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 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 × 10⁹/L), red blood cell counts (8.11 ± 1.25/L vs 8.44 ± 1.48 × 10¹²/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.

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.

Helicobacter pylori-associated immune thrombocytopenia: Clinical features and pathogenic mechanisms

Immune thrombocytopenia (ITP) is an autoimmune disease mediated by anti-platelet autoantibodies. There is growing evidence that the eradication of Helicobacter pylori (H. pylori) effectively increases platelet count in a considerable proportion of ITP patients infected with this bacterium. In the majority of ITP patients responding to H. pylori eradication therapy, the anti-platelet autoantibody response is completely resolved with no relapse for more than 7 years, indicating that the disease is cured. Therefore, adult patients with suspected ITP should be examined for H. pylori infection, and eradication therapy is recommended if the infection is present. Notably, however, the efficacy of H. pylori eradication therapy in ITP patients varies widely among countries, with a higher response rate in Japan compared with the United States and European countries other than Italy. The pathogenesis of H. pylori-associated ITP is still uncertain, although the mechanisms are known to involve multiple factors. H. pylori may modulate the Fcγ-receptor balance of monocytes/macrophages in favor of activating Fcγ receptors, and H. pylori components may mimic the molecular makeup of platelet antigens. Further studies of the pathogenic process of H. pylori-associated ITP may be useful for the development of new therapeutic strategies for ITP.

The role of Helicobacter pylori infection in hematological disorders

Helicobacter pylori (H. pylori) is a Gram-negative spiral bacterium, classified as a carcinogen of class I, according to the World Health Organization (WHO). The infection is a major cause of gastritis, gastric and duodenal ulcer disease and increases the risk of gastric cancer. It has been implicated in the pathogenesis of several gastrointestinal, systemic or hematological diseases. The present review aims in deciphering the role of the bacterium in hematological disorders, increasing the awareness of gastroenterologists, hematologists and internal medicine practitioners, regarding the bacterium-associated hematological diseases. The efficacy of H. pylori eradication in increasing the platelet count in adult patients with primary immune thrombocytopenia (ITP) has been confirmed, linking the infection with the disease. Moreover, as the bacterium causes iron deficiency anemia (IDA) by several mechanisms, recent guidelines indicate H. pylori infection (Hp-I) to be sought in IDA patients if histology is negative and to be eradicated if present. Furthermore, it has been widely recognized that anti-H. pylori treatment causes regression of the low-grade B-cell gastric MALT lymphomas. Despite the well established associations of Hp-I with the aforementioned hematological disorders, we highlight the possible role of the infection to other hematological diseases or conditions such as non-Hodgkin lymphomas of the stomach, monoclonal gammopathy of undetermined significance, megaloblastic anemia and myelodysplastic syndromes. We finally underline the elevated risk of childhood leukemia and of hemorrhage in patients with coagulation disorders, due to the infection.

Human T-lymphotropic virus type I infection and idiopathic thrombocytopnic purpura

Human T-lymphotropic virus type I (HTLV-I) is the causative agent in adult T-cell leukemia and HTLV-I associated myelopathy. Some other diseases such as uveitis, chronic thyroiditis, Sjögren syndrome, arthritis, acute myeloid leukemia and myelodysplastic syndrome may be also associated with HTLV-I. Several case reports have suggested the possible combination of idiopathic thrombocytopenic purpura (ITP) and HTLV-I infection. In these studies and from our current report, we found 17 patients (22.1%) with HTLV-I infection among 77 ITP patients. The prevalence of HTLV-I infection among ITP patients was higher than that of healthy volunteers (5 approximately 10%). The ITP patients with HTLV-I infection were older than the patients without HTLV-I infection, and the ITP patients with HTLV-I infection had poor response to prednisolone therapy. Among 17 ITP patients with HTLV-I infection, 9 patients received prednisolone therapy. Although most patients had transient increase of platelet counts, only two of them had partial responses (PR) at the last observation date. Five patients underwent splenectomy, and four of them had complete responses (CR) and the remaining patient had a (PR). Four patients received eradication of Helicobactor pylori (H. pylori) infection, and all patients had CRs. Therefore, the ITP patients with HTLV-I infection should receive eradication therapy in the case of H. pylori infection as the first step of therapy and the splenectomy should be considered, if there is no response to conventional therapy. Human immunodeficiency virus (HIV) causes thrombocytopenia in 10% of patients with active HIV disease. The etiologies of HIV thrombocytopenia are considered as follows, the escalated destruction of platelets by the immune system, damage to megakaryocytes by HIV infection and the inhibition of thrombopoiesis by some anti-viral drugs. In the case of ITP patients with HTLV-I infection, the main etiology may be the increased destruction of platelets by immune system. The proviral load and the integration pattern of HTLV-I should be examined to clarify the stage of HTLV-I infection. The possibility of infection of the megakaryocytes by HTLV-I should be also examined for etiological approach.

