Michel Buset

Upper gastrointestinal endoscopic findings in the era of highly active antiretroviral therapy

The current literature suggests that there has been a decrease in opportunistic diseases among HIV‐infected patients since the widespread introduction of highly active antiretroviral therapy (HAART) in 1995.

Injury induced by fatty acids or bile acid in isolated human colonocytes prevented by calcium

Measurement of the modulation of the growth fraction of isolated normal colonocytes from adult subjects in primary monolayer culture was used as a sensitive quantitative assay to evaluate toxic effects of several endogenous compounds found within the colon. This assay was used to study the role of CaCl2 in blocking cell injury. When added simultaneously with the injurious agent, 5-10 mM CaCl2 blocked the toxicity of physiological concentrations of deoxycholic acid, oleic acid, palmitic acid and linoleic acid.

Comparison of Demographic Characteristics and Upper Gastrointestinal Endoscopy Findings in HIV-Positive, Antiretroviral-Treated Patients With and Without Helicobacter pylori Coinfection

Objectives:  We evaluated demographic characteristics in HIV‐positive patients receiving highly active antiretroviral therapy (HAART) who had upper gastrointestinal (UGI) symptoms requiring UGI endoscopy and compared the findings in patients with and without H. Pylori coinfection.

The role of upper gastrointestinal endoscopy in the era of modern antiretroviral therapy.

Objective Gastrointestinal disorders are common in HIV-positive patients and, in some cases, may be related to antiretroviral therapy (ART), making it difficult to determine the need for upper gastrointestinal (UGI) endoscopy. The primary aim of this study was to determine whether lymphocyte T CD4 cell counts were correlated with indications for endoscopy in these patients and with endoscopic diagnosis. Patients and methods We prospectively collected data from consecutive HIV-positive patients undergoing UGI endoscopy between 2007 and 2013, and included 265 patients who had been receiving ART for at least 6 months. Parameters studied were demographics, immune parameters, comorbidities, comedications, indications for endoscopy, and endoscopic, pathologic, and microbiologic findings. Results The most frequent indications for UGI endoscopy were gastroesophageal reflux, epigastric pain, and other. Peptic esophagitis, esophageal candidiasis, and normal endoscopy were the most common diagnoses. The prevalence rates of Helicobacter pylori infection and neoplasia were 26.4 and 1.8%, respectively. Patients with CD4+ counts 200 cells/&mgr;l or more had significantly lower rates of macrolide and nonmacrolide use, fewer comorbidities, and were less likely to have AIDS than patients with lower counts. They were also more likely to have normal UGI endoscopy and had a higher frequency of H. pylori infection. AIDS status and the presence of comorbidities were independent predictors of endoscopic abnormalities. Conclusion UGI endoscopy remains a key diagnostic procedure for HIV-positive patients with UGI symptoms. AIDS and comorbidities are risk factors for the presence of mucosal lesions among HIV-positive patients on ART.

Vasoconstrictive effect of portal blood in isolated dog kidney.

Humoral vasoactive substances coming from portal blood have been considered as a possible cause of renal dysfunction in cirrhotic patients. We have thus investigated the effect of perfusion of portal blood from anesthetized dogs on the isolated kidney functions. Both kidneys of a dog were simultaneously perfused on 2 Nizets pump oxygenators, one kidney serving as control for the other. Renal blood flow was decreased in kidneys perfused with portal blood, as compared to the paired control kidneys perfused with sus-hepatic blood (group A experiments). Addition of polymyxin B to the portal blood restored the renal blood flow to the control level (group B experiments). No significant changes appeared between experimental and control kidneys for glomerular filtration rate, urine output, sodium and water excretion, renin activity, angiotensin II levels, plasmatic PGE2 levels, in group A as well as in group B. We conclude that portal blood of dogs contains vasoactive substances reducing renal blood flow; their action is mediated neither by the renin-angiotensin system nor by changes in renal PGE2 production. The complete abolition of this effect by Polymyxin suggests that these substances may be endotoxins.

HIV-Helicobacter pylori Co-Infection: Antibiotic Resistance, Prevalence, and Risk Factors

Background Patients infected with human immunodeficiency virus (HIV) are living longer due to the availability of more potent treatments. However, prescription of antibiotics to treat or prevent infections in these patients may increase the likelihood of co-infection with antibiotic-resistant species. Aim To compare antimicrobial susceptibility of Helicobacter pylori (H. pylori) in HIV-positive and HIV-negative patients and assess risk-factors for resistance. Methods We prospectively collected data from consecutive HIV-positive and HIV-negative patients undergoing upper gastrointestinal endoscopy. Patients with H. pylori-positive gastric biopsies who had never received H. pylori treatment were included. Results Of the 353 patients included, 93 were HIV-positive and 260 HIV-negative. Among the HIV-positive patients, 56 (60%) had been infected for <10 years, the median CD4+ count was 493 cells/μl and median viral load was 61 copies/mL; 66 (71%) were receiving antiretroviral therapy. HIV-positive patients were more often male (p = 0.009), had a lower body mass index (p<0.0001), and had less frequently received antibiotics during the 12-months prior to the endoscopy (p<0.0001) than HIV-negative patients. HIV-positive patients were more likely to have H. pylori resistant to levofloxacin (p = 0.0004), metronidazole (p = 0.01), or multiple antibiotics (p = 0.006). HIV-positive Black Africans were more likely to have resistant strains than were HIV-negative Black Africans (p = 0.04). Ethnicity and HIV status were independent risk factors for H. pylori resistance in all patients and acquired immune deficiency syndrome (AIDS) and sex were risk factors in HIV-positive patients. Conclusions There was a higher prevalence of primary H. pylori-resistant strains in HIV-positive than in HIV-negative patients. AIDS and sex were predictors of H. pylori resistance in HIV-positive patients.