CSF/plasma HIV-1 RNA discordance even at low levels is associated with up-regulation of host inflammatory mediators in CSF.

INTRODUCTION: HIV-1 RNA can be found at higher levels in cerebrospinal fluid (CSF) than in plasma, termed CSF/plasma discordance. The clinical significance of CSF/plasma discordance is not known and the degree of discordance considered important varies. We aimed to determine whether a panel of CSF cytokines, chemokines and associated mediators were raised in patients with CSF/plasma discordance at different levels. METHODS: A nested case-control study of 40 CSF samples from the PARTITION study. We used a cytometric bead array to measure CSF mediator concentrations in 19 discordant and 21 non-discordant samples matched for plasma HIV-1 RNA. Discordant samples were subdivided into 'high discordance' (>1log10) and 'low discordance' (0.5-1log10, or ultrasensitive discordance). CSF mediators significant in univariate analysis went forward to two-way unsupervised hierarchical clustering based on the patterns of relative mediator concentrations. RESULTS: In univariate analysis 19 of 21 CSF mediators were significantly higher in discordant than non-discordant samples. There were no significant differences between samples with high versus low discordance. The samples grouped into two clusters which corresponded to CSF/plasma discordance (p<0.0001). In cluster one all mediators had relatively high abundance; this included 18 discordant samples and three non-discordant samples. In cluster two all mediators had relatively low abundance; this included 18 non-discordant samples and one non-discordant sample with ultrasensitive discordance only. CONCLUSIONS: CSF/plasma discordance is associated with potentially damaging neuroinflammatory process. Patients with discordance at lower levels (ie. 0.5-1log10) should also be investigated as mediator profiles were similar to those with discordance >1log10. Sensitive testing may have a role to determine whether ultrasensitive discordance is present in those with low level CSF escape.

Discordant CSF/plasma HIV-1 RNA in patients with unexplained low-level viraemia.

The central nervous system has been proposed as a sanctuary site where HIV can escape antiretroviral control and develop drug resistance. HIV-1 RNA can be at higher levels in CSF than plasma, termed CSF/plasma discordance. We aimed to examine whether discordance in CSF is associated with low level viraemia (LLV) in blood. In this MRC-funded multicentre study, we prospectively recruited patients with LLV, defined as one or more episode of unexplained plasma HIV-1 RNA within 12 months, and undertook CSF examination. Separately, we prospectively collected CSF from patients undergoing lumbar puncture for a clinical indication. Patients with durable suppression of viraemia and no evidence of CNS infection were identified as controls from this group. Factors associated with CSF/plasma HIV-1 discordance overall were examined. One hundred fifty-three patients were recruited across 13 sites; 40 with LLV and 113 undergoing clinical lumbar puncture. Seven of the 40 (18 %) patients with LLV had CSF/plasma discordance, which was significantly more than 0/43 (0 %) with durable suppression in blood from the clinical group (p = 0.005). Resistance associated mutations were shown in six CSF samples from discordant patients with LLV (one had insufficient sample for testing), which affected antiretroviral therapy at sampling in five. Overall discordance was present in 20/153 (13 %) and was associated with nadir CD4 but not antiretroviral concentrations in plasma or CSF. CSF/plasma discordance is observed in patients with LLV and is associated with antiretroviral resistance associated mutations in CSF. The implications for clinical practice require further investigation.

Ineffective central nervous system HIV suppression of once-a-day maraviroc and ritonavir-boosted darunavir dual therapy: four case reports.

Novel two-drug combinations including a protease inhibitor are an attractive nucleoside reverse transcriptase inhibitor sparing option for some patients, particularly as a switch strategy. We have used the two-drug combination of maraviroc and darunavir/ritonavir once a day as a switch strategy in patients with stable low or undetectable plasma HIV viral loads, but identified four patients who failed on this combination, indicating it may be insufficient to prevent replication of neurotropic HIV in treatment-experienced patients. Further investigation of our cases highlighted the need for a better understanding of the plasma and cerebro-spinal fluid (CSF) pharmacodynamics of these drugs.