Study of host immunity in patients with Helicobacter pylori-related idiopathic thrombocytopenia

To test the role of T helper cell Th1 immunity we recruited 24 patients with idiopathic thrombocytopenia associated with H. pylori seropositivity. They were divided into 2 groups: 12 with immune-mediated thrombocytopenia (Group 1) and 12 with non-immune mediated thrombocytopenia (Group 2). We also recruited 10 individuals seronegative for H. pylori (Group 3) as controls. Initial platelet count was significantly lower in Group 1 than Group 2. H. pylori was eradicated in 10 of 12 patients in Group 1 and in all patients in Group 2. Transient improvement (< 3 months) in the platelet count occurred in only 2 patients in Group 1 while improvement for > 6 months was observed in all patients in Group 2. There was a statistically significant direct correlation between platelet count and levels of TNF- and IFN-gamma in both study groups, while a non-significant correlation was seen in Group 3. Thus, H. pylori infection should be considered in the differential diagnosis of all cases of thrombocytopenia, and should be eradicated in all H. pylori-positive patients with thrombocytopenia.

[Role of Helicobacter pylori infection in the pathogenesis and clinical outcome of childhood acute idiopathic thrombocytopenic purpura]

OBJECTIVE

To investigate the role of Helicobacter pylori (Hp) and its products cytotoxin-associated protein (Cag A), vacuolating cytotoxin (VacA) in childhood acute idiopathic thrombocytopenic purpura (aITP), to evaluate the effect of Hp on their clinical outcome.

METHODS

Subjects were enrolled according to case-control design, including 184 aITP children and 154 healthy controls. They were inquired for demographic characteristics, the risk factors regarding Hp infection and ITP through a uniformed questionnaire. Patients with Hp infection were diagnosed by combined detection of serum Hp antibodies and stool antigens. CagA and VacA proteins were tested by ELISA method. In addition, clinical data and follow-up data of aITP children were collected. Non-conditional logistic regression and t test were applied for statistical analysis.

RESULTS

(1) The prevalence of Hp infection in aITP children and controls were 41.30% and 35.71%, respectively. No association between Hp infection and children aITP was found with OR of 1.170 (95%CI: 0.7163 - 1.673) after adjusting for confounding variables. (2) No statistical differences regarding initial platelet counts, megakaryocytes counts and the constituent ratio were found between the aITP children with and without Hp infection (P > 0.05). (3) No differences regarding initial platelet counts were found between aITP children with and without the expression of CagA (P > 0.05). The follow-up data showed that 32.88% of aITP children with Hp infection, as well as 29.70% of aITP children without Hp infection developed into cITP. No association between Hp infection and development to cITP was found with adjusted OR 1.171 (95%CI: 0.555 - 2.11 2).

CONCLUSIONS

The results didn't suggest that Hp is unlikely to play a role in the onset of childhood aITP, and in the development of aITP to cITP.

[Helicobacter pylori-induced thrombocytopenia]

Immune thrombocytopenic purpura (ITP) is a multicausal disease. In the majority of cases, autoimmune antibodies against thrombocytes and other autoimmune processes play a role. However, in about 20% of cases an underlying cause can be identified. Recently, Helicobacter pylori infection was recognized as one of these underlying causes. We present two patients with ITP in whom a significant increase of thrombocytes occurred after eradication of H. pylori. In the first patient, a 75-year-old man, experimental therapy was withheld. The second patient, a 47-year-old man, never received immunosuppressive medication. H. pylori screening and eradication should be standard practice in the work up of a patient with thrombocytopenia. Despite the lack of clear pathophysiological understanding, in a minority of ITP cases there is evidence of a correlation between H. pylori infection and ITP. Tests and treatment are non-invasive, cheap and without major side-effects. In the event of a platelet response, expensive immunosuppressive treatment with significant side effects may be avoided.

Infection and eradication of Helicobacter Pylorus affecting etiology and curative effect of idiopathic thrombocytopenic purpura: a META analysis

The study was aimed to explore the relationship between infection of Helicobacter Pylorus (H. Pylorus) and etiology of idiopathic thrombocytopenic purpura (ITP) and evaluate whether H. Pylorus eradication can increase platelet count in patients with ITP. The data-bases of cqvip, Wanfang, TsingHua TongFang, CNKI and PubMed were searched, inclusion and exclusion criteria and heterogeneity test were determined. The studies of H. Pylorus infection and ITP were investigated with fixed effect mode Meta-analysis. Relationship between H. Pylorus infection and etiology of ITP, H. Pylorus eradication and curative effect of ITP were comprehensively and quantitatively evaluated. OR > 1 indicated that factor of exposure was the risk factor of disease; OR < 1 suggested that factor of exposure was the protective factor of disease; OR = 1 revealed that there were no correlation between factor of exposure and diseases. 95%CI was the confidence interval of total OR. The results showed that a total of 211 cases and 210 controls from 5 studies was included to evaluate the exposure of H. Pylorus between ITP patients and controls, the pooled OR was 1.73 (95%CI = 1.12 - 2.67); a total of 458 cases and 305 controls from 13 studies was included to evaluate the relationship between H. Pylorus eradication and curative effect of ITP, the pooled OR was 6.53 (95%CI = 4.44 - 9.61). It is concluded that H. Pylorus infection plays a role in the etiology of ITP. Eradication of H. Pylorus increases platelet count in patients with ITP. H. Pylorus eradication can be used as the first line measure to treat H. Pylorus-positive ITP.

