Infliximab desensitization in patients with inflammatory bowel diseases: a safe therapeutic alternative.

BACKGROUND: Hypersensitivity reactions (HSR) to the administration of infliximab (IFX) in Inflammatory Bowel Diseases (IBD) patients are not rare and usually lead to drug discontinuation. We report data on safety and effectiveness of desensitization to IFX in patients with previous HSR. METHODS: We conducted a retrospective monocentric observational study. Patients for whom a desensitization protocol to IFX was realized after a previous HSR were included. Anti-drug antibodies (ADA) and IFX trough levels at both inclusion and six months after desensitization were collected. Clinical outcomes, including recurrence of HSR were evaluated. RESULTS: From 2005 to 2020, 27 patients (Crohn's Disease: 26 (96%) were included). Desensitization after HSR was performed after a median time of 10.4 months (2.9-33.1). Nineteen (70%) patients received immunosuppressants at time of desensitization. Eight (30%) patients presented HSR at first (n = 2), second (n = 4) or third (n = 2) IFX perfusion after desensitization. None led to intensive care unit transfer or death. Thirteen (48%) had clinical response at 6 months and 8 (29%) were still under IFX treatment two years after desensitization. IFX trough levels and ADA were available for 14 patients at time of desensitization. Most patients (12 out of 14) had ADA at a high level. At 6 months, among the 7 patients with long term response to IFX, 4 presented a decrease of ADA titers and 2 had a significant trough level of IFX. CONCLUSION: IFX desensitization in patients with IBD is a safe therapeutic alternative and represents a potential option for patients refractory to multiple biologics.What is already known? Hypersensitivity reactions to the administration of infliximab is frequent. Occurrence of hypersensitivity reaction, either immediate or delayed, usually leads to permanent drug discontinuation.What is new here? Infliximab desensitization is well tolerated with no hypersensitivity reaction recurrence in 70% of patients. Clinical success at 6 months was of 48% and around a third of patients remained under infliximab therapy two years after desensitization. Antidrug antibodies decreased and infliximab trough levels increased in these patients showing the impact of desensitization on immunogenicity.How can this study help patient care? Infliximab desensitization represents a potential option for patients refractory to multiple biologics who presented hypersensitivity reaction to the drug.

Simultaneous quantification and structural characterization of monoclonal antibodies after administration using capillary zone electrophoresis-tandem mass spectrometry.

Monoclonal antibodies (mAbs) are demonstrating major success in various therapeutic areas such as oncology and the treatment of immune disorders. Over the past two decades, novel analytical methodologies allowed to address the challenges of mAbs characterization in the context of their production. However, after administration only their quantification is performed and insights regarding their structural evolution remain limited. For instance, clinical practice has recently highlighted significant inter-patient differences in mAb clearance and unexpected clinical responses, without providing alternative interpretations. Here, we report the development of a novel analytical strategy based on capillary zone electrophoresis coupled to tandem mass spectrometry (CE-MS/MS) for the simultaneous absolute quantification and structural characterization of infliximab (IFX) in human serum. CE-MS/MS quantification was validated over the range 0.4-25 µg·mL-1 corresponding to the IFX therapeutic window and achieved a LOQ of 0.22 µg·mL-1 (1.5 nM) while demonstrating outstanding specificity compared to the ELISA assay. CE-MS/MS allowed structural characterization and estimation of the relative abundance of the six major N-glycosylations expressed by IFX. In addition, the results allowed characterization and determination of the level of modification of post-translational modifications (PTMs) hotspots including deamidation of 4 asparagine and isomerization of 2 aspartate. Concerning N-glycosylation and PTMs, a new normalization strategy was developed to measure the variation of modification levels that occur strictly during the residence time of IFX in the patient's system, overcoming artefactual modifications induced by sample treatment and/or storage. The CE-MS/MS methodology was applied to the analysis of samples from patients with Crohn's disease. The data identified a gradual deamidation of a particular asparagine residue located in the complementary determining region that correlated with IFX residence time, while the evolution of IFX concentration showed significant variability among patients.

