The effects of folate and iron deficiency followed by supplementation on blood morphology and inflammation biomarkers in rats

BACKGROUND

Little is known about the relation between iron and folic acid (FA) supplementation and inflammation. The aim of this study was to evaluate the effects of iron and folate deficiency and supplementation on blood morphology parameters, and to assess the role of iron and folate transporters in inflammation.

METHODS

A four-week period of FA and iron deficiency in Wistar rats was followed by randomization into a group fed with a diet deficient in FA and supplemented with Fe (DFE), a group fed a diet deficient in Fe and supplemented with FA (DFOL), a group fed a diet supplemented with Fe and FA (FEFOL), a group fed a diet deficient in Fe and FA (D), and a group fed a control diet (C). The blood Crp concentration and blood count were determined. The expression of SLC11A2, SLC46A1, SLC19A1, and TFR2 proteins was assessed using the western blot method.

RESULTS

After ten days on the experimental diets, the rats in the DFOL group had a 21% higher concentration of white blood cells (WBC) than the FEFOL group did (p < 0.05). We did not observe any differences between the groups in terms of C-reactive protein (Crp) concentration. We also did not find any other differences between the groups in other morphological parameters. Analysis of the correlation between blood count parameters and the expression of iron and folate transporters gave conflicting results.

CONCLUSIONS

To conclude, iron and folate supplementation may affect WBC concentration in the blood.

SNPs rs11240569, rs708727, and rs823156 in SLC41A1 Do Not Discriminate Between Slovak Patients with Idiopathic Parkinson's Disease and Healthy Controls: Statistics and Machine-Learning Evidence

Gene SLC41A1 (A1) is localized within Parkinson’s disease-(PD)-susceptibility locus PARK16 and encodes for the Na⁺/Mg²⁺-exchanger. The association of several A1 SNPs with PD has been studied. Two, rs11240569 and rs823156, have been associated with reduced PD-susceptibility primarily in Asian populations. Here, we examined the association of rs11240569, rs708727, and rs823156 with PD in the Slovak population and their power to discriminate between PD patients and healthy controls. The study included 150 PD patients and 120 controls. Genotyping was performed with the TaqMan^® approach. Data were analyzed by conventional statistics and Random Forest machine-learning (ML) algorithm. Individually, none of the three SNPs is associated with an altered risk for PD-onset in Slovaks. However, a combination of genotypes of SNP-triplet GG_(rs11240569)/AG_(rs708727)/AA_(rs823156) is significantly (p < 0.05) more frequent in the PD (13.3%) than in the control (5%) cohort. ML identified the power of the tested SNPs in isolation or of their singlets (joined), duplets and triplets to discriminate between PD-patients and healthy controls as zero. Our data further substantiate differences between diverse populations regarding the association of A1 polymorphisms with PD-susceptibility. Lack of power of the tested SNPs to discriminate between PD and healthy cases render their clinical/diagnostic relevance in the Slovak population negligible.

The role of hepcidin, GDF15, and mitoferrin-1 in iron metabolism of polycythemia vera and essential thrombocytosis patients

Background/aim

GDF15, hepcidin and mitoferrin-1 (mfrn-1) are proteins involved in systemic iron regulation. There are no studies in the literature demonstrating the serum mfrn-1 levels in polycythemia vera (PV) and essential thrombocythemia (ET) patients. The aim of this study was to investigate GDF15, hepcidin and mfrn-1 levels in PV and ET patients.

Materials and methods

Ten PV, 17 ET patients, and 27 healthy controls (HCs) were enrolled. GDF15, hepcidin and mfrn-1 values were measured with enzyme-linked immunosorbent assay (ELISA).

Results

GDF15 levels were higher in the myeloproliferative neoplasm (MPN) group (P = 0.002). Hepcidin levels were not different between MPN patients and HCs. The mfrn-1 levels were lower in MPN patients (P = 0.039). Hepcidin, GDF15, and mfrn-1 levels were not different between PV and ET patients. mfrn-1 levels were lower in ET patients than HCs (P = 0.038).

Conclusion

Increased erythropoiesis in MPNs may lead to high GDF15 levels in these patients. However, hepcidin was not suppressed despite the increased GDF15 levels and erythropoiesis in these patients. Decrease in mfrn-1 in MPNs can be the result of its increased turnover due to increased myelopoiesis. It can be hypothesized that similar hepcidin levels in patients and controls and low mfrn-1 levels in patients may be a defense mechanism against erythroid activity and thromboembolic complications.

A moderate increase in dietary zinc reduces DNA strand breaks in leukocytes and alters plasma proteins without changing plasma zinc concentrations

BACKGROUND

Food fortification has been recommended to improve a population's micronutrient status. Biofortification techniques modestly elevate the zinc content of cereals, but few studies have reported a positive impact on functional indicators of zinc status.

OBJECTIVE

We determined the impact of a modest increase in dietary zinc that was similar to that provided by biofortification programs on whole-body and cellular indicators of zinc status.

DESIGN

Eighteen men participated in a 6-wk controlled consumption study of a low-zinc, rice-based diet. The diet contained 6 mg Zn/d for 2 wk and was followed by 10 mg Zn/d for 4 wk. To reduce zinc absorption, phytate was added to the diet during the initial period. Indicators of zinc homeostasis, including total absorbed zinc (TAZ), the exchangeable zinc pool (EZP), plasma and cellular zinc concentrations, zinc transporter gene expression, and other metabolic indicators (i.e., DNA damage, inflammation, and oxidative stress), were measured before and after each dietary-zinc period.

RESULTS

TAZ increased with increased dietary zinc, but plasma zinc concentrations and EZP size were unchanged. Erythrocyte and leukocyte zinc concentrations and zinc transporter expressions were not altered. However, leukocyte DNA strand breaks decreased with increased dietary zinc, and the level of proteins involved in DNA repair and antioxidant and immune functions were restored after the dietary-zinc increase.

CONCLUSIONS

A moderate 4-mg/d increase in dietary zinc, similar to that which would be expected from zinc-biofortified crops, improves zinc absorption but does not alter plasma zinc. The repair of DNA strand breaks improves, as do serum protein concentrations that are associated with the DNA repair process. This trial was registered at clinicaltrials.gov as NCT02861352.

