Treatment of an atazanivir associated grade 4 hyperbilirubinaemia with efavirenz

Unique Running Pattern and Mucosal Morphology Found in the Colon of Cotton Rats

Cotton rats are one of the experimental rodents used for testing different infectious and non-infectious diseases, including gastrointestinal tract pathology. However, their intestinal morphological characteristics are still poorly understood. Here, we clarified the anatomical and histological characteristics of the cecum and ascending colon (AC) of young (1–3-month old), adult (4–6-month old), and old (10–12-month old) cotton rats. The large intestine (LI) in cotton rats is composed of the cecum, AC, transverse and descending colons, and rectum, and is similar to that of other mammals. The AC begins with a double or triple spiral loop-like flexure (SLLF) and ends with a coupled horseshoe-like flexure (HSLF). A single longitudinal mucosal fold (SLMF) was found at the beginning of the AC along the mesentery line and developed with age. Furthermore, the SLMF contained several lymphatic nodules (LNs), indicating their role in digestive and immunological functions. Small and large protuberant LNs were found in the cecum and SLLF, respectively, whereas thin and flat LNs were observed in the HSLF and transverse colon, respectively. Regarding sex-related differences, adult females had a significantly longer AC with a higher number of SLLFs compared to males. The SLMF length and LN number were also longer and higher, respectively, in adult females compared to adult males. These are crucial findings, indicating the presence of sex-related differences in the morphology of the LI in cotton rats, and ours is the first study to discover a sex difference in the mammalian LI lining. Our study clarified the unique morphology of the LI in cotton rats, which could serve as the principal model for elucidating species-specific digestive tract functions and gastrointestinal disorders.

Atazanavir and other determinants of hyperbilirubinemia in a cohort of 1150 HIV-positive patients: results from 9 years of follow-up

Hyperbilirubinemia is common among patients exposed to atazanavir (ATV), but its long-term significance is not well documented. The objective was to analyze hyperbilirubinemia (incidence, regression, determinants, and outcome) among 1150 HIV-positive patients followed-up in a prospective cohort between 2003 and 2012. Cumulative incidence of hyperbilirubinemia grades 3-4 and its probability of regression were estimated using Kaplan-Meier method. Cox proportional hazards model was used to study the determinants. Generalized estimating equation (GEE) regression was used to evaluate the association between hyperbilirubinemia grades 3-4 and adverse health outcome. Eight years cumulative incidence of hyperbilirubinemia was 83.6% (95% CI:79.0-87.7) and 6.6% (95% CI:4.7-9.2) among ATV users and non-users, respectively. This clinical outcome fluctuated considerably, as most patients exposed to ATV (91%) regressed, transiently, to lower grade at some point during follow-up. Determinants were atazanavir (HR=147.90, 95% CI: 33.64-604.18), ritonavir (HR=5.18, 95% CI:2.33-11.48), zidovudine (HR=2.62, 95% CI:1.07-6.46), and age (HR=1.04 95% CI:1.01-1.08). Alcohol consumption and others non-antiretroviral medications including hepatotoxic and recreational drugs were not available for analyses. Incidence of hyperbilirubinemia was very high among ATV users and, although regression to lower grade was frequent in the clinical follow-up of these patients, this was usually transient as the mean level of bilirubin stayed at a relatively high level. Importantly, long-term hyperbilirubinemia was not associated with adverse health outcome.

Individualization of antiretroviral therapy

Antiretroviral therapy (ART) has evolved considerably over the last three decades. From the early days of monotherapy with high toxicities and pill burdens, through to larger pill burdens and more potent combination therapies, and finally, from 2005 and beyond where we now have the choice of low pill burdens and once-daily therapies. More convenient and less toxic regimens are also becoming available, even in resource-poor settings. An understanding of the individual variation in response to ART, both efficacy and toxicity, has evolved over this time. The strong association of the major histocompatibility class I allele HLA-B*5701 and abacavir hypersensitivity, and its translation and use in routine HIV clinical practice as a predictive marker with 100% negative predictive value, has been a success story and a notable example of the challenges and triumphs in bringing pharmacogenetics to the clinic. In real clinical practice, however, it is going to be the exception rather than the rule that individual biomarkers will definitively guide patient therapy. The need for individualized approaches to ART has been further increased by the importance of non-AIDS comorbidities in HIV clinical practice. In the future, the ideal utilization of the individualized approach to ART will likely consist of a combined approach using a combination of knowledge of drug, virus, and host (pharmacogenetic and pharmacoecologic [factors in the individual’s environment that may be dynamic over time]) information to guide the truly personalized prescription. This review will focus on our knowledge of the pharmacogenetics of the efficacy and toxicity of currently available antiretroviral agents and the current and potential utility of such information and approaches in present and future HIV clinical care.