bImmune response stimulation to prevent infection progression may be an adjuvant to antimicrobial treatment. Lysophosphatidylcholine (LPC) is an immunomodulator involved in immune cell recruitment and activation. In this study, we aimed to evaluate the efficacy of LPC in combination with colistin, tigecycline, or imipenem in experimental murine models of peritoneal sepsis and pneumonia. We used Acinetobacter baumannii strain Ab9, which is susceptible to colistin, tigecycline, and imipenem, and multidrug-resistant strain Ab186, which is susceptible to colistin and resistant to tigecycline and imipenem. Pharmacokinetic and pharmacodynamic parameters for colistin, tigecycline, and imipenem and the 100% minimal lethal dose (MLD 100 ) were determined for both strains. The therapeutic efficacies of LPC, colistin (60 mg/kg of body weight/day), tigecycline (10 mg/kg/day), and imipenem (180 mg/kg/day), alone or in combination, were assessed against Ab9 and Ab186 at the MLD 100 in murine peritoneal sepsis and pneumonia models. The levels of pro-and anti-inflammatory cytokines, i.e., tumor necrosis factor alpha (TNF-␣) and interleukin-10 (IL-10), were determined by enzyme-linked immunosorbent assay (ELISA) for the same experimental models after inoculating mice with the MLD of both strains. LPC in combination with colistin, tigecycline, or imipenem markedly enhanced the bacterial clearance of Ab9 and Ab186 from the spleen and lungs and reduced bacteremia and mouse mortality rates (P < 0.05) compared with those for colistin, tigecycline, and imipenem monotherapies. Moreover, at 4 h post-bacterial infection, Ab9 induced higher TNF-␣ and lower IL-10 levels than those with Ab186 (4 g/ml versus 3 g/ml [P < 0.05] and 2 g/ml versus 3.4 g/ml [P < 0.05], respectively). LPC treatment combined with colistin, tigecycline, or imipenem modestly reduced the severity of infection by A. baumannii strains with different resistance phenotypes compared to LPC monotherapy in both experimental models.A cinetobacter baumannii is a Gram-negative coccobacillus with high clinical relevance due to the different severe nosocomial infections that it causes, mainly in intensive care units, and its capacity to develop resistance to most of the antimicrobial agents used in clinical practice (1).A multidrug resistance pattern is commonly observed for A. baumannii isolates, raising the threat of impossible-to-treat infections (2). These multidrug-resistant (MDR) isolates are generally susceptible to polymyxins (colistin and polymyxin B) and resistant to imipenem and tigecycline (3, 4). The limited antimicrobial alternatives for the treatment of severe infections by MDR A. baumannii make the search for other therapeutic options urgent. Polymyxins have been used as a last resort to treat infections by MDR A. baumannii. In humans, suboptimal and optimal doses of colistin to treat ventilator-associated pneumonia due to MDR A. baumannii prevent mortality in only 38.1% and 62.5% of cases, respectively (5, 6). Recently, in a clinical trial at our hospital, treatm...

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The effect of simultaneous plasma concentrations of pegylated interferon-alpha-2a (pegIFN-alpha-2a) and ribavirin (Rbv) on viral response has not been addressed to date. Hepatitis C virus (HCV)/human immunodeficiency virus (HIV)-coinfected patients received pegIFN-alpha-2a and Rbv under routine clinical care conditions. Plasma concentrations of the two drugs were measured using enzyme-linked immunosorbent assay and high-performance liquid chromatography after 2, 4, 8, and 12 weeks and at the end of the treatment period (24-48 weeks, according to HCV genotype and treatment duration). Large interindividual variability was observed in the plasma levels of both drugs. After multivariate analysis, only HCV genotype 3, low HCV-RNA levels, and pegIFN-alpha-2a exposure remained as independent factors associated with sustained viral response (SVR). The probability of attaining an SVR in HCV genotypes 1 and 4 was more than three to four times higher in patients with pegIFN-alpha-2a levels above the selected cutoff point. Early therapeutic drug monitoring of pegIFN-alpha-2a levels could be beneficial in improving current treatment outcomes.

