HFE-associated hereditary hemochromatosis: overview of genetics and clinical implications for nurse practitioners in primary care settings

Hemochromatosis drives acute lethal intestinal responses to hyperyersiniabactin-producing Yersinia pseudotuberculosis

Hemachromatosis (iron-overload) increases host susceptibility to siderophilic bacterial infections that cause serious complications, but the underlying mechanisms remain elusive. The present study demonstrates that oral infection with hyperyersiniabactin (Ybt) producing Yersinia pseudotuberculosis Δfur mutant (termed Δfur) results in severe systemic infection and acute mortality to hemochromatotic mice due to rapid disruption of the intestinal barrier. Transcriptome analysis of Δfur-infected intestine revealed up-regulation in cytokine-cytokine receptor interactions, the complement and coagulation cascade, the NF-κB signaling pathway, and chemokine signaling pathways, and down-regulation in cell-adhesion molecules and Toll-like receptor signaling pathways. Further studies indicate that dysregulated interleukin (IL)-1β signaling triggered in hemachromatotic mice infected with Δfur damages the intestinal barrier by activation of myosin light-chain kinases (MLCK) and excessive neutrophilia. Inhibiting MLCK activity or depleting neutrophil infiltration reduces barrier disruption, largely ameliorates immunopathology, and substantially rescues hemochromatotic mice from lethal Δfur infection. Moreover, early intervention of IL-1β overproduction can completely rescue hemochromatotic mice from the lethal infection.

From Death to Health in 30 Days: A Hemochromatosis Case Report

BACKGROUND

Heredity hemochromatosis (HH) is an underdiagnosed genetic disease that can lead to life-threatening multisystem organ failure. Identifying and treating HH early can prevent the progression of the disease.

CASE PRESENTATION

For a 60-year-old white patient without obvious symptoms, it was a revelation to discover that he had HH. This patient, although receiving evidence-based care, ultimately required a liver transplant. As his condition deteriorated, the plan for this patient and his family involved working within an interdisciplinary team that included nurse practitioners and intensive care unit nurses.

DISCUSSION

The uniqueness of this case illustrates the crucial role of a health care team that persisted in differentiating the patient's diagnosis and continued to sustain both physical and emotional care throughout his hospitalization despite a poor prognosis. The patient felt support from this team during the course of his illness, from requiring life-supporting care in intensive care unit to returning home and resuming his normal activities of daily living.

Key-interventions derived from three evidence based guidelines for management and follow-up of patients with HFE haemochromatosis

Background

HFE-related hereditary haemochromatosis (HH) is a common autosomal recessive disorder with clinical manifestations ranging from asymptomatic disease to possible life-threatening complications. Cirrhosis, hepatocellular carcinoma, diabetes mellitus or osteoporosis can develop in HH patients not treated or monitored optimally. The purpose of this study was to develop key-interventions (KI’s) to measure and improve the quality of care delivered to patients diagnosed with HH.

Methods

A RAND-Modified Delphi method was used to develop KI’s. In the first round of a scoring form to prioritize the recommendations extracted from evidence-based guidelines was circulated between experts. The results of this survey were discussed in a consensus meeting, followed by a final appraisal of the selected recommendations. This resulted in a list of measurable KI’s.

Results

Initially, 41 key recommendations on screening, diagnosis and treatment/management were extracted from three existing guidelines on HH (European Association for the Study of the Liver, American Association for the Study of Liver Diseases and Dutch guideline on HH). Finally, a core set of 24 recommendations resulted in 15 KI’s.

Conclusions

This manuscript presents the results of the process to develop KI’s to measure and improve the quality of care for patients with HH.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1835-2) contains supplementary material, which is available to authorized users.

Effect of the Hemochromatosis Mutations on Iron Overload among the Indian β Thalassemia Carriers

BACKGROUND

Hereditary hemochromatosis is a disorder of iron metabolism characterized by increased iron absorption.HFE gene mutations C282Y and H63D are responsible for the majority of hereditary hemochromatosis cases.

