Virological failure after 1 year of first-line ART is not associated with HIV minority drug resistance in rural Cameroon .

OBJECTIVES: The aim of this study was to describe clinical and virological outcomes in therapy-naive HIV-1-positive patients treated in a routine ART programme in rural Cameroon. METHODS: In a prospective cohort, 300 consecutive patients starting first-line ART were enrolled and followed for 12 months. Among 238 patients with available viral load data at Month 12, logistic regression was used to analyse risk factors for virological failure (≥1000 HIV RNA copies/mL) including clinical, immunological and virological parameters, as well as data on drug adherence. Population sequencing was performed to detect the presence of drug-resistance mutations in patients with virological failure at Month 12; minority drug-resistance mutations at baseline were analysed using next-generation sequencing in these patients and matched controls. RESULTS: At Month 12, 38/238 (16%) patients experienced virological failure (≥1000 HIV RNA copies/mL). Patients with virological failure were younger, had lower CD4 cell counts and were more often WHO stage 3 or 4 at baseline. Sixty-three percent of patients with virological failure developed at least one drug-resistance mutation. The M184V (n = 18) and K103N (n = 10) mutations were most common. At baseline, 6/30 patients (20%) experiencing virological failure and 6/35 (17%) matched controls had evidence of minority drug-resistance mutations using next-generation sequencing (P = 0.77). Lower CD4 count at baseline (OR per 100 cells/mm(3) lower 1.41, 95% CI 1.02-1.96, P = 0.04) and poorer adherence (OR per 1% lower 1.05, 95% CI 1.02-1.08, P < 0.001) were associated with a higher risk of virological failure. Unavailability of ART at the treatment centre was the single most common cause for incomplete adherence. CONCLUSIONS: Virological failure after 1 year of ART was not associated with minority drug resistance at baseline but with incomplete adherence. Strategies to assure adherence and uninterrupted drug supplies are pivotal factors for therapy success.

Hodgkin lymphoma is as common as non-Hodgkin lymphoma in HIV-positive patients with sustained viral suppression and limited immune deficiency: a prospective cohort study.

OBJECTIVES: The incidence of HIV-related non-Hodgkin lymphoma (NHL) but not that of Hodgkin lymphoma (HL) has been declining. The aim of the study was to compare HIV-infected patients with NHL and HL with respect to antiretroviral therapy (ART) exposure at the time of lymphoma diagnosis. METHODS: HIV-infected patients with NHL and HL included in a prospective multicentre cohort study since January 2005 were compared with respect to ART exposure and viral load at the time of lymphoma diagnosis. RESULTS: As of 31 December 2012, data for 329 patients with NHL and 86 patients with HL from 31 participating centres were available. Patients with HL were more likely to be on ART (73.5% vs. 39.1%, respectively; P < 0.001) and more frequently had a viral load below the detection limit (57.3% vs. 27.9%, respectively; P < 0.001) than patients with NHL. The proportion of patients with HL was 8.0% in ART-naïve patients, 34.8% in patients with current HIV RNA < 50 HIV-1 RNA copies/mL, and 50.0% in patients with both HIV RNA < 50 copies/mL for > 12 months and a CD4 cell count of > 200 cells/µL. Of note, 45.8% of all patients with NHL were not currently on ART and had a CD4 count of < 350 cells/µL. CONCLUSIONS: This prospective cohort study shows that HL was as common as NHL in patients with sustained viral suppression and limited immune deficiency. In contrast to NHL, the majority of patients with HL were on effective ART, suggesting that ART provides insufficient protection from developing HL. The high proportion of untreated patients with NHL suggests missed opportunities for earlier initiation of ART.

[Cost of Illness of HIV Patients under Anteretroviral Therapy in Germany - Results of the 48-Week Interim Analysis of the Prospective Multicentre Observational Study 'CORSAR']. / Krankheitskosten von HIV-Patienten unter antiretroviraler Therapie in Deutschland - Ergebnisse einer 48-Wochen-Interimsanalyse im Rahmen der prospektiven multizentrischen Kohortenstudie "CORSAR".

