985. Impact of Age and Medical Comorbidities on Renal Outcomes in the DISCOVER Trial

Background

In DISCOVER, emtricitabine/tenofovir alafenamide (F/TAF) was noninferior to F/tenofovir disoproxil fumarate (TDF) for preexposure prophylaxis (PrEP) in men who have sex with men and transgender women, with a superior renal laboratory profile. The differential impact of F/TAF and F/TDF on renal parameters among older individuals and those with medical comorbidities is unknown.

Methods

DISCOVER randomized participants 1:1 to daily blinded F/TAF or F/TDF. We examined renal outcomes at week 48 including estimated glomerular filtration rate (eGFR) by Cockcroft-Gault, β2 microglobulin (M):Creatinine (Cr) and retinol binding protein (RBP):Cr ratios (markers of proximal renal tubular function), and discontinuations due to investigator reported study drug-related renal adverse events (AEs).

Results

Median age was 34 years (yrs)(range 18-76), with 12.5% vs 10.9% < 25yrs, 12.2% vs 14.4% ≥ 50yrs, and 1.1% vs 0.9% > 65yrs for F/TAF and F/TDF, respectively. The prevalence of medical comorbidities at baseline were; eGFR < 90mL/min= 9.1% vs 9.3%, diabetes= 2.9% vs 3.3%, and hypertension= 10.5 vs 11.1%, for F/TAF and F/TDF, respectively. eGFR changes by age category and medical comorbidity status are found in the Table. Forty participants had study drug-related renal AEs; 14 with F/TAF and 26 with F/TDF. Of these, 25% were > 50yrs, 20% had baseline eGFR < 90mL/min, 7.5% had history of diabetes, and 22.5% had history of hypertension. β2M:Cr and RBP:Cr changes were more favorable in participants receiving F/TAF, with greater magnitude of difference in older participants (data not shown).

Table.

Conclusion

The DISCOVER trial allows for a large single variable comparison of the two tenofovir prodrugs in the absence of underlying HIV infection and in the absence of third antiretroviral agents. F/TAF was associated with favorable changes in renal biomarkers regardless of age or medical comorbidity. Participants ≥50yrs or with comorbidities were proportionately more likely to develop study drug related renal AEs, but these were present in the minority of cases.

Disclosures

Eric Daar, MD, BMS (Consultant)Gilead Sciences Inc. (Consultant, Grant/Research Support, Scientific Research Study Investigator)Janssen (Consultant)Merck (Consultant, Grant/Research Support)Teva (Consultant)Theratechnology (Consultant)Viiv Healthcare (Consultant, Grant/Research Support) Jason Brunetta, MD, AbbVie (Consultant)Gilead Sciences Inc. (Consultant, Grant/Research Support, Scientific Research Study Investigator, Speaker’s Bureau, Other Financial or Material Support, Conference attendance sponsorship)Janssen (Other Financial or Material Support, Conference attendance sponsorship)Merck (Consultant, Speaker’s Bureau, Other Financial or Material Support, Conference attendance sponsorship)Viiv Healthcare (Consultant, Speaker’s Bureau, Other Financial or Material Support, Conference attendance sponsorship) Eric Cua, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) David Asmuth, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Yongwu Shao, PhD, Gilead Sciences Inc. (Employee, Shareholder) Pamela Wong, MPH, Gilead Sciences Inc. (Employee, Shareholder) Ramin Ebrahimi, MSc, Gilead Sciences Inc. (Employee, Shareholder) Moupali Das, MD, Gilead Sciences Inc. (Employee, Shareholder) Diana M. Brainard, MD, Gilead Sciences (Employee) Amanda Clarke, MD, Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Other Financial or Material Support, Conference attendance sponsorship)Viiv Healthcare (Consultant, Other Financial or Material Support, Conference travel sponsorship)

1002. A Daily Single Tablet Regimen (STR) of Bictegravir/Emtricitabine/Tenofovir Alafenamide (B/F/TAF) in Virologically-Suppressed Adults Living with HIV and End Stage Renal Disease on Chronic Hemodialysis