METHODS

We tried to look at the effect of HFE mutations on the iron status. A total of 100 β thalassemia traits (BTT) with 100 normal individuals were screened for the C282Y and H63D mutations using PCR-RFLP. The serum ferritin levels were determined using ELISA kit.

RESULTS

We did not find the C282Y mutation in our study group. The allelic frequencies for H63D mutation did not differ significantly between β-thalassemia traits (8.5%) and normal controls (9%). ΒΤΤ with H63D genotype of H/D (143.16 ± 80.3 ng/ml) and D/D (504 ng/ml) showed higher ferritin levels as against H/H genotype (88.64 ± 92.43 ng/ml). The statistically significant difference was observed in the mean serum ferritin levels among the individuals showing H/H and D/D genotypes (P < 0.002) and H/D and D/D genotype (P < 0.01) in both the groups.

CONCLUSION

This suggests that iron load in BTT tends to aggravated with the co-inheritance of the H63D mutation. The mutant H63D gene showed the presence of haplotype 6 which is reported in the European population suggesting a common origin.

Acute Free-Iron Exposure Does Not Explain the Impaired Haemorheology Associated with Haemochromatosis

Introduction

Given the severity of the current imbalance between blood donor supply and recipient demand, discarded blood drawn from the routine venesections of haemochromatosis (HFE-HH) patients may serve as a valuable alternative source for blood banks and transfusion. We investigated whether functional or biochemical differences existed between HFE-HH and control blood samples, with particular focus upon the haemorheological properties, to investigate the viability of venesected blood being subsequently harvested for blood products.

Methods

Blood samples were collected from HFE-HH patients undergoing venesection treatment (n = 19) and healthy volunteers (n = 8). Moreover, a second experiment investigated the effects of a dose-response of iron (0, 40, 80, 320 mM FeCl₃) on haemorheology in healthy blood samples (n = 7). Dependent variables included basic haematology, iron status, haematocrit, red blood cell (RBC) aggregation (native and standardised haematocrit) and “aggregability” (RBC tendency to aggregate in a standard aggregating medium; 0.4 L/L haematocrit in a Dx70), and RBC deformability.

Results

Indices of RBC deformability were significantly decreased for HFE-HH when compared with healthy controls: RBC deformability was significantly decreased at 1–7 Pa (p < 0.05), and the shear stress required for half maximal deformability was significantly increased (p < 0.05) for HFE-HH. RBC aggregation in plasma was significantly increased (p < 0.001) for HFE-HH, although when RBC were suspended in plasma-free Dx70 no differences were detected. No differences in RBC deformability or RBC aggregation/aggregability were detected when healthy RBC were incubated with varying dose of FeCl₃.

Conclusion

HFE-HH impairs the haemorheological properties of blood; however, RBC aggregability was similar between HFE-HH and controls when cells were suspended in a plasma-free medium, indicating that plasma factor(s) may explain the altered haemorheology in HFE-HH patients. Acute exposure to elevated iron levels does not appear (in isolation) to account for these differences. Further consideration is required prior to utilising routine venesection blood for harvesting RBC concentrates due to the potential risk of microvascular disorders arising from impaired haemorheology.

Iron homeostasis and tumorigenesis: molecular mechanisms and therapeutic opportunities

Excess iron is tightly associated with tumorigenesis in multiple human cancer types through a variety of mechanisms including catalyzing the formation of mutagenic hydroxyl radicals, regulating DNA replication, repair and cell cycle progression, affecting signal transduction in cancer cells, and acting as an essential nutrient for proliferating tumor cells. Thus, multiple therapeutic strategies based on iron deprivation have been developed in cancer therapy. During the past few years, our understanding of genetic association and molecular mechanisms between iron and tumorigenesis has expanded enormously. In this review, we briefly summarize iron homeostasis in mammals, and discuss recent progresses in understanding the aberrant iron metabolism in numerous cancer types, with a focus on studies revealing altered signal transduction in cancer cells.