BACKGROUND: With the introduction of highly active combined antiretroviral therapy (c-ART) mortality and morbidity of HIV patients declined substantially. Earlier studies reported that c-ART was able to save health-care costs due to a reduction of other direct medical costs, particularly for inpatient treatments and concomitant medication. To date, analyses of costs and health-related quality of life (HRQOL) of patients under c-ART are lacking in Germany. Hence, this study aims to estimate the current cost of illness and HRQOL of HIV-patients under c-ART in different treatment lines. METHODS: A multicenter, prospective observational study was carried out in 12 specialised German centres for infectious diseases: 8 private practices/outpatient centres and 4 specialised hospitals offering both inpatient and outpatient services. Demographic, clinical and medication data were derived from patient records. Resource utilisation, information on productivity, out of pocket costs and HRQOL (EQ-5D) were collected every 12 weeks via a patient questionnaire. All costs were calculated based on price information from publicly accessible databases. RESULTS: N=1,154 patients were included in the analysis. Mean direct disease-related costs of -patients under c-ART amounted to 22,563 Euro/year. Patients beyond the 3(rd) line of treatment -incurred considerably higher costs 24,654 Euro/year. In the 1(st) treatment line, c-ART accounted for 83.2% of the total direct costs, in the 2(nd)/3(rd) line for 80.8% and in >3(rd) line for 83.4%, respectively. Indirect costs due to impaired productivity were higher in the 2(nd)/3(rd) treatment line (2,843 Euro) compared to the 1(st) (1,604 Euro) and >3(rd) (1,752 Euro) treatment lines, respectively. The average HRQOL (EQ-5D) varied between 0.77 (self-assessment via visual analogue scale) and 0.91 (utility score based on the German time trade-off tariff). CONCLUSIONS: Over the last decade, cost of illness of HIV patients under c-ART decreased slightly with average costs per year still being substantial. Main cost driver of overall costs is c-ART. There have been, however, noticeable shifts between different cost domains.

Immune activation despite suppressive highly active antiretroviral therapy is associated with higher risk of viral blips in HIV-1-infected individuals.

OBJECTIVES: Viral blips are thought to represent random biological variations around a steady state of residual HIV viraemia and to lack clinical significance. We aimed to assess the association of immune activation and the occurrence of blips. METHODS: HIV-infected patients from our out-patient cohort who developed a blip after having been on fully suppressive highly active antiretroviral therapy (HAART) for at least 180 days were matched with patients without blips according to duration of complete viral suppression (CVS), age, sex and Centers for Disease Control and Prevention (CDC) stage. Frequencies of CD3(+), CD3(+) CD4(+), CD3(+) CD8(+), CD3(+) HLA-DR(+), CD4(+) CD45RA(+), CD16(+) CD56(+) CD3(-) and CD19(+) cells, as well as C-reactive protein (CRP) levels and clinical parameters, were included in conditional logistic regression models. Adherence to HAART was assessed by measuring prescribed nonnucleoside reverse transcriptase inhibitor (NNRTI) or protease inhibitor (PI) plasma levels in a sample of 57 patients. RESULTS: Eighty-two patients with viral blip were matched with 82 controls from the same cohort. The mean age was 47.2 years [standard deviation (SD) 12.1 years], 80.5% of patients were male and 42.7% had CDC stage C disease. Viral blips occurred after a median of 14 months [interquartile range (IQR) 8-34 months] of CVS. In the logistic regression, activated CD3(+) HLA-DR(+) lymphocytes [odds ratio (OR) 1.25 per 100 cells/µL; 95% confidence interval (CI) 1.02-1.54; P = 0.03] were significantly associated with blips and there was a trend for an association of longer time on HAART with blips (OR 1.31 per year; 95% CI 0.96-1.78; P = 0.09). No between-group difference regarding subtherapeutic drug levels was found (P = 0.46). CONCLUSIONS: The occurrence of viral blips after suppressive HAART was associated with elevated markers of T-cell activation. Blips may identify a subset of patients with higher immune activation and increased risk for HIV disease progression.

Late presentation for HIV diagnosis and care in Germany.

