Safety of monitoring antiretroviral therapy response in HIV-1 infection using CD4+ T cell count at long-term intervals / Segurança do monitoramento da resposta à terapia antirretroviral em pacientes com infecção pelo HIV-1 através da contagem de linfócitos T CD4+ a intervalos mais longos / Seguridad en la monitorización de la respuesta a la terapia antirretroviral ante el VIH-1, usando el recuento celular CD4+ T en intervalos a largo plazo

Abstract: The latest Brazilian guideline recommended the reduction of routine CD4+ T cell counts for the monitoring of patients with human immunodeficiency virus type 1 (HIV-1) under combination antiretroviral therapy (cART). The aim of this study was to evaluate the safety of monitoring response to cART in HIV-1 infection using routine viral load at shorter intervals and CD4+ T cell count at longer intervals. CD4+ T cell counts and HIV-1 viral load were evaluated in 1,906 HIV-1-infected patients under cART during a three-year follow-up. Patients were stratified as sustained, non-sustained and non-responders. The proportion of patients who showed a CD4+ T > 350cells/µL at study entry among those with sustained, non-sustained and non-responders to cART and who remained with values above this threshold during follow-up was 94.1%, 81.8% and 71.9%, respectively. HIV-1-infected patients who are sustained virologic responders and have initial CD4+ T cell counts > 350cells/µL showed a higher chance of maintaining the counts of these cells above this threshold during follow-up than those presenting CD4+ T ≤ 350cells/µL (OR = 39.9; 95%CI: 26.5-60.2; p < 0.001). This study showed that HIV-1-infected patients who had sustained virologic response and initial CD4+ T > 350cells/µL were more likely to maintain CD4+ T cell counts above this threshold during the next three-year follow-up. This result underscores that the evaluation of CD4+ T cell counts in longer intervals does not impair the safety of monitoring cART response when routine viral load assessment is performed in HIV-1-infected patients with sustained virologic response.

Resumo: O último consenso brasileiro recomenda reduzir a rotina de contagem de linfócitos T CD4+ para monitorar os pacientes com HIV-1 sob terapia antirretroviral combinada (TARV). O estudo teve como objetivo avaliar a segurança do monitoramento à TARV na infecção pelo HIV-1, realizando a carga viral a intervalos mais curtos e a contagem de linfócitos T CD4+ a intervalos mais longos. Foram avaliadas a contagem de linfócitos T CD4+ e a carga viral do HIV-1 em 1.906 pacientes com HIV-1 em uso de TARV durante um seguimento de três anos. Os pacientes foram estratificados em: resposta sustentada, não sustentada e não respondedores. As proporções de pacientes com linfócitos T CD4+ > 350células/µL na linha de base do estudo entre de resposta sustentada, não sustentada e não respondedores à TARV e que permaneceram com valores acima desse limiar ao longo do seguimento foram 94,1%, 81,8% e 71,9%, respectivamente. Os pacientes com resposta virológica sustentada e que tinham contagem de T CD4+ > 350células/µL mostraram maior probabilidade de manter a contagem acima desse limiar durante o seguimento, quando comparados àqueles com T CD4+ ≤ 350células/µL (OR = 39,9; 95%CI: 26,5-60,2; p < 0,001). O estudo mostrou que pacientes HIV-1+ com resposta virológica sustentada e contagem de linfócitos T CD4+ > 350células/µL tinham maior probabilidade de manter a contagem de células T CD4+ acima desse limiar durante o seguimento de três anos subsequentes. O resultado corrobora que a contagem de linfócitos T CD4+ com intervalos mais longos não compromete a segurança do monitoramento da resposta à TARV quando a avaliação da carga viral é feita de rotina em pacientes HIV-1+ com resposta virológica sustentada.

