Colonic Epithelial Angiotensin-Converting Enzyme 2 (ACE2) Expression in Blacks and Whites: Potential Implications for Pathogenesis Covid-19 Racial Disparities.

BACKGROUND: Covid-19 toll is disproportionate in Blacks although the mechanisms remain incompletely understood. From a biological perspective, several host proteins have received most attention as logical susceptibility targets. Specifically, angiotensin-converting enzyme 2 (ACE2) serves as the epithelial cell receptor and acts in concert with transmembrane protease serine 2 (TMPRSS2). Intriguingly, ACE2 can also suppress the inflammatory response and therefore may impact the severity of Covid-19 infections (from the exuberant immune response a.k.a. "cytokine storm"). We, therefore, assessed expression of ACE2 and TMPRSS2 in Blacks versus Whites. METHODS: Archived mucosal biopsies from colonoscopic biopsies of visually normal rectal mucosa without concurrent neoplasia or inflammation were used for this study. Total mRNA was isolated and subjected to real-time polymerase chain reaction for ACE2, and TMPRSS2 was assessed from non-Hispanic Blacks (n = 45) and non-Hispanic Whites (n = 38). GAPDH and beta-actin were used for normalization. Multivariable analysis was performed using Analyse-IT software. RESULTS: ACE2 and TMPRSS2 levels were not altered by gender, BMI, or age. ACE2 levels were lower in Blacks than Whites achieving statistical significance in multivariable (0.51-fold, p = 0.03) but not quite in univariable (p = 0.07) analysis. This downregulation was mirrored in TMRPSS2 in both univariable (p = 0.03) and multivariable analyses (0.41-fold, p = 0.02). Moreover, there was a strong correlation between ACE2 and TMPRSS2 levels (r-squared = 0.78). CONCLUSIONS: To our knowledge, this is the first report on racial differences inACE2 and TMPRSS2 mucosal expression. This may provide potential biological underpinnings for the disproportionately higher mortality of Covid-19 in Blacks and should spur future studies.

Quantification of gastric mucosal microcirculation as a surrogate marker of portal hypertension by spatially resolved subdiffuse reflectance spectroscopy in diagnosis of cirrhosis: a proof-of-concept study.

BACKGROUND AND AIMS: Portal pressure can be used to identify patients with chronic liver disease who have progressed to cirrhosis. Portal pressure can also provide accurate prognostication for patients with cirrhosis. However, there are no practical means for assessment of portal pressure. Although it is well established that the gastric mucosal blood supply increases in patients with cirrhosis, this has been difficult to quantify reproducibly. Our group has developed a novel spectroscopic technology called spatially resolved subdiffuse reflectance spectroscopy (SRSRS), which enables quantification of mucosal microcirculation. We aim to ascertain if quantification of the gastric mucosal microcirculation with SRSRS correlates with clinical evidence of portal hypertension. METHODS: Patients undergoing EGD for clinical indications had 10 measurements taken in the endoscopically normal gastric fundus via SRSRS probe to assess the microcirculation. Cases were defined as patients with cirrhosis (n = 18), and controls were those without evidence of liver disease (n = 18); this was corroborated with transient elastography. RESULTS: The blood volume fraction (P = .06) and subdiffuse reflectance (P = .02) from a shallow depth in the gastric fundus were higher in patients with cirrhosis than those without. These markers were combined to yield an overall optical marker that can differentiate patients with cirrhosis from controls with a sensitivity of 72% and specificity of 94% (area under receiver operating curve, 0.82). CONCLUSIONS: Spectroscopic quantification of gastric fundal mucosal microcirculation is a promising surrogate of clinical correlates of portal hypertension. This approach may represent a less-intrusive surrogate biomarker for liver disease prognostication and potentially response to therapy.

Sustained Improvement in Type 2 Diabetes Mellitus is Common After Treatment of Hepatitis C Virus With Direct-acting Antiviral Therapy.

