Persistence of a Skewed Repertoire of NK Cells in People with HIV-1 on Long-Term Antiretroviral Therapy

HIV-1 infection greatly alters the NK cell phenotypic and functional repertoire. This is highlighted by the expansion of a rare population of FcRγ- NK cells exhibiting characteristics of traditional immunologic memory in people with HIV (PWH). Although current antiretroviral therapy (ART) effectively controls HIV-1 viremia and disease progression, its impact on HIV-1-associated NK cell abnormalities remains unclear. To address this, we performed a longitudinal analysis detailing conventional and memory-like NK cell characteristics in n = 60 PWH during the first 4 y of ART. Throughout this regimen, a skewed repertoire of cytokine unresponsive FcRγ- memory-like NK cells persisted and accompanied an overall increase in NK surface expression of CD57 and KLRG1, suggestive of progression toward immune senescence. These traits were linked to elevated serum inflammatory biomarkers and increasing Ab titers to human CMV, with human CMV viremia detected in approximately one-third of PWH at years 1-4 of ART. Interestingly, 40% of PWH displayed atypical NK cell subsets, representing intermediate stages of NK-poiesis based on single-cell multiomic trajectory analysis. Our findings indicate that NK cell irregularities persist in PWH despite long-term ART, underscoring the need to better understand the causative mechanisms that prevent full restoration of immune health in PWH.

The latency-reversing agent HODHBt synergizes with IL-15 to enhance cytotoxic function of HIV-specific T cells

IL-15 is under clinical investigation toward the goal of curing HIV infection because of its abilities to reverse HIV latency and enhance immune effector function. However, increased potency through combination with other agents may be needed. 3-Hydroxy-1,2,3-benzotriazin-4(3H)-one (HODHBt) enhances IL-15-mediated latency reversal and NK cell function by increasing STAT5 activation. We hypothesized that HODHBt would also synergize with IL-15, via STAT5, to directly enhance HIV-specific cytotoxic T cell responses. We showed that ex vivo IL-15 + HODHBt treatment markedly enhanced HIV-specific granzyme B-releasing T cell responses in PBMCs from antiretroviral therapy-suppressed (ART-suppressed) donors. We also observed upregulation of antigen processing and presentation in CD4+ T cells and increased surface MHC-I. In ex vivo PBMCs, IL-15 + HODHBt was sufficient to reduce intact proviruses in 1 of 3 ART-suppressed donors. Our findings reveal the potential for second-generation IL-15 studies incorporating HODHBt-like therapeutics. Iterative studies layering on additional latency reversal or other agents are needed to achieve consistent ex vivo reservoir reductions.

Varied Patterns of Decay of Intact Human Immunodeficiency Virus Type 1 Proviruses Over 2 Decades of Antiretroviral Therapy

Fourteen people with human immunodeficiency virus type 1 had longitudinal measurements of intact, defective, and total proviral DNA over the course of two decades of antiretroviral therapy. Three patterns of intact proviral DNA decay were revealed: (1) biphasic decline with markedly slower second-phase decline, (2) initial decline that transitions to a zero-slope plateau, and (3) initial decline followed by later increases in intact proviral DNA. Defective proviral DNA levels were essentially stable. Mechanisms of slowing or reversal of second-phase decay of intact proviral DNA may include the inability to clear cells with intact but transcriptionally silent proviruses and clonal expansion of cells with intact proviruses.

Progressive transformation of the HIV-1 reservoir cell profile over two decades of antiviral therapy

HIV-1 establishes a life-long reservoir of virally infected cells which cannot be eliminated by antiretroviral therapy (ART). Here, we demonstrate a markedly altered viral reservoir profile of long-term ART-treated individuals, characterized by large clones of intact proviruses preferentially integrated in heterochromatin locations, most prominently in centromeric satellite/micro-satellite DNA. Longitudinal evaluations suggested that this specific reservoir configuration results from selection processes that promote the persistence of intact proviruses in repressive chromatin positions, while proviruses in permissive chromosomal locations are more likely to be eliminated. A bias toward chromosomal integration sites in heterochromatin locations was also observed for intact proviruses in study participants who maintained viral control after discontinuation of antiretroviral therapy. Together, these results raise the possibility that antiviral selection mechanisms during long-term ART may induce an HIV-1 reservoir structure with features of deep latency and, possibly, more limited abilities to drive rebound viremia upon treatment interruptions.

Comparative sensitivity of automated (Abbott M2000) and manual plasma HIV-1 RNA PCR assays for the detection of persistent viremia after long-term antiretroviral therapy

Background

The ability of automated, FDA-cleared plasma HIV-1 RNA assays to detect low-level viremia, compared to manual, highly sensitive research-only methods, is not well-defined. We therefore tested paired plasma samples from people with HIV-1 (PWH) on long-term antiretroviral therapy (ART) with both the Abbott M2000 RealTime HIV-1 Viral Load assay (Abbott) and a quantitative reverse transcriptase (RT)-initiated PCR assay that has a reported 95% detection limit of 1 HIV-1 RNA copy/ml (single copy assay, SCA).

Methods

Plasma samples from 309 participants in the AIDS Clinical Trials Group study A5321 were tested by both Abbott and SCA. Participants were mostly men (82%). All were on stable ART for a median of 7 years with HIV-1 RNA <40 copies/mL by Abbott. Pooled plasma from each donor was divided and tested. Abbott results were reported as target detected <40 copies/mL but not quantifiable (target detected <40) or target not detected (TND), and SCA results were classified as HIV-1 RNA detected or not detected.

Results

By Abbott, 17% (51/309) of sample results were target detected <40, whereas 83% (258/309) were TND. Of the samples that were target detected <40 by Abbott, 73% (37/51) had HIV-1 RNA detected by SCA. By contrast, 43% of samples that were TND by Abbott (110/258) had HIV-1 RNA detected by SCA (p < 0.001).

Conclusion

Plasma samples from PWH with HIV-1 RNA detected but <40 copies/ml by the automated Abbott M2000 assay are likely (73% of 51 samples) to have HIV-1 RNA detected by an optimized manual assay with single copy sensitivity. An Abbott HIV-1 RNA result of target not detected did not exclude low-level viremia: 43% of 258 samples had HIV-1 RNA detected by the single copy assay. These findings indicate that the Abbott M2000 assay cannot exclude the persistence of viremia on ART and thus may have less utility, compared to a manual single copy assay, for assessing the impact of experimental interventions designed to eliminate low-level viremia as a step towards achieving ART-free HIV-1 remission.

No evidence that circulating HIV-specific immune responses contribute to persistent inflammation and immune activation in persons on long-term ART

OBJECTIVE

People with HIV (PWH) have persistently elevated levels of inflammation and immune activation despite suppressive antiretroviral therapy (ART), with specific biomarkers showing associations with non-AIDS-defining morbidities and mortality. We investigated the potential role of the HIV-specific adaptive immune response, which also persists under ART, in driving levels of these clinically relevant biomarkers.

DESIGN

Cohort-based study.

METHODS

HIV-specific IFN-γ-producing T-cell responses and antibody concentrations were measured in blood at study entry in the ACTG A5321 cohort, following a median of 7 years of suppressive ART. HIV persistence measures including cell-associated (CA)-DNA, CA-RNA, and plasma HIV RNA (single-copy assay) were also assessed at study entry. Plasma inflammatory biomarkers and T-cell activation and cycling were measured at a pre-ART time point and at study entry.

