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1.
PLoS One ; 16(12): e0261690, 2021.
Article in English | MEDLINE | ID: mdl-34932603

ABSTRACT

BACKGROUND: In hemochromatosis, causes of abdominal pain and its associations with cirrhosis are poorly understood. METHODS: We retrospectively compared characteristics of referred hemochromatosis probands with HFE p.C282Y homozygosity with/without biopsy-proven cirrhosis: sex, age, diabetes, heavy alcohol consumption, abdominal pain/tenderness, hepatomegaly, splenomegaly, non-alcoholic fatty liver disease, chronic viral hepatitis, ascites, transferrin saturation (TS), serum ferritin (SF), and iron removed by phlebotomy (QFe). We performed logistic regression on cirrhosis using characteristics identified in univariate comparisons. We performed computerized and manual searches to identify hemochromatosis case series and compiled prevalence data on cirrhosis and abdominal pain and causes of abdominal pain. RESULTS: Of 219 probands, 57.1% were men. Mean age was 48±13 y. In 22 probands with cirrhosis, proportions of men, mean age, prevalences of heavy alcohol consumption, abdominal pain, abdominal tenderness, hepatomegaly, splenomegaly, and chronic viral hepatitis, and median TS, SF, and QFe were significantly greater than in probands without cirrhosis. Regression analysis revealed three associations with cirrhosis: abdominal pain (p = 0.0292; odds ratio 9.8 (95% CI: 1.2, 76.9)); chronic viral hepatitis (p = 0.0153; 11.5 (95% CI: 1.6, 83.3)); and QFe (p = 0.0009; 1.2 (95% CI: 1.1, 1.3)). Of eight probands with abdominal pain, five had cirrhosis and four had diabetes. One proband each with abdominal pain had heavy alcohol consumption, chronic viral hepatitis B, hepatic sarcoidosis, hepatocellular carcinoma, and chronic cholecystitis, cholelithiasis, and sigmoid diverticulitis. Abdominal pain was alleviated after phlebotomy alone in four probands. In 12 previous reports (1935-2011), there was a negative correlation of cirrhosis prevalence and publication year (p = 0.0033). In 11 previous reports (1935-1996), a positive association of abdominal pain prevalence and publication year was not significant (p = 0.0802). CONCLUSIONS: Abdominal pain, chronic viral hepatitis, and QFe are significantly associated with cirrhosis in referred hemochromatosis probands with HFE p.C282Y homozygosity. Iron-related and non-iron-related factors contribute to the occurrence of abdominal pain.


Subject(s)
Abdominal Pain/etiology , Hemochromatosis Protein/genetics , Hemochromatosis/complications , Liver Cirrhosis/etiology , Female , Hemochromatosis/genetics , Homozygote , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide/genetics , Retrospective Studies
2.
Blood Cells Mol Dis ; 85: 102463, 2020 11.
Article in English | MEDLINE | ID: mdl-32652459

ABSTRACT

Glyceronephosphate O-acyltransferase (GNPAT) p.D519G (rs11558492) was identified as a genetic modifier correlated with more severe iron overload in hemochromatosis through whole-exome sequencing of HFE p.C282Y homozygotes with extreme iron phenotypes. We studied the prevalence of p.D519G in HFE p.C282Y/p.H63D compound heterozygotes, a genotype associated with iron overload in some patients. Cases were Australian participants with elevated serum ferritin (SF) levels ≥300µg/L (males) and ≥200µg/L (females); subjects whose SF levels were below these cut-offs were designated as controls. Samples were genotyped for GNPAT p.D519G. We compared the allele frequency of the present subjects, with/without elevated SF, to p.D519G frequency in public datasets. GNPAT p.D519G was more prevalent in our cohort of p.C282Y/p.H63D compound heterozygotes with elevated SF (37%) than European public datasets: 1000G 21%, gnomAD 20% and ESP 21%. We conclude that GNPAT p.D519G is associated with elevated SF in Australian HFE p.C282Y/p.H63D compound heterozygotes.


