Antiretroviral resistance and genetic diversity of human immunodeficiency virus type 1 isolates from the Federal District, Central Brazil

An overview of the therapeutic potential of regenerative medicine in cutaneous wound healing

The global burden of disease associated with wounds is an increasingly significant public health concern. Current treatments are often expensive, time-consuming and limited in their efficacy in chronic wounds. The challenge of overcoming current barriers associated with wound care requires innovative management techniques. Regenerative medicine is an emerging field of research that focuses on the repair, replacement or regeneration of cells, tissues or organs to restore impaired function. This article provides an overview of the pathophysiology of wound healing and reviews the latest evidence on the application of the principal components of regenerative medicine (growth factors, stem cell transplantation, biomaterials and tissue engineering) as therapeutic targets. Improved knowledge and understanding of the pathophysiology of wound healing has pointed to new therapeutic targets. Regenerative medicine has the potential to underpin the design of specific target therapies in acute and chronic wound healing. This personalised approach could eventually reduce the burden of disease associated with wound healing. Further evidence is required in the form of large animal studies and clinical trials to assess long-term efficacy and safety of these new treatments.

HIV-1 Genetic Diversity and Drug Resistance Mutations Among Treatment-Naive Adult Patients in Suriname

The molecular epidemiologic profile of HIV-1 in Suriname was determined through protease (PR) and reverse transcriptase (RT) sequences obtained from HIV-1 strains collected from 100 drug-naive HIV-1-infected persons. Subtype determination revealed that most viruses were of subtype B (94.9%) in both PR and RT genomic regions, followed by B/D recombinants (5.1%). Analysis of drug resistance mutations showed only one transmitted dug resistance mutation (TDRM) (V75M) in a single strain. The genetic data obtained can serve as a baseline for Suriname to monitor emerging mutations. This study reveals that the HIV-1 epidemic in Suriname is still characterized by a low TDRM rate (1%) and a low level of subtype diversity. However, both genes display a high genetic polymorphism. This high polymorphism may ultimately lead to drug resistance. Continuous monitoring of the baseline resistance is therefore a prerequisite to safeguard effective long-term treatment for people living with HIV-1 in Suriname.

Resistance-associated mutation prevalence according to subtypes B and non-B of HIV type 1 in antiretroviral-experienced patients in Minas Gerais, Brazil

The emergence of resistance-associated mutations to the antiretroviral agents and the genetic variability of HIV-1 impose challenges to therapeutic success. We report the results of genotype testing assays performed between 2002 and 2006 in 240 antiretroviral-experienced patients followed up in an HIV reference center in Brazil. Drug resistance mutations and viral subtypes were assessed through the algorithms from the Brazilian Genotyping Network (RENAGENO-Brazil) and from Stanford University. Mutation 184VI was the most prevalent (70%) and the thymidine analogue mutations that appeared most frequently were 215FY, 41L, 67N, and 210W, in this order. Among nonnucleoside reverse transcriptase inhibitor mutations, 103NS (32.5%) stood out. HIV subtype B was identified in 184 patients (76.7%). A significant increasing trend in the prevalence of non-B subtypes was observed during the study period (p=0.004). The main differences in prevalence of mutations among HIV-1 subtypes were related to viral protease, with 20MRI, 36I, and 89IMT more prevalent among non-B subtypes, and 84V, 10FR, 63P, 71LTV, and 77I more common in subtype B (p<0.05). Most mutations to etravirine had a prevalence lower than 10%, but at least one mutation to this drug was observed in 45% of the patients. In only 11 patients (4.6%) three mutations to etravirine were verified. Regional surveillance of the resistance profile and HIV-1 subtypes is crucial in the context of public health, to prevent the transmission of resistant strains and to guide the introduction of new drugs in a specific population.

Assessing subtype and drug-resistance-associated mutations among antiretroviral-treated HIV-infected patients

BACKGROUND

Several studies have reported an increasing number of therapeutic failures with antiretroviral drugs in HIV-infected patients. The emergence of viral-resistant strains is a major problem for the medical management of infected individuals. The aim of this study is to determine viral subtypes and drug-resistance mutations among antiretroviral-treated HIV-infected patients.