OBJECTIVES: Antiretroviral therapy reduces mortality and morbidity in HIV-infected individuals most markedly when initiated early, before advanced immunodeficiency has developed. Late presentation for diagnosis and care remains a significant challenge. To guide public health interventions effectively it is crucial to describe the factors associated with late presentation. METHODS: Case surveillance data for all individuals newly diagnosed with HIV infection in Germany in the years 2001-2010 and data for the years 1999-2010 from the German Clinical Surveillance of HIV Disease (ClinSurv) cohort study, a large multicentre observational study, were analysed. Factors associated with late presentation (CD4 count < 350 cells/µL or clinical AIDS) were assessed using descriptive statistics and multivariable logistic regression methods. RESULTS: Among 22 925 eligible patients in the national surveillance database, 49.5% were late presenters for HIV diagnosis. Among 6897 treatment-naïve patients in the ClinSurv cohort, 58.1% were late presenters for care. Late presenters for care were older (median 42 vs. 39 years for early presenters), more often heterosexuals from low-prevalence countries (18.1% vs. 15.5%, respectively) and more often migrants (18.2% vs. 9.7%, respectively; all P < 0.005). The probability of late presentation was >65% throughout the observation period in migrants. The probability of late presentation for care clearly decreased in men who have sex with men (MSM) from 60% in 1999 to 45% in 2010. CONCLUSIONS: In Germany, the numbers of late presenters for HIV diagnosis and care remain high. The probability of late presentation for HIV diagnosis seems to be particularly high for migrants. These results argue in favour of targeted test promotion rather than opt-out screening. Late presentation for care seems to be an additional problem after HIV diagnosis.

Clinical outcome of HIV-infected patients with discordant virological and immunological response to antiretroviral therapy.

BACKGROUND: A subgroup of human immunodeficiency virus type 1 (HIV-1)-infected patients with severe immunodeficiency show persistently low CD4+ cell counts despite sustained viral suppression. It is unclear whether this immuno-virological discordance translates into an increased risk for clinical events. METHODS: Data analysis from a large multicenter cohort incorporating 14,433 HIV-1-infected patients in Germany. Treatment-naive patients beginning antiretroviral therapy (ART) with CD4+ cell counts <200 cells/µL who achieved complete and sustained viral suppression <50 copies/mL (n = 1318) were stratified according to the duration of immuno-virological discordance (failure to achieve a CD4+ cell count ≥200 cells/µL). Groups were compared by descriptive and Poisson statistics. The time-varying discordance status was analyzed in a multivariable Cox model. RESULTS: During a total of 5038 person years of follow-up, 42 new AIDS events occurred. The incidence rate of new AIDS events was highest in the initial 6 months of complete viral suppression (immuno-virological discordance group, 55.06; 95% confidence interval [CI], 30.82-90.82; and immune responder group, 24.54; 95% CI, 10.59-48.35) and decreased significantly by 65% per year in patients with immuno-virological discordance (incidence risk ratio, 0.35; 95% CI, 0.14-0.92; P = .03). Immuno-virological discordance and prior AIDS diagnosis were independently associated with new AIDS events (hazard ratio, 3.10; 95% CI, 1.09-8.82; P = .03). CONCLUSION: Compared with immune responders, patients with immuno-virological discordance seem to remain at increased risk for AIDS. Absolute risk is greatly reduced after the first 6 months of complete viral suppression.

The unenlarged lymph nodes of HIV-1-infected, asymptomatic patients with high CD4 T cell counts are sites for virus replication and CD4 T cell proliferation. The impact of highly active antiretroviral therapy.

The efficacy of triple drug therapy for HIV-1 infection encourages its early use to prevent damage to the immune system. We monitored the effects of such therapy on 12 patients with 14-75-mo histories of minimal disease, i.e., CD4+ counts constantly >500/microl and little or no lymph node enlargement. In this way, we could first determine the extent of viral replication and immunoarchitectural changes in unenlarged nodes early in disease, and second follow the response to triple therapy in plasma and lymphoid tissue in tandem. As is known for lymph nodes with more advanced disease, the germinal centers showed productively infected T cells, i.e., CD4+CD1a-CD68- cells labeling intensely for HIV-1 RNA after in situ hybridization. The unenlarged nodes also showed extensive HIV-1 RNA retention on a well-preserved, follicular dendritic cell (FDC) network, and the follicles were abnormal. There were numerous CD8+ cells, many expressing TIA-1 granule antigen. Also, in contrast to normal follicles, CD4+ T cell proliferation was active, with marked increases in the number of cycling, Ki-67+CD4+CD45R0+ cells. After 28 d and 3 mo of therapy, productively infected T cells decreased dramatically and often were not apparent. The labeling of the FDC network for viral RNA also decreased, but not for gag protein. We conclude that HIV-1 replicates and accumulates in lymphoid organs before damage of the immune system, that at this stage of disease de novo production of T cells occurs in the lymphoid tissue, and that the infection is sensitive to triple drug therapy in both plasma and lymph nodes.

Measuring recent thymic emigrants in blood of normal and HIV-1-infected individuals before and after effective therapy.