Subject(s)
Acyltransferases/genetics , Hemochromatosis Protein/genetics , Hemochromatosis/genetics , Point Mutation , Adult , Female , Ferritins/blood , Hemochromatosis/blood , Heterozygote , Humans , Male , Middle Aged
3.
PLoS One ; 15(4): e0232125, 2020.
Article in English | MEDLINE | ID: mdl-32324809

ABSTRACT

BACKGROUND: Few cross-sectional studies report iron deficiency (ID) prevalence in women of different race/ethnicity and ages in US or Canada. MATERIALS AND METHODS: We evaluated screening observations on women who participated between 2001-2003 in a cross-sectional, primary care-based sample of adults ages ≥25 y whose observations were complete: race/ethnicity; age; transferrin saturation; serum ferritin; and HFE p.C282Y and p.H63D alleles. We defined ID using a stringent criterion: combined transferrin saturation <10% and serum ferritin <33.7 pmol/L (<15 µg/L). We compared ID prevalence in women of different race/ethnicity subgrouped by age and determined associations of p.C282Y and p.H63D to ID overall, and to ID in women ages 25-44 y with or without self-reported pregnancy. RESULTS: These 62,685 women included 27,079 whites, 17,272 blacks, 8,566 Hispanics, 7,615 Asians, 449 Pacific Islanders, 441 Native Americans, and 1,263 participants of other race/ethnicity. Proportions of women with ID were higher in Hispanics and blacks than whites and Asians. Prevalence of ID was significantly greater in women ages 25-54 y of all race/ethnicity groups than women ages ≥55 y of corresponding race/ethnicity. In women ages ≥55 y, ID prevalence did not differ significantly across race/ethnicity. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy. CONCLUSIONS: ID prevalence was greater in Hispanic and black than white and Asian women ages 25-54 y. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.


Subject(s)
Anemia, Iron-Deficiency/epidemiology , Ethnicity/classification , Ferritins/blood , Hemochromatosis Protein/genetics , Transferrin/analysis , Adult , Aged , Anemia, Iron-Deficiency/genetics , Anemia, Iron-Deficiency/metabolism , Canada/epidemiology , Cross-Sectional Studies , Ethnicity/genetics , Female , Humans , Middle Aged , Mutation , Prevalence , United States/epidemiology
4.
Ann Hepatol ; 17(5): 871-879, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-30145563

ABSTRACT

INTRODUCTION AND AIM: We sought to identify independent risk factors for cirrhosis in HFE p.C282Y homozygotes in a cross-sectional study. MATERIAL AND METHODS: We evaluated 368 p.C282Y homozygotes who underwent liver biopsy and compared characteristics of those with and without cirrhosis. We performed multivariable logistic regression on cirrhosis with: age; sex; race/ethnicity; diabetes; blood pints/units donated voluntarily; erythrocyte pints/units received; iron supplement use; alcohol intake, g/d; body mass index, kg/m2; swollen/tender 2nd/3rd metacarpophalangeal joints; elevated alanine aminotransferase; elevated aspartate aminotransferase; steatosis/fatty liver; iron removed by phlebotomy, g; and GNPAT p.D519G positivity. RESULTS: Mean age of 368 participants (73.6% men) was 47 ± 13 (standard deviation) y. Cirrhosis was diagnosed in 86 participants (23.4%). Participants with cirrhosis had significantly greater mean age, proportion of men, diabetes prevalence, mean daily alcohol intake, prevalence of swollen/ tender 2nd/3rd metacarpophalangeal joints, mean serum ferritin, elevated alanine aminotransferase, elevated aspartate aminotransferase, and mean iron removed; and significantly fewer mean blood pints/units donated. GNPAT p.D519G positivity was detected in 82 of 188 participants (43.6%). In a multivariable model for cirrhosis, there were four significant positive associations: age (10-y intervals) (odds ratio 2.2 [95% confidence interval 1.5, 3.3]); diabetes (3.3; [1.1, 9.7]); alcohol intake (14 g alcohol drinks/d) (1.5 [1.2, 1.8]); and iron removed, g (1.3 [1.2, 1.4]). There was no statistical evidence of two-way interactions between these variables. CONCLUSION: In conclusion, cirrhosis in HFE p.C282Y homozygotes is significantly associated with age, diabetes, daily alcohol intake, and iron removed by phlebotomy, taking into account the effect of other variables.