Background

Treatment for people living with HIV (PLWH) and end stage renal disease (ESRD) on hemodialysis (HD) has previously required complex dose-adjusted regimens. We evaluated a daily regimen of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) and established this treatment as effective and safe, showing that daily TAF resulted in lower plasma tenofovir exposure than a historical comparison of once weekly tenofovir disoproxil fumarate in patients with ESRD on HD. After week (W) 96, participants transitioned to daily B/F/TAF to assess whether efficacy and safety would be maintained on this STR that is guidelines-recommended for PLWH with eGFR > 30 mL/min.

Methods

Virologically suppressed adult PLWH with ESRD on chronic HD who completed W96 on E/C/F/TAF enrolled in the B/F/TAF extension for 48 weeks. Efficacy was assessed as the proportion of participants with virologic suppression (HIV RNA < 50 copies/mL). Safety was assessed throughout the study, PK was assessed using sparse sampling at W4, 24 and 48.

Results

55 enrolled, 36 completed E/C/F/TAF, 10 entered the B/F/TAF extension. The median age was 55 yrs (range 34-63); median time on HD was 4 yrs (range 2-16). All ten participants on B/F/TAF had HIV-1 RNA < 50 c/mL (95% CI 69%, 100%) at W48. All participants had at least 1 adverse event (AE); most were grade 1 or 2 in severity. One participant had a grade 3 AE and 3 had serious AEs; none were considered related to study drug by the investigator. One participant had AEs attributed to study drug (malaise grade 1 and nausea grade 2), which resolved and did not lead to discontinuation of study drug. There were no clinically relevant changes in fasting lipids. In participants with evaluable data (n=2-5 per timepoint), mean bictegravir trough concentrations were lower compared to PLWH not on HD but remained 4- to 7-fold higher than the established protein-adjusted 95% effective concentration (paEC₉₅) of 162 ng/mL against wild-type virus.

Conclusion

A once daily regimen of B/F/TAF maintained virologic suppression in PLWH on chronic HD. B/F/TAF was well-tolerated with no discontinuations. B/F/TAF may be an effective, safe and convenient once daily STR and ameliorate the need for dose adjustment in appropriate PLWH who require chronic HD.

Disclosures

Joseph J. Eron, MD, Gilead Sciences (Consultant, Research Grant or Support)Janssen (Consultant, Research Grant or Support)Merck (Consultant)ViiV Healthcare (Consultant, Research Grant or Support) Aimee Wilkin, MD, MPH, Gilead Sciences Inc. (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member)GlaxoSmithKline (Grant/Research Support)Janssen (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member)Pfizer (Grant/Research Support) Moti Ramgopal, MD FACP FIDSA, AbbVie (Speaker’s Bureau)Allergan (Speaker’s Bureau)Gilead Sciences Inc. (Consultant, Scientific Research Study Investigator, Speaker’s Bureau)Janssen (Speaker’s Bureau)Merck (Consultant)Viiv Healthcare (Consultant) Olayemi Osiyemi, M.D, GlaxoSmithKline (Advisor or Review Panel member, Speaker’s Bureau)ViiV Healthcare (Advisor or Review Panel member, Speaker’s Bureau) Jihad Slim, MD, Abbvie (Speaker’s Bureau)Gilead (Speaker’s Bureau)Jansen (Speaker’s Bureau)Merck (Speaker’s Bureau)ViiV (Speaker’s Bureau) David Asmuth, MD, Gilead Sciences Inc. (Scientific Research Study Investigator) Edwin DeJesus, MD, Gilead Sciences (Advisor or Review Panel member) Polina German, PharmD, Gilead Sciences (Employee) Christiana Blair, MS, Gilead Sciences (Employee, Shareholder) Christoph C. Carter, MD, Gilead Sciences Inc. (Employee, Shareholder) Diana M. Brainard, MD, Gilead Sciences (Employee) Sean E. Collins, MD, MS, Gilead Sciences (Employee) Hal Martin, MD, MPH, Gilead Sciences Inc. (Employee, Shareholder)

Re-boost immunizations with the peptide-based therapeutic HIV vaccine, Vacc-4x, restores geometric mean viral load set-point during treatment interruption

Background

Vacc-4x, a therapeutic HIV vaccine candidate has previously induced a significant reduction in viral load (VL) set-point compared to placebo upon interruption of combination anti-retroviral therapy (ART) (2007/1 study). This study, (2012/1), explored the potential to maintain Vacc-4x effect by re-boosting eligible 2007/1 study participants.

