Antiretroviral treatment for adult HIV infection in 2002: updated recommendations of the International AIDS Society-USA Panel

OBJECTIVE

New information warrants updated recommendations for the 4 central issues in antiretroviral therapy: when to start, what drugs to start with, when to change, and what to change to. These updated recommendations are intended to guide practicing physicians actively involved in human immunodeficiency virus (HIV)- and acquired immunodeficiency syndrome (AIDS)-related care.

PARTICIPANTS

In 1995, physicians with specific expertise in HIV-related basic science and clinical research, antiretroviral therapy, and HIV patient care were invited by the International AIDS Society-USA to serve on a volunteer panel. In 1999, others were invited to broaden international representation. The 17-member panel met regularly in closed meetings between its last report in 2000 and April 2002 to review current data. The effort was sponsored and funded by the International AIDS Society-USA, a not-for-profit physician education organization.

EVIDENCE AND CONSENSUS PROCESS

The full panel was convened in late 2000 and assigned 7 section committees. A section writer and 3 to 5 section committee members (each panel member served on numerous sections) identified relevant evidence and prepared draft recommendations. Basic science, clinical research, and epidemiologic data from the published literature and abstracts from recent (within 2 years) scientific conferences were considered by strength of evidence. Extrapolations from basic science data and expert opinion of the panel members were included as evidence. Draft sections were combined and circulated to the entire panel and discussed in a series of full-panel conference calls until consensus was reached. Final recommendations represent full consensus agreement of the panel.

CONCLUSIONS

Because of increased awareness of the activity and toxicity of current drugs, the threshold for initiation of therapy has shifted to a later time in the course of HIV disease. However, the optimal time to initiate therapy remains imprecisely defined. Availability of new drugs has broadened options for therapy initiation and management of treatment failure, which remains a difficult challenge.

Maternal HIV-1 antibody and vertical transmission in subtype C virus infection

The role of maternal humoral immune response and viral load was analyzed in relation to the incidence of mother-to-child transmission (MTCT) of infants born to HIV-1 subtype C infected mothers. High levels of viral RNA in the serum correlated with MTCT as did high titers of subtype C consensus V3 peptide binding antibodies (BA) and neutralizing antibody (NA) to subtype B HIV-1MN. Logistic regression analysis showed that maternal viral load and V3 peptide subtype C BA were independent predictors for MTCT, odds ratio (OR) = 2.22 and OR = 2.52, respectively. No correlation between NA to homologous HIV-1 subtype C virus and MTCT was found. BA to V3 peptides may provide a rapid inexpensive method that can be used to determine the risk of HIV-1 MTCT.

Severity of HIV-associated neuropathy is associated with plasma HIV-1 RNA levels

OBJECTIVE

To determine if there is an association between plasma HIV-1 RNA levels and severity of HIV-associated distal symmetrical polyneuropathy (DSP).

DESIGN

Substudy of AIDS Clinical Trials Group Protocol 291, a double-blind, placebo-controlled study of recombinant human nerve growth factor for the treatment of painful DSP.

METHODS

Two-hundred and thirty-six subjects had plasma HIV-1 RNA load assayed at baseline. Mean and maximum neuropathic pain was assessed once daily by the Gracely Pain Scale. Other measures included subjects' global pain assessment and quantitative sensory tests (QST). These values were correlated with baseline HIV-1 RNA levels.

RESULTS

Among 168 subjects with detectable plasma HIV-1 RNA, there was a significant correlation between plasma HIV-1 RNA and the severity of maximum and global pain, and toe cooling thresholds. Maximum and global pain assessment correlated with plasma HIV-1 RNA in individuals with detectable viral load (r, 0.162 and 0.194; P = 0.04 and 0.01, respectively).

CONCLUSIONS

There is an association between plasma HIV-1 RNA levels and the severity of pain and QST results in HIV-associated DSP. Further studies are needed to determine if aggressive use of antiretroviral drugs, including the use of dideoxynucleosides, may be of benefit to prevent or improve peripheral neuropathy.