Structural identification and absolute quantification of monoclonal antibodies in suspected counterfeits using capillary electrophoresis and liquid chromatography-tandem mass spectrometry.

Monoclonal antibodies (mAbs) represent a major category of biopharmaceutical products which due to their success as therapeutics have recently experienced the emergence of mAbs originating from different types of trafficking. We report the development of an analytical strategy which enables the structural identification of mAbs in addition to comprehensive characterization and quantification in samples in potentially counterfeit samples. The strategy is based on the concomitant use of capillary zone electrophoresis analysis (CZE-UV), size exclusion chromatography coupled to multi-angle light scattering (SEC-MALS) and liquid chromatography hyphenated to tandem mass spectrometry (LC-MS/MS). This analytical strategy was applied to the investigation of different samples having unknown origins seized by the authorities, and potentially incorporating an IgG 4 or an IgG 1. The results achieved from the different techniques demonstrated to provide orthogonal and complementary information regarding the nature and the structure of the different mAbs. Therefore, they allowed to conclude unequivocally on the identification of the mAbs in the potentially counterfeit samples. Finally, a LC-MS/MS quantification method was developed which specificity was to incorporate a different mAbs labeled with stable isotopes as internal standard. The LC-MS/MS quantification method was validated and thus demonstrated the possibility to use common peptides with the considered IgG in order to achieve limit of quantification as low as 41.4 nM. The quantification method was used to estimate the concentration in the investigated samples using a single type of internal standard and experimental conditions, even in the case of mAbs with no stable isotope labeled homologues available.

Study of a new device for washing and concentrating cryopreserved hematopoietic stem cells and mononuclear cells: a single center experience.

BACKGROUND AIMS: Cryopreserved cellular products, as parts of hematopoietic progenitor cell (HPC) transplants, mononuclear cell reinjections for donor lymphocyte infusion or extracorporeal photopheresis, can be washed before being reinjected into the patient or infused directly, depending on local practices. The aim of washing is to reduce the incidence and severity of adverse reactions (ARs) due to the dimethyl sulfoxide (DMSO) used as a cryoprotective agent and other factors, such as dead cell debris. At the authors' cell therapy laboratory (CTL) in Poitiers, France, as in 76% of Etablissement Français du Sang (EFS) CTLs, all cryopreserved products undergo thawing in a water bath followed by washing with the COBE 2991. As this device will soon cease to be available, an alternative process needs to be assessed. METHODS: The authors compared two closed systems: the authors' semi-automatic system using the traditional centrifugation method (COBE 2991) and an automated device using spinning membrane filtration (Lovo). A total of 72 HPC bags available for research were used. The authors first performed a paired comparison, processing one or two HPC bags washed by each device. A second study was carried out to compare two different washing solutions generally used by EFS CTLs along with variable storage conditions. Finally, the authors studied the efficiency of the Lovo with three or four thawed bags. The main parameters studied were viable CD34+ cell recovery and viability, CD3+ cell recovery, stability up to 6 h after washing, DMSO elimination and center feasibility. RESULTS: The Lovo device showed better CD34+ cell recovery compared with the COBE 2991 while maintaining CD34+ viability and stability over 6 h. Moreover, Lovo efficiency seemed to be independent of the number of thawed bags processed and washing solution used in the authors' study. CD3+ cell recovery met the authors' internal specifications (cell recovery >50%), with similar results seen when processing with either the COBE 2991 or Lovo. Additionally, on average, 97% of DMSO was removed after washing with Lovo, minimizing the risk of ARs. The storage conditions post-processing indicated preferred storage conditions of 7 ± 3°C. Finally, if processing time seemed shorter using COBE 2991 for one bag washed, the Lovo device required only one staff member regardless of the number of HPC bags processed. CONCLUSIONS: The Lovo device seems to provide an opportunity to standardize HPC processing, ensuring patient safety, with, on average, 97% of DMSO removed, while improving recovery of cells of interest and maintaining viability over time in case of delayed transplant. The Lovo device consequently seems to be a serious alternative to the COBE 2991.

