Coincidental hemochromatosis and viral hepatitis

Speciation of iron in mouse liver during development, iron deficiency, IRP2 deletion and inflammatory hepatitis

The iron content of livers from (57)Fe-enriched C57BL/6 mice of different ages were investigated using Mössbauer spectroscopy, electron paramagnetic resonance (EPR), electronic absorption spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS). About 80% of the Fe in an adult liver was due to blood; thus removal of blood by flushing with buffer was essential to observe endogenous liver Fe. Even after exhaustive flushing, ca. 20% of the Fe in anaerobically dissected livers was typical of deoxy-hemoglobin. The concentration of Fe in newborn livers was the highest of any developmental stage (∼1.2 mM). Most was stored as ferritin, with little mitochondrial Fe (consisting primarily of Fe-S clusters and haems) evident. Within the first few weeks of life, about half of ferritin Fe was mobilized and exported, illustrating the importance of Fe release as well as Fe storage in liver function. Additional ferritin Fe was used to generate mitochondrial Fe centres. From ca. 4 weeks of age to the end of the mouse's natural lifespan, the concentration of mitochondrial Fe in liver was essentially invariant. A minor contribution from nonhaem high-spin Fe(II) was observed in most liver samples and was also invariant with age. Some portion of these species may constitute the labile iron pool. Livers from mice raised on an Fe-deficient diet were highly Fe depleted; they were devoid of ferritin and contained 1/3 as much mitochondrial Fe as found in Fe-sufficient livers. In contrast, brains of the same Fe-deficient mice retained normal levels of mitochondrial Fe. Livers from mice with inflammatory hepatitis and from IRP2(-/-) mice hyper-accumulated Fe. These livers had high ferritin levels but low levels of mitochondrial Fe.

The nuclear factor kappa-B signaling pathway as a therapeutic target against thyroid cancers

BACKGROUND

The nuclear factor kappa-B (NF-κB) proteins, a family of transcription factors found virtually in all cells, are known to play crucial roles in the growth of a number of human malignancies. The ability of NF-κB to target a large number of genes that regulate cell proliferation, differentiation, survival, and apoptosis, provides clues toward its deregulation during the process of tumorigenesis, metastatic progression, and therapeutic resistance of tumors.

SUMMARY

In addition to the signaling pathways known to be involved in thyroid tumorigenesis, such as the mitogen-activated protein kinase and janus kinase cascades, studies implicate the NF-κB pathway in the development of both less aggressive thyroid cancers, papillary and follicular adenocarcinomas, and progression to aggressive thyroid cancers, such as anaplastic adenocarcinomas. A constitutively activated NF-κB pathway also closely links Hashimoto's thyroiditis with increased incidence of thyroid cancers. The NF-κB pathway is becoming one of the major targets for drug development, and a number of compounds have been developed to inhibit this pathway at different levels in cancer cells. Some of these targets have shown promising outcomes in both in vitro and in vivo investigations and a handful of them have shown efficacy in the clinical setting.

CONCLUSIONS

This review discusses the recent findings that demonstrate that the inhibition of NF-κB, alone or with other signaling pathway inhibitors may be of significant therapeutic benefits against aggressive thyroid cancers.

Transfusion iron overload in adults with acute leukemia: manifestations and therapy

BACKGROUND

Hepatic dysfunction occurs commonly among persons successfully treated for acute leukemia, and iron overload is a possible cause of hepatic and other abnormalities in these patients.

METHODS

We identified 5 adults 40+/-13 (mean +/- S.D.) years of age who developed transfusion iron overload in association with successful chemotherapy of de novo acute leukemia. None had evidence of hemochromatosis, viral hepatitis, or other primary hepatic disorders.

RESULTS

The mean serum ferritin concentration of our patients was 1531+/-572 ng/mL. Other abnormalities associated with transfusion iron overload were increased stainable iron in bone marrow macrophages, elevated serum concentrations of hepatic enzymes, hyperpigmentation, hyperferremia, elevated iron saturation of serum transferrin, and increased stainable iron in Kupffer cells and hepatocytes. Rheumatologic, endocrinologic, or cardiac abnormalities attributable to iron overload were not observed. Therapeutic phlebotomy was initiated after chemotherapy; recovery of hemoglobin concentrations after phlebotomy permitted weekly treatment in each case. This yielded an average of 28+/-9 units per patient (range 15-35 units). Abnormalities associated with transfusion iron overload resolved after iron depletion therapy. The mean leukemia-free survival of our patients is 96+/-36 months (range 40-125 months).

CONCLUSIONS

Our data and those of others suggest that 15 to 20% of adults who are long-term survivors of acute leukemia develop iron overload, often with hepatic abnormalities. Iron overload is a relatively common sequela to successful management of acute leukemia in adults for which routine evaluation should be performed and for which therapeutic phlebotomy should be used as treatment.

Practice guideline development task force of the College of American Pathologists. Hereditary hemochromatosis

Hereditary hemochromatosis is an autosomal recessive disorder, the gene for which occurs in approximately 10% of Americans, most of whom are unaffected heterozygotes. Approximately 5/1000 white Americans are homozygous and at risk of developing severe and potentially lethal hemochromatosis. The disorder affects numerous organ systems, but the most common symptoms are fatigue, palpitations, joint pains, and impotence; the most common signs are those that relate to hypothalamic, cardiac, hepatic or pancreatic dysfunction, including poor cold tolerance, impotence in males, amenorrhea in females, cardiac arrhythmias, dyspnea, edema, hepatosplenomegaly, spider telangiectases, ascites, deformity, swelling or limitation of motion of joints, weight loss, hyperpigmentation. Characteristic abnormalities of laboratory tests include elevated serum iron concentration, high transferrin saturation, elevated serum ferritin concentration, elevated serum transaminases, hyperglycemia and low values for thyroid-stimulating hormone (TSH) and gonadotropins. Death may be the result of cardiac arrhythmia, congestive heart failure, liver failure or liver cancer. Since many of these complications cannot be reversed once they have developed, early diagnosis and treatment are essential. In view of the high prevalence in the American population (prevalence varies with ethnic background), the low cost of diagnosis and treatment, the efficacy of treatment if begun early, and, on the other hand, high costs and low success rate of late diagnosis and treatment, systematic screening for hemochromatosis is warranted for all persons over the age of 20 years. The initial screening should be by measurement of serum iron concentration and transferrin saturation. The practice guideline provides a diagnostic algorithm for cases in which the serum transferrin saturation is 60% or greater. It also provides guidelines for clinical management.