Characterization of the HIV-1 specific humoral immune response during highly active antiretroviral therapy (HAART)

Plasma samples from 19 patients were analyzed for HIV-1 directed humoral immune responses prior to and 1 year after initiation of HAART. Eight of the subjects were classified as virologic successes, defined by a >100-fold decrease in viral load (VL) over the 1-year study period and a final VL <500 copies/ml. The eleven HAART failures were defined as subjects with <10-fold decrease in VL. At study entry (before HAART), VL and CD4 counts were similar between the two groups. Humoral immune responses before therapy and after 1 year of therapy were measured by V3 peptide antibody binding titers and neutralization of HIV-1 MN and four subtype B clinical isolates. Before HAART, neutralizing antibody titers to the clinical isolates and HIV(MN), as well as HIV V3 envelope binding titers to several V3 peptides, were significantly higher among treatment successes compared with treatment failures. After 1 year on HAART, neutralization declined in titer and narrowed in specificity among the HAART successes. In contrast, a significant increase in both neutralizing titer and breadth was seen among HAART failures.

Associations of CCR5, CCR2, and stromal cell-derived factor 1 genotypes with human immunodeficiency virus disease progression in patients receiving nucleoside therapy

Genotype data for CCR5, CCR2, and stromal cell-derived factor 1 (SDF-1) were obtained from 354 human immunodeficiency virus type 1 (HIV-1)-positive subjects who were being treated with nucleosides. Associations with HIV-1 load, HIV syncytium-inducing (SI) phenotype, CD4 cell count, and disease progression were analyzed. No differences in HIV-1 load or CD4 cell count were observed between wild type (+) and variant genotypes. Changes from non-SI to SI viral phenotype were more frequent in heterozygotes with a 32-bp deletion (Delta32) in the CCR5 gene than in + homozygotes (40% vs. 7%; P=.01). In a multivariate analysis, heterozygous CCR5 Delta32 was associated with reduced hazard of progression (hazard ratio, 0.32; P=.02). Subjects homozygous for the SDF-1 3'A variant had more-rapid disease progression (P=.008). The SDF-1 homozygous 3'A variant was related to more-rapid disease progression, and CCR5 Delta32 was associated with reduced rates of hazard for disease progression in nucleoside-treated subjects.

Nelfinavir, efavirenz, or both after the failure of nucleoside treatment of HIV infection

BACKGROUND

The optimal antiretroviral treatment for patients who have human immunodeficiency virus (HIV) viremia despite treatment with nucleoside reverse-transcriptase inhibitors (nucleoside analogues) remains uncertain. We studied treatment with regimens that combined two nucleoside analogues, at least one of which was new, with the protease inhibitor nelfinavir, the nonnucleoside reverse-transcriptase inhibitor efavirenz, or both.

METHODS

The study included 195 patients who had been treated with nucleoside analogues only, and had a plasma HIV type 1 (HIV-1) RNA level of at least 500 copies per milliliter. Patients were randomly assigned to receive, in addition to two nucleoside analogues, nelfinavir, efavirenz, or nelfinavir plus efavirenz. The primary end point was a plasma HIV-1 RNA level of less than 500 copies per milliliter at week 16. A secondary end point was the composite of the HIV-1 RNA levels measured at weeks 40 and 48.

RESULTS

At week 16 and at weeks 40 and 48, the proportions of patients in whom a plasma HIV-1 RNA level of less than 500 copies per milliliter was achieved were, respectively, 81 percent and 74 percent in the nelfinavir-plus-efavirenz group, 69 percent and 60 percent in the efavirenz group, and 64 percent and 35 percent in the nelfinavir group. Quadruple therapy resulted in a higher rate of viral suppression in both the short term (P=0.03) and the long term (P=0.001) than did triple therapy with nelfinavir. Triple therapy with efavirenz conferred a higher rate of long-term suppression than triple therapy with nelfinavir (P=0.004). Quadruple therapy also achieved a higher rate of virologic suppression than triple therapy with efavirenz (P=0.008).

CONCLUSIONS

In HIV-infected patients previously treated with nucleoside analogues, treatment with nelfinavir plus efavirenz and at least one new nucleoside analogue achieves a higher rate of viral suppression than do regimens with nucleoside analogues and nelfinavir or efavirenz alone.

