Noël Zahr

Efficacy of High-dose Nebulized Colistin in Ventilator-associated Pneumonia Caused by Multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii

Background:Colistin often remains the only active agent against multidrug-resistant Gram-negative pathogens. The aim of the study was to assess efficacy of nebulized colistin for treating ventilator-associated pneumonia (VAP) caused by multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii. Methods:One hundred and sixty-five patients with VAP caused by P. aeruginosa and A. baumannii were enrolled in a prospective, observational, and comparative study. The sensitive strain group included 122 patients with VAP caused by P. aeruginosa and A. baumannii susceptible to &bgr;-lactams, aminoglycosides, or quinolones and treated with intravenous antibiotics for 14 days. The multidrug-resistant strain group included 43 patients with VAP caused by multidrug-resistant P. aeruginosa and A. baumannii and treated with nebulized colistin (5 million international units every 8 h) either in monotherapy (n = 28) or combined to a 3-day intravenous aminoglycosides for 7–19 days. The primary endpoint was clinical cure rate. Aerosol was delivered using vibrating plate nebulizer. Results:After treatment, clinical cure rate was 66% in sensitive strain group and 67% in multidrug-resistant strain group (difference −1%, lower limit of 95% CI for difference −12.6%). Mortality was not different between groups (23 vs. 16%). Among 16 patients with persisting or recurrent P. aeruginosa infection, colistin minimum inhibitory concentration increased in two patients. Conclusion:Nebulization of high-dose colistin was effective to treat VAP caused by multidrug-resistant P. aeruginosa or A. baumannii. Its therapeutic effect was noninferior to intravenous &bgr;-lactams associated with aminoglycosides or quinolones for treating VAP caused by susceptible P. aeruginosa and A. baumannii.

Restoration of regulatory and effector T cell balance and B cell homeostasis in systemic lupus erythematosus patients through vitamin D supplementation.

IntroductionSystemic lupus erythematosus (SLE) is a T and B cell-dependent autoimmune disease characterized by the appearance of autoantibodies, a global regulatory T cells (Tregs) depletion and an increase in Th17 cells. Recent studies have shown the multifaceted immunomodulatory effects of vitamin D, notably the expansion of Tregs and the decrease of Th1 and Th17 cells. A significant correlation between higher disease activity and lower serum 25-hydroxyvitamin D levels [25(OH)D] was also shown.MethodsIn this prospective study, we evaluated the safety and the immunological effects of vitamin D supplementation (100 000 IU of cholecalciferol per week for 4 weeks, followed by 100 000 IU of cholecalciferol per month for 6 months.) in 20 SLE patients with hypovitaminosis D.ResultsSerum 25(OH)D levels dramatically increased under vitamin D supplementation from 18.7±6.7 at day 0 to 51.4±14.1 (p<0.001) at 2 months and 41.5±10.1 ng/mL (p<0.001) at 6 months. Vitamin D was well tolerated and induced a preferential increase of naïve CD4+ T cells, an increase of regulatory T cells and a decrease of effector Th1 and Th17 cells. Vitamin D also induced a decrease of memory B cells and anti-DNA antibodies. No modification of the prednisone dosage or initiation of new immunosuppressant agents was needed in all patients. We did not observe SLE flare during the 6 months follow-up period.ConclusionsThis preliminary study suggests the beneficial role of vitamin D in SLE patients and needs to be confirmed in randomized controlled trials.

Low Blood Concentration of Hydroxychloroquine in Patients With Refractory Cutaneous Lupus Erythematosus: A French Multicenter Prospective Study