Regulation of the Iron Homeostatic Hormone Hepcidin

Iron is required for many biological processes but is also toxic in excess; thus, body iron balance is maintained through sophisticated regulatory mechanisms. The lack of a regulated iron excretory mechanism means that body iron balance is controlled at the level of absorption from the diet. Iron absorption is regulated by the hepatic peptide hormone hepcidin. Hepcidin also controls iron release from cells that recycle or store iron, thus regulating plasma iron concentrations. Hepcidin exerts its effects through its receptor, the cellular iron exporter ferroportin. Important regulators of hepcidin, and therefore of systemic iron homeostasis, include plasma iron concentrations, body iron stores, infection and inflammation, and erythropoiesis. Disturbances in the regulation of hepcidin contribute to the pathogenesis of many iron disorders: hepcidin deficiency causes iron overload in hereditary hemochromatosis and nontransfused β-thalassemia, whereas overproduction of hepcidin is associated with iron-restricted anemias seen in patients with chronic kidney disease, chronic inflammatory diseases, some cancers, and inherited iron-refractory iron deficiency anemia. This review summarizes our current understanding of the molecular mechanisms and signaling pathways involved in the control of hepcidin synthesis in the liver, a principal determinant of plasma hepcidin concentrations.

Effect of testosterone on hepcidin, ferroportin, ferritin and iron binding capacity in patients with hypogonadotropic hypogonadism and type 2 diabetes

CONTEXT

As the syndrome of hypogonadotropic hypogonadism (HH) is associated with anaemia and the administration of testosterone restores haematocrit to normal, we investigated the potential underlying mechanisms.

DESIGN

Randomized, double-blind, placebo-controlled trial.

METHODS

We measured basal serum concentrations of erythropoietin, iron, iron binding capacity, transferrin (saturated and unsaturated), ferritin and hepcidin and the expression of ferroportin and transferrin receptor (TR) in peripheral blood mononuclear cells (MNC) of 94 men with type 2 diabetes. Forty-four men had HH (defined as subnormal free testosterone along with low or normal LH concentrations) while 50 were eugonadal. Men with HH were randomized to testosterone or placebo treatment every 2 weeks for 15 weeks. Blood samples were collected at baseline, 3 and 15 weeks after starting treatment. Twenty men in testosterone group and 14 men in placebo group completed the study.

RESULTS

Haematocrit levels were lower in men with HH (41·1 ± 3·9% vs 43·8 ± 3·4%, P = 0·001). There were no differences in plasma concentrations of hepcidin, ferritin, erythropoietin, transferrin or iron, or in the expression of ferroportin or TR in MNC among HH and eugonadal men. Haematocrit increased to 45·3 ± 4·5%, hepcidin decreased by 28 ± 7% and erythropoietin increased by 21 ± 7% after testosterone therapy (P < 0·05). There was no significant change in ferritin concentrations, but transferrin concentration increased while transferrin saturation and iron concentrations decreased (P < 0·05). Ferroportin and TR mRNA expression in MNC increased by 70 ± 13% and 43 ± 10%, respectively (P < 0·01), after testosterone therapy.

CONCLUSIONS

The increase in haematocrit following testosterone therapy is associated with an increase in erythropoietin, the suppression of hepcidin, and an increase in the expression of ferroportin and TR.

Characterization of zinc transporter 8 (ZnT8) antibodies in autoimmune diabetic patients from Argentinian population using monomeric, homodimeric, and heterodimeric ZnT8 antigen variants

OBJECTIVE

In order to gain further knowledge of the structure of zinc transporter 8 (ZnT8) epitopes, we studied the role of the amino acid at position 325 in the antigen and its dimeric conformation for autoantibodies to ZnT8 (ZnT8A) recognition.

METHODS

For this purpose, several ZnT8 C-terminal domain variants were designed: monomer carrying Arg325 or Trp325, homo-dimers ZnT8-Arg-Arg325 and ZnT8-Trp-Trp325, and hetero-dimer ZnT8-Arg-Trp325. Two groups of Argentinian diabetic patients were subjected to analysis using [(35)S]-ZnT8 variants by radioligand binding assay (RBA): i) 100 new-onset, insulin-dependent, type 1 diabetic patients and ii) 282 slowly progressing to insulin requirement, non-obese adult-onset diabetic patients. In addition, 50 type 1 diabetic patients and 100 normal control sera provided by the American Diabetes Association (ADA) were evaluated in order to calculate the sensitivity and specificity of ZnT8A assays for each antigenic variant. Other routine β-cell autoantibodies were also tested by RBA.

RESULTS

Of the 100 Argentinian type 1 diabetic patients, 65 were ZnT8A+. Out of them, 8 patients recognized all recombinant forms of ZnT8 and most patients (56) reacted against the heterodimer. Additionally, out of 282 non-obese adult-onset diabetic patients 46 were ZnT8A+, whereas 29 patients recognized only dimers. Besides, exclusive reactivity against ZnT8A was found in 9.0% for type 1 diabetes mellitus and 10.3% for non-obese adult-onset diabetic patients.

CONCLUSIONS

Significantly higher signal values in RBA were obtained with the heterodimeric variant. An increased detection of humoral autoimmunity was found in both groups when ZnT8A was employed in combination with the other β-cell autoantibodies. The inclusion of homodimeric immunoreactive peptides revealed the existence of quaternary structure-defined epitopes probably resembling the actual state of the autoantigen in vivo. Finally, the differential profiles of ZnT8A exhibited by type 1 and non-obese adult-onset diabetic patients suggest the different nature of autoimmune processes underlying both pathologies.

Clinical presentations of Wilson disease among Polish children

INTRODUCTION

Wilson disease (WD) may present from early childhood up to the eighth decade, presenting with variable hepatic and neuropsychiatric symptoms. Establishing the diagnosis is straightforward if the major clinical and laboratory features are present. However, clinical phenotypes are highly varied and early, proper diagnosis can be challenging.

AIM

The aim of our study was to analyze clinical presentations and diagnostic tests of Polish pediatric patients with WD.

METHODS

We retrospectively analyzed medical history of 156 patients with confirmed diagnosis of WD treated at our Institute from 1996 till March 2016.

