Immunosuppressive effects of melanoma-derived heavy-chain ferritin are dependent on stimulation of IL-10 production

Cultured melanoma cells release soluble factors that influence immune responses. Screening of a cDNA library with anti-sera from a melanoma patient identified an immunoreactive plaque, which encoded heavy-chain ferritin (H-ferritin), Previous studies have drawn attention to the immunosuppressive effects of this molecule and prompted further studies on its biochemical and functional properties in human melanoma, These studies demonstrated, firstly, that H-ferritin appeared to be secreted by melanoma cells, as shown by immunoprecipitation of a 21.5 kDa band from supernatants. It was also detected in extracts of melanoma cells by Western blotting as 43 and 64 kDa dimers and trimers of the 21.5 kDa fraction. Secondly, flow-cytometric analysis of H- and light-chain ferritin (L-ferritin) expression on melanoma showed a wide variation in L-ferritin expression and consequently of the ratio of H- to L-ferritin expression. Suppression of mitogenic responses of lymphocytes to anti-CD3 showed a correlation with the ratio of H- to L-ferritin in the supernatants and was specific for H-ferritin, as shown by inhibition studies with a monoclonal antibody (MAb) against H-ferritin, Similar results were obtained with H- and L-ferritin from other sources. Suppression of mitogenic responses of lymphocytes to anti-CD3 by H-ferritin was inhibited using a MAb against IL-IO, which suggested that the immunosuppressive effect of H-ferritin was mediated by IL-IO, Assays of cytokine production from anti-CD3-stimulated lymphocytes showed that H-ferritin markedly increased production of IL-10 and IFN-gamma and had only slight effects on IL-2 and IL-4 production, Our results suggest that melanoma cells may be a major source of H-ferritin and that production of the latter may account for some of the immunosuppressive effects of melanoma, (C) 2001 Wiley-Liss. Inc.

Diagnosis of iron deficiency anemia in children of Northeast Brazil

OBJECTIVE: To diagnose iron deficiency anemia in children. METHODS: The study was conducted with a sample of 301 children aged six to 30 months attending public daycare centers in the city of Recife, Northeast Brazil, in 2004. The diagnoses of anemia were based on a combination of different hematological and biochemical parameters: hemoglobin, mean corpuscular volume, ferritin, C-reactive protein, transferrin saturation and transferrin receptor. The chi-square test and ANOVA were used in the statistical analysis. RESULTS: Of all children studied, 92.4% had anemia (Hb <110 g/L) and 28.9% had moderate/severe anemia (Hb <90 g/L). Lower levels of hemoglobin were found in children aged 6-17 months. Iron deficiency was found in 51.5% of children using ferritin (<12 μg/L) as parameter. Taking into consideration the combination of hemoglobin level, ferritin and transferrin receptor, 58.1% had anemia with iron deficiency, 34.2% had anemia without iron deficiency and 2.3% had iron deficiency without anemia. Mean ferritin concentration was significantly higher in children with high C-reactive protein when compared with those with normal levels (22.1 vs. 14.8 µg/L). CONCLUSIONS: The use of several biochemical and hematological parameters allowed to diagnosing iron deficiency anemia in two thirds of children, suggesting a need to identify other determinants of anemia without iron deficiency.

Effect of C282Y Genotype on Self-Reported Musculoskeletal Complications in Hereditary Hemochromatosis