RESULTS

Neither the magnitudes of HIV-specific T-cell responses nor HIV antibody levels were correlated with levels of the inflammatory or immune activation biomarkers, including hs-CRP, IL-6, neopterin, sCD14, sCD163, TNF-α, %CD38 + HLA-DR + CD8 + and CD4 + cells, and %Ki67 + CD8 + and CD4 + cells - including after adjustment for pre-ART biomarker level. Plasma HIV RNA levels were modestly correlated with CD8 + T-cell activation ( r  = 0.25, P  = 0.027), but other HIV persistence parameters were not associated with these biomarkers. In mediation analysis, relationships between HIV persistence parameters and inflammatory biomarkers were not influenced by either HIV-specific T-cell responses or antibody levels.

CONCLUSION

Adaptive HIV-specific immune responses do not appear to contribute to the elevated inflammatory and immune activation profile in persons on long-term ART.

Prospective Evaluation of Coronavirus Disease 2019 (COVID-19) Vaccine Responses Across a Broad Spectrum of Immunocompromising Conditions: the COVID-19 Vaccination in the Immunocompromised Study (COVICS)

BACKGROUND

We studied humoral responses after coronavirus disease 2019 (COVID-19) vaccination across varying causes of immunodeficiency.

METHODS

Prospective study of fully vaccinated immunocompromised adults (solid organ transplant [SOT], hematologic malignancy, solid cancers, autoimmune conditions, human immunodeficiency virus [HIV]) versus nonimmunocompromised healthcare workers (HCWs). The primary outcome was the proportion with a reactive test (seropositive) for immunoglobulin G to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain. Secondary outcomes were comparisons of antibody levels and their correlation with pseudovirus neutralization titers. Stepwise logistic regression was used to identify factors associated with seropositivity.

RESULTS

A total of 1271 participants enrolled: 1099 immunocompromised and 172 HCW. Compared with HCW (92.4% seropositive), seropositivity was lower among participants with SOT (30.7%), hematological malignancies (50.0%), autoimmune conditions (79.1%), solid tumors (78.7%), and HIV (79.8%) (P < .01). Factors associated with poor seropositivity included age, greater immunosuppression, time since vaccination, anti-CD20 monoclonal antibodies, and vaccination with BNT162b2 (Pfizer) or adenovirus vector vaccines versus messenger RNA (mRNA)-1273 (Moderna). mRNA-1273 was associated with higher antibody levels than BNT162b2 or adenovirus vector vaccines after adjusting for time since vaccination, age, and underlying condition. Antibody levels were strongly correlated with pseudovirus neutralization titers (Spearman r = 0.89, P < .0001), but in seropositive participants with intermediate antibody levels, neutralization titers were significantly lower in immunocompromised individuals versus HCW.

CONCLUSIONS

Antibody responses to COVID-19 vaccines were lowest among SOT and anti-CD20 monoclonal recipients, and recipients of vaccines other than mRNA-1273. Among those with intermediate antibody levels, pseudovirus neutralization titers were lower in immunocompromised patients than HCWs. Additional SARS-CoV-2 preventive approaches are needed for immunocompromised persons, which may need to be tailored to the cause of immunodeficiency.

Associations Between Multiple Measures of HIV-1 Persistence in Persons on Suppressive Antiretroviral Therapy

Clinical research to achieve antiretroviral therapy-free remission requires quantitative assays of the HIV-1 reservoir. Intact proviral DNA (IPD) measurement has greater throughput than the quantitative viral outgrowth assay (QVOA). In 25 individuals with well-documented long-term viral suppression, IPD levels and infectious units per million CD4+ T cells by QVOA strongly correlated (r = 0.59, P = .002), and IPD correlated with total cell-associated HIV-1 DNA and cell-associated HIV-1 RNA (r = 0.62 and r = 0.59, P ≤ .002). IPD may provide an accessible marker of inducible replication-competent virus, total numbers of infected cells, and cellular expression of HIV-1 RNA.

CD4+ T-Cell Dysfunction in Severe COVID-19 Disease Is Tumor Necrosis Factor-α/Tumor Necrosis Factor Receptor 1-Dependent

Rationale: Lymphopenia is common in severe coronavirus disease (COVID-19), yet the immune mechanisms are poorly understood. As inflammatory cytokines are increased in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we hypothesized a role in contributing to reduced T-cell numbers. Objectives: We sought to characterize the functional SARS-CoV-2 T-cell responses in patients with severe versus recovered, mild COVID-19 to determine whether differences were detectable. Methods: Using flow cytometry and single-cell RNA sequence analyses, we assessed SARS-CoV-2-specific responses in our cohort. Measurements and Main Results: In 148 patients with severe COVID-19, we found lymphopenia was associated with worse survival. CD4⁺ lymphopenia predominated, with lower CD4⁺/CD8⁺ ratios in severe COVID-19 compared with patients with mild disease (P < 0.0001). In severe disease, immunodominant CD4⁺ T-cell responses to Spike-1 (S1) produced increased in vitro TNF-α (tumor necrosis factor-α) but demonstrated impaired S1-specific proliferation and increased susceptibility to activation-induced cell death after antigen exposure. CD4⁺TNF-α⁺ T-cell responses inversely correlated with absolute CD4⁺ counts from patients with severe COVID-19 (n = 76; R = -0.797; P < 0.0001). In vitro TNF-α blockade, including infliximab or anti-TNF receptor 1 antibodies, strikingly rescued S1-specific CD4⁺ T-cell proliferation and abrogated S1-specific activation-induced cell death in peripheral blood mononuclear cells from patients with severe COVID-19 (P < 0.001). Single-cell RNA sequencing demonstrated marked downregulation of type-1 cytokines and NFκB signaling in S1-stimulated CD4⁺ cells with infliximab treatment. We also evaluated BAL and lung explant CD4⁺ T cells recovered from patients with severe COVID-19 and observed that lung T cells produced higher TNF-α compared with peripheral blood mononuclear cells. Conclusions: Together, our findings show CD4⁺ dysfunction in severe COVID-19 is TNF-α/TNF receptor 1-dependent through immune mechanisms that may contribute to lymphopenia. TNF-α blockade may be beneficial in severe COVID-19.

Natural Killer Cell Receptors and Ligands Are Associated With Markers of HIV-1 Persistence in Chronically Infected ART Suppressed Patients

The latent HIV-1 reservoir represents a major barrier to achieving a long-term antiretroviral therapy (ART)-free remission or cure for HIV-1. Natural Killer (NK) cells are innate immune cells that play a critical role in controlling viral infections and have been shown to be involved in preventing HIV-1 infection and, in those who are infected, delaying time to progression to AIDS. However, their role in limiting HIV-1 persistence on long term ART is still uncharacterized. To identify associations between markers of HIV-1 persistence and the NK cell receptor-ligand repertoire, we used twin mass cytometry panels to characterize the peripheral blood NK receptor-ligand repertoire in individuals with long-term antiretroviral suppression enrolled in the AIDS Clinical Trial Group A5321 study. At the time of testing, participants had been on ART for a median of 7 years, with virological suppression <50 copies/mL since at most 48 weeks on ART. We found that the NK cell receptor and ligand repertoires did not change across three longitudinal samples over one year-a median of 25 weeks and 50 weeks after the initial sampling. To determine the features of the receptor-ligand repertoire that associate with markers of HIV-1 persistence, we performed a LASSO normalized regression. This analysis revealed that the NK cell ligands CD58, HLA-B, and CRACC, as well as the killer cell immunoglobulin-like receptors (KIRs) KIR2DL1, KIR2DL3, and KIR2DS4 were robustly predictive of markers of HIV-1 persistence, as measured by total HIV-1 cell-associated DNA, HIV-1 cell-associated RNA, and single copy HIV-RNA assays. To characterize the roles of cell populations defined by multiple markers, we augmented the LASSO analysis with FlowSOM clustering. This analysis found that a less mature NK cell phenotype (CD16⁺CD56^dimCD57^-LILRB1^-NKG2C^-) was associated with lower HIV-1 cell associated DNA. Finally, we found that surface expression of HLA-Bw6 measured by CyTOF was associated with lower HIV-1 persistence. Genetic analysis revealed that this was driven by lower HIV-1 persistence in HLA-Bw4/6 heterozygotes. These findings suggest that there may be a role for NK cells in controlling HIV-1 persistence in individuals on long-term ART, which must be corroborated by future studies.