Methods

Participant inclusion required 2007/1 participants to have completed all Vacc-4x immunizations and interrupted ART for up to 26 weeks. At weeks (wk)0 and 2, participants received intradermal (i.d.) Vacc-4x booster immunizations (1.2mg) on ART with GM-CSF (60μg) i.d. as a local adjuvant. ART was interrupted for up to 16 weeks (wk12-wk28). Participants were then followed on ART until wk36. VL set-point, total proviral DNA (pvDNA) and immunogenicity assessed by IFN-γ ELISPOT, T-cell proliferation and delayed type hypersensitivity (DTH) reactions were compared to participants’ values in the 2007/1 study where available.

Results

This open, multicenter, clinical study enrolled 33 participants from 9 clinical trial sites in the US and Europe. In the per-protocol (PP) population, the VL set-point geometric mean (GM) 18162 copies/mL was not significantly changed compared to the 2007/1 study (GM VL 22035 copies/mL), (p = 0.453, n = 18). For participants with available preART VL values, the VL set-point (GM 26279 copies/mL) remained significantly lower than the preART VL set-point (GM 74048 copies/mL, p = 0.021, n = 13). A statistically significant reduction in pvDNA (49%) from baseline to wk4 was observed (p = 0.03, n = 26). DTH responses (wk4) increased significantly from baseline (p = 0.006, n = 30) and compared to the 2007/1 study (p = 0.022, n = 29) whilst the proportion of participants with ELISPOT and T-cell proliferation responses was similar between the two studies.

Conclusions

Vacc-4x booster immunizations safely maintained the mean VL set-point at that established following primary Vacc-4x therapeutic immunization. The reduction in pvDNA during ART supports the potential for Vacc-4x immunization to reduce HIV reservoirs and thereby contribute to combination HIV cure strategies.

Continued Elevation of Interleukin-18 and Interferon-γ After Initiation of Antiretroviral Therapy and Clinical Failure in a Diverse Multicountry Human Immunodeficiency Virus Cohort

Background. We assessed immune activation after antiretroviral therapy (ART) initiation to understand clinical failure in diverse settings.

Methods. We performed a case-control study in ACTG Prospective Evaluation of Antiretrovirals in Resource-Limited Settings (PEARLS). Cases were defined as incident World Health Organization Stage 3 or 4 human immunodeficiency virus (HIV) disease or death, analyzed from ART weeks 24 (ART24) to 96. Controls were randomly selected. Interleukin (IL)-6, interferon (IFN)-γ-inducible protein-10, IL-18, tumor necrosis factor-α, IFN-γ, and soluble CD14 (sCD14) were measured pre-ART and at ART24 in plasma. Continued elevation was defined by thresholds set by highest pre-ART quartiles (>Q3). Incident risk ratios (IRRs) for clinical progression were estimated by Poisson regression, adjusting for age, sex, treatment, country, time-updated CD4⁺ T-cell count, HIV ribonucleic acid (RNA), and prevalent tuberculosis.

Results. Among 99 cases and 234 controls, median baseline CD4⁺ T-cell count was 181 cells/µL, and HIV RNA was 5.05 log₁₀ cp/mL. Clinical failure was independently associated with continued elevations of IL-18 (IRR, 3.03; 95% confidence interval [CI], 1.27–7.20), sCD14 (IRR, 2.17; 95% CI, 1.02–4.62), and IFN-γ (IRR, 0.08; 95% CI, 0.01–0.61). Among 276 of 333 (83%) who were virologically suppressed at ART24, IFN-γ was associated with protection from failure, but the association with sCD14 was attenuated.