Europium labeled lactosylated albumin as a model workflow for the development of biotherapeutics.

Lactosylated albumin is currently used as a radiopharmaceutical agent to image the liver asialoglycoprotein receptors and quantify hepatic liver function in various diseases. A lactosylated protein (LACTAL) conjugate showed excellent liver uptake compared to non-lactosylated protein and a high signal to noise ratio, based on the biodistribution in mice using 99mTc-scintigraphy. However, in the laboratory, it is useful to have a method that can be used in daily practice to quantify cellular targeting or biodistribution. We propose a methodology from synthesis validation to pre-clinical demonstration and introduce a new practical detector (LACTAL.Eu) of the LACTAL molecule in biological media. We confirmed the purity and colloidal stability of the sample through physical analytical techniques, then showed the absence of in vitro toxicity of the agent and demonstrated in vitro targeting. Taking advantage of the fluorescence decay of the lanthanide, we performed measurements directly on the cell media without any further treatment. Finally, biodistribution in mice was confirmed by ex vivo measurements.

Revealing the potential of capillary electrophoresis/mass spectrometry: the tipping point.

The hyphenation of capillary electrophoresis and mass spectrometry (CE/MS) remains a minor technique compared with liquid chromatography/mass spectrometry (LC/MS), which represents nowadays the standard instrumentation, regardless of its introduction thirty years ago. However, from a theoretical point of view, CE coupling should be quite favorable especially with electrospray ionization mass spectrometry (ESI-MS). At the time, the sensitivity provided by CE/MS was often limited, due to hyphenation requirements, which at some point appeared to disqualify CE/MS from benefiting from the performance gain driving the evolution of MS instruments. However, this context has been significantly modified in a matter of a few years. The development of innovative CE/MS interfacing systems has enabled an important improvement regarding sensitivity and reinforced robustness in order to provide an instrumentation accessible to the largest scientific community. Because of the unique selectivity delivered by the electrophoretic separation, CE/MS has proved to be particularly relevant for the analysis of biological molecules. The conjunction of these aspects is motivating the interest in CE/MS analysis and shows that CE/MS is mature enough to enrich the toolbox of analytical techniques for the analysis of complex biological samples. Here we discuss the characteristics of the major types of high-sensitivity CE/ESI-MS instrumentation and emphasize the late evolution and future positioning of CE/MS analysis for the characterization of biological molecules like peptides and proteins, through some pertinent applications.

Sevoflurane for procedural sedation in critically ill patients: A pharmacokinetic comparative study between burn and non-burn patients.

BACKGROUND: Sevoflurane has anti-inflammatory proprieties and short lasting effects making it of interest for procedural sedation in critically ill patients. We evaluated the pharmacokinetics of sevoflurane and metabolites in severely ill burn patients and controls. The secondary objective was to assess potential kidney injury. METHODS: Prospective interventional study in a burn and a surgical intensive care unit; 24 mechanically ventilated critically ill patients (12 burns, 12 controls) were included. The sevoflurane was administered with an expired fraction target of 2% during short-term procedural sedation. Plasma concentrations of sevoflurane, hexafluoroisopropanolol (HFIP) and free fluoride ions were recorded at different times. Kinetic Pro (Wgroupe, France) was used for pharmacokinetic analysis. Kidney injury was assessed with neutrophil gelatinase-associated lipocalin (NGAL). RESULTS: The mean total burn surface area was 36±11%. The average plasma concentration of sevoflurane was 70.4±37.5mg·L-1 in burns and 57.2±28.1mg·L-1 in controls at the end of the procedure (P=0.58). The volume of distribution was higher (46.8±7.2 vs 22.2±2.50L, P<0.001), and the drug half-life longer in burns (1.19±0.28h vs 0.65±0.04h, P<0.0001). Free metabolite HFIP was higher in burns. Plasma fluoride was not different between burns and controls. NGAL did not rise after procedures. CONCLUSION: We observed an increased volume of distribution, slower elimination rate, and altered metabolism of sevoflurane in burn patients compared to controls. Repeated use for procedural sedation in burn patients needs further evaluation. No renal toxicity was detected. TRIAL REGISTRY NUMBER: ClinicalTrials.gov Identifier NCT02048683.

