Response to changes in antiretroviral therapy after genotyping in human immunodeficiency virus-infected children

Virological suppression in children and adolescents is not influenced by genotyping, but depends on optimal adherence to antiretroviral therapy

Objective

To evaluate the virological outcomes in children and adolescents infected with HIV-1 in Salvador, Bahia according to genotyping results.

Methods

We retrospectively evaluated the rates of virological suppression of children and adolescents submitted to HIV-1 genotyping test from January/2008 to December/2012. The participants were followed in the two referral centers for pediatric AIDS care, in Salvador, Brazil. Resistance mutations, drug sensitivity profiles, and viral subtypes were analyzed using the Stanford HIV-1 Drug Resistance Database. Adherence was estimated by drugs withdrawal at pharmacies of the two sites.

Results

101 subjects were included: 35 (34.6%) were drug-naïve, and the remaining 66 were failing ART. In drug-naïve group, 3 (8.6%), presented with NNRTIs resistance mutations, along with polymorphic mutations to PIs in most (82.8%) of them. Among the failing therapy group, we detected a high frequency (89.4%) of resistance mutations to PIs, NRTI (84.8%), and NNRTI (59.1%). Virological suppression after introduction/modification of genotyping-guided ART was achieved only for patients (53.1%) with drug withdrawal over 95%. Main detected HIV-1 subtypes were B (67.3%), F (7.9), C (1.9%), and recombinant forms (22.9%).

Conclusions

Despite the use of genotyping tests in guidance of a more effective antiretroviral regimen, poor adherence to ART seems to be the main determinant of low virological suppression rate for children and adolescents, in Salvador, Brazil.

Effect of HIV genotypic drug resistance testing on the management and clinical course of HIV-infected children and adolescents

The clinical utility of genotypic drug resistance testing (DRT) in HIV-infected children on antiretroviral therapy (ART) is not well understood. HIV-infected patients aged <19 years undergoing DRT for virological failure were retrospectively enrolled. Indications for DRT and changes in HIV RNA load were recorded. Between January 2000 and December 2006, 57 patients had DRT. The most common indication for DRT was poor ART adherence (57.7% of patients). ART was changed in 50.9% of patients after DRT. Poor adherence was cited by clinicians for not changing ART significantly more often than any other reason (47.3%, P < 0.001). After DRT, significant improvement in HIV RNA load occurred independent of ART changes, though patients whose ART was modified were more likely to become undetectable (31.5% versus 7.0%, P < 0.001). Poor adherence was a significant factor for ordering DRT and for not changing ART in HIV-infected children.

Human immunodeficiency virus type 1 (HIV-1) genotyping in Rio de Janeiro, Brazil: assessing subtype and drug-resistance associated mutations in HIV-1 infected individuals failing highly active antiretroviral therapy

In order to assess the human immunodeficiency virus type 1 (HIV-1) drug resistance mutation profiles and evaluate the distribution of the genetic subtypes in the state of Rio de Janeiro, Brazil, blood samples from 547 HIV-1 infected patients failing antiretroviral (ARV) therapy, were collected during the years 2002 and 2003 to perform the viral resistance genotyping at the Renageno Laboratory from Rio de Janeiro (Oswaldo Cruz Foundation). Viral resistance genotyping was performed using ViroSeq Genotyping System (Celera Diagnostic-Abbott, US). The HIV-1 subtyping based on polymerase (pol) gene sequences (protease and reverse transcriptase-RT regions) was as follows: subtype B (91.2%), subtype F (4.9%), and B/F viral recombinant forms (3.3%). The subtype C was identified in two patients (0.4%) and the recombinant CRF_02/AG virus was found infecting one patient (0.2%). The HIV-1 genotyping profile associated to the reverse transcriptase inhibitors has shown a high frequency of the M184V mutation followed by the timidine-associated mutations. The K103N mutation was the most prevalent to the non-nucleoside RT inhibitor and the resistance associated to protease inhibitor showed the minor mutations L63P, L10F/R, and A71V as the more prevalent. A large proportion of subtype B was observed in HIV-1 treated patients from Rio de Janeiro. In addition, we have identified the circulation of drug-resistant HIV-1 subtype C and are presenting the first report of the occurrence of an African recombinant CRF_02/AG virus in Rio de Janeiro, Brazil. A clear association between HIV-1 subtypes and protease resistance mutations was observed in this study. The maintenance of resistance genotyping programs for HIV-1 failing patients is important to the management of ARV therapies and to attempt and monitor the HIV-1 subtype prevalence in Brazil.

Management of antiretroviral therapy in neonates, children, and adolescents

There have been tremendous advances in the prevention of maternal-to-child transmission of HIV and treatment of HIV-infected children and adolescents. Although multiple classes of anti-HIV drugs are available that can control viral replication and stabilize immune function when used in combination, patients and their providers must also manage complex and frequently toxic regimens. This article updates our original report that summarizes official National Institutes of Health guidelines for the prevention of perinatal HIV infection and the management of pediatric and adolescent HIV infection and provides the most current updates on indications for therapy, recommended first-line therapy, criteria for changing therapy, salvage therapy, novel management strategies, and a comprehensive summary of available antiretroviral agents.

Newer treatments for HIV in children

PURPOSE OF REVIEW

Several new antiretroviral agents have been introduced into pediatric and adult use. This review will summarize information about these new agents and other recent advances in the care of HIV-infected children.

RECENT FINDINGS

New drugs like tenofovir, emtricitabine, and enfuvirtide are being rapidly introduced into antiretroviral treatments for adult patients. In addition, some well-established drugs are being modified to make them more convenient (specifically didanosine and stavudine). Unfortunately, pediatric data lag for these new agents, in some cases because of complicated pharmacokinetics in children. At the same time, critical information on how to use established drugs like nelfinavir and efavirenz in younger children is slowly becoming available. Although antiretroviral treatment in children has often been initiated at standard doses of milligrams per kilogram, and susceptibility to drug was presumed in individuals without a previous history of exposure, recent data show that some primary infections are caused by drug-resistant virus, and there is a tremendous variability in serum drug levels in children. Researchers and clinicians should consider the role of baseline antiretroviral susceptibility testing and therapeutic drug monitoring to identify the optimal treatment for each child.

SUMMARY

New therapeutic options for children with HIV infection are becoming available as the pharmacokinetics and best strategies for use of newer drugs are studied.

Management of Antiretroviral Therapy in Neonates, Children, and Adolescents

There have been tremendous advances in the prevention of mother-to-child transmission of HIV and treatment of HIV-infected children and adolescents. Although multiple classes of anti-HIV drugs are available that can control viral replication and stabilize immune function when used in combination, patients and their providers also must manage complex and frequently toxic regimens. This article summarizes official National Institutes of Health guidelines for the prevention of perinatal HIV infection and the management of pediatric and adolescent HIV infection, and provides the most current updates on indications for therapy, recommended first-line therapy, criteria for changing therapy, salvage therapy, and novel management strategies.