Subject(s)
Hemochromatosis Protein/genetics , Hemochromatosis/genetics , Homozygote , Liver Cirrhosis/genetics , Mutation , Acyltransferases/genetics , Adult , Age Factors , Alcohol Drinking/adverse effects , Alcohol Drinking/epidemiology , Australia/epidemiology , Comorbidity , Cross-Sectional Studies , Diabetes Mellitus/epidemiology , Female , Genetic Predisposition to Disease , Hemochromatosis/diagnosis , Hemochromatosis/epidemiology , Hemochromatosis/therapy , Humans , Liver Cirrhosis/epidemiology , Liver Cirrhosis/pathology , Male , Middle Aged , Phenotype , Phlebotomy , Polymorphism, Single Nucleotide , Prevalence , Risk Assessment , Risk Factors , United States/epidemiology
5.
Hepatol Int ; 12(2): 83-86, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29589198

ABSTRACT

Although guidelines are available for hereditary hemochromatosis, a high percentage of the recommendations within them are not shared between the different guidelines. Our main aim is to provide an objective, simple, brief, and practical set of recommendations about therapeutic aspects of HFE hemochromatosis for p.Cys282Tyr (C282Y/C282Y) homozygous genotype, based on the published scientific studies and guidelines, in a form that is reasonably comprehensible to patients and people without medical training. This final version was approved at the Hemochromatosis International meeting on 12th May 2017 in Los Angeles.


Subject(s)
Hemochromatosis , Female , Humans , Male , Chelation Therapy/methods , Diet , Hemochromatosis/genetics , Hemochromatosis/therapy , Hemochromatosis Protein/genetics , Homozygote , Phlebotomy/methods
6.
Blood Cells Mol Dis ; 63: 15-20, 2017 03.
Article in English | MEDLINE | ID: mdl-27936396

ABSTRACT

BACKGROUND: GNPAT p.D519G positivity is significantly increased in HFE p.C282Y homozygotes with markedly increased iron stores. We sought to determine associations of p.D519G and iron-related variables with iron stores in p.C282Y homozygotes. METHODS: We defined markedly increased iron stores as serum ferritin >2247pmol/L (>1000µg/L) and either hepatic iron >236µmol/g dry weight or iron >10g by induction phlebotomy (men and women). We defined normal or mildly elevated iron stores as serum ferritin <674.1pmol/L (<300µg/L) or either age≥40y with iron ≤2.5g iron by induction phlebotomy or age≥50y with ≤3.0g iron by induction phlebotomy (men only). We compared participant subgroups using univariate methods. Using multivariable logistic regression, we evaluated associations of markedly increased iron stores with these variables: age; iron supplement use (dichotomous); whole blood units donated; erythrocyte units received as transfusion; daily alcohol consumption, g; and p.D519G positivity (heterozygosity or homozygosity). RESULTS: The mean age of 56 participants (94.6% men) was 55±10 (SD) y; 41 had markedly increased iron stores. Prevalences of swollen/tender 2nd/3rd metacarpophalangeal joints and elevated aspartate or alanine aminotransferase were significantly greater in participants with markedly increased iron stores. Only participants with markedly increased iron stores had cirrhosis. In multivariable analyses, p.D519G positivity was the only exposure variable significantly associated with markedly increased iron stores (odds ratio 9.9, 95% CI [1.6, 60.3], p=0.0126). CONCLUSIONS: GNPAT p.D519G is strongly associated with markedly increased iron stores in p.C282Y homozygotes after correction for age, iron-related variables, and alcohol consumption.


