Janet Nicotera

Early Versus Standard Antiretroviral Therapy for HIV Infected Adults in Haiti

BACKGROUND For adults with human immunodeficiency virus (HIV) infection who have CD4+ T-cell counts that are greater than 200 and less than 350 per cubic millimeter and who live in areas with limited resources, the optimal time to initiate antiretroviral therapy remains uncertain. METHODS We conducted a randomized, open-label trial of early initiation of antiretroviral therapy, as compared with the standard timing for initiation of therapy, among HIV-infected adults in Haiti who had a confirmed CD4+ T-cell count that was greater than 200 and less than 350 per cubic millimeter at baseline and no history of an acquired immunodeficiency syndrome (AIDS) illness. The primary study end point was survival. The early-treatment group began taking zidovudine, lamivudine, and efavirenz therapy within 2 weeks after enrollment. The standard-treatment group started the same regimen of antiretroviral therapy when their CD4+ T-cell count fell to 200 per cubic millimeter or less or when clinical AIDS developed. Participants in both groups underwent monthly follow-up assessments and received isoniazid and trimethoprim-sulfamethoxazole prophylaxis with nutritional support. RESULTS Between 2005 and 2008, a total of 816 participants--408 per group--were enrolled and were followed for a median of 21 months. The CD4+ T-cell count at enrollment was approximately 280 per cubic millimeter in both groups. There were 23 deaths in the standard-treatment group, as compared with 6 in the early-treatment group (hazard ratio with standard treatment, 4.0; 95% confidence interval [CI], 1.6 to 9.8; P=0.001). There were 36 incident cases of tuberculosis in the standard-treatment group, as compared with 18 in the early-treatment group (hazard ratio, 2.0; 95% CI, 1.2 to 3.6; P=0.01). CONCLUSIONS Early initiation of antiretroviral therapy decreased the rates of death and incident tuberculosis. Access to antiretroviral therapy should be expanded to include all HIV-infected adults who have CD4+ T-cell counts of less than 350 per cubic millimeter, including those who live in areas with limited resources. (ClinicalTrials.gov number, NCT00120510.)

Evidence of a Source of HIV Type 1 within the Central Nervous System by Ultraintensive Sampling of Cerebrospinal Fluid and Plasma

Defining the source of HIV-1 RNA in cerebrospinal fluid (CSF) will facilitate studies of treatment efficacy in the brain. Four antiretroviral drug-naive adults underwent two 48-hr ultraintensive CSF sampling procedures, once at baseline and again beginning on day 4 after initiating three-drug therapy with stavudine, lamivudine, and nelfinavir. At baseline, constant CSF HIV-1 RNA concentrations were maintained by daily entry of at least 10(4) to 10(6) HIV-1 RNA copies into CSF. Change from baseline to day 5 ranged from -0.38 to -1.18 log(10) HIV-1 RNA copies/ml in CSF, and from -0.80 to -1.33 log(10) HIV-1 RNA copies/ml in plasma, with no correlation between CSF and plasma changes. There was no evidence of genotypic or phenotypic viral resistance in either CSF or plasma. With regard to pharmacokinetics, mean CSF-to-plasma area-under-the-curve (AUC) ratios were 38.9% for stavudine and 15.3% for lamivudine. Nelfinavir and its active M8 metabolite could not be accurately quantified in CSF, although plasma M8 peak level and AUC(0-8hr) correlated with CSF HIV-1 RNA decline. This study supports the utility of ultraintensive CSF sampling for studying HIV-1 pathogenesis and therapy in the CNS, and provides strong evidence that HIV-1 RNA in CSF arises, at least in part, from a source other than plasma.

Steady-state pharmacokinetics of indinavir in cerebrospinal fluid and plasma among adults with human immunodeficiency virus type 1 infection

To characterize steady‐state indinavir pharmacokinetics in cerebrospinal fluid and plasma, 8 adults infected with human immunodeficiency virus underwent intensive cerebrospinal fluid sampling while receiving indinavir (800 mg every 8 hours) plus nucleoside reverse transcriptase inhibitors. Nine and 11 serial cerebrospinal fluid and plasma samples, respectively, were obtained from each subject. Free indinavir accounted for 94.3% of the drug in cerebrospinal fluid and 41.7% in plasma. Mean values of cerebrospinal fluid peak concentration, concentration at 8 hours, and area under the concentration‐time profile calculated over the interval 0 to 8 hours [AUC(0‐8)] for free indinavir were 294 nmol/L, 122 nmol/L, and 1616 nmol/L · h, respectively. The cerebrospinal fluid‐to‐plasma AUC(0‐8) ratio for free indinavir was 14.7% ± 2.6% and did not correlate with indexes of blood‐brain barrier integrity or intrathecal immune activation. Indinavir achieves levels in cerebrospinal fluid that should contribute to control of human immunodeficiency virus type 1 replication in this compartment. The cerebrospinal fluid‐to‐plasma AUC(0‐8) ratio suggests clearance mechanisms in addition to passive diffusion across the blood‐cerebrospinal fluid barrier, perhaps by P‐glycoprotein–mediated efflux. (Clin Pharmacol Ther 2000;68:367‐74.)