GOALS: To determine whether diabetic patients with hepatitis C virus (HCV) treated with direct-acting antiviral agents have improved diabetes, accounting for change in both hemoglobin A1c (HbA1c) and diabetes medications, and whether any improvement was sustained. BACKGROUND: HCV infection is associated with an increased risk of diabetes, with improvement in glycemic control after eradication. There remains uncertainty about the durability and magnitude of this effect. STUDY: HbA1c and diabetes medications were recorded at 6-month intervals for 1.5 years pretreatment and posttreatment for 122 patients. Subjects were classified as having improved diabetes if there was a decrease in HbA1c≥0.5% with no increase in diabetes medications or a decrease in diabetes medications with a stable HbA1c. RESULTS: HbA1c at the nearest time point before treatment was 8.4%±1.9%, compared with 7.8%±1.7% after treatment, a mean difference of 0.6% [95% CI (0.2, 0.9), P<0.01]. A linear mixed effects model incorporating each subject's repeated measurements over time also demonstrated a reduction after treatment of 0.5% [95% CI, (0.3, 0.8), P<0.001]. Accounting for both HbA1c and diabetes medications, 42 of 122 (34%) had an improvement in diabetes after HCV treatment, and 20 of 28 (71%) of these subjects sustained improvement at 1.5 years follow-up. Prescription of insulin was associated with improved diabetes. CONCLUSIONS: Treatment of HCV with direct-acting antiviral agents was associated with improved diabetes in a significant portion of patients with an average reduction in HbA1c of clinically significant magnitude. Among responders, this effect was sustained over 1.5 years of follow-up.

Intensive Pharmacy Care Improves Outcomes of Hepatitis C Treatment in a Vulnerable Patient Population at a Safety-Net Hospital.

BACKGROUND: Treatment of hepatitis C virus (HCV) with direct-acting antiviral (DAA) regimens has resulted in high rates of sustained virologic response (SVR). Treatment of vulnerable populations may be improved by incorporating an on-site intensive specialty pharmacy (ON-ISP). AIMS: To describe outcomes of HCV treatment at a safety-net hospital and proportion of subjects achieving SVR for those using the ON-ISP compared to an off-site pharmacy (OFF-SP). METHODS: A retrospective cohort study of 219 subjects treated for HCV with DAA at Boston Medical Center was conducted. Subject characteristics, virologic response, and pharmacy services used were recorded. We used multivariable logistic regression to test the association between ON-ISP and SVR after adjusting for covariates. RESULTS: SVR occurred in 71% of subjects by intention-to-treat (73% among ON-ISP users vs 57% among OFF-SP users) and 95% completing treatment per-protocol (96% among ON-ISP users vs 87% among OFF-SP users). Adjustment for age, sex, ethnicity, insurance, fibrosis, prior treatment, and MELD revealed an increased likelihood of SVR among users of ON-ISP: OR 6.0 (95% CI 1.18-31.0). No significant difference in treatment delay or adverse events was seen among users of either pharmacy type. CONCLUSIONS: HCV treatment with DAA was well tolerated, but the rate of SVR was low (71%) compared to trials. This was due to loss to follow-up, as the per-protocol rate of SVR was much higher (95%). Use of ON-ISP was associated with an increase in SVR and may be valuable for improving care for vulnerable populations.

Pneumocystis jiroveci pneumonia in inflammatory bowel disease: when should prophylaxis be considered?