Genotypic correlates of a virologic response to stavudine after zidovudine monotherapy

Prior evidence suggests that resistance to zidovudine (ZDV) confers some degree of cross-resistance to stavudine (d4T), but no genotypic correlates of clinical d4T susceptibility and resistance exist. To identify the genotypic correlates of a virologic response to d4T, reverse transcriptase (RT) sequencing of archived plasma HIV isolates was performed on 31 subjects who received d4T monotherapy in the AIDS Clinical Trials Group 302 study, all of whom received more than 3 years of ZDV monotherapy. Baseline characteristics and all RT mutations were analyzed for impact on virologic suppression. Eight of 31 subjects (27%) achieved a virologic response of greater than 0.3 log reduction in plasma HIV RNA after 8 weeks of d4T. Responders were more likely to have lower median baseline viral loads (4.2 vs. 4.7; p =.01) and a trend toward fewer ZDV-associated mutations (median: 1 vs. 2; p =.09). No subject with greater than one ZDV mutation had a virologic response to d4T. Seven of the 8 responders had only a K70R mutation at baseline. We conclude that in patients with prior ZDV treatment, those with only one ZDV mutation, particularly at position 70, can still get reasonable virologic activity from d4T. Those with more mutations are not likely to have much benefit.

Virologic and CD4 cell response to zidovudine or zidovudine and lamivudine following didanosine treatment of human immunodeficiency virus infection

To optimize nucleoside reverse transcriptase inhibitor (nRTI) antiretroviral therapy, 137 subjects who had been treated with didanosine monotherapy for more than 3 years in the AIDS Clinical Trials Group (ACTG) 175 study were randomized to zidovudine and didanosine (dual therapy) or zidovudine, didanosine, and lamivudine (triple therapy). Evaluation of early (8 week) change in HIV plasma RNA demonstrated that addition of lamivudine and zidovudine provided significantly greater virologic suppression compared to the addition of zidovudine alone (mean decrease of 1.27 vs. 0.74 log(10) copies/ml, n = 108, p = 0.007). Both dual and triple therapy provided significant long-term decreases (from study entry to mean at Weeks 40 and 48) in HIV plasma RNA: 0.62 and 0.86 log(10) copies/ml, respectively (n = 110). However, the difference between treatments was not significant (p = 0.16). At 48 weeks, 26% of subjects starting study treatment had <500 copies/ml of plasma HIV RNA. The CD4 count response was greater at 4 weeks for triple versus dual therapy: a mean increase of 51 vs. 12 CD4 cells/ml(3) (n = 126, p = 0.039). The difference at Weeks 40 and 48 was not significant (a 22 cell increase vs. a 1 cell decrease, n = 129, p = 0.41). Zidovudine and didanosine treatment, with or without lamivudine, was well tolerated and only 2 of 137 (1.5%) of study participants developed an AIDS-defining event over 48 weeks.

Effect of lamivudine in HIV-infected persons with prior exposure to zidovudine/didanosine or zidovudine/zalcitabine

Nucleoside analog-based regimens remain an integral component of combination therapy for use in both antiretroviral treatment-naive and experienced HIV-infected patients. To further define treatment responses to new antiretroviral therapy in patients with long-term experience to dual nucleoside analog therapy (zidovudine [ZDV] plus didanosine [ddI] or ZDV plus zalcitabine [ddC]), 325 subjects derived from the AIDS Clinical Trials Group (ACTG) 175 trial were randomized to three different combination regimens: (1) continuation of ZDV + ddI or ZDV + ddC (continuation arm), (2) addition of 3TC to ZDV + ddI or ZDV + ddC (addition arm), or (3) a switch to ZDV + 3TC therapy (switch arm). Both the addition and switch arms sustained significantly greater short-term (baseline to week 4) mean CD4+ cell count increases compared with the continuation arm (+36, +28 versus -4 cells/mm3; p = 0.012) and long-term CD4+ cell count responses (baseline to weeks 40/48: +32, +19 versus -9 cells/mm3; p = 0.003). Superior short-term (baseline to week 8) mean decreases in plasma HIV RNA (p < 0.001) were achieved by both the addition and switch arms (0.53 log10 and 0.54 log10 copies/ml, respectively) compared with the continuation arm (0.13 copies/ml) whereas no differences in long-term virologic suppression were observed (p = 0.30). At week 48, no differences were observed in the proportions of subjects who had HIV RNA levels below 500 copies/mL: 18% of subjects in each treatment arm (3-way p = 1.0). Overall, the treatments were well tolerated and only nine subjects (3%) died or developed one or more AIDS-defining events. While this study confirms the intrinsic antiretroviral activity of 3TC, only modest marker changes and limited short-term viral suppression are seen with incremental addition of the drug. The current approach of using 3TC in maximally suppressive regimens is preferred.