Consequences of Helicobacter pylori infection in children

Although evidence is emerging that the prevalence of Helicobacter pylori (H. pylori) is declining in all age groups, the understanding of its disease spectrum continues to evolve. If untreated, H. pylori infection is lifelong. Although H. pylori typically colonizes the human stomach for many decades without adverse consequences, children infected with H. pylori can manifest gastrointestinal diseases. Controversy persists regarding testing (and treating) for H. pylori infection in children with recurrent abdominal pain, chronic idiopathic thrombocytopenia, and poor growth. There is evidence of the role of H. pylori in childhood iron deficiency anemia, but the results are not conclusive. The possibility of an inverse relationship between H. pylori and gastroesophageal reflux disease, as well as childhood asthma, remains a controversial question. 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.

[Helicobacter pylori infection: from gastric to systemic disease]

H. pylori infection, through a chronic stimulation of the immune system and the occurrence of molecular mimicry mechanisms, is responsible for the majority of the gastroduodenal diseases and also for some extragastric disorders, including sideropenic anemia and idiopathic thrombocytopenic purpura; other diseases are under investigation.

Analysis of B- and T-cell clonality and HLA class II alleles in patients with idiopathic thrombocytopenic purpura: Correlation withHelicobacter pyloriinfection and response to eradication treatment

Many authors have recently found a positive correlation between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP), the most common autoimmune hematological disorder. In order to clarify the pathogenic mechanism of H. pylori-associated ITP, we have investigated 52 consecutive ITP adult patients for Helicobacter pylori infection, B- and T-cell clonality and HLA class II alleles. Thirty-four ITP patients (65.4%) were infected by H. pylori and bacterium eradication was accompanied by a long-term platelet response in 17 (53.1%) of them. A B-cell clonality was found in three patients (5.8%, two patients H. pylori-negative and one patient H. pylori-positive). The ITP patients with H. pylori infection showed a HLA-DRB1*11, *14 and -DQB1*03 frequencies significantly higher and a -DRB1*03 frequency significantly lower than in H. pylori-negative patients. Moreover, an HLA-DQB1*03 pattern was associated with a higher probability of platelet response to eradication treatment. If our study documents the efficacy of eradication treatment in H. pylori-infected ITP patients, it may also help to identify different subgroups of ITP patients with probably different pathogeneses of thrombocytopenia and, finally, different responses to eradication treatment.

[Effect of Helicobacter pylori eradication on childhood acute idiopathic thrombocytopenic purpura]

OBJECTIVE

To evaluate the effect of Helicobacter pylor (Hp) eradication in children with acute idiopathic thrombocytopenic purpura (ITP).

METHODS

Ninety-three children with acute ITP and Hp infection were divided into two groups and treated with prednisone and Hp eradication (group A, 51 cases) or with prednisone without Hp eradication (group B, 42 cases).

RESULTS

The Hp eradication rate was 94.1% in group A. No difference was found in the therapeutic effects on IPT between the two groups, but the recurrence rate in one year in group A was significantly lower than that in group B.

CONCLUSION

NHp eradication does not obviously enhance the therapeutic effect on childhood acute ITP, but can decrease the relapse rate in one year. HP eradication therapy is recommended in children with acute ITP and Hp infection.

[Clinical significance of Helicobacter pylori in pathogenesis of idiopathic thrombocytopenic purpura]

This study was purposed to investigate the infection incidence of Helicobacter pylori (HP) in patients with idiopathic thrombocytopenic purpura (ITP) and curative efficacy of glucocorticoids combined with anti-helicobacter. 100 ITP patients with positive HP were divided randomly into 3 groups: glucocorticoid group (treatment with glucocorticoids, n = 35), anti-HP treatment group (HP eradication, n = 30) and combined treatment group (glucocorticoid combined with HP eradication, n = 35). 100 healthy individuals were selected as control. The results showed that HP infection rate in ITP group was 70%, while HP infection rate in control group (persons received physical examination) was 56%, there was significant difference between two groups (p < 0.05). The HP of 31 cases in combined treatment group was eradicated that the platelet count in 23 out of 31 cases recovered to normal, and in 8 cases was higher than that before treatment, which mean count was (165 +/- 225) x 10(9)/L, this value had statistical significance as compared with that before treatment (p < 0.01). Total efficiency in this group reached to 89%, and relapse rate within 1 year was 8%. The HP infection of 2 cases in glucocorticoid group had been turned to negative naturally, and platelet count recovered to normal, while HP infection in remained 33 cases was still positive. The platelet count in 23 out of 33 cases of that group was not back to normal, but back to normal in 10 cases. The platelet mean count in that group was (78 +/- 26) x 10(9)/L with total efficiency rate of 68% and relapse rate within 1 year was 37%. In the anti-HP treatment group, HP infection in 25 cases was eradicated and platelet count in 9 out of 25 cases recovered to normal, that platelet count in 9 cases was higher than that before treatment, platelet mean count was (135 +/- 174) x 10(9)/L), there was significant difference (p < 0.01), as compared with value before treatment. Total efficiency rate in this group reached to 60%, and relapse rate within 1 year was 33%. It is concluded that the patients with ITP have higher HP infection incidence, and the eradication of HP is effective therapy for the ITP patients with HP infection, which can be used as initial treatment.

