The Interplay of Microbiome Dysbiosis and Cardiovascular Disease.

The intricate ecosystem of the mammalian gut, which hosts a diverse microbiome, plays a vital role in various physiological functions. Trillions of bacteria within the gut contribute to host metabolism, immune modulation, energy homeostasis, and more. Emerging research highlights the gut microbiota's significant impact on cardiovascular diseases (CVDs), with intestinal dysbiosis identified as a risk factor for conditions such as obesity and diabetes, both linked to atherosclerosis. Chronic inflammation, pivotal in atherosclerosis, is influenced by the gut microbiome, where microbial signals, such as lipopolysaccharides, can translocate from the gut to trigger inflammatory responses. Diet has major effects on the gut microbiota, with the Western diet, rich in saturated fats, contributing to dysbiosis and elevated cardiovascular risks. Probiotics and prebiotics offer therapeutic potential in CVD management. Probiotics, or live microorganisms, exhibit antioxidant, anti-inflammatory, and cholesterol-lowering effects. Probiotics are most effective when given with prebiotics, with the former acting on the latter as substrate. Understanding the dynamic interplay between diet, gut microbiota, and CVD provides insights into preventive and therapeutic strategies.

Disseminated histoplasmosis in an HIV/AIDS transgender male-to-female with atypical and persistent GI manifestations.

Disseminated histoplasmosis is a rare complication of infection due to Histoplasma capsulatum. Typically, histoplasmosis is self-limiting and asymptomatic in infected individuals with immunocompetence. Disseminated disease, however, can arise in high-risk populations with primary or acquired cellular immunodeficiency including HIV/AIDS, transplant recipients, and those undergoing immunosuppressive therapy. Here we describe a unique case of extrapulmonary gastrointestinal histoplasmosis by infiltrative Peyer's patch disease with bone marrow involvement in a transgender HIV-infected woman.

Hemochromatosis: pathophysiology, evaluation, and management of hepatic iron overload with a focus on MRI.

INTRODUCTION: Hereditary hemochromatosis (HH) is an autosomal recessive disorder that occurs in approximately 1 in 200-250 individuals. Mutations in the HFE gene lead to excess iron absorption. Excess iron in the form of non-transferrin-bound iron (NTBI) causes injury and is readily uptaken by cardiomyocytes, pancreatic islet cells, and hepatocytes. Symptoms greatly vary among patients and include fatigue, abdominal pain, arthralgias, impotence, decreased libido, diabetes, and heart failure. Untreated hemochromatosis can lead to chronic liver disease, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Many invasive and noninvasive diagnostic tests are available to aid in diagnosis and treatment. MRI has emerged as the reference standard imaging modality for the detection and quantification of hepatic iron deposition, as ultrasound (US) is unable to detect iron overload and computed tomography (CT) findings are nonspecific and influenced by multiple confounding variables. If caught and treated early, HH disease progression can significantly be altered. Area covered: The data on Hemochromatosis, iron overload, and MRI were gathered by searching PubMed. Expert commentary: MRI is a great tool for diagnosis and management of iron overload. It is safe, effective, and a standard protocol should be included in diagnostic algorithms of future treatment guidelines.

Primer on Hepatitis C Virus Resistance to Direct-Acting Antiviral Treatment: A Practical Approach for the Treating Physician.

Treatment of hepatitis C virus has been vastly transformed by the arrival of all-oral, interferon-free, direct-acting antiviral regimens. Despite the high rate of success with these agents, a small portion of treated patients fail therapy and the emergence of viral resistance is the most common cause of treatment failure. Given the error-prone hepatitis C virus polymerase, baseline resistance-associated substitutions (RASs) may be present before direct-acting antiviral exposure. Clinicians need to understand the role of baseline RAS testing and the settings and manner in which the treatment regimens need to be customized based on the presence of RASs.

Viral hepatitis screening in transgender patients undergoing gender identity hormonal therapy.