RESULTS

The mean age at onset of symptoms was 10.15±4.23 years of age. Hepatic presentation was the most common one (94.23%) with either liver failure (16.03%) or more frequently increased transaminases (78.2%). In 90.26% cases ceruloplasmin serum concentration was ≤0,2 g/l, in 51.93% patients basal urinary copper excretion was >100 μg/24 h. Mutation analysis was performed in 155 (99.36%) cases. The most common mutation was p.H1069Q.

CONCLUSIONS

Wilson disease can present with only significantly increased transaminases activity and hepatomegaly or liver failure, but neurological symptoms are very rare in children. Diagnostic approach is challenging due to wide spectrum of clinical presentations in a high variable degree of severity. Genetic screening is supportive, ceruloplasmin and urinary copper excretion are valuable tests in the majority of patients but do not allow to exclude WD.

[THE DIFFERENTIAL DIAGNOSTIC OF ANEMIA]

The article presents analysis of the publications' data of the recent years concerning regulation of iron metabolism and possibilities of application of indicators of iron metabolism in differential diagnostic of anemia. The original results of protein detection are described concerning bivalent transporter of metals and ferroportine under iron-deficiency anemia, anemia of chronic inflammatory diseases and autoimmune hemolytic anemia. The significance of these proteins in more profound comprehension of pathogenesis is demonstrated

Biomarkers related to severe hypoglycaemia and lack of good glycaemic control in ACCORD

AIMS/HYPOTHESIS

In patients with diabetes, intensive glycaemic control reduces microvascular complications. However, severe hypoglycaemia frequently complicates intensive glycaemic control. Blood biomarkers that predict successful intensification of glycaemic control in patients with type 2 diabetes without the development of severe hypoglycaemia would advance patient care. In patients who received intensive treatment for type 2 diabetes from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, we hypothesised that insulin deficiency and islet autoantibodies would be associated with severe hypoglycaemia and failure to achieve near-normal glycaemia (HbA1c <6.0% [42 mmol/mol]).

METHODS

A nested case-control design was used. Cases (n = 326) were defined as participants having severe hypoglycaemia and failure to achieve an HbA1c level of <6.0% (42 mmol/mol) prior to the ACCORD transition or death. Controls (n = 1,075) were those who achieved an HbA1c level of <6.0% (42 mmol/mol) prior to the ACCORD transition or death without severe hypoglycaemia. Each case was matched (for race, age and BMI) by up to four controls. Baseline insulin deficiency (fasting C-peptide ≤0.15 nmol/l) and islet autoantibodies (glutamic acid decarboxylase [GAD], tyrosine phosphatase-related islet antigen 2 [IA2], insulin [IAA] and zinc transporter 8 [ZnT8]) were measured. Conditional logistic regression with and without adjustment for age, BMI and diabetes duration was used on the full cohort and after removal of patients who died and their respective controls.

RESULTS

Severe hypoglycaemia accompanied by an inability to achieve an HbA1c level of <6.0% (42 mmol/mol) was associated with insulin deficiency (adjusted OR 23.2 [95% CI 9.0, 59.5], p < 0.0001), the presence of IAA autoantibodies or baseline insulin use (adjusted OR 3.8 [95% CI 2.7, 5.3], p < 0.0001), GAD autoantibodies (OR 3.9 [95% CI 2.5, 6.0], p < 0.0001), IA2 autoantibodies (OR 16.7 [95% CI 3.9, 71.6], p = 0.0001) and ZnT8 autoantibodies (adjusted OR 3.9 [95% CI 1.2, 12.4], p = 0.02).

CONCLUSIONS

C-peptide and islet autoantibodies may serve as biomarkers to predict the risk of severe hypoglycaemia during intensification of type 2 diabetes treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00000620 (original ACCORD study).

Differential expression of genes related to mitochondrial biogenesis and bioenergetics in fatigued prostate cancer men receiving external beam radiation therapy

OBJECTIVES

This prospective study explored relationships between expression changes of genes related to mitochondrial biogenesis/bioenergetics and fatigue in men with prostate cancer receiving external beam radiation therapy (EBRT).

METHODS

Fatigue and gene expression were measured before (Day 0), at midpoint (Days 19-21), and at completion (Days 38-42) of EBRT using the seven-item Patient-Reported Outcomes Measurement Information System-Fatigue short form and from whole blood cell RNA, respectively. The human mitochondria RT2 Profiler PCR Array System was used to identify differential expression of mitochondrial biogenesis/bioenergetics-related genes. Mixed linear modeling estimated the changes in fatigue and gene expression over time and determined significant associations between gene expression and fatigue.

RESULTS

Subjects were 50 men with prostate cancer (scheduled for EBRT = 25, active surveillance as matched controls = 25). The mean Patient-Reported Outcomes Measurement Information System-Fatigue T-score (mean = 50 ± 10 in a general population) for study subjects was 44.87 ± 5.89 and for controls was 43.5 ± 2.8 at baseline. Differential expression of two genes inside the mitochondria involved in critical mitochondrial complexes: BCS1L (β = 1.30), SLC25A37 (β = -2.44), and two genes on the outer mitochondrial membrane vital for mitochondrial integrity: BCL2L1 (β = -1.68) and FIS1 (β = -2.35) were significantly associated with changes in fatigue scores of study subjects during EBRT.

CONCLUSION

Genes related to oxidative phosphorylation, energy production, and mitochondrial membrane integrity are associated with worsening fatigue during EBRT. Further investigation of the pathways involved with this association may explain mechanisms behind the development of fatigue in this population.

Ferroportin Q248H mutation, hyperferritinemia and atypical type 2 diabetes mellitus in South Kivu

BACKGROUND

The ferroportin Q248H mutation is relatively common in sub-Saharan Africa. No previous study examined its relationship with atypical diabetes mellitus (DM) in this area.

OBJECTIVE

To determine the potential interactions between ferroportin Q248H mutation, hyperferritinemia and DM in South Kivu (RDC).

METHODOLOGY

Presence of ferroportin Q248H mutation and iron status were investigated in diabetic patients (n=179, age (mean) 57.7 years, CRP (median) 0.16 mg/L) and non-diabetic subjects (n=86, age 44.5 years, CRP 0.07 mg/L) living in the city of Bukavu. Hyperferritinemia was considered for values greater than 200 and 300 μg/L in women and in men, respectively.