Conclusions. Continued IL-18 and sCD14 elevations were associated with clinical ART failure. Interferon-γ levels may reflect preserved immune function.

Serum-derived bovine immunoglobulin increases peripheral and mucosal CD4 T cell count (MUC8P.736)

A multi-center trial in HIV-enteropathy was conducted to evaluate the impact of serum-derived bovine immunoglobulin (SBI) on markers of peripheral and mucosal immunity as previously reported. Participants (pts) with HIV enteropathy were randomized to SBI 2.5 vs 5.0 g BID or placebo (PBO) during a 4-wk lead-in phase followed by SBI 2.5 vs 5.0 g BID for 20 wks. 103 pts were enrolled with a mean duration of HIV, ART, and enteropathy over 15, 5 and 5 years, respectively. While there was no evidence for a median change in peripheral CD4 counts in all pts from baseline to wk 24 (681 to 661 cells/mL), significant increases were observed among pts in the lowest quartile (n=24)(311 to 366 cells/mL, p=0.002). In this subgroup the SBI pts had increased CD4 counts at wk 4 vs PBO pts (median +42 vs ‑16 cells/mL, p=0.02) which was maintained through wk 24. The mean plasma zonulin levels increased from 358(±317) to 812(±423) ng/mL (p&lt;0.001) for pts receiving SBI through 24 weeks. Duodenal CD4 densities increased from 217 to 329 cells/mm2 (median increase of 145 cells/mm2 [p=0.02]) in biopsies obtained from 8 pts, confirming earlier findings. Duodenal crypt cells expressing Ki67 decreased in 6/7 pts from 41% to 24% (p=0.08) which correlated with the decreased number of Paneth cells per crypt (p=0.048). SBI may be a novel therapy to restore mucosal immunity and impact systemic immune reconstitution among pts who have not achieved normal CD4 counts despite prolonged suppressive ART.

Sofosbuvir and ribavirin for hepatitis C in patients with HIV coinfection

IMPORTANCE

Treatment of hepatitis C virus (HCV) infection in patients also infected with human immunodeficiency virus (HIV) has been limited due to drug interactions with antiretroviral therapies (ARTs) and the need to use interferon.

OBJECTIVE

To determine the rates of HCV eradication (sustained virologic response [SVR]) and adverse events in patients with HCV-HIV coinfection receiving sofosbuvir and ribavirin treatment.

DESIGN, SETTING, AND PARTICIPANTS

Open-label, nonrandomized, uncontrolled phase 3 trial conducted at 34 treatment centers in the United States and Puerto Rico (August 2012-November 2013) evaluating treatment with sofosbuvir and ribavirin among patients with HCV genotypes 1, 2, or 3 and concurrent HIV. Patients were required to be receiving ART with HIV RNA values of 50 copies/mL or less and a CD4 T-cell count of more than 200 cells/μL or to have untreated HIV infection with a CD4 T-cell count of more than 500 cells/μL. Of the treatment-naive patients, 114 had HCV genotype 1 and 68 had HCV genotype 2 or 3, and 41 treatment experienced participants who had been treated with peginterferon-ribavirin had HCV genotype 2 or 3, for a total of 223 participants.

INTERVENTIONS

Treatment-naive patients with HCV genotype 2 or 3 received 400 mg of sofosbuvir and weight-based ribavirin for 12 weeks and treatment-naive patients with HCV genotype 1 and treatment-experienced patients with HCV genotype 2 or 3 received the same treatment for 24 weeks.

MAIN OUTCOMES AND MEASURES

The primary study outcome was the proportion of patients with SVR (serum HCV <25 copies/mL) 12 weeks (SVR12) after cessation of HCV therapy.

