Platelet count response to Helicobacter pylori eradication for idiopathic thrombocytopenic purpura in northeastern Brazil

Abstract Background: Several studies have demonstrated that platelet counts in Helicobacter pylori-positive patients with chronic idiopathic thrombocytopenic purpura improved significantly after successful eradication of the infection. However, depending of the geographical region of the study the results have been highly divergent. Objective: The purpose of this study was to evaluate the effect of H. pylori eradication therapy on platelet count in a cohort of chronic idiopathic thrombocytopenic purpura patients from northeastern Brazil. Method: H. pylori status was determined in 28 chronic idiopathic thrombocytopenic purpura patients using the rapid urease test and histology. H. pylori-positive patients received standard triple therapy for one week. The effect of the eradication therapy was evaluated using the 13C-urea breath test two to three months after treatment. Results: The prevalence of H. pylori infection was similar to that found in the general population. Twenty-two patients (78.5%) were H. pylori-positive. Fifteen were treated, 13 (86%) of whom successfully. At six months, 4/13 (30%) displayed increased platelet counts, which remained throughout follow-up (12 months). Platelet response was not associated to mean baseline platelet count, duration of chronic idiopathic thrombocytopenic purpura, gender, age, previous use of medication, or splenectomy. Conclusions: H. pylori eradication therapy showed relatively low platelet recovery rates, comparable with previous studies from southeastern Brazil. The effect of H. pylori eradication on platelet counts remained after one year of follow-up suggesting that treating H. pylori infection might be worthwhile in a subset of chronic idiopathic thrombocytopenic purpura patients.

Helicobacter pylori vacA and cagA genotypes in patients from northeastern Brazil with upper gastrointestinal diseases

Helicobacter pylori causes chronic gastric inflammation and significantly increases the risk of duodenal and gastric ulcer disease and distal gastric carcinoma. In this study, we evaluated the Helicobacter pylori vacA and cagA genotypes in patients from a Brazilian region where there is a high prevalence of gastric cancer. Polymerase chain reaction (PCR) was used to investigate vacA mosaicism and cagA status in the gastric mucosa of 134 H. pylori-positive patients, including 76 with gastritis: 28 with peptic ulcer disease and 30 with gastric cancer. The s1m1 variant was the predominant vacA genotype observed, whereas the s1 allele was more frequently observed in patients with more severe diseases associated with H. pylori infection [p = 0.03, odds ratio (OR) = 5.72, 95% confidence interval (CI) = 1.15-38.60]. Furthermore, all of the s1 alleles were s1b. Mixed vacA m1/m2 strains were found more frequently in patients with gastric cancer and a cagA-positive status was significantly associated with gastric cancer (p = 0.016, OR = 10.36, 95% CI = 1.35-217.31). Patients with gastric cancer (21/21, 100%, p = 0.006) or peptic ulcers (20/21, 95%, p = 0.02) were more frequently colonised by more virulent H. pylori strains compared to gastritis patients (41/61, 67.2%). In conclusion, in the northeastern of Brazil, which is one of the regions with the highest prevalence of gastric cancer in the country, infection with the most virulent H. pylori strains, carrying the cagA gene and s1m1 vacA alleles, predominates and is correlated with more severe H. pylori-associated diseases.