OBJECTIVE To study the relation between blood concentration of hydroxychloroquine and the clinical efficacy of hydroxychloroquine sulfate in a series of patients with cutaneous lupus erythematosus (CLE). DESIGN Prospective multicenter study. A staff dermatologist blinded to blood hydroxychloroquine concentrations performed a standardized review of medical records and assessment of hydroxychloroquine efficacy in the following 3 categories: complete remission, partial remission (clearing of >50% of skin lesions), or treatment failure. Whole-blood samples were collected for measurement of blood hydroxychloroquine concentration. SETTING Fourteen French university hospitals. PATIENTS Three hundred consecutive patients with subacute or chronic CLE who had been treated with hydroxychloroquine for at least 3 months. MAIN OUTCOME MEASURES The statistical significance of correlation between blood hydroxychloroquine concentration and efficacy of hydroxychloroquine and the statistical associations in univariate and multivariate analyses of complete remission with several variables. RESULTS The study included 300 patients with discoid lupus erythematosus (n = 160), subacute CLE (n = 86), lupus erythematosus tumidus (n = 52), chilblain lupus (n = 26), and lupus panniculitis (n = 16); 38 of these patients had 2 or more associated forms. Median blood hydroxychloroquine concentration was significantly higher in patients with complete remission (910 [range, <50 to 3057] ng/mL) compared with partial remission (692 [<50 to 2843] ng/mL) and treatment failure (569 [<50 to 2242] ng/mL) (P = .007). In the multivariate analysis, complete remission was associated with higher blood hydroxychloroquine concentrations (P = .005) and the absence of discoid lesions (P = .004). Thirty patients (10.0%) had very low blood hydroxychloroquine concentrations (<200 ng/mL) and may be considered nonadherent to the treatment regimen. CONCLUSION Monitoring hydroxychloroquine blood concentrations might improve the management of refractory CLE.

The COMT Val158Met polymorphism affects the response to entacapone in Parkinson's disease: a randomized crossover clinical trial.

In Parkinson disease (PD), the selective C‐O‐methyltransferase (COMT) inhibitor entacapone prolongs the effect of levodopa on motor symptoms (ON time) by increasing its bioavailability. The COMT Val158Met polymorphism is equally distributed in PD patients and modulates COMT activity, which can be high (Val/Val, COMTHH), intermediate (Val/Met, COMTHL), or low (Met/Met, COMTLL). The objective of this study was to determine the response to entacapone in COMTHH and COMTLL PD patients.

Mycophenolic acid area under the curve correlates with disease activity in lupus patients treated with mycophenolate mofetil

OBJECTIVE Mycophenolic acid (MPA) is the active metabolite of mycophenolate mofetil (MMF), which is widely used to treat systemic lupus erythematosus (SLE). In transplantation, MPA area under the plasma concentration-time curve from 0 to 12 hours (MPA AUC(0-12)) is correlated with clinical outcome. We undertook the present study to assess possible relationships between SLE activity and MPA AUC(0-12). METHODS Using a Bayesian estimator, MPA AUC(0-12) was determined in 71 consecutive SLE patients (61 women and 10 men; mean +/- SD age 34 +/- 10 years) receiving a stable MMF dose. On the same day, SLE activity was assessed using the SLE Disease Activity Index (SLEDAI; active disease defined as a SLEDAI score > or = 6) and the British Isles Lupus Assessment Group (BILAG) index (active disease defined as BILAG A or B). RESULTS Two groups were studied: patients with active SLE (mean +/- SD SLEDAI score 11.6 +/- 4.4; n = 26) and patients with inactive SLE (mean +/- SD SLEDAI score 1.9 +/- 1.6; n = 45). MPA AUC(0-12) correlated weakly with the dose of MMF (r = 0.33, P = 0.005). Mean +/- SD MPA AUC(0-12) in the group with active SLE was significantly lower than that in the group with inactive SLE (26.8 +/- 13.6 microg.hour/ml versus 46.5 +/- 16.3 microg.hour/ml; P < 0.0001). MPA AUC(0-12) was negatively correlated with the SLEDAI (r = -0.64, P < 0.0001). In multivariate analysis, MPA AUC(0-12) was the sole parameter associated with SLE activity (odds ratio 0.89 [95% confidence interval 0.83-0.96], P = 0.002). The MPA AUC(0-12) threshold value of 35 microg.hour/ml was associated with the lowest risk of active SLE. CONCLUSION Our data show that SLE activity is strongly correlated with MPA AUC(0-12). An individualized dosing regimen of MMF, with a target AUC(0-12) of 35 microg.hour/ml, should be considered for SLE patients.

