Michel Mourad

Minimally invasive video-assisted thyroidectomy: multiinstitutional experience.

Minimally invasive video-assisted thyroidectomy (MIVAT) was described in 1998. In this study we collected the experience of four third-level referral centers that adopted this technique. A total of 336 patients (279 females, 57 males) were selected for MIVAT. Selection criteria were thyroid volume <15 ml, nodules not exceeding 3.5 cm of diameter, and an absence of thyroiditis, previous neck surgery, or previous irradiation. The procedure, totally gasless, is carried out through a 15 mm central incision above the sternal notch. Dissection is performed under endoscopic vision using conventional and endoscopic instruments. The mean operating time was 69.4 ± 30.6 minutes for lobectomy (range 20–150 minutes) and 87.4 ± 43.5 minutes for total thyroidectomy (range 30–220 minutes). The mean postoperative stay was 1.9 ± 0.8 days. Postoperative complications were 7 transient and 1 definitive recurrent nerve palsies and 11 cases of hypoparathyroidism (9 transient, 2 definitive). Conversion to open surgery was necessary in 15 patients (4.5%). This study confirms in a large number of cases the safety and feasibility of MIVAT, even in different surgical settings where similar results were achieved. The complication rate was not different from that of standard thyroidectomy. Although the operating time appears longer than with conventional procedures, the learning curve demonstrates a sharp decrease with increasing experience and the introduction of new technologies. The number of patients eligible for this approach remains low, thereby limiting its use, but it should be considered a valid option in selected surgical centers, offering some advantages to patients in terms of cosmetic results and postoperative distress.

Restoring the Association of the T Cell Receptor with CD8 Reverses Anergy in Human Tumor-Infiltrating Lymphocytes

For several days after antigenic stimulation, human cytolytic T lymphocyte (CTL) clones exhibit a decrease in their effector activity and in their binding to human leukocyte antigen (HLA)-peptide tetramers. We observed that, when in this state, CTLs lose the colocalization of the T cell receptor (TCR) and CD8. Effector function and TCR-CD8 colocalization were restored with galectin disaccharide ligands, suggesting that the binding of TCR to galectin plays a role in the distancing of TCR from CD8. These findings appear to be applicable in vivo, as TCR was observed to be distant from CD8 on human tumor-infiltrating lymphocytes, which were anergic. These lymphocytes recovered effector functions and TCR-CD8 colocalization after ex vivo treatment with galectin disaccharide ligands. The separation of TCR and CD8 molecules could be one major mechanism of anergy in tumors and other chronic stimulation conditions.

Persistence of a chimerical phenotype after hepatocyte differentiation of human bone marrow mesenchymal stem cells

Abstract.  Objectives: Recent studies have suggested the potential of mesenchymal stem cells (MSCs) to differentiate into a hepatocyte‐like lineage. Here, we evaluate the efficacy of hepatocyte differentiation of MSCs by studying acquisition of hepatocyte‐like features together with alteration of the native mesenchymal phenotype. Material and methods: In vitro, we have investigated protein and mRNA level expression of hepatocyte and mesenchymal markers of mesenchymal‐derived hepatocyte‐like cells (MDHLCs) and we have evaluated their functionality using metabolic assays. In vivo, we investigated co‐expression of hepatocyte (albumin, α‐foetoprotein, cytokeratin 18) and mesenchymal (fibronectin, vimentin) markers after transplantation of MSCs or MDHLCs into severe combined immune deficiency mice. Results: We observed that while in vitro these cells acquired some phenotypic and functional features of mature hepatocytes, they partially preserved their mesenchymal phenotype. After intrasplenic transplantation, engrafted MSCs with isolated expression of fibronectin and α‐foetoprotein were observed. When these cells were injected into the liver, they expressed all analysed markers, confirming the chimaeric co‐expression observed in vitro. Conversely, liver‐engrafted MDHLCs conserved their hepatocyte‐lineage markers but lost their chimaeric phenotype. Conclusions: Hepatocyte differentiation of MSCs predominantly allows the acquisition of phenotypic hallmarks and provides chimaeric cells that maintain expression of initial lineage markers. However, advanced maturation to the hepatocyte‐like phenotype could be obtained in vivo by conditioning MSCs prior to transplantation or by infusing cells into the liver micro‐environment.