The role of the thymus in HIV-1 pathogenesis remains unclear. We developed an assay to quantify the number of recent thymic emigrants in blood based on the detection of a major excisional DNA byproduct (termed alpha1 circle) of T cell receptor rearrangement. By studying 532 normal individuals, we found that alpha1 circle numbers in blood remain high for the first 10-15 yr of life, a sharp drop is seen in the late teen years, and a gradual decline occurs thereafter. Compared with age-matched uninfected control individuals, alpha1 circle numbers in HIV-1-infected adults were significantly reduced; however, there were many individuals with normal alpha1 circle numbers. In 74 individuals receiving highly active antiretroviral therapy, we found no appreciable effect on alpha1 circle numbers in those whose baseline values were already within the normal range, but significant increases were observed in those with a preexisting impairment. The increases in alpha1 circle numbers were, however, numerically insufficient to account for the rise in levels of naive T lymphocytes. Overall, it is difficult to invoke thymic regenerative failure as a generalized mechanism for CD4 lymphocyte depletion in HIV-1 infection, as alpha1 circle numbers are normal in a substantial subset of HIV-1-infected individuals.

History of viral suppression on combination antiretroviral therapy as a predictor of virological failure after a treatment change.

OBJECTIVES: HIV-infected persons experience different patterns of viral suppression after initiating combination antiretroviral therapy (cART). The relationship between such differences and risk of virological failure after starting a new antiretroviral could help with patient monitoring strategies. METHODS: A total of 1827 patients on cART starting at least one new antiretroviral from 1 January 2000 while maintaining a suppressed viral load were included in the analysis. Poisson regression analysis identified factors predictive of virological failure after baseline in addition to traditional demographic variables. Baseline was defined as the date of starting new antiretrovirals. RESULTS: Four hundred and fifty-one patients (24.7%) experienced virological failure, with an incidence rate (IR) of 7.3 per 100 person-years of follow-up (PYFU) [95% confidence interval (CI) 6.7-8.0]. After adjustment, patients who had rebounded in the year prior to baseline had a 2.4-times higher rate of virological failure after baseline (95% CI 1.77-3.26; P<.0001), while there was no increased incidence in patients whose last viral rebound was >3 years prior to baseline [Incidence rate ratio (IRR) 1.06; 95% CI 0.75-1.50; P=0.73] compared with patients who had never virally rebounded. Patients had an 86% (95% CI 1.36-2.55; P<.0001), 53% (95% CI 1.06-2.04; P=0.02) and 5% (95% CI 0.80-1.38; P=0.72) higher virological failure rate after baseline if they were virally suppressed <50%, 50-70% and 70-90% of the time they were on cART prior to baseline, respectively, compared with those virally suppressed >90% of the time. DISCUSSION: Intensive monitoring after a treatment switch is required in patients who have rebounded recently or have a low percentage of time suppressed while on cART. Consideration should be given to increasing the provision of adherence counselling.

HIV-induced immune activation: pathogenesis and clinical relevance - summary of a workshop organized by the German AIDS Society (DAIG e.v.) and the ICH Hamburg, Hamburg, Germany, November 22, 2008.

This manuscript is communicated by the German AIDS Society (DAIG) (www.daignet.de). It summarizes a series of presentations and discussions during a workshop on immune activation due to HIV infection. The workshop was held on November 22nd 2008 in Hamburg, Germany. It was organized by the ICH Hamburg under the auspices of the German AIDS Society (DAIG e.V.).

Aymptomatic CMV viremia is associated with increased levels of serum amyloid A in patients with advanced HIV-infection.

OBJECTIVE: We evaluated assays for the measurement of acute phase protein levels in plasma for their usefulness to identify sensitively an inflammatory response to active cytomegalovirus CMV infection in HIV-infected patients. METHODS: Plasma samples were collected from 28 CMV-seropositive patients with advanced HIV-infection (CD4-cell count <200/microl) before commencement of antiretroviral therapy. Sensitivity, specificity, and area under receiver operating characteristic curve for the selected acute phase protein assays (haptoglobin, fibronectin, high-sensitivity C-reactive protein (hs-CRP), human interleukin-6, serum amyloid A (SAA), and human lipopolysacharide binding protein) were compared with results of a CMV-specific PCR assay. RESULTS: CMV viremia was detectable in 8/28 patients. Levels of SAA correlated well with those of hs-CRP (r' = 0.439, P = 0.019 (Spearman rank correlation)). Levels of SAA >3 mg/L discriminated with 100% sensitivity and 40% specificity between HIV-infected patients with and without active CMV infection. Sensitivity of fibronectin was 100% and specificity 15% at a threshold-value corresponding with the lower limit of normal values as defined by the manufacturer of the assay (>29 mg/dL). Levels of the other acute phase proteins evaluated did not correlate with detection of CMV-DNA in plasma. CONCLUSION: Increased levels of SAA indicate sensitively an inflammatory response to active CMV infection. Use of a CMV-specific virological assay is required to confirm the specificity of a high SAA-level but may be limited to samples with high SAA-levels. Hence, screening for increased levels of SAA in patients with advanced HIV-infection may allow early identification of active CMV infection.