BACKGROUND AND AIM: Viral hepatitis is a global health issue and can lead to cirrhosis, liver failure, and hepatocellular carcinoma. Guidelines for viral hepatitis screening in the transgender population do not exist. Transgender patients may be at higher risk for contracting viral hepatitis due to socioeconomic and behavioral factors. The aim of this study was to measure the quality of screening, prevalence, and susceptibility of viral hepatitis, and to identify barriers to screening in transgender patients undergoing gender identity hormonal therapy. METHODS: LGBTQ-friendly clinic visits from transgender patients older than 18 years in New York City from 2012 to 2015 were reviewed. RESULTS: Approximately 13% of patients were screened for any viral hepatitis on initial consultation. Screening rates for hepatitis C virus (HCV), hepatitis B virus (HBV), and hepatitis A virus (HAV) at any point were 27, 22, and 20%. HAV screening was performed in 28% of the female to male (FtM) patients and 16% of male to female (MtF) (P<0.05) patients. HBV screening was performed in 30% of FtM patients and 18% of MtF patients (P<0.05). Thirty-one percent of FtM, 24% of MtF, and 17% of genderqueer patients were tested for HCV (P>0.05). Prevalence of HCV, HBV, and HIV in FtM was 0, 0, and 0.44% and that in MtF was 1.78, 0.89, and 1.78%, respectively. Percentage of patients immune to hepatitis A in FtM and MtF subgroups were 55 and 47% (P>0.05). Percentage of patients immune to HBV in FtM and MtF subgroups were 54 and 48% (P>0.05). CONCLUSION: This study indicates a significant lack of hepatitis screening in the transgender population and a concerning proportion of patients susceptible to disease.

A pangenotypic, single tablet regimen of sofosbuvir/velpatasvir for the treatment of chronic hepatitis C infection.

INTRODUCTION: Hepatitis C virus (HCV) infects nearly 170 million people worldwide and is a leading cause of progressive liver damage, cirrhosis, and hepatocellular carcinoma. Curative therapies have historically relied on interferon-based treatments and were limited by significant toxicity and poor response rates, particularly among patients with prior treatment failure and advanced hepatic fibrosis. The recent advent of direct acting antiviral (DAA) agents which target key steps in the HCV viral life cycle has transformed the landscape of HCV treatment by offering highly effective and well tolerated interferon-free treatments. However, current therapies are genotype-specific and have variable efficacy amongst less prevalent HCV variants. Areas covered: This review covers the preclinical and clinical development of sofosbuvir/velpatasvir (SOF/VEL), an interferon-free, once daily, pangenotypic treatment for the treatment of chronic hepatitis C virus (HCV) infection. All relevant literature from 2014 through September of 2016 is included. Expert opinion: SOF/VEL offers the promise of a single tablet, interferon- and ribavirin-free treatment that has extremely high efficacy in persons with chronic HCV infection regardless of genotype, subtype, treatment history or fibrosis status. It is expected to play a major role on a global scale in the therapeutic armamentarium against this ubiquitous threat to human health.

Cardiovascular diseases and the liver.

The dual blood supply of the liver, originating from the portal vein and the hepatic artery, makes it relatively resistant to minor circulatory disturbances. However, hepatic manifestations of common cardiovascular disorders are frequently encountered in both the inpatient and outpatient setting. Beginning with the macro- and microcirculation of the liver, this article reviews the pathophysiology of hepatic blood flow and gives a detailed appraisal of ischemic hepatitis, congestive hepatopathy, and other less common hepatic conditions that arise when cardiovascular function is impaired.

Telaprevir: hope on the horizon, getting closer.

Standard therapy with pegylated interferon and ribavirin for chronic hepatitis C is effective in 40% to 50% of individuals with genotype 1 hepatitis C virus (HCV) infection and is associated with significant treatment-related toxicities. Newly developed small molecules that target key enzymes essential for HCV replication are in development. Telaprevir, a peptidomimetic inhibitor of the HCV NS3/4A protease, has shown great promise in early trials and is currently in advanced stages of clinical development. In treatment-naïve patients and those with previous treatment failure, the addition of telaprevir to standard interferon and ribavirin therapy is well tolerated and enhances rates of sustained virologic response while shortening the treatment duration. In this report, the current experience using telaprevir to treat chronic HCV infection as monotherapy and in combination with other agents is reviewed.