Differences between women and men in adverse events and CD4+ responses to nucleoside analogue therapy for HIV infection. The Aids Clinical Trials Group 175 Team

OBJECTIVE

To prospectively examine differences in baseline characteristics and study outcomes between HIV-infected women and men during a clinical trial of nucleoside analogue therapy.

METHODS

ACTG 175 randomized HIV-infected patients with CD4+ counts between 200 and 500 cells/mm3 to one of four nucleoside analogue regimens: zidovudine (ZDV), didanosine (ddI), ZDV + ddI, or ZDV + zalcitabine (ddC). Differences in time to first dose modification, voluntary withdrawal, development of toxicity and symptomatology, and AIDS progression were compared by gender.

RESULTS

The study included 438 women and 2029 men. Baseline values of HIV RNA plasma concentrations were significantly lower for women (0.3 log10) than men in a subset of patients in whom assays were taken and this difference persisted after adjustment for CD4+ count. Women reported reducing dosage and discontinue ddI-containing regimens more frequently than men did; adjustment for weight did not completely explain this difference. Women were at lower risk than men for progression to a study endpoint (19% of women versus 24% of men; p <.0001). Among those antiretroviral-naive study subjects receiving ZDV, men were four times more likely to progress to a study endpoint than women.

CONCLUSIONS

Differences in pretreatment characteristics and on study experiences were demonstrated between women and men enrolled in this clinical trial. The suggestion of a gender difference in response to ZDV monotherapy by antiretroviral-naive study subjects and the lower baseline values for HIV RNA in women compared with those in men provides evidence for gender differences in the relationship between virus replication, CD4+ decline, and responses to nucleoside analogue therapy.

Virologic and CD4+ cell responses to new nucleoside regimens: switching to stavudine or adding lamivudine after prolonged zidovudine treatment of human immunodeficiency virus infection. ACTG 302 Study Team. AIDS Clinical Trials Group

Clinical benefit of zidovudine alone in the treatment of HIV infection wanes after several years, with decreasing CD4+ cell numbers and increasing HIV RNA in plasma. To develop treatment strategies following prolonged zidovudine treatment, 92 subjects from the AIDS Clinical Trials Group (ACTG) 175 study after a median of 3.6 years of zidovudine monotherapy were randomized to treatment with stavudine or zidovudine and lamivudine. Evaluation of long-term changes, the average of 40- and 48-week HIV plasma RNA, demonstrated that lamivudine and zidovudine provided significantly greater virologic suppression compared with stavudine (mean decrease 0.70 versus 0.18 1og10 copies/ml,p = 0.003). Twenty-nine percent of zidovudine plus lamivudine recipients had HIV RNA levels below 500 copies per milliliter at 48 weeks as compared with 4% of stavudine recipients (p = 0.02). Both regimens significantly increased CD4+ cell numbers, the means of weeks 40 and 48 rose to 49 and 36 CD4+ cells per cubic millimeter among zidovudine plus lamivudine and stavudine recipients, respectively. Treatments were well tolerated and only 3 of 92 subjects died or developed AIDS within 48 weeks. In zidovudine-experienced subjects, addition of lamivudine resulted in significantly decreased plasma HIV RNA levels at 48 weeks compared with treatment with stavudine alone.