OBJECTIVE: Arthropathy that mimics osteoarthritis (OA) and osteoporosis (OP) is considered a complication of hereditary hemochromatosis (HH). We have limited data comparing OA and OP prevalence among HH patients with different hemochromatosis type 1 (HFE) genotypes. We investigated the prevalence of OA and OP in patients with HH by C282Y homozygosity and compound heterozygosity (C282Y/H63D) genotype. METHODS: A total of 306 patients with HH completed a questionnaire. Clinical and demographic characteristics and presence of OA, OP and related complications were compared by genotype, adjusting for age, sex, body mass index (BMI), current smoking and menopausal status. RESULTS: In total, 266 of the 306 patients (87%) were homozygous for C282Y, and 40 (13%) were compound heterozygous. The 2 groups did not differ by median age [60 (interquartile range [IQR] 53 to 68) vs. 61 (55 to 67) years, P=0.8], sex (female: 48.8% vs. 37.5%, P=0.18) or current smoking habits (12.4% vs. 10%, P=0.3). As compared with compound heterozygous patients, C282Y homozygous patients had higher median serum ferritin concentration at diagnosis [1090 (IQR 610 to 2210) vs. 603 (362 to 950) µg/L, P<0.001], higher median transferrin saturation [80% (IQR 66 to 91%) vs. 63% (55 to 72%), P<0.001]) and lower median BMI [24.8 (22.1 to 26.9) vs. 26.2 (23.5 to 30.3) kg/m2, P<0.003]. The overall prevalence of self-reported OA was significantly higher with C282Y homozygosity than compound heterozygosity (53.4% vs. 32.5%; adjusted odds ratio [aOR] 2.4 [95% confidence interval 1.2-5.0]), as was self-reported OP (25.6% vs. 7.5%; aOR 3.5 [1.1-12.1]). CONCLUSION: Patients with C282Y homozygosity may be at increased risk of musculoskeletal complications of HH.

Functional and structural studies of a mini-ferritin protein

Dissertação para obtenção do Grau de Mestre em Bioquímica

Carences en vitamine B12 et fer: du diagnostic au suivi [Vitamin B12 and iron deficiencies: from diagnostic to follow-up].

Vitamin B12 and iron deficiencies are common problems in consultations of general internal medicine. They cause different symptoms that can be non-specific. This article makes it possible, from a clinical frame of reference, to answer the following questions: What value of vitamin B12 should we consider a "deficiency", and what is the role of methylmalonate? What is the role of vitamin B12 oral supplements? How should we interpret values of ferritine? How should iron deficiency be investigated? What is the place of intravenous iron administration?

Aggregate cultures of foetal rat liver cells: development and maintenance of liver gene expression.

Rotation-mediated aggregate cultures of foetal rat liver cells were prepared and grown in a chemically defined medium. Their capacity for cellular organisation and maturation was studied over a culture period of 3 wk by using both morphologic and biochemical criteria. It was found that within each aggregate, distinct liver cell types were present and attained their normal, differentiated phenotype. Parenchymal cells formed small acini with a central lumen. Within the first 2 wk in culture, albumin and ferritin mRNA levels were maintained, while the alpha-fetoprotein mRNA levels decreased, and tyrosine aminotransferase (TAT) gene expression increased. No significant response to glucocorticoids was observed in early cultures, whereas after 3 wk a marked increase in TAT mRNA levels was elicited by dexamethasone and glucagon (additive stimulatory effects). The results show that foetal rat liver cells cultured in a chemically defined medium are able to rearrange themselves into histotypic structures, and display a developmental pattern of gene expression comparable to that of perinatal rat liver in vivo. This culture system offers therefore a useful model to study the development and function of liver cells.

Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomised placebo controlled trial.

OBJECTIVE: To determine the subjective response to iron therapy in non-anaemic women with unexplained fatigue. DESIGN: Double blind randomised placebo controlled trial. SETTING: Academic primary care centre and eight general practices in western Switzerland. PARTICIPANTS: 144 women aged 18 to 55, assigned to either oral ferrous sulphate (80 mg/day of elemental iron daily; n=75) or placebo (n=69) for four weeks. MAIN OUTCOME MEASURES: Level of fatigue, measured by a 10 point visual analogue scale. RESULTS: 136 (94%) women completed the study. Most had a low serum ferritin concentration; <or= 20 microg/l in 69 (51%) women. Mean age, haemoglobin concentration, serum ferritin concentration, level of fatigue, depression, and anxiety were similar in both groups at baseline. Both groups were also similar for compliance and dropout rates. The level of fatigue after one month decreased by -1.82/6.37 points (29%) in the iron group compared with -0.85/6.46 points (13%) in the placebo group (difference 0.95 points, 95% confidence interval 0.32 to 1.62; P=0.004). Subgroups analysis showed that only women with ferritin concentrations <or= 50 microg/l improved with oral supplementation. CONCLUSION: Non-anaemic women with unexplained fatigue may benefit from iron supplementation. The effect may be restricted to women with low or borderline serum ferritin concentrations.