RESULTS

The prevalence of ferroportin Q248H mutation [12.1%] was non-significantly higher in diabetics than non-diabetics [14.0% vs. 8.1%, p=0.17]. Similarly, hyperferritinemia frequency was higher in diabetic patients with Q248H mutation [44.0% vs. 14.3%, p=0.16] and in mutation carriers [37.0% vs 16.5%, p=0.001] than in the control groups, respectively. The association between Q248H mutation and DM was nevertheless not significant [adjusted OR 1.70 (95% CI: 0.52-5.58), p=0.37], whereas hyperferritinemia [OR 2.72 (1.24-5.98), p=0.01] showed an independent effect after adjustment for age and metabolic syndrome.

CONCLUSIONS

The present work suggests a potential association between abnormal iron metabolism, ferroportin Q248H mutation and atypical DM in Africans, which may be modulated by environmental factors.

Prevalence of zinc transporter 8 antibodies in gestational diabetes mellitus

AIMS

Gestational diabetes mellitus affects approximately 7% of all pregnant women. Some of these women develop autoantibodies that are generally characteristic of Type 1 diabetes. Autoantibodies targeting glutamic acid decarboxylase and tyrosine phosphatase-like protein are the most frequently reported. A recently identified autoantigen in Type 1 diabetes is zinc transporter 8. Some reports suggest that the frequency of zinc transporter 8 antibodies is as high as glutamic acid decarboxylase antibodies in Type 1 diabetes and thus a good diagnostic marker for autoimmune diabetes. There are currently no reports of zinc transporter 8 antibodies in gestational diabetes. The aim of this pilot study was to investigate the frequency of zinc transporter 8 antibodies in patients at clinical onset of gestational diabetes mellitus.

METHODS

  Subjects included in this pilot study were all diagnosed with gestational diabetes at Skåne University Hospital, Lund, Sweden, 2009-2010 (n = 193). Sera samples were analysed for antibodies using a commercial enzyme-linked immunosorbent assay according to the manufacturers' instructions.

RESULTS

We found that 19/193 patients with gestational diabetes, diagnosed in 2009-2010, were positive for at least one autoantibody. Glutamic acid decarboxylase was the most common single autoantibody (52.6%; 10/19), followed by zinc transporter 8 (21.1%; 4/19) and tyrosine phosphatase-like protein (15.8%; 3/19). Combinations of two or more antibodies were rare (10.5%; 2/19).

CONCLUSIONS

In this study, we found that zinc transporter 8 added 2.1% (4/193) of autoantibody positivity in women with gestational diabetes who were negative for glutamic acid decarboxylase and tyrosine phosphatase-like protein antibodies. Glutamic acid decarboxylase was still the most prevalent autoantibody in gestational diabetes, but, as zinc transporter 8 was present even in the absence of glutamic acid decarboxylase, this autoantibody could be an important independent marker of autoimmunity in gestational diabetes.

Zinc transporter-8 autoantibodies improve prediction of type 1 diabetes in relatives positive for the standard biochemical autoantibodies

OBJECTIVE

We assessed diabetes risk associated with zinc transporter-8 antibodies (ZnT8A), islet cell antibodies (ICA), and HLA type and age in relatives of people with type 1 diabetes with the standard biochemical autoantibodies (BAA) to insulin (IAA), GAD65 (GAD65A), and/or insulinoma-associated protein 2 antigen (IA-2A).

RESEARCH DESIGN AND METHODS

For this analysis, 2,256 relatives positive for at least one BAA, of whom 142 developed diabetes, were tested for ZnT8A, ICA, and HLA genotype followed by biannual oral glucose tolerance tests. ZnT8A were also tested in 911 randomly chosen antibody-negative relatives.

RESULTS

ZnT8A were associated with the other BAA (548 of 2,256 [24.3%] BAA(+) vs. 8 of 911 [0.8%] BAA(-), P < 0.001) and BAA number (177 of 1,683 [10.5%] single-, 221 of 384 [57.6%] double-, and 150 of 189 [79.4%] triple-BAA positivity, P < 0.001). The 4-year diabetes risk was higher in single BAA(+) relatives with ZnT8A than ZnT8A(-) relatives (31 vs. 7%, P < 0.001). In multivariable analysis, age ≤ 20 years (hazard ratio 2.13, P = 0.03), IA-2A (2.15, P = 0.005), IAA (1.73, P = 0.01), ICA (2.37, P = 0.002), and ZnT8A (1.87, P = 0.03) independently predicted diabetes, whereas HLA type (high and moderate vs. low risk) and GAD65A did not (P = 0.81 and 0.86, respectively).

CONCLUSIONS

In relatives with one standard BAA, ZnT8A identified a subset at higher diabetes risk. ZnT8A predicted diabetes independently of ICA, the standard BAA, age, and HLA type. ZnT8A should be included in type 1 diabetes prediction and prevention studies.

Expression of the zinc transporters genes and metallothionein in obese women

Research has investigated the participation of zinc transport proteins and metallothionein in the metabolism of this mineral. However, studies about the genetic expression of these proteins in obese patients are scarce. The study determined the expression of zinc transporter protein codifying genes (ZnT-1, Zip-1 and Zip-3) and of metallothionein in 55 obese women, aged between 20 and 56 years. The assessment of body composition was carried out using anthropometric measurements and bioelectrical impedance. Zinc intake was obtained by recording diet over a 3-day period, and the nutritional analysis was carried out using NutWin software version 1.5. The plasmatic and erythrocytary zinc were analyzed by atomic absorption spectrophotometry (λ=213. 9 nm). The determination of mRNA expression of the zinc transporter proteins and metallothionein was carried out using blood, using the RT-PCR method. The mean values of body mass index were 37.9±5.5 kg/m2. The average intake of zinc was 9.4±2.3 mg/day. The analysis of the zinc plasma concentrations showed values of 58.4±10.9 μg/dL. The mean values of zinc in the erythroytes were 38.7±9.1 μg/g Hb. The metallothionein gene had a higher expression in the blood, when compared to zinc transporters ZnT-1, Zip-1, and Zip-3 (p=0.01). The study shows that there are alterations in the biochemical parameters of zinc in obese patients assessed, as well as higher expression of the codifying gene metallothionein, when compared to the investigated zinc transporters.