HIV type 1 envelope subtype C sequences from recent seroconverters in Zimbabwe

HIV-1 envelope sequence patterns have implications for virus cell tropism and for the development of an effective vaccine. To identify the sequence characteristics of recently transmitted HIV-1 isolates in southern Africa, we sequenced the V3-V5 envelope regions of 24 male seroconverters in Harare, Zimbabwe. Each of the sequences clustered with previously reported subtype C isolates and there was a mean 17% intersequence pairwise genetic distance between the Zimbabwean isolates. Three isolates were syncytium inducing (SI). One of the SI isolates had an unusual GIGK crown and a deletion at codon 23; one had the codon 23 deletion alone; and one had a high net positive charge in the V3 loop. The extensive genetic diversity within the envelope of subtype C HIV-1 isolates must be considered in vaccine development. Further analysis of subtype C SI isolates and site-directed mutagenesis experiments are required to determine the molecular basis of SI activity in global HIV-1 isolates.

Report of sexually transmitted diseases by HIV infected men during follow up: time to target the HIV infected?

OBJECTIVES

To compare the rate of self reported sexually transmitted diseases (STDs) among HIV infected men with men who remained HIV negative during follow up of a Harare male factory cohort.

METHODS

Male factory workers were offered enrolment and behavioural data were collected at entry then every 6 months, along with HIV testing. Self report of STDs was used to calculate incidence per 100 person years. Cox proportional hazards models examined independent risk factors for STDs, with hazard ratios (HRs).

RESULTS

At entry 20% of men were HIV infected and 11% reported STDs in the previous year. A total of 2777 (82%) of 3383 men enrolled were followed at least once. Compared with men who remained HIV negative, seroconverters had the highest incidence of STDs (16.8 per 100 person years; IRR = 3.3, 95% CI = 2.5-4.3); men enrolled HIV positive also reported higher STD incidence (14.5 per 100 person years, IRR = 2.8; 95% CI 2.3-5.5). Among HIV positive men, the only independent risk factor for report of urethral discharge was history of multiple partners (HR = 10, 95% CI 1.4-73.2).

CONCLUSION

HIV positive men reported threefold higher incidence of STDs than HIV negative men, many related to high risk sexual behaviour.

Adherence as a particular issue with protease inhibitors

Suboptimal therapeutic doses of HIV protease inhibitors lead to the emergence of drug resistance and reduced drug efficacy. It is imperative, then, that patients and clinicians alike are fully educated about the importance of patients taking all the pills in these new, admittedly complex, antiretroviral regimens. With protease inhibitors especially, missing doses and/or taking drug holidays or partial doses will mean the rapid emergence of HIV isolates that are resistant to these drugs.

Both serum HIV type 1 RNA levels and CD4+ lymphocyte counts predict clinical outcome in HIV type 1-infected subjects with 200 to 500 CD4+ cells per cubic millimeter. AIDS Clinical Trials Group Study 175 Virology Study Team

To evaluate HIV-1 RNA and CD4+ cell responses to therapy as predictors of clinical progression and to evaluate levels and trends of these markers prior to clinical failure, HIV-1 RNA measurements were retrospectively obtained on subjects who progressed to AIDS or death and a random sample of subjects who did not. Samples were taken from AIDS Clinical Trials Group Study 175, a randomized trial comparing nucleoside analog therapies in subjects with CD4+ cell counts of between 200 and 500 cells/mm3. HIV-1 RNA and CD4+ cell count independently predicted clinical progression. Risk of subsequent progression is best captured by the change to the last measured value for CD4+ cell count and the area under the curve minus baseline, a measure of viral replication over time, for HIV-1 RNA. Subjects who failed had lower CD4+ cell counts, greater rates of CD4+ cell decline, and higher HIV-1 RNA levels, but not greater rates of HIV-1 RNA increase than subjects who did not. Subjects who maintained more than 200 CD4+ cells/mm3 and fewer than 10,000 copies of HIV-1 RNA per milliliter had low risk of progression. During the first few months of therapy, treatments are best monitored by regular HIV-1 RNA and less frequent CD4+ cell measurements. Thereafter, both markers should be monitored on a similar schedule to identify rapidly declining CD4+ cell counts, or adverse levels of either. These results further delineate the prognostic significance of HIV-1 RNA and CD4+ cell count and should help to better define their utility in the practice setting.

