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Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic haemochromatosis is characterised by an inappropriately high rate of iron absorption by the small intestine. The disease is transmitted as an autosomal recessive condition. The gene frequency in the Caucasian population is approximately 1 in 20 and the disease frequency is 1 in 400. Excessive iron deposition occurs in the liver, pancreas, heart, pituitary and joints and hepatic iron concentrations above approximately 400 mumol/g dry weight are always associated with fibrosis and usually with cirrhosis and progressive liver failure. Accurate diagnosis depends upon the demonstration of elevated hepatic iron stores. An hepatic iron index [hepatic iron concentration (in mumol/g dry weight) divided by patient age] of greater than 2.0 distinguishes homozygous subjects from the other conditions in which slight increases in hepatic iron concentration may occur, e.g. in a subject heterozygous for haemochromatosis or alcoholic liver disease. If cirrhosis is present, patients are at a high risk of developing hepatocellular carcinoma. Therefore, they should undergo regular abdominal ultrasound and alpha-fetoprotein estimation. In the absence of cirrhosis, phlebotomy restores life expectancy to normal. Venesection should be continued until all excess iron stores are removed as judged by failure of a rise in haemoglobin concentration on cessation of phlebotomy. Screening of first degree relatives should commence from a young age (e.g. 10 years). If serum ferritin or transferrin saturation are abnormal, liver biopsy should be undertaken. HLA typing of the family allows for the identification of those siblings who are most likely to develop the disease. Secondary iron overload is often multifactorial in origin. Iron chelation therapy with subcutaneous deferoxamine (desferrioxamine) should only commence after careful consideration of the potential benefits in each individual patient.
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PMID:Current concepts in rational therapy for haemochromatosis. 171 64

Iron is essential for life, but iron overload is toxic and potentially fatal. The liver is a major site of iron storage and is particularly susceptible to injury from iron overload, especially when (as in primary hemochromatosis) the iron accumulates in hepatocytes. Iron can be taken up by the liver in several forms and by several pathways including: (1) receptor-mediated endocytosis of diferric or monoferric transferrin or ferritin, (2) reduction and carrier-facilitated internalization of iron from transferrin without internalization of the protein moiety of transferrin, (3) electrogenic uptake of low molecular weight, non-protein bound forms of iron, and (4) uptake of heme from heme-albumin, heme-hemopexin, or hemoglobin-haptoglobin complexes. Normally, pathway 2 is probably the major one for uptake of iron by hepatocytes. Iron is stored in the liver in the cores of ferritin shells and as hemosiderin, an insoluble product derived from iron-rich ferritin. Iron in hepatocytes stimulates translation of ferritin mRNA and represses transcription of DNA for transferrin and transferrin receptors. The major pathologic effects of chronic hepatic iron overload are: (1) fibrosis and cirrhosis, (2) porphyria cutanea tarda, and (3) hepatocellular carcinoma. Although precise pathogenetic mechanisms remain unknown, iron probably produces these and other toxic effects by increasing oxidative stress and lysosomal lability. Vigorous efforts at diagnosis and treatment of iron overload are essential since the pathologic effects of iron are totally preventable by early vigorous iron removal and prevention of iron re-accumulation.
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PMID:Iron and the liver. 184 76

Since an intestinal absorptive interaction between iron and zinc has been described in animals and humans, the possibility of increased accumulation of zinc as well as iron in the liver was studied in patients with hereditary hemochromatosis. Hepatic zinc was determined by atomic absorption spectrophotometry in liver biopsy specimens from 21 homozygotes for hemochromatosis, 21 normal liver samples from autopsies, and 15 cases of cirrhosis unrelated to iron overload. Mean hepatic zinc concentrations in the three groups were compared by one-way analysis of variance. Hemochromatosis patients had hepatic iron determinations by atomic absorption spectrophotometry, and iron absorption studies using 59Fe and total body counting had been previously documented in 18 of the 21 hemochromatosis patients. The mean hepatic zinc was significantly increased at 25.9 +/- 26.7 mumol/g (dry weight) in the hemochromatosis patients, as compared to 4.99 +/- 1.51 mumol/g in the control patients (p less than 0.05), and 2.13 +/- 1.13 mumol/g in the cirrhosis patients without iron overload (p less than 0.05). Hepatic zinc concentration was elevated in hemochromatosis patients who had either normal histology, fibrosis, and cirrhosis. Hepatic zinc concentration was not directly related to patient age, hepatic iron concentration, or iron absorption. In conclusion, hepatic zinc was increased approximately fivefold in patients with hemochromatosis. This finding suggests the concomitant hepatic accumulation of zinc as well as iron in this disorder, possibly by means of increased intestinal absorption of zinc and hepatic sequestration.
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PMID:Hepatic zinc in hemochromatosis. 204 Jan 1

