Immunological and clinical assessment of adult HIV patients following switch to second-line antiretroviral regimen in a large HIV Program in North-central Nigeria

Antiretroviral (ART) regimen switch is a common occurrence in resource-limited settings where patients present late for care or with an AIDS-defining event. ART regimen switch can be attributed to several factors emanating from either the individual, program or facility level. This retrospective study was carried out in a resource-limited comprehensive facility in North-central Nigeria. Treatment records of 4,206 Adult HIV/AIDS patients initiated on first line ART regimen from 2006 to 2013 were extracted and examined for switch to second line ART regimen for the purpose of this study after ethical clearance had been sought. Absolute CD4 count, World Health Organisation (WHO) clinical stage and viral load results at treatment initiation, point of switch to second line and at the end of 2014 (end-point for the study) were obtained. About 75% of the 4,206 patients initiated on first line highly active antiretroviral therapy (HAART) were retained in care and were still on first line HAART at the end of 2014 with a significant difference in median CD4 count, BMI, WHO clinical staging and viral load at baseline compared to the end of the study period. Out of the 4,206 adults patients initiated on first line HAART, 71 were later switched to second line regimen due to either first-line immunological or virological failures although only 57 patients without traces of co-infection were included in this study. At end-point, a very high (87.7%) WHO defined immunological response was achieved. The study revealed that although immunologic and virologic response in patients before ART regimen switch was low, it improved tremendously after switch to second line regimen in all patients including those with available viral load results. The study results showed a 96.5% retention rate of patients switched to second line HAART and a correlation between virological suppression and immunological response. Key words: Immunological assessment, virologic response, HIV diagnosis, first line regimen, second line regimen.