Ritonavir-boosted atazanavir-lopinavir combination: a pharmacokinetic interaction study of total, unbound plasma and cellular exposures.

OBJECTIVES: To assess potential pharmacokinetic (PK) interactions between atazanavir (ATV, 300 mg, once daily) and lopinavir (LPV, 400 mg, twice daily), both boosted by ritonavir (RTV, 100 mg). DESIGN: Two-parallel groups, addition of LPV in patients receiving ATV (n=6), and addition of ATV in patients receiving LPV (n=7), with before/after comparisons. METHODS: Each group had two complete PK profiles before and 2 weeks after the addition of the second protease inhibitor (PI). Total plasma concentrations (Ctot) were analysed by HPLC-UV and unbound plasma concentrations (Cu) and cellular concentrations (Ccell) were analysed by LC-MS/MS. Plasma and cellular PK parameters were also calculated. Unbound and cellular fractions were expressed as Cu/Ctot and Ccell/Ctot ratio. Data were analysed by paired Student t-test on log values; correlations between Ccell, Cu and Ctot were explored by log-log linear regression. RESULTS: Adding LPV to ATV did not influence the plasma and cellular PK parameters of ATV. Adding ATV to LPV was associated with a decrease in LPV concentrations (by 16% for area under the time-concentration curve, maximum concentration and trough concentration, NS; and by 35% for Cmin, P=0.04). The RTV PK parameters remained unmodified. The Ccell/Ctot and Cu/Ctot ratio was unaffected by the addition of the second PI and remained stable throughout dosing interval. Good correlations were observed between Ccell, Cu and Ctot for each drug. No relevant toxicity was observed. CONCLUSIONS: Adding LPV to ATV did not influence the plasma and cellular PK parameters of ATV. Adding ATV to LPV caused a limited decrease in LPV concentrations. The clinical significance of this decrease is unknown and warrants further investigation to determine the need for tailoring LPV dosage in selected cases.

Long-term close follow-up of chorioretinal lesions in presumed ocular tuberculosis.

PURPOSE: To evaluate the long-term outcome (up to 7 years) of presumed ocular tuberculosis (TB) when the therapeutic decision was based on WHO guidelines. METHODS: Twelve out of 654 new uveitic patients (1998-2004) presented with choroiditis and positive tuberculosis skin test (TST) (skin lesion diameter >15 mm). Therapy was administered according to WHO recommendations after ophthalmic and systemic investigation. The area size of ocular lesions at presentation and after therapy, measured on fluorescein and indocyanine green angiographies, was considered the primary outcome. Relapse of choroiditis was considered a secondary outcome. The T-SPOT TB test was performed when it became available. RESULTS: Visual acuity significantly improved after therapy (p=0.0357). The mean total surface of fluorescein lesions at entry was 44.8 ± 20.9 (arbitrary units) and decreased to 32.5 ± 16.9 after therapy (p=0.0165). The mean total surface of indocyanine green lesions at entry was 24.5 ± 13.3 and decreased to 10.8 ± 5.4 after therapy (p=0.0631). The T-SPOT TB revealed 2 false TST-positive results. The mean follow-up was 4.5 ± 1.5 years. Two relapses out of 10 confirmed ocular TB was observed after complete lesion healing, 2.5 years and 4.5 years after therapy, respectively. CONCLUSIONS: A decrease of ocular lesion mean size and a mean improvement of VA were observed after antituberculous therapy. Our long-term follow-up of chorioretinal lesions demonstrated relapse of ocular tuberculosis in 10% of patients with confirmed ocular TB, despite complete initial retinal scarring.

HIV-1 drug resistance transmission networks in southwest Switzerland.

To determine viral subtypes and resistance mutations to antiretroviral treatment (ART) in untreated HIV-1 acutely infected subjects from Southwest Switzerland. Clinical samples were obtained from the HIV primary infection cohort from Lausanne. Briefly, pol gene was amplified by nested PCR and sequenced to generate a 1 kb sequence spanning protease and reverse transcriptase key protein regions. Nucleotide sequences were used to assess viral genotype and ART resistance mutations. Blood specimens and medical information were obtained from 30 patients. Main viral subtypes corresponded to clade B, CRF02_AG, and F1. Resistant mutations to PIs consisted of L10V and accessory mutations 16E and 60E present in all F1 clades. The NNRTI major resistant mutation 103N was detected in all F1 viruses and in other 2 clades. Additionally, we identified F1 sequences from other 6 HIV infected and untreated individuals from Southwest Switzerland, harboring nucleotide motifs and resistance mutations to ART as observed in the F1 strains from the cohort. These data reveal a high transmission rate (16.6%) for NNRTI resistant mutation 103N in a cohort of HIV acute infection. Three of the 5 resistant strains were F1 clades closely related to other F1 isolates from HIV-1 infection untreated patients also coming from Southwest Switzerland. Overall, we provide strong evidence towards an HIV-1 resistant transmission network in Southwest Switzerland. These findings have relevant implications for the local molecular mapping of HIV-1 and future ART surveillance studies in the region.

EV01: a phase I trial in healthy HIV negative volunteers to evaluate a clade C HIV vaccine, NYVAC-C undertaken by the EuroVacc Consortium.

NYVAC-C (vP2010), a recombinant vector expressing HIV subtype C gag, pol, env and nef antigens, was tested in a phase I study in healthy, HIV negative volunteers in London and Lausanne. Twenty-four participants were randomised to receive NYVAC-C (20) or matching placebo (4) at weeks 0 and 4, and assessed for safety and immunogenicity over 48 weeks. There were no serious adverse events, and no clinical or laboratory abnormalities or other events that led to withdrawal, interruption or dose reduction of the NYVAC-C/placebo. Half of the 10 assessed responded in the ELISpot assay under stringent criteria, which informed the sample size for a DNA-NYVAC-C comparison to NYVAC-C alone.