A Phase 1/2 Randomized, Placebo-Controlled Trial of Romidespin in Persons With HIV-1 on Suppressive Antiretroviral Therapy

BACKGROUND

Romidepsin (RMD) is a histone deacetylase inhibitor reported to reverse HIV-1 latency. We sought to identify doses of RMD that were safe and induced HIV-1 expression.

METHODS

Enrollees had HIV-1 RNA <40 copies/mL on antiretroviral therapy. Measurements included RMD levels, plasma viremia by single-copy HIV-1 RNA assay, HIV-1 DNA, cell-associated unspliced HIV-1 RNA (CA-RNA), acetylation of histone H3-lysine-9 (H3K9ac+), and phosphorylation of transcription factor P-TEFb. Wilcoxon tests were used for comparison.

RESULTS

In the single-dose cohorts 1-3, 43 participants enrolled (36 participants 0.5, 2, 5 mg/m 2 RMD; 7 placebo) and 16 enrolled in the multidose cohort 4 (13 participants 5 mg/m 2 RMD; 3 placebo). One grade 3 event (neutropenia) was possibly treatment related. No significant changes in viremia were observed in cohorts 1-4 compared to placebo. In cohort 4, pharmacodynamic effects of RMD were reduced proportions of CD4+ T cells 24 hours after infusions 2-4 (median, -3.5% to -4.5%) vs placebo (median, 0.5% to 1%; P ≤ .022), and increased H3K9ac+ and phosphorylated P-TEFb in CD4 + T cells vs placebo (P ≤ .02).

CONCLUSIONS

RMD infusions were safe but did not increase plasma viremia or unspliced CA-RNA despite pharmacodynamic effects on CD4 + T cells.

CLINICAL TRIALS REGISTRATION

NCT01933594.

Brief Report: Association Between Pain, Pulmonary Function, and Respiratory Symptoms in People With HIV

BACKGROUND

People with HIV (PWH) experience chronic pain and respiratory symptoms, which are closely related in the general population. Pain may affect the impaired pulmonary function seen in PWH beyond its association with HIV alone. Our objective was to investigate the relationship of pain severity to pulmonary function, respiratory symptoms, and sleep disturbance in PWH.

SETTING

Study sites included the University of Pittsburgh, University of California San Francisco, and University of Washington.

METHODS

Pain, dyspnea, and sleep were assessed using the Brief Chronic Pain Questionnaire, St. George's Respiratory Questionnaire, and Pittsburgh Sleep Quality Index. Participants performed prebronchodilator and postbronchodilator spirometry and 6-minute walk test. Associations between pain severity, lung function, dyspnea, and sleep were assessed with bivariate and multiple quantile regression analysis adjusted for age, sex, race, body mass index, and smoking status.

RESULTS

Of 159 PWH, the median age was 56 years with 30.8% women. Two-thirds experienced pain in the past week, with 40.3% reporting chronic pain. Pain severity was higher with female sex (P = 0.038), non-White race (P = 0.005), current smoking (P = 0.003), and lower CD4+ count (P = 0.035). In adjusted analysis, higher pain severity was correlated with reduced postbronchodilator forced expiratory volume in 1 second %predicted (P = 0.008), reduced postbronchodilator forced vital capacity %predicted (P = 0.019), and chronic obstructive pulmonary disease (P = 0.032). Greater pain severity was strongly associated with a higher St. George's Respiratory Questionnaire score (P < 0.001) and sleep disturbance (P < 0.001).

CONCLUSIONS

In PWH, pain is common and associated with airflow obstruction, dyspnea, and sleep disturbance. Future studies assessing pain severity and pulmonary function over time could clarify the direction of this association and the impact on quality of life.

Comparison of methods to quantify inducible HIV-1 outgrowth

The quantitative viral outgrowth assay (qVOA) is the gold standard for measuring inducible, replication-competent HIV-1. Using MOLT4-R5 and SupT1-R5 cell lines instead of allogeneic blasts and HIV-1 RNA detection rather than p24 enzyme-immunoassay (EIA) has been proposed to improve the sensitivity of the qVOA. It is unclear, however, how these alternative approaches affect qVOA performance. We compared three qVOAs methods across 15 persons with HIV-1 on suppressive antiretroviral therapy and found that the MOLT4-R5 method yielded a significantly higher proportion of p24-positive wells (42%) than both the allogeneic blast (29%) and SupT1-R5 (32%) assays. Additionally, 5 of 7 qVOAs that were negative by p24 EIA showed viral outgrowth by HIV-1 RNA quantification (>10-fold increase within 7 days). These findings reveal the potential for underestimation of the latent, inducible reservoir by qVOA depending on the target cells used and the measure of viral outgrowth. Use of MOLT4-R5 cells with both p24 EIA and HIV-1 RNA to detect viral outgrowth was the most sensitive method.

Association of Male Sex and Obesity With Residual Plasma Human Immunodeficiency Virus 1 Viremia in Persons on Long-Term Antiretroviral Therapy

BACKGROUND

Although adipose tissue has been proposed to harbor part of the human immunodeficiency virus 1 (HIV-1) reservoir, the influence of host characteristics, including sex and body mass index (BMI), on measures of HIV-1 persistence during antiretroviral therapy (ART) are incompletely understood.

METHODS

We evaluated age, sex, BMI, waist circumference, years on ART, pre-ART HIV-1 RNA, pre-ART CD4+ T-cell count, and initial ART regimen with measures of HIV-1 persistence in blood (residual viremia, cellular HIV-1 DNA and RNA) in a cohort of 295 individuals with well-documented long-term virologic suppression (HIV-1 RNA <50 copies/mL) on ART (AIDS Clinical Trials Group study A5321).

RESULTS

Men were more likely than women to have detectable plasma HIV-1 RNA by single-copy assay (52% vs 29%; P = .003), and the proportion of participants with detectable residual viremia increased in a stepwise fashion by BMI category (normal weight or underweight, 38%; overweight, 50%; and obese, 55%). ART regimen type was not associated with measures of HIV-1 persistence after controlling for ART duration.

CONCLUSIONS

Sex and obesity are independently associated with residual viremia in people on long-term ART. Additional studies to confirm these relationships and to define the mechanisms by which sex and obesity affect HIV-1 persistence are needed to inform HIV-1 cure strategies.

HIV-specific T cell responses reflect substantive in vivo interactions with antigen despite long-term therapy

Antiretroviral therapies (ARTs) abrogate HIV replication; however, infection persists as long-lived reservoirs of infected cells with integrated proviruses, which reseed replication if ART is interrupted. A central tenet of our current understanding of this persistence is that infected cells are shielded from immune recognition and elimination through a lack of antigen expression from proviruses. Efforts to cure HIV infection have therefore focused on reactivating latent proviruses to enable immune-mediated clearance, but these have yet to succeed in reducing viral reservoirs. Here, we revisited the question of whether HIV reservoirs are predominately immunologically silent from a new angle: by querying the dynamics of HIV-specific T cell responses over long-term ART for evidence of ongoing recognition of HIV-infected cells. In longitudinal assessments, we show that the rates of change in persisting HIV Nef-specific responses, but not responses to other HIV gene products, were associated with residual frequencies of infected cells. These Nef-specific responses were highly stable over time and disproportionately exhibited a cytotoxic, effector functional profile, indicative of recent in vivo recognition of HIV antigens. These results indicate substantial visibility of the HIV-infected cells to T cells on stable ART, presenting both opportunities and challenges for the development of therapeutic approaches to curing infection.