Subject(s)
Acyltransferases/genetics , Hemochromatosis Protein/genetics , Iron/metabolism , Mutation, Missense , Acyltransferases/metabolism , Adult , Age Factors , Aged , Alcohol Drinking , Female , Hemochromatosis Protein/metabolism , Homozygote , Humans , Male , Middle Aged
8.
PLoS One ; 11(9): e0163322, 2016.
Article in English | MEDLINE | ID: mdl-27661980

ABSTRACT

Both familial and sporadic porphyria cutanea tarda (PCT) are iron dependent diseases. Symptoms of PCT resolve when iron stores are depleted by phlebotomy, and a sequence variant of HFE (C282Y, c.843G>A, rs1800562) that enhances iron aborption by reducing hepcidin expression is a risk factor for PCT. Recently, a polymorphic variant (D519G, c.1556A>G, rs11558492) of glyceronephosphate O-acyltransferase (GNPAT) was shown to be enriched in male patients with type I hereditary hemochromatosis (HFE C282Y homozygotes) who presented with a high iron phenotype, suggesting that GNPAT D519G, like HFE C282Y, is a modifier of iron homeostasis that favors iron absorption. To challenge this hypothesis, we investigated the frequency of GNPAT D519G in patients with both familial and sporadic PCT. Patients were screened for GNPAT D519G and allelic variants of HFE (both C282Y and H63D). Nucleotide sequencing of uroporphyrinogen decarboxylase (URO-D) identified mutant alleles. Patients with low erythrocyte URO-D activity or a damaging URO-D variant were classified as familial PCT (fPCT) and those with wild-type URO-D were classified as sporadic PCT (sPCT). GNPAT D519G was significantly enriched in the fPCT patient population (p = 0.0014) but not in the sPCT population (p = 0.4477). Both HFE C282Y and H63D (c.187C>G, rs1799945) were enriched in both PCT patient populations (p<0.0001) but showed no greater association with fPCT than with sPCT. CONCLUSION: GNPAT D519G is a risk factor for fPCT, but not for sPCT.

11.
BMJ Support Palliat Care ; 5 Suppl 1: A27, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25960511

ABSTRACT

BACKGROUND: A multiagency group was set up in 2011 to encourage a more open approach to death, dying and bereavement in Fife, linked to the Scottish Alliance, Good Life Good Death Good Grief. AIM: To encourage and facilitate a more open approach to death, dying and bereavement in Fife through raising awareness and encouraging people across society to consider how they can further this agenda themselves. METHOD: The group has organised two well attended Fife wide conferences, with a wide range of participants from different organisations and the public, an all day drop-in event at a shopping centre, and a cafe event. Group members also produced some brief and practical information about Wills, Powers of Attorney, Advance Directives, Funeral Planning and the death registration process. Both conferences drew on the knowledge and skills of the participants as members of society and encouraged them to have confidence to take forward the agenda in their own way. RESULTS: The most recent conference in November 2014 was very well received. A high proportion of attendees reported that they would take forward some actions themselves either at home, in their workplace or in their communities. CONCLUSION: The group's work complements Good Life Good Death Good Grief nationally and provides a local focus to enable wider conversations about openness about death, dying and bereavement in Fife and greater knowledge of practical information.

13.
Hepatology ; 62(2): 429-39, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25605615

ABSTRACT

UNLABELLED: To identify polymorphisms associated with variability of iron overload severity in HFE-associated hemochromatosis, we performed exome sequencing of DNA from 35 male HFE C282Y homozygotes with either markedly increased iron stores (n = 22; cases) or with normal or mildly increased iron stores (n = 13; controls). The 35 participants, residents of the United States, Canada, and Australia, reported no or light alcohol consumption. Sequencing data included 82,068 single-nucleotide variants, and 10,337 genes were tested for a difference between cases and controls. A variant in the GNPAT gene showed the most significant association with severe iron overload (P = 3 × 10(-6) ; P = 0.033 by the likelihood ratio test after correction for multiple comparisons). Sixteen of twenty-two participants with severe iron overload had glyceronephosphate O-acyltransferase (GNPAT) polymorphism p.D519G (rs11558492; 15 heterozygotes, one homozygote). No control participant had this polymorphism. To examine functional consequences of GNPAT deficiency, we performed small interfering RNA-based knockdown of GNPAT in the human liver-derived cell line, HepG2/C3A. This knockdown resulted in a >17-fold decrease in expression of the messenger RNA encoding the iron-regulatory hormone, hepcidin. CONCLUSION: GNPAT p.D519G is associated with a high-iron phenotype in HFE C282Y homozygotes and may participate in hepcidin regulation.