Hepatitis B and end-stage liver disease.

Hepatitis B virus (HBV) is the most common cause of chronic hepatitis and end-stage liver disease worldwide. Untreated, chronic hepatitis B acquired early in life results in cirrhosis, liver failure, or hepatocellular carcinoma in up to 40% of individuals. Until recently, the options for a patient who had end-stage hepatitis B cirrhosis were severely limited, but during the past 15 years great strides have been made in prevention and treatment of hepatitis B cirrhosis. This article reviews recent advances in the understanding of the natural history, prevention, and medical management of HBV-related end-stage liver disease.

Investigations of a common genetic variant in betaine-homocysteine methyltransferase (BHMT) in coronary artery disease.

Hyperhomocysteinemia, a risk factor for cardiovascular disease, can be caused by genetic mutations in enzymes of homocysteine metabolism. Homocysteine remethylation to methionine is catalyzed by folate-dependent methionine synthase, or by betaine-homocysteine methyltransferase (BHMT), which utilizes betaine as the methyl donor. Since genetic variants in folate-dependent remethylation have been reported to increase risk for cardiovascular disease and other common disorders, we screened BHMT for sequence changes that might alter risk for coronary artery disease (CAD). A variant in exon 6-R239Q-was identified. The frequency of this change was examined in 504 individuals who had undergone coronary angiography and were stratified into controls (those with no or mild disease) and cases (those with significant [>50% reduction in luminal diameter stenosis] 1-, 2-, 3-vessel disease). Although this variant did not affect plasma homocysteine, the QQ genotype was present in higher frequency in those with no or mild disease, compared with those with significant disease (11 vs. 6%), suggesting that it may decrease risk of CAD; a statistically-significant decrease was seen in the older subjects (13 vs. 7%). Multivariate analysis for the entire group revealed an odds ratio of 0.48 (95% CI: 0.21-1.06) for the QQ genotype; this association was similar in the younger (OR=0.36; 95% CI: 0.09-1.41) and older subjects (OR=0.42; 95% CI: 0.15-1.18). Our study suggests that the Q allele of the R239Q mutation may decrease the risk of CAD and that this variant warrants additional investigation of its relationship with the development of CAD as well as other homocysteine-dependent disorders.

Characterization of mutations in severe methylenetetrahydrofolate reductase deficiency reveals an FAD-responsive mutation.

Methylenetetrahydrofolate reductase (MTHFR) synthesizes 5-methyltetrahydrofolate, a major methyl donor for homocysteine remethylation to methionine. Severe MTHFR deficiency results in marked hyperhomocysteinemia and homocystinuria. Patients display developmental delay and a variety of neurological and vascular symptoms. Cloning of the human cDNA and gene has enabled the identification of 29 rare mutations in homocystinuric patients and two common variants [677C>T (A222V) and 1298A>C (E429A)] with mild enzymatic deficiency. Homozygosity for 677C>T or combined heterozygosity for both polymorphisms is associated with mild hyperhomocysteinemia. In this communication, we describe four novel mutations in patients with homocystinuria: two missense mutations (471C>G, I153M; 1025T>C, M338T), a nonsense mutation (1274G>A, W421X), and a 2-bp deletion (1553delAG). We expressed the 1025T>C mutation as well as two previously reported amino acid substitutions [983A>G (N324S) and 1027T>G (W339G)] and observed decreased enzyme activity at 10%, 36%, and 21% of control levels, respectively, with little or no effect on affinity for 5-methyltetrahydrofolate. One of these mutations, 983A>G (N324S), showed flavin adenine dinucleotide (FAD) responsiveness in vitro. Expression of these mutations in cis with the 677C>T polymorphism, as observed in the patients, resulted in an additional 50% decrease in enzyme activity. This report brings the total to 33 severe mutations identified in patients with severe MTHFR deficiency.