Picogram doses of lipopolysaccharide exacerbate antibody-mediated thrombocytopenia and reduce the therapeutic efficacy of intravenous immunoglobulin in mice

Exacerbation of antibody-mediated thrombocytopenia following infection with viruses has recently been demonstrated in a mouse model of the disease. The phenomenon was caused by an increased activation of phagocytes through gamma-interferon secretion in response to infection. Endotoxins from Gram-negative bacteria are also known to be potent activators of phagocytic cells. The objective of the present work was to determine whether lipopolysaccharide (LPS) could exacerbate antibody-mediated thrombocytopenia in vivo and so alter the therapeutic efficacy of intravenous immunoglobulin (IVIg), using a mouse model of thrombocytopenia. Very low doses of LPS (picogram range) and of anti-platelet antibodies (nanogram range), which did not induce thrombocytopenia individually, could synergize in vivo, resulting in significant decreases in platelet counts. The therapeutic efficacy of IVIg in antibody-mediated thrombocytopenia was significantly reduced in presence of LPS. These in vivo observations further support a role for bacterial infections in the aetiology of immune thrombocytopenic purpura (ITP) and may contribute to better understand the recognized lack of efficacy of IVIg in a significant proportion of patients with ITP.

Helicobacter pylori infection and chronic immune thrombocytopenic purpura: long-term results of bacterium eradication and association with bacterium virulence profiles

Eradication of Helicobacter pylori may lead to improvement of chronic immune thrombocytopenic purpura (ITP), although its efficacy over time is uncertain. We report the results of H pylori screening and eradication in 75 consecutive adult patients with ITP. We also used molecular methods to investigate lymphocyte clonality and H pylori genotypes in the gastric biopsies from 10 H pylori-positive patients with ITP and 19 H pylori-positive patients without ITP with chronic gastritis. Active H pylori infection was documented in 38 (51%) patients and successfully eradicated in 34 (89%) patients. After a median follow-up of 60 months, a persistent platelet response in 23 (68%) of patients with eradicated infection was observed; 1 relapse occurred. No differences in mucosal B- or T-cell clonalities were observed between patients with ITP and control participants. Of note, the frequency of the H pylori cagA gene (P = .02) and the frequency of concomitant H pylori cagA, vacAs1, and iceA genes (triple-positive strains; P = .015) resulted statistically higher in patients with ITP than in control participants. All asymptomatic H pylori-positive patients with ITP were suffering from chronic gastritis. Our data suggest a sustained platelet recovery in a proportion of patients with ITP by H pylori eradication alone. Overrepresentation of specific H pylori genotypes in ITP suggests a possible role for bacterium-related factors in the disease pathogenesis.

Helicobacter pylori-associated chronic idiopathic thrombocytopenic purpura and low molecular weight H. pylori proteins

We examined the association between Helicobacter pylori infection and chronic idiopathic thrombocytopenic purpura (cITP) to clarify the development of H. pylori-associated cITP. cITP patients were classified into 3 different groups: Hp-negative (HP-N); Hp-positive, completely or partially responsive to treatment (CR); and Hp-positive and unresponsive to treatment (NR). Reactivity of antibodies to H. pylori before and after eradication was examined by immunoblotting. We used immunoblotting with immunoprecipitation to establish whether platelets form complexes with H. pylori proteins and if these complexes react with patients' sera. CR group showed large (>50 kDa) and low molecular weight protein bands, especially of 36, 27 and 17-kDa. These low molecular weight bands were detected significantly more in the CR group compared to other groups. When healthy human platelets were incubated with H. pylori lysate, they aggregated with the lysate, indicating that complexes were formed between the platelets and the lysate. The complexes immunoprecipitated with anti-human thrombocyte antibodies, and showed a 17 kDa band in the CR, but not in other groups. At least 3 low molecular weight proteins of H. pylori were involved in H. pylori-associated cITP. Immunocomplexes consisting of platelets, low molecular weight proteins of H. pylori and anti-H. pylori antibodies may represent an extra mechanism in development of H. pylori- associated cITP.

Helicobacter pylori infection and thrombocytopenia: a single-institution experience in Mexico

The association between gastrointestinal H. pylori infection and thrombocytopenia was studied in a single institution in Mexico, over a 5-year period. In 99 individuals with H. pylori infection, the prevalence of thrombocytopenia was 14%, whereas in 23 consecutive patients with chronic refractory thrombocytopenic purpura, the prevalence of H. pylori infection was 60%, this figure being similar to that informed in the general population of Mexico (66%); the association between thrombocytopenia and H. pylori infection was not significant. In 14 patients who were found to have both thrombocytopenia and H. pylori infection, eradication treatment was given and the platelet count recovered in three. It is not still clear if detection of H. pylori infection should be routinely included in the initial workup of chronic thrombocytopenia.

