الفهرس 
NORMAL IRON METABOLISMOnly 14 pages are availabe for public view
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Abstract
I
ron is one of the most widely spread metals in the earth’s crest and it is essential for almost all forms of life.
In normal individuals, iron homeostasis is meticulously regulated to avoid deleterious extremes of iron deficiency and iron overload.
Iron deficiency is estimated to be the most common nutritional deficiency in both developed and underdeveloped nations, the most common cause of anemia. Iron deficiency is affecting an estimated 500 to 600 million individuals. In Egypt, iron deficiency anemia is presumed to be 80% of all anemias.
Iron status can be assessed through several laboratory tests including hematological tests based on characteristics of red blood cells (i.e., Hb concentration, hematocrit, mean cell volume, and red blood cell distribution width) and biochemical tests (i.e., erythrocyte protoporphyrin concentration, serum ferritin concentration, and transferrin saturation).
Established causes of iron deficiency include inadequate iron intake, chronic blood loss, malabsorption, hemolysis , or a combination of these factors. In the absence of poor dietary intake or ongoing obvious blood loss, any patient who presents with iron deficiency anemia needs to undergo extensive gastrointestinal tract evaluation to look for presence of an ongoing bleeding lesion.
The failure to identify a cause of iron deficiency in a substantial subset of patients with low iron stores raises the question of whether there are additional as of yet unexplained causes of iron depletion. Recently, there has been a growing body of evidence to suggest a relationship between Helicobacter pylori gastritis and iron deficiency anemia in the absence of peptic ulcer disease.
Helicobacter pylori infection is a worldwide disease with a significant morbidity and mortality where Over 50% of the people in the world are infected by H.pylori. In developing countries, H.pylori infection reaches 70%-90% of the populations.
H. pylori has been linked with the development of gastritis, peptic ulcer, gastric cancer and MALT-lymphoma. Recent studies have shown that H. pylori can also cause other extragastric diseases like hepatocellular carcinomas, primary biliary cirrhosis, bronchial asthma, lung cancer, urticaria and ITP. Infection is usually acquired during childhood and is associated with sociodemographic factors such as low socioeconomic status, poor hygiene and crowding.
Diagnosis of Helicobacter pylori can be made with both invasive and noninvasive tests. The invasive tests require endoscopy to obtain biopsies of the gastric mucosa for histology, culture and rapid urease test. On the other hand , noninvasive tests are based on analysis of samples of breath, blood, or stool. These non-invasive tests are characterized by their simplicity, low cost, speed, and minimal patient discomfort.
The aim of this work was to study the association between unexplained iron deficiency anemia and Helicobacter pylori infection and to assess the association between the severity of iron deficiency anemia and Helicobacter pylori infection.
The study was carried out on 40 patients with unexplained iron deficiency anemia and 20 apparently healthy individuals. The H.pylori was detected in the patients’ sera by using ELISA technique, in addition to H.pylori antigen detection in stool of 20 patients of them. Patients who had an obvious cause of iron deficiency, such as ongoing GI or non-GI blood loss, pregnancy, lactation, use of steroids, non-steroidal anti-inflammatory drugs or alcohol were excluded. None of the patients had any site-specific gastrointestinal symptoms (symptoms that could be traced to either the upper or lower gastrointestinal tract) or had occult blood in stool.
The ELISA antibody test revealed 24/40 Helicobacter pylori positive cases and 16/40 negative cases. Otherwise the stool antigen test revealed 17/20 positive cases and 3/20 negative cases. So, we found that H pylori infection was independently associated with unexplained iron deficiency anemia with an estimated prevalence 60% (24/40) among studied patients; 47.5% (19/40) in females and 12.5% (5/40) in males.
Concerning the demographic (age, gender) features, they revealed insignificant difference between seropositive and seronegative groups. Also, no significant difference was found between positive and negative subjects as regards Hb, MCV, MCH and MCHC.
In our study, it was found that Helicobacter pylori IgG positive subjects had significantly lower serum ferritin levels than Helicobacter pylori negative subjects. This indicated severe anemia and more affection of iron status in the H. pylori infected persons.
In the present research, H. Pylori IgG test had sensitivity 60 %, specificity 95 %, positive predictive value 96%, negative predictive value 54.3% and diagnostic accuracy71.7% in the diagnosis of helicobacter pylori infection when we used the cut-off of positivity of the manufacture (20U/ml).
By using (ROC) curve, a new cut-off (10U/ml) was the best cut-off in which the sensitivity raised to 90% but the specificity decreased to 75%. The positive predictive value became 87.8%, negative predictive value was turned to 78.9% and diagnostic accuracy elevated to 85%.This was better as screening test at a cut-off (10U/ml) with high sensitivity (90%). For better specificity (95%), a cut-off (20U/ml) should be considered.
Our results showed that there was significant correlation observed between H.pylori Ab titre and low Hb, low MCV, Retics, low serum ferritin, low serum Iron and high TIBC.
Our analysis showed that there was no agreement between serologic test results and stool antigen test.
In summary, there is evidence to support significant influence of H. pylori infection on body iron stores. Our study provides further data that patients with unexplained IDA benefit from testing and treatment for H. pylori infection. Given the relative ease and simplicity of H. pylori treatment and the encouraging results in literature, H. pylori testing and treatment for persons with unexplained IDA appears to be clinically indicated.