Resistencia a los inhibidores de la integrasa en niños con el virus de la inmunodeficiencia humana por transmisión vertical: primeros casos en Uruguay / Resistance to integrase inhibitors in children with vertically-transmitted human immunodeficiency virus: First cases in Uruguay

La resistencia a los antirretrovirales (ARV) es un problema de salud pública. Con el uso de inhibidores de la integrasa (INSTI) en pediatría, también comienzan a aparecer resistencias. El objetivo de esta comunicación es describir 3 casos con resistencia a los INSTI. Se describen 3 pacientes pediátricos con transmisión vertical del virus de la inmunodeficiencia humana (VIH). Iniciaron ARV de lactantes y preescolares, con mala adherencia al tratamiento, cursaron con diferentes planes secundarios a comorbilidades asociadas y fallas virológicas por resistencia. Los 3 casos clínicos describen la rápida aparición de resistencia frente a la falla virológica y el compromiso de los INSTI. La adherencia debe ser supervisada para detectar precozmente el aumento de la viremia. La falla virológica en un paciente tratado con raltegravir obliga a un rápido cambio de esquema ARV, ya que continuar utilizándolo podría favorecer nuevas mutaciones y resistencia a los INSTI de segunda generación.

Antiretroviral (ARV) drug resistance is a public health issue. Resistance has also been observed in the case of integrase strand transfer inhibitors (INSTIs) used in pediatrics. The objective of this article is to describe 3 cases of INSTI resistance. These are the cases of 3 children with vertically-transmitted human immunodeficiency virus (HIV). They were started on ARVs as infants and preschoolers, with poor treatment adherence, and had different management plans due to associated comorbidities and virological failure due to resistance. In the 3 cases, resistance developed rapidly as a result of virological failure and INSTI involvement. Treatment adherence should be monitored so that any increase in viremia can be detected early. Virological failure in a patient treated with raltegravir forces to a rapid change in ARV therapy because its continued use may favor new mutations and resistance to second-generation INSTIs.

Antiviral therapy against chronic hepatitis B in Brazil: high rates of lamivudine resistance mutations and correlation with HBV genotypes

The effectiveness of antiviral treatments of chronic hepatitis B has been poorly studied in Brazil. Here, hepatitis B virus (HBV) DNA positivity, drug resistance mutations and their association with HBV genotypes were evaluated in chronically HBV-infected patients under different drug regimens in Brazil. The study involved 129 patients under interferon or nucleos(t)ide analogue therapy for a median treatment time of 12 months. One hundred and five (81%) of these patients were treated with lamivudine (LAM), either in monotherapy or in combination with newer drugs, such as entecavir (ETV) or tenofovir (TDF). High (37.5-100%) rates of HBV DNA positivity were observed with all but one drug regimen (LAM + ETV). However, patients that were treated with ETV alone, TDF alone or with LAM combination therapies had a mean viral load that was 3-4 log lower than patients treated with LAM monotherapy. Of the patients treated with LAM, 47% developed resistance mutations. HBV genotypes A (59.1%), D (30.3%) and F (9.1%) were found. There was no association between the presence of LAM resistance mutations and genotypes, HBeAg status or treatment duration. Nevertheless, the rtM204V mutation was observed more frequently (12/13, 92%) in genotype A than in the others (p = 0.023). Six out of nine isolates that contained the rtM204I mutation belonged to genotype D and half of them displayed a single mutation. Genotype D isolates with the rtM204V variant preferentially displayed a triple mutation, while genotype A preferentially displayed a double mutation (p = 0.04).

A Low Viral Load Predicts a Higher Initial Virologic Response to Adefovir in Patients with Lamivudine-Resistant Chronic Hepatitis B

BACKGROUND/AIMS: Adefovir (ADV) is the preferred drug for treating lamivudine (LAM)-resistant hepatitis B. However, not all patients who face virologic breakthrough during LAM treatment respond to ADV. The aim of this study was to determine the factors associated with efficacy of ADV in LAM-resistant hepatitis B patients. METHODS: The medical records of 231 patients who received ADV due to LAM-resistance were reviewed. Efficacy was assessed by the initial virologic response (IVR), defined as hepatitis B virus (HBV) DNA not being undetectable by real-time PCR at 6 months of ADV treatment. RESULTS: Seventy patients (30%) achieved IVR. While 'add-on' modality, hepatitis B e antigen (HBeAg) negativity, and low baseline HBV DNA levels were associated with IVR in univariate analysis, multivariate analysis revealed HBeAg status and the DNA level to be the significant factors. The probability of IVR achievement increased sharply per each log10 copies/mL decrement in the baseline viral load, which was 133 times in patients who had HBV DNA or =10(8) copies/mL. CONCLUSIONS: Factors associated with the IVR were HBeAg negativity and a low baseline viral load. Therefore, when virologic breakthrough with genotypic resistance emerges during LAM therapy, ADV treatment should be considered immediately before further increases in viral load. Additional long-term follow-up data are warranted.