Pretreatment HIV-1 Resistance in Argentina: Results from the Second Surveillance Study Following World Health Organization Guidelines (2019).

More than 62,000 individuals are currently on antiretroviral treatment within the public health system in Argentina. In 2019, more than 50% of people on ART received non-nucleoside reverse transcriptase inhibitors (NNRTIs). In this context, the second nationwide HIV-1 pretreatment drug resistance surveillance study was carried out between April and December 2019 to assess the prevalence of HIV-1 drug resistance in Argentina using the World Health Organization guidelines. This was a nationwide cross-sectional study enrolling consecutive 18-year-old and older individuals starting ARVs at 19 ART-dispensing centers. This allowed us to estimate a point prevalence rate of resistance-associated mutations (RAMs) with a confidence interval (CI) of 5% (for the total population and for those without antiretroviral exposure). Four-hundred forty-seven individuals were included in the study. The prevalence of mutations associated with resistance was detected in 27.7% (95% CI 25.6-34.9%) of the population. For NNRTI, it was 19.6% (95% CI 16.3-24.5%), for integrase strand transfer inhibitor (INSTI) 6.1% (95% CI 6.1-11.9%), for nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) 3% (95% CI 1.9-5.9%), and for protease inhibitors 1.5% (95% CI 0.7-3.6%). Naive individuals had variants of resistance to NRTIs in 16.8% (95% CI 12.8-21.4) and 5.7% (95% CI 2.9-15.9) to INSTI. For experienced individuals, the prevalence of variants associated with resistance was 30.38% (95% CI 20.8-42.2) for NRTIs and 7.7% (95% CI 2.9-15.9) for INSTI. This study shows an increase in the frequency of nonpolymorphic RAMs associated with resistance to NNRTI. This study generates the framework of evidence that supports the use of schemes based on high genetic barrier integrase inhibitors as the first line of treatment and the need for the use of resistance test before prescribing schemes based on NNRTI. We report for the first time the presence of a natural polymorphism associated with the most prevalent recombinant viral form in Argentina and the presence of a mutation linked to first-line integrase inhibitors such as raltegravir.

Making Visible HTLV Infection in a Non-endemic Area of Argentina.

In Argentina, the human T-cell lymphotropic virus type 1 (HTLV-1) infection has been documented mainly among blood banks with a prevalence of ~0.02-0.046% for Buenos Aires city, 0.8% for the northeast, and 1% for the northwest; both areas are considered endemic for HTLV-2 and 1, respectively. Policies and specific guidelines for testing blood donors for HTLV are included since 2005. Screening for antibodies is performed at blood banks and confirmatory testing is performed at reference laboratories. There are no specific recommendations for the assistance of communities and individuals affected, nor referral to specialized clinics on the HTLV infection. In 2016, as a strategy of intervention, we opened a specialized clinical attendance in a referral infectious diseases public hospital for the comprehensive approach to patients with HTLV, offering follow-up and counseling for patients and their families for the early diagnosis of HTLV-1/2 and related diseases. During the study, 124 patients with presumptive HTLV positive diagnosis from blood bank, symptomatic patients (SPs), relatives, and descendants visited the unit. A total of 46 patients were HTLV positive (38 HTLV-1 and 8 HTLV-2). There were nine SPs (2 adult T-cell leukemia/lymphoma [ATL] and 7 HTLV-1-associated myelopathy/tropical spastic paraparesis [HAM/TSP]). All patients with HTLV-1 and-2 were offered to study their relatives. Two out of 37 (5.4%) descendants tested were positive for HTLV-1. Sexual partners were studied; among 6 out of 11 couples (54.5%) were found positive (5 HTLV-1 and 1 HTLV-2). Other relatives, such as mothers (1/2) and siblings (1/6), were positive for HTLV-1. According to the place of birth among HTLV-1 carriers, 58% were born in an endemic area or in countries where HTLV infection is considered endemic while for HTLV-2 carriers, 12.5% were born in an endemic area of Argentina. The proviral load (pVL) was measured in all, patients with HTLV-1 being higher in symptomatic compared with asymptomatic carriers. In addition, two pregnant women were early diagnosed during their puerperium and breastmilk replacement by formula was indicated. Inhibition of lactation was also indicated. Our study provides tools for a multidisciplinary approach to the infection and reinforces the importance of having specialized clinical units in neglected diseases, such as HTLV for counseling, clinical and laboratory follow-up, and providing useful information for patients for self-care and that of their families.