Efavirenz- and adefovir dipivoxil-based salvage therapy in highly treatment-experienced patients: clinical and genotypic predictors of virologic response

OBJECTIVE

To determine the impact of prior nonnucleoside reverse transcriptase inhibitor (NNRTI) therapy, genotypic resistance, and other variables on response to efavirenz (EFV)- and adefovir dipivoxil (ADV)-based salvage therapy.

DESIGN

Retrospective clinical cohort study.

SETTING

One university and one community-based HIV clinic.

STUDY SUBJECTS

All 33 patients who were coenrolled in both the EFV and ADV expanded access programs.

INTERVENTIONS

Patients received EFV 600 mg/day and ADV 120 mg/day in addition to other antiretroviral agents.

OUTCOME MEASURE

HIV viral load (<500 copies/ml) at 12 and 24 weeks.

RESULTS

10 of 33 (30%) patients at 12 weeks and 8 of 33 (24%) patients at 24 weeks had viral loads <500 copies/ml. Prior NNRTI use and a history of any NNRTI-associated mutations predicted failure. Patients with Y181C or G190A single mutations had an initial greater magnitude of viral load suppression than those with K103N, but this advantage was short lived. No one with any NNRTI mutations responded with a viral load <500 copies/ml at 12 or 24 weeks.

CONCLUSIONS

EFV/ADV-based salvage yielded viral load suppression at 24 weeks in 42% (8 of 19) of patients who were highly NRTI and protease inhibitor experienced but NNRTI naive. NNRTI-experienced study subjects had a poor response regardless of the specific NNRTI resistance mutation they harbored.

Antiretroviral therapy in adults: updated recommendations of the International AIDS Society-USA Panel

OBJECTIVE

To update recommendations for antiretroviral therapy for adult human immunodeficiency virus type 1 (HIV-1) infection, based on new information and drugs that are available.

PARTICIPANTS

A 17-member international physician panel with antiretroviral research and HIV patient care experience initially convened by the International AIDS Society-USA in December 1995.

EVIDENCE

Available clinical and basic science data including phase 3 controlled trials; data on clinical, virologic, and immunologic end points; research conference reports; HIV pathogenesis data; and panel expert opinion. Recommendations were limited to therapies available (US Food and Drug Administration approved) in 1999.

CONSENSUS PROCESS

The panel assesses new research reports and interim results and regularly meets to consider how the new data affect therapy recommendations. Recommendations are updated via full-panel consensus. Guidelines are presented as recommendations if the supporting evidence warrants routine use in the particular situation and as considerations if data are preliminary or incomplete but suggestive.

CONCLUSIONS

The availability of new antiretroviral drugs has expanded treatment choices. The importance of adherence, emerging long-term complications of therapy, recognition and management of antiretroviral failure, and new monitoring tools are addressed. Optimal care requires individualized management and ongoing attention to relevant scientific and clinical information in the field.

Delayed-type hypersensitivity to recombinant HIV envelope glycoprotein (rgp160) after immunization with homologous antigen

Delayed-type hypersensitivity (DTH) responses to intradermal recombinant HIV envelope glycoprotein (rgp160) may assess cell-mediated immune responses to HIV envelope. In three studies, DTH and lymphocyte proliferation responses to rgp160 were obtained in a total of 106 HIV-seropositive subjects with CD4+ counts >400 cells/mm3. Several subjects participated in more than one study. Before immunization, DTH responses were seen in 5 of 56 (9%) of HIV-infected study subjects. After immunization with an alum-adjuvanted experimental rgp160 vaccine, DTH responses were seen in 46 of 52 (89%). Using in vitro lymphocyte proliferation activity (LPA) to rgp160 as an indication of cellular immune response, skin testing has a sensitivity of 0.75 (95% confidence Interval [CI], 0.59-0.88) and a specificity of 0.84 (95% CI, 0.72-0.92). Biopsy samples of skin that had tested positive confirmed the presence of a DTH reaction with a predominance of CD4+ T cells in the perivascular, inflammatory infiltrate. Skin testing before and after immunization with candidate AIDS vaccines could provide a simple method in the field to assess new cell mediated immune responses.

