Mendelian randomization reveals association of gut microbiota with Henoch-Schönlein purpura and immune thrombocytopenia.

Gut microbiota have been linked to immune thrombocytopenia (ITP) and Henoch-Schönlein purpura (HSP) in recent studies, but a cause-and-effect relationship is unclear. We used Mendelian randomization (MR) to assess causal relationships between gut microbiota and HSP/ITP using summary statistics from the GWAS dataset of the international MiBioGen and FinnGen consortium. The IVW method was used as the main evaluation indicator. MR analysis of 196 intestinal flora and HSP/ITP/sTP phenotypes showed that 12 flora were potentially causally associated with ITP, 6 with HSP, and 9 with sTP. The genes predicted that genus Coprococcus3 (p = 0.0264, OR = 2.05, 95% CI 1.09-3.88)and genus Gordonibacter (p = 0.0073, OR = 1.38; 95% CI 1.09-1.75) were linked to a higher likelihood of developing ITP. Additionally, family Actinomycetaceae (p = 0.02, OR = 0.51, 95% CI 0.28-0.90) and order Actinomycetales (p = 0.0199, OR = 0.50, 95% CI 0.28-0.90) linked to reduced HSP risk. Genus Ruminococcaceae UCG013 (p = 0.0426, OR = 0.44, 95% CI 0.20-0.97) negatively correlated with sTP risk. Our MR analyses offer evidence of a possible cause-and-effect connection between certain gut microbiota species and the likelihood of HSP/ITP.

Comparison of platelet transfusion effectiveness between Helicobacter pylori-positive and -negative immune thrombocytopenia.

Immune thrombocytopenia (ITP) is characterized by early platelet destruction and impaired platelet production. Helicobacter pylori (H. pylori) infection seems to contribute to the pathogenesis in certain ITP patients in Japan. We compared the effectiveness of platelet transfusion in severe ITP in the presence or absence of H. pylori. The median corrected count increment (CCI) at 24 h after platelet transfusion (CCI-24) of the H. pylori-positive ITP patients was higher than that of the H. pylori-negative ITP patients (6463 vs. 754, p < 0.001), and the CCI-1 was also in the same direction but not significant (23 351 vs. 11 578). Multiple regression analyses showed that H. pylori infection was independently associated with CCI-24. Our study suggests that platelet transfusion may be more effective in H. pylori-positive ITP patients.

Gut microbiome alterations and its link to corticosteroid resistance in immune thrombocytopenia.

Quantitative metagenomic studies have linked the gut microbiota to autoimmune disorders. Here, we performed deep shotgun metagenomic sequencing of fecal samples from 99 immune thrombocytopenia (ITP) patients and 52 healthy controls. Dysbiosis in the gut microbiome of ITP was detected phylogenetically and functionally, and classifier based on species markers distinguished individuals with ITP from healthy controls. In particular, the abundance of Ruminococcus gnavus, Bifidobacterium longum and Akkermansia muciniphila was markedly increased in treatment-naïve ITP patients, and the alterations of microbial species were correlated with clinical indices. Functionally, the secondary bile acid biosynthesis and flagellar assembly were depleted in the gut microbiota of ITP, which may contribute to the onset of ITP by affecting the immune system. Furthermore, we found that corticosteroid treatment affected the gut microbiome of ITP. Compared with corticosteroid-sensitive ITP patients, we identified that the corticosteroid-resistant ITP patients displayed a distinct gut microbiome, which was different from that of the treatment-naïve ITP patients. Together, we provided support for the critical role of gut microbiota in the development of ITP and established a foundation for further research characterizing gut microbiota in relation to corticosteroid resistance of ITP.

Helicobacter pylori and hematological disorders.

Helicobacter pylori (H. pylori) is one of the most common worldwide infections, which can affect both adults and children. The prevalence of this bacterium is variable in different countries, depending on various hygienic and socioeconomic conditions and living customs. The major damaged tissues of the infection are in the upper gastrointestinal tract, causing gastritis, gastric and duodenal ulcer and gastrointestinal malignancy. Nevertheless, other disorders are associated with this pathogen, including several hematological diseases, such as iron deficiency anemia, immune thrombocytopenia and vitamin B12 deficiency. A huge of data in literature support these associations, enough to recognize them in the last Maastricht V/Florence Consensus Report by European Study Group. The pathogenic mechanisms underlying the linkage between H. pylori and these hematological disorders are not clearly identified, but certainly the good hematological response reaches after eradication therapy confirm a central role of the bacterium in this scenario. Instead, the pathogenic mechanisms of H. pylori infection, which lead to the occurrence of mucosa-associated lymphoid tissue (MALT) lymphoma are clearer and more consolidated; so much that nowadays eradication therapy alone represents the only treatment in this disorder, when localized and with a concomitant H. pylori infection. This review focuses on the hematologic diseases related to H. pylori, particularly on iron deficiency anemia, vitamin B12 deficiency, immune thrombocytopenia and gastric MALT lymphoma.