Pharmacokinetic Study of Mycophenolate Mofetil in Patients with Systemic Lupus Erythematosus and Design of Bayesian Estimator Using Limited Sampling Strategies

AbstractBackground: Monitoring of the area under the plasma concentration-time curve (AUC) of mycophenolic acid (MPA) has been developed for individual dose adjustment of mycophenolate mofetil (MMF) in renal allograft recipients. MMF is currently used as an off-label drug in the treatment of systemic lupus erythematosus (SLE), but factors of its exposition may be different in these patients and need to be determined for therapeutic drug monitoring (TDM) purposes. Objective: The aim of the study was to develop a maximum a posteriori probability (MAP) Bayesian estimator of MPA exposition in patients with SLE, with the objective of TDM based on a limited sample strategy. Methods: Twenty adult patients with SLE given a stable 1 g/day, 2 g/day or 3 g/day dose of MMF orally for at least 10 weeks were included in the study. MPA was measured by high-performance liquid chromatography (HPLC) coupled to a photodiode array detector (11 plasma measurements over 12 hours post-dose per patient). Free MPA concentrations were measured by HPLC with fluorescence detection. Two different one-compartment models with first-order elimination were tested to fit the data: one convoluted with a double γ distribution to describe secondary concentrations peaks, and one convoluted with a triple γ distribution to model a third, later peak. Results: A large interindividual variability in MPA concentration-time profiles was observed. The mean maximum plasma concentration, trough plasma concentration, time to reach the maximum plasma concentration and AUC from 0 to 12 hours (AUC12) were 13.6 ± 8.4 μg/mL, 1.4 ±1.2 μg/mL, 1.1 ± 1.2 hours and 32.2 ± 17.1 μg · h/mL, respectively. The mean free fraction of MPA was 1.7%. The one-compartment model with first-order elimination convoluted with a triple γ distribution best fitted the data. Accurate Bayesian estimates of the AUC12 were obtained using three blood samples collected at 40 minutes, 2 hours and 3 hours, with a coefficient of correlation (R) = 0.95 between the observed and predicted AUC12 and with a difference of <20% in 16 of the 20 patients. Conclusions: A specific pharmacokinetic model was built to accurately fit MPA blood concentration-time profiles after MMF oral dosing in SLE patients, which allowed development of an accurate Bayesian estimator of MPA exposure that should allow MMF monitoring based on the AUC12 in these patients. The predictive value of targeting one specific or different AUC values on patients’ outcome using this estimator in SLE will need to be evaluated.

Dramatic response of a BRAF V600E-mutated primary CNS histiocytic sarcoma to vemurafenib

Histiocytic sarcoma (HS) is classified within the malignant histiocytic disorders.1 Involvement of isolated CNS in HS, termed primary CNS-HS (PCNS-HS), is characterized by a proliferation of cells in the monocyte/macrophage lineage within the CNS.2–6 This case report documents the clinical, biological, pathologic, and radiologic spectrums of PCNS-HS.

Hydroxychloroquine-Induced Pigmentation in Patients With Systemic Lupus Erythematosus: A Case-Control Study

IMPORTANCE Hydroxychloroquine-induced pigmentation is not a rare adverse effect. Our data support the hypothesis that hydroxychloroquine-induced pigmentation is secondary to ecchymosis or bruising. OBJECTIVE To describe the clinical features and outcome of hydroxychloroquine (HCQ)-induced pigmentation in patients with systemic lupus erythematosus (SLE). DESIGN, SETTING, AND PARTICIPANTS In a case-control study conducted at a French referral center for SLE and antiphospholipid syndrome, 24 patients with SLE, with a diagnosis of HCQ-induced pigmentation, were compared with 517 SLE controls treated with HCQ. MAIN OUTCOMES AND MEASURES The primary outcome was the clinical features of HCQ-induced pigmentation. Skin biopsies were performed on 5 patients, both in healthy skin and in the pigmented lesions. The statistical associations of HCQ-induced pigmentation with several variables were calculated using univariate and multivariate analyses. RESULTS Among the 24 patients, skin pigmentation appeared after a median HCQ treatment duration of 6.1 years (range, 3 months-22 years). Twenty-two patients (92%) reported that the appearance of pigmented lesions was preceded by the occurrence of ecchymotic areas, which gave way to a localized blue-gray or brown pigmentation that persisted. Twenty-three patients (96%) had at least 1 condition predisposing them to easy bruising. Results from skin biopsies performed on 5 patients showed that the median concentration of iron was significantly higher in biopsy specimens of pigmented lesions compared with normal skin (4115 vs 413 nmol/g; P < .001). Using multivariate logistic regression, we found that HCQ-induced pigmentation was independently associated with previous treatment with oral anticoagulants and/or antiplatelet agents and with higher blood HCQ concentration. CONCLUSIONS AND RELEVANCE Hydroxychloroquine-induced pigmentation is not a rare adverse effect of HCQ. Our data support the hypothesis that HCQ-induced pigmentation is secondary to ecchymosis or bruising.