Syphilis serology and HIV infection in Harare, Zimbabwe

OBJECTIVE

To determine the reliability of serological tests in detecting syphilis in a factory worker cohort and examine the impact of concurrent HIV infection on serological tests for syphilis.

METHOD

Reactions to non-treponemal and treponemal antigens were tested using sera from a cohort of 3401 factory workers in Harare, Zimbabwe. The participants consented to regular testing for syphilis, by VDRL, and HIV using two ELISAs. All sera from men who were VDRL positive, and a random sample of VDRL negative sera, were tested by RPR, TPHA, and where appropriate FTA-Abs. From the results, men were defined as having no syphilis, active syphilis, incident syphilis, historic syphilis, or giving biological false positive reactions.

RESULTS

709 sera were examined from 580 men. There were 78 cases of active syphilis in the cohort, giving a prevalence of 2.3%, and the seroincidence was 0.25 per 100 person years of follow up. The prevalence of HIV in the cohort was 19.8%. There was a strong association between syphilis, whether active, incident or historic, and HIV seropositivity. With both HIV positive and negative sera the negative predictive values of VDRL and RPR were > 99.9% while the positive predictive value for VDRL (30%) was lower than for RPR (39%). Biological false positive reactions were detected in 0.5% of the cohort, with in most cases a transient rise in VDRL titres up to < 1/16. Higher false positive titres occurred in five men, each of whom was HIV positive.

CONCLUSIONS

The VDRL is reliable in detecting possible cases of syphilis even in a community with a high prevalence of heterosexually transmitted HIV. There is need, however, for confirmatory tests. The prevalence of syphilis in this cohort is very low in comparison with other countries in southern Africa, but is consistent with recent data from Harare. Despite a strong association between syphilis and HIV it was clear that syphilis could not be counted as a major factor fueling the HIV epidemic in Zimbabwe.

The contribution of assay variation and biological variation to the total variability of plasma HIV-1 RNA measurements. The Women Infant Transmission Study Clinics. Virology Quality Assurance Program

OBJECTIVES

To assess the specific contributions of assay variation and biological variation to the total variation of plasma HIV-1 RNA measured by the Roche Monitor assay and the extent to which batch assays reduced both assay variability and total variability compared with real-time determinations.

DESIGN

A retrospective analysis of data obtained from three trials conducted by the Adult and Pediatric AIDS Clinical Trials Groups (ATCG), the Women and Infants Transmission Study (WITS) and the NIAID-sponsored Virology Quality Assurance Program.

METHODS

Within-subject variation was assessed from stored, serially collected plasma samples from 663 subjects enrolled in the ACTG and WITS studies. Interassay and intra-assay variation were estimated from two of the clinical trials and 22 laboratories that participated in a quality assurance program and were used to estimate the effect of real-time testing on total variation.

RESULTS

The total variation (standard deviation) from a random effects model was 0.26 log10 RNA copies/ml. The estimated interassay variation was 0.08 log10 and intra-assay variation was 0.12 log10 RNA copies/ml. Biological variation accounted for 56-80% of total variation. The effect of real-time testing compared with batch testing was minimal.

CONCLUSION

Our estimates of total within-subject HIV-1 RNA variation support the current recommendation to obtain at least two specimens, preferably obtained less than 2 weeks apart, for viral RNA measurement before starting therapy. The major contribution of biological variation to the total variation supports the use of real-time HIV-1 RNA assays, provided that consistent specimen collection procedures are followed and acceptable assay proficiency is maintained.