This study reports the findings of hepatic fibrosis and the accumulation of iron in the livers of 12 gerbils. The primary lesion was a haemorrhagic necrosis of the liver that was identical to that produced experimentally in the gerbil by administration of E. coli endotoxin lipopolysaccharide. The resulting extravasation of blood caused focal histiocytic reactions. The number of lesions increased with age, eventually resulting in a micronodular cirrhosis after 9 to 12 months owing to repeated episodes of endotoxin-induced haemorrhages in the liver. The accumulation of iron occurred in perisinusoidal cells, Kupffer cells and hepatocytes. The perisinusoidal cells were responsible for the subsequent hepatic fibrosis. The fibrosis associated with this condition appears to result from iron accumulation in the liver, following haemorrhage caused by endotoxin lipopolysaccharide. The gerbil is the first recorded rodent species to develop hepatic fibrosis in response to hepatic iron overload.
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PMID:Hepatic fibrosis and iron accumulation due to endotoxin-induced haemorrhage in the gerbil. 206 30

Twelve patients (5 women and 7 men, aged from 19 to 54 years) presenting with congenital, non-spherocytic haemolytic anaemia due to erythrocyte pyruvate kinase (PK) deficiency were investigated for systemic iron overload 18 to 27 years after the diagnosis was made. One patient had, beside PK deficiency, idiopathic haemochromatosis demonstrated by the HLA A3 and B14 markers. Another, 21-year old male patient had received more than 100 blood transfusions. In both patients, blood ferritin levels were as high as 5,584 and 9,665 g/litre respectively. Among the remaining 10 patients, 9 had biochemical signs of iron overload, such as high serum iron levels, reduced total siderophilin saturation capacity and blood ferritin levels of about 1,500 g/litre. Hepatic histology could be obtained from 5 patients and showed significant iron overload with cirrhosis in one case and clear-cut portal fibrosis in 3 cases. In all but the patient with multiple transfusions the iron overload was unrelated to transfusions, being present in their absence, usually during the 3rd and 4th decades of their life. The finding of iron overload requires preventive measures such as limitation of transfusions and elimination of iron by deferoxamine therapy.
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PMID:[Iron overload in congenital hemolytic anemia caused by pyruvate kinase deficiency. A major late complication]. 214 11

A 41-year-old hemodialyzed woman developed ascites and was found to have secondary iron overload. The dose of administered iron was approximately 11-12 g, and her serum ferritin level was 15,000 ng/ml (15,000 micrograms/l). There were no signs of congestive heart failure, fluid overload, or liver cirrhosis. A program of weekly phlebotomy combined with recombinant human erythropoietin (rhEPO) therapy was tried to eliminate the iron congestion. After 9 months of this therapy, about 5 g of iron had been removed. The ascites completely disappeared, and her serum ferritin level fell to 5,800 ng/ml (5,800 micrograms/l). This suggests that such combined therapy would be useful when iron overload must be corrected rapidly. Before therapy, the sterile ascitic fluid showed exudative characteristics with 3.7 g/dl (37 g/l) of total protein. The serum-ascites albumin difference was 0.6 g/dl (6 g/l), and the fluid contained 1,400 inflammatory cells/mm3 (1.4 X 10(9)/l). Notably, the serum-ascites albumin difference increased in parallel with iron elimination. These findings suggested that iron deposition may have played a role in changing the permeability of the peritoneum, or in impairing lymphatic drainage, both of which are presumed to be pathogenetic factors of nephrogenic ascites.
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PMID:Treatment of a patient with end-stage renal disease, severe iron overload and ascites by weekly phlebotomy combined with recombinant human erythropoietin. 236 36