Pre-clinical assessment of the Lovo device for dimethyl sulfoxide removal and cell concentration in thawed hematopoietic progenitor cell grafts.

BACKGROUND: Cryopreserved hematopoietic progenitor cell (HPC) grafts are widely infused to patients with malignant and nonmalignant conditions. Despite reduction of immediate side effects linked to dimethyl sulfoxide (DMSO), cell debris-containing grafts and comparable hematopoietic engraftment between washed and unwashed cryopreserved products, bedside infusion of thawed HPC grafts is still preferred. Introduction of automated devices is important for standardization and consistency of graft manipulation. Additionally, these techniques are likely to be useful for the delivery of innovative cell-based medicinal products that are currently under development. METHODS: In this study, we evaluated three consecutive versions of the Lovo device (Fresenius Kabi) for automated washing of thawed HPC products. A total of 42 HPC products intended for destruction were used. Measured outcomes included viable CD34+ cell recovery, viability, total processing time and post-washing stability. RESULTS: Preliminary data using the prototype Lovo 0.0 to process a single HPC unit showed better recovery and viability of CD34+ cells using a two-cycle than a three-cycle wash, with >95% DMSO elimination. The Lovo 1.0 performed equally well. When simultaneously processing two HPC units, the upgraded Lovo 2.0 device demonstrated comparable CD34+ recovery, DMSO elimination efficiencies and time-saving capacity. Furthermore, washed cell products were stable for 4 hours at room temperature. DISCUSSION: Lovo device satisfies clinically relevant issues: ability to efficiently wash two HPC units simultaneously and compatibility with transport to nearby transplantation centers.

Cationic microbubbles and antibiotic-free miniplasmid for sustained ultrasound-mediated transgene expression in liver.

Despite the increasing number of clinical trials in gene therapy, no ideal methods still allow non-viral gene transfer in deep tissues such as the liver. We were interested in ultrasound (US)-mediated gene delivery to provide long term liver expression. For this purpose, new positively charged microbubbles were designed and complexed with pFAR4, a highly efficient small length miniplasmid DNA devoid of antibiotic resistance sequence. Sonoporation parameters, such as insonation time, acoustic pressure and duration of plasmid injection were controlled under ultrasound imaging guidance. The optimization of these various parameters was performed by bioluminescence optical imaging of luciferase reporter gene expression in the liver. Mice were injected with 50µg pFAR4-LUC either alone, or complexed with positively charged microbubbles, or co-injected with neutral MicroMarker™ microbubbles, followed by low ultrasound energy application to the liver. Injection of the pFAR4 encoding luciferase alone led to a transient transgene expression that lasted only for two days. The significant luciferase signal obtained with neutral microbubbles decreased over 2days and reached a plateau with a level around 1 log above the signal obtained with pFAR4 alone. With the newly designed positively charged microbubbles, we obtained a much stronger bioluminescence signal which increased over 2days. The 12-fold difference (p<0.05) between MicroMarker™ and our positively charged microbubbles was maintained over a period of 6months. Noteworthy, the positively charged microbubbles led to an improvement of 180-fold (p<0.001) as regard to free pDNA using unfocused ultrasound performed at clinically tolerated ultrasound amplitude. Transient liver damage was observed when using the cationic microbubble-pFAR4 complexes and the optimized sonoporation parameters. Immunohistochemistry analyses were performed to determine the nature of cells transfected. The pFAR4 miniplasmid complexed with cationic microbubbles allowed to transfect mostly hepatocytes compared to its co-injection with MicroMarker™ which transfected more preferentially endothelial cells.