Neurocognitive function in HIV-infected patients: comparison of two methods to define impairment.

OBJECTIVE: To compare two definitions of neurocognitive impairment (NCI) in a large clinical trial of effectively-treated HIV-infected adults at baseline. METHODS: Hopkins Verbal Learning test-Revised (HVLT-R), Colour Trail (CTT) and Grooved Pegboard (GPT) tests were applied exploring five cognitive domains. Raw scores were transformed into Z-scores and NCI defined as summary NPZ-5 score one standard deviation below the mean of the normative dataset (i.e. <-1SD) or Z-scores <-1SD in at least two individual domains (categorical scale). Principal component analysis (PCA) was performed to explore the contribution of individual tests to the total variance. RESULTS: Mean NPZ-5 score was -0.72 (SD 0.98) and 178/548 (32%) participants had NPZ-5 scores <-1SD. When impairment was defined as <-1SD in at least two individual tests, 283 (52%) patients were impaired. Strong correlations between the two components of the HVLT-R test (learning/recall) (r = 0.73), and the CTT and (attention/executive functioning) (r = 0.66) were observed. PCA showed a clustering with three components accounting for 88% of the total variance. When patients who scored <-1SD only in two correlated tests were considered as not impaired, prevalence of NCI was 43%. When correlated test scores were averaged, 36% of participants had NPZ-3 scores <-1SD and 32% underperformed in at least two individual tests. CONCLUSION: Controlling for differential contribution of individual test-scores on the overall performance and the level of correlation between components of the test battery used appear to be important when testing cognitive function. These two factors are likely to affect both summary scores and categorical scales in defining cognitive impairment. TRIAL REGISTRATION: EUDRACT: 2007-006448-23 and ISRCTN04857074.

Impact on life expectancy of HIV-1 positive individuals of CD4+ cell count and viral load response to antiretroviral therapy.

OBJECTIVE: The objective of this study is to estimate life expectancies of HIV-positive patients conditional on response to antiretroviral therapy (ART). METHODS: Patients aged more than 20 years who started ART during 2000-2010 (excluding IDU) in HIV clinics contributing to the UK CHIC Study were followed for mortality until 2012. We determined the latest CD4 cell count and viral load before ART and in each of years 1-5 of ART. For each duration of ART, life tables based on estimated mortality rates by sex, age, latest CD4 cell count and viral suppression (HIV-1 RNA <400 copies/ml), were used to estimate expected age at death for ages 20-85 years. RESULTS: Of 21 388 patients who started ART, 961 (4.5%) died during 110 697 person-years. At start of ART, expected age at death [95% confidence interval (CI)] of 35-year-old men with CD4 cell count less than 200, 200-349, at least 350 cells/µl was 71 (68-73), 78 (74-82) and 77 (72-81) years, respectively, compared with 78 years for men in the general UK population. Thirty-five-year-old men who increased their CD4 cell count in the first year of ART from less than 200 to 200-349 or at least 350 cells/µl and achieved viral suppression gained 7 and 10 years, respectively. After 5 years on ART, expected age at death of 35-year-old men varied from 54 (48-61) (CD4 cell count <200 cells/µl and no viral suppression) to 80 (76-83) years (CD4 cell count ≥350 cells/µl and viral suppression). CONCLUSION: Successfully treated HIV-positive individuals have a normal life expectancy. Patients who started ART with a low CD4 cell count significantly improve their life expectancy if they have a good CD4 cell count response and undetectable viral load.

Failure to achieve a CD4+ cell count response on combination antiretroviral therapy despite consistent viral load suppression.

