Screening for hemochromatosis: recommendation statement

This statement summarizes the U.S. Preventive Services Task Force (USPSTF) recommendation on screening for hemochromatosis and the supporting scientific evidence. The complete information on which this statement is based, including evidence tables and references, is available in the accompanying article in this issue and on the USPSTF Web site (http://www.preventiveservices.ahrq.gov). The USPSTF is redesigning its recommendation statement in response to feedback from primary care clinicians. The USPSTF plans to release, later in 2006, a new, updated recommendation statement that is easier to read and incorporates advances in USPSTF methods. The recommendation statement in this paper is an interim version that combines existing language and elements with a new format. Although the definitions of grades remain the same, other elements have been revised.     

Screening for cardiac dysfunction in asymptomatic patients by measuring B-type natriuretic peptide levels

Early diagnosis and treatment of heart failure lead to improved survival; pre-clinical detection would thus be beneficial. A non-invasive biochemical testing method would indeed be ideal to screen for the condition. In the present study, we sought to determine whether circulating levels of B-type natriuretic peptide (BNP) correlate with cardiac function in asymptomatic subjects. 294 consenting asymptomatic subjects were examined. BNP levels in elevated patients (> 18.4 pg / ml) showed significant correlation with echocardiographic parameters of the systolic and diastolic functions (EF r = -0.51, FS r = -0.50, E/A r = 0.42, p < 0.01). Moderate correlation with the CTR on chest X-ray was also seen (r = 0.23, p < 0.01). Multiple regression analysis showed numerous echocardiographic and hemodynamic parameters including those of systolic and diastolic function in addition to left ventricular wall thickness, blood pressure and serum creatinine levels to be significantly associated with raised BNP levels. Elevated BNP levels reflect cardiac function (both systolic and diastolic) in the asymptomatic population. Detection of cardiac dysfunction by the non-invasive biochemical test may prove useful in early pre-clinical diagnosis of heart failure.     

H63D mutation of the hemochromatosis gene and serum ferritin levels in Thai thalassemia carriers

We determined the prevalence of the H63D and the IVS5#1G-A HFE mutations in 370 (169 males and 201 females) Thai thalassemia carriers and 201 normal subjects. While no IVS5#1G-A mutation was found, the H63D heterozygosity was identified in 5.5% (11/201) of normal subjects and 7.3% (27/370) of thalassemia carriers. Within the thalassemic group, the medians (ranges) of serum ferritin were 217.5 ng/ml (20.1-424.3) and 169.8 ng/ml (3.9-3,536.0) in male subjects and 30.4 ng/ml (11.9-130.7) and 49.3 ng/ml (0.6-931.0) in female subjects with (HD) and without (HH) H63D mutation, respectively. The proportions of subjects with elevated ferritin were found to be 37.5% (6/16) for HD and 14.0% (18/129) for HH in male and 0% (0/11) for HD and 3.0% (5/164) for HH in female subjects, respectively. Statistical analysis of all the data revealed no significant difference. Among 14 Hb E/beta-thalassemia patients, no difference in hematological data as well as serum ferritin levels was observed between those with (HD) and without (HH) H63D mutation. Therefore, the H63D heterozygosity has no significant effect on the serum ferritin level and screening for this HFE mutation in thalassemic patients is not recommended.     

Immunohistochemical evidence for a lack of ferritin in duodenal absorptive epithelial cells in idiopathic hemochromatosis

Patients with idiopathic hemochromatosis exhibit an unexplained increase in intestinal iron absorption. The aim of this work was to study immunohistochemical H- and L-ferritin distribution in duodenal mucosal cells of patients with idiopathic hemochromatosis, and of subjects with various degrees of iron loading. Biopsy sections of gastrointestinal mucosa from 24 patients with idiopathic hemochromatosis, 10 patients with secondary iron overload, 6 normal subjects, and 13 iron-deficient subjects were analyzed with monoclonal antibodies for the presence of immunohistochemical H and L ferritin types, and with Perls' stain for hemosiderin. Ferritin content of duodenal homogenates was evaluated in 5 cases. The absorptive duodenal cells were found to contain ferritin, mostly of the L type, in apical granules; these ferritin granules were present in all normal, iron-deficient, and iron-over-loaded subjects, but were absent in 21 (87%) of the patients with established idiopathic hemochromatosis. In cells other than those of the duodenal epithelium, such as lamina propria or antral mucosa, ferritin and hemosiderin contents were related to iron loading and no difference was evident between primary and secondary iron overload. These findings indicate that (a) idiopathic hemochromatosis is associated with an altered ferritin expression in the duodenal absorptive epithelial cells, (b) this alteration cannot be detected by analysis of duodenal homogenates, (c) idiopathic hemochromatosis does not affect ferritin accumulation in the other cell types analyzed, and (d) ferritin in absorptive duodenal cells may have a regulatory role in iron absorption.     