METHODS

A total of 42 antiretroviral-treated but still viremic HIV-infected patients were enrolled. The HIV pol regions were amplified and sequenced to determine subtypes and antiretroviral-resistant mutations.

RESULTS

The subtype distribution was 48% A/D recombinants, 43% subtype B, 5% subtype A and 5% CRF01-AE recombinants. Drug-resistant mutations were most common in subtype B (53%) and A/D recombinant strains (44%). Virus samples from 19% of participants had no drug-resistant mutations; 2, 2 and 76% of samples carried one, two and at least three drug-resistant mutations, respectively. The prevalence of nucleoside transcriptase inhibitor mutations was 76%, with M184V and L74V present in 60 and 38% of samples, respectively. The prevalence of nonnucleoside transcriptase inhibitor mutations was 74%, with P225H present in 55% of study specimens. The prevalence of protease inhibitor mutations was 45%, with major mutation L90M seen in 33% and minor mutation A71V in 36% of samples. Of note, the P225H and A71V are 'minor' drug-resistance mutations conferring only minimal drug-resistance phenotypes in the absence of major mutations.

CONCLUSION

Our study found a high prevalence of drug-resistant mutations in Iranian HIV-infected patients. Our data support the need for continued surveillance of resistance patterns to help guide therapeutic approaches and limit transmission of these variants.

Prevalence of HIV-1 Subtypes in Brazilian Children With Perinatally Acquired Infection

HIV-1 infection has increased among women in recent years. The HIV-1 env gene (structural gene) has the greatest variation in all the HIV gene regions. In this study, 58 samples from infants infected with HIV-1 via perinatal transmission were analyzed. All the 58 samples were submitted to Nested-polymerase chain reaction of the env gene region for posterior viral genotyping using EN 70 and EN 85 (first polymerase chain reaction) and EN 80 and EN 95 (second polymerase chain reaction) primers, with the product of the 682 base pair amplification. After Nested-polymerase chain reaction for genotyping, purification of the product, and direct sequencing in a MegaBace 1000 automatic sequencer, 56 genotypes were found in the 58 HIV-1-positive children of the study, where 47 (83.93%) were HIV-1 subtype B infected and 9 (16.07%) were HIV-1 subtype F1 infected. The results demonstrate the predominance of subtype B followed by subtype F in Southeast Brazil.

Antiretroviral resistance in individuals presenting therapeutic failure and subtypes of the human immunodeficiency virus type 1 in the Northeast Region of Brazil

This study aimed to analyze human immunodeficiency virus (HIV) mutation profiles related to antiretroviral resistance following therapeutic failure, and the distribution of hiv subtypes in the Northeast Region of Brazil. A total of 576 blood samples from AIDS patients presenting therapeutic failure between 2002 and 2004 were analyzed. The genotyping kit viroSeq was used to perform viral amplification in order to identify mutations related to hiv pol gene resistance. An index of 91.1% of the patients presented mutations for nucleoside reverse transcriptase inhibitors (nrti), 58.7% for non-nucleoside reverse transcriptase inhibitors (nnrti), and 94.8% for protease inhibitors (pi). The most prevalent mutations were 184V and 215E for nrti, 103N and 190A for nnrti. Most mutations associated with PIs were secondary, but significant frequencies were observed in codons 90 (25.2%), 82 (21.1%), and 30 (16.2%). The resistance index to one class of antiretrovirals was 14%, to two classes of antiretrovirals 61%, and to three classes 18.9%. Subtype B was the most prevalent (82.4%) followed by subtype F (11.8%). The prevalence of mutations related to nrti and nnrti was the same in the two subtypes, but codon analysis related to PI showed a higher frequency of mutations in codon 63 in subtype B and in codon 36 in subtype F. The present study showed that there was a high frequency of primary mutations, which offered resistance to nrti and nnrti. Monitoring patients with treatment failure is an important tool for aiding physicians in rescue therapy.