Helicobacter pylori and immune thrombocytopenic purpura: unsolved questions and controversies

Immune thrombocytopenic purpura (ITP) is an autoimmune disease mediated by anti-platelet autoantibodies. Recent accumulating evidence indicates that eradication of Helicobacter pylori (H pylori) is effective in increasing platelet count in nearly half of ITP patients infected with this bacterium. The H pylori eradication therapy for adult ITP is becoming very popular in Japan and is now chosen as an initial treatment in H pylori-infected patients. The lack of efficacy of the H pylori eradication regimen in H pylori-negative ITP patients clearly indicates that platelet recovery results from the disappearance of H pylori itself. Despite extensive efforts, clinical features characteristic to H pylori-related ITP and factors predicting the response after the H pylori eradication therapy have not been identified. Great variability in the efficacy of the H pylori eradication therapy in ITP patients exists among countries: a higher response rate has been found in Japan and Italy than in the United States and non-Italian European countries. Some children infected with H pylori show the platelet response after successful eradication of H pylori, but the H pylori eradication therapy is ineffective in patients with secondary ITP. The pathogenesis of ITP associated with H pylori remains obscure; the mechanisms are not simple and may involve multiple steps, including cross-reactivity between H pylori antigen and platelets, and suppression of the reticuloendothelial system. Further studies to evaluate the mechanisms responsible for the platelet response in ITP patients after successful eradication of H pylori may be useful in clarifying the pathogenesis of ITP and developing new therapeutic strategies for ITP.

Effects of a Helicobacter pylori eradication regimen on anti-platelet autoantibody response in infected and uninfected patients with idiopathic thrombocytopenic purpura

Thirty-seven patients with idiopathic thrombocytopenic purpura (ITP) were treated with a standard Helicobacter pylori eradication regimen irrespective of H. pylori infection. Our results indicate that platelet recovery results from the disappearance of H. pylori itself, and is mediated, in part, through suppression of anti-platelet autoantibody production.

Extragastric manifestations of Helicobacter pylori infection--other Helicobacter species

Recent studies have indicated a strong link between Helicobacter pylori and idiopathic thrombocytopenic purpura and iron deficiency anemia. Interesting results have also been obtained for ischemic heart disease, though most putative associations between H. pylori infection and extragastric disease remain speculative. With regard to other Helicobacter species, Helicobacter felis has been shown to play a role in gastric carcinogenesis in mouse models. An increased susceptibility to cholesterol gallstone formation has been described in animals fed a lithogenic diet and infected with Helicobacter bilis, or co-infected with Helicobacter hepaticus and Helicobacter rodentium. Finally, enterohepatic Helicobacter species have also been exploited to better understand inflammatory bowel disease.

The role of Helicobacter pylori infection in children with acute immune thrombocytopenic purpura

The outcome of immune thrombocytopenic purpura (ITP) is classified as acute or chronic depending on whether platelet count returns to normal. The prevalence of Helicobacter pylori infection increases with age and is independent of gender. We investigated the prevalence of H. pylori infection in Chinese children from Northern Taiwan and analyzed the association between H. pylori infection and acute ITP. Our prospective cohort studies found no statistically significant relation between H. pylori infection and acute ITP. There is therefore no indication to screen children with presumed acute ITP for H. pylori infection.

Clonally expanded T-cells in the peripheral blood of patients with idiopathic Thrombocytopenic purpura and Helicobacter pylori infection

Eradication of Helicobacter pylori leads to platelet recovery in some patients with idiopathic thrombocytopenic purpura (ITP). Therefore, the pathogenesis of a subgroup of ITP is probably associated with H pylori infection (H pylori-related ITP). If H pylori-related ITP is a definite subgroup of ITP, specific oligoclonal T-cells might accumulate in the peripheral blood (PB). To address this issue, we performed single-strand conformation polymorphism analysis of complementarity-determining region 3 (CDR3) of the T-cell receptor beta-chain genes of PB T-cells. Fourteen ITP patients with H pylori infection and 12 ageadjusted healthy volunteers were studied. Of the 14 patients, 8 patients (responders) exhibited a platelet response after successful H pylori eradication therapy, but 6 patients (nonresponders) did not. Vbeta5.2, Vbeta15, and Vbeta19 gene usage by clonally expanded T-cells in PB obtained before H pylori eradication therapy was significantly higher in responders than in nonresponders or healthy volunteers (Vbeta5.2, P = .023; Vbeta15, P = .004; Vbeta19, P = .036). Furthermore, an abrogation of clonally expanded T-cells was observed after therapy in some responders. These findings suggest that specific T-cell clones accumulate in H pylori-related ITP and that such clones may be associated with immune-mediated destruction of platelets.

Helicobacter pylori-associated immune thrombocytopenia

Idiopatic thrombocytopenic purpura (ITP), a disorder characterized by autoantibody-mediated platelet destruction, may be primary or secondary to various illnesses including lymphoproliferative, autoimmune, or infectious diseases. There are increasing data on the association between Helicobacter pylori infection and idiopathic thrombocytopenic purpura and the significant increase in platelet count after bacterial eradication. The aim of this review is to consider the studies so far published on Helicobacter pylori infection and idiopathic thrombocytopenic purpura in order to evaluate a possible pathogenic correlation between these two conditions. A review of the literature data show that Helicobacter pylori eradication in patients with idiopathic thrombocytopenic purpura is effective in increasing platelet count in approximately half of the cases. However, since the studies so far published are few, sometimes controversial and involve small series of patients, further controlled studies on larger numbers of patients with longer follow-up are needed to confirm these preliminary findings.