Is plasma and urine neutrophil gelatinase-associated lipocalin (NGAL) determination in donors and recipients predictive of renal function after kidney transplantation?

OBJECTIVES Delayed graft function (DGF) is still a major issue in kidney transplantation. Plasma and urine neutrophil gelatinase-associated lipocalin (NGAL) were evaluated in a population of kidney donors and recipients to investigate their performance to predict early renal function. DESIGN AND METHODS Plasma (pNGAL) and urine (uNGAL) samples were obtained from donors before organ procurement, and from recipients before transplantation, and then 6, 24 and 48h after the procedure. Kidney transplantations were performed from both living donors (LDs, n=17) and deceased donors (DDs, n=80). Recovery of renal function was evaluated as the time to reach serum creatinine <2mg/l or glomerular filtration rate (GFR)>40mL/min. Logistic regression was used to assess the ability of different variables to predict the occurrence of DGF. RESULTS Plasma NGAL levels were significantly lower in LDs than in DDs. No episodes of DGF were recorded among LD kidney recipients, but DGF was observed in 25% of patients in the DD group. There was no correlation between donor pNGAL and uNGAL values and the occurrence of post-transplant DGF. Recipient pNGAL performed better than uNGAL in terms of predicting DGF occurrence. Donor pNGAL and uNGAL values did not influence the time needed to reach serum creatinine levels of <2mg/dl after transplantation. When time to reach eGFR of >40mL/min is considered, only donor uNGAL seems to be a predictor of graft function recovery. However, recipient pNGAL values obtained 24 and 48h after transplantation, but not uNGAL values, were found to be a significant predictor of graft function recovery. CONCLUSIONS Plasma NGAL level determination in recipients, but not in donors, proved to be a reliable predictor of DGF occurrence and renal function restoration, but too long for an interval to be able to compete with biomarkers currently used in clinical practice.

Donor age and ABCB1 1199G>A genetic polymorphism are independent factors affecting long-term renal function after kidney transplantation.

BACKGROUND In renal tubular cells, cytochrome P4503A enzyme and adenosine triphosphate-binding cassette transporter activities result in intracellular drug or metabolite exposure variability, depending on genetic polymorphisms. Our aim was to establish whether long-term renal function is affected by genetic polymorphisms in biotransformation enzymes and drug transporters of the donor after kidney transplantation. MATERIALS AND METHODS The study was conducted in a selected cohort of 97 kidney recipients. Genotyping of donors was performed on renal biopsy samples obtained before transplantation. Serum creatinine levels and Cockcroft-Gault estimated glomerular filtration rate were considered 1 y after transplantation and at the last follow-up. RESULTS Long-term function was significantly better in recipients of an organ from donors carrying the ABCB1 1199A mutated allele (median and range creatinine values were 1.1 mg/dL [0.8-1.5mg/dL] in case of at least one ABCB1 1199A allele versus 1.5 mg/dL [0.7-3.7 mg/dL] for homozygous carriers of wild-type allele, P < 0.01). ABCB1 1199G>A polymorphism and donor age had an independent impact on both serum creatinine and estimated glomerular filtration rate. Unlike donor age, the mutated ABCB1 1199A allele was found to have a protective effect on renal function. CONCLUSIONS Donor age and ABCB1 1199G>A polymorphism affect long-term renal function after transplantation. Analysis of genetic factors offers a promising approach to calcineurin inhibitor toxicity risk assessment.