Resumen: Las últimas directrices brasileñas recomendaron la reducción de la rutina en el recuento celular CD4+ T para pacientes con el virus de inmunodeficiencia humano tipo 1 (VIH-1), con terapia de combinación antirretroviral (cART por sus siglas en inglês). El objetivo de este estudio fue evaluar la seguridad de la monitorización de la respuesta a la cART en una infección por VIH-1, usando rutinas de carga viral en intervalos más cortos y recuento celular CD4+ T en intervalos más largos. Se evaluaron el recuento celular CD4+ T y la carga viral VIH-1 en 1.906 pacientes infectados con VIH-1 y con cART durante un seguimiento que duró tres años. Los pacientes fueron estratificados como constantes, inconstantes y sin respuesta. La proporción de pacientes que mostraron CD4+ T > 350células/µL en el estudio entran dentro del grupo de los constantes, inconstantes y sin respuesta al cART, y quienes permanecieron con valores por encima de este umbral durante los seguimientos fueron 94,1%, 81,8% y 71,9%, respectivamente. Los pacientes infectados por VIH-1 que cuentan con la respuesta virológica constante y tienen un recuento inicial CD4+ T > 350células/µL mostraron una oportunidad más alta de mantener el recuento de estas células por encima del umbral durante los seguimientos, respecto a quienes presentaban CD4+ T células ≤ 350células/µL (OR = 39,9; IC95%: 26,5-60,2; p < 0,001). Este estudio expuso que los pacientes infectados por VIH-1, que habían tenido una respuesta virológica constante e inicial CD4+ T > 350células/µL, eran más propensos a mantener el recuento de células CD4+ T por encima de este umbral durante los tres años posteriores de seguimiento. Este resultado destaca que la evaluación del cómputo de células CD4+ T en intervalos más largos no obstaculiza la seguridad al realizar una monitorización en la respuesta a cART, cuando la evaluación de la carga viral rutinaria se realiza en pacientes infectados por VIH-1 con una respuesta virológica constante.

HIV-1 genetic diversity and resistance to antiretroviral drugs among pregnant women in Ribeirão Preto (SP), Brazil. Cross-sectional study

ABSTRACT BACKGROUND: Increasing genetic diversity of HIV-1 and emergence of drug-resistant mutations may reduce the efficacy of antiretroviral therapy and prophylaxis that are used to prevent mother-to-child transmission. The aim of this study was to assess the genetic diversity and prevalence of drug-resistant mutations among HIV-infected pregnant women. DESIGN AND SETTING: Cross-sectional study at an outpatient clinic for infectious diseases within gynecology and obstetrics. METHODS: This study evaluated the dynamics of HIV-1 subtypes and the prevalence of transmitted and acquired drug-resistant mutations among 38 HIV-infected pregnant women (20 previously exposed to antiretroviral therapy and 18 naive), in Ribeirão Preto (SP), Brazil, between 2010 and 2011. Genotyping was performed by means of molecular sequencing of the protease and reverse transcriptase regions of the HIV-1 pol gene. RESULTS: Subtype B was identified in 84.2% of the samples, recombinant forms between B and F in 7.9%, subtype F1 in 5.3% and the recombinant form K/F in 2.6%. No mutation associated with transmitted drug resistance was detected in the samples from the naive pregnant women, whereas mutations associated with acquired drug resistance were found in 35.0% of the pregnant women previously exposed to antiretroviral therapy. CONCLUSION: The results showed that subtype B predominated, while there was low prevalence of sequences with transmitted drug resistance.

Classical and alternative macrophages have impaired function during acute and chronic HIV-1 infection

Abstract Objectives: Three decades after HIV recognition and its association with AIDS development, many advances have emerged – especially related to prevention and treatment. Undoubtedly, the development of Highly Active Antiretroviral Therapy (HAART) dramatically changed the future of the syndrome that we know today. In the present study, we evaluate the impact of Highly Active Antiretroviral Therapy on macrophage function and its relevance to HIV pathogenesis. Methods: PBMCs were isolated from blood samples and monocytes (CD14+ cells) were purified. Monocyte-Derived Macrophages (MDMs) were activated on classical (MGM-CSF+IFN-γ) or alternative (MIL-4+IL13) patterns using human recombinant cytokines for six days. After this period, Monocyte-Derived Macrophages were stimulated with TLR2/Dectin-1 or TLR4 agonists and we evaluated the influence of HIV-1 infection and Highly Active Antiretroviral Therapy on the release of cytokines/chemokines by macrophages. Results: The data were obtained using Monocyte-Derived Macrophages derived from HIV naïve or from patients on regular Highly Active Antiretroviral Therapy. Classically Monocyte-Derived Macrophages obtained from HIV-1 infected patients on Highly Active Antiretroviral Therapy released higher levels of IL-6 and IL-12 even without PAMPs stimuli when compared to control group. On the other hand, alternative Monocyte-Derived Macrophages derived from HIV-1 infected patients on Highly Active Antiretroviral Therapy released lower levels of IL-6, IL-10, TNF-α, IP-10 and RANTES after LPS stimuli when compared to control group. Furthermore, healthy individuals have a complex network of cytokines/chemokines released by Monocyte-Derived Macrophages after PAMP stimuli, which was deeply affected in MDMs obtained from naïve HIV-1 infected patients and only partially restored in MDMs derived from HIV-1 infected patients even on regular Highly Active Antiretroviral Therapy. Conclusion: Our therapy protocols were not effective in restoring the functional alterations induced by HIV, especially those found on macrophages. These findings indicate that we still need to develop new approaches and improve the current therapy protocols, focusing on the reestablishment of cellular functions and prevention/treatment of opportunistic infections.