Postoperative Complications after Ileocecal Resection in Crohn's Disease: A Prospective Study From the REMIND Group.

OBJECTIVES: We sought to determine the frequency of and risk factors for early (30-day) postoperative complications after ileocecal resection in a well-characterized, prospective cohort of Crohn's disease patients. METHODS: The REMIND group performed a nationwide study in 9 French university medical centers. Clinical-, biological-, surgical-, and treatment-related data on the 3 months before surgery were collected prospectively. Patients operated on between 1 September 2010 and 30 August 2014 were included. RESULTS: A total of 209 patients were included. The indication for ileocecal resection was stricturing disease in 109 (52%) cases, penetrating complications in 88 (42%), and medication-refractory inflammatory disease in 12 (6%). A two-stage procedure was performed in 33 (16%) patients. There were no postoperative deaths. Forty-three (21%) patients (23% of the patients with a one-stage procedure vs. 9% of those with a two-stage procedure, P=0.28) experienced a total of 54 early postoperative complications after a median time interval of 5 days (interquartile range, 4-12): intra-abdominal septic complications (n=38), extra-intestinal infections (n=10), and hemorrhage (n=6). Eighteen complications (33%) were severe (Dindo-Clavien III-IV). Reoperation was necessary in 14 (7%) patients, and secondary stomy was performed in 8 (4.5%). In a multivariate analysis, corticosteroid treatment in the 4 weeks before surgery was significantly associated with an elevated postoperative complication rate (odds ratio (95% confidence interval)=2.69 (1.15-6.29); P=0.022). Neither preoperative exposure to anti-tumor necrosis factor (TNF) agents (n=93, 44%) nor trough serum anti-TNF levels were significant risk factors for postoperative complications. CONCLUSIONS: In this large, nationwide, prospective cohort, postoperative complications were observed after 21% of the ileocecal resections. Corticosteroid treatment in the 4 weeks before surgery was significantly associated with an elevated postoperative complication rate. In contrast, preoperative anti-TNF therapy (regardless of the serum level or the time interval between last administration and surgery) was not associated with an elevated risk of postoperative complications.

In Vitro Analysis of the Interaction between Atovaquone and Proguanil against Liver Stage Malaria Parasites.

The interaction between atovaquone and proguanil has never been studied against liver stage malaria, which is the main target of this drug combination when used for chemoprevention. Using human hepatocytes lacking cytochrome P450 activity, and thus avoiding proguanil metabolizing into potent cycloguanil, we show in vitro that the atovaquone-proguanil combination synergistically inhibits the growth of rodent Plasmodium yoelii parasites. These results provide a pharmacological basis for the high efficacy of atovaquone-proguanil used as malaria chemoprevention.

Methadone dose in heroin-dependent patients: role of clinical factors, comedications, genetic polymorphisms and enzyme activity.

AIMS: Methadone is characterized by wide intersubject variability regarding the dose needed to obtain full therapeutic response. We assessed the influence of sociodemographic, ethnic, clinical, metabolic and genotypic variables on methadone maintenance dose requirement in opioid-dependent responder patients. METHODS: Eighty-one stable patients (60 men and 21 women, 43.7 ± 8.1 years old, 63.1 ± 50.9 mg day(-1) methadone), divided into quartiles with respect to the median daily dose, were enrolled and underwent clinical examination, treatment history and determination of liver/intestinal cytochrome P450 (CYP) 3A4 activity measured by the midazolam test, R,S-methadone trough concentration and clinically significant polymorphisms of the OPRM1, DRD2, COMT, ABCB1, CYP2B6, CYP3A5, CYP2C19 and CYP2D6 genes. RESULTS: Methadone maintenance dose was correlated to the highest dose ever used (r(2) = 0.57, P < 0.0001). Fractioned methadone intake (odds ratio 4.87, 95% confidence interval 1.27-18.6, P = 0.02), bodyweight (odds ratio 1.57, 95% confidence interval 1.01-2.44, P = 0.04), history of cocaine dependence (80 vs. 44 mg day(-1) in never-addict patients, P = 0.005) and ethnicity (Asian > Caucasian > African, P = 0.04) were independently associated with high-dose methadone in multiple regression analysis. A modest correlation was observed between liver/intestinal CYP3A4 activity and methadone dose at steady state (Spearman rank correlation coefficient [rs ] = 0.21, P = 0.06) but not with highest dose ever used (rs = 0.15, P = 0.18) or dose-normalized R,S-methadone trough concentrations (rs = -0.05, P = 0.64). Concomitant CYP3A4 inhibitors only affected the relationship between methadone dose and R,S-methadone trough concentration. None of the genetic polymorphisms explored was predictive of the methadone maintenance dose. CONCLUSIONS: Methadone maintenance dose was predicted by sociodemographic and clinical variables rather than genetic polymorphisms or liver/intestinal CYP3A4 activity in stable patients.