Dopa-decarboxylase gene polymorphisms affect the motor response to L-dopa in Parkinson's disease.

BACKGROUND In Parkinsons disease (PD), the response to L-dopa is highly variable and unpredictable. The major pathway for dopamine synthesis from L-dopa is decarboxylation by aromatic L-amino acid decarboxylase (AAAD, encoded by the DDC gene). OBJECTIVE To determine the motor response to L-dopa in PD patients as a function of the DDC gene promoter polymorphisms (rs921451 T > C polymorphism (DDC(T/C)) and rs3837091 AGAG del (DDC(AGAG/-))). METHODS Thirty-three Caucasian PD patients underwent an acute l-dopa challenge together with the peripheral AAAD inhibitor benserazide and were genotyped for rs921451 and rs3837091. The primary efficacy criterion was the motor response to L-dopa, as estimated by the area under the curve for the change in the Unified Parkinsons Disease Rating Scale part III (UPDRS) score relative to baseline (AUCΔUPDRS) in the 4 h following L-dopa administration. Secondary endpoints were pharmacokinetic parameters for plasma levels of L-dopa and dopamine. Investigators and patients were blinded to genotypes data throughout the study. RESULTS When adjusted for the L-dopa dose, the AUCΔUPDRS was significantly lower in DDC(CC/CT) patients (n = 14) than in DDC(TT) patients (n = 19) and significantly lower in DDC(-/- or AGAG/-) patients (n = 8) than in DDC(AGAG/AGAG) patients (n = 25). There were no significant intergroup differences in plasma pharmacokinetic parameters for L-dopa and dopamine. DISCUSSION The rs921451 and rs3837091 polymorphisms of the DDC gene promoter influence the motor response to L-dopa but do not significantly change peripheral pharmacokinetic parameters for L-dopa and dopamine. Our results suggest that DDC may be a genetic modifier of the l-dopa response in Parkinsons disease.

A new UPLC-MS/MS method for the determination of irinotecan and 7-ethyl-10-hydroxycamptothecin (SN-38) in mice: Application to plasma and brain pharmacokinetics

A sensitive and accurate liquid chromatography method with mass spectrometry detection using MRM in positive ion mode was developed and validated for the simultaneous quantification of irinotecan (CPT-11) and 7-ethyl-10-hydroxycamptothecin (SN-38) in mouse plasma and brain. Camptothecin (CPT) was used as internal standard. A single step protein precipitation was used for plasma sample preparation, and a liquid-liquid extraction was needed for brain sample preparation. The method was validated with respect to selectivity, extraction recovery, linearity, intra- and inter-day precision and accuracy, limit of quantification and stability. Limits of quantification were 5 ng/mL for CPT-11 and SN-38 in plasma samples and 1.25 ng/g in brain. Linear calibration curves were obtained over concentration ranges of 5-5000 ng/mL in plasma and 1.25-1250 ng/g in brain for CPT-11 and SN-38. The intra-day and inter-day variation (relative standard deviation, R.S.D.) found to be less than 15% for both substances in both media. Stability studies showed that plasma carboxylesterase had to be inactivated in order to prevent in vitro conversion of CPT-11 into SN-38. Zinc sulfate (1 M) was used to inactivate the enzyme before sample storage. Brain samples did not require enzyme inactivation. This method was successfully applied to perform brain and plasma pharmacokinetic studies of CPT-11 and SN-38 in mice after intraperitoneal administration.