There is significant intra-and intersubject variability in lopinavir (LPV) plasma concentrations after standard dosing; thus, this prospective study was conducted to determine whether low plasma LPV concentrations could be associated with virological outcome throughout lopinavir-ritonavir maintenance monotherapy (mtLPVr) in the clinical practice setting. If this hypothesis would be confirmed, LPV drug monitoring could improve the efficacy of mtLPVr regimens. Patients with previous virological failure (VF) on protease inhibitor-based regimens were also included if the genotypic resistance tests showed no major resistance mutation associated with reduced susceptibility to lopinavir-ritonavir. VF was defined as 2 consecutive determinations of HIV RNA levels of >200 copies/ml. Efficacy was analyzed by per-protocol analysis. Plasma LPV trough concentrations were measured by high-performance liquid chromatography using a UV detector. A total of 127 patients were included (22% with previous failure on protease inhibitors). After 96 weeks, the efficacy rate was 82.3% (95% confidence interval [CI 95 There is significant controversy regarding ritonavir-boosted protease inhibitor (PI) monotherapy as a maintenance therapeutic strategy (1-5). Notwithstanding, a considerable proportion of patients maintained an undetectable viremia on lopinavirritonavir maintenance monotherapy (mtLPVr) and could benefit from a simpler regimen without nucleoside analogues or other antiretroviral drugs. Moreover, lack of adherence has been indicated as the main reason for virological failure (VF) in different studies (6-13).Moreover, there is significant intra-and intersubject variability in LPV plasma concentrations after standard dosing, determined largely by variability in drug absorption, cytochrome P450 metabolism, plasma protein binding, and drug transporter activity, which may affect the disposition of the drug (14, 15). As LPV plasma concentrations and the genotype inhibitory quotient have been related to virological efficacy in experienced patients on LPVr-based regimens (16)(17)(18)(19), in this study, we tested whether low plasma LPV trough concentrations contribute to VF throughout the mtLPVr treatment period. The confirmation of this hypothesis would demonstrate that LPV therapeutic drug monitoring could be useful in improving the efficacy of LPV when prescribed as a monotherapy. MATERIALS AND METHODSStudy population and design. From April 2009 to April 2010, adult HIV-1-infected patients who started a regimen of mtLPVr at our outpatient clinic were consecutively included in this observational, prospective, open-label study. The LPVr dosing regimen (400 mg of LPV and 100 mg of ritonavir twice daily or 800 mg-200 mg once daily) was selected by the patients' physicians. All subjects had plasma HIV RNA levels of Ͻ50 copies/ml for at least 6 months. Patients with VF while on a PI-containing regimen were also included in the study when genotypic resistance tests showed no major or Յ3 minor resistance mutations associated with reduced...

The results provide evidence of similar elvitegravir and darunavir C 24 concentrations when these drugs are co-administered as co-formulated elvitegravir, cobicistat, emtricitabine and tenofovir disoproxil fumarate plus 800 mg darunavir or dosed separately.

The DRV Cmin values are related to viral control during mtDRV/rtv, but therapeutic drug monitoring cannot be recommended routinely as a precise cutoff point is unknown. Adherence is a key success factor on this regimen.

Studies on the association between the peginterferon-α and ribavirin levels and sustained virological response (SVR) have shown yielded conflicting results, but most of them were performed before the influence of IL28B polymorphisms was known. Our aim was to assess the effects of peginterferon-α 2a and ribavirin plasma levels on viral kinetics and SVR in hepatitis C virus genotype 1 HCV-1/HIV-co-infected patients according to IL28B genotype. This was a cohort study of HCV-1/HIV-co-infected patients who were HCV-treatment naïve and for whom the efficacy of peginterferon-α 2a plus ribavirin was evaluated by per-protocol analysis. The peginterferon-α 2a and ribavirin levels were measured by ELISA and HPLC-UV, respectively. The relationships among host and viral factors, the trough drugs levels and virological responses were analysed by multivariate regression analyses. A total of 131 Caucasian patients were included (cirrhosis:38.9%). Overall, SVR rate was 39.6%. In patients with CC IL28B genotype, SVR was related neither to peginterferon-α 2a nor to ribavirin plasma levels, while higher levels of both drugs were the only variables independently associated with SVR in individuals with CT/TT IL28B genotypes (OR, 5.02; CI95 , 1.45-17.1; P = 0.001 and 4.0; CI95 , 1.08-14.7; P = 0.038, respectively). Moreover, faster viral declines were observed in CT/TT patients when pegIFN-α 2a and ribavirin plasma levels were greater than 3400 pg/mL and 1.6 μg/mL, respectively. In contrast to the results for CC patients, the results in patients carrying the unfavourable CT/TT IL28B genotypes showed that plasma levels of both drugs have significant effects on viral kinetics and SVR.