HIV type 1 subtype C and CB Pol recombinants prevail at the cities with the highest AIDS prevalence rate in Brazil

HIV-1 B is predominant in Brazil, but HIV-1 C has increasingly been reported in the south of the country. However, many samples clustering with clade C are actually a recombinant, with a small B segment at RT (CRF31). Samples (209) from the three cities with the highest aids prevalence rate are analyzed. Partial polymerase sequences from HIV RNA made it possible to determine HIV clades and recombination patterns and to identify primary drug resistance mutations (DRMs). The incidence was estimated with a BED assay. HIV-1 C and CRF31 patterns were twice as frequent as clade B at all sites, but the proportion of C and CRF31 patterns was significantly different among sites. The incidence estimate for SC was 2.6 persons-years. Infection in recent or younger cases showed no association with clade C. Surveillance DRM was observed in 8.3% (95% CI 5-13), mostly to NNRTIs. Clade F pol genomes had significantly more primary DRM.

Molecular screening shows extensive HIV-1 genetic diversity in Central West Brazil

BACKGROUND

Information is limited about HIV-1 subtypes circulating in less populated Brazilian areas where the AIDS epidemic is expanding, such as in the Central West region.

OBJECTIVE

To describe HIV-1 subtypes in patients from the States of Goias, Mato Grosso do Sul and Mato Grosso in Central West Brazil.

STUDY DESIGN

Heteroduplex mobility analysis of nested-PCR products from env (primers: ED5/ED12, ES7/ES8) and gag regions (primers: H1P202/H1G777, H1Gag1584/g17) of 406 HIV-1 isolates from Goias (n=271), Mato Grosso do Sul (n=85) and Mato Grosso (n=50) collected from 2001 to 2004.

RESULTS

Median age of patients was 26 years (1-79 range), 68.7% (279/406) females, 69.9% (269/385) sexual exposure, 14.3% parenteral risk, 15.8% vertical cases. Overall 69.9% (284/406) of HIV-1 subtypes were concordant B(env)/B(gag), 1.7% F(env)/F(gag) and 1% C(env)/C(gag). Discordant HIV-1 isolates were 14.5% (59/406), mainly B(env)/F(gag) and F(env)/B(gag) (49/59); five were B(env)/D(gag), four B(env)/C(gag) and one C(env)/D(gag). B/B and discordant B/F isolates were detected among all risk categories and among children and adults.

CONCLUSION

Extensive genetic diversity of HIV-1 was observed in Central West Brazil. Continued molecular studies should monitor the changing dynamics of HIV-1 over time especially in areas where the epidemic is growing.

A genotyping study of human immunodeficiency virus type-1 drug resistance in a small Brazilian municipality

In Brazil, surveillance studies on antiretroviral drug resistance among drug-naïve and treatment-experienced patients have focused primarily on patients living in large urban centers. As the epidemic spreads towards small municipalities and the innermost parts of the country, it will be essential to monitor the prevalence of antiretroviral drug resistance in these areas. We report the first survey on the prevalence of antiretroviral drug resistance in a small Brazilian municipality. Between July 1999 and March 2005, 72 adult human immunodeficiency virus type-1(HIV-1)-infected patients received care at the Municipal HIV/AIDS Program of the small, southeastern municipality of Miracema, state of Rio de Janeiro. A genotyping study of antiretroviral drug resistance was performed in 54 patients. Among 27 samples from treatment-experienced patients, 9 (33.3%) harbored strains with reduced drug susceptibility. Among these, 6 had reduced susceptibility to reverse transcriptase (RT) inhibitors and 3 to both RT and protease inhibitors. No primary antiretroviral drug resistance was recorded among 27 drug-naïve subjects. The relatively low prevalence of resistance mutations in the Miracema cohort argues against the concern that resource-poor settings should not implement widespread accessibility to standard of care antiretroviral combinations due to the possibility of sub-optimal adherence leading to the emergence and spread of drug-resistant strains.