Intestinal Kaposi's sarcoma may mimic gastrointestinal stromal tumor in HIV infection.

Diffuse intestinal Kaposi's sarcoma shares macroscopic and histopathologic features with gastrointestinal stromal tumors. Correct diagnosis may pose a clinical challenge. We describe the case of a young HIV-1-infected African lady without advanced immunodeficiency, who presented with a diffuse spindle cell tumor of the gut. Initial diagnosis was of a gastrointestinal stromal tumor, based on endoscopy and histopathology. Further evaluation revealed evidence for human herpesvirus 8 (HHV8) and the diagnosis had to be changed to diffuse intestinal Kaposi's sarcoma. Antiretroviral triple therapy together with chemotherapy was commenced, and has led to the rapid remission of intestinal lesions. With a background of HIV infection, the presence of HHV8 as the causative agent of Kaposi's sarcoma should be determined, as distinct treatment is indicated.

Consensus recommendation from a group of German experts for the use of enfuvirtide in heavily pretreated HIV patients.

BACKGROUND: The EU approval of enfuvirtide (Fuzeon) was granted in May 2003 on the basis of the 48-week data from the TORO 1 and TORO 2 studies. Enfuvirtide is licensed for use in pretreated HIV patients experienced with three classes of drugs who exhibited treatment failure or who have shown intolerance to previous antiretroviral treatment regimens. Recent studies with the new protease inhibitors tipranavir and darunavir (RESIST and POWER studies) showed that a high proportion of heavily pretreated HIV patients achieve a viral load reduction to below the limit of detection when treated with enfuvirtide plus one of these new ritonavir-boosted protease inhibitors and an optimised background treatment regimen. The International AIDS Society (IAS-USA Panel) has recently updated its treatment guidelines in view of these new data and recommends the use of an antiretroviral treatment regimen containing at least two active drugs, one of which that has a new mechanism of action, for HIV patients who have been heavily pretreated. A new treatment goal has also emerged for heavily pretreated patients with advanced HIV disease: reduction of the viral load to below the detection limit of 50 copies/ml. The IAS concluded that the likelihood of achieving this treatment goal is higher when enfuvirtide is selected as one of the two active drugs. OBJECTIVE: A panel of German experts convened to discuss the currently available data and to incorporate them into the updated German consensus recommendations for the use of enfuvirtide when switching treatment in heavily pretreated HIV patients. METHODS: The consensus recommendations are based on published data from controlled, randomised clinical studies and on the expert opinions of the discussants. RESULTS AND CONCLUSIONS: The consensus recommendations were developed to provide practice-relevant standardised recommendations for selecting suitable candidates for enfuvirtide therapy and for their management. Aspects including predictive prognostic factors, disease stage, selection of the optimised background regimen, early indicators of a response to enfuvirtide, as well as accompanying educational measures treatment were considered. New protease inhibitors or other remaining active drugs should be used together with enfuvirtide in heavily pretreated patients in order to enable at least two active drugs to be included in such a salvage regimen.

Predictors of virological success and ensuing failure in HIV-positive patients starting highly active antiretroviral therapy in Europe: results from the EuroSIDA study.