Lectin affinity electrophoresis of serum alkaline phosphatase in metastasized breast cancer.

The use of serum alkaline phosphatase (ALP) isoenzymes as markers of breast cancer metastases and treatment efficacy has received little attention. Twenty-six breast cancer women (56+/-13 years, all post-menopausal) were prospectively evaluated during their first and third course of chemotherapy (4-week interval). Serum samples were analyzed for ALP isoenzymes (bone, liver, and intestine) using a lectin affinity electrophoresis kit (Hydragel 15 ISO-PAL, Sebia) adapted on a semi-automated Hydrasys system (Sebia). Results were compared with imaging techniques for the presence of metastases; bone ALP isoenzyme (B-ALP) results were compared with C-Terminal degradation products of type I collagen (S-CTX) (CrossLaps, IDS Nordic). Serum B-ALP, but not S-CTX, confirmed the presence of bone metastases (BM) (n=15) with 67/100% sensitivity/specificity (using a 69 UI/L ROC cut-off); ROC AUC was 0.806 (P=0.0004) (NS for S-CTX). Chemotherapy reduced serum B-ALP by 24% over 4 weeks (P=0.0012); there was no change for S-CTX. There was no specific clinical pattern for other ALP isoenzymes (liver and intestine). In conclusion, serum B-ALP, but not S-CTX, could help confirm the presence of BM in breast cancer patients.

Plasma exchanges overcome persistent iodine overload to enable 131I ablation of differentiated thyroid carcinoma.

BACKGROUND: Amiodarone has a high iodine content that can induce persistent iodine excess and may prevent radioiodine (RI) treatment. PATIENT: A 55-year-old obese man had taken amiodarone (200 mg/d) for 3 years and stopped 2 years earlier. He underwent total thyroidectomy for papillary cancer with extrathyroidal extension and a metastatic central lymph node, requiring RI treatment. But iodine overload, with no other documented iodinated drug intake, was found (urinary iodine excretion = 472 microg/24 h; normal < 150 microg/24 h), and persisted 3 months later. Plasma exchanges (PE) were prescribed. INTERVENTIONS AND RESULTS: Eight PE over 4 weeks were needed to eliminate 39,295 nmol of iodine. Urinary iodine excretion and serum iodine concentrations, before PE and after eight sessions were, respectively: 230 and 84 nmol/mmol of creatinine, and 811 and 71 nmol/L, enabling RI treatment (4 GBq (131)I). Post-therapy whole-body scan revealed cervical uptake (0.48% of the total administered dose) corresponding to usual thyroid remnants. Ablation efficacy was confirmed 6 and 24 months later by cervical ultrasonography combined with an undetectable serum thyroglobulin level after recombinant human thyrotropin stimulation. CONCLUSIONS: When spontaneous iodine elimination is too slow to allow RI treatment of high-risk thyroid carcinoma within a reasonable time after thyroidectomy, PE are reliable and effective to overcome iodine overload.