Genotypic Resistance Testing of HIV-1 DNA in Peripheral Blood Mononuclear Cells.

HIV-1 DNA exists in nonintegrated linear and circular episomal forms and as integrated proviruses. In patients with plasma viremia, most peripheral blood mononuclear cell (PBMC) HIV-1 DNA consists of recently produced nonintegrated virus DNA while in patients with prolonged virological suppression (VS) on antiretroviral therapy (ART), most PBMC HIV-1 DNA consists of proviral DNA produced months to years earlier. Drug-resistance mutations (DRMs) in PBMCs are more likely to coexist with ancestral wild-type virus populations than they are in plasma, explaining why next-generation sequencing is particularly useful for the detection of PBMC-associated DRMs. In patients with ongoing high levels of active virus replication, the DRMs detected in PBMCs and in plasma are usually highly concordant. However, in patients with lower levels of virus replication, it may take several months for plasma virus DRMs to reach detectable levels in PBMCs. This time lag explains why, in patients with VS, PBMC genotypic resistance testing (GRT) is less sensitive than historical plasma virus GRT, if previous episodes of virological failure and emergent DRMs were either not prolonged or not associated with high levels of plasma viremia. Despite the increasing use of PBMC GRT in patients with VS, few studies have examined the predictive value of DRMs on the response to a simplified ART regimen. In this review, we summarize what is known about PBMC HIV-1 DNA dynamics, particularly in patients with suppressed plasma viremia, the methods used for PBMC HIV-1 GRT, and the scenarios in which PBMC GRT has been used clinically.

Impact of HIV-1 Resistance-Associated Mutations on Susceptibility to Doravirine: Analysis of Real-World Clinical Isolates.

Clinical management of human immunodeficiency virus type-1 (HIV-1) infection may be negatively impacted by either acquired or transmitted drug resistance. Here, we aim to extend our understanding of the impact of resistance-associated mutations (RAMs) on the susceptibility of clinical isolates to the nonnucleoside reverse transcriptase inhibitor (NNRTI) doravirine. Clinical isolates from people living with HIV-1 undergoing routine testing for susceptibility to doravirine and other approved NNRTIs (etravirine, rilpivirine, efavirenz, and nevirapine) were collected from August 2018 to August 2019. Susceptibility in the presence/absence of NNRTI and nucleos(t)ide reverse transcriptase inhibitor (NRTI) mutations was determined using cutoffs for relative fold change in inhibition (ratio of the 50% inhibitory concentration [IC50] of patient virus compared with the IC50 of a wild-type reference strain). Biological cutoffs of 3- to 15-fold change were investigated for doravirine, with preestablished cutoffs used for the other NNRTIs. Of 4,070 clinical isolates, 42.9% had ≥1 NNRTI RAM. More isolates were susceptible to doravirine (92.5-96.7%) than to etravirine (91.5%), rilpivirine (89.5%), efavirenz (81.5%), or nevirapine (77.5%). Based on a 3-fold cutoff, doravirine susceptibility was retained in 44.7-65.8% of isolates resistant to another NNRTI and 28.5% of isolates resistant to all other tested NNRTIs. The presence of NRTI RAMs, including thymidine analog mutations, was associated with doravirine hypersusceptibility in some isolates, particularly in the absence of NNRTI RAMs. These results support the favorable resistance profile of doravirine and are of particular importance given the challenge posed by both acquired and transmitted resistance.

Integration of Contact Tracing and Phylogenetics in an Investigation of Acute HIV Infection.

BACKGROUND: The integration of traditional contact tracing with HIV sequence analyses offers opportunities to mitigate some of the barriers to effective network construction. We used combined analyses during an outbreak investigation of spatiotemporally clustered acute HIV infections to evaluate if the observed clustering was the product of a single outbreak. METHODS: We investigated acute and recent HIV index cases reported in North Carolina from 2013 to 2014 and their reported contacts. Contact tracing networks were constructed with surveillance data and compared with phylogenetic transmission clusters involving an index case using available HIV-1 pol sequences including 1672 references. Clusters were defined as clades of 2 or more sequences with a less than 1.5% genetic distance and a bootstrap of at least 98% on maximum-likelihood phylogenies. RESULTS: In total, 68 index cases and 210 contacts (71 HIV infected) were reported. The contact tracing network involved 58 components with low overall density (1.2% statewide); 33% of first-degree contacts could not be located. Among 38 (56%) of 68 index cases and 34 (48%) of 71 contacts with sequences, 13 phylogenetic clusters were identified (size 2-4 members). Four clusters connected network components that were not linked in contact tracing. The largest component (n = 28 cases) included 2 distinct phylogenetic clusters and spanned 2 regions. CONCLUSIONS: We identified the concurrent expansion of multiple small transmission clusters rather than a single outbreak in a largely disconnected contact tracing network. Integration of phylogenetic analyses provided timely information on transmission networks during the investigation. Our findings highlight the potential of combined methods to better identify high-risk networks for intervention.