RESULTS

Among treatment-naive participants, 87 patients (76%) of 114 (95% CI, 67%-84%) with genotype 1, 23 patients (88%) of 26 with genotype 2 (95% CI, 70%-985), and 28 patients (67%) of 42 with genotype 3 (95% CI, 51%-80%) achieved SVR12. Among treatment-experienced participants, 22 patients (92%) of 24 with genotype 2 (95% CI, 73%-99%) and 16 patients (94%) of 17 (95% CI, 71%-100%) achieved SVR12. The most common adverse events were fatigue, insomnia, headache, and nausea. Seven patients (3%) discontinued HCV treatment due to adverse events. No adverse effect on HIV disease or its treatment was observed.

CONCLUSIONS AND RELEVANCE

In this open-label, nonrandomized, uncontrolled study, patients with HIV who were coinfected with HCV genotype 1, 2, or 3 who received the oral, interferon-free combination of sofosbuvir and ribavirin for 12 or 24 weeks had high rates of SVR12. Further studies of this oral regimen in diverse populations of coinfected patients are warranted.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01667731.

Impact of highly active antiretroviral therapy on hepatitis C virus protease quasispecies diversity in HIV co-infected patients

Many hepatitis C virus (HCV)-infected patients are also infected with HIV, and undergo antiretroviral (ARV) treatment for their human immunodeficiency virus (HIV) infection. Due to changes in HIV burden and immunologic status, HIV ARV treatment may have indirect effects on the HCV population, which could impact the effectiveness of subsequent HCV protease inhibitor (PI) treatment. The genetic variability of the protease-encoding HCV NS3 gene was evaluated in 10 co-infected patients initiating ARVs (both before and after ARV initiation), and compared to the genetic variability in 10 patients on stable ARV therapy. After RT-PCR of plasma-derived HCV RNA, a mean of 20 clones per patient time-point were sequenced and analyzed for changes in the HCV quasispecies population. No significant differences in sequence diversity or complexity at the nucleic acid or amino acid levels were seen at baseline between groups or between the two time points in either group. HCV protease diversity in the pre- and post-ARV treatment samples was not significantly different than samples from patients on stable ARV therapy. There was no significant development of amino acid substitutions known to confer HCV PI resistance in either group. Initiation of ARV for HIV infection does not significantly alter the genetic diversity or complexity of the HCV NS3 gene or result in increased number of HCV PI-associated amino acid changes. These results suggest ARV treatment for HIV would not affect the efficacy of HCV PI treatment.

Lowering the dose of hydroxyurea minimizes toxicity and maximizes anti-HIV potency

The goal of this study was to optimize the hydroxyurea dosage in HIV-infected patients, and to minimize the toxicity and maximize the antiviral efficacy of the hydroxyurea-didanosine combination. In a randomized, open-label study (RIGHT 702, a multicenter trial performed in private and institutional practices), three daily doses (600 microg, 800-900 microg, and 1200 microg) of hydroxyurea were administered in combination with didanosine and stavudine to 115 chronically HIV-infected patients, one-third antiretroviral drug naive, with viremia between 5000 and 200,000 copies/ml regardless of CD4+ cell count. The primary efficacy end point was the proportion of patients with plasma HIV-1 RNA levels below 400 copies/ml after 24 weeks of therapy. In the RIGHT 702 intent-to-treat population the lowest (600 mg) dose of hydroxyurea was better tolerated, associated with fewer adverse events, and more potent by all efficacy parameters, including the primary end point (76 versus 60% patients with viremia<400 copies/ml at week 24 for the 600-mg and 800- to 900-mg dose groups, respectively; p=0.027), the mean area under the curve (60.3 versus 65.8; p=0.016), and the mean log10 decrease (-1.95 versus -0.77; p=0.001). Patients receiving 600 mg of hydroxyurea daily also had the highest CD4+ cell count, CD4+/CD8+ cell ratio, and lowest CD8+ cell count and percentage (p=0.035). The RIGHT 702 trial provides an explanation for the increased toxicity and decreased efficacy of hydroxyurea when it was used at high dosage (1200 mg daily). At the optimal dosage of 600 mg daily, hydroxyurea, in combination with didanosine, deserves reevaluation for the long-term management of HIV/AIDS worldwide, because of its excellent resistance profile, durability, and affordability.