Kidney donation after circulatory death in a country with a high number of brain dead donors: 10-year experience in Belgium

Worldwide shortage of standard brain dead donors (DBD) has revived the use of kidneys donated after circulatory death (DCD). We reviewed the Belgian DCD kidney transplant (KT) experience since its reintroduction in 2000. Risk factors for delayed graft function (DGF) were identified using multivariate analysis. Five‐year patient/graft survival was assessed using Kaplan–Meier curves. The evolution of the kidney donor type and the impact of DCDs on the total KT activity in Belgium were compared with the Netherlands. Between 2000 and 2009, 287 DCD KT were performed. Primary nonfunction occurred in 1% and DGF in 31%. Five‐year patient and death‐censored graft survival were 93% and 95%, respectively. In multivariate analysis, cold storage (versus machine perfusion), cold ischemic time, and histidine‐tryptophan‐ketoglutarate solution were independent risk factors for the development of DGF. Despite an increased number of DCD donations and transplantations, the total number of deceased KT did not increase significantly. This could suggest a shift from DBDs to DCDs. To increase KT activity, Belgium should further expand controlled DCD programs while simultaneously improve the identification of all potential DBDs and avoid their referral for donation as DCDs before brain death occurs. Furthermore, living donation remains underused.

Incidence of Posttransplantation Diabetes Mellitus in De Novo Kidney Transplant Recipients Receiving Prolonged-Release Tacrolimus-Based Immunosuppression With 2 Different Corticosteroid Minimization Strategies: ADVANCE, A Randomized Controlled Trial.

Background ADVANCE (NCT01304836) was a phase 4, multicenter, prospectively randomized, open-label, 24-week study comparing the incidence of posttransplantation diabetes mellitus (PTDM) with 2 prolonged-release tacrolimus corticosteroid minimization regimens. Methods All patients received prolonged-release tacrolimus, basiliximab, mycophenolate mofetil and 1 bolus of intraoperative corticosteroids (0-1000 mg) as per center policy. Patients in arm 1 received tapered corticosteroids, stopped after day 10, whereas patients in arm 2 received no steroids after the intraoperative bolus. The primary efficacy variable was the diagnosis of PTDM as per American Diabetes Association criteria (2010) at any point up to 24 weeks postkidney transplantation. Secondary efficacy variables included incidence of composite efficacy failure (graft loss, biopsy-proven acute rejection or severe graft dysfunction: estimated glomerular filtration rate (Modification of Diet in Renal Disease-4) <30 mL/min per 1.73 m2), acute rejection and graft and patient survival. Results The full-analysis set included 1081 patients (arm 1: n = 528, arm 2: n = 553). Baseline characteristics and mean tacrolimus trough levels were comparable between arms. Week 24 Kaplan–Meier estimates of PTDM were similar for arm 1 versus arm 2 (17.4% vs 16.6%; P = 0.579). Incidence of composite efficacy failure, graft and patient survival, and mean estimated glomerular filtration rate were also comparable between arms. Biopsy-proven acute rejection and acute rejection were significantly higher in arm 2 versus arm 1 (13.6% vs 8.7%, P = 0.006 and 25.9% vs 18.2%, P = 0.001, respectively). Tolerability profiles were comparable between arms. Conclusions A prolonged-release tacrolimus, basiliximab, and mycophenolate mofetil immunosuppressive regimen is efficacious, with a low incidence of PTDM and a manageable tolerability profile over 24 weeks of treatment. A lower incidence of biopsy-proven acute rejection was seen in patients receiving corticosteroids tapered over 10 days plus an intraoperative corticosteroid bolus versus those receiving an intraoperative bolus only.

Fourteen years of experience in uncontrolled organ donation after cardio-circulatory death