BACKGROUND: Predictors of virological response to highly active antiretroviral therapy (HAART) have never been systematically evaluated in a large continental multicenter cohort of unselected human immunodeficiency virus (HIV)-infected people. OBJECTIVE: To determine the factors related to achieving and maintaining undetectable plasma HIV-1 RNA levels among HIV-1-infected patients first starting protease inhibitor- or nonnucleoside retrotranscriptase inhibitor-containing HAART in Europe. DESIGN: Prospective multicenter cohort study. SETTING: Fifty-two clinical centers in 17 European countries included in the EuroSIDA Study Group, from August 1996 to April 1999. PATIENTS: A total of 1469 HIV-positive patients first starting HAART recruited from an unselected cohort of more than 7300 HIV-positive patients. MAIN OUTCOME MEASURE: Detection of factors related to virological success after first starting HAART (baseline) and ensuing failure by standard survival techniques, including Kaplan-Meier techniques and Cox proportional hazards models. All analyses were intention to treat. RESULTS: Most patients (80%) achieved plasma HIV-1 RNA levels of less than 500 copies/mL during follow-up (60.4% at 6 months from the onset of HAART). Patients with higher baseline HIV-1 RNA levels (relative hazard [RH], 0.76 per log higher; 95% confidence interval [CI], 0.69-0.84; P<.001) and those taking saquinavir mesylate hard gel as a single protease inhibitor (RH, 0.62; 95% CI, 0.47-0.82; P<.001) were less likely to reach undetectable HIV-1 RNA levels. Conversely, higher CD4+ lymphocyte counts (RH per 50% higher, 1.09; 95% CI, 1.02-1.16; P = .008) and the initiation of 3 or more new antiretroviral drugs (RH, 1.29; 95% CI, 1.03-1.61; P = .02) were independent predictors of higher success. Once success was achieved, HIV-1 RNA levels rebounded in more than one third of all patients during follow-up (24% at 6 months). Antiretroviral-naive patients (RH, 0.50; 95% CI, 0.29-0.87; P = .01), older patients (RH, 0.86 per year older; 95% CI, 0.75-0.99; P = .04), and those starting a protease inhibitor other than saquinavir hard gel (RH, 0.66; 95% CI, 0.44-0.98; P = .04) were at decreased hazard for virological failure. Higher baseline HIV-1 RNA level (RH, 1.18 per log higher; 95% CI, 0.99-1.40; P = .06) and a longer time to achieve virological success (RH per 12 months, 1.53; 95% CI, 0.99-2.38; P = .06) were marginally significant predictors of a decreased hazard of ensuing virological failure. CONCLUSIONS: HAART is associated with a favorable virological response if started when the baseline HIV-1 RNA level is low, if at least 2 new nucleoside retrotranscriptase inhibitors are added, and if standard doses of saquinavir hard gel capsule are avoided as a single protease inhibitor. Older patients are more likely to achieve virological success. Thereafter, the higher durability of virological response is predicted by an antiretroviral-naive status and by the use of specific regimens. Lower baseline HIV-1 RNA levels and rapid maximal viral suppression seem to be other important factors in the durability of virological response.

The use of and response to second-line protease inhibitor regimens: results from the EuroSIDA study.

OBJECTIVE: To describe the use of second line protease-inhibitor (PI) regimens across Europe and to determine factors associated with virological and immunological response. DESIGN: Analysis of data from 984 patients with a median follow-up of 21 months enrolled in EuroSIDA. Patients started their second PI-containing regimen at least 16 weeks after starting the first PI-containing regimen and with viral load > 1000 copies/ml. METHODS: Virological response was defined as a viral load < 500 copies/ml and immunological response as an increase of 50 x 10(6)/l or more in CD4 lymphocyte count. RESULTS: The median CD4 cell count at starting the second PI was 171 x 10(6) cells/l; viral load was 4.45 log copies/ml. As a second PI regimen, 45% were using a dual PI, while of those on one PI, indinavir (42%) and nelfinavir (34%) were most common. In multivariate Cox models, a higher viral load at starting the second PI [relative hazard (RH), 0.67 per 1 log higher; 95% confidence interval (CI), 0.58-0.77; P < 0.0001) and a lower CD4 cell count (RH, 1.15 per 50% higher; 95% CI, 1.06-1.26; P = 0.0014) were associated with a reduced probability of virological response. Those who had achieved viral suppression on the first PI-regimen were more likely to respond to the second (RH, 1.65; 95% CI, 1.30-2.10; P < 0.0001) as were those who added one or two new nucleosides to their second PI. CONCLUSIONS: Patients who initiate a second PI regimen at lower viral load, higher CD4 cell count or who added new nucleosides tended to be more likely to achieve a viral load < 500 copies/ml. The roles of cross-resistance and adherence in response to second-line regimens needs further investigation.

Rapid plasma virus and CD4+ T-cell turnover in HIV-1 infection: evidence for an only transient interruption by treatment.