Selective Decay of Intact HIV-1 Proviral DNA on Antiretroviral Therapy

BACKGROUND

HIV-1 proviruses persist in people on antiretroviral therapy (ART) but most are defective and do not constitute a replication-competent reservoir. The decay of infected cells carrying intact compared with defective HIV-1 proviruses has not been well defined in people on ART.

METHODS

We separately quantified intact and defective proviruses, residual plasma viremia, and markers of inflammation and activation in people on long-term ART.

RESULTS

Among 40 participants tested longitudinally from a median of 7.1 years to 12 years after ART initiation, intact provirus levels declined significantly over time (median half-life, 7.1 years; 95% confidence interval [CI], 3.9-18), whereas defective provirus levels did not decrease. The median half-life of total HIV-1 DNA was 41.6 years (95% CI, 13.6-75). The proportion of all proviruses that were intact diminished over time on ART, from about 10% at the first on-ART time point to about 5% at the last. Intact provirus levels on ART correlated with total HIV-1 DNA and residual plasma viremia, but there was no evidence for associations between intact provirus levels and inflammation or immune activation.

CONCLUSIONS

Cells containing intact, replication-competent proviruses are selectively lost during suppressive ART. Defining the mechanisms involved should inform strategies to accelerate HIV-1 reservoir depletion.

Naive CD4+ T Cells Harbor a Large Inducible Reservoir of Latent, Replication-competent Human Immunodeficiency Virus Type 1

BACKGROUND

The latent human immunodeficiency virus type 1 (HIV-1) reservoir represents a major barrier to a cure. Based on the levels of HIV-1 DNA in naive (TN) vs resting memory CD4+ T cells, it is widely hypothesized that this reservoir resides primarily within memory cells. Here, we compared virus production from TN and central memory (TCM) CD4+ T cells isolated from HIV-1-infected individuals on suppressive therapy.

METHODS

CD4+ TN and TCM cells were purified from the blood of 7 HIV-1-infected individuals. We quantified total HIV-1 DNA in the CD4+ TN and TCM cells. Extracellular virion-associated HIV-1 RNA or viral outgrowth assays were used to assess latency reversal following treatment with anti-CD3/CD28 monoclonal antibodies (mAbs), phytohaemagglutinin/interleukin-2, phorbol 12-myristate 13-acetate/ionomycin, prostratin, panobinostat, or romidepsin.

RESULTS

HIV-1 DNA was significantly higher in TCM compared to TN cells (2179 vs 684 copies/106 cells, respectively). Following exposure to anti-CD3/CD28 mAbs, virion-associated HIV-1 RNA levels were similar between TCM and TN cells (15 135 vs 18 290 copies/mL, respectively). In 4/7 donors, virus production was higher for TN cells independent of the latency reversing agent used. Replication-competent virus was recovered from both TN and TCM cells.

CONCLUSIONS

Although the frequency of HIV-1 infection is lower in TN compared to TCM cells, as much virus is produced from the TN population after latency reversal. This finding suggests that quantifying HIV-1 DNA alone may not predict the size of the inducible latent reservoir and that TN cells may be an important reservoir of latent HIV-1.

ABCG2 Deficiency Does Not Alter Dolutegravir Metabolism and Pharmacokinetics

Dolutegravir (DTG) is a potent integrase inhibitor of human immunodeficiency virus. Because DTG is a substrate of the efflux transporter ABCG2 and ABCG2 is highly polymorphic, we asked whether dose adjustment of DTG is needed for ABCG2-deficient individuals. Using Abcg2-null mice, the current work investigated the impact of ABCG2 deficiency on DTG metabolism and pharmacokinetics. Compared with wild-type mice, no statistically significant difference was found in the systemic and tissue-specific (liver, kidney, and brain) pharmacokinetics of DTG in Abcg2-null mice. In addition, ABCG2 deficiency had no statistically significant impact on the production and excretion of DTG metabolites. In summary, this study demonstrated that deficiency of ABCG2 does not alter DTG metabolism and pharmacokinetics, suggesting that dose adjustment of DTG is not needed for individuals with ABCG2 deficiency. SIGNIFICANCE STATEMENT: The current work demonstrated that deficiency of ATP-binding cassette subfamily G member 2 (ABCG2) does not alter Dolutegravir (DTG) metabolism and pharmacokinetics, suggesting that dose adjustment of DTG is not needed for individuals with ABCG2 deficiency.

The North-South Divide: Substance Use Risk, Care Engagement, and Viral Suppression Among Hospitalized Human Immunodeficiency Virus-Infected Patients in 11 US Cities

Regional variability in human immunodeficiency virus (HIV) care engagement remains underexplored. Multiple logistic models compared HIV outcomes for participants from 5 Southern (n = 557) and 6 non-Southern (n = 670) sites. Southern participants were less likely to experience viral suppression (adjusted odds ratio [aOR], 0.52; 95% confidence interval [CI], .37-.72) and had a higher likelihood of a CD4+ count <200 cells/µL (aOR, 1.53; 95% CI, 1.17-2.00). HIV intervention and social safety net programs should be expanded.

Clinical Trials Registration

NCT01612169.

Allogeneic Hematopoietic Cell Transplant for HIV Patients with Hematologic Malignancies: The BMT CTN-0903/AMC-080 Trial

We set out to assess feasibility and safety of allogeneic hematopoietic cell transplant in 17 persons with HIV in a phase II prospective multicenter trial. The primary endpoint was 100-day nonrelapse mortality (NRM). Patients had an 8/8 HLA-matched related or at least a 7/8 HLA-matched unrelated donor. Indications for transplant were acute leukemia, myelodysplasia, and lymphoma. Conditioning was myeloablative or reduced intensity. There was no NRM at 100 days. The cumulative incidence of grades II to IV acute graft-versus-host disease (GVHD) was 41%. At 1 year, overall survival was 59%; deaths were from relapsed/progressive disease (n = 5), acute GVHD (n = 1), adult respiratory distress syndrome (n = 1), and liver failure (n = 1). In patients who achieved complete chimerism, cell-associated HIV DNA and inducible infectious virus in the blood were not detectable. Blood and Marrow Transplant Clinical Trials Network 0903/AIDS Malignancy Consortium 080 was registered at www.clinicaltrials.gov (no. NCT01410344).

Cumulative Antiretroviral Exposure Measured in Hair Is Not Associated With Measures of HIV Persistence or Inflammation Among Individuals on Suppressive ART

Data on the relationship of antiretroviral exposure to measures of human immunodeficiency virus (HIV) persistence are limited. To address this gap, multiple viral, immunologic, and pharmacologic measures were analyzed from individuals with sustained virologic suppression on therapy (median 7 years) in the AIDS Clinical Trials Group A5321 cohort. Among 110 participants on tenofovir-(TFV)-disoproxil-fumarate (TDF)/emtricitabine (FTC)-containing regimens, we found no significant correlation between hair concentrations of individual antiretrovirals (ARVs) in the regimen and measures of HIV persistence (plasma HIV-1 RNA by single copy assay, cell-associated-DNA, cell-associated RNA) or soluble markers of inflammation. These findings suggest that higher systemic ARV exposure may not impact HIV persistence or inflammation.

