Hemochromatosis

Case report: arthropathy as the presenting symptom in hereditary hemochromatosis

Hemochromatosis is characterized by excessive absorption and subsequent deposition of iron in various organs and is prevalent in 1 out of 20,000 hospitalized patients. Most patients with hereditary hemochromatosis (HHC) become symptomatic between the ages of 50 and 60 years. Distinct forms of arthritis have been associated with HHC and may be the initial clinical manifestation in some patients. This is a case of a patient who had chronic hip and back pain and painless swelling over the knuckles. Radiographs revealed classical signs of HHC. Early recognition and prompt institution of phlebotomy can improve the outcome of patients with HHC.

Portal hypertension and iron depletion in patients with genetic hemochromatosis

Clinically, portal hypertension has been considered to be less common and less severe in patients with cirrhosis resulting from iron overload in homozygotes for genetic hemochromatosis than in patients with cirrhosis of other causes. To characterize the prevalence and progression of portal hypertension in genetic hemochromatosis (GH), 120 cirrhosis and iron-overloaded patients were compared with a control group of 120 patients with postnecrotic cirrhosis (PNC) who were matched for gender, age, Child's class, and alcohol abuse. Gastroesophageal endoscopy and abdominal ultrasonography were performed at diagnosis and repeated every 12 months and every 6 months, respectively, to evaluate the presence and severity of varices, the caliber of the portal vein and its collaterals, and splenic size. At diagnosis a similar frequency of varices was observed in patients with GH (25%) and in PNC (24%), as well as of portal vein abnormalities and spleen enlargement. During the follow-up period, all but two of the patients with GH were treated by phlebotomy and depleted of excess iron. After a mean of 6 +/- 4.3 (SD) years of observations (range, 2 to 10 years), varices were improved or completely reversed in 26% of patients with cirrhosis and GH but in only 5% of those with PNC (P < .01). Bleeding from varices was observed in only one patient with GH but in five patients with PNC. Of 22 patients with GH in whom portal hypertension was unmodified or worsened, 16 had coexistent hepatic viral infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Ironic catastrophes: one's food--another's poison

Iron deficiency is an important nutritional problem in third world countries because it diminishes work performance. In meat-eating countries, iron excess may be more important than iron deficiency. Heme iron is more efficiently absorbed from the diet than inorganic iron, and iron excess can produce cellular oxidation in association with superoxide dismutase. Metal ion catalysis is linked to aging, coronary artery disease, stroke, carcinogenesis, neurodegenerative disorders, and inflammatory disorders. Prudence is advised in the excessive consumption of meat and iron supplementation of the diet until this process is more thoroughly investigated.

Hemochromatosis in Salers cattle

Two 2-year-old Salers cattle from different herds raised on pasture were evaluated for retarded growth and diarrhea. Increase of liver enzyme activities and prolonged sulfobromophothalein (BSP) half life (T1/2) indicated liver disease with impaired liver function. Histopathologic examination of liver biopsies revealed a micronodular cirrhosis with marked deposition of hemosiderin in hepatocytes, Kupffer cells, and arterioles. Transferrin saturation (TS) and liver iron content were markedly increased, consistent with a diagnosis of hemochromatosis. Both animals were euthanatized due to deterioration in their condition. Necropsy findings included hepatomegaly and hemosiderin accumulation in the liver, lymph nodes, pancreas, spleen, thyroid, kidney, brain and other glandular tissue. Continued surveillance of the second herd (serum iron, total iron binding capacity [TIBC], unsaturated iron binding capacity [UIBC], and TS), identified a heifer as a hemochromatosis suspect in a subsequent generation. Liver biopsies from that animal revealed the same histopathologic changes as the previous 2 animals, and similar increases in liver iron content (8,700 ppm, normal range 45 to 300 ppm). The 3 affected cattle were all products of line breeding programs and shared a common ancestor. The absence of dietary iron loading in conjunction with the histopathologic and metabolic findings were consistent with a diagnosis of primary hemochromatosis. The reported disease is similar to idiopathic hemochromatosis in human beings in which there is a hereditary defect in iron metabolism.

Regulation of iron absorption: proteins involved in duodenal mucosal uptake and transport

Newly identified iron (Fe)-binding proteins isolated from both rat and human duodenal mucosa permit a better understanding of Fe absorption. Mucins bind Fe at acid pH to keep it soluble and available for absorption at the more alkaline pH of the duodenum; this explains the development of Fe deficiency in achlorhydric subjects. Integrin was identified on the surface of enterocytes in association with radioiron and is believed to facilitate the transfer of Fe through the microvillous membrane. Mobilferrin, a 56 kDa Fe-binding protein, was identified in enterocyte cytosol. It coprecipitates with integrin and appears in close association with integrin in the apical cytoplasm of absorptive cells. We postulate it accepts dietary Fe from integrin and acts as the shuttle protein from Fe in the cytoplasm. Since Fe in enterocytes remains in equilibrium with body stores, we postulate mucosal Fe uptake is regulated by the number of Fe-binding sites either occupied or unoccupied by Fe on mobilferrin. Fe repletion of enterocytes from body stores is probably accomplished via transferrin receptors on the basal membranes of enterocytes. Increased transfer of Fe from blood into absorptive enterocytes occurs in Fe-replete animals to inhibit mucosal uptake of dietary Fe. Little transfer of Fe from plasma to enterocytes occurs in Fe deficiency. Enhanced mucosal transfer into the body occurs with increased body need for Fe. The exact mechanism for mucosal transfer of Fe into the plasma has not been defined but may also be mediated by an integrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Liver injury and generation of hydroxyl free radicals in experimental secondary hemochromatosis

