 67 cases of pediatric ITP, 31 males and 36 females with a median age 10.0(1.6-17.0) years were enrolled, including 19 cases of newly disgnosed ITP, 18 cases of persistent ITP and 30 cases of chronic ITP. Of them, 43 cases of whom were severe ITP (PLT<10×10⁹/L). The total response rate had no statistically significant difference between the rhTPO group and the control group (68.29% vs 65.38%, P=0.806), neither in newly ITP, persistent and chronic ITP (P=0.320, P=0.763). In severe ITP patients, 17 of 30 cases (56.67%) achieved response with rhTPO therapy, while the control group was 61.54% (8/13) (P=0.766). The median maximum peak of platelet counts and the time of the platelet counts >30×10⁹/L and > 50×10⁹/L had no statistically significant differences in rhTPO group compared with the control group [52(7-608)×10⁹/L vs 40(3-152)×10⁹/L, P=0.05; 7(3-13) d vs 4(2-24) d, P=0.202; 7.5(4-15) d vs 5.5(4-23) d, P=0.557]. The mean platelet counts were 43(3-605)×10⁹/L in the rhTPO group, which were higher than the control group [32(-14-149)×10⁹/L, P=0.042]. No severe adverse effects were observed in both groups.

CONCLUSION

For pediatric ITP, rhTPO has a similar outcomes with vindesine combined with human immunoglobulin, and it is an effective and safe treatment option.

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.

STAT1 single nucleotide polymorphisms and susceptibility to immune thrombocytopenia

Primary immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder. One of the key mediators of IFN-γ signaling is the signal transducer and activator of transcription 1 protein (STAT1). We evaluated the relationship between STAT1 gene single nucleotide polymorphisms (SNPs) and the associated risk of ITP in a prospective case-control study. A total of 548 children were recruited: 328 children with ITP and 220 healthy children as sex- and age-matched normal controls. The Sequenom MassArray system (Sequenom, San Diego, CA) was used to detect three SNPs genotypes in the STAT1 gene: rs10208033, rs12693591, and rs1467199. There is a statistically significant difference in STAT1 rs1467199 allele frequencies with comparison of each of the four clinical subgroups of ITP patients to the normal controls (p = 0.0432). Also, newly diagnosed ITP patients and chronic ITP patients demonstrate significant different genotypes (χ(2 )= 8.511, p = 0.0142) and allelic frequency (p = 0.0055). Although a positive STAT1 rs1467199 genotype subgroups to the STAT1 mRNA expression level cannot be established, there is a weak correlation between STAT1 mRNA level and the activity ratio of Type 1 T helper lymphocyte and Type 2 T helper lymphocyte (Th1/Th2 ratio) (p = 0.0544); correlation with IFN-γ alone did not reach statistical significance (p = 0.1715). The findings in our study suggest that STAT1 rs1467199 SNP plays a potential role in the IFN-γ dependent development of autoimmunity in children with ITP. The important clinical implication of STAT1 SNPs testing as a predictor of pediatric chronic ITP will be validated in future molecular and protein functional analysis.

Foxp3 methylation status in children with primary immune thrombocytopenia

AIM

To investigate the status of DNA methylation in the Foxp3 promoter in pediatric ITP patients and assess the role of DNA methylation of Treg cells in the pathogenesis of ITP.

METHODS

Quantitative DNA methylation levels of Foxp3 promoter in pediatric ITP patients were detected by MassARRAY EpiTYPER. Methylation levels of Foxp3 promoter were analyzed in ITP patients and normal controls.

RESULTS

Significantly higher expression of CpG-2, CpG-3 and CpG-11.12 was observed in ITP patients compared to the controls. A subgroup analysis revealed that persistent and chronic ITP patients exhibited significantly higher CpG-6 expression than in the subgroup of newly diagnosed ITP patients. All patients who represented newly diagnosed ITP at admission were reclassified at later follow-up. In this follow-up subgroup analysis, there were significantly higher levels of CpG-6 in the persistent ITP group than that in the newly diagnosed ITP group.

CONCLUSIONS

Our results indicate that defective Treg cell activity identified in ITP might be partially mediated through hypermethylation of CpG sites in the promoter region of Foxp3.