BACKGROUND: The incidence of inflammatory bowel disease (IBD) has increased over the past several decades with a corresponding increase in the number of patients on combination immunosuppressive therapy including corticosteroids, anti-metabolites and biologic agents. The exact incidence of pneumocystis jiroveci pneumonia (PJP) in IBD patients is unknown but there has been an increase in the number of reports of PJP in IBD patients on combination immunosuppressive therapy. METHODS: We evaluated the published literature describing PJP infections in IBD patients, as well as other non-HIV cohorts and identified risk factors for PJP infection in this group of patients. Prophylaxis and treatment regimens were reviewed. RESULTS: Corticosteroid therapy, lymphopenia (total lymphocyte count < 600 cells/mm), and age greater than 55 years appear to be risk factors for developing pneumocystis jiroveci pneumonia. In addition, PJP mortality is greater in the non-HIV cohort in contrast to the HIV population. No evidence-based guidelines for primary PJP prophylaxis exist to direct practice for gastroenterology providers. CONCLUSIONS: Better surveillance and reporting of opportunistic infections including PJP are needed to elucidate risk factors for acquisition of infection. Gastroenterology providers should continue to evaluate the need for PJP prophylaxis on a case-by-case basis to recognize patients who may benefit from primary PJP prophylaxis. In particular, older patients on corticosteroids, multiple immunosuppressive agents, and patients with lymphopenia should be considered for prophylaxis.

Serum fibrosis markers can predict rapid fibrosis progression after liver transplantation for hepatitis C.

Although recurrent hepatitis C virus (HCV) after liver transplantation (LT) is universal, a minority of patients will develop cirrhosis within 5 years of surgery, which places them at risk for allograft failure. This retrospective study investigated whether 2 serum fibrosis markers, serum hyaluronic acid (HA) and YKL-40, could be used to predict rapid fibrosis progression (RFP) post-LT. These markers were compared with conventional laboratory tests, histological assessment, and hepatic stellate cell activity (HSCA), a key step in fibrogenesis, as assessed by immunohistochemical staining for alpha-smooth muscle actin. Serum and protocol liver biopsy samples were obtained from 46 LT recipients at means of 5 +/- 2 (biopsy 1) and 39 +/- 6 (biopsy 2) months post-LT, respectively. RFP was defined as an increase in the fibrosis score >or= 2 from biopsy 1 to biopsy 2 (a mean interval of 33 +/- 6 months). The ability of parameters at biopsy 1 to predict RFP was compared with the areas under receiver operating characteristic curves (AUROCs). Of the 46 subjects, 15 developed RFP. Serum HA and YKL-40 performed significantly better than conventional parameters and HSCA in predicting RFP post-LT for HCV at biopsy 1, with AUROCs of 0.89 and 0.92, respectively. The accuracy of serum HA >or= 90 microg/L and YKL-40 >or= 200 microg/L in predicting RFP at biopsy 1 was 80% and 96%, respectively. In conclusion, we found that elevated levels of serum HA and YKL-40 within the first 6 months after LT accurately predicted RFP. Larger studies evaluating the role of serum HA and YKL-40 in post-LT management are warranted.

Alcohol consumption and HIV disease progression.

OBJECTIVE: To assess the relation between alcohol consumption and laboratory markers of HIV disease progression. METHODS: We prospectively assessed CD4 cell counts, HIV RNA levels, and alcohol consumption for up to 7 years in 595 HIV-infected persons with alcohol problems recruited between 1997 and 2003. We investigated the relation of these markers of HIV disease progression to alcohol consumption using longitudinal regression models controlling for known prognostic factors, including adherence and depressive symptoms, and stratified by antiretroviral therapy (ART) use. RESULTS: Among subjects who were not on ART, heavy alcohol consumption was associated with a lower CD4 cell count (adjusted mean decrease of 48.6 cells/microL compared with abstinence; P = 0.03) but not with higher log(10) HIV RNA. Among subjects who were on ART, heavy alcohol consumption was not associated with a lower CD4 cell count or higher log(10) HIV RNA. CONCLUSIONS: Heavy alcohol consumption has a negative impact on the CD4 cell count in HIV-infected persons not receiving ART. In addition to the known deleterious effects of alcohol on ART adherence, these findings suggest that avoiding heavy alcohol consumption in patients not on ART may have a beneficial effect on HIV disease progression.

Cost-effectiveness of treatment for hepatitis C in an urban cohort co-infected with HIV.