OBJECTIVE: To assess CD4 cell count recovery in people severely immunosuppressed at start of antiretroviral therapy (ART) who achieve and maintain viral load suppression. METHODS: Eligible participants from the UK Collaborative HIV Cohort Study started ART with at least three drugs after 1 January 2000. Participants were required to have pre-ART CD4 cell count below 100 cells/µl, at least 2 years of follow-up on ART, have achieved viral load suppression (≤ 50 copies/ml) by 9 months after starting ART and to have maintained this throughout follow-up. Participants were further required to be regularly engaged with care. We calculated the proportion of people who failed to achieve a CD4 cell count of more than 100, 150, 200, 350 and 500 cells/µl by the time of the last follow-up, or 5 years from start of ART, whichever occurred first (censoring date). RESULTS: Of the 400 participants [median (interquartile range) pre-ART CD4 cell count of 38 (14-65) cells/µl], 2 (0.5%), 8 (2%), 28 (7%), 131 (33%) and 259 (65%) failed to achieve a CD4 cell count of more than 100, 150, 200, 350 and 500 cells/µl, by the censoring date, respectively. Kaplan-Meier estimates of the proportion of people reaching each CD4 cell count threshold after 1 year on ART were 88, 70, 50, 14 and 3%, respectively, and after 3 years on ART, 98, 95, 90, 59 and 25%, respectively. Median (interquartile range) follow-up on ART was 3.9 (2.7-4.8) years. CONCLUSION: Given a person with pre-ART CD4 cell count below 100 cells/µl survives and maintains consistent viral load suppression on ART, there is over a 90% chance of reaching a CD4 cell count above 200 cells/µl by 3 years.

Effects of hydroxychloroquine on immune activation and disease progression among HIV-infected patients not receiving antiretroviral therapy: a randomized controlled trial.

CONTEXT: Therapies to decrease immune activation might be of benefit in slowing HIV disease progression. OBJECTIVE: To determine whether hydroxychloroquine decreases immune activation and slows CD4 cell decline. DESIGN, SETTING, AND PATIENTS: Randomized, double-blind, placebo-controlled trial performed at 10 HIV outpatient clinics in the United Kingdom between June 2008 and February 2011. The 83 patients enrolled had asymptomatic HIV infection, were not taking antiretroviral therapy, and had CD4 cell counts greater than 400 cells/µL. INTERVENTION: Hydroxychloroquine, 400 mg, or matching placebo once daily for 48 weeks. MAIN OUTCOME MEASURES: The primary outcome measure was change in the proportion of activated CD8 cells (measured by the expression of CD38 and HLA-DR surface markers), with CD4 cell count and HIV viral load as secondary outcomes. Analysis was by intention to treat using mixed linear models. RESULTS: There was no significant difference in CD8 cell activation between the 2 groups (-4.8% and -4.2% in the hydroxychloroquine and placebo groups, respectively, at week 48; difference, -0.6%; 95% CI, -4.8% to 3.6%; P = .80). Decline in CD4 cell count was greater in the hydroxychloroquine than placebo group (-85 cells/µL vs -23 cells/µL at week 48; difference, -62 cells/µL; 95% CI, -115 to -8; P = .03). Viral load increased in the hydroxychloroquine group compared with placebo (0.61 log10 copies/mL vs 0.23 log10 copies/mL at week 48; difference, 0.38 log10 copies/mL; 95% CI, 0.13 to 0.63; P = .003). Antiretroviral therapy was started in 9 patients in the hydroxychloroquine group and 1 in the placebo group. Trial medication was well tolerated, but more patients reported influenza-like illness in the hydroxychloroquine group compared with the placebo group (29% vs 10%; P = .03). CONCLUSION: Among HIV-infected patients not taking antiretroviral therapy, the use of hydroxychloroquine compared with placebo did not reduce CD8 cell activation but did result in a greater decline in CD4 cell count and increased viral replication. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN30019040.

The posterior reversible encephalopathy syndrome in HIV infection.