Prevalence of rilpivirine resistance in people starting antiretroviral treatment in Argentina.

BACKGROUND: Rilpivirine-based regimens are now preferred or alternative first-line regimens according to many HIV treatment guidelines. Recently, a surveillance study conducted in Argentina determined that prevalence of pretreatment resistance to first-generation non-nucleoside reverse transcriptase inhibitors (NNRTIs) was 10%. The aim of this study was to analyse the prevalence of resistance mutations to newer generation NNRTIs in the population starting ART in Argentina. METHODS: We analysed the prevalence of resistance mutations to rilpivirine and etravirine (according to the IAS list), obtained through a nationally representative pretreatment HIV-drug resistance (PDR) surveillance study performed in Argentina in 2014-2015. Briefly, 25 ART-dispensing sites throughout the country were randomly chosen to enrol 330 adults starting ART. Samples were processed with Trugene (Siemens)® and analysed using the Stanford algorithm. RESULTS: All 270 samples corresponding to participants with no prior exposure to antiretroviral drugs were included in this analysis. Median (IQR) age was 35 years (28-43); 66.7% were male; median (IQR) CD4+ T-cell count was 284 cells/mm3 (112-489). The prevalence of resistance to any antiretroviral was 16% (±5%) and prevalence of NNRTI RAMs was 13% (±4%). The prevalence of resistance to rilpivirine was 8% (±3%). Prevalence of resistance to etravirine was 4% (±3%). The most frequent mutations conferring resistance to rilpivirine were: E138A (n=6) and G190A (n=4). CONCLUSIONS: This PDR surveillance study showed concerning levels of HIV drug resistance (HIVDR) in Argentina, not only for first-generation NNRTIs but also to rilpivirine. In our setting, performing resistance testing would be necessary before prescription of ART even if a second-generation NNRTI-based regimen was used as first-line therapy.

Score de sensibilidad genotípico de tratamientos antirretrovirales en embarazadas naïve infectadas por VIH-1 / Genotypic sensitivity score of antiretroviral therapies in naïve HIV-1 infected pregnant women

Introducción: el score de sensibilidad genotípica (GSS) es una herramienta para predecir el resultado virológico del TARV. El objetivo de este estudio es comparar el GSS de tres tratamientos an-tirretrovirales (TARVs) en una población de embarazadas infectadas por VIH (EIV) naïve en Buenos Aires, Argentina. Materiales y Métodos: se analizaron las pruebas de resistencia de 47 EIV naïve en la ciudad de Buenos Aires (período 2008-2011), utilizan-do el algoritmo de la Universidad de Stanford-HIVdb program (pre-valencia de resistencia primaria del 21,2 %). La eficacia predicha de cada fármaco se computó como 1,00-0,75-0,50-0,25 y 0,00 para las cinco categorías HIVdb: desde susceptible a resistencia de alto nivel. El GSS se obtuvo con la suma de las puntuaciones de los fármacos individuales incluidos (GSS = 3, significa tres medicamentos total-mente activos). Tres TARVs se compararon: zidovudina+lamivudina más nevirapina (ART1), nelfinavir (ART2) o lopinavir/ritonavir (ART3). Resultados: se obtuvo un GSS de 3 en el 80,9 % con ART1 y el 91,5 % con ART2 y ART3. No hubo diferencia estadísticamente significati-va en la posibilidad de lograr un GSS de 3 entre los TARVs evaluados. Conclusiones: no hubo diferencia estadística en la probabilidad de proporcionar un régimen comple-tamente activo con un inhibidor de la proteasa o nevirapina. En nuestra opinión, un TARV con una alta barrera genética sería preferible en el contex-to de la alta prevalencia de resistencia primaria ob-servada