T-cell responses targeting HIV Nef uniquely correlate with infected cell frequencies after long-term antiretroviral therapy

HIV-specific CD8+ T-cell responses limit viral replication in untreated infection. After the initiation of antiretroviral therapy (ART), these responses decay and the infected cell population that remains is commonly considered to be invisible to T-cells. We hypothesized that HIV antigen recognition may persist in ART-treated individuals due to low-level or episodic protein expression. We posited that if persistent recognition were occurring it would be preferentially directed against the early HIV gene products Nef, Tat, and Rev as compared to late gene products, such as Gag, Pol, and Env, which have higher barriers to expression. Using a primary cell model of latency, we observed that a Nef-specific CD8+ T-cell clone exhibited low-level recognition of infected cells prior to reactivation and robust recognition shortly thereafter. A Gag-specific CD8+ T-cell clone failed to recognized infected cells under these conditions, corresponding with a lack of detectable Gag expression. We measured HIV-specific T-cell responses in 96 individuals who had been suppressed on ART for a median of 7 years, and observed a significant, direct correlation between cell-associated HIV DNA levels and magnitudes of IFN-γ-producing Nef/Tat/Rev-specific T-cell responses. This correlation was confirmed in an independent cohort (n = 18). Correlations were not detected between measures of HIV persistence and T-cell responses to other HIV antigens. The correlation with Nef/Tat/Rev-specific T-cells was attributable to Nef-specific responses, the breadth of which also correlated with HIV DNA levels. These results suggest that ongoing Nef expression in ART-treated individuals drives preferential maintenance and/or expansion of T-cells reactive to this protein, implying sensing of infected cells by the immune system. The direct correlation, however, suggests that recognition does not result in efficient elimination of infected cells. These results raise the possibility that enhancing the cytolytic activity of Nef-specific T-cells may lead to reductions in infected cell frequencies, even in the absence of therapeutic latency reversal.

Effect of Patient Navigation With or Without Financial Incentives on Viral Suppression Among Hospitalized Patients With HIV Infection and Substance Use: A Randomized Clinical Trial

IMPORTANCE

Substance use is a major driver of the HIV epidemic and is associated with poor HIV care outcomes. Patient navigation (care coordination with case management) and the use of financial incentives for achieving predetermined outcomes are interventions increasingly promoted to engage patients in substance use disorders treatment and HIV care, but there is little evidence for their efficacy in improving HIV-1 viral suppression rates.

OBJECTIVE

To assess the effect of a structured patient navigation intervention with or without financial incentives to improve HIV-1 viral suppression rates among patients with elevated HIV-1 viral loads and substance use recruited as hospital inpatients.

DESIGN, SETTING, AND PARTICIPANTS

From July 2012 through January 2014, 801 patients with HIV infection and substance use from 11 hospitals across the United States were randomly assigned to receive patient navigation alone (n = 266), patient navigation plus financial incentives (n = 271), or treatment as usual (n = 264). HIV-1 plasma viral load was measured at baseline and at 6 and 12 months.

INTERVENTIONS

Patient navigation included up to 11 sessions of care coordination with case management and motivational interviewing techniques over 6 months. Financial incentives (up to $1160) were provided for achieving targeted behaviors aimed at reducing substance use, increasing engagement in HIV care, and improving HIV outcomes. Treatment as usual was the standard practice at each hospital for linking hospitalized patients to outpatient HIV care and substance use disorders treatment.

MAIN OUTCOMES AND MEASURES

The primary outcome was HIV viral suppression (≤200 copies/mL) relative to viral nonsuppression or death at the 12-month follow-up.

RESULTS

Of 801 patients randomized, 261 (32.6%) were women (mean [SD] age, 44.6 years [10.0 years]). There were no differences in rates of HIV viral suppression versus nonsuppression or death among the 3 groups at 12 months. Eighty-five of 249 patients (34.1%) in the usual-treatment group experienced treatment success compared with 89 of 249 patients (35.7%) in the navigation-only group for a treatment difference of 1.6% (95% CI, -6.8% to 10.0%; P = .80) and compared with 98 of 254 patients (38.6%) in the navigation-plus-incentives group for a treatment difference of 4.5% (95% CI -4.0% to 12.8%; P = .68). The treatment difference between the navigation-only and the navigation-plus-incentives group was -2.8% (95% CI, -11.3% to 5.6%; P = .68).

CONCLUSIONS AND RELEVANCE

Among hospitalized patients with HIV infection and substance use, patient navigation with or without financial incentives did not have a beneficial effect on HIV viral suppression relative to nonsuppression or death at 12 months vs treatment as usual. These findings do not support these interventions in this setting.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01612169.

HIV-1 DNA decay dynamics in blood during more than a decade of suppressive antiretroviral therapy

BACKGROUND

Human immunodeficiency virus type 1 (HIV-1) DNA dynamics during long-term antiretroviral therapy (ART) are not defined.

METHODS

Blood mononuclear cells obtained during 7-12 years of effective ART were assayed for total HIV-1 DNA and 2-long terminal repeat (LTR) circles by quantitative polymerase chain reaction (qPCR). Slopes of HIV-1 DNA were estimated by participant-specific linear regressions. Plasma was assayed for residual viremia (HIV-1 RNA) by qPCR.

RESULTS

Thirty participants were studied. HIV-1 DNA decreased significantly from years 0-1 and 1-4 of ART with median decay slopes of -0.86 (interquartile range, -1.05, -0.59) and -0.11 (-0.17, -0.06) log10(copies/10(6) CD4+ T-cells)/year, respectively (P < .001). Decay was not significant for years 4-7 (-0.02 [-0.06, 0.02]; P = .09) or after year 7 of ART (-0.006 [-0.030, 0.015]; P = .17). All participants had detectable HIV-1 DNA after 10 years (median 439 copies/10(6) CD4+ T-cells; range: 7-2074). Pre-ART HIV-1 DNA levels were positively associated with pre-ART HIV-1 RNA levels (Spearman = 0.71, P < .001) and with HIV-1 DNA at years 4, 7, and 10 on ART (Spearman ≥ 0.75, P < .001). No associations were found (P ≥ .25) between HIV-1 DNA slopes or levels and % activated CD8+ T-cells (average during years 1-4) or residual viremia (n = 18). 2-LTR circles were detected pre-ART in 20/29 and in 8/30 participants at last follow-up.

CONCLUSIONS

Decay of HIV-1 DNA in blood is rapid in the first year after ART initiation (86% decline), slows during years 1-4 (23% decline/year), and subsequently plateaus. HIV-1 DNA decay is not associated with the levels of CD8+ T-cell activation or persistent viremia. The determinants of stable HIV-1 DNA persistence require further elucidation. Clinical Trials Registration. NCT00001137.

Contributors to diffusion impairment in HIV-infected persons

Abnormal diffusing capacity is common in HIV-infected individuals, including never smokers. Aetiologies for diffusing capacity impairment in HIV are not understood, particularly in those without a history of cigarette smoking. Our study was a cross-sectional analysis of 158 HIV-infected individuals without acute respiratory symptoms or infection with the aim to determine associations between a diffusing capacity of the lung for carbon monoxide (D(LCO)) % predicted and participant demographics, pulmonary spirometric measures (forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity), radiographic emphysema (fraction of lung voxels < -950 Hounsfield units), pulmonary vascular/cardiovascular disease (echocardiographic tricuspid regurgitant jet velocity, N-terminal pro-brain natriuretic peptide) and airway inflammation (induced sputum cell counts), stratified by history of smoking. The mean D(LCO) was 65.9% predicted, and 55 (34.8%) participants had a significantly reduced D(LCO) (<60% predicted). Lower D(LCO) % predicted in ever-smokers was associated with lower post-bronchodilator FEV1 % predicted (p<0.001) and greater radiographic emphysema (p=0.001). In never-smokers, mean±SD D(LCO) was 72.7±13.4% predicted, and D(LCO) correlated with post-bronchodilator FEV1 (p=0.02), sputum neutrophils (p=0.03) and sputum lymphocytes (p=0.009), but not radiographic emphysema. Airway obstruction, emphysema and inflammation influence D(LCO) in HIV. Never-smokers may have a unique phenotype of diffusing capacity impairment. The interaction of multiple factors may account for the pervasive nature of diffusing capacity impairment in HIV infection.