Endomyocardial biopsy was performed in 13 patients with primary or secondary iron overload. Prussian blue staining showed visible iron in the biopsy fragments of 8 out of 13 patients. Because of the inhomogeneity of iron deposition in the biopsy fragments, a semi-quantitative myocardial iron grading system was used in which the percentage of Perls' positive cells on 4 to 6 biopsy fragments was averaged from each case. The presence of stainable iron in the myofibrils was not predictable from serum iron, transferrin saturation, serum ferritin or liver iron grading, nor from evidence of endocrine dysfunction. In patients with Perls' positive material in the myocardium, there was a significant correlation between the endomyocardial iron grade and serum iron and transferrin saturation. These results suggest that other factors besides the body iron load determine cardiac iron deposition. The fact that myocardial siderosis was documented only in patients with hepatic cirrhosis, irrespective of the hepatic iron load, suggests that severe liver damage may be a prerequisite for the accumulation of iron in the heart.
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PMID:Myocardial iron grading by endomyocardial biopsy. A clinico-pathologic study on iron overloaded patients. 247 Jun 15

Several inherited forms of iron overload have been described. It is now accepted that HC, usually regarded as a disease of adult life, is an inherited disorder, hence all first degree relatives must be presumed to be at increased risk of developing iron overload and the diagnosis is now frequently made in young relatives. The combination of serum iron, transferrin saturation and serum ferritin determination will detect iron overload in an early, precirrhotic stage. Liver biopsy and the determination of hepatic iron concentration provide the definitive proof. Where HC is recognized sufficiently early to permit adequate removal of iron before cirrhosis has developed, the prognosis is excellent. Thus haemochromatosis as a clinical disease should be preventable in a large proportion of patients. Severe iron overload has been described in juveniles and also in neonates. These conditions are familial but whether they are HLA-related has not been determined. Cardiac and endocrine disorders are frequently the presenting manifestations of parenchymal iron overload in the young and, at least in neonates, the condition is usually fatal in early infancy. It is not possible at present, to say whether these rare juvenile and neonatal forms of haemochromatosis are related to the much more common adult form. Identification of the gene for HC may assist in answering this question.
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PMID:Inherited iron overload. 248 90

Hemochromatosis, or primary iron overload, is a variably expressed genetic metabolic disorder greatly modified by sex, age, diet, and alcohol consumption. Although a diagnosis has been made at the bedside by careful documentation of the slow resolution of subcutaneous iron pigment, clinical diagnosis is frequently overlooked, and even autopsy may fail to reveal hemochromatosis as the cause for cirrhosis. Genetic linkage studies have confirmed the extremely high prevalence of this disorder. Untreated patients may succumb to sepsis caused by organisms such as Vibrio vulnificus, Yersinia species, and others whose virulence is altered by iron availability.
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PMID:Hemochromatosis and infection: alcohol and iron, oysters and sepsis. 248 33

In both hereditary hemochromatosis and in the various forms of secondary hemochromatosis, there is a pathologic expansion of body iron stores due mainly to an increase in absorption of dietary iron. Excess deposition of iron in the parenchymal tissues of several organs (e.g. liver, heart, pancreas, joints, endocrine glands) results in cell injury and functional insufficiency. In the liver, the major pathological manifestations of chronic iron overload are fibrosis and ultimately cirrhosis. Evidence for hepatotoxicity due to iron has been provided by several clinical studies, however the specific pathophysiologic mechanisms for hepatocellular injury and hepatic fibrosis in chronic iron overload are poorly understood. The postulated mechanisms of liver injury in chronic iron overload include (a) increased lysosomal membrane fragility, perhaps mediated by iron-induced lipid peroxidation, (b) peroxidative damage to mitochondria and microsomes resulting in organelle dysfunction, (c) a direct effect of iron on collagen biosynthesis and (d) a combination of all of the above.
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PMID:Hepatic injury in chronic iron overload. Role of lipid peroxidation. 266 96


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