Extragastric manifestations of Helicobacter pylori infection

Since the discovery of Helicobacter pylory (H. pylori), several studies have been published concerning a hypothetical role of this bacterium in different extragastric diseases, such as ischemic heart disease, idiopathic thrombocytopenic purpura, iron deficiency anemia or other disorders. The majority of those studies may be classified as epidemiological or eradicating trials but there are also case reports or in vitro studies. Idiopathic thromobocytopenic purpura represents the disease showing a stronger link with H. pylori infection. There are also increasing evidences on the role of H. pylori infection in iron deficiency anemia and ischemic heart disease. On the contrary, the association between H. pylori infection and other diseases is still controversial, as is supported in the majority of the cases by case reports, small pilot studies or just in vitro data.

High prevalence of sustained remission of idiopathic thrombocytopenic purpura after Helicobacter pylori eradication: a long-term follow-up study

We studied the effect of Helicobacter pylori (H. pylori) eradication in 43 consecutive H. pylori-infected patients with idiopathic thrombocytopenic purpura. H. pylori was eradicated with antibiotics in 41 of them (95.3%). The difference between the mean platelet count before and after therapy was statistically significant (54.3 x 10(9)/l vs. 119.1 x 10(9)/l; P < 0.001). A sustained remission was observed in 20 patients (48.8%), after a median follow-up of 31.2 months. None of the patients still infected by H. pylori after therapy reached normal platelet values. The long-term follow-up confirms the efficacy of H. pylori eradication in H. pylori-infected ITP patients.

Is eradication therapy useful as the first line of treatment in Helicobacter pylori-positive idiopathic thrombocytopenic purpura? Analysis of 207 eradicated chronic ITP cases in Japan

A retrospective study was performed to determine the prevalence of Helicobacter pylori (H pylori) infection, the effect of H pylori eradication on platelet counts, and the characteristic clinical features of chronic immune or idiopathic thrombocytopenic purpura (ITP) with H pylori infection. H pylori infection was found in 300 patients, a group that was significantly older (P < .005) and had more cases of hyperplastic megakaryocytes in the bone marrow (P = .01) than patients without H pylori infection. H pylori eradication therapy was performed in 207 H pylori-positive ITP cases, and the platelet count response was observed in 63% of the successful eradication group and in 33% of the unsuccessful eradication group (P < .005). In the successful group, the complete remission and partial remission rates were 23% and 42%, respectively, 12 months after eradication. In the majority of responders, the platelet count response occurred 1 month after eradication therapy, and the increased platelet count continued without ITP treatment for more than 12 months. H pylori eradication therapy was effective even in refractory cases, which were unresponsive to splenectomy. In conclusion, H pylori infection was involved in most ITP patients older than 40 years in Japan, and eradication therapy should be the first line of treatment in H pylori-positive ITP patients.

Eradication of Helicobacter pylori increases platelet count in patients with idiopathic thrombocytopenic purpura in Japan

BACKGROUND

The effect of Helicobacter pylori eradication on the platelet count in patients with thrombocytopenic purpura is controversial. In this multicentre study, we prospectively assessed the effect of H. pylori eradication therapy in idiopathic thrombocytopenic purpura patients.

MATERIALS AND METHODS

Thirty-five consecutive patients with chronic idiopathic thrombocytopenic purpura (11 males and 24 females, a median age of 57) were assessed for H. pylori infection by use of a urea breath test. All patients received 1-week triple therapy (amoxicillin, clarithromycin, and lansoprazole) to eradicate H. pylori. At 6 months, idiopathic thrombocytopenic purpura patients with a platelet count recovery of greater than 100 x 10(9) L(-1) were defined as idiopathic thrombocytopenic purpura responders.

RESULTS

Helicobacter pylori infection was observed in 25 (71%) of the 35 patients. All infected patients were cured. Eleven patients were identified as idiopathic thrombocytopenic purpura responders; 24 were considered nonresponders. Platelet counts improved by more than 100 x 10(9) L(-1) in 11 (44%) of the 25 patients cured of H. pylori infection, while none of the 10 patients H. pylori-negative patients experienced the same improvement (P = 0.015). Univariate analysis showed that H. pylori infection and its eradication were significant factors associated with platelet recovery (P = 0.015).

CONCLUSIONS

Helicobacter pylori infection played a role in the pathogenesis of idiopathic thrombocytopenic purpura in approximately 30% of all patients assessed and 45% of the patients with H. pylori infection. Eradication of H. pylori in idiopathic thrombocytopenic purpura patients led to improved disease activity.

Effect of Helicobacter pylori eradication on platelet recovery in patients with chronic idiopathic thrombocytopenic purpura

BACKGROUND

A relationship between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) has previously been reported. We determined the prevalence of H pylori infection in Japanese patients with chronic ITP and the effect of its eradication on platelet count.

METHODS

The study population comprised 53 Japanese adults with chronic ITP and a platelet count of less than 100 x 10(3)/ micro L. A (13)C-urea breath test was performed to determine H pylori infection status. Those patients who were H pylori positive gave written informed consent and received eradication therapy. The effect of H pylori eradication on platelet count was evaluated up to 6 months after therapy. Clinical parameters were compared between responders to the therapy (increase in platelet count) and nonresponders, as well as between H pylori-positive and -negative patients.