Posterior reversible encephalopathy syndrome (PRES) is often associated with hypertension, however recent advances in the understanding of this condition have shown that endothelial dysfunction is responsible for much of the pathogenesis and the condition can occur in the absence of hypertension. This case describes a 32-year-old lady with untreated HIV infection who developed PRES at a normal blood pressure and without opportunistic infection or other conditions known to precipitate PRES. HIV, particularly when untreated, is associated with endothelial dysfunction and this may have been sufficient to cause PRES in this patient. To our knowledge this is the first case to describe PRES in HIV without uncontrolled hypertension, sepsis or other precipitating cause.

Does discordancy between the CD4 count and CD4 percentage in HIV-positive individuals influence outcomes on highly active antiretroviral therapy?

INTRODUCTION: The CD4 count and CD4 percentage (CD4%) are both strong predictors of clinical disease progression in human immunodeficiency virus (HIV). Although individuals may show discordancy between their CD4 count and CD4%, the clinical relevance of this is unclear. METHODS: Discordancy was defined where the CD4% was ≤10th percentile for a selected CD4 count range (referred to as low discordancy), within the central 80% range (concordant), or ≥90th percentile (high discordancy). Regression methods identified factors associated with low and high discordancy in untreated individuals and assessed the impact of discordancy on treatment responses to highly active antiretroviral therapy (HAART). RESULTS: High discordancy was associated with female sex, low viral load, and white ethnicity; low discordancy was associated with black or nonwhite ethnicity, older age, and injection drug use. Clinical event rates were higher in individuals with high discordancy starting HAART, but there was no association with subsequent HIV progression by 6 months after starting HAART. CD4 count increases remained lower, by 20 cells/mm(3), in individuals with low discordancy, and higher, by 27 cells/mm(3), in those with high discordancy. CONCLUSIONS: Overall discrepancies between the CD4/CD4% are small, confirming the use of absolute CD4 counts as a monitoring tool.

Once daily maraviroc 300 mg or 150 mg in combination with ritonavir-boosted darunavir 800/100 mg.

OBJECTIVES: To describe the pharmacokinetics of maraviroc when dosed at 150 or 300 mg once daily with 800/100 mg of darunavir/ritonavir. METHODS: A retrospective case-note review of HIV-infected adults taking maraviroc was conducted. Patients on a maraviroc-based regimen for a minimum of 5 weeks were grouped as receiving: (i) 300 mg of maraviroc twice daily with 245 mg of tenofovir/200 mg of emtricitabine; (ii) 300 mg of maraviroc once daily with 800/100 mg of darunavir/ritonavir once daily; and (iii) 150 mg of maraviroc once daily with 800/100 mg of darunavir/ritonavir once daily. C(trough) and C(peak) data were collected at 2, 12 or 24 h post-dose. RESULTS: Sixty-six patients were included, providing 115 samples. The median (IQR) C(peak) was 378 (350-640) ng/mL for 300 mg of maraviroc twice daily with 245 mg of tenofovir/200 mg of emtricitabine (n=9), 728 (378-935) ng/mL for 300 mg of maraviroc once daily with darunavir/ritonavir (n=29) and 364 (104-624) ng/mL for 150 mg of maraviroc once daily with darunavir/ritonavir (n=2; P=0.24). The median (IQR) C(trough) was 46 (33-61) ng/mL for 300 mg of maraviroc twice daily with 245 mg of tenofovir/200 mg of emtricitabine (n=12), 70 (49-97) ng/mL for 300 mg of maraviroc once daily with darunavir/ritonavir (n=34) and 43 (35-55) ng/mL for 150 mg of maraviroc once daily with darunavir/ritonavir (n=17; P=0.001). The maraviroc C(trough) in black patients (n=34) was 61 (45-110) ng/mL and in white patients (n=29) it was 49 (42-70) ng/mL (P=0.04). The C(peak) in black patients (n=20) was 800 (397-1060) ng/mL versus 387 (336-723) ng/mL in white patients (n=20; P=0.02). CONCLUSIONS: Once daily coadministration of 300 mg of maraviroc with 800/100 mg of darunavir/ritonavir was well tolerated and had favourable pharmacokinetics when compared with 300 mg of maraviroc twice daily with 245 mg of tenofovir/200 mg of emtricitabine. A 24% higher C(trough) and 107% higher C(peak) was seen in black patients compared with white patients.