Background: The genotypic sensitivity score (GSS) is a tool to predict virological treatment outcome. The objective of this study is to compare the GSS of three antiretroviral treatment (ART) strategies in a population of naive pregnant women (NPW) in Buenos Aires city, Argentina. Methods: Resistance tests from 47 NPW were analyzed in the context of a sentinel resistance surveillance study in Buenos Aires city (period 2008-2011), considering the genotype interpretation system of the Stanford HIVdb program (prevalence of primary drug resistance of 21.2%). The predicted efficacy of each drug was scored either as 1.00-0.75-0.50-0.25 and 0.00 for the five HIVdb categories: from susceptible to high-level resistance. GSS was obtained with the sum of the scores for the individual drugs included in a regimen (GSS of 3 means three fully active drugs). GSS of three ARTs were compared: zidovudine+lamivudine plus either nevirapine (ART1), nelfinavir (ART2) or lopinavir/ritonavir (ART3). Results: A GSS of 3 was achieved in 80.9% with ART1 and 91.5% with both ART2 and ART3. There was no statistical difference in the possibility of achieving a GSS of 3 between the three ARTs evaluated. Conclusions: There was no statistical difference in the probability of providing a fully active regimen with either a protease inhibitor or nevirapine. In our opinion, an ART with a high genetic barrier backbone may be preferred in the context of the high prevalence of primary resistance observed

Kinetics of HIV-1 in cerebrospinal fluid and plasma in cryptococcal meningitis.

In order to determine HIV-1 kinetics in cerebrospinal fluid (CSF) and plasma in patients with cryptococcal meningitis (CM), we undertook a prospective collection of paired CSF/plasma samples from antiretroviral therapy-free HIV-infected patients with CM. Samples were obtained at baseline (S1) and at the second (S2) and third (S3) weeks of antifungal therapy. HIV-1 CSF concentrations were significantly lower in both S2 and S3 with respect to S1. Plasma concentrations remained stable. HIV-1 concentrations were higher in plasma than CSF in all cases. Patients who survived the episode of CM (but not those who died) showed a decrease in CSF viral load, what suggests different viral kinetics of HIV-1 in the CSF according to the clinical course of this opportunistic disease.

Acute retroviral syndrome and high baseline viral load are predictors of rapid HIV progression among untreated Argentinean seroconverters.

BACKGROUND: Diagnosis of primary HIV infection (PHI) has important clinical and public health implications. HAART initiation at this stage remains controversial. METHODS: Our objective was to identify predictors of disease progression among Argentinean seroconverters during the first year of infection, within a multicentre registry of PHI-patients diagnosed between 1997 and 2008. Cox regression was used to analyze predictors of progression (LT-CD4 < 350 cells/mm3, B, C events or death) at 12 months among untreated patients. RESULTS: Among 134 subjects, 74% presented with acute retroviral syndrome (ARS). Seven opportunistic infections (one death), nine B events, and 10 non-AIDS defining serious events were observed. Among the 92 untreated patients, 24 (26%) progressed at 12 months versus three (7%) in the treated group (p = 0.01). The 12-month progression rate among untreated patients with ARS was 34% (95% CI 22.5-46.3) versus 13% (95% CI 1.1-24.7) in asymptomatic patients (p = 0.04). In univariate analysis, ARS, baseline LT-CD4 < 350 cells/mm3, and baseline and six-month viral load (VL) > 100,000 copies/mL were associated with progression. In multivariate analysis, only ARS and baseline VL > 100,000 copies/mL remained independently associated; HR: 8.44 (95% CI 0.97-73.42) and 9.44 (95% CI 1.38-64.68), respectively. CONCLUSIONS: In Argentina, PHI is associated with significant morbidity. HAART should be considered in PHI patients with ARS and high baseline VL to prevent disease progression.

Variables that influence HIV-1 cerebrospinal fluid viral load in cryptococcal meningitis: a linear regression analysis.

BACKGROUND: The central nervous system is considered a sanctuary site for HIV-1 replication. Variables associated with HIV cerebrospinal fluid (CSF) viral load in the context of opportunistic CNS infections are poorly understood. Our objective was to evaluate the relation between: (1) CSF HIV-1 viral load and CSF cytological and biochemical characteristics (leukocyte count, protein concentration, cryptococcal antigen titer); (2) CSF HIV-1 viral load and HIV-1 plasma viral load; and (3) CSF leukocyte count and the peripheral blood CD4+ T lymphocyte count. METHODS: Our approach was to use a prospective collection and analysis of pre-treatment, paired CSF and plasma samples from antiretroviral-naive HIV-positive patients with cryptococcal meningitis and assisted at the Francisco J Muñiz Hospital, Buenos Aires, Argentina (period: 2004 to 2006). We measured HIV CSF and plasma levels by polymerase chain reaction using the Cobas Amplicor HIV-1 Monitor Test version 1.5 (Roche). Data were processed with Statistix 7.0 software (linear regression analysis). RESULTS: Samples from 34 patients were analyzed. CSF leukocyte count showed statistically significant correlation with CSF HIV-1 viral load (r = 0.4, 95% CI = 0.13-0.63, p = 0.01). No correlation was found with the plasma viral load, CSF protein concentration and cryptococcal antigen titer. A positive correlation was found between peripheral blood CD4+ T lymphocyte count and the CSF leukocyte count (r = 0.44, 95% CI = 0.125-0.674, p = 0.0123). CONCLUSION: Our study suggests that CSF leukocyte count influences CSF HIV-1 viral load in patients with meningitis caused by Cryptococcus neoformans.