RESULTS

Of the 53 patients with chronic ITP in the study, 39 (74%) were H pylori positive. Of the 32 infected patients who received treatment, H pylori was successfully eradicated in 27 patients (84%). In 10 (37%) of these patients, this resulted in a favorable platelet response. A partial response was seen in 5 additional patients (19%). A significant (P<.001) increase in platelet count was demonstrated in patients in whom H pylori was successfully eradicated but not in patients who were unsuccessfully treated or in untreated patients. Current corticosteroid therapy was reported more often in nonresponders than in responders.

CONCLUSION

Eradication of H pylori may prove effective in increasing platelet count in H pylori-positive patients with chronic ITP.

Helicobacter pylori eradication: novel therapy for immune thrombocytopenic purpura? A review of the literature

Eradication of Helicobacter pylori (H. pylori ) from the gastric mucosa has been associated with improvement of several systemic diseases, including immune thrombocytopenic purpura (ITP). Over the last 5 years, several studies have reported improved platelet counts in H. pylori-positive ITP patients following standard triple H. pylori eradication therapy. Review of published studies in which eradication of H. pylori has been performed in the ITP population indicates an overall response rate of 52% in 193 subjects in whom H. pylori was eradicated. Cohorts from Japan and Italy report higher response rates. There is no established mechanism to explain how this organism, which does not invade the gastric mucosa, could be implicated in the pathogenesis of this immune-based platelet disorder. Several theories including molecular mimicry, platelet aggregation, and immunomodulatory effects of macrolides have been proposed to explain the platelet response to anti-H. pylori therapy. Large randomized-controlled studies enrolling patients from various ethnic backgrounds will be necessary to determine the response rate and mechanism of response and to gain a better understanding of the pathogenesis of ITP.

Helicobacter pylori Infection and Idiopathic Thrombocytopenic Purpura

A treatment strategy for idiopathic thrombocytopenic purpura (ITP) is considered with the aim of cure or management of the bleeding tendency. In 1998, Gasbarrini et al reported a high prevalence of Helicobacter pylori infection in patients with ITP and showed that platelet recovery occurred after eradication therapy in most cases. Since then, many studies were performed to evaluate eradication therapy. This article discusses the incidence of H pylori infection in ITP, characteristic clinical features in H pylori-positive ITP, the effectiveness of eradication on platelet count increase, and the mechanisms of development of ITP by H pylori infection. Overall, there was a positive association between H pylori infection and ITP, and eradication of bacterium was accompanied by a significant increase in platelet counts in more than 50% of H pylori-positive ITP cases. These findings suggest that H pylori infection is involved in the mechanisms of thrombocytopenia in most cases of ITP in middle-aged and older patients. This approach could be beneficial to some ITP patients, but there were some uncertainties raised. To confirm the effectiveness of eradication therapy in H pylori-positive ITP, prospective studies conducted in several countries with a new treatment protocol are required, with a large number of ITP cases and longer follow-up.

[Evaluation of the efficacy of an Helicobacter pylori eradication treatment for idiopathic thrombocytopenic purpura patients]

The relationship between Helicobacter pylori (H. pylori) and gastric diseases (e.g. peptic ulcer, MALT lymphoma, and stomach cancer) has been widely accepted. Recent studies have also suggested an association between H. pylori infection and idiopathic thrombocytopenic purpura (ITP). In this study, an H. pylori eradication treatment was administered to 20 ITP patients and elucidated for its effectiveness. Among those 20 patients, H. pylori infection was confirmed in 17 (85%) through a C14 urea breath test, a rapid urease test, or a culture examination of a biopsied sample obtained by gastrointestinal endoscopy. Although the other 3 were negative to H. pylori, the H. pylori eradication treatment was also attempted because no other effective treatments had been established at the time of this study. In the H. pylori eradication treatment, lansoprazole (LPZ) 60 mg bid, amoxicillin (AMPC) 1500 mg bid, and clarithromycin (CAM) 400 mg bid were given to each patient for 7 days. For 4 cases, CAM was replaced with metronidazole (MNZ) 750 mg bid. The patients whose H. pylori infection was not eradicated after the first treatment received the re-eradication treatment with LPZ 60 mg bid, AMPC 1500 mg bid, and MNZ 750 mg bid for 7 days. After the treatments, the success of eradicating H. pylori was confirmed in all 17 H. pylori positive patients. In addition, platelet recovery was obtained in 11/20 patients (55%), which included 2 H. pylori negative patients and 2 patients whose H. pylori eradication was not successful after the first treatment. No relationship was found between the eradication effectiveness and the following clinical parameters: age, gender, previous therapies, disease duration, presence of anti-nucleus antibody, endoscopic atrophic change in the stomach, or kinds of antibiotics used for the treatment. These results support the efficacy of an H. pylori eradication treatment for ITP patients. A noteworthy result of this study was that an increase of platelet count was observed not only in H. pylori positive ITP patients, but also in 2 out of 3 H. pylori negative ITP patients after H. pylori eradication. Further studies are required to elucidate the efficacy of H. pylori eradication therapy in the patients negative for H. pylori.

Characteristics of Helicobacter pylori-induced gastritis and the effect of H. pylori eradication in patients with chronic idiopathic thrombocytopenic purpura

BACKGROUND

The association between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) has been reported widely. We investigated the prevalence of H. pylori infection, its virulence profile and the effectiveness of its eradication in patients with ITP.

