From Environment to Genome and Back: A Lesson from HFE Mutations

Hereditary hemochromatosis beyond hyperferritinemia: Clinical and laboratory investigation of the patient's profile submitted to phlebotomy in two reference centers in southern Brazil

Hereditary Hemochromatosis is a disorder characterized by iron deposition in several organs and hyperferritinemia. The most studied variants are linked to the HFE gene. In Brazil, surveys that characterize this population are scarce, with no sampling in the state of Rio Grande do Sul. Our objective is to carry out a data collection focusing on the profile of this population and the influence of the most frequently HFE variants. Two centers were enrolled: Hospital de Clínicas de Porto Alegre and Hospital São Vicente de Paulo. Patients with hyperferritinemia and undergoing phlebotomy were invited. Clinical data were collected, including HFE investigation. Among the descriptive data, the allele frequency of the C282Y variant (0.252) stands out, which differs from the national scenario. Systemic arterial hypertension was the most cited comorbidity. Differences between centers were observed, highlighting higher frequency of H63D cases in HSVP (p<0.01). Genotypes were stratified according to deleterious effect of C282Y variant. Higher transferrin saturation and number of phlebotomies were observed in the C282Y/C282Y cases (p<0.001). Positive family history for hyperferritinemia was more prevalent in compound heterozygotes (p<0.01). The results presented confirm the importance of encouraging such studies and reiterate the need for greater attention to this population.

A Haptoglobin Exon Copy Number Variant Associates With HIV-Associated Neurocognitive Impairment in European and African-Descent Populations

A common two-exon deletion distinguishes the gene encoding the free hemoglobin capturing protein—haptoglobin (HP)–into two alleles: HP1 and HP2. To evaluate the impact of this copy number variant (CNV) on neurocognitive impairment (NCI) in people living with HIV, we imputed this variant in 432 European-descent (EUR) and 491 African-descent (AFR) participants from the CNS HIV Antiretroviral Therapy Effects Research Study using an optimized imputation pipeline and evaluated its associations with NCI. At baseline, in AFR, the HP2 allele decreased the odds of NCI (defined by a global deficit score, GDS, ⩾0.5; Odds Ratio, OR = 0.584, p = 0.022). However, in EUR, HP2 increased the odds (OR = 2.081, p = 0.040) of NCI suggesting a detrimental effect. These effects were extended to longitudinal analyses using repeated measurements where the protective effect of the HP2 allele in AFR became marginally significant (p = 0.054) and in EUR the detrimental effect increased in significance (p = 0.037). In EUR, the HP2 allele slightly reduced the risk of NCI over time (OR = 0.028 per allele per year, p = 0.024). Further analyses of cognitive domain-specific impairment revealed that the HP-NCI effect was based on changes in learning, speed of information processing, and verbal domains over time differing by ancestry groups. Overall, these findings suggest that these functional HP CNV alleles influence the likelihood of NCI and contribute to changes in neurocognitive function over time in people living with HIV.

Genetics, Immunity and Nutrition Boost the Switching from NASH to HCC

Nonalcoholic fatty liver disease (NAFLD) is the leading contributor to the global burden of chronic liver diseases. The phenotypic umbrella of NAFLD spans from simple and reversible steatosis to nonalcoholic steatohepatitis (NASH), which may worsen into cirrhosis and hepatocellular carcinoma (HCC). Notwithstanding, HCC may develop also in the absence of advanced fibrosis, causing a delayed time in diagnosis as a consequence of the lack of HCC screening in these patients. The precise event cascade that may precipitate NASH into HCC is intricate and it entails diverse triggers, encompassing exaggerated immune response, endoplasmic reticulum (ER) and oxidative stress, organelle derangement and DNA aberrancies. All these events may be accelerated by both genetic and environmental factors. On one side, common and rare inherited variations that affect hepatic lipid remodeling, immune microenvironment and cell survival may boost the switching from steatohepatitis to liver cancer, on the other, diet-induced dysbiosis as well as nutritional and behavioral habits may furtherly precipitate tumor onset. Therefore, dietary and lifestyle interventions aimed to restore patients' health contribute to counteract NASH progression towards HCC. Even more, the combination of therapeutic strategies with dietary advice may maximize benefits, with the pursuit to improve liver function and prolong survival.

Genetics Is of the Essence to Face NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the commonest cause of chronic liver disease worldwide. It is closely related to obesity, insulin resistance (IR) and dyslipidemia so much so it is considered the hepatic manifestation of the Metabolic Syndrome. The NAFLD spectrum extends from simple steatosis to nonalcoholic steatohepatitis (NASH), a clinical condition which may progress up to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). NAFLD is a complex disease whose pathogenesis is shaped by both environmental and genetic factors. In the last two decades, several heritable modifications in genes influencing hepatic lipid remodeling, and mitochondrial oxidative status have been emerged as predictors of progressive hepatic damage. Among them, the patatin-like phospholipase domain-containing 3 (PNPLA3) p.I148M, the Transmembrane 6 superfamily member 2 (TM6SF2) p.E167K and the rs641738 membrane bound-o-acyltransferase domain-containing 7 (MBOAT7) polymorphisms are considered the most robust modifiers of NAFLD. However, a forefront frontier in the study of NAFLD heritability is to postulate score-based strategy, building polygenic risk scores (PRS), which aggregate the most relevant genetic determinants of NAFLD and biochemical parameters, with the purpose to foresee patients with greater risk of severe NAFLD, guaranteeing the most highly predictive value, the best diagnostic accuracy and the more precise individualized therapy.