Analysis of pathogenesis of juvenile new-onset diabetes

BACKGROUND

Measurement of anti-islet autoantibodies at the time of disease onset contributes greatly to the differentiation of Type 1A diabetes with HLA Class II subtyping also contributing.

METHODS

Blood samples were obtained from 900 patients with age from 1 month to 25 years (median age 11.1 years) within 2 weeks of diabetes onset to test anti-islet autoantibodies to insulin (IAA), glutamic acid decarboxylase (GADA), insulinoma antigen (IA-2AA), the zinc transporter-8 (ZnT8AA), and islet-cell antibodies (ICA). Polymorphisms of the HLA Class II gene were typed in 547 randomly selected patients.

RESULTS

Of the 900 subjects analyzed, 145 (16.1%) were negative for all five anti-islet autoantibodies, and autoantibody negativity significantly increased with age: 10.2% (38/372) among children <10 years of age, 14.2% (46/325) in those 10-14 years of age, and 30.1% (61/203) in those >14 years of age (P < 0.001). The prevalence of IA-2AA was the highest among young children. The prevalence of GADA increased with age while the prevalence of IAA was inversely correlated with age. At diagnosis, the subjects with negative antibodies had a higher body mass index (P < 0.001) and less high risk HLA genotype DR3-DQ2/DR4-DQ8 (P < 0.01).

CONCLUSION

A large percentage of children and youths negative for all anti-islet autoantibodies at the onset of diabetes are likely to have the non-immune form, especially those without DR3/DR4 and obese patients. Among autoantibody-positive Type 1A patients, IAA and GADA showed a reciprocal prevalence, suggesting differential disease pathogenesis.

Fulminant type 1 diabetes mellitus exhibits distinct clinical and autoimmunity features from classical type 1 diabetes mellitus in Chinese

BACKGROUND

fulminant type 1 diabetes mellitus (T1DM) is characterized by abrupt onset of hyperglycemia and rapid progression to ketoacidosis. This study aimed at examining the clinical and autoimmunity features of fulminant T1DM in Chinese.

METHODS

a total of 24 patients with fulminant T1DM and 48 classical autoimmune T1DM patients with acute onset of ketoacidosis were recruited. Anthropometric and biochemical parameters were tested. Serum antibodies against glutamic acid decarboxylase 65, tyrosine phosphatase-2 and zinc transporter 8 were measured, and human leukocyte antigen-DQ haplotypes were determined. Peripheral glutamic acid decarboxylase 65-specific T-cell responses in some subjects were determined.

RESULTS

compared with autoimmune T1DM patients, patients with fulminant T1DM displayed more flu-like and gastrointestinal symptoms, and had significantly higher concentrations of plasma glucose, more severe ketoacidosis, very low levels of pancreatic β-cell reserve, but only slightly increased haemoglobin A(1c) levels. In some patients, the disease onset was associated with drug-related hypersensitivity, pregnancy, or positive serum IgM against viruses. Forty percent (8/20) had low titres of autoantibodies against at least one of the islet autoantigens tested. Three out of six patients had positive glutamic acid decarboxylase-reactive Th1 responses. The frequency of human leukocyte antigen -DQA1*0102-DQB1*0601 haplotype was significantly higher in patients with fulminant T1DM.

CONCLUSIONS

fulminant T1DM is a distinct entity with unique clinical characteristics and may be mediated by multiple factors, including viral infection, pregnancy, and drug sensitivity syndrome, among others, in the presence of humoral and/or cellular autoimmunity and susceptible genetic background.

Collecting high-quality pancreatic tissue for experimental study from organ donors with signs of β-cell autoimmunity

BACKGROUND

The aim of this study was to create a new research strategy to obtain high-quality pancreatic tissues from subjects with preclinical or clinical type 1 diabetes, which would open up new avenues for studying the mechanisms of the β-cell damaging process in humans.

RESEARCH DESIGN AND METHODS

A nationwide collaboration network (the PanFin network) was established in Finland to start an on-call screening of diabetes-associated autoantibodies from deceased organ donors and subsequent processing of pancreases from autoantibody-positive donors. This protocol was integrated into the national organ transplantation procedure.

RESULTS

Only a few modifications were needed to the normal transplantation practices. One additional blood sample was obtained from donors for autoantibody analyses, the transplantation team was informed about the autoantibody result and the pancreas of autoantibody-positive donors was transported to the core laboratory. Altogether, 307 donors were screened and 22 (7.2%) were positive for at least one autoantibody and 3 tested positive for two or more autoantibodies out of the five tested (islet cell antibodies, insulin autoantibodies and autoantibodies to glutamic acid decarboxylase, islet antigen 2 and zinc transporter 8). The quality of collected pancreatic tissue was superior to that from autopsies and allowed the detection of both RNA and proteins.

CONCLUSIONS

The study protocol was proven feasible to be carried out on a nationwide scale. It did not interfere with the normal transplantation activities and provided valuable tissue material for research.

Association of ATP7B mutation detection rate with biochemical characteristics in Korean patients with Wilson disease

Wilson disease (WD) is an autosomal recessive disorder caused by mutations in the ATP7B gene, yet many patients have either one mutation, or no mutation. We investigated whether the mutation detection rate is associated with any biochemical characteristics of WD. In a study of 71 patients, we used PCR-sequencing to screen for ATP7B mutations in 7 exons (exons 8, 10, 11, 14, 15, 16, and 18) covering 95% of known mutations in Korean patients with WD. We also investigated serum concentrations of various biochemical analytes. Data were analyzed by linear association test and one-way ANOVA. Based on the number of detected ATP7B mutations, a significant difference in serum ceruloplasmin concentration was found among the 3 groups (p <0.001). Serum ceruloplasmin concentration averaged 3.32 +/- 1.74, 10.8 +/- 5.50, and 14.9 +/- 3.88 mg/dl (mean +/- SD) in the 25, 20, and 26 patients with two, one, and no ATP7B mutations, respectively. We observed 82.9% and 16.7% of mutant allele frequency in WD patients with ceruloplasmin concentration <10 mg/dl and 10-20 mg/dl, respectively (p <0.001). Thus serum ceruloplasmin concentrations among WD patients differed according to the number of ATP7B mutations detected.