Subject(s)
Acyltransferases/genetics , Genetic Variation , Hemochromatosis/genetics , Histocompatibility Antigens Class I/genetics , Iron Overload/genetics , Membrane Proteins/genetics , Alleles , Analysis of Variance , Blotting, Western , Case-Control Studies , Exome/genetics , Exome/physiology , Ferritins/blood , Hemochromatosis/physiopathology , Hemochromatosis Protein , Hep G2 Cells , Homozygote , Humans , Iron Overload/physiopathology , Liver Cirrhosis/genetics , Liver Cirrhosis/physiopathology , Male , Phenotype , Point Mutation , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction/methods , Sequence Analysis, Protein , Severity of Illness Index
14.
Biometals ; 27(1): 135-41, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24337410

ABSTRACT

We sought to examine the relationship between elevated transferrin saturation (TS) and measures of health status (telomere length and patient-reported health-related quality of life) to assess whether elevated TS is associated with negative patient outcomes beyond increased risk for morbidity and mortality, using a cross-sectional analysis of the Hemochromatosis and Iron Overload Screening Study supplemented with assays for leukocyte telomere length in adults ≥25 years old (n = 669). Among individuals with elevated TS (≥45 % for women and ≥50 % for men), who also had a usual source of care, only 5.2 % reported ever being told by a doctor that they had an elevated iron condition. In a fully adjusted general linear regression model controlling for demographic characteristics as well as health conditions associated with iron overload, elevated TS versus non-elevated TS was associated with worse general health status (60.4 vs. 63.8, P < 0.05), mental health status (76.5 vs. 82.2, P < 0.0001) and shorter telomere length (241.4 vs. 261.3, P < 0.05). Increased surveillance of elevated TS may be in order as elevated TS is associated with decreased health status and very few patients with elevated TS are aware of their condition.


Subject(s)
Quality of Life , Telomere/metabolism , Transferrin/analysis , Adult , Female , Humans , Male , Middle Aged , Real-Time Polymerase Chain Reaction , Telomere/genetics , Transferrin/metabolism
15.
Can J Gastroenterol ; 27(7): 390-2, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23862168

ABSTRACT

BACKGROUND: Many patients referred for an elevated serum ferritin level <1000 µg/L are advised that they likely have iron overload and hemochromatosis. AIMS: To determine the prevalence of HFE mutations in the hemochromatosis gene for 11 serum ferritin concentration intervals from 200 µg/L to 1000 µg/L in Caucasian participants in a primary care, population-based study. METHODS: The Hemochromatosis and Iron Overload Screening study screened 99,711 participants for serum ferritin levels, transferrin saturation and genetic testing for the C282Y and H63D mutations of the HFE gene. This analysis was confined to 17,160 male and 27,465 female Caucasian participants because the HFE C282Y mutation is rare in other races. Post-test likelihood was calculated for prediction of C282Y homozygosity from a ferritin interval. A subgroup analysis was performed in participants with both an elevated serum ferritin level and transferrin saturation. RESULTS: There were 3359 male and 2416 female participants with an elevated serum ferritin level (200 µg/L to 1000 µg/L for women, 300 µg/L to 1000 µg/L for men). There were 69 male (2.1%) and 87 female (3.6%) C282Y homozygotes, and the probability of being a homozygote increased as the ferritin level increased. Post-test likelihood values were 0.3% to 16% in men and 0.3% to 30.4% in women. CONCLUSIONS: Iron loading HFE mutations are unlikely to be the most common cause of an elevated serum ferritin level in patients with mild hyperferritinemia. Patients should be advised that there are many causes of an elevated serum ferritin level including iron overload.