Impact of late diagnosis and treatment on life expectancy in people with HIV-1: UK Collaborative HIV Cohort (UK CHIC) Study.

OBJECTIVES: To estimate life expectancy for people with HIV undergoing treatment compared with life expectancy in the general population and to assess the impact on life expectancy of late treatment, defined as CD4 count <200 cells/mm(3) at start of antiretroviral therapy. DESIGN: Cohort study. SETTING: Outpatient HIV clinics throughout the United Kingdom. Population Adult patients from the UK Collaborative HIV Cohort (UK CHIC) Study with CD4 count ≤ 350 cells/mm(3) at start of antiretroviral therapy in 1996-2008. MAIN OUTCOME MEASURES: Life expectancy at the exact age of 20 (the average additional years that will be lived by a person after age 20), according to the cross sectional age specific mortality rates during the study period. RESULTS: 1248 of 17,661 eligible patients died during 91,203 person years' follow-up. Life expectancy (standard error) at exact age 20 increased from 30.0 (1.2) to 45.8 (1.7) years from 1996-9 to 2006-8. Life expectancy was 39.5 (0.45) for male patients and 50.2 (0.45) years for female patients compared with 57.8 and 61.6 years for men and women in the general population (1996-2006). Starting antiretroviral therapy later than guidelines suggest resulted in up to 15 years' loss of life: at age 20, life expectancy was 37.9 (1.3), 41.0 (2.2), and 53.4 (1.2) years in those starting antiretroviral therapy with CD4 count <100, 100-199, and 200-350 cells/mm(3), respectively. CONCLUSIONS: Life expectancy in people treated for HIV infection has increased by over 15 years during 1996-2008, but is still about 13 years less than that of the UK population. The higher life expectancy in women is magnified in those with HIV. Earlier diagnosis and subsequent timely treatment with antiretroviral therapy might increase life expectancy.

Early and prolonged antiretroviral therapy is associated with an HIV-1-specific T-cell profile comparable to that of long-term non-progressors.

BACKGROUND: Intervention with antiretroviral treatment (ART) and control of viral replication at the time of HIV-1 seroconversion may curtail cumulative immunological damage. We have therefore hypothesized that ART maintenance over a very prolonged period in HIV-1 seroconverters could induce an immuno-virological status similar to that of HIV-1 long-term non-progressors (LTNPs). METHODOLOGY/PRINCIPAL FINDINGS: We have investigated a cohort of 20 HIV-1 seroconverters on long-term ART (LTTS) and compared it to one of 15 LTNPs. Residual viral replication and reservoirs in peripheral blood, as measured by cell-associated HIV-1 RNA and DNA, respectively, were demonstrated to be similarly low in both cohorts. These two virologically matched cohorts were then comprehensively analysed by polychromatic flow cytometry for HIV-1-specific CD4(+) and CD8(+) T-cell functional profile in terms of cytokine production and cytotoxic capacity using IFN-γ, IL-2, TNF-α production and perforin expression, respectively. Comparable levels of highly polyfunctional HIV-1-specific CD4(+) and CD8(+) T-cells were found in LTTS and LTNPs, with low perforin expression on HIV-1-specific CD8(+) T-cells, consistent with a polyfunctional/non-cytotoxic profile in a context of low viral burden. CONCLUSIONS: Our results indicate that prolonged ART initiated at the time of HIV-1 seroconversion is associated with immuno-virological features which resemble those of LTNPs, strengthening the recent emphasis on the positive impact of early treatment initiation and paving the way for further interventions to promote virological control after treatment interruption.