HCV genotype distribution among HIV co-infected individuals in Argentina: relationship with host and viral factors.

Coinfection with hepatitis C virus (HCV) in individuals infected with HIV is associated with a higher incidence of liver injury hepatic decompensation, and decreased survival than that observed in an HIV-monoinfected population. While prevalence studies on HIV/HCV coinfection have been performed in the U.S. and in some European countries, little is known about HCV genotype distribution in Latin America. The main objective was to evaluate the HCV prevalence and genotypes among HIV co-infected patients, and their relationship with HCV viral load, serum ALT level and T lymphocyte CD4+ cell count. These data pursue to increase the knowledge from South America about a pressing problem from HIV-infected patients. Retrospectively collected specimens from 593 HIV-positive individuals in Argentina were tested for anti-HCV These were analyzed for HCV-RNA qualitatively and quantitatively. The HCV genotype was determined by the RFLP method. One hundred and twenty-nine (21.7%) HIV-infected individuals were anti-HCV positive; 65.9% of them exhibited detectable HCV-RNA. Genotype 1 (43, la/c; 9, 1b; and 5, 1a/c+1b) was present in 57, while 1, 14 and 13 were infected with genotype 2, 3 or a mix, respectively. Co-infected individuals were more likely to be male, without significant differences in age and CD4+ cell counts than HIV-monoinfected individuals. HCV infection prevalence in patients co-infected with HIV highlights the impending public health impact of this problem. Considering the increasing rate of HCV genotypes with lower response rates to treatment among HIV co-infected patients, antiretroviral therapy success might be jeopardized by HCV coinfection.

HCV genotype distribution among HIV co-infected individuals in Argentina: Relationship with host and viral factors / Distribución de los genotipos de HCV entre individuos co-infectados con HIV en Argentina: su relación con factores del huésped y del virus

Coinfection with hepatitis C virus (HCV) in individuals infected with HIV is associated with a higher incidence of liver injury, hepatic decompensation, anddecreased survival than that observed in an HIVmonoinfected population. While prevalence studies on HIV/HCV coinfection have been performed in theU.S. and in some European countries, little is known about HCV genotype distribution in Latin America.The main objective was to evaluate the HCV prevalence and genotypes among HIV co-infected patients, and their relationship with HCV viral load, serumALT level and T lymphocyte CD4+ cell count. These data pursue to increase the knowledge from South America about a pressing problem from HIV-infectedpatients. Retrospectively collected specimens from 593 HIV-positive individuals in Argentina were tested foranti-HCV. These were analyzed for HCV-RNA qualitatively and quantitatively. The HCV genotype was determined by the RFLP method. One hundred andtwenty-nine (21.7%) HIV-infected individuals were anti-HCV positive; 65.9% of them exhibited detectable HCV- RNA. Genotype 1 (43, 1a/c; 9, 1b;and 5, 1a/c+1b) was present in 57, while 1, 14 and 13 were infected with genotype 2, 3 or a mix, respectively.Co-infected individuals were more likely to be male, without significant differences in age and CD4+ cell counts than HIV-monoinfected individuals.HCV infection prevalence in patients co-infected with HIV highlights the impending public health impact of this problem. Considering the increasingrate of HCV genotypes with lower response rates to treatment among HIV co-infected patients, antiretroviraltherapy success might be jeopardized by HCV coinfection.