Subject(s)
Ferritins/blood , Hemochromatosis/genetics , Histocompatibility Antigens Class I/genetics , Iron Overload/genetics , Membrane Proteins/genetics , Adult , Female , Genetic Testing , Hemochromatosis/diagnosis , Hemochromatosis Protein , Homozygote , Humans , Iron Overload/diagnosis , Likelihood Functions , Male , Mass Screening/methods , Mutation , Prevalence , Sex Factors , Transferrin/metabolism , White People/genetics
16.
Am J Med ; 126(5): 435-42, 2013 May.
Article in English | MEDLINE | ID: mdl-23510945

ABSTRACT

BACKGROUND: Many hospitalized Medical Service patients are at risk for venous thromboembolism in the months after discharge. We conducted a multicenter randomized controlled trial to test whether a hospital staff member's thromboprophylaxis alert to an Attending Physician before discharge will increase the rate of extended out-of-hospital prophylaxis and, in turn, reduce the incidence of symptomatic venous thromboembolism at 90 days. METHODS: From April 2009 to January 2010, we enrolled hospitalized Medical Service patients using the point score system developed by Kucher et al to identify those at high risk for venous thromboembolism who were not ordered to receive thromboprophylaxis after discharge. There were 2513 eligible patients from 18 study sites randomized by computer in a 1:1 ratio to the alert group or the control group. RESULTS: Patients in the alert group were more than twice as likely to receive thromboprophylaxis at discharge as controls (22.0% vs 9.7%, P <.0001). Based on an intention-to-treat analysis, symptomatic venous thromboembolism at 90 days (99.9% follow-up) occurred in 4.5% of patients in the alert group, compared with 4.0% of controls (hazard ratio 1.12; 95% confidence interval, 0.74-1.69). The rate of major bleeding at 30 days in the alert group was similar to that of the control group (1.2% vs 1.2%, hazard ratio 0.94; 95% confidence interval, 0.44-2.01). CONCLUSIONS: Alerting providers to extend thromboprophylaxis after hospital discharge in Medical Service patients increased the rate of prophylaxis but did not decrease the rate of symptomatic venous thromboembolism.


Subject(s)
Anticoagulants/therapeutic use , Medical Order Entry Systems , Pulmonary Embolism/prevention & control , Venous Thromboembolism/prevention & control , Aged , Aged, 80 and over , Anticoagulants/adverse effects , Female , Follow-Up Studies , Humans , Incidence , Male , Middle Aged , Patient Discharge , Physicians , Pulmonary Embolism/drug therapy , Pulmonary Embolism/epidemiology , Risk Factors , Venous Thromboembolism/drug therapy , Venous Thromboembolism/epidemiology
17.
Am J Hematol ; 88(6): 492-6, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23512844

ABSTRACT

Elevated body iron stores are associated with morbidity and mortality due to oxidative stress. Hereditary hemochromatosis, a common condition caused by HFE gene mutations, can lead to excess iron storage and disease but clinical penetrance of HFE gene mutations is low and many people with elevated iron stores lack HFE mutations. We analyzed data from the Hemochromatosis and Iron Overload Screening Study to assess the relationship among HFE genotype (individuals with either homozygous or compound heterozygous status for C282Y and/or H63D HFE mutations were defined as genotype positive, or G+), elevated iron phenotype (individuals exceeding gender-specific transferrin saturation and serum ferritin threshold levels were considered phenotype positive, or P+), and leukocyte telomere length, a marker of biological aging and cumulative oxidative stress. In unadjusted analyses in comparison to individuals who were G-P-, G+P- were not significantly different (OR 0.74; 95% CI 0.26-2.04), while the G+P+ (OR 2.03; 95% CI 1.15-3.56), and G-P+ (OR 2.24; 95% CI 1.5-3.29) had increased risk of short telomeres (<=25th percentile) rather than long telomeres (>=75th percentile). In analyses adjusting for age, gender, and race/ethnicity, the effect of individuals with elevated iron phenotypes having short telomeres persisted with G+P+ individuals (OR 1.94; 95% CI 1.02-3.72), and G-P+ individuals (OR 2.17; 95% CI 1.39-3.39) being significantly different from the G-P- group. In conclusion, elevated iron phenotype, but not HFE genotype, was associated with shortened telomeres. Further studies will be needed to determine whether telomere length provides a marker for morbidities specifically associated with iron overload.