SARS-CoV-2 neutralizing antibody titers in maternal blood, umbilical cord blood, and breast milk.

OBJECTIVE: We quantified neutralizing SARS-CoV-2 antibody against spike protein (nAb) levels after vaccination and SARS-CoV-2 infection in maternal serum, cord blood, and breast milk and determined whether they correlate with levels of spike protein binding antibody. STUDY DESIGN: Women (n = 100) were enrolled on admission for delivery. Previous SARS-CoV-2 infection was defined by anti-nucleocapsid antibodies. Levels of nAb and binding antibodies against spike receptor binding domain were measured in maternal blood, cord blood, and milk. RESULTS: Maternal nAb levels were higher after vaccine and infection than vaccine alone but waned rapidly. Levels of nAb in cord blood and milk correlated with maternal levels and were higher in cord blood than maternal. Spike protein binding antibody levels correlated with nAb. CONCLUSION: SARS-CoV-2 vaccination near delivery may boost antibody-mediated immunity in the peripartum period. Neutralizing antibodies are passed transplacentally and into milk. Spike protein binding antibody may be a feasible proxy for nAb.

HIV-1 DNA Testing in Viremic Patients Identifies More Drug Resistance Than HIV-1 RNA Testing.

Background: The Department of Health and Human Services HIV-1 Treatment Guidelines recommend drug resistance testing in HIV-1 RNA to guide the selection of antiretroviral therapy in patients with viremia. However, resistance-associated mutations (RAMs) in HIV-1 RNA may reflect only the patient's current regimen and can be lost during prolonged absence of therapy. We determined if HIV-1 DNA testing can provide drug resistance information beyond that identified in contemporaneous plasma virus. Methods: This was a retrospective database review of results obtained for patients with viremia for whom commercial HIV-1 RNA and HIV-1 DNA drug resistance testing was ordered on the same day. Resistance-associated mutations and drug susceptibility calls were compared between paired tests, and the effect of HIV-1 viral load (VL) on test concordance was assessed using Spearmen's rho correlation. Results: Among 124 paired tests, more RAMs were identified in HIV-1 DNA in 63 (50.8%) cases, and in HIV-1 RNA in 11 (8.87%) cases. HIV-1 DNA testing captured all contemporaneous plasma virus RAMs in 101/117 (86.3%) cases and identified additional RAMs in 63/117 (53.8%) cases. There was a significant positive correlation between the viral load at the time of resistance testing and the percentage of plasma virus RAMs detected in HIV-1 DNA (rs = 0.317; P < .001). In 67 test pairs demonstrating pan-sensitive plasma virus, resistance in HIV-1 DNA was seen in 13 (19.4%) cases. Conclusions: HIV-1 DNA testing identified more resistance than HIV-1 RNA testing in most patients with viremia and may be informative in patients whose plasma virus reverts to wild-type following therapy discontinuation.

Pan-resistant HIV-1 emergence in the era of integrase strand-transfer inhibitors: a case report.

BACKGROUND: In 2019, WHO reported that the prevalence of HIV-1 drug resistance to first-line regimens of non-nucleoside reverse transcriptase inhibitors is increasing in countries with a low number of therapeutic options. This increasing prevalence of drug resistance is an important threat to ending the AIDS pandemic, as it compromises individual clinical outcomes and increases the risk of transmission. In countries with a high number of therapeutic options, little global information is available regarding the prevalence of multidrug-resistant HIV-1 infections, which presents a potential challenge for the clinical management of people with HIV. Even after the approval of two new antiretroviral drug classes in 2007, which were intended to help alleviate this problem, some cases of infection with HIV-1 that show limited susceptibility to the five available antiretroviral classes have been described. We did a thorough in-vitro evaluation of the drug resistance profile of HIV-1 from an observational case to show that five-class pan-resistant clinical cases do exist. METHODS: We investigated a case of a highly treatment-experienced Caucasian male with HIV-1 who had a poor virological response to previous combination antiretroviral therapy (ART) and who was not responding to a dolutegravir-based regimen. For the complete panel of approved antiretrovirals, we examined genotypic resistance using the Stanford HIV Drug Resistance Database interpretation algorithm, and we examined phenotypic resistance using the PhenoSense and Trofile assays. Using viral gp160 sequence analysis, we also explored the potential susceptibility of this virus to novel therapeutic drugs targeting viral envelope binding. FINDINGS: The individual was diagnosed with HIV-1 on Sept 29, 1989. Since starting antiretroviral treatment in 1995, the individual had received more than 14 different antiretroviral drugs over the course of his illness. In November, 2017, a blood sample was collected from the individual and we did drug resistance analysis tests. We found that this individual was infected with a pan-resistant HIV-1 subtype B strain that showed broad genotypic and phenotypic cross-resistance to all approved antiretroviral drugs, including the newest second-generation integrase inhibitors, dolutegravir and bictegravir. With no remaining clinical options available, except for investigational drugs, this case provides evidence that new antiretroviral drugs with different mechanisms of action are needed. INTERPRETATION: Our case report shows that HIV-1 multidrug cross-resistance remains an important concern, despite the extensive number of antiretroviral drugs currently available. Highly treatment-experienced patients, especially those who have been given suboptimal combination ART, can develop highly complex resistance-associated mutation patterns, conferring cross-resistance to all widely available ARTs. The identification and reporting of cases, such as the one described in this report, are needed to increase awareness of emerging trends that have the potential to affect patient management. FUNDING: None.

