Marked increase in etravirine and saquinavir plasma concentrations during atovaquone/proguanil prophylaxis

The case of a 32-year-old Caucasian female with multi-drug resistant HIV-1 subtype B infection treated with a salvage regimen including maraviroc, raltegravir, etravirine and unboosted saquinavir who started atovaquone/proguanil prophylaxis, is reported. The potential interactions between atovaquone/proguanil and these anti-retroviral drugs are investigated. Pharmacokinetic analyses documented a marked increase in etravirine and saquinavir plasma concentrations (+55% and +274%, respectively), but not in raltegravir and maraviroc plasma concentrations. The evidence that atovaquone/proguanil significantly interacts with etravirine and saquinavir, but not with raltegravir and maraviroc, suggests that the mechanism of interaction is related to cytochrome P450

Early expansion of myeloid-derived suppressor cells inhibits SARS-CoV-2 specific T-cell response and may predict fatal COVID-19 outcome

The immunological mechanisms underlying the clinical presentation of SARS-CoV-2 infection and those influencing the disease outcome remain to be defined. Myeloid-derived suppressor cells (MDSC) have been described to be highly increased during COVID-19, however, their role remains elusive. We performed an in depth analysis of MDSC in 128 SARS-CoV-2 infected patients. Polymorphonuclear (PMN)-MDSC expanded during COVID-19, in particular in patients who required intensive care treatments, and correlated with IL-1β, IL-6, IL-8, and TNF-α plasma levels. PMN-MDSC inhibited T-cells IFN-γ production upon SARS-CoV-2 peptides stimulation, through TGF-β- and iNOS-mediated mechanisms, possibly contrasting virus elimination. Accordingly, a multivariate regression analysis found a strong association between PMN-MDSC percentage and fatal outcome of the disease. The PMN-MDSC frequency was higher in non-survivors than survivors at the admission time, followed by a decreasing trend. Interestingly, this trend was associated with IL-6 increase in non-survivors but not in survivors. In conclusion, this study indicates PMN-MDSC as a novel factor in the pathogenesis of SARS-CoV2 infection, and open up to new therapeutic options

Analysis of single-nucleotide polymorphisms (SNPs) in human CYP3A4 and CYP3A5 genes: potential implications for the metabolism of HIV drugs

Background: Drug metabolism via the cytochrome P450 (CYP450) system has emerged as an important determinant in the occurrence of several drug interactions (adverse drug reactions, reduced pharmacological effect, drug toxicities). In particular, CYP3A4 and CYP3A5 (interacting with more than 60% of licensed drugs) exhibit the most individual variations of gene expression, mostly caused by single nucleotide polymorphisms (SNPs) within the regulatory region of the CYP3A4 and CYP3A5 genes which might affect the level of enzyme production. In this study, we sought to improve the performance of sensitive screening for CYP3A polymorphism detection in twenty HIV-1 infected patients undergoing lopinavir/ritonavir (LPV/r) monotherapy. Methods: The study was performed by an effective, easy and inexpensive home-made Polymerase Chain Reaction Direct Sequencing approach for analyzing CYP3A4 and CYP3A5 genes which can detect both reported and unreported genetic variants potentially associated with altered or decreased functions of CYP3A4 and CYP3A5 proteins. Proportions and tests of association were used. Results: Among the genetic variants considered, CYP3A4*1B (expression of altered function) was only found in 3 patients (15%) and CYP3A5*3 (expression of splicing defect) in 3 other patients (15%). CYP3A5*3 did not appear to be associated with decreased efficacy of LPV/r in any patient, since none of the patients carrying this variant showed virological rebound during LPV/r treatment or low levels of TDM. In contrast, low-level virological rebound was observed in one patient and a low TDM level was found in another; both were carrying CYP3A4*1B. Conclusions: Our method exhibited an overall efficiency of 100% (DNA amplification and sequencing in our group of patients). This may contribute to producing innovative results for better understanding the inter-genotypic variability in gene coding for CYP3A, and investigating SNPs as biological markers of individual response to drugs requiring metabolism via the cytochrome P450 system

CD3ζ down-modulation may explain Vγ9Vδ2 T lymphocyte anergy in HIV-infected patients

The aim of the present study was to explain the observed anergy of Vγ9Vδ2 T cells from human immunodeficiency virus (HIV)-positive patients. CD3ζ expression and interferon (IFN)-γ production by Vγ9Vδ2 T cells from HIV-positive and HIV-negative subjects were analyzed. We demonstrated that Vγ9Vδ2 T cells from HIV-infected patients expressed a lower level of CD3ζ than did Vγ9Vδ2 T cells from healthy donors. A direct correlation was found between CD3ζ expression and IFN-γ production capability by Vγ9Vδ2 T cells. However, activation of protein kinase C by phorbol myristate acetate is able to restore CD3ζ expression and IFN-γ production. Our findings may contribute to clarification of the molecular mechanisms of Vγ9Vδ2 T cell anergy found in HIV-positive patients. © 2008 by the Infectious Diseases Society of America. All rights reserved

Determination of telaprevir in plasma of HCV-infected patients by HPLC-UV

"Telaprevir is a direct acting antiviral agent, used with pegylated interferon and ribavirin for the management of chronic hepatitis C virus (HCV) genotype 1 infection, in patients not responding to therapy with pegylated interferon and ribavirin only. Although 75% of patients achieve a sustained virological response after treatment with telaprevir, adverse drug-drug interactions and undesirable events often occur. Therefore, telaprevir monitoring is pivotal to improve the management of HCV infection. Here, the first High-Performance Liquid Chromatography-Ultraviolet (HPLC-UV) method to quantify telaprevir in human plasma of HCV-genotype 1-infected patients is reported. The volume of the plasma sample was 700 L. This method involved automated solid-phase extraction with Oasis HLB Cartridge 1 cc (divinylbenzene and N-vinylpyrrolidone). The extracted samples were reconstituted with 150 L of 60\/40 water\/acetonitrile. Thirty microliters of these samples was injected into a HPLC-UV system, and the analytes were eluted on a X Terra((R)) RP18 column (250 mm x 4.6 mm i.d.) with a particle size of 5 m. The mobile phase (ammonium acetate buffer, 150 mM, pH 8.0, and methanol:acetonitrile 50:50) was delivered at 1.0 mL\/min with linear gradient elution. The total run time for a single analysis was 16 min; telaprevir was detected by UV at 276 and 286 nm. The calibration curve was linear from 312.5 to 20,000 ng\/mL (r(2) > 0.996). The absolute recovery of telaprevir ranged between 89 and 93% at concentrations of quality control samples of 800, 4,000, 8,000, and 16,000 ng\/mL. Both precision and accuracy were always <15%. The HPLC-UV method reported here: (i) has been validated, (ii) is currently applied to monitor telaprevir in plasma of HCV-infected patients, and (iii) appears useful in a routine laboratory