OBJECTIVES: To analyse the short-term kinetics of viral plasma RNA and CD4+ T cells numbers in patients with different initial CD4+ T-cell counts treated with different antiretroviral regimens. METHODS: In 10 HIV-1 positive patients, in vivo kinetics of plasma HIV RNA and CD4+ T cells were studied during antiretroviral treatment. Lymphocyte subpopulation analysis, quantitative polymerase chain reaction (PCR), p24 antigen enzyme immunoassay (EIA) and beta 2-microglobulin EIA were performed at days 0, 3, 7, 10, 14, 21 and 28 of treatment. One additional patient served as a control. The resulting curves were fitted. Half-lives were calculated using the time constant T of decrease or increase [T1/2 = In(2) x T]. Calculations of virus and CD4+ T-cell turnover were multiplied by the total blood volume. RESULTS: Viral plasma RNA half-life ranged from 1.1 to 5.1 days, independent of prior or actual treatment and initial CD4+ T-cell count. The calculated peripheral blood viral plasma RNA turnover varied between 0.02 and 55.8 x 10(8) copies/ml/day and showed some negative correlation with initial CD4+ T-cell counts. CD4+ T-cell turnover estimates ranged from 0.01 to 7.5 x 10(8) cells/day. Most patients showed an immediate reincrease of virus load after the nadir. Changes in HIV p24 antigen paralleled HIV plasma RNA in p24 antigen-positive patients. beta 2-microglobulin decreased until day 7-15 in all but one case and rapidly reincreased to pretreatment values. CONCLUSIONS: The kinetics of virus and CD4+ T-cell turnover are uniformly rapid throughout a wide range of initial CD4+ T-cell counts. The magnitude of virus turnover varies considerably among individuals and appears to be inversely related to the initial CD4+ T-cell count. These data also argue for a rapid resumption of virus production and lymphocyte turnover during treatment.

Asymptomatic HIV infection is characterized by rapid turnover of HIV RNA in plasma and lymph nodes but not of latently infected lymph-node CD4+ T cells.

OBJECTIVES: To study the kinetics of plasma viraemia and HIV-infected lymph-node cells in stable asymptomatic HIV infection with high CD4+ T-cell counts. METHODS: Nine asymptomatic HIV-infected patients with stable CD4+ T-cell counts (510-1350 x 10(6)/l) were treated with a triple-drug combination. Plasma viraemia was determined at days 0, 3, 7, 10, 14, 21 and 28 of treatment [Roche polymerase chain reaction (PCR) and ultrasensitive PCR assay]. Sequential lymph-node biopsies were examined in four patients before and after 4 weeks of treatment. Productively infected cells were counted in lymph-node sections (in situ hybridization). The infection rates of FACS-sorted CD4+ lymph-node T cells and the expression of single-spliced, double-spliced and full-length HIV transcripts were determined. RESULTS: HIV plasma RNA half-lives ranged from 1.4 to 2.7 days. Viral turnover varied between 0.07 and 7.54 x 10(8) copies per day. The number of productively infected lymph-node cells as well as the amount of extracellular virus in germinal centres was markedly reduced during treatment, paralleled by a clearance of single-spliced, double-spliced and full-length HIV transcripts from CD4+ lymph-node T cells. Plasma viraemia remained detectable with an ultrasensitive PCR assay in three out of four patients. The percentage of lymph-node CD4+ T cells harbouring proviral DNA decreased only slightly. CONCLUSIONS: The kinetics of HIV replication are rapid in stable asymptomatic infection, and the magnitude of replication varies considerably. Productively infected lymph-node cells and extracellular virus in germinal centres undergo a rapid turnover, whereas latently infected CD4+ T cells have a lower rate of turnover. The latter may contribute substantially to viral persistence during therapy.

Germinal centre CD4+ T cells are an important site of HIV replication in vivo.

OBJECTIVE: CD4+ T cells are the main target for HIV. However, the highest HIV antigen concentration in infected subjects accumulates on the cell surface of follicular dendritic cells in the germinal centres of the lymphoid tissue. Germinal centres contain a T-helper cell subset which expresses CD57 molecules. Here we analysed virus replication and viral load in CD57+CD4+ germinal centre T cells and in the CD4+ T cells found mostly outside germinal centres (CD57-CD4+). METHODS: Peripheral blood mononuclear cells and lymph-node cells were prepared, stained for CD4 and CD57 and purified by FACS. Defined cell numbers of CD4+CD57+ cells and CD4+CD57- cells were sorted directly into polymerase chain reaction (PCR) tubes by FACS, equipped with an automated cell deposition unit and analysed by PCR to detect proviral DNA. Based on Poisson distribution, the expected level of infection was calculated. Viral replication was determined by amplifying double-spliced, single-spliced, and full-length transcripts of HIV using serially diluted cDNA of the FACS-sorted cells. RESULTS: An up to 10-fold higher frequency of infected cells was found in the CD57+CD4+ germinal centre T cells compared with CD57-CD4+ T cells. Furthermore, active viral replication was detected almost exclusively in the CD57+CD4+ T cells. CONCLUSIONS: The CD57+CD4+ germinal centre T cells are one of the sites of HIV infection and replication that may play a pivotal role in the pathogenesis of HIV infection.