Greater suppression of nevirapine resistance with 21- vs 7-day antiretroviral regimens after intrapartum single-dose nevirapine for prevention of mother-to-child transmission of HIV

BACKGROUND

Nevirapine (NVP) resistance emerges in up to 70% of women exposed to single-dose (sd) NVP for prevention of mother-to-child transmission of human immunodeficiency virus (HIV).

METHODS

HIV-infected pregnant women were randomized to receive sdNVP and either zidovudine/lamivudine (3TC), tenofovir/emtricitabine (FTC), or lopinavir/ritonavir for either 7 or 21 days. The primary endpoint was the emergence of new NVP resistance mutations as detected by standard population genotype at 2 and 6 weeks after treatment. Low-frequency NVP- or 3TC/FTC-resistant mutants at codons 103, 181, and 184 were sought using allele-specific polymerase chain reaction (ASP).

RESULTS

Among 484 women randomized, 422 (87%) received study treatment. Four hundred twelve (98%) women had primary endpoint results available; of these, 5 (1.2%) had new NVP resistance detected by population genotype: 4 of 215 in the 7-day arms (1.9%; K103N in 4 women with Y181C, Y188C, or G190A in 3 of 4) and 1 of 197 (0.5%; V108I) in the 21-day arms (P = .37). Among women with ASP results, new NVP resistance mutations emerged significantly more often in the 7-day arms (13/74 [18%]) than in the 21-day arms (3/66 [5%], P = .019). 3TC/FTC-resistant mutants (M184V/I) emerged infrequently (7/134 [5%]), and their occurrence did not differ by arm.

CONCLUSIONS

Three short-term antiretroviral strategies, begun simultaneously with the administration of sdNVP, resulted in a low rate (1.2%) of new NVP-resistance mutations when assessed at 2 and 6 weeks following completion of study treatment by standard genotype. ASP revealed that 21-day regimens were significantly better than 7-day regimens at preventing the emergence of minor NVP resistance variants. Clinical Trials Registration.NCT00099632.

Asthma diagnosis and airway bronchodilator response in HIV-infected patients

BACKGROUND

Despite the high prevalence of respiratory symptoms and obstructive lung disease in HIV-infected subjects, the prevalence of bronchodilator reversibility (BDR) and asthma has not been systematically studied during the era of combination antiretroviral therapy (ART).

OBJECTIVE

We sought to determine the prevalence of asthma diagnosis and related pulmonary function abnormalities in an HIV-infected cohort and to identify potential mechanisms.

METHODS

We performed a cross-sectional analysis of 223 HIV-infected subjects with data on respiratory symptoms and diagnoses, pulmonary function, sputum cell counts, and asthma-related cytokines and chemokines in serum/sputum.

RESULTS

Doctor-diagnosed asthma was present in 46 (20.6%), and BDR (≥200 mL and ≥12% increase in FEV(1) or forced vital capacity) was present in 20 (9.0%) participants. Pulmonary symptoms and function were worse in those with doctor-diagnosed asthma. Doctor-diagnosed asthma was independently associated with female sex (P = .04), body mass index of greater than 29.6 kg/m(2) (vs <29.6 kg/m(2), P = .03), history of bacterial or Pneumocystis pneumonia (P = .01), and not currently taking ART (P = .04) and in univariate analysis with parental history of asthma (n = 180, P = .004). High sputum eosinophil percentages (>2.3% based on the highest decile) were more likely in those with doctor-diagnosed asthma (P = .02) or BDR (P = .02). Doctor-diagnosed asthma tended to be more common with high sputum IL-4 (P = .02) and RANTES (P = .02) levels, whereas BDR was associated with high plasma macrophage inflammatory protein 1α (P = .002) and sputum macrophage inflammatory protein 1β (P = .001) levels.

CONCLUSION

Asthma diagnosis and BDR are prevalent in an HIV-infected outpatient cohort, and associations with family history, obesity, allergic inflammation, prior infection, absence of ART, and increased HIV-stimulated cytokines suggest possible mechanisms of HIV-associated asthma.

Pulmonary function abnormalities in HIV-infected patients during the current antiretroviral therapy era

RATIONALE

Before the introduction of combination antiretroviral (ARV) therapy, patients infected with HIV had an increased prevalence of respiratory symptoms and lung function abnormalities. The prevalence and exact phenotype of pulmonary abnormalities in the current era are unknown. In addition, these abnormalities may be underdiagnosed.

OBJECTIVES

Our objective was to determine the current burden of respiratory symptoms, pulmonary function abnormalities, and associated risk factors in individuals infected with HIV.

METHODS

Cross-sectional analysis of 167 participants infected with HIV who underwent pulmonary function testing.

MEASUREMENTS AND MAIN RESULTS

Respiratory symptoms were present in 47.3% of participants and associated with intravenous drug use (odds ratio [OR] 3.64; 95% confidence interval [CI], 1.32-10.046; P = 0.01). Only 15% had previous pulmonary testing. Pulmonary function abnormalities were common with 64.1% of participants having diffusion impairment and 21% having irreversible airway obstruction. Diffusion impairment was independently associated with ever smoking (OR 2.46; 95% CI, 1.16-5.21; P = 0.02) and Pneumocystis pneumonia prophylaxis (OR 2.94; 95% CI, 1.10-7.86; P = 0.01), whereas irreversible airway obstruction was independently associated with pack-years smoked (OR 1.03 per pack-year; 95% CI, 1.01-1.05; P < 0.01), intravenous drug use (OR 2.87; 95% CI, 1.15-7.09; P = 0.02), and the use of ARV therapy (OR 6.22; 95% CI, 1.19-32.43; P = 0.03).

CONCLUSIONS

Respiratory symptoms and pulmonary function abnormalities remain common in individuals infected with HIV. Smoking and intravenous drug use are still important risk factors for pulmonary abnormalities, but ARV may be a novel risk factor for irreversible airway obstruction. Obstructive lung disease is likely underdiagnosed in this population.

Recovery of replication-competent HIV type 1-infected circulating monocytes from individuals receiving antiretroviral therapy

The affect of antiretroviral therapy (ART) on HIV-1 recovery from blood monocytes was determined in purified peripheral blood monocyte-derived macrophage (MDM) cultures from HIV-1-infected subjects with undetectable plasma viremia or active viral replication. Additionally, the association between replication-competent HIV-1-infected MDM and neurocognitive status was examined. Fifty-two individual with previous AIDS-defining illnesses receiving nucleoside analogues with and without protease inhibitors or no ART were followed for up to 1.5 years. Detection of plasma viremia significantly correlated with the occurrence of infected monocytes. Viral replication was detected in less than 10% of the MDM cultures from 23 individuals receiving effective antiretroviral therapy. In contrast, approximately 50% of the MDM cultures from 29 individuals with active viral replication and evidence of decreased immune function, including all individuals with neurocognitive impairment, produced detectable virus indicating that a lack of adequate ART results in increased abundance of replication-competent blood monocytes. Proviral DNA levels were a minimum of 13-fold higher in MDM from subjects with active viral replication. The infrequent detection of viral DNA in cultures from individuals receiving effective ART suggested low levels of circulating monocytes harboring replication-incompetent virus. These studies demonstrate that HIV-infected individuals on ART with breakthrough viremia have significantly higher levels of circulating infected monocytes, the precursors of tissue macrophages.