HIV-associated central nervous system diseases in the recent combination antiretroviral therapy era.

BACKGROUND AND PURPOSE: Data describing the incidence and survival of HIV-related central nervous system diseases (CNS-D) in recent years are sparse. METHODS: Between 1996 and 2007, adult subjects without previous CNS-D within a large UK cohort were included (n=30,954). CNS-D were HIV encephalopathy (HIVe), progressive multifocal leucoencephalopathy (PML), cerebral toxoplasmosis (TOXO) and cryptococcal meningitis (CRYP). Associations between demographic, clinical and laboratory parameters with incidence and survival of CNS-D were evaluated using Poisson regression analysis and Kaplan-Meier techniques. RESULTS: Six hundred and thirteen new CNS-D occurred in 574 subjects (HIVe:187, PML:113, TOXO:184, CRYP:129). Incidence of all CNS-D declined from 13.1 per 1000 PY in 1996/1997 to 1.0 per 1000 PY in 2006/2007 (P=0.0001). Current CD4+ cell count below 200 cells/ul and plasma HIV RNA above 100,000 copies/ml were independently associated with the development of CNS-D. Calendar year 1996/1997, older age, prior AIDS diagnosis and PML diagnosis were significantly associated with shorter survival. CONCLUSIONS: An ongoing decline in the incidence of CNS-D has been observed in very recent years. Mortality following such a diagnosis remains high.

Factors influencing lopinavir and atazanavir plasma concentration.

BACKGROUND: The protease inhibitors lopinavir and atazanavir are both recommended for treatment of HIV-infected patients. Considerable inter-individual variability in plasma concentration has been observed for both drugs. The aim of this study was to evaluate which demographic factors and concomitant drugs are associated with lopinavir and atazanavir plasma concentration. METHODS: Data from the Liverpool TDM (therapeutic drug monitoring) Registry were linked with the UK Collaborative HIV Cohort (CHIC) study. For each patient, the first measurement of lopinavir (twice daily) or atazanavir [once daily, ritonavir boosted (/r) or unboosted] plasma concentration was included. Linear regression was used to evaluate the association of dose, gender, age, weight, ethnicity and concomitant antiretroviral drugs or rifabutin with log-transformed drug concentration, adjusted for time since last intake. RESULTS: Data from 439 patients on lopinavir (69% 400 mg/r, 31% 533 mg/r; 3% concomitant rifabutin) and 313 on atazanavir (60% 300 mg/r, 32% 400 mg/r, 8% 400 mg) were included. Multivariable models revealed the following predictors for lopinavir concentration: weight (11% decrease per additional 10 kg; P = 0.001); dose (25% increase for 533 mg/r; P = 0.024); and rifabutin (116% increase; P < 0.001). For atazanavir the predictors were dose (compared with 300 mg/r: 40% increase for 400 mg/r, 67% decrease for 400 mg; overall P < 0.001) and efavirenz (32% decrease; P = 0.016) but not tenofovir (P = 0.54). CONCLUSIONS: This analysis confirms that efavirenz decreases atazanavir concentrations, and there was a negative association of weight and lopinavir concentrations. The strong impact of rifabutin on lopinavir concentration should be studied further.

Tuberculosis among people with HIV infection in the United Kingdom: opportunities for prevention?

