Prevalence of discordant immunologic and virologic responses in patients with AIDS under antiretroviral therapy in a specialized care center in Brazil

Abstract

SUMMARYSome patients under antiretroviral therapy (ART) do not reach immune recovery when the viral load becomes undetectable. This is called discordant immunologic and virologic responses. Its prevalence varies between 8% and 24%. This study describes its prevalence and the characteristics of the affected subjects in the outpatient clinic of a Brazilian specialized-care center. Of 934 patients on ART, 536 had undetectable viral loads. Prevalence was 51/536 or 9% (95% confidence interval: 6.6% to 11.4%). Median age at the beginning of ART was 37 years (interquartile range -IQR: 31 to 45). Male gender and mixed race predominated (76.5% and 47.1% respectively). AIDS-defining illnesses were absent at the beginning of ART in 60.8%. Fifty-one percent were taking protease inhibitors, 43.2% Efavirenz and 5.8% both. Median time on ART was 36 months (IQR: 17-81 months). Irregular treatment was recorded for 21.6%. ART had been modified for 63% prior to the study, and 15.7% had used monotherapy or double therapy. Median CD4 count was 255 cells/mm . Median viral load before ART was 4.7 log 10 copies/mL (IQR: 4.5-5.2). Discordant responders were not different from AIDS patients in general, but there was a high frequency of multiple schedules of treatment.

Immunological outcomes of Tenofovir versus Zidovudine-based regimens among people living with HIV/AIDS: a two years retrospective cohort study

“…Immunologic response after 6 months of ART indicates a favourable clinical outcome in HIV-1 infected patients regardless of virologic response [ 20 ]. Several studies has reported that as many as 8–40% of patients on ART do not show a significant increase in CD4+ cell count despite viral suppression [ 18 , 21 , 22 ]. Our finding, in general, is almost consistent with these studies.…”

Discordant Treatment Responses to Combination Antiretroviral Therapy in Rwanda: A Prospective Cohort Study

“…The frequency of immunological discordant treatment response in this study population was higher than that observed in several other studies, where the proportion ranged between 9% and 28%. [ 1 , 6 – 8 , 10 , 24 – 27 ] Immunological discordant treatment response remains an unsolved challenge to physicians involved in long-term HIV care and treatment. In agreement with most other studies we found that older age was a significant risk factor for immunological discordant treatment responses.…”

“…In agreement with most other studies we found that older age was a significant risk factor for immunological discordant treatment responses. [ 1 , 6 , 7 , 9 , 10 , 15 ] The degree of immune restoration is dependent on the thymic function; as thymic function decreases with age,[ 9 , 24 , 25 ] this may explain why older people are at higher risk of incomplete immune restoration. All our patients were on a regimen including a non-nucleoside reverse transcriptase inhibitor (NNRTI).…”

Possible role of plasma Galectin-9 levels as a surrogate marker of viremia in HIV infected patients on antiretroviral therapy in resource-limited settings

“…CD4 count is being used as a marker of treatment success and is a part of patient management under our programme also. However, immune-virologically discordant responses are known to occur in 8-24% of the patients on ART [7] reducing sensitivity and specificity of the test in detecting viremic individuals. Hemoglobin and total lymphocyte count have been studied and shown to be reliable predictors of successful treatment outcome comparable to the increase in CD4 count [8].…”