Items in AFP with MESH term: Transferrin
ABSTRACT: Hereditary hemochromatosis is the most common inherited single-gene disorder in people of northern European descent. It is characterized by increased intestinal absorption of iron, with deposition of the iron in multiple organs. Previously, the classic description was combined diabetes mellitus, cutaneous hyperpigmentation and cirrhosis. Increasingly, however, hereditary hemochromatosis is being diagnosed at an earlier, less symptomatic stage. The diagnosis is based on a combination of clinical, laboratory and pathologic findings, including elevated serum transferrin saturation. Life expectancy is usually normal if phlebotomy is initiated before the development of cirrhosis or diabetes mellitus. Hereditary hemochromatosis is associated with mutations in the HFE gene. Between 60 and 93 percent of patients with the disorder are homozygous for a mutation designated C282Y. The HFE gene test is useful in confirming the diagnosis of hereditary hemochromatosis, screening adult family members of patients with HFE mutations and resolving ambiguities concerning iron overload.
ABSTRACT: Ten percent of the population abuses drugs or alcohol, and 20 percent of patients seen by family physicians have substance-abuse problems, excluding tobacco use. These patients can be identified by relying on regular screening or a high index of suspicion based on "red flags" that can be noted in various clinical situations. The modified CAGE questionnaire is an excellent screening instrument, but several alternatives are available. The best screening test is one that the physician will routinely use well. Laboratory indicators such as gamma-glutamyl transpeptidase, mean corpuscular volume, and carbohydrate-deficient transferrin are nonspecific but can add to the evidence of alcohol abuse. If problem alcohol use is diagnosed, even brief physician advice can be helpful. If the problem has progressed to addiction, referral to an addiction specialist or treatment center is recommended. Special issues arise in dealing with substance abuse in adolescents, elderly patients, and patients with mental illness, but the family physician can play an important role in recognizing this common problem.
Iron Deficiency Anemia - Article
ABSTRACT: The prevalence of iron deficiency anemia is 2 percent in adult men, 9 to 12 percent in non-Hispanic white women, and nearly 20 percent in black and Mexican-American women. Nine percent of patients older than 65 years with iron deficiency anemia have a gastrointestinal cancer when evaluated. The U.S. Preventive Services Task Force currently recommends screening for iron deficiency anemia in pregnant women but not in other groups. Routine iron supplementation is recommended for high-risk infants six to 12 months of age. Iron deficiency anemia is classically described as a microcytic anemia. The differential diagnosis includes thalassemia, sideroblastic anemias, some types of anemia of chronic disease, and lead poisoning. Serum ferritin is the preferred initial diagnostic test. Total iron-binding capacity, transferrin saturation, serum iron, and serum transferrin receptor levels may be helpful if the ferritin level is between 46 and 99 ng per mL (46 and 99 mcg per L); bone marrow biopsy may be necessary in these patients for a definitive diagnosis. In children, adolescents, and women of reproductive age, a trial of iron is a reasonable approach if the review of symptoms, history, and physical examination are negative; however, the hemoglobin should be checked at one month. If there is not a 1 to 2 g per dL (10 to 20 g per L) increase in the hemoglobin level in that time, possibilities include malabsorption of oral iron, continued bleeding, or unknown lesion. For other patients, an endoscopic evaluation is recommended beginning with colonoscopy if the patient is older than 50.
Hereditary Hemochromatosis - Article
ABSTRACT: Hereditary hemochromatosis is an autosomal recessive disorder that disrupts the body’s regulation of iron. It is the most common genetic disease in whites. Men have a 24-fold increased rate of iron-overload disease compared with women. Persons who are homozygous for the HFE gene mutation C282Y comprise 85 to 90 percent of phenotypically affected persons. End-organ damage or clinical manifestations of hereditary hemochromatosis occur in approximately 10 percent of persons homozygous for C282Y. Symptoms of hereditary hemochromatosis are nonspecific and typically absent in the early stages. If present, symptoms may include weakness, lethargy, arthralgias, and impotence. Later manifestations include arthralgias, osteoporosis, cirrhosis, hepatocellular cancer, cardiomyopathy, dysrhythmia, diabetes mellitus, and hypogonadism. Diagnosis requires confirmation of increased serum ferritin levels and transferrin saturation, with or without symptoms. Subtyping is based on genotypic expression. Serum ferritin measurement is the most useful prognostic indicator of disease severity. Liver biopsy is performed to stage the degree of fibrosis with severe ferritin elevation or transaminitis, or to diagnose nonclassical hereditary hemochromatosis in patients with other genetic defects. Treatment of hereditary hemochromatosis requires phlebotomy, and the frequency is guided by serial measurements of serum ferritin levels and transferrin saturation. Iron avidity can result from overtreatment. If iron avidity is not suspected, it may mimic undertreatment with persistently elevated transferrin saturation. Dietary modification is generally unnecessary. Universal screening for hereditary hemochromatosis is not recommended, but testing should be performed in first-degree relatives of patients with classical HFE-related hemochromatosis, those with evidence of active liver disease, and patients with abnormal iron study results. Screening for hepatocellular carcinoma is reserved for those with hereditary hemochromatosis and cirrhosis.