MATERIALS AND METHODS

Twenty patients with ITP, 20 with peptic ulcer (10 gastric ulcer (GU), 10 duodenal ulcer (DU)) and 20 with NUD were studied. The virulence profile of the strains was assessed by genotyping for cagA, vacA, iceA, and hpyIIIR/hrgA and by assaying for IL-8 and DNA fragmentation after incubation with AGS cells. Infected patients and two uninfected ITP patients received triple therapy and platelets were counted before and 1 month, 6 months, 1 year, and 2 years after eradication therapy.

RESULTS

H. pylori infection was found in 17 ITP (85%), 20 ulcer (100%) and 13 NUD (65%) patients. Biopsies and strains were collected from five ITP, 20 ulcer and 13 NUD patients. The ITP patients had a pangastritis or corpus-predominant gastritis pattern. All H. pylori isolates, from ITP, ulcer and NUD patients, were cagA(+) and vacA s1/m1, and did not differ in levels of IL-8 induction or DNA fragmentation. Fifteen ITP (88%) and 17 ulcer (85%) patients had successful eradication of H. pylori. Ten of these 15 (67%) H. pylori-eradicated ITP patients had platelet recovery. There was no significant change in platelet count in the two ITP patients in whom eradication failed or in the two originally H. pylori-uninfected ITP patients, or in the treated ulcer patients. Age at onset of ITP was the main determinant of platelet recovery: 100% of patients diagnosed after the age of 60 recovered compared with only 22% of those diagnosed before 50.

CONCLUSIONS

H. pylori-infected ITP patients have a corpus-predominant pattern of gastritis but the virulence profile of their strains does not differ from that of ulcer or NUD patients. Eradication of H. pylori infection is a good therapeutic option for some patients with chronic ITP, especially for those who develop ITP in older age.

Acquired amegakaryocytic thrombocytopenia - four cases and a literature review

Acquired amegakaryocytic thrombocytopenla was diagnosed in four dogs. Initial platelet counts in all four dogs were less than 50,000 x 10(9)/litre and initial bone marrow examinations revealed megakaryocytic hypoplasia with minimal changes in the erythroid and myeloid cell lines. Two dogs had evidence of idiopathic immune-mediated disease and two dogs had evidence of associated infectious disease. One dog had a positive antibody titre to Borrella burgdorferi, and one dog had positive titres to both Ehrlichia canis and B. burgdorferi. Treatment consisted of prednisone and cyclophosphamide for the dogs with presumptive immune-mediated disease, and prednisone and tetracycline for the dogs with positive antibody titres to the Infectious organisms. Both dogs with evidence of associated infectious disease responded to treatment. A postmortem examination did not reveal the underlying aetiology in the two dogs with presumptive idiopathic immune-mediated disease.

Helicobacter pylori infection and immune thrombocytopenic purpura: an update

Data are accumulating on the association between Helicobacter pylori infection and idiopathic thrombocytopenic purpura (ITP) and the significant increase in platelet count after bacterial eradication. The aim of this review was to consider the studies so far published on H. pylori infection and ITP in order to evaluate a possible correlation between these two conditions. A review of the literature showed that 278 out of the 482 ITP patients investigated (58%) were positive for H. pylori infection and that the bacterium was eradicated in 88% of cases. Eradication therapy was accompanied by a complete or partial platelet response in approximately half the cases. Overall, these data show that H. pylori eradication in patients with ITP is effective in increasing platelet count. However, because the studies so far published are few, are sometimes controversial and involve small series of patients, further studies on larger numbers of patients with longer follow-up are needed to confirm these preliminary findings.

[Eradication of Helicobacter pylori for idiopathic thrombocytopenic purpura]

We investigated the prevalence of Helicobacter pylori infection and the effect of its eradication in a series of 61 chronic ITP patients. H. pylori infection was found in 53 (86.9%) of 61 ITP patients. H. pylori eradication were performed in 44 infected ITP patients and succeeded in 28 (63.6%) patients. 20 (71.4%) of those 28 patients had platelet recovery and 15 (53.6%) patients achieved a remission, and that effect continue (about 2 years). And we investigated relation with ITP and upper gastrointestinal disease. 2 (3.8%) of 53 H. pylori infected cases were gastric ulcer, 1 (1.9%) was duodenal ulcer and 1 (1.9%) was gastric cancer. All cases were chronic atrophic gastritis, and localized atrophic cases achieved a remission after eradication of H. pylori.

Immune thrombocytopenia attributed to brucellosis and other mechanisms of Brucella-induced thrombocytopenia

Thrombocytopenia often complicates the course of acute brucellosis, mainly due to bone marrow suppression or hypersplenism. Immune thrombocytopenia is also reported in brucellosis, resulting usually in massive thrombocytopenia, purpura, and spontaneous hemorrhage. We describe a case of acute brucellosis in an 85-year old woman, who presented with fever, purpuric skin lesions, anemia, and rhinorrhagia. The absolute platelet count was 1000/microL. Direct and indirect Coombs tests were positive, and a cold-agglutinin was detected. The patient was diagnosed as suffering from brucellosis on the basis of a strongly positive serologic reaction and was treated with doxycycline, streptomycin, and a short course of corticosteroids, with a rapid rise in platelet number.