Helicobacter pylori and extragastric diseases.

Many studies have been performed in the last year concerning the potential role of Helicobacter pylori in different extragastric diseases, reinforcing the idea that specific microorganisms may cause diseases even far from the primary site of infection. While the role of H. pylori on idiopathic thrombocytopenic purpura, sideropenic anemia, and vitamin B12 deficiency has been well established, there is a growing interest in other conditions, such as cardiovascular, neurologic, dermatologic, obstetric, immunologic, and metabolic diseases. Concerning neurologic diseases, there is a great interest in cognitive impairment and neurodegeneration. The aim of this review was to summarize the results of the most relevant studies published over the last year on this fascinating topic.

Does Helicobacter pylori eradication play a role in immune thrombocytopenia? / ¿Tiene algún rol la erradicación de Helicobacter pylori en la trombocitopenia inmune?

Helicobacter pylori infection has been implicated as trigger or disease modifier in immune thrombocytopenia (ITP). So, eradication treatment for this agent could have clinical benefits. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified four systematic reviews comprising 40 studies addressing the question of this article overall, including one randomized controlled trial. We combined the evidence using meta-analysis and generated a summary of findings following the GRADE approach. We concluded Helicobacter eradication might decrease risk of bleeding in patients with immune thrombocytopenia but the certainty of the evidence is low.

Se ha planteado que el Helicobacter pylori tendría un rol etiopatogénico en la trombocitopenia inmune (PTI), y que la erradicación de este podría tener beneficios clínicos. Utilizando la base de datos Epistemonikos, la cual es mantenida mediante búsquedas en 30 bases de datos, identificamos cuatro revisiones sistemáticas que en conjunto incluyen 40 estudios, entre ellos un estudio controlado aleatorizado, que responden la pregunta de interés. Realizamos un metanálisis y tablas de resumen de los resultados utilizando el método GRADE. Concluimos que la erradicación de Helicobacter podría disminuir el riesgo de sangrado en pacientes con trombocitopenia inmune, pero la certeza de la evidencia es baja.

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.

Is Helicobacter pylori infection a risk factor for idiopathic thrombocytopenic purpura in children?

BACKGROUND: Idiopathic thrombocytopenic purpura (ITP) is an autoimmune bleeding disorder, which occurs as a result of autoantibodies attachment to the platelets surface and subsequent destruction. Several organisms can mimic features of human antigens (Ags) and induce autoantibody production. One of these organisms is Helicobacter pylori (HP). We assessed the prevalence and relationship of HP infection with ITP in a population of children. MATERIALS AND METHODS: One hundred and six children younger than 18 years old were enrolled in this case-control study in which 42 children with ITP were in the case group and 64 healthy children were in the control group. Stool exam for detection of HP-Ag were performed and the variables were compared between the two groups. RESULTS: Mean ± standard deviation age of case and control group was 6.4 ± 3.4 and 8.6 ± 4.4 years old, respectively. HP stool Ag differ significantly between the case and the control groups (P < 0.05). CONCLUSION: Our results support the role of HP in ITP of children, and urea breath test or Ag detection of HP in stool of these patients is recommended.

Helicobacter pylori Eradication in Patients with Immune Thrombocytopenic Purpura: A Review and the Role of Biogeography.

Idiopathic thrombocytopenic purpura (ITP) is typically a diagnosis of exclusion, assigned by clinicians after ruling out other identifiable etiologies. Since a report by Gasbarrini et al. in 1998, an accumulating body of evidence has proposed a pathophysiological link between ITP and chronic Helicobacter pylori (H. pylori) infection. Clinical reports have described a spontaneous resolution of ITP symptoms in about 50% of chronic ITP patients following empirical treatment of H. pylori infection, but response appears to be geography dependent. Studies have also documented that ITP patients in East Asian countries are more likely to express positive antibody titers against H. pylori-specific cytotoxic-associated gene A (CagA), a virulence factor that is associated with an increased risk for gastric diseases including carcinoma. While a definitive mechanism by which H. pylori may induce thrombocytopenia remains elusive, proposed pathways include molecular mimicry of CagA by host autoantibodies against platelet surface glycoproteins, as well as perturbations in the phagocytic activity of monocytes. Traditional treatments of ITP have been largely empirical, involving the use of immunosuppressive agents and immunoglobulin therapy. However, based on the findings of clinical reports emerging over the past 20 years, health organizations around the world increasingly suggest the detection and eradication of H. pylori as a treatment for ITP. Elucidating the exact molecular mechanisms of platelet activation in H. pylori-positive ITP patients, while considering biogeographical differences in response rates, could offer insight into how best to use clinical H. pylori eradication to treat ITP, but will require well-designed studies to confirm the suggested causative relationship between bacterial infection and an autoimmune disease state.