Leukocyte-reduced red blood cell transfusions in patients with anemia and human immunodeficiency virus infection: the Viral Activation Transfusion Study: a randomized controlled trial

CONTEXT

Allogeneic blood transfusions have immunomodulatory effects and have been associated with activation of human immunodeficiency virus (HIV) and cytomegalovirus (CMV) in vitro and of HIV in small pilot studies. Retrospective studies suggest that transfusions adversely affect the clinical course of HIV. Data in selected non-HIV-infected patients requiring blood transfusion have suggested clinical benefit with leukocyte-reduced red blood cells (RBCs).

OBJECTIVE

To compare the effects of leukoreduced and unmodified RBC transfusions on survival, complications of acquired immunodeficiency syndrome, and relevant laboratory markers in HIV-infected patients.

DESIGN AND SETTING

Double-blind randomized controlled trial conducted in 11 US academic medical centers from July 1995 through June 1999, with a median follow-up of 12 months (24 months in survivors).

PATIENTS

A total of 531 persons infected with HIV and CMV, aged 14 years or older, who required transfusions for anemia; 259 received leukoreduced transfusions and 262 received unmodified transfusions (10 did not receive the planned transfusion).

MAIN OUTCOME MEASURES

Survival and change in plasma HIV RNA level 7 days after transfusion, compared by type of transfusion.

RESULTS

At entry, the groups were similar in demographic, clinical, and relevant laboratory characteristics. A total of 3864 RBC units were transfused. Two hundred eighty-nine deaths occurred (151 with leukoreduced transfusion; 138 with unmodified transfusion); median survival was 13.0 and 20.5 months, respectively (relative hazard [RH], 1.20; 95% confidence interval [CI], 0.95-1.51; log-rank P =.12). Analyses adjusted for prognostic factors suggested possible worse survival with leukoreduction (RH, 1.35; 95% CI, 1.06-1.72). There was no difference in time to new opportunistic event/death or frequency of transfusion reactions. No changes in plasma HIV RNA level were seen in either group at days 7, 14, 21, or 28, even in patients not taking antiretroviral drugs. There were no differences in trends between groups in CMV DNA, CD4 cell counts, activated (CD38% or human leukocyte antigen-DR) CD8 cell counts, or plasma cytokine levels.

CONCLUSIONS

We found no evidence of HIV, CMV, or cytokine activation following blood transfusion in patients with advanced HIV infection. Leukoreduction provided no clinical benefit in these patients. These data demonstrate the importance of conducting controlled studies of effects of leukoreduction in different patient populations, since smaller studies in other patient populations have suggested leukoreduction may be beneficial.

Anti-human immunodeficiency virus type 1 (HIV-1) CD8(+) T-lymphocyte reactivity during combination antiretroviral therapy in HIV-1-infected patients with advanced immunodeficiency

The long-term efficacy of combination antiretroviral therapy may relate to augmentation of anti-human immunodeficiency virus type 1 (HIV-1) CD8(+) T-cell responses. We found that prolonged treatment of late-stage HIV-1-infected patients with a protease inhibitor and two nucleoside reverse transcriptase inhibitors failed to restore sustained, high levels of HIV-1-specific, HLA class I-restricted, cytotoxic-T-lymphocyte precursors and gamma interferon (IFN-gamma) production by CD8(+) T cells. In some patients, particularly those initiating three-drug combination therapy simultaneously rather than sequentially, there were early, transient increases in the frequency of anti-HIV-1 CD8(+) T cells that correlated with decreases in HIV-1 RNA and increases in T-cell counts. In the other patients, HIV-1-specific T-cell functions either failed to increase or declined from baseline during triple-drug therapy, even though some of these patients showed suppression of plasma HIV-1 RNA. These effects of combination therapy were not unique to HIV-1 specific T-cell responses, since similar effects were noted for CD8(+) T cells specific for the cytomegalovirus pp65 matrix protein. The level and breadth of CD8(+) cell reactivity to HLA A*02 HIV-1 epitopes, as determined by IFN-gamma production and HLA tetramer staining after combination therapy, were related to the corresponding responses prior to treatment. There was, however, a stable, residual population of potentially immunocompetent HIV-1-specific T cells remaining after therapy, as shown by tetramer staining of CD8(+) CD45RO(+) cells. These results indicate that new strategies will be needed to target residual, immunocompetent HIV-1-specific CD8(+) T cells to enhance the effectiveness of antiretroviral therapy in patients with advanced immunodeficiency.

Prolonged suppression of human immunodeficiency virus type 1 (HIV-1) viremia in persons with advanced disease results in enhancement of CD4 T cell reactivity to microbial antigens but not to HIV-1 antigens

CD4 T cell responses were studied for >2 years in 27 zidovudine-experienced patients with advanced human immunodeficiency virus type 1 (HIV-1) infection who received triple combination drug therapy with indinavir, zidovudine and lamivudine or zidovudine plus lamivudine or zidovudine alone for 24-42 weeks before switching to the three-drug therapy. Subjects initially given the three drugs had viremia suppressed to undetectable levels and increases in T cell proliferative and cytokine responses to microbial antigens through 2 years of follow-up. Patients receiving the triple-drug therapy after either indinavir or zidovudine-lamivudine treatment had similar increases in T cell responses only if they also had suppression of virus load. CD4 T cell reactivity to HIV-1 antigens was not restored. Prolonged indinavir-zidovudine-lamivudine treatment has significant but incomplete enhancing effects on CD4 T cell reactivity, which could be important in host control of microbial and persistent HIV-1 infections.

Safety and pharmacokinetics of 5-chloro-2',3'-dideoxy-3'-fluorouridine (935U83) following oral administration of escalating single doses in human immunodeficiency virus-infected adults

5-Chloro-2',3'-dideoxy-3'-fluorouridine (935U83) is a nucleoside analog reverse transcriptase inhibitor that has demonstrated selective anti-human immunodeficiency virus (HIV) activity in vitro and favorable safety profiles in monkeys and mice. A phase I study was conducted to evaluate the safety and pharmacokinetics of six escalating single oral doses of 935U83 in 12 HIV-infected adults. The effect of a high-fat meal on the oral bioavailability of 935U83 was also assessed. The volunteers enrolled had CD4+ cell counts ranging from < 50 to 753 cells per mm3 (median, 198). In the dose range of 100 to 1,500 mg 935U83 was well tolerated by all subjects with no drug-related adverse events reported. No significant clinical or laboratory abnormalities were observed throughout the study. 935U83 was rapidly and well absorbed following oral administration with peak plasma concentrations (Cmax) occurring at 0.8 to 1.3 h postdosing. Mean Cmax and AUC0-infinity values of 935U83 were nearly dose proportional in the 100- to 1,500-mg dose range (from 2.4 to 30 micrograms/ml and from 3.4 to 59 h.micrograms/ml, respectively). Elimination of 935U83 from the plasma was rapid, with an apparent half-life of 1.3 to 1.7 h which was independent of the dose level. Administration of 935U83 with a high-fat meal decreased the rate of 935U83 absorption (mean Cmax decreased by approximately 50% and mean time to Cmax increased by approximately 1 h) but did not affect the extent of oral bioavailability (AUC0-infinity) of 935U83. The 5'-O-glucuronide conjugate was the principal metabolite of 935U83 and was present in the plasma of all volunteers at concentrations lower than 935U83. The molar AUC0-infinity ratio (935U83 glucuronide to the parent compound) was similar across all dose levels (mean, 21 to 27%). At least 60% of the 935U83 dose was absorbed, and approximately an equal percentage of the dose (approximately 30%) was excreted as unchanged 935U83 and as 935U83 glucuronide. Systemic exposure to 935U83 at levels exceeding its average in vitro antiretroviral 50% inhibitory concentration (approximately 0.5 microgram/ml or 1.8 microM) can be achieved after a single oral dose.