Cytokine profile of patients with chronic immune thrombocytopenia affects platelet count recovery after Helicobacter pylori eradication

Helicobacter pylori eradication induces platelet recovery in a subgroup of patients with chronic immune thrombocytopenia (cITP), but the mechanisms involved are still not understood. We aimed to evaluate the effect of H. pylori eradication on platelet response and to identify the associated serum cytokine profile in 95 patients with cITP. Serum cytokine concentrations were determined by enzyme-linked immunosorbent assay prior to and 6 months after H. pylori eradication. Remission of cITP was observed in 17 (28·8%) of 59 patients in whom the bacterium was eradicated. Six months after treatment, a significant reduction in the concentrations of T-helper (Th) 1 and Th17 cells and an increase in T regulatory (Treg) and Th2-cell commitment cytokines were observed in patients who recovered, but not in those whose platelet count did not recover. Patients who had a platelet response to eradication of the bacteria had higher pre-treatment serum levels of γ-interferon (IFNG, IFN-γ), transforming growth factor-β (TGFB1, TGF-β) and interleukin 17 (IL17A, IL-17) than patients who did not respond, but only higher pre-treatment TGFB1 levels was independently associated with platelet response. In conclusion, amelioration of cITP after eradication of H. pylori was linked to a more efficient suppression of Th1 and Th17 response and a more pronounced Treg cell response.

Alterations in immune cell subsets and their cytokine secretion profile in childhood idiopathic thrombocytopenic purpura (ITP)

Immune thrombocytopenic purpura (ITP) is acquired autoimmune disease in children characterized by the breakdown of immune tolerance. This work is designed to explore the contribution of different lymphocyte subsets in acute and chronic ITP children. Imbalance in the T helper type 1 (Th1)/Th2 cytokine secretion profile was investigated. The frequency of T (CD3(+), CD4(+), CD8(+)) and B (CD19(+)) lymphocytes, natural killer (NK) (CD16(+) 56(+)) and regulatory T (T(reg)) [CD4(+) CD25(+high) forkhead box protein 3 (FoxP3)(+) ] cells was investigated by flow cytometry in 35 ITP children (15 acute and 20 chronic) and 10 healthy controls. Plasma levels of Th1 cytokines [interferon (IFN-γ) and tumour necrosis factor (TNF-α)] and Th2 [interleukin (IL)-4, IL-6 and IL-10)] cytokines were measured using enzyme-linked immunosorbent assay (ELISA). The percentage of Treg (P < 0·001) and natural killer (NK) (P < 0·001) cells were significantly decreased in ITP patients compared to healthy controls. A negative correlation was reported between the percentage of T(reg) cells and development of acute (r = -0·737; P < 0·01) and chronic (r = -0·515; P < 0·01) disease. All evaluated cytokines (IFN-γ, TNF-α, IL-4, IL-6 and IL-10) were elevated significantly in ITP patients (P < 0·001, P < 0·05, P < 0·05, P < 0·05 and P < 0·001, respectively) compared to controls. In conclusion, our data shed some light on the fundamental role of immune cells and their related cytokines in ITP patients. The loss of tolerance in ITP may contribute to the dysfunction of T(regs). Understanding the role of T cell subsets will permit a better control of autoimmunity through manipulation of their cytokine network.

Absence of association of interleukin-18 gene polymorphisms with primary immune thrombocytopenia in a Chinese Han population

Interleukin-18 (IL-18) is an inflammatory cytokine that plays an important role in autoimmune disease by inducing interferon-γ secretion. Considering the abnormal serum concentration of IL-18 in primary immune thrombocytopenia (ITP) patients and the regulated effect of IL-18 gene polymorphisms on its production, the aim of this study was to investigate a possible association between the IL-18 promoter polymorphisms (-137 G/C and -607 C/A sites) and genetic susceptibility to ITP in a Chinese Han population. A total of 181 ITP patients and 163 healthy controls were included in this study; IL-18 gene promoter polymorphisms were analyzed by a polymerase chain reaction with sequence-specific primers. No significant differences in genotype (-607: χ(2)=0.307, p=0.858; -137: χ(2)=0.378, p=0.828) and allele frequencies (-607: χ(2)=0.004, p=0.949; -137: χ(2)=0.307, p=0.858) were found between total ITP patients and normal controls. We further analyzed the association of IL-18 polymorphisms with clinical parameters of ITP patients, including first onset age and clinical therapy response to glucocorticoids, and no difference was revealed. In conclusion, IL-18 promoter polymorphisms may not be associated with genetic susceptibility to ITP in a Chinese Han population.