An experimental model of secondary hemochromatosis is described. Saccharated iron was administered i.v. to rats for 7 months in total doses in the range 1.0-1.7 g per kg body weight. After the completion of iron loading, the biochemical measurements revealed elevation of alanine aminotransferase (ALT), slight reduction of plasma glucose concentration, and significant reduction of both plasma and liver ascorbic-acid levels. The mean liver iron concentration was 50 times higher in iron-loaded animals than in controls. High concentrations of inorganic iron were also observed in spleen, pancreas, and heart. Histologic analysis revealed marked hepatic fibrosis in most animals in the experimental group. These results demonstrate this animal model presents some pathologic findings observed in human transfusional hemochromatosis. Additionally, hydroxyl free radicals were detected by electron paramagnetic resonance (EPR) spectroscopy in the iron-overloaded liver tissue processed at pH 5.0. No free radicals were detected at pH 7.4. These results suggest the possible participation of hydroxyl free radicals in the cellular toxicity of iron overload.

Reversibility of hypogonadotrophic hypogonadism associated with genetic haemochromatosis

OBJECTIVE

Recent reports have suggested that hypogonadotrophic hypogonadism in men with genetic haemochromatosis can be reversed by aggressive venesection therapy. We have studied prospectively men with this complication of haemochromatosis in order to document the frequency and completeness of recovery from hypogonadism.

PATIENTS AND DESIGN

Six men with symptomatic hypogonadotrophic hypogonadism and genetic haemochromatosis were studied before beginning venesection therapy and again after depletion of body iron stores.

MEASUREMENT

Symptoms of hypogonadism, serum gonadotrophins and serum total and free testosterone concentrations.

RESULTS

Five men aged 47-66 showed no symptomatic improvement and no change in serum gonadotrophin or testosterone concentrations. The symptoms of one man, aged 33, resolved completely after venesection and this was accompanied by increases in serum LH and FSH. Serum total and free testosterone concentrations increased fourfold, but remained subnormal.

CONCLUSION

Only one partial recovery from hypogonadotrophic hypogonadism was seen and this was in the youngest subject. In reviewing the other documented cases of reversal it would appear that the age at diagnosis is critical and there are no proven cases of reversal of hypogonadotrophic hypogonadism in men over the age of 40 at the start of venesection therapy.

Survival and prognostic factors in 212 Italian patients with genetic hemochromatosis

Two hundred twelve Italian patients with genetic hemochromatosis (181 men, mean age 50 +/- 11 yr; and 31 women, mean age 49 +/- 10 yr) were followed for a median period of 44 mo (range = 3 to 218 mo). Alcohol abuse was present in 31 subjects (15%), and chronic HBV and HCV infection were seen in 19 (9%) and 35 (24%) of 145 cases tested, respectively. Twenty-four patients (11%) had concomitant beta-thalassemia trait. Liver biopsy revealed cirrhosis in 146 and a noncirrhotic pattern in the other 66. Perls' stain was degree III in 37 patients and IV in 171 patients. One hundred eighty-five patients underwent weekly venesection, and iron depletion was achieved in 122 cases after total iron removal of 3 to 41 gm. Death occurred in 44 patients after 3 to 198 mo and was due to hepatocellular carcinoma in 20 cases, liver failure in 10, extrahepatic cancer in six, heart failure in three and hemochromatosis unrelated causes in five. Cancer has developed in seven other patients still alive (hepatocellular in five and extrahepatic in two). No deaths were observed among noncirrhotic patients; cumulative survival rates in cirrhotic patients were 85%, 75%, 60% and 47% at 3, 5, 8 and 10 yr, respectively. Univariate analysis in the 146 cirrhotic patients showed that age greater than 60 yr, alcohol abuse, cardiomyopathy, skin pigmentation, portal hypertension, hypoalbuminemia, hypergammaglobulinemia and Child class B or C had significant negative prognostic value. At multivariate analysis, only alcohol abuse, gamma-globulins greater than 2.0 gm/dl and Child class B or C maintained their negative prognostic values (p less than 0.01, hazard ratio 2.7; p less than 0.001, hazard ratio 2.8; and p less than 0.001, hazard ratio 4.3, respectively).

Hemochromatosis. It's more than skin-deep

Hemochromatosis is a multisystem disease caused by deposition of iron in tissues and organs. If the disease is discovered early, treatment with phlebotomy increases patient survival time. Because hemochromatosis may be inherited, family members of patients should be examined.

The cytopathology of metal overload

Researchers have been able to demonstrate the cytotoxicity of copper overload in animal models. This has allowed them to not only localize the intracellular distribution of copper but also to study directly the subsequent organelle injury at the ultrastructural level. The lesions seen in copper overload appear to vary from species to species. In humans, marked mitochondrial abnormalities are seen in Wilson's disease while diet overloaded rats show nuclear destruction and various membranous abnormalities. Sequestration of copper within lysosomes appears to protect hepatocytes from its toxicity. However, the mechanism by which the metal is incorporated into lysosomes is not known.