Helicobacter pylori, iron deficiency, and gastric autoimmunity

How I treat unexplained refractory iron deficiency anemia

Endoscopic gastrointestinal workup fails to establish the cause of iron deficiency anemia (IDA) in a substantial proportion of patients. In patients referred for hematologic evaluation with unexplained or refractory IDA, screening for celiac disease, autoimmune gastritis, Helicobacter pylori, and hereditary forms of IDA is recommended. About 4% to 6% of patients with obscure refractory IDA have celiac disease, and autoimmune gastritis is encountered in 20% to 27% of patients. Stratification by age cohorts in autoimmune gastritis implies a disease presenting as IDA many years before the establishment of clinical cobalamin deficiency. Over 50% of patients with unexplained refractory IDA have active H pylori infection and, after excluding all other causes of IDA, 64% to 75% of such patients are permanently cured by H pylori eradication. In young patients with a history suggestive of hereditary iron deficiency with serum ferritin higher than expected for IDA, mutations involving iron trafficking and regulation should be considered. Recognition of the respective roles of H pylori, autoimmune gastritis, celiac disease, and genetic defects in the pathogenesis of iron deficiency should have a strong impact on the current diagnostic workup and management of unexplained, or refractory, IDA.

Extragastric manifestations of Helicobacter pylori infection

The possible role of Helicobacter pylori as a trigger for some extragastric diseases has been largely investigated in the last year. There are, in fact, several studies concerning cardiovascular diseases, neurological disorders, diabetes mellitus, ear and eyes diseases, immunological and hematological disorders, liver and bile tract diseases, gynecological and respiratory tract pathologies. Among them, idiopathic sideropenic anemia and idiopathic thrombocytopenic purpura still remain the extragastric diseases showing the most convincing results. Concerning ischemic heart disease, there are new interesting data playing in favor of the association, even though there are still some open issues to be clarified. For the other diseases, more studies are needed to clarify the reality of the proposed association.

Helicobacter pylori as a class I carcinogen: physiopathology and management strategies

The gram-negative bacterium Helicobacter pylori is known as a persistent colonizer of the human stomach, and probably less known is that it is also involved in extraintestinal diseases. Public awareness of its contribution in the development of gastric cancer is less than 15 years old. The efficacy of the current therapies based on antibiotics against H. pylori has been limited by difficulties such as antibiotic resistance and recurrence. As a consequence, the development of promising vaccines was prompted as the best preventive measure. Unfortunately, so far vaccines failed the transition from animal models to human trials. This keynote presentation is to provide a bird's eye view of H. pylori-related gastric diseases, including gastric cancer, with a synthesis of the molecular mechanisms involved, and an exhaustive presentation and discussion of the current therapeutic guidelines and future strategies for prevention or therapy.

A hematologist's view of unexplained iron deficiency anemia in males: impact of Helicobacter pylori eradication

BACKGROUND AND OBJECTIVES

Helicobacter pylori infection with, or without coexisting autoimmune gastritis has been implicated in several recent studies as an important cause of IDA in patients with unexplained iron deficiency anemia (IDA). However, the role of H. pylori in the causation of IDA is still unsettled as the vast majority of reported patients were premenopausal women in whom menstrual blood loss was likely the dominant factor determining IDA.

DESIGN AND METHODS

Prospective study of 44 consecutive male IDA patients referred for hematologic evaluation. Following standard endoscopic studies, all patients were screened for non-bleeding GI conditions including celiac disease, autoimmune gastritis and H. pylori gastritis. All subject with H. pylori infection were offered triple therapy for H. pylori eradication.

RESULTS

Only 15 patients had a likely source of blood loss identified. The 29 males with "unexplained" IDA were distinguished by their younger age (36+/-20 vs. 57+/-17 years p<0.001), poor initial response to oral iron treatment, and high prevalence of H. pylori infection (25 of 29 vs. 5 of 15 p<0.0001) with (10) or without (15) coexistent autoimmune gastritis. Three had celiac disease. Following H. pylori eradication, all patients achieved normal hemoglobin levels with follow-up periods ranging from 4 to 69 months (38+/-15 months mean+/-1SD). This was accompanied by a significant decrease in H. pylori IgG antibodies and serum gastrin. Sixteen patients discontinued iron treatment, maintaining normal hemoglobin and ferritin and may be considered cured. Remarkably, 4 of the 16 achieved normal hemoglobin without ever having received oral iron after H. pylori eradication.

INTERPRETATION AND CONCLUSIONS

The favorable long-term clinical results of H. pylori eradication offer strong evidence for a cause-and-effect relation between H. pylori and IDA. Recognition of the respective roles of H. pylori and autoimmune gastritis in the pathogenesis of iron deficiency may have a strong impact on the clinical management of unexplained and refractory iron deficiency anemia.