In vitro evaluation of clot quality and stability in a model of severe thrombocytopenia: effect of fibrinogen, factor XIII and thrombin-activatable fibrinolysis inhibitor

BACKGROUND

The treatment options in severe thrombocytopenia (platelet count ≤20×10(9)/L) are limited. The aim of this study was to investigate ways of improving blood clotting and stability in reconstituted thrombocytopenia.

MATERIALS AND METHODS

Thrombocytopenia (platelets [16±4]×10(9)/L) was created by differential centrifugation of normal blood followed by reconstitution of whole blood which was subjected to clotting in a rotation thromboelastometer by CaCl2 and tissue factor, and to fibrinolysis by tissue plasminogen activator (tPA). In separate experiments, blood was diluted by 40% with TRIS/saline solution. Blood was treated with fibrinogen (fib), factor XIII (FXIII), and thrombin-activatable fibrinolysis inhibitor (TAFI).

RESULTS

The maximum clot firmness of thrombocytopenic blood was approximately 2-fold less than that of intact blood. Supplementation of blood with fib and FXIII improved clot formation. In the presence of tPA, among fib, FXIII and TAFI, only fib stimulated clot propagation whereas each of these agents increased clot strength. There was a synergistic effect when fib was added together with FXIII or TAFI. Fibrinolysis was inhibited by TAFI and to a greater extent by TAFI + FXIII. Fourty percent dilution of blood reduced clot strength and increased susceptibility to tPA. Clot strength was increased by the treatments in the following order: fib/FXIII/TAFI > fib/TAFI > fib > TAFI > FXIII. In the presence of tPA, TAFI and FXIII lysed the clots significantly more slowly. This effect was stronger when blood was treated with the combination of fib/FXIII/TAFI. Doubling the fib concentration, alone or together with other agents, did not improve clot strength or stability.

DISCUSSION

Augmentation of clot formation and anti-fibrinolysis by combining fib, FXIII and TAFI may be beneficial for the treatment of patients with severe thrombocytopenia especially when complicated by haemodilution following introduction of fluids to compensate for massive blood loss.

The polymorphisms of T cell-specific TBX21 gene may contribute to the susceptibility of chronic immune thrombocytopenia in Chinese population

Chronic primary immune thrombocytopenia (ITP) is an acquired autoimmune hemorrhagic disease characterized by both reduced platelet counts and suppression of megakaryocyte and platelet development. T cell-specific T-box transcription factor gene (TBX21) plays a critical role in the development and maintenance of T helper 1 (Th1) cells. Recently, several studies have confirmed that the T-1554C and T-1993C polymorphisms of this gene can influence its expression level and are associated with autoimmune diseases. Therefore, we speculated that TBX21 polymorphisms might be associated with the susceptibility of chronic ITP in Chinese population. We investigated the distributions of TBX21 (T-1514C and T-1993C) polymorphisms in 275 patients with chronic ITP and 261 healthy controls by polymerase chain reaction-restriction fragment length polymorphism. We observed significant overrepresentation of T allele and T/T genotype at T-1993C (but not T-1514C) in patients compared with controls. Stratified analysis by gender and age of disease onset revealed comparable observations in both female and childhood ITP cohorts. In conclusion, the T-1993C polymorphisms of TBX21 gene may be associated with the susceptibility of chronic primary ITP in Chinese population.

Elevated NKT cell levels in adults with severe chronic immune thrombocytopenia

The aim of this study was to investigate the frequency of circulating natural killer T (NKT) cells and regulatory T cells (Tregs), as well as serum cytokine profiles, in adult chronic primary immune thrombocytopenia (ITP). The frequency of circulating T cell receptor (TCR) Vα24⁺Vβ11⁺CD3⁺ NKT cells and CD4⁺CD25⁺CD127^−/low Tregs was measured using multi-color flow cytometry. The serum concentrations of 11 cytokines were determined with a cytometric bead assay. The frequency of circulating NKT cells in patients with ITP was 0.13±0.03%, whereas the frequency in healthy controls was 0.07±0.01% of CD3⁺ (P>0.05). However, the frequency of NKT cells in patients with ITP with platelet counts ≤20×10⁹/l (0.22±0.05%) was significantly higher than that in patients with platelet counts >20×10⁹/l (0.05±0.01%; P<0.05) and that in healthy controls (0.07±0.01%; P<0.05). The frequency of peripheral Tregs was comparable between patients with ITP (3.97±0.44% of CD4⁺) and healthy controls (3.69±0.31%; P>0.05). No significant differences were observed in the serum concentrations of 11 cytokines between patients with ITP and healthy controls, despite the fact that the serum levels of interleukin (IL)-12p70, IL-8, IL-4, interferon (IFN)-γ and tumor necrosis factor (TNF)-α in patients with ITP were higher than those in the healthy controls. The platelet count was negatively correlated with the frequency of circulating NKT cells in chronic ITP. These results indicate that NKT cells may be involved in ITP with severe thrombocytopenia, and NKT and Tregs may be important in cytokine deregulation in chronic ITP.