Effects of ritonavir on indinavir pharmacokinetics in cerebrospinal fluid and plasma

ABSTRACT Therapeutic control of human immunodeficiency virus type 1 (HIV-1) in peripheral compartments does not assure control in the central nervous system. Inadequate drug penetration may provide a sanctuary from which resistant virus can emerge or allow development of psychomotor abnormalities. To characterize the effect of ritonavir on indinavir disposition into cerebrospinal fluid, seven HIV-infected adults underwent intensive sampling at steady-state while receiving twice-daily indinavir (800 mg) and ritonavir (100 mg). Serial cerebrospinal fluid and plasma samples were obtained at 10 time points from each subject. Free indinavir accounted for 98.6% of drug in cerebrospinal fluid and 55.9% in plasma. Mean cerebrospinal fluid Cmax, Cmin, and area under the concentration-time curve from 0 to 12 h (AUC0-12) values for free indinavir were 735 nM, 280 nM, and 6,502 nM h−1, respectively, and the free levels exceeded 100 nM in every sample. The cerebrospinal fluid/plasma AUC0-12 ratio for free indinavir was 17.5% ± 6.4%. This ratio was remarkably similar to results obtained in a previous study in which subjects received indinavir without ritonavir, indicating that ritonavir did not have a substantial direct effect on the barrier to indinavir penetration into cerebrospinal fluid. Low-dose ritonavir increases cerebrospinal fluid indinavir concentrations substantially more than 800 mg of indinavir given thrice daily without concomitant ritonavir, despite a lower total daily indinavir dose.

Pharmacokinetics of Acyclovir and Its Metabolites in Cerebrospinal Fluid and Systemic Circulation after Administration of High-Dose Valacyclovir in Subjects with Normal and Impaired Renal Function

ABSTRACT Valacyclovir, the l-valyl ester prodrug of acyclovir (ACV), is widely prescribed to treat infections caused by varicella-zoster virus or herpes simplex virus. Rarely, treatment is complicated by reversible neuropsychiatric symptoms. By mechanisms not fully understood, this occurs more frequently in the setting of renal impairment. We characterized the steady-state pharmacokinetics of ACV and its metabolites 9-[(carboxymethoxy)methyl]guanine (CMMG) and 8-hydroxy-acyclovir (8-OH-ACV) in cerebrospinal fluid (CSF) and the systemic circulation. We administered multiple doses of high-dose valacyclovir to 6 subjects with normal renal function and 3 subjects with chronic renal impairment (creatinine clearance [CrCl], ∼15 to 30 ml/min). Dosages were 2,000 mg every 6 h and 1,500 mg every 12 h, respectively. Indwelling intrathecal catheters allowed serial CSF sampling throughout the dosing interval. The average steady-state concentrations of acyclovir, CMMG, and 8-OH-ACV were greater in both the systemic circulation and the CSF among subjects with impaired renal function than among subjects with normal renal function. However, the CSF penetration of each analyte, reflected by the CSF-to-plasma area under the concentration-time curve over the 6- or 12-h dosing interval (AUCτ) ratio, did not differ based on renal function. Renal impairment does not alter the propensity for ACV or its metabolites to distribute to the CSF, but the higher concentrations in the systemic circulation, as a result of reduced elimination, are associated with proportionally higher concentrations in CSF.

