{"id":2332,"date":"2006-08-03T17:47:03","date_gmt":"2006-08-03T16:47:03","guid":{"rendered":"http:\/\/moomango.co.uk\/htb\/?p=2332"},"modified":"2013-12-06T17:30:25","modified_gmt":"2013-12-06T17:30:25","slug":"phenotypic-nnrti-resistance-and-genetic-diversity-in-antiretroviral-naive-women","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/2332","title":{"rendered":"Phenotypic NNRTI resistance and genetic diversity in antiretroviral naive women"},"content":{"rendered":"<p><strong>Polly Clayden, HIV i-Base<\/strong><\/p>\n<p><strong>A poster from Susan Eshleman and coworkers presented findings from a study in which they used a sensitive phenotypic assay to determine the frequency of antiretroviral resistance in drug naive Ugandan women who subsequently received single dose nevirapine for prevention of HIV-1 mother to child transmission in the HIVNET 012 trial.<\/strong><\/p>\n<p>The investigators tested 24 subtype A and 25 subtype C samples for nevirapine and efavirenz resistance and found 38 samples (78%) to have phenotypic NNRTI resistance. They found the frequency of resistant variants ranged from 0.3\u00961.9%.<\/p>\n<p>Twenty-one of the samples (half of those with phenotypic resistance) had known NNRTI resistance mutations at frequencies of 0.15\u00961.1%. Among the 13,870 RT isolates, the NNRTI-resistant mutations K101E (2), K103N (1), V106A (12), V108I (2), Y181C (6), Y188C (6), Y188H (3), Y188C (5), M230L (2), P236L (1) and L283I (1) were present.<\/p>\n<p>Some isolates with phenotypic NNRTI resistance that lacked known NNRTI resistance mutations had unusual variants not present in the majority species. These variants that confer phenotypic resistance include: L100V, K102R, K103E\/R, K104R, I132L\/M\/T\/V, Y188N, M230I\/R\/V and L283C.<\/p>\n<p>The investigators summarised their findings:<\/p>\n<ul>\n<li>NNRTI-resistant viruses are present at low levels in most ARV drug naive Ugandan women.<\/li>\n<li>In 35% of these samples, phenotypic NNRTI resistance was not explained by IAS-defined NNRTI resistance mutations.<\/li>\n<li>Combinations of \u0093polymorphisms\u0094 result in decreased NNRTI susceptibility.<\/li>\n<li>The frequency of drug resistance varies among individuals suggesting that discrete viral populations have different levels of genetic diversity.<\/li>\n<li>A coupled reverse transcription\/mutation assay identifies patient-derived RT variants that may replicate with different levels of fidelity.<\/li>\n<\/ul>\n<p class=\"ref\">Reference:<\/p>\n<p class=\"ref\">Nissley DV, Church JD, LA Guay et al. Phenotypic NNRTI resistance and genetic diversity in drug-naive individuals. XV International HIV Drug Resistance Workshop, Sitges, Spain, July 2006. Abstract 138.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Polly Clayden, HIV i-Base A poster from Susan Eshleman and coworkers presented findings from a study in which they used a sensitive phenotypic assay to determine the frequency of antiretroviral resistance in drug naive Ugandan women who subsequently received single &hellip;<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,36],"tags":[112],"class_list":["post-2332","post","type-post","status-publish","format-standard","hentry","category-conference-reports","category-drug-resistance","tag-idrw-15th-2006"],"_links":{"self":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/2332","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/comments?post=2332"}],"version-history":[{"count":0,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/2332\/revisions"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/media?parent=2332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/categories?post=2332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/tags?post=2332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}