Five Antiretroviral Drug Class-Resistant HIV-1 in a Treatment-Naïve Patient Successfully Suppressed with Optimized Antiretroviral Drug Selection.

Transmitted HIV-1 exhibiting reduced susceptibility to protease and reverse transcriptase inhibitors is well documented but limited for integrase inhibitors and enfuvirtide. We describe here a case of transmitted 5 drug class-resistance in an antiretroviral (ARV)-naïve patient who was successfully treated based on the optimized selection of an active ARV drug regimen. The value of baseline resistance testing to determine an optimal ARV treatment regimen is highlighted in this case report.

A decade of HIV-1 drug resistance in the United States: trends and characteristics in a large protease/reverse transcriptase and co-receptor tropism database from 2003 to 2012.

BACKGROUND: Drug resistance testing and co-receptor tropism determination are key components of the management of antiretroviral therapy for HIV-1-infected individuals. The purpose of this study was to examine trends of HIV-1 resistance and viral evolution in the past decade by surveying a large commercial patient testing database. METHODS: Temporal trends of drug resistance, viral fitness and co-receptor usage among samples submitted for routine phenotypic and genotypic resistance testing to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), as well as for tropism determination were investigated. RESULTS: Within 62,397 resistant viruses reported from 2003 to 2012, we observed a decreasing trend in the prevalence of three-class resistance (from 25% to 9%) driven by decreased resistance to PIs (43% to 21%) and NRTIs (79% to 57%), while observing a slight increase in NNRTI resistance (68% to 75%). The prevalence of CXCR4-mediated entry among tropism testing samples (n=52,945) declined over time from 47% in 2007 to 40% in 2012. A higher proportion of CXCR4-tropic viruses was observed within samples with three-class resistance (50%) compared with the group with no resistance (36%). CONCLUSIONS: Decreased prevalence of three-class resistance and increased prevalence of one-class resistance was observed within samples reported between 2003 and 2012. The fraction of CXCR4-tropic viruses has decreased over time; however, CXCR4 usage was more prevalent among multi-class-resistant samples, which may be due to the more advanced disease stage of treatment-experienced patients. These trends have important implications for clinical practice and future drug discovery and development.

An open-label safety study of enfuvirtide injection with a needle-free injection device or needle/syringe: the Biojector 2000 Open-label Safety Study (BOSS).

Enfuvirtide (ENF) administration by needle/syringe is commonly associated with injection site reactions (ISRs). This study assessed ISRs and participant preference between a needle-free injection device (NFID) and a 27-gauge 1/2-inch needle/syringe (NS). A total of 349 participants with human immunodeficiency virus infection, who had difficulty tolerating long-term administration of ENF by NS, underwent randomization (2:1) to ENF administered twice daily by NFID for 8 weeks, or by NS for 4 weeks followed by NFID for 4 weeks. The objectives of the study were to compare ISRs associated with ENF injection using NFID or NS based on a composite endpoint, ISR incidence/severity, overall ISR scores, and discontinuations. In the NFID group, ISRs improved as the percentage of participants meeting the composite endpoint decreased from baseline (40.1%) to week 4 (25.4%) and remained stable at week 8 (21.2%). In the NS --> NFID group, the percentage meeting the composite endpoint worsened from baseline (36.5%) to week 4 (45.1%), but improved at week 8 (26.1%) after switching. Between-participant comparison showed a statistically significant greater improvement from baseline to week 4 in overall ISR score in the NFID group compared to the NS group. Within-participant comparison of the NS --> NFID group showed a significantly greater decrease in overall ISR score from baseline to week 8. In responses to a questionnaire, 87.2% of the participants surveyed preferred the NFID delivery system over NS. NFID is an alternative injection method that may reduce the incidence and severity of treatment-limiting ISRs associated with ENF administration.