Lack of Impact of Cytotoxic T-Lymphocyte Antigen 4 Gene Exon 1 Polymorphism on Susceptibility to or Clinical Course of Egyptian Childhood Immune Thrombocytopenic Purpura

Dysfunctional T-lymphocyte immunity plays an important role in the pathophysiology of immune thrombocytopenic purpura (ITP). Cytotoxic T-lymphocyte antigen 4 ( CTLA-4)—a surface marker expressed on T regulatory cells and activated T lymphocytes—is a negative modulator of T-cell responses. Polymorphisms of the CTLA-4 may alter the level of antigen expression and hence may influence immune regulation. The study aimed to evaluate the possible contribution of CTLA-4 exon 1 49 A>G polymorphism to the pathogenesis of ITP and its relation to age of disease onset, clinical course, and response to therapy. Genotyping of CTLA-4 exon 1 49 A>G was performed in 100 pediatric patients with ITP and 259 healthy individuals by polymerase chain reaction–restricted fragment length polymorphism. No significant differences existed in genotype or allele distributions between patients and controls for the studied polymorphism. Comparable genotypes and allele frequencies were obtained between the 2 groups after their stratification by age of disease onset, clinical course, or response to therapy. In conclusion, CTLA-4 exon 1 49 A>G polymorphism is not associated with susceptibility to ITP in the Egyptian population; neither it affects the clinical picture of the disease.

DNMT3B promoter polymorphism and risk of immune thrombocytopenic purpura in pediatric Egyptians

Idiopathic (immune) thrombocytopenic purpura (ITP) is a heterogeneous clinical disorder characterized by immune-mediated platelet destruction. Epigenetic changes in gene expression, including DNA methylation and histone modifications, might contribute to autoimmunity. Polymorphisms of the DNA methyltransferase 3B (DNMT3B) gene may influence DNMT3B activity on DNA methylation and increase the susceptibility to several diseases. The current study investigated the association between a single nucleotide polymorphism (SNP) in the promoter of DNMT3B gene and the risk for ITP in pediatric Egyptians. DNMT3B SNP was genotyped by PCR-restriction fragment length polymorphism in 71 pediatric ITP patients and 82 healthy controls matched for age and sex. The C/C wild genotype was not detected in ITP patients or in the controls. The frequencies of the T/T and C/T genotypes were 93.9 and 6.1% in the controls and 91.5 and 6.1% in ITP patients, respectively. There was no significant difference in either genotypes or allelic distribution between ITP patients and the controls. In conclusion, this polymorphism was almost equally distributed between ITP patients and the controls. These results demonstrated that this SNP may not be used as a stratification marker to predict the susceptibility to childhood ITP in Egypt.

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.

Fcγ receptor gene polymorphisms in childhood immune thrombocytopenic purpura

Immune thrombocytopenic purpura (ITP) is a common hematological disorder in the childhood, and it is one of the most common forms of autoimmune disease in pediatric patients. The ITP basis is a primary dysfunction of the immune system. This study aimed to analyze the genetic polymorphisms of the Fcγ receptors IIA and IIIA. The genetic polymorphisms of the Fc receptors γIIA (131H/R) and γRIIIA (158V/F) were analyzed by polymerase chain reaction-restriction fragment length polymorphism technique. Odds ratio and 95% confidence interval were calculated by χ(2) test. Homozygous polymorphic genotype for the FcγRIIIA was significantly more frequent among patients compared with controls (odds ratio = 0.27; 95% confidence interval, 0.09-0.80; P = 0.03). There was no statistical difference between the ITP group and the controls in the analysis of combinations of alleles of the high-affinity Fc receptor, but the ITP individuals with this combination had a lower duration of disease (P = 0.01). Genetic polymorphisms in immune system genes can be important for ITP pathogenesis and disease outcome.