[Effect of allergy on outcomes after endoscopic sinus surgery in patients with chronic rhinosinusitis]

OBJECTIVE

To explore correlation of allergy and outcomes after endoscopic sinus surgery (ESS) in patients with chronic rhinosinusitis.

METHOD

Before ESS, 115 cases were arranged to detect allergic serum relative index: the concentration of serum TIgE, specific IgE semi-quantitative test and the concentration of serum ECP; to survey QOL status: VAS, SNOT-20 and SF-36; as well as inquire medical record, Lund-Mackay CT system scoring, clinical classification of chronic rhinosinusitis. After ESS (>1 year), 74 cases were followed up. The subjective and objective assessment were achieved by means of VAS, SNOT-20, SF-36 and Lund-Kennedy endoscopic scores.

RESULT

The improvements of VAS scores of the cases with increased serum TIgE were significantly lower than those without increased serum TIgE (P<0.05). In cases of II, III types, the objective outcomes of the cases with increased serum TIgE were significantly worse than those without increased serum TIgE (P<0.05). The objective outcomes of the cases with positive allergen (> or = 3) were significantly worse than those with positive allergen (<3) (P<0.05). The objective outcomes of the cases with strong positive allergen were significantly worse than those without strong positive allergen (P<0.05). VAS scores and SNOT-20 scores after endoscopic sinus surgery of the cases with strong positive allergen were significantly worse than those without strong positive allergen (P<0.05). The concentration of serum ECP of the invalid cases was significantly higher than effective cases (P<0.05). The concentration of serum ECP was positive correlated with Lund-Kennedy endoscopic scores (r=0.49, P<0.05). In cases of II, III types, the objective outcomes of the cases with increased serum ECP were significantly worse than those without increased serum ECP (P<0.05), VAS scores and SNOT-20 scores after endoscopic sinus surgery of the cases with increased serum ECP were significantly worse than those without incre- ased serum ECP (P<0.05), the improvements of VAS scores of the cases with increased serum ECP were significantly lower than those without increased serum ECP (P<0.05).

CONCLUSION

Those allergic serum relative indexes make some negative effect on subjective and objective outcomes. Especially, in cases with polyps, the increase of serum TIgE and serum ECP has more negative effect. Our results might help to choose immunotherapy to combine with endoscopic sinus surgery for those selected patients to improve the outcomes of chronic rhinosinusitis.

Structure and expression of genes involved in transport and storage of iron in red-blooded and hemoglobin-less antarctic notothenioids

Antarctic notothenioids are characterized by a drastic reduction of the hemoglobin content, a condition that reaches its extreme in icefish that, following a gene deletion event, are completely devoid of hemoglobin. To answer the question on what type of adaptive changes occurred in icefish to prevent accumulation of potentially dangerous ferrous iron, we investigated the genes of four proteins known to play a key role in iron metabolism. For this purpose, we cloned and sequenced the cDNAs encoding ceruloplasmin, transferrin, ferritin and divalent metal transporter 1. While the inferred amino acid sequences of transferrin from different Antarctic fish species showed a high level of similarity with the homologous proteins from other species, ceruloplasmin sequence featured amino acid substitutions affecting a copper binding site. Another peculiarity was the presence in subunit H of the icefish ferritin of the two sets of sites involved in iron oxidation and iron mineralization, which in mammals are located on two distinct ferritin subunits. Significant differences in the expression levels of the four genes were found between hemoglobinless and red-blooded notothenioids. An increased expression of ceruloplasmin mRNA in icefish was interpreted as a compensatory mechanism to prevent accumulation of ferrous iron in hemoglobinless fish. In icefish, the amounts of ferritin H-chain mRNA measured in liver, blood and head kidney were lower than in the same organs of the red-blooded fish. In the spleen of both fishes, the expression levels of ferritin H-chain were significantly lower than in the spleen of a "pink-blooded" notothenioid with an intermediate hemoglobin content. Finally, the amount of divalent metal transporter mRNA measured in the head-kidney was lower in the icefish than in the same organ of its red-blooded counterpart. These results indicate that the loss of hemoglobin in icefish is accompanied by remodulation of the iron metabolism.

P2X7 and NRAMP1/SLC11 A1 gene polymorphisms in Mexican mestizo patients with pulmonary tuberculosis

Tuberculosis remains one of the most important infectious diseases worldwide. Several studies have suggested that genetic factors may affect susceptibility to tuberculosis, but the specific genes involved have not yet been fully characterized. NRAMP1/SLC11 A1 and P2X(7) genes have been linked to increased risk for tuberculosis in some African and Asiatic populations. To explore the potential role of these genes in the susceptibility to pulmonary tuberculosis in a Mexican mestizo population, we evaluated the association of D543N and 3'-UTR polymorphisms in NRAMP1/SLC11 A1 and - 762 and A1513C polymorphisms in P2X(7) genes with the risk for tuberculosis. Polymerase chain reaction (PCR) amplification of genomic DNA followed by restriction fragment length polymorphism analysis, and allelic-specific PCR was employed. We found no significant differences in allelic frequency in NRAMP1/SLC11 A1 gene polymorphisms in 94 patients with tuberculosis compared to 100 healthy contacts. Similarly, no significant association of the P2X(7)-762 gene polymorphism with tuberculosis was detected. In contrast, the P2X(7) A1513C polymorphism was associated significantly with tuberculosis (P = 0.02, odds ratio = 5.28, 95% CI, 0.99-37.69), an association that had not been reported previously. However, when the function of P2X(7) was assessed by an L-selectin loss assay, we did not find significant differences in patients compared to healthy contacts or between PPD(+) and PPD(-) control individuals. This study further supports the complex role of P2X(7) gene in host regulation of Mycobacterium tuberculosis infection, and demonstrates that different associations of gene polymorphisms and tuberculosis are found in distinct racial populations.

