pylori infection and the presence of pernicious anaemia are the leading contenders. In 2008 strategies for preventing gastric cancer

were reviewed Crenolanib mw systematically at the Asia-Pacific Gastric Cancer Consensus Conference [48]. It was concluded that H. pylori screening and eradication in high-risk populations reduced the relative risk of gastric cancer (RR 0·56, 95% CI 0·4–0·8) [44,49]. Other studies have shown that eradication therapy promotes regression and prevents the progression of some precancerous gastric lesions [49,50]. Diagnosis of H. pylori infection cannot be made by serology in CVID patients, but depends on a urea breath test (UBT), faecal antigen immunoassays or endoscopic biopsy. The UBT is the gold standard test. It is widely available, non-invasive, cheap, sensitive (90·3%; 95% CI 83–95) and specific (89·5%; 95% CI 81–95) [51], making it the most suitable for detecting H. pylori infection in CVIDs [52]. The stool test is equally sensitive (sensitivity 68·8–91·7%; specificity 75·6–88·9%) and there is little significant difference in the cost. However, 60% of patients prefer the UBT to the stool test [53]. Because infection is often asymptomatic, detection and eradication of H. pylori at an early stage is appealing. Once eradicated, H. pylori almost

never recurs in the general adult population [54], although it is unknown whether this also applies to patients with CVIDs Gefitinib in vivo who lack protective immunoglobulin (Ig)A at mucosal surfaces. Diagnosis of pernicious anaemia is detected by measuring iron and serum B12 as screening tests for gastritis and vitamin deficiency. Consequently, three simple, non-invasive tests (UBT, serum iron and serum B12) are likely to identify patients with CVIDs who are at the highest risk of gastric cancer in a screening protocol. Regardless of the presence of pernicious anaemia or H. pylori infection, patients with CVIDs still have a 10-fold increased risk [10] for gastric cancer, so can reasonably be regarded as a high-risk population.

Although endoscopic screening of all patients with CVIDs could be considered, a more selective approach is appropriate. We propose (Fig. 1) that all patients diagnosed with CVIDs Sinomenine should undergo screening for H. pylori, using the UBT, at diagnosis. If positive, H. pylori eradication should follow standard practice, with a repeat breath test to demonstrate effective treatment. Because recurrence of infection is exceptional in developed countries [49] a breath test at diagnosis is likely to be sufficient, although data to support this in CVID patients are lacking. In addition, all patients should have serum B12 and iron concentrations measured annually, as pernicious anaemia or gastritis may develop at any age.