Network pharmacology-based identification of the key mechanism of quercetin acting on hemochromatosis

Hemochromatosis is an iron overload disease, which lacks nutritional intervention strategies. This study explored the protective effect of quercetin on hemochromatosis and its possible mechanism through network pharmacology. We used Online Mendelian Inheritance in Man to screen the disease targets of hemochromatosis, and further constructed a potential protein interaction network through STITCH. The above-mentioned targets revealed by Gene enrichment analysis have played a significant role in ferroptosis, mineral absorption, basal cell carcinoma, and related signal pathways. Besides, the drug likeness of quercetin obtained by Comparative Toxicogenomics Database was evaluated by Traditional Chinese Medicine Systems Pharmacology, and potential drug targets identified by PharmMapper and similar compounds identified by PubChem were selected for further research. Moreover, gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed the relationship between quercetin and glycosylation. Furthermore, we performed experiments to verify that the protective effect of quercetin on iron overload cells is to inhibit the production of reactive oxygen species, limit intracellular iron, and degrade glycosaminoglycans. Finally, iron-induced intracellular iron overload caused ferroptosis, and quercetin and fisetin were potential ferroptosis inhibitors. In conclusion, our study revealed the correlation between hemochromatosis and ferroptosis, provided the relationship between the target of quercetin and glycosylation, and verified that quercetin and its similar compounds interfere with iron overload related disease. Our research may provide novel insights for quercetin and its structurally similar compounds as a potential nutritional supplement for iron overload related diseases.

Management of liver disease patients in different clinical situations during COVID-19 pandemic

Chronic liver diseases are common worldwide, especially in developing countries. The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/(COVID-19) leads to the infection of many patients with underlying chronic liver diseases. As a relatively new disease, management of COVID-19, in the context of chronic liver disease, is mainly based on the experience of the treating physician and the available data. In this review, we summarize the available evidence about the management of liver disease patients, in the context of COVID-19 infection, which can increase the severity of viral hepatitis B. Also, its clearance in HBV patients is delayed. A sixfold increased severity of COVID-19 was reported in obese patients with metabolic associated fatty liver disease (MAFDL). In patients with autoimmune liver disease (AILD), it is not recommended to change their immunosuppressive therapy (as long as they are not infected with COVID-19), in order to avoid a flare of liver disease. However, immunosuppressant drugs should be modified, in the case of infection with COVID-19. To date, no data suggest an increased risk or severity in metabolic liver diseases, such as hemochromatosis, Wilson's disease, or alpha-1 antitrypsin deficiency. Patients with liver cirrhosis should be carefully managed with minimum exposure to healthcare facilities. Basic investigations for follow-up can be scheduled at wider intervals; if patients need admission, this should be in COVID-19-clean areas. Patients with hepatocellular carcinomas may have a poor prognosis according to preliminary reports from China. The course of COVID-19 in liver transplant recipients on immunosuppression seems to have a benign course, based on few reports in children and adults. The hepatotoxicity of COVID-19 drugs ranges from mild liver enzyme elevation to a flare of underlying liver diseases. Therefore, the decision should be customized. Telemedicine can minimize the exposure of healthcare workers and patients to infection with COVID-19 and decrease the consumption of personal protective equipment.

A survey of lifestyle habits, physician counseling, and direct-to consumer genetic testing in patients with hereditary hemochromatosis

INTRODUCTION AND OBJECTIVES

The goal of this study was to assess lifestyle habits and physician counseling of patients with hereditary hemochromatosis (HH), and determine the prevalence of direct-to-consumer (DTC) genetic testing.

MATERIALS AND METHODS

A 52-question survey was created to collect information on lifestyle habits and physician counseling among patients with HH, and the use of DTC genetic testing of patients referred to a clinic for evaluation of HH. A multivariate logistic regression model was applied to identify predictors of DTC genetic testing use.

RESULTS

The survey was e-mailed to 379 patients, of which 101 responded (26.6%). Among patients with HH, 37% reported alcohol use more than once weekly and 50% reported red meat consumption. The use of a vitamin C supplement was reported by 38.9% of participants. Among patients with living children and siblings, physicians failed to recommend HH screening 15.3% and 21.2% of the time respectively. Thirty-one patients reported DTC genetic testing, of which 46.7% (14/31) reported their DTC genetic test screened for HH. Six (19%) of those patients were prompted to see a specialist in HH based on the results.

CONCLUSIONS

Among patients with HH, lifestyle habits that may impact iron stores are common, but not all receive appropriate counseling. Direct-to-consumer genetic testing is common, and physicians should be aware of its limitations when patients seek further evaluation for HH based on their test results.