Helicobacter pylori Infection in Children With Chronic Idiopathic Thrombocytopenic Purpura To the Editor: In the last few years Helicobac- ter pylori is considered to be asso- ciated with a number of autoimmune disorders, such as rheumatoid arthri- tis, atrophic thyroiditis, and adult idiopathic thrombocytopenic purpura, however, the underlying mechanism of H. pylori-induced thrombocyto- penia remains obscure. 1–3 Among the adult patients with chronic idiopathic thrombocytopenic purpura (cITP), the prevalence of H. pylori infection is thought to be relatively high. 2–6 Interestingly, H. pylori eradication has recently been reported as an effective manage- ment for adulthood cITP in patients from Italy and Japan, 2–6 but not in patients from North America 7 and Spain. 8 Although the investigation and eradication of H. pylori infection in children with cITP is a matter of debate, there are a few reports about the children with this disease. 9–11 This prospective study was performed to show the prevalence of H. pylori infection in 31 Iranian children with cITP younger than 14 years, and to determine effects of H. pylori eradica- tion on platelet count. cITP was diagnosed on the basis of presence of isolated thrombocyto- penia (<150  10 9 /L) lasting more than 6 months, without megakaryo- cytic hypoplasia in the bone marrow whereas other causes of thrombocyto- penia were excluded. 12 Of the patients, 17 were girls and 14 were boys, with a mean range of 8.9 years (range: 3.5 to 14). At the time of urea breath test mean platelet counts in all patients were 51.4 ± 34.3  10 9 /L (range: 5  10 9 to 125  10 9 ). The mean dis- ease duration was 27.7 ± 20.2 months (range: 7 to 96). The 13 C-urea breath test (ISO- MAX, Germany) was performed in all patients. To minimize false-nega- tive results, patients had not received antacids, proton pump inhibitors, or antibiotics for at least 2 weeks. This assay has a sensitivity and specificity of 90% to 95% for H. pylori infection. Test results were considered positive when the delta- over-baseline value was greater than 3.5%. 13 H. pylori infection was found in 4 of 31 cITP patients (12.9%) by 13 C-urea breath test. There were no differences in age, platelet counts, or disease duration between H. pylori positive and negative children. Era- dication therapy was started in H. pylori-positive patients using ome- prazole (0.6 mg/kg/d), amoxicillin (50 mg/kg/d), and clarithromycin (15 mg/kg/d) for 2 weeks, at least 1 month after the withdrawal of im- munosuppressive drugs. 13 To assess the efficacy of eradication therapy the urea breath test was repeated 4 weeks after antimicrobial therapy. The in- fection was eradicated in all the H. pylori-positive patients. Then pla- telet count was monitored monthly. We defined a platelet response as either a complete response (rise of platelet count above 150  10 9 /L) or a partial response (rise of greater than 50  10 9 /L relative to baseline). In the present study, from the 4 H. pylori-positive patients none of them achieved complete remission nor partial remission after H. pylori era- dication (Figs. 1–4). To our knowl- edge, 3 H. pylori reports have been published from Taiwan, 9 Finland, 10 and Japan 11 for pediatric patients with cITP. It is difficult to compare the results of these reports because the prevalence of infection or diagnostic methods is different. It is extremely important to remember that, in up to one-third of children with cITP, spontaneous remission will occur months or years later. 12 ITP is an autoimmune disorder with different pathogenetic and clin- ical features in children and adults. Although H. pylori infection can be important in the pathogenesis of thrombocytopenia in some adults with ITP, this may not be the case in children. In our opinion there is insufficient evidence to include a search for H. pylori in the initial workup of cITP children. Further investigations on a large number of children, using a shared diagnostic criteria and a long follow-up, are recommended. Amir Ali Hamidieh, MD* Mohammad Taghi Arzanian, MD* Latif Gachkar, MDw Farahnaz Pasha, MDz Departments of *Pediatric Hematology/Oncology FIGURE 1. Clinical course of case 1. FIGURE 2. Clinical course of case 2. FIGURE 3. Clinical course of case 3. FIGURE 4. Clinical course of case 4. LETTER TO THE EDITOR 96 J Pediatr Hematol Oncol  Volume 30, Number 1, January 2008