Effects of nelfinavir and its M8 metabolite on lymphocyte P‐glycoprotein activity during antiretroviral therapy

The efflux pump P‐glycoprotein decreases drug penetration into cells and tissues. To determine whether nelfinavir or its metabolites inhibit P‐glycoprotein in lymphocytes from a healthy volunteer, whole blood cells from human immunodeficiency virus‐negative donors were incubated either in human plasma to which nelfinavir or its M8 metabolite were added ex vivo or in plasma from human immunodeficiency virus‐positive patients receiving nelfinavir. The 50% P‐glycoprotein inhibitory concentrations of purified nelfinavir and M8 were 10.9 μmol/L and 29.5 μmol/L, respectively, for CD4+ T cells and 19.3 μmol/L and >48 μmol/L, respectively, for CD8+ T cells. Significant inhibitory activity was present in plasma from 27 of 46 patients (59%) receiving nelfinavir. Plasma nelfinavir concentrations correlated with percent inhibition on CD4+ (ρ = 0.85, P < .0001) and CD8+ (ρ = 0.83, P < .0001) T cells. The M8 concentrations correlated weakly with both inhibition and nelfinavir concentrations. On the basis of our findings in lymphocytes from a healthy volunteer exposed to plasma from human immunodeficiency virus‐positive patients, we believe it is likely that CD4+ and CD8+ lymphocytes in patients receiving nelfinavir as therapy for human immunodeficiency virus may have P‐glycoprotein inhibited by plasma concentrations of nelfinavir.

Two phases of HIV RNA decay in CSF during initial days of multidrug therapy

Background: Defining cellular and tissue sources of HIV-1 in CSF is important for understanding disease pathogenesis and optimal therapies for HIV infection in the brain. Objective: To identify the time of maximal viral decay in CSF during the initial days of antiretroviral therapy. Methods: Serial CSF and plasma data were available from four adults who underwent ultraintensive CSF sampling for 48 hours at baseline and again beginning 72 hours after starting antiretroviral therapy. Regression lines were generated using HIV-1 RNA data from 17 on-treatment serial CSF samples obtained at 3-hour intervals. Viral RNA was quantified by Nuclisens® and Amplicor HIV-1 Monitor® assays. Results: Extrapolation of regression lines intersected baseline below actual baseline CSF HIV-1 RNA concentrations, indicating that virus decayed most rapidly on days 1 through 3 with half-lives of no more than 0.9 to 2.8 days. Half-lives on days 4 and 5 ranged from 1.3 to 4.9 days. Plasma data also showed early rapid decay. Conclusions: Multiple phases of viral decay suggest that virus in CSF originates from at least two sources during untreated, asymptomatic HIV-1 infection. The short half-life indicates that the primary source is CD4+ T cells. Sampling during days 1 through 3 and different stages of disease will better define sources of virus.

Attrition from HIV testing to antiretroviral therapy initiation among patients newly diagnosed with HIV in Haiti.

Objective:We report rates and risk factors for attrition in the first cohort of patients followed through all stages from HIV testing to antiretroviral therapy (ART) initiation. Design:Cohort study of all patients diagnosed with HIV between January and June 2009. Methods:We calculated the proportion of patients who completed CD4 cell counts and initiated ART or remained in pre-ART care during 2 years of follow-up and assessed predictors of attrition. Results:Of 1427 patients newly diagnosed with HIV, 680 (48%) either initiated ART or were retained in pre-ART care for the subsequent 2 years. One thousand eighty-three patients (76%) received a CD4 cell count, and 973 (90%) returned for result; 297 (31%) had CD4 cell count <200 cells per microliter, and of these, 256 (86%) initiated ART. Among 429 patients with CD4 >350 cells per microliter, 215 (50%) started ART or were retained in pre-ART care. Active tuberculosis was associated with not only lower odds of attrition before CD4 cell count [odds ratio (OR): 0.08; 95% confidence interval (CI): 0.03 to 0.25] but also higher odds of attrition before ART initiation (OR: 2.46; 95% CI: 1.29 to 4.71). Lower annual income (⩽US

Comparison of Roche MONITOR and Organon Teknika NucliSens Assays To Quantify Human Immunodeficiency Virus Type 1 RNA in Cerebrospinal Fluid

125) was associated with higher odds of attrition before CD4 cell count (OR: 1.65; 95% CI: 1.25 to 2.19) and before ART initiation among those with CD4 cell count >350 cells per microliter (OR: 1.74; 95% CI: 1.20 to 2.52). After tracking patients through a national database, the retention rate increased to only 57%. Conclusions:Fewer than half of patients newly diagnosed with HIV initiate ART or remain in pre-ART care for 2 years in a clinic providing comprehensive services. Additional efforts to improve retention in pre-ART are critically needed.

Reflections on the Initial Multinational Response to the Earthquake in Haiti

ABSTRACT We compared Roche MONITOR and Organon Teknika NucliSens assays for human immunodeficiency virus type 1 (HIV-1) RNA in cerebrospinal fluid (CSF). Results of 282 assays were highly correlated (r = 0.826), with MONITOR values being 0.29 ± 0.4 log10copies/ml (mean ± standard deviation) values. Both assays can reliably quantify HIV-1 RNA in CSF.