Subject(s)
Hemochromatosis/genetics , Histocompatibility Antigens Class I/genetics , Iron/metabolism , Membrane Proteins/genetics , Telomere/ultrastructure , Adult , Female , Genotype , Hemochromatosis/blood , Hemochromatosis Protein , Histocompatibility Antigens Class I/metabolism , Humans , Iron/blood , Iron Overload/genetics , Iron Overload/metabolism , Male , Membrane Proteins/metabolism , Mutation , Phenotype , Telomere/chemistry , Telomere/metabolism
18.
Clin Gastroenterol Hepatol ; 11(7): 808-14, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23416278

ABSTRACT

BACKGROUND & AIMS: Celiac disease is an increasingly recognized disorder in Caucasian populations of European origin. Little is known about its prevalence in non-Caucasians. Although it is thought to be a cause of iron-deficiency anemia, little is known about the extent to which celiac disease contributes to iron deficiency in Caucasians, and especially non-Caucasians. We analyzed samples collected from participants in the Hemochromatosis and Iron Overload Screening study to identify individuals with iron deficiency and to assess the frequency of celiac disease. METHODS: We analyzed serum samples from white men (≥25 y) and women (≥50 y) who participated in the Hemochromatosis and Iron Overload Screening study; cases were defined as individuals with iron deficiency (serum ferritin level, ≤12 µg/L) and controls were those without (serum ferritin level, >100 µg/L in men and >50 µg/L in women). All samples also were analyzed for human recombinant tissue transglutaminase immunoglobulin A; positive results were confirmed by an assay for endomysial antibodies. Patients with positive results from both celiac disease tests were presumed to have untreated celiac disease, and those with a positive result from only 1 test were excluded from analysis. We analyzed HLA genotypes and frequencies of celiac disease between Caucasians and non-Caucasians with iron deficiency. RESULTS: Celiac disease occurred in 14 of 567 cases (2.5%) and in only 1 of 1136 controls (0.1%; Fisher exact test, P = 1.92 × 10(-6)). Celiac disease was more common in Caucasian cases (14 of 363; 4%) than non-Caucasian cases (0 of 204; P = .003). Only 1 Caucasian control and no non-Caucasian controls had celiac disease. The odds of celiac disease in individuals with iron deficiency was 28-fold (95% confidence interval, 3.7-212.8) that of controls; 13 of 14 cases with celiac disease carried the DQ2.5 variant of the HLA genotype. CONCLUSIONS: Celiac disease is associated with iron deficiency in Caucasians. Celiac disease is rare among non-Caucasians-even among individuals with features of celiac disease, such as iron deficiency. Celiac disease also is rare among individuals without iron deficiency. Men and postmenopausal women with iron deficiency should be tested for celiac disease.


Subject(s)
Anemia, Iron-Deficiency/epidemiology , Celiac Disease/complications , Iron Deficiencies , Racial Groups , Adult , Aged , Autoantibodies/blood , Female , Ferritins/blood , Humans , Immunoglobulin A/blood , Male , Middle Aged , Serum/chemistry , Transglutaminases/immunology
19.
PLoS One ; 7(6): e38339, 2012.
Article in English | MEDLINE | ID: mdl-22761678

ABSTRACT

The existence of multiple inherited disorders of iron metabolism suggests genetic contributions to iron deficiency. We previously performed a genome-wide association study of iron-related single nucleotide polymorphisms (SNPs) using DNA from white men aged ≥ 25 y and women ≥ 50 y in the Hemochromatosis and Iron Overload Screening (HEIRS) Study with serum ferritin (SF) ≤ 12 µg/L (cases) and controls (SF >100 µg/L in men, SF >50 µg/L in women). We report a follow-up study of white, African-American, Hispanic, and Asian HEIRS participants, analyzed for association between SNPs and eight iron-related outcomes. Three chromosomal regions showed association across multiple populations, including SNPs in the TF and TMPRSS6 genes, and on chromosome 18q21. A novel SNP rs1421312 in TMPRSS6 was associated with serum iron in whites (p = 3.7 × 10(-6)) and replicated in African Americans (p = 0.0012).Twenty SNPs in the TF gene region were associated with total iron-binding capacity in whites (p<4.4 × 10(-5)); six SNPs replicated in other ethnicities (p<0.01). SNP rs10904850 in the CUBN gene on 10p13 was associated with serum iron in African Americans (P = 1.0 × 10(-5)). These results confirm known associations with iron measures and give unique evidence of their role in different ethnicities, suggesting origins in a common founder.