Prevalence of anaemia in inflammatory bowel disease in Switzerland: a cross-sectional study in patients from private practices and university hospitals.

BACKGROUND: Anaemia represents a common complication of inflammatory bowel disease (IBD). Most studies on anaemia in IBD patients have been performed in tertiary referral centres (RC) and data from gastroenterologic practices (GP) are lacking. We investigated the frequency and severity of anaemia in IBD patients from tertiary referral centres and gastroenterologic practices compared to the general population. METHODS: Data were acquired from patients included in the Swiss IBD Cohort Study. IBD activity was evaluated by CDAI and modified Truelove and Witts severity index (MTWSI). Anaemia was defined as haemoglobin ≤120g/L in women and ≤130g/L in men. RESULTS: 125 patients from RC (66 with Crohn's disease (CD) and 59 with ulcerative colitis (UC)) and 116 patients from GP (71 CD and 45 UC) were included and compared to 6074 blood donors. Anaemia was found in 21.2% (51/241) of the IBD patients and more frequently in patients from RC as compared to GP and healthy controls (28.8% vs. 12.9% vs. 3.4%; P<0.01). IBD patients from RC suffered more frequently from active disease compared to IBD patients in GP (36% vs. 23%, P=0.032). Supplementation therapy (iron, vitamin B12, folic acid) was performed in 40% of anaemic IBD patients in GP as compared to 43% in RC. CONCLUSIONS: Anaemia is a common complication in patients with IBD and significantly more prevalent in patients from referral centres as compared to patients from gastroenterologic practices. Physicians treating IBD patients should pay attention to the presence of anaemia and ensure sufficient supplementation therapy.

Eliminating heterophilic antibody interference for ferritin detection using Olympus F(ab')2 based reagent.

Interferences with the Olympus immunoturbidimetric assay for ferritin have been reported because the antibodies used in the immunoassay are derived from rabbits. Rabbits are familiar pets known to be a risk factor for developing heterophilic (or interfering) antibodies. This report shows how the current Olympus Ferritin assay has been improved to eliminate the interference from heterophilic antibodies.

Serum ferritin levels are associated with a distinct phenotype of chronic hepatitis C poorly responding to pegylated interferon-alpha and ribavirin therapy.

Elevated serum ferritin levels may reflect a systemic inflammatory state as well as increased iron storage, both of which may contribute to an unfavorable outcome of chronic hepatitis C (CHC). We therefore performed a comprehensive analysis of the role of serum ferritin and its genetic determinants in the pathogenesis and treatment of CHC. To this end, serum ferritin levels at baseline of therapy with pegylated interferon-alpha and ribavirin or before biopsy were correlated with clinical and histological features of chronic hepatitis C virus (HCV) infection, including necroinflammatory activity (N = 970), fibrosis (N = 980), steatosis (N = 886), and response to treatment (N = 876). The association between high serum ferritin levels (> median) and the endpoints was assessed by logistic regression. Moreover, a candidate gene as well as a genome-wide association study of serum ferritin were performed. We found that serum ferritin ≥ the sex-specific median was one of the strongest pretreatment predictors of treatment failure (univariate P < 0.0001, odds ratio [OR] = 0.45, 95% confidence interval [CI] = 0.34-0.60). This association remained highly significant in a multivariate analysis (P = 0.0002, OR = 0.35, 95% CI = 0.20-0.61), with an OR comparable to that of interleukin (IL)28B genotype. When patients with the unfavorable IL28B genotypes were stratified according to high versus low ferritin levels, SVR rates differed by > 30% in both HCV genotype 1- and genotype 3-infected patients (P < 0.001). Serum ferritin levels were also independently associated with severe liver fibrosis (P < 0.0001, OR = 2.67, 95% CI = 1.68-4.25) and steatosis (P = 0.002, OR = 2.29, 95% CI = 1.35-3.91), but not with necroinflammatory activity (P = 0.3). Genetic variations had only a limited impact on serum ferritin levels. Conclusion: In patients with CHC, elevated serum ferritin levels are independently associated with advanced liver fibrosis, hepatic steatosis, and poor response to interferon-alpha-based therapy.