Significance of lymphocyte counts at diagnosis in the management of ITP: the relationship between lymphocyte counts and treatment success in H. pylori-infected patients.

Immune thrombocytopenic purpura (ITP) is an acquired disorder characterized by thrombocytopenia, increased platelet destruction, and the inhibition of platelet production by specific autoantibodies. Previous studies have reported improvements in ITP following the eradication of Helicobacter pylori (H. pylori) infection. We, herein, investigated the relationship between initial therapy for ITP and lymphocyte counts at diagnosis. We retrospectively examined 52 adult patients with ITP between March 1998 and March 2013. Standard H. pylori eradication therapy was performed in 31 patients, and lymphocyte counts were compared before and after this therapy. At the diagnosis of ITP, lymphocyte counts in H. pylori-infected patients were significantly higher than those in H. pylori-negative patients (1.92 ± 0.68 × 10(9)/L vs. 1.42 ± 0.67 × 10(9)/L; p = 0.010). H. pylori eradication was successful in 6/11 patients (54.5 %) and the platelet count increased in 4/11 H. pylori-positive patients (36.4 %) who received eradication therapy. On the other hand, eradication therapy was also administered to 15 patients without H. pylori infection, and responses were obtained in some H. pylori-negative patients receiving eradication therapy (9/15). Furthermore, lymphocyte counts were significantly higher in patients who achieved a complete response receiving H. pylori eradication therapy than in patients who did not achieve a complete response (2.4 ± 0.59 × 10(9)/L vs. 1.37 ± 0.60 × 10(9)/L, p = 0.0023). The response of ITP patients to the initial treatment may be predicted by measuring the lymphocyte count at diagnosis. Further studies that analyze lymphocyte subsets and the cytokine network are needed to elucidate the underlying mechanisms.

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-ß (TGFB1, TGF-ß) 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.

Helicobacter pylori infection & immune thrombocytopenic purpura in children and adolescents: A randomized controlled trial.

Helicobacter pylori and immune thrombocytopenic purpura (ITP) association is not well established in chronic ITP (cITP) in children, although the cure of thrombocytopenia in approximately half of H. pylori eradicated adult patients has been described. The aim of this study was to investigate the effect of H. pylori eradication on platelet (PLT) recovery in cITP children and adolescents through a randomized, controlled trial. A total of 85 children (mean age 11.4 years) with cITP were prospectively enrolled. Diagnosis of H. pylori was established by two locally validated tests, (13)C-urea breath test and monoclonal stool antigen test. Twenty-two infected patients were identified, and randomly allocated into two groups: H. pylori treatment group (n = 11) and the non-intervention control group (n = 11). The control group was offered treatment if the thrombocytopenia persisted after the follow-up. At baseline, there were no differences regarding age, sex, duration of disease, and PLT count between groups. Sixty three of 85 patients were uninfected. PLT response was classified as complete response: PLT > 150 × 10(9 )l(-1); partial response: PLT 50-150 × 10(9 )l(-1), or an increase of 20-30 × 10(9 )l(-1); no response: PLT < 50 × 10(9 )l(-1) or an increase of <20 × 10(9 )l(-1) after at least 6 months of follow-up. Complete response was observed in 60.0% (6/10, one excluded) H. pylori eradicated patients vs. 18.2% (2/11) in non-eradicated patients (p = 0.08; OR = 6.75) after 6-9 months of follow-up. Among uninfected patients, only 13.8% (8/58) presented complete response. Two non-treated controls were treated after 6-12 months of follow-up, and PLT response was observed in 61.5% (8/13) of H. pylori eradicated patients, and in 19.0% (11/58) of uninfected patients (p = 0.004). Cytotoxin associated gene A and vacuolating cytotoxin gene A IgG antibodies were present in almost all infected patients. Therefore, the study suggests that H. pylori eradication plays a role in the management of H. pylori infected cITP children and adolescents.