Protease inhibitor-containing regimens compared with nucleoside analogues alone in the suppression of persistent HIV-1 replication in lymphoid tissue.

OBJECTIVE: Lymphoid tissue provides a reservoir where HIV can persist. However, therapies incorporating a protease inhibitor can target this reservoir. This study was designed to investigate the relative long-term effects on lymph-node viral load and cellular architecture of regimens containing multiple nucleosides alone or in combination with protease inhibitors. METHODS: Axillary lymph-node biopsies from 12 patients with undetectable viraemia (viral load < 20 copies/ml: mean CD4 cells 525 x 10(6)/l) for a mean period of 25 months (range, 10-52 months) were investigated for the presence of HIV by in situ hybridization and coculture. Four patients were receiving multiple nucleoside analogues alone or in one case with a suboptimally dosed protease inhibitor (group I). Protease inhibitor was added to the regimen of seven patients at least 6 months prior to lymph-node biopsy (group II). Standard flow cytometry and virological data were obtained from peripheral blood every 3 months. RESULTS: By in situ hybridization, more productively infected CD4+ T cells were found in the lymph nodes of group I patients treated with nucleoside analogues alone. Very low numbers of productively infected lymph node cells were detected in the protease inhibitor-treated group II. No trapping of virions on the follicular dendritic cell (FDC) network was detectable in protease inhibitor-treated patients. In contrast, large deposits of FDC-bound virions were observed in three out of five patients from group I. Virus cultures from lymph node cells were positive in these three group I patients compared with only one out of seven patients from group II. Sequencing reverse transcriptase and protease genes from these isolates revealed typical mutations conferring resistance to the previously administered nucleoside analogue. A more preserved lymph node architecture and less signs of immunopathological change were also observed in protease inhibitor-treated patients. CONCLUSIONS: Undetectable plasma viraemia using the ultrasensitive PCR assay for prolonged periods of time does not always reflect complete HIV-1 suppression within the lymphoid compartment. Our results suggest that protease inhibitor-containing regimens target HIV reservoirs in lymphoid tissue more effectively and preserve or restore lymph node architecture.

Intensification of background antiretroviral therapy with abacavir during low-level failure may restore optimal suppression.

OBJECTIVE: To investigate the antiviral activity of abacavir added to stable background therapy. DESIGN: Retrospective analysis. MATERIALS AND METHODS: In 27 subjects with detectable plasma viraemia during stable treatment abacavir was added as the only agent. Patients were pre-treated for 180 weeks (mean) with regimens containing zidovudine (102 weeks) and lamivudine (88 weeks). Results were analysed in two groups: group 1, > 400 HIV RNA copies/ml; group 2, 25-399 copies/ml. In 7/13 group 1 patients genotypic resistance analysis was performed prior to abacavir. RESULTS: Median follow-up was 28 weeks, median HIV RNA load at baseline 2.48 log10 copies/ml (3.52 and 1.66 log10 copies/ml in groups 1 and 2, respectively). Plasma viraemia was reduced to less than 400 HIV RNA copies/ml in 2/13 subjects in group 1 and 11/11 in group 2 (week 24). Only one patient in group 1 responded transiently to less than 25 HIV RNA copies/ml. In contrast, 10/14 and 11/11 in group 2 reached values below this threshold at weeks 12 and 24, respectively. Overall, 7/13 group 1 patients were found with > or = 2 zidovudine resistance-associated mutations. The lamivudine resistance-associated mutation M184V was present in four of seven cases. All of these patients showed only a moderate and transient reduction of plasma viraemia (medium peak reduction of 0.73 log10 after 20 weeks). CONCLUSIONS: The addition of abacavir during low-level treatment failure may restore or achieve suppression to levels below the cut-off of the ultrasensitive PCR.