Entrapment of recent thymic emigrants in lymphoid tissues from HIV-infected patients: association with HIV cellular viral load

OBJECTIVE(S)

Depletion of thymus derived naive T-cells is a feature of HIV infection. Here the impact of HIV infection on the compartmentalization of recent thymic emigrants of (RTE) and naive T-cells was examined.

METHODS

Peripheral blood mononuclear cells (PBMC) and lymphoid tissue (LT) from 43 HIV-infected patients and 12 controls were examined for RTE distribution by measuring coding joint T-cell receptor excisional circles (cjTREC) by PCR and naive and memory T-cell subsets and adhesion molecules (L-selection, LFA-1) by flow cytometry.

RESULTS

In HIV-infected patients, the RTE as quantified by cjTRECs in CD4 LT cells were significantly higher than in PBMC. Their values, however, were less than in control subjects, in both the LT and PBMC compartments. This was associated with an increase in L-selectin and LFA-1 expression on LT derived T cells. In PBMC, a significant positive relationship between TREC and naive CD4 cells and an inverse relationship between TREC and cellular viral load (CVL) was observed. Whereas in LT, there was a positive relationship between cjTREC and both naive CD4 cell percentage and CVL.

CONCLUSIONS

Collectively, the data suggests that LT is a significant reservoir for RTE. The RTE appeared to be entrapped in LT from HIV-infected subjects. Such entrapment is probably a response to the high viral load in these tissues. These observations may partially explain the decline in RTE observed in the peripheral blood of HIV-infected patients, and the delay in recovery of naive cells in blood after initiation of HAART.

Homeostasis of naive and memory T cell subpopulations in peripheral blood and lymphoid tissues in the context of human immunodeficiency virus infection

To understand the nature of naive and memory T cell depletion in human immunodeficiency virus (HIV) immunopathogenesis, their homeostasis in peripheral blood (PB) and lymph node (LN) compartments of HIV-infected patients was examined. Although the percentage of naive CD4+ cells was higher in LN than in PB mononuclear cells (LNMC and PBMC, respectively), the memory cells were higher in PBMC than in LNMC. The ratio of naive:memory CD4+ cells from PB positively correlated with that in LNs and with the absolute CD4+ cell counts and recall antigen responses, and the ratio inversely correlated with the cellular virus load from the corresponding compartment. These findings indicate that although the pattern of naive and memory cells in the LN and PB compartments appear divergent, their relationship is nonrandom and is significant. The naive&rcolon;memory ratio in PB appears to reflect the lymphoid microenvironment and may potentially be useful as a surrogate marker for treatment efficacy and immune reconstitution.

Chemokine/CD4 receptor density ratios correlate with HIV replication in lymph node and peripheral blood of HIV-infected individuals

OBJECTIVES

Lymphoid tissue is a major reservoir for virus replication in HIV-infected subjects. The relationship of CCR5 and CXCR4 coreceptor density and HIV replication in peripheral blood mononuclear cells (PBMC) and lymph node (LN) mononuclear cells (LNMC) of HIV-infected subjects was examined.

METHODS

PBMC and cervical LNMC from 12 HIV-infected patients were examined for virological and immunological parameters including chemokine receptor density, HIV plasma and cellular viral load, coreceptor usage and CD38/HLA-DR expression.

RESULTS

The number of CCR5 and CXCR4 molecules on CD4 lymphocytes in the LN were significantly higher than in PBMC. In contrast the number of CD4 molecules/CD4 T cell was higher in PBMC than in LNMC. The CXCR4/CD4 and CCR5/CD4 ratios in the LN were significantly higher than in the PBMC. This was associated with a cellular viral load in the LN that was approximately 110-fold higher than in PBMC. The absolute number of coreceptor molecules per cell did not correlate with the viral load. However, the CCR5/CD4 and CXCR4/CD4 ratios in the LN positively correlated with HIV cellular and plasma RNA. Characterization of the viral isolates suggested an association between clinical isolates using a distinct coreceptor and the upregulation of the corresponding chemokine receptor.