Preservation of hemostatic and structural properties of rehydrated lyophilized platelets: potential for long-term storage of dried platelets for transfusion

Currently, therapeutic platelet concentrates can be stored for only 5 days. We have developed a procedure that permits long-term storage of fixed and lyophilized platelets that retain hemostatic properties after rehydration. These rehydrated lyophilized platelets (RL platelets) restore hemostasis in thrombocytopenic rats and become incorporated in the hemostatic plug of bleeding time wounds of normal dogs as well as von Willebrand disease dogs with partially replenished plasma von Willebrand factor. Ultrastructurally, these platelets are well preserved and are comparable to control normal washed platelets. Flow cytometry analysis shows that RL platelets react with antibodies to the major surface receptors, glycoprotein (GP)Ib and GPIIb/IIIa. These receptors are involved in platelet agglutination, aggregation, and adhesion. In vitro functional tests document the ability of RL platelets to adhere to denuded subendothelium and to spread on a foreign surface. Circulating RL platelets participated in carotid arterial thrombus formation induced in normal canine subjects. The participation of RL platelets in these vital hemostatic properties suggests that with further development they could become a stable platelet product for transfusion.

C2C12 cells: biophysical, biochemical, and immunocytochemical properties

We examined the myofibril biochemical, structural, and biophysical properties of C2C12, a mouse skeletal muscle cell line (American Type Culture Collection), to assess whether force development and the sensitivity of the myofilaments to calcium could be measured in C2C12 myotubes and whether a cardiac contractile protein, troponin T, is expressed and incorporated into C2C12 myofibrils. When myoblasts fused and differentiated into myotubes, expression of myofilament proteins was initiated. Multiple cardiac and skeletal muscle troponin T isoforms were coexpressed. Cardiac troponin T expression increased and then decreased with time. Fluorescence immunocytochemistry demonstrated incorporation of cardiac troponin T isoforms into the myofibrils. At the time of the biophysical studies, mean myotube diameter was 12 microns (range 5-25 microns), and mean length was 290 microns (range 130-520 microns). The estimated maximum force developed by chemically skinned myotubes at 6-7 days poststarvation, 0.88 +/- 0.12 microN (mean +/- 95% confidence interval, n = 5), was significantly less (P < 0.05) than that at 10-13 days poststarvation, 1.12 +/- 0.12 microN (n = 7). The force-pCa relation yielded a Hill coefficient of 2.9 +/- 0.6 (n = 7) and half-maximal activation at pCa of 5.77 +/- 0.20. The demonstration that the biophysical properties of C2C12 cells can be measured and that cardiac and skeletal muscle troponin T isoforms are incorporated and colocalized into myofibrils suggest that these cells could be a useful model to assess the effects of exogenous native and mutated cardiac and skeletal contractile protein isoforms on myofilament function.

A phase I study of subcutaneous recombinant interleukin-2 in patients with advanced HIV disease while on zidovudine

OBJECTIVE

A Phase I study of subcutaneous recombinant interleukin-2 (rIL-2).

DESIGN

Sixteen patients with advanced HIV infection receiving 600-1200 mg zidovudine per day were divided into three groups, which received sequentially 0.2 x 10(6), 0.7 x 10(6) or 2 x 10(6) units/m2 per day of rIL-2 subcutaneously 5 consecutive days.

SETTING

Five-day admission to an academic tertiary care hospital.

PATIENTS, PARTICIPANTS

Sixteen unblinded, non-randomized volunteers.

INTERVENTIONS

Subcutaneous rIL-2.

MAIN OUTCOME MEASURES

Tolerance, toxicity, hematologic, immunologic and antiviral responses.

RESULTS

rIL-2 was well-tolerated at the highest dosage, except in two patients who developed significant lymphopenia by the second day of rIL-2 administration, with rebound within 48 h after rIL-2 therapy. The number of eosinophils, CD4+ and CD8+ cells, and percentage of CD16+ (natural killer) cells, remained elevated above baseline for up to 10 weeks. Circulating rIL-2 receptor levels increased transiently during and immediately following rIL-2 administration. A twofold increase in natural killer cell activity against uninfected and HIV-infected targets was observed, but did not persist beyond 10 weeks following rIL-2 administration. There was a transient decrease in blastogenesis to phytohemagglutinin of patients receiving the highest dose of r-IL-2, but no significant change in viral burden.

CONCLUSIONS

Subcutaneous rIL-2 in advanced HIV-infected patients on zidovudine was tolerated with side-effects similar to intravenous IL-2.

A two-motif isoform of the major calcium channel subunit in skeletal muscle

Evidence is presented that two isoforms of the voltage-dependent, dihydropyridine-sensitive calcium channel alpha 1 subunit are present in newborn and adult skeletal muscle and that expression of these isoforms is developmentally regulated. A voltage-dependent calcium channel alpha 1 cDNA from newborn muscle was cloned and found to be identical to that published from the adult, except that it was 2 kb shorter owing to an internal deletion. Nucleotide sequences, Northern blots, reverse-transcriptase PCR experiments, and sequencing of the PCR product confirmed that a segment corresponding to the inner two repeats of the structural prototype four homologous motifs is missing from the immature isoform. Immunological studies using antisera raised against synthetic peptides that correspond to sequences in the two isoforms show that the abbreviated transcript is predominant in newborn muscle, whereas the four-repeat isoform is the major species in the adult.

Zidovudine therapy is associated with an increased capacity of phytohemagglutinin-stimulated cells to express interleukin-2 receptors. Pittsburgh AIDS Clinical Trial Unit

Zidovudine therapy of AIDS patients has been shown to cause only transient improvements in the numbers of circulating CD4+ cells and the in vitro functional activities of cultured lymphocytes. The present studies were undertaken to determine whether prolonged zidovudine therapy enhanced reactivity in two sensitive assays of T-cell function: the ability of phytohemagglutinin (PHA)-stimulated cells to form T-cell colonies and their capacity to express receptors for the growth factor interleukin-2 (IL-2). Treated patients, studied over periods of 20-60 weeks, showed no improvement in colony formation at any time interval, even in plates supplemented with exogenous IL-2. However, mitogen-stimulated T lymphocytes showed a significant increase in the capacity to express IL-2 receptors (CD25). This enhanced expression resulted primarily from activation of the CD8+ cell subset.

Extragenital Mycoplasma hominis infections in adults

PURPOSE

To heighten awareness of the role of Mycoplasma hominis as an extragenital pathogen in adults.

PATIENTS AND METHODS AND RESULTS

Patients ranged in age from 14 to 76 years. Thirteen patients were immunosuppressed, including nine organ transplant recipients; three were receiving steroids, and two had an underlying malignancy. The remainder were immunocompetent. Thirteen patients had prior surgery at or near the site of infection. M. hominis was isolated from normally sterile sites such as blood or cerebrospinal, pleural, abdominal and joint fluids, and bone. Non-sterile sites of isolation included surgical wounds and pulmonary secretions. The organism was detected in anaerobic cultures of clinical specimens sent to the laboratory for routine bacteriologic culture. Gram stains of fluids or wound drainage revealed neutrophils but no bacteria. Anti-mycoplasmal therapy was effective in eradicating the organism in 13 of 15 patients who were treated. Of those in whom treatment failed, one patient had an antibiotic-resistant isolate and the other had M. hominis isolated from the lung at postmortem after just 2 days of therapy.

CONCLUSION

Our experience suggests that significant infections due to M. hominis, although uncommon, are not rare, and methods to isolate and identify this organism should be available for general adult medical and surgical populations.