La coinfección con el virus de hepatitis C (HCV) en individuos infectados con HIV está asociada con una mayor incidencia de injuria y descompensación hepática,y un menor tiempo de supervivencia respecto de la población mono-infectada por HIV. Mientras que diferentesestudios de prevalencia de la coinfecciónHIV/HCV se han llevado a cabo en Estados Unidos y países de Europa, la información de la distribución degenotipos de HCV en Latinoamérica es escasa. El objetivo de este estudio fue evaluar la prevalencia de HCVy la distribución de sus genotipos entre pacientes coinfectados con HIV, y su relación con la carga viral deHCV, los niveles séricos de ALT y el recuento de linfocitos T CD4+. Estos datos pretenden incrementar el conocimiento desde la región de Sudamérica acerca de este acuciante problema en pacientes infectados con HIV.Retrospectivamente se colectaron especímenes desde 593 pacientes infectados con HIV en Argentina enquienes se investigó la presencia de anticuerpos anti-HCV. Se pesquisó además la presencia de RNA viral deHCV tanto cualitativa como cuantitativamente. El genotipo de HCV se determinó por la técnica de RFLP.Ciento veintinueve (21.7%) individuos infectados con HIV fueron positivos para anti-HCV; 65.9% de ellos exhibieron RNA de HCV detectable. El genotipo 1(43, 1a/c; 9, 1b; y 5, 1a/c+1b) se presentó en 57 individuos, en tanto que 1, 14 y 13 estaban infectados porlos genotipos 2, 3 o mezcla de ellos, respectivamente. Predominó el sexo masculino entre los individuos concoinfección, en tanto que no se advirtieron diferencias significativas respecto de los pacientes infectados sólocon HIV en lo referido a edad y recuento de linfocitos T CD4+. La prevalencia de infección por HCV en pacientescoinfectados con HIV resalta el impacto de esta problemática en la salud pública. Considerando la creciente tasa de genotipos de HCV con menor respuestaal tratamiento entre los pacientes coinfectados con HIV, el efecto...

[HBV and HCV co-infections in HIV positive patients in the "HAART era": new challenges]. / Coinfecciones por HBV y HCV en pacientes hiv positivos en la "era HAART": nuevos desafios.

Co-infections with HIV and HCV/HBV are frequently found due to the similar routes of transmission (sexual, parenteral and vertical). Since the introduction of highly active antiretroviral therapy (HAART) there has been a notably decrease in patients morbidity and mortality, nevertheless with the prolonged survival, many of these patients are at risk of developing chronic complication, secondary to the infection of hepatotropic viruses. End stage liver disease is one of the main causes of morbid-mortality among HIV patients in developed countries. Nowadays there are new available therapies, diagnostic and follow up techniques for HBV and HCV, what provides a better control of both co-infections.

Coinfecciones por HBV y HCV en pacientes HIV positivos en la era HAART: nuevos desafíos / HBV and HCV co-infections in HIV positive patients in the HAART era: new challenges

Las coinfecciones con virus de la hepatitis C (HCV) y/o virus de la hepatitis B (HBV) en pacientes infectados por el virus de la inmunodeficiencia humana (HIV) son un hallazgo frecuente en virtud de las similares vías de transmisión que estos agentes presentan (sexual, parenteral y vertical). Desde el advenimiento del tratamiento antirretroviral de alta eficiencia (TARV) se evidenció una marcada disminución en la morbi-mortalidad de los pacientes; sin embargo, ante la prolongación de su sobrevida, las complicaciones crónicas debidas a las coinfecciones con estos virus hepatotropos han cobrado importancia, convirtiéndose la enfermedad hepática en una de las primeras causas de morbi-mortalidad de los pacientes HIV positivos en los países desarrollados. Se disponen en la actualidad de nuevas terapias y métodos de diagnóstico y seguimiento para HBV y HCV, lo cual permite un mejor control de ambas coinfecciones.

Co-infections with HIV and HCV/HBV are frequently found due to the similar routes of transmission (sexual, parenteral and vertical). Since the introduction of highly active antiretroviral therapy (HAART) there has been a notably decrease in patients morbidity and mortality, nevertheless with the prolonged survival, many of these patients are at risk of developing chronic complication, secondary to the infection of hepatotropic viruses. End stage liver disease is one of the main causes of morbid-mortality among HIV patients in developed countries. Nowadays there are new available therapies, diagnostic and follow up techniques for HBV and HCV, what provides a better control of both co-infections.