Helicobacter pylori infection in Mongolian gerbils does not initiate hematological diseases.

AIM: To investigate whether Helicobacter pylori (H. pylori) infection contributes to idiopathic thrombocytopenic purpura (ITP) or iron-deficiency anemia (IDA) onset in gerbils. METHODS: A total of 135 Mongolian gerbils were randomly divided into two groups: an H. pylori infection group and a control group. Both groups were fed the same diet and the same amount of food. Each group was then divided into three subgroups, which were sacrificed at 6, 12, or 18 mo for analysis. At each time point, arterial blood was collected from the abdominal aorta and a complete blood cell count was analyzed in the clinical laboratory in the First Affiliated Hospital of Nanchang University. RESULTS: There were no significant differences in platelet counts (938.00 ± 270.27/L vs 962.95 ± 162.56 × 10(9)/L), red blood cell counts (8.11 ± 1.25/L vs 8.44 ± 1.48 × 10(12)/L), or hemoglobin levels (136.9 ± 8.76 g/L vs 123.21 ± 18.42 g/L) between the control and the H. pylori groups, respectively, at 18 mo. With the exception of the mean corpuscular volume (MCV), all other indicators, including white blood cell counts, hematocrit, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red blood cell distribution width, mean platelet volume, platelet distribution width, lymphocyte count, and lymphocyte count percentage, showed no significant differences between the control and H. pylori infection groups at each time point. The MCV in the H. pylori infection group (52.32 f/L ± 2.86 f/L) was significantly lower than the control group (55.63 ± 1.89 f/L) at 18 mo (P = 0.005), though no significant differences were observed at 6 (54.40 ± 2.44 f/L vs 53.30 ± 1.86 f/L) or 12 mo (53.73 ± 2.31 f/L vs 54.80 ± 3.34 f/L). CONCLUSION: A single H. pylori infection is insufficient to cause onset of ITP or IDA and other factors may be required for disease onset.

From prednisone to pylori: a case of Helicobacter pylori-induced chronic immune thrombocytopenia.

A 54-year-old woman was seen by her primary care internist for a general health maintenance visit. Her major chronic illness was immune thrombocytopenic purpura (ITP) for which she had been treated with prednisone therapy for the past 15 years. Recent review of possible aetiologies of her chronic thrombocytopenia revealed infection with Helicobacter pylori. Successful eradication resulted in complete resolution of her thrombocytopenia within 2 months. She was weaned from steroid therapy and at 1-year follow-up, her platelet counts remained in the normal range. This case report summarises what is known about the association of H. pylori infection and ITP.

Immune thrombocytopenic purpura induced by intestinal tuberculosis in a liver transplant recipient.

A variety of clinical manifestations are associated directly or indirectly with tuberculosis. Among them, haematological abnormalities can be found in both the pulmonary and extrapulmonary forms of the disease. We report a case of immune thrombocytopenic purpura (ITP) associated with intestinal tuberculosis in a liver transplant recipient. The initial management of thrombocytopenia, with steroids and intravenous immunoglobulin, was not successful, and the lack of tuberculosis symptoms hampered a proper diagnostic evaluation. After the diagnosis of intestinal tuberculosis and the initiation of specific treatment, a progressive increase in the platelet count was observed. The mechanism of ITP associated with tuberculosis has not yet been well elucidated, but this condition should be considered in cases of ITP that are unresponsive to steroids and intravenous immunoglobulin, especially in immunocompromised patients and those from endemic areas.

Helicobacter pylori infection and extragastric disorders in children: a critical update.

Helicobacter pylori (H. pylori) is a highly prevalent, serious and chronic infection that has been associated causally with a diverse spectrum of extragastric disorders including iron deficiency anemia, chronic idiopathic thrombocytopenic purpura, growth retardation, and diabetes mellitus. The inverse relation of H. pylori prevalence and the increase in allergies, as reported from epidemiological studies, has stimulated research for elucidating potential underlying pathophysiological mechanisms. Although H. pylori is most frequently acquired during childhood in both developed and developing countries, clinicians are less familiar with the pediatric literature in the field. A better understanding of the H. pylori disease spectrum in childhood should lead to clearer recommendations about testing for and treating H. pylori infection in children who are more likely to develop clinical sequelae. A further clinical challenge is whether the progressive decrease of H. pylori in the last decades, abetted by modern clinical practices, may have other health consequences.