Hyperferritinémie associée au syndrome métabolique: une nouvelle cible thérapeutique [Dysmetabolic hyperferritinemia: a new target for treatment?].

Dysmetabolic hyperferritinemia is currently the most frequent cause of elevated ferritin levels in the general population. Whether dysmetabolic hyperferritinemia is a cause or an effect of insulin resistance is still a matter of debate. Still, several findings have been well established: increased iron intake or elevated ferritin levels are individual risk factors for diabetes, metabolic syndrome or gestational diabetes. When in presence of dysmetabolic hyperferritinemia, a small number of randomized controlled trials have suggested that therapeutic measures aimed at reducing ferritin levels such as low red meat consumption, deferoxamin or therapeutic phlebotomies have shown a beneficial effect on glucose homeostasis, lipid profile and impaired hepatic markers observed in non-alcoholic steatohepatitis.

Glial and axonal body fluid biomarkers are related to infarct volume, severity, and outcome.

Body fluid biomarkers of central nervous system damage may help improve the prognostic and diagnostic accuracy in ischemic stroke. We studied 53 patients. Stroke severity and outcome was rated using the National Institutes of Health Stroke Scale and modified Rankin scale. Ferritin, S100B, and NfH were measured in cerebrospinal fluid (CSF) and serum. Infarct volume was calculated from T2W images. CSF S100B (median 1.00 ng/mL) and CSF ferritin (10.0 ng/mL) levels were elevated in patients with stroke compared with control subjects (0.62 ng/mL, P < .0001; 2.34 ng/mL, P < .0001). Serum S100B (0.09 ng/mL) was higher in patients with stroke compared with control subjects (0.01 ng/mL). CSF S100B levels were higher in patients with a cardioembolic stroke (2.88 ng/mL) than in those with small-vessel disease (0.89 ng/mL, P < .05). CSF S100B levels correlated with the National Institutes of Health Stroke Scale score on admission (R = 0.56, P < .01) and the stroke volume (R = 0.44, P = .01). CSF S100B and NfH-SMI35 levels correlated with outcome on the modified Rankin scale. CSF S100B levels were related to stroke severity and infarct volume and highest in cardioembolic stroke.

Marqueurs diagnostiques de la carence en fer: lequel choisir [Diagnostic markers of iron deficiency: which should we choose?].

Iron deficiency is generally investigated when faced with anemia, or with symptoms that could be related to iron deficiency without anemia. This simple disorder is easy to treat, provided that the diagnosis is correct. Several biological tests are available, but their interpretation is oftentimes problematic. Pre-analytical factors can interfere with measurements, normal values can change depending on suppliers, and, above all, results from different markers can be contradictory in some clinical situations. The aim of this article is to evaluate how the evolution of scientific knowledge and clinical trials can contribute to a better understanding and greater reliability in the diagnosis of iron deficiency.

Insights into the effects on metal binding of the systematic substitution of five key glutamate ligands in the ferritin of Escherichia coli

Ferritins are nearly ubiquitous iron storage proteins playing a fundamental role in iron metabolism. They are composed of 24 subunits forming a spherical protein shell encompassing a central iron storage cavity. The iron storage mechanism involves the initial binding and subsequent O-2-dependent oxidation of two Fe2+ ions located at sites A and B within the highly conserved dinuclear "ferroxidase center" in individual subunits. Unlike animal ferritins and the heme-containing bacterioferritins, the Escherichia coli ferritin possesses an additional iron-binding site (site C) located on the inner surface of the protein shell close to the ferroxidase center. We report the structures of five E. coli ferritin variants and their Fe3+ and Zn2+ (a redox-stable alternative for Fe2+) derivatives. Single carboxyl ligand replacements in sites A, B, and C gave unique effects on metal binding, which explain the observed changes in Fe2+ oxidation rates. Binding of Fe2+ at both A and B sites is clearly essential for rapid Fe2+ oxidation, and the linking of Fe-B(2+) to Fe-C(2+) enables the oxidation of three Fe2+ ions. The transient binding of Fe2+ at one of three newly observed Zn2+ sites may allow the oxidation of four Fe2+ by one dioxygen molecule.