Serum level of maternal human immunodeficiency virus (HIV) RNA, infant mortality, and vertical transmission of HIV in Zimbabwe

Maternal human immunodeficiency virus (HIV) RNA load, vertical transmission of subtype C HIV, and infant mortality were examined in 251 HIV-seropositive women and their infants in Zimbabwe. Demographic characteristics, health and medical histories, serum HIV RNA loads, and CD4+ lymphocyte counts for mothers were examined by logistic regression analysis to determine significant risk factors and their odds ratios for transmission and infant mortality. Tenfold (1 log10) incremental increases in maternal HIV RNA were associated with a 1.9-fold increase (95% confidence interval [CI], 1.2-2.9) in transmission and a 2.1-fold increase (95% CI, 1.3-3.5) in infant mortality (P<.01). Maternal CD4 cell counts and demographic and medical characteristics were not significant predictors of transmission. However, maternal CD4 cell counts below the median (400/mm3) were significantly associated with infant mortality (P=. 035, Fisher's exact test). The maternal level of serum HIV is an important determinant of vertical transmission and infant mortality in subtype C infection in Zimbabwe.

Primary subtype C HIV-1 infection in Harare, Zimbabwe

Heterosexual transmission of HIV-1 is widespread in Southern Africa. Heteroduplex mobility assays (HMA) and phylogenetic analyses of V3-V5 envelope (env) gene sequences demonstrate that subtype C predominates in Zimbabwe. To elucidate factors contributing to the epidemic in Zimbabwe, clinical and virologic characteristics of recently acquired subtype C HIV-1 infection among 21 men and 1 woman were determined. In 12 of 19 men providing clinical histories, a sexually transmitted infection preceded serologic evidence of HIV-1, and 14 of 19 men complained of rash or fever before seroconversion. Quantitative p24 antigen levels, reverse transcriptase activity, and HIV RNA levels of 22 viral isolates correlated with in vitro infectivity in peripheral blood mononuclear cells (p < .05). Biologic phenotype assessed in MT-2 cells demonstrated that 3 of 22 isolates (14%) were syncytia inducing (SI) and the remaining 19 nonsyncytium inducing (NSI). Early growth of virus in culture was associated with increased plasma HIV RNA levels, decreased CD4 cell levels, and SI virus. Recent subtype C HIV-1 infection through heterosexual transmission in Zimbabwe demonstrated clinical and virologic features consistent with reports of seroconversion to subtype B viruses.

Detection of Kaposi's sarcoma-associated herpesvirus in peripheral blood cells in human immunodeficiency virus infection: association with Kaposi's sarcoma, CD4 cell count, and HIV RNA levels

Kaposi's sarcoma-associated herpesvirus (KSHV) DNA, consistently found in Kaposi's sarcoma (KS) tissues, was sought in peripheral blood mononuclear cells (PBMCs) of HIV-infected individuals. To determine quantitative relationships between the presence of KSHV DNA in PBMCs, CD4 cell counts, plasma HIV RNA levels, and the development of KS, we designed a cross-sectional study of prospectively collected PBMC samples from ongoing cohort studies. PBMCs were collected from 142 HIV-seropositive individuals in California, 7 of whom had a clinical diagnosis of KS. KSHV sequences were detected in extracted PBMC DNA by nested polymerase chain amplification using two nonoverlapping primer sets. KSHV DNA was detected in PBMCs of 5 of 7 (71%) subjects with KS and in 18 of 135 (13%) HIV-infected subjects without KS. Among HIV-seropositive individuals without KS, detection of KSHV was more common in men than women (19 versus 4%, p = 0.01) and was associated with lower mean CD4 percent (14.8 versus 20.7% CD4 cells, p = 0.03), lower mean CD4 cell count (244 versus 334 CD4 cells/microl, p = 0.05), and higher geometric mean plasma HIV RNA (4.83 versus 4.03 1og10 copies/ml, p = 0.0002). Semiquantitative analysis found 5 to 15,625 copies of KSHV per microgram of PBMC DNA with increased plasma HIV RNA levels and a trend toward increased subsequent development of KS in subjects with higher KSHV loads. The association of the presence of KSHV DNA in PBMCs with lower CD4 cell counts and higher plasma HIV RNA provides evidence of a relationship between immunosuppression, HIV replication, and KSHV expression.