PURPOSE: Recent clinical trials have evaluated treatment strategies for chronic infection with hepatitis C virus (HCV) in patients co-infected with human immunodeficiency virus (HIV). Our objective was to use these data to examine the cost-effectiveness of treating HCV in an urban cohort of co-infected patients. METHODS: A computer-based model, together with available published data, was used to estimate lifetime costs (2004 US dollars), life expectancy, and incremental cost per year of life saved (YLS) associated with 3 treatment strategies: (1) interferon-alfa and ribavirin; (2) pegylated interferon-alfa; and (3) pegylated interferon-alfa and ribavirin. The target population included treatment-eligible patients, based on an actual urban cohort of HIV-HCV co-infected subjects, with a mean age of 44 years, of whom 66% had genotype 1 HCV, 16% had cirrhosis, and 98% had CD4 cell counts >200 cells/mm3. RESULTS: Pegylated interferon-alfa and ribavirin was consistently more effective and cost-effective than other treatment strategies, particularly in patients with non-genotype 1 HCV. For patients with CD4 counts between 200 and 500 cells/mm3, survival benefits ranged from 5 to 11 months, and incremental cost-effectiveness ratios were consistently less than $75,000 per YLS for men and women of both genotypes. Due to better treatment efficacy in non-genotype 1 HCV patients, this group experienced greater life expectancy gains and lower incremental cost-effectiveness ratios. CONCLUSIONS: Combination therapy with pegylated interferon-alfa and ribavirin for HCV in eligible co-infected patients with stable HIV disease provides substantial life-expectancy benefits and appears to be cost-effective. Overcoming barriers to HCV treatment eligibility among urban co-infected patients remains a critical priority.

Suppression of MUC1 synthesis downregulates expression of the epidermal growth factor receptor.

The transmembrane mucin, MUC1, is overexpressed on many human carcinoma cells, increasing their metastatic potential through decreased cell-cell and cell-matrix adhesion. These cellular changes are mediated both through the altered physical properties of the mucin itself and through the role of the MUC1 cytoplasmic domain as a signaling molecule. The epidermal growth factor receptor (EGFR) is also overexpressed in many cancers and both it and MUC1 constitute important therapeutic targets. In the present study, expression of MUC1 was downregulated by treatment of KB carcinoma cells with a MUC1 small interfering RNA resulting in an inhibition of cell proliferation and colony formation and an increase in cell-cell aggregation. Surprisingly, suppression of MUC1 also inhibited expression of EGFR at both the mRNA and protein levels whereas the reciprocal effect was not observed. These results demonstrate a role for MUC1 in the regulation of EGFR expression and suggest that MUC1 gene silencing may represent a novel therapeutic approach in the treatment of a variety of human cancers.

Expression of membrane-associated mucins MUC1 and MUC4 in major human salivary glands.

Mucins are high molecular weight glycoproteins secreted by salivary glands and epithelial cells lining the digestive, respiratory, and reproductive tracts. These glycoproteins, encoded in at least 13 distinct human genes, can be subdivided into gel-forming and membrane-associated forms. The gel-forming mucin MUC5B is secreted by mucous acinar cells in major and minor salivary glands, but little is known about the expression pattern of membrane-associated mucins. In this study, RT-PCR and Northern blotting demonstrated the presence of transcripts for MUC1 and MUC4 in both parotid and submandibular glands, and in situ hybridization localized these transcripts to epithelial cells lining striated and excretory ducts and in some serous acinar cells. The same cellular distribution was observed by immunohistochemistry. Soluble forms of both mucins were detected in parotid secretion after immunoprecipitation with mucin-specific antibodies. These studies have shown that membrane-associated mucins are produced in both parotid and submandibular glands and that they are expressed in different cell types than gel-forming mucins. Although the function of these mucins in the oral cavity remains to be elucidated, it is possible that they both contribute to the epithelial protective mucin layer and act as receptors initiating one or more intracellular signal transduction pathways.