[Hereditary hemochromatosis]

Hereditary hemochromatosis is an inherited disorder of iron metabolism in the Caucasian population with an autosomal recessive inheritance and a prevalence between 1 in 200 and 1 in 500. Until the discovery of HFE gene the diagnosis of hemochromatosis required documentation of iron overload or family linkage using HLA testing. The discovery of HFE gene has established the foundation for a better understanding of iron homeostasis and has changed hemochromatosis management: liver biopsy, gold standard diagnostic, was replaced by genetic test and it was suggested that population screening using genetic testing might be ideal for HFE related hemochromatosis. Considered for long time a unitary disease, a monogenic disorder characterized by excess tissue deposits of iron and subsequently organ damage, hemochromatosis is in fact a polygenic disease with many faces. The Online Mendelian Inheritance in Man database has lists four types of hereditary hemochromatosis, each of them caused by a different gene mutation (hepcidine, hemojuvelin, transferring receptor 2, ferroportin). The basic features shared by iron overload disorders associated with mutation in HFE, hepcidine, hemojuvelin, transferring receptor 2, ferroportin gene indicate that they are genetic variation of the same syndrome. Hereditary hemochromatosis must be distinguished from the other syndrome of iron overload and the classic term hereditary hemochromatosis should be reserved only for HFE related hemochromatosis.

Identification of in vivo-expressed antigens of Staphylococcus aureus and their use in vaccinations for protection against nasal carriage

A spectrum of in vivo-expressed Staphylococcus aureus antigens was identified by probing bacteriophage expression libraries of S. aureus with serum samples from infected and uninfected individuals. Eleven recombinant antigenic proteins were produced, and specific antibody titers in a large collection of human serum samples were determined. Significantly increased concentrations of reactive immunoglobulin G (IgG) to 7 antigens were found in serum samples from ill individuals, compared with those in healthy individuals. Significantly higher concentrations of reactive IgG to 4 antigens, including iron-responsive surface determinant (Isd) A and IsdH, were found in serum samples from healthy individuals who were not nasal carriers of S. aureus, compared with those in healthy carriers. Vaccination of cotton rats with IsdA or IsdH protected against nasal carriage. Also, IsdA is involved in adherence of S. aureus to human desquamated nasal epithelial cells and is required for nasal colonization in the cotton rat model. Thus, vaccination with these antigens may prevent S. aureus carriage and reduce the prevalence of human disease.

Ferroportin (Q248H) mutations in African families with dietary iron overload

BACKGROUND

Dietary iron overload found in sub-Saharan Africa might be caused by an interaction between dietary iron and an iron-loading gene. Caucasian people with ferroportin gene mutations have iron overload histologically similar to that found in African patients with iron overload. Ferroportin is also implicated in the hypoferremic response to inflammation. The prevalence of the ferroportin Q248H mutation, unique to African people, and its association with dietary iron overload, mean cell volume (MCV) and C-reactive protein (CRP) were examined in 19 southern African families.

METHODS

Polymerase chain reaction (PCR) and restriction enzyme digestion were used to identify the Q248H mutation. Statistical analysis was carried out to correlate the presence of the mutation with markers of iron overload and inflammation.

RESULTS

We identified three (1.4%) Q248H homozygotes and 53 (24.1%) heterozygotes in the families examined in the present study. There was no increased prevalence of the mutation in index subjects or their families. Logistic regression showed significantly higher serum ferritin concentrations with the mutation. The mean cell volume (MCV) was significantly lower, and the serum CRP significantly higher in subjects who carried the mutation.

CONCLUSIONS

The present study of 19 families with African iron overload failed to show evidence that the ferroportin (Q248H) mutation is responsible for the condition. Logistic regression, correcting for factors influencing iron status, did show increased ferritin levels in individuals with the mutation. The strong association with low MCV suggests the possibility that the ferroportin (Q248H) mutation might interfere with iron supply, whereas the elevated serum CRP might indicate that the ferroportin mutation influences the inflammatory response in African populations.

Microcytic anemia and hepatic iron overload in a child with compound heterozygous mutations in DMT1 (SCL11A2)

Divalent metal transporter 1 (DMT1) mediates apical iron uptake in duodenal enterocytes and iron transfer from the transferrin receptor endosomal cycle into the cytosol in erythroid cells. Both mk mice and Belgrade rats, which carry an identical DMT1 mutation, exhibit severe microcytic anemia at birth and defective intestinal iron use and erythroid iron use. We report the hematologic phenotype of a child, compound heterozygote for 2 DMT1 mutations, who was affected by severe anemia since birth and showed hepatic iron overload. The novel mutations were a 3-bp deletion in intron 4 (c.310-3_5del CTT) resulting in a splicing abnormality and a C>T transition at nucleotide 1246(p. R416C). A striking reduction of DMT1 protein in peripheral blood mononuclear cells was demonstrated by Western blot analysis. The proband required blood transfusions until erythropoietin treatment allowed transfusion independence when hemoglobin levels between 75 and 95 g/L (7.5 and 9.5 g/dL) were achieved. Hematologic data of this patient at birth and in the first years of life strengthen the essential role of DMT1 in erythropoiesis. The early onset of iron overload indicates that, as in animal models, DMT1 is dispensable for liver iron uptake, whereas its deficiency in the gut is likely bypassed by the up-regulation of other pathways of iron use.

[Erythrophagocytosis and recycling of heme iron in normal and pathological conditions; regulation by hepcidin]

Most of the iron required for erythropoiesis is provided by heme iron recycling following degradation of senescent erythrocytes by tissue macrophages. Accumulation of biochemical modifications at the red blood cell membrane during ageing (externalisation of phosphatidyl-serine, peroxydation of membrane-bound lipoproteins, loss of sialic acid residues and formation of senescence neoantigens) constitute a series of signals that will allow the macrophage to identify the red blood cells to be eliminated, through interaction with specific receptors. After this initial recognition step, the red blood cell is internalised by phagocytosis, and phagosome maturation, which can comprise recruitment of the endoplasmic reticulum, will favour degradation of red blood cell constituents. Heme is catabolised by heme oxygenase 1, anchored in the endoplasmic reticulum membrane. A fraction of the released iron will be recycled back to the plasma through ferroportin, a membrane-bound Fe (II) export molecule, and a fraction will retained within the ferritin molecules, to be released at later stages. Multiple evidence coming from human diseases (type 4 hemochromatosis) and animal models indicate that ferroportin is essential for heme iron recycling by macrophages. Furthermore, ferroportin seems to be the molecular target of hepcidin, this circulating peptide synthesized by the liver and acting as a negative regulator of intestinal iron absorption and iron recycling by macrophages. Perturbations in erythrophagocytosis play a physiopathological role in several diseases, including hemochromatosis, anemia of chronic disorders and thalassemia.