Screening for hereditary hemochromatosis: a clinical practice guideline from the American College of Physicians

Hereditary hemochromatosis is a genetic disorder of iron metabolism. Diagnosis of hereditary hemochromatosis is usually based on a combination of various genetic or phenotypic criteria. Decisions regarding screening are difficult because of the variable penetrance of mutations of the HFE gene and the absence of any definitive trials addressing the benefits and risks of therapeutic phlebotomy in asymptomatic patients or those with only laboratory abnormalities. The purpose of this guideline is to increase physician awareness of hereditary hemochromatosis, particularly the variable penetrance of genetic mutations; aid in case finding; and explain the role of genetic testing. This guideline provides recommendations based on a review of evidence in the accompanying background paper by Schmitt and colleagues. The target audience for this guideline is internists and other primary care physicians. The target patient population is all persons who have a probability or susceptibility of developing hereditary hemochromatosis, including the relatives of individuals who already have the disease.     

Screening for hemochromatosis in asymptomatic subjects with or without a family history

BACKGROUND: Hemochromatosis in white subjects is mostly due to homozygosity for the common C282Y substitution in HFE. Although clinical symptoms are preventable by early detection of the genetic predisposition and prophylactic treatment, population screening is not currently advocated because of the discrepancy between the common mutation prevalence and apparently lower frequency of clinical disease. This study compared screening for hemochromatosis in subjects with or without a family history. METHODS: We assessed disease expression by clinical evaluation and liver biopsy in 672 essentially asymptomatic C282Y homozygous subjects identified by either family screening or health checks. We also observed a subgroup of untreated homozygotes with normal serum ferritin levels for up to 24 years. RESULTS: Prevalence of hepatic iron overload and fibrosis were comparable between the 2 groups. Disease-related conditions were more common in male subjects identified by health checks, but they were older. Hepatic iron overload (grades 2-4) was present in 56% and 34.5% of male and female subjects, respectively; hepatic fibrosis (stages 2-4) in 18.4% and 5.4%; and cirrhosis in 5.6% and 1.9%. Hepatic fibrosis and cirrhosis correlated significantly with the hepatic iron concentration, and except in cases of cirrhosis, there was a 7.5-fold reduction in the mean fibrosis score after phlebotomy. All subjects with cirrhosis were asymptomatic. CONCLUSIONS: Screening for hemochromatosis in apparently healthy subjects homozygous for the C282Y mutation with or without a family history reveals comparable levels of hepatic iron overload and disease. Significant hepatic fibrosis is frequently found in asymptomatic subjects with hemochromatosis and, except when cirrhosis is present, is reversed by iron removal.     

Screening for hemochromatosis: Patients with liver disease,families, and populations

Hereditary hemochromatosis is a common autosomal-recessive disorder of iron overload usually occurring in individuals who are homozygous for a C282Y mutation in the hemochromatosis (HFE) gene. Current screening methods can detect affected individuals early in disease pathogenesis, enabling early institution of effective treatment that can restore normal life expectancy. Phenotypic screening of adults using transferrin saturation and serum ferritin levels identifies the majority of individuals who develop iron overload. HFE genotyping, when combined with serum biochemical measurements, has reduced reliance on liver biopsy as a diagnostic tool and is the preferred initial screening modality for families with an affected individual. Genetic testing has altered previously held views regarding the high level of penetrance of the disease. Although the majority of C282Y homozygotes develop increased body iron stores, end-organ damage occurs much less frequently than previously thought. Screening is recommended in highrisk groups and in those with a high index of clinical suspicion. Opportunistic screening during routine health assessments may also be recommended. However, large-scale screening of the average-risk population is not recommended on the basis of current evidence.