OBJECTIVE: To investigate the incidence of, and risk factors for, tuberculosis among HIV clinic attendees in the United Kingdom. DESIGN AND METHODS: Observational cohort study of 27 868 individuals in the United Kingdom Collaborative HIV Cohort collaboration, 1996-2005. RESULTS: Among individuals not taking combination antiretroviral therapy (cART), tuberculosis incidence was considerably higher among individuals of black African vs. white or other ethnicities {incidence rates 9.9 [95% confidence intervals (CIs) 7.2, 12.6], 2.5 [95% CI 1.8, 3.0] and 4.4 [95% CI 2.7, 6.0] episodes per 1000 person-years, respectively}. Tuberculosis incidence decreased with time after starting cART; among black Africans, incidence was consistently higher and remained substantial (5.3 per 1000 person-years) at 24 months and longer after starting cART. The strongest independent risk factors for tuberculosis after cART start were most recent CD4 cell count: adjusted rate ratios (aRR) 10.65 (95% CI 6.11, 18.57), 3.40 (95% CI 2.05, 5.65), 1.77 (95% CI 1.06, 2.96) and 1.84 (95% CI 1.09, 3.12) for individuals with CD4 cell counts less than 50, 50-199, 200-349 and 350-499 cells/microl, respectively, compared with at least 500 cells/microl; and black African vs. white ethnicity [aRR 2.93 (95% CI 1.89, 4.54)]. HIV risk group, shorter time on cART, later calendar period and unsuppressed viral load were also independently associated with incident tuberculosis. CONCLUSIONS: Tuberculosis incidence among people attending UK HIV clinics is substantial, particularly among those with non-white ethnicity and low CD4 cell counts, even after starting cART. Earlier HIV diagnosis is needed in order to implement interventions to prevent tuberculosis; tuberculosis preventive therapy should be considered in addition to cART.

Virological response to initial antiretroviral regimens containing abacavir or tenofovir.

Patients with a baseline viral load >100,000 copies/mL receiving abacavir (ABC) as part of the nucleoside-backbone component of their first highly active antiretroviral therapy (HAART) regimen have been reported to have a greater failure rate than those receiving tenofovir (TDF). We analyzed short-term outcomes of the use of HAART combinations that included ABC or TDF. The mean 2-8-week change in viral load was calculated using linear regression. In total, 1136 patients started ABC, and 412 started TDF. After adjustment for baseline viral load and other factors, there was no difference in the change in viral load between the patients who started ABC and those who started TDF (0.03 [95% confidence interval, -0.07 to 0.12]) log copies/mL; P = .59). Furthermore, there was no evidence that this effect differed according to baseline viral load (P = .88 for the interaction between pre-HAART viral load and nucleoside started). Likewise, there was no difference in rates of virological failure between the 2 drugs at 24-48 weeks after starting HAART.

Is 1 alanine transaminase >200 IU enough to define an alanine transaminase flare in HIV-infected populations? A new definition derived from a large cohort study.

OBJECTIVES: Recent studies have suggested that highly active antiretroviral therapy may lead to rises in alanine transaminase (ALT) among HIV-infected patients. However, the definition of an ALT flare is arbitrary and the extent to which such increases represent normal fluctuations has not been explored. METHODS: Using data from untreated, hepatitis B virus/hepatitis C virus-negative, HIV-infected patients, we derived a definition for an ALT flare by exploring a series of ALT thresholds (from 100 to 200 IU/L). The resulting definition (2 consecutive ALTs > 200 measured >2 weeks apart) was applied to all patients in the UK Collaborative HIV Cohort (CHIC) Study, and Poisson regression was used to identify factors associated with ALT flares. RESULTS: Five hundred and twenty six of 12,206 eligible patients (4.3%) had > or =1 ALT flare, resulting in a total of 615 episodes of ALT flares. The overall rate of an ALT flare was 1.19 (95% confidence interval: 1.10 to 1.28) per 100 person-years. Higher risk of ALT flare was associated with lower CD4 counts, detectable viral loads, being under follow-up in earlier calendar years, prior clinical AIDS, receipt of nevirapine either with didanosine/stavudine or without didanosine/stavudine, receipt of ritonavir, detectable anti-hepatitis C virus, and detectable hepatitis B surface antigen. CONCLUSIONS: Associations between known risk factors may be under/over estimated if using single values, that is, 1 ALT > 200, to define ALT flares. We recommend studies to use a more stringent measure and suggest our derived definition of an ALT flare.