Subject(s)
Ethnicity/genetics , Hemochromatosis/genetics , Iron Overload/genetics , Iron/blood , Polymorphism, Single Nucleotide/genetics , Adult , Black or African American/genetics , Black or African American/statistics & numerical data , Asian People/genetics , Asian People/statistics & numerical data , Biomarkers/analysis , California/epidemiology , Female , Follow-Up Studies , Genotype , Hemochromatosis/blood , Hemochromatosis/epidemiology , Hispanic or Latino/genetics , Hispanic or Latino/statistics & numerical data , Humans , Iron Overload/blood , Iron Overload/epidemiology , Male , Membrane Proteins/genetics , Middle Aged , Prognosis , Receptors, Cell Surface/genetics , Serine Endopeptidases/genetics , White People/genetics , White People/statistics & numerical data
20.
Arch Biochem Biophys ; 525(1): 60-70, 2012 Sep 01.
Article in English | MEDLINE | ID: mdl-22684023

ABSTRACT

Cysteamine, a coenzyme A metabolite, induces duodenal ulcers in rodents. Our recent studies showed that ulcer formation was aggravated by iron overload and diminished in iron deficiency. We hypothesized that cysteamine is selectively taken up in the duodenal mucosa, where iron absorption primarily occurs, and is transported by a carrier-mediated process. Here we report that cysteamine administration in rats leads to cysteamine accumulation in the proximal duodenum, where the highest concentration of iron in the gastrointestinal tract is found. In vitro, iron loading of intestinal epithelial cells (IEC-6) accelerated reactive oxygen species (ROS) production and increased [(14)C]cysteamine uptake. [(14)C]Cysteamine uptake by isolated gastrointestinal mucosal cells and by IEC-6 was pH-dependent and inhibited by unlabeled cysteamine. The uptake of [(14)C]cysteamine by IEC-6 was Na(+)-independent, saturable, inhibited by structural analogs, H(2)-histamine receptor antagonists, and organic cation transporter (OCT) inhibitors. OCT1 mRNA was markedly expressed in the rat duodenum and in IEC-6, and transfection of IEC-6 with OCT1 siRNA decreased OCT1 mRNA expression and inhibited [(14)C]cysteamine uptake. Cysteamine-induced duodenal ulcers were decreased in OCT1/2 knockout mice. These studies provide new insights into the mechanism of cysteamine absorption and demonstrate that intracellular iron plays a critical role in cysteamine uptake and in experimental duodenal ulcerogenesis.


Subject(s)
Cysteamine/metabolism , Duodenal Ulcer/metabolism , Duodenum/metabolism , Iron/metabolism , Animals , Biological Transport/drug effects , Caco-2 Cells , Cystamine/metabolism , Cysteamine/analogs & derivatives , Cysteamine/pharmacology , Deferoxamine/pharmacology , Duodenal Ulcer/pathology , Duodenum/drug effects , Duodenum/pathology , Female , Gene Expression Regulation/drug effects , Humans , Intestinal Absorption/drug effects , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Intracellular Space/drug effects , Intracellular Space/metabolism , Iron/pharmacology , Iron Chelating Agents/pharmacology , Mice , Organ Specificity , Organic Cation Transport Proteins/antagonists & inhibitors , Organic Cation Transport Proteins/deficiency , Organic Cation Transport Proteins/genetics , Rats , Reactive Oxygen Species/metabolism , Sodium/metabolism
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