Role of ferritin and ferroportin genes in unexplained hyperferritinaemia

A large body of evidence indicates that the level of serum ferritin parallels the concentration of storage iron within the body, regardless of the cell type in which it is stored. Elevated serum ferritin levels, in the absence of inflammation and liver disease, are currently taken to indicate increased iron stores and require further investigation to determine the site of iron overload. Until recently, the only genetic disorder with elevated serum ferritin levels known in Western countries was hereditary HLA-related HFE-related genetic haemochromatosis in Caucasians (HFE, OMIM 235200), and a high serum ferritin in apparently healthy persons was considered suggestive of this disease. In the last few years, at least two novel genetic disorders of iron metabolism presenting as unexplained hyperferritinaemia have been recognized. The first one is hereditary hyperferritinaemia/cataract syndrome (HHCS, OMIM 600886). HHCS arises from various point mutations or deletions within a protein binding sequence in the 5'-UTR of the L-ferritin mRNA that results in increased efficiency of L-ferritin translation. The second one is haemochromatosis type 4, or HFE4 (OMIM 606069), or ferroportin disease. In this latter condition, reticuloendothelial iron overload and hyperferritinaemia are caused by loss-of-function mutations in the SLC11A3 gene that mainly impair macrophage iron recycling. These genetic disorders should be taken into account in the differential diagnosis of unexplained hyperferritinaemia.

Hemochromatosis with mutation of the ferroportin 1 (IREG1) gene

The HFE, H ferritin, TFR2, and ferroportin 1 genes of a Japanese patient diagnosed as having hemochromatosis were amplified by PCR and sequenced. A novel mutation in the ferroportin 1 was found in the patient. It was located in the noncoding region of the ferroportin 1; nucleotide 117 adenine was changed to guanine, 7 nucleotides downstream the iron responsive element (IRE) region. This mutation was not found in the patient's son or daughter, or in 50 healthy individuals. It was suggested that the mutation in the ferroportin 1 may be related to hemochromatosis of this patient.

Reduced plasma membrane Ca2+-ATPase function in platelets from patients with non-insulin-dependent diabetes mellitus

We clearly show that plasma membrane Ca2+ ATPase (PMCA) activity is lower in platelets from patients with non-insulin-dependent diabetes mellitus (NIDDM) than in those from healthy controls. The lower activity is likely due to reduced PMCA expression and increased tyrosine phosphorylation. These findings provide an explanation for the cellular ionic defects occurring in insulin resistant conditions.

Cytokine-mediated regulation of iron transport in human monocytic cells

Under chronic inflammatory conditions cytokines induce a diversion of iron traffic, leading to hypoferremia and retention of the metal within the reticuloendothelial system. However, the regulatory pathways underlying these disturbances of iron homeostasis are poorly understood. We investigated transferrin receptor (TfR)-dependent and -independent iron transport mechanisms in cytokine-stimulated human monocytic cell lines THP-1 and U937. Combined treatment of cells with interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) reduced TfR mRNA levels, surface expression, and iron uptake, and these effects were reversed by interleukin-10 (IL-10), thus stimulating TfR-mediated iron acquisition. IFN-gamma and LPS dose-dependently increased the cellular expression of divalent metal transporter-1, a transmembrane transporter of ferrous iron, and stimulated the uptake of nontransferrin bound iron (NTBI) into cells. At the same time, IFN-gamma and LPS down-regulated the expression of ferroportin mRNA, a putative iron exporter, and decreased iron release from monocytes. Preincubation with IL-10 partly counteracted these effects. Our results demonstrate that the proinflammatory stimuli IFN-gamma and LPS increase the uptake of NTBI via stimulation of divalent metal transporter-1 expression and cause retention of the metal within monocytes by down-regulating ferroportin synthesis. Opposite, the anti-inflammatory cytokine IL-10 stimulates TfR-mediated iron uptake into activated monocytes. The regulation of iron transport by cytokines is a key mechanism in the pathogenesis of anemia of chronic disease and a promising target for therapeutic intervention.

Characterization of the iron transporter DMT1 (NRAMP2/DCT1) in red blood cells of normal and anemic mk/mk mice

Divalent metal transporter 1 (DMT1) is the major transferrin-independent iron uptake system at the apical pole of intestinal cells, but it may also transport iron across the membrane of acidified endosomes in peripheral tissues. Iron transport and expression of the 2 isoforms of DMT1 was studied in erythroid cells that consume large quantities of iron for biosynthesis of hemoglobin. In mk/mk mice that express a loss-of-function mutant variant of DMT1, reticulocytes have a decreased cellular iron uptake and iron incorporation into heme. Interestingly, iron release from transferrin inside the endosome is normal in mk/mk reticulocytes, suggesting a subsequent defect in Fe(++) transport across the endosomal membrane. Studies by immunoblotting using membrane fractions from peripheral blood or spleen from normal mice where reticulocytosis was induced by erythropoietin (EPO) or phenylhydrazine (PHZ) treatment suggest that DMT1 is coexpressed with transferrin receptor (TfR) in erythroid cells. Coexpression of DMT1 and TfR in reticulocytes was also detected by double immunofluorescence and confocal microscopy. Experiments with isoform-specific anti-DMT1 antiserum strongly suggest that it is the non-iron-response element containing isoform II of DMT1 that is predominantly expressed by the erythroid cells. As opposed to wild-type reticulocytes, mk/mk reticulocytes express little if any DMT1, despite robust expression of TfR, suggesting a possible effect of the mutation on stability and targeting of DMT1 isoform II in these cells. Together, these results provide further evidence that DMT1 plays a central role in iron acquisition via the transferrin cycle in erythroid cells.