Factors influencing efavirenz and nevirapine plasma concentration: effect of ethnicity, weight and co-medication.

BACKGROUND: The aim of this study was to examine factors influencing plasma concentration of efavirenz and nevirapine. METHODS: Data from the Liverpool Therapeutic Drug Monitoring (TDM) registry were linked with the UK Collaborative HIV Cohort (CHIC) Study. For each patient, the first measurement of efavirenz (600 or 800 mg/day) or nevirapine (400 mg/day) plasma concentration was included. Linear regression was used to evaluate the association of dose, gender, age, weight, ethnicity and concomitant antiretroviral drugs or rifampicin with log-transformed drug concentration, adjusted for time since last intake. RESULTS: Data from 339 patients on efavirenz (34% black, 17% rifampicin) and 179 on nevirapine (27% black, 6% rifampicin) were included. Multivariable models revealed the following predictors for efavirenz concentration: black ethnicity (59% higher; P<0.001), weight (10% lower per additional 10 kg; P=0.002), 800 mg/day (52% higher; P=0.027), rifampicin (35% lower; P=0.039), and zidovudine (25% lower; P=0.010). Notably, without adjustment for other factors, patients on rifampicin had 48% higher efavirenz concentration, as these patients were mostly black and on 800 mg/day. For nevirapine the predictors were black ethnicity (39% higher; P=0.002), rifampicin (40% lower; P=0.002), protease inhibitor (28% higher; P=0.008) and tenofovir (22% higher; P=0.024). CONCLUSIONS: We observed clear associations between ethnicity and concentrations of nevirapine and efavirenz. Our analyses confirm that concomitant rifampicin substantially decreases concentration of both efavirenz and nevirapine; however, for efavirenz this effect was more than counterbalanced by the effect of ethnicity and increased efavirenz dose. There was also an additional impact of weight, which should be considered when determining optimal dosage. Other associations from our analysis (between tenofovir or protease inhibitor and nevirapine, and zidovudine and efavirenz), require confirmation in formal pharmacokinetic studies.

Predictors of renal outcome in HIV-associated nephropathy.

BACKGROUND: Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is an important cause of end-stage renal disease among African American patients. This study was performed to study the epidemiology of HIVAN in a predominantly black African population and the impact of highly active antiretroviral therapy and other factors on the development of end-stage renal disease. METHODS: We retrospectively identified all patients with HIVAN, defined by biopsy or strict clinical criteria, in 8 clinics in the United Kingdom. Baseline renal function, HIV parameters, renal pathological index of chronic damage, and responses to highly active antiretroviral therapy were analyzed, and factors associated with adverse renal outcome were identified. RESULTS: From 1998 through 2004, we studied 16,834 patients, 61 of whom had HIVAN. HIVAN prevalence in black patients was 0.93%, and HIVAN incidence in those without renal disease at baseline was 0.61 per 1000 person-years. After a median of 4.2 years, 34 patients (56%) had developed end-stage renal disease. There were no significant differences in renal function and HIV parameters at baseline, time to initiation of highly active antiretroviral therapy, and rates of HIV RNA suppression between the 20 patients who developed end-stage renal disease >3 months after receiving the HIVAN diagnosis and the 23 patients who maintained stable renal function. However, the index of chronic damage score was significantly higher in those who developed end-stage renal disease (P < .001), and an index of chronic damage score >75 was associated with shorter renal survival (P < .001). CONCLUSIONS: Whereas overall patient survival suggested an important benefit of highly active antiretroviral therapy, no additional renal benefit of early initiation of highly active antiretroviral therapy or viral suppression could be demonstrated in this large cohort of patients with established HIVAN. Severity of chronic kidney damage, as quantified by biopsy, was the strongest predictor of renal outcome.