CONCLUSIONS

The ratios of chemokine receptors to CD4 molecules in CD4 T cells from LN is higher than in PBMC and may account for the relative difference in cellular viral load in these compartments. Additionally, the coreceptor/CD4 ratios, particularly in the lymphoid tissue, were highly related to HIV replication.

'Modeling' relationships among HIV-1 replication, immune activation and CD4+ T-cell losses using adjusted correlative analyses

OBJECTIVE

To model the relationships among HIV-1 replication, immune activation and CD4+ T-cell losses in HIV-1 infection.

METHODS

Cross-sectional analysis of baseline data from the Viral Activation by Transfusion Study. Comparisons of unadjusted and adjusted correlative analyses to establish models for mechanisms of cell loss in AIDS.

RESULTS

Using these analyses, significant correlations were found among plasma levels of tumor necrosis factor alpha (TNFalpha) and its type two receptor (TNFrII), interleukin-6 (IL-6), beta2-microglobulin, expression of CD38 and HLA-DR on CD8+ T lymphocytes and plasma levels of HIV-1 RNA. When correlations among these indices were adjusted for possible intermediary correlations, the relationship between HIV-1 RNA levels and all plasma markers of immune activation could be accounted for by the correlation between plasma HIV-1 RNA and plasma TNFrII levels. In addition, the negative correlations that both HIV-1 RNA levels and TNFrII levels had with CD4+ T-cell counts were partially accounted for by the correlations of HIV-1 RNA and TNFrII with CD38 expression on CD8+ T cells. In persons with advanced disease (CD4+ T cells < 50 x 10(6)/l) IL-6 levels were inversely correlated with CD4+ T-cell counts.

CONCLUSIONS

This analysis is consistent with a model wherein HIV-1 replication induces TNFalpha expression that induces multiple other indices of immune activation. In this model, HIV-1 replication and TNFalpha expression induce CD4+ T-cell losses at least in part through mechanisms reflected in heightened CD38 expression.

Diagnosis of intestinal microsporidiosis by examination of stool and duodenal aspirate with Weber's modified trichrome and Uvitex 2B strains

Severe, chronic diarrhea is a frequent complication of human immunodeficiency virus disease, and intestinal microsporidiosis is being recognized with increasing frequency in patients with AIDS. Noninvasive, cost-effective techniques are needed to optimize its diagnosis. Weber's modified trichrome stain (MTS) and the fluorochrome Uvitex 2B stain were used to detect microsporidial spores in smears of stool and duodenal aspirate (DA) samples received from human immunodeficiency virus-infected patients for examination for ova and parasites. Of 305 samples (292 stool and 13 DA samples) from 140 patients examined by MTS, 83 samples from 26 (18.6%) of the patients were positive for microsporidia (23 patients diagnosed initially and 3 diagnosed upon review). A subset of the samples studied by MTS consisting of 108 smears of stool and DA specimens from 60 patients was examined by Uvitex 2B. All 44 samples positive by MTS were also positive by Uvitex 2B. In addition, seven specimens and three patients were initially detected as positive by Uvitex 2B only (all three patients were positive also by MTS upon review). Confirmation of the diagnosis was obtained for 24 of 26 smear-positive patients by duodenal biopsy and/or stool transmission electron microscopy. Of 114 patients with stained smears negative for microsporidia, 23 had duodenal biopsies which showed no microsporidia. For the 43 patients who underwent duodenal biopsy, the sensitivity of both the MTS and the Uvitex 2B methods compared with biopsy results was 100%. Of six patients with negative duodenal biopsies and positive stained smears, four had microsporidia demonstrated by stool transmission electron microscopy. The examination of stool and DA smears stained by Uvitex 2B and/or MTS is a sensitive, noninvasive test for diagnosis of intestinal microsporidiosis which can be successfully implemented in a clinical laboratory. Strict adherence to precise diagnostic criteria is necessary to avoid incorrect results. The simultaneous use of both staining methods enhances performance and may provide greater accuracy, especially for patients with light infections.