Transplantation of adipose-derived mesenchymal stem cells into a murine model of passive chronic immune thrombocytopenia

BACKGROUND

Immune thrombocytopenia (ITP) is a bleeding disorder characterized by antibody-opsonized platelets (PLTs) being prematurely destroyed by macrophages in the reticuloendothelial system. T helper (Th) cells and different Th cytokines play an important role in the pathophysiology of ITP. As immunomodulators, adipose-derived mesenchymal stem cells (ADSCs) regulate Th cells and show therapeutic effects in autoimmune diseases. However, it is not clear how ADSCs affect ITP. In this study, we explored the specific effects of ADSCs on ITP in mice.

STUDY DESIGN AND METHODS

BALB/c mice were randomly divided into three groups: normal controls, ITP controls, and ITP with ADSC transplantation. PLT levels were monitored by an automatic blood cell counter, and the cytokines interferon-γ (IFN-γ); interleukin (IL)-2, -4, -10, and -17; and transforming growth factor-β1 (TGF-β1) were analyzed by enzyme-linked immunosorbent assays.

RESULTS

Compared to the untreated ITP mice, the PLT level of the ITP mice significantly increased after ADSC treatment. In the ADSC group, IFN-γ, IL-2, and IL-17 significantly decreased, while IL-4, IL-10, and TGF-β1 increased.

CONCLUSION

These findings constitute the first experimental evidence that ADSCs are efficacious in improving PLT levels and reducing the related Th cytokines mediating proinflammatory response in ITP mice, which may provide a scientific basis for using ADSCs as a new therapy for ITP.

The levels of IL-17A and of the cytokines involved in Th17 cell commitment are increased in patients with chronic immune thrombocytopenia

Th17 cells have been associated with immune-mediated diseases in humans but it has still not been determined whether they play a role in immune thrombocytopenia. We evaluated representative cytokines of the Th17, Th1, Th2 and Treg cell commitment in the serum of patients with chronic immune thrombocytopenia, as well as the cell source of IL-17A. Higher levels of IL-17A and Th17-related cytokines, and an increased percentage of IL-17A producing CD4+ and neutrophils were observed in patients. The levels of cytokines involved in Th1 cell commitment IFN-γ, IL-2, IL12-p70 and the percentages of Th1 cells were also increased, but IL-4 was not detected. Although the concentrations of IL-10 were higher, the levels of TGF-β were similar in both groups. In conclusion, our results point to a putative role for Th-17 cells/IL-17A cytokine in the pathogenesis of chronic immune thrombocytopenia.

Circulating plasmacytoid dendritic cells in patients with primary and Helicobacter pylori-associated immune thrombocytopenia

OBJECTIVES

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by the production of autoreactive antibodies against platelet antigens. Although dysfunction of multiple aspects of cellular immunity is considered to be important in the pathogenesis of ITP, it has not been clarified which cell types play a principal role.

METHODS

We enrolled 46 untreated patients with chronic ITP and 47 healthy adult volunteers, and investigated by flow cytometry the percentage and absolute number of cells in their peripheral blood that participate in the regulation of cellular immunity. These included plasmacytoid dendritic cells (pDCs), myeloid dendritic cells (mDCs), natural killer (NK) cells, natural killer T (NKT) cells, regulatory T (Treg) cells, and Th17 cells.

RESULTS

We found a significant reduction in the absolute number of pDCs, but not of mDCs, in patients with ITP when compared with healthy controls (P < 0.001). Reduced numbers of circulating pDCs were observed in both Helicobacter pylori (H. pylori)-positive and Helicobacter pylori (H. pylori)-negative patients with ITP. In contrast, there were no significant differences in the numbers of circulating Treg cells, Th17 cells, NK cells, or NKT cells. Interestingly, we observed increases in the number of pDCs after H. pylori eradication by antibiotics in responders but not in non-responders, while pDCs and mDCs decreased markedly after prednisolone therapy in both responders and non-responders. In patients without treatment, low pDC numbers persisted during the observational period.

CONCLUSIONS

We demonstrated that the number of circulating pDCs is low in patients with primary and H. pylori-associated ITP and that it changes depending on treatment modality. Further investigation is warranted with regard to the role of pDCs in the immunopathogenesis of ITP.