BACKGROUND Since 1999, a protocol for uncontrolled donation after cardio-circulatory death (DCD) has been carried out in our institution. We aimed at evaluating those 14 years of local experience. METHODS We reviewed the charts of uncontrolled donors from 1999 till 2013. Potential donors with a no-flow period less than 30 minutes were considered. Kidneys were perfused by the use of a double balloon triple lumen catheter after at least a 2-minute period of no touch. We analyzed grafts outcome and warm and cold ischemia times. RESULTS Thirty-nine procedures were initiated: 19 were aborted because of family refusal (n = 7), medical reasons (n = 7), or canulation failures (n = 5) and 20 harvesting procedures were completed. Transplantation was considered for 35 kidneys (cold storage [n = 5] and hypothermic preservation system [n = 30]). The causes of withdrawal from transplantation were mostly macroscopic lesions (poor perfusion, macroscopic parenchyma or vascular lesions, or infectious risk). We transplanted 22 kidneys locally and 3 were shipped to another Eurotransplant center. Mean donor age was 40 ± 13 years. Among the 20 donors, 13 came from the emergency unit and 7 from the intensive care unit. Mean no-flow time for out-hospital management was 8.7 ± 3.6 minutes. Mean time of cardiopulmonary resuscitation was 71 ± 46 minutes. Mean cold ischemia time was 19 ± 5 hours. Primary nonfunction and delayed graft function occurred in 1 and 12 cases (4.5% and 54%), respectively. Graft survival was 86% at 1 year. Causes of graft loss during the entire follow-up were graft rejection (n = 3), ischemically damaged kidney (n = 2), and recurrence of focal segmental glomerulosclerosis (n = 1). CONCLUSION In our experience, uncontrolled donors represent a valuable source of kidney grafts, with a prognosis of graft function and survival similar to the literature. To increase the number of available DCD organs, new techniques, such as the use of Normothermic ExtraCorporeal Membrane Oxygenation (NECMO), as well as improvement of recruitment of out of hospital potential donors have to be considered.

Tacrolimus Updated Guidelines through popPK Modeling: How to Benefit More from CYP3A Pre-emptive Genotyping Prior to Kidney Transplantation

Tacrolimus (Tac) is a profoundly effective immunosuppressant that reduces the risk of rejection after solid organ transplantation. However, its use is hampered by its narrow therapeutic window along with its highly variable pharmacological (pharmacokinetic [PK] and pharmacodynamic [PD]) profile. Part of this variability is explained by genetic polymorphisms affecting the metabolic pathway. The integration of CYP3A4 and CY3A5 genotype in tacrolimus population-based PK (PopPK) modeling approaches has been proven to accurately predict the dose requirement to reach the therapeutic window. The objective of the present study was to develop an accurate PopPK model in a cohort of 59 kidney transplant patients to deliver this information to clinicians in a clear and actionable manner. We conducted a non-parametric non-linear effects PopPK modeling analysis in Pmetrics®. Patients were genotyped for the CYP3A4∗22 and CYP3A5∗3 alleles and were classified into 3 different categories [poor-metabolizers (PM), Intermediate-metabolizers (IM) or extensive-metabolizers (EM)]. A one-compartment model with double gamma absorption route described very accurately the tacrolimus PK. In covariate analysis, only CYP3A genotype was retained in the final model (Δ-2LL = -73). Our model estimated that tacrolimus concentrations were 33% IC95%[20–26%], 41% IC95%[36–45%] lower in CYP3A IM and EM when compared to PM, respectively. Virtually, we proved that defining different starting doses for PM, IM and EM would be beneficial by ensuring better probability of target concentrations attainment allowing us to define new dosage recommendations according to patient CYP3A genetic profile.

Extended release tacrolimus and antiretroviral therapy in a renal transplant recipient: so extended!

HIV-infected patients are at risk of developing end-stage renal disease. In selected patients with controlled disease, kidney transplantation (KT) has been recognized during last years as a safe and effective treatment [1]. Highly active antiretroviral therapy (HAART) drugs can interfere with immunosuppressive agents, and this has to be taken into account when adjusting immunosuppression regimen. We report the case of an HIV1-infected patient who developed a severe interaction between extended-release (ER) tacrolimus and lopinavir boosted by ritonavir (lopinavir/r) shortly after KT. This resulted in sustained tacrolimus overdosage, surprisingly well tolerated by the renal graft. Careful therapeutic drug monitoring and pharmacokinetics follow-up, led to a drastic reduction of ER tacrolimus dosage administered on a once weekly basis. A 45-year-old man with end-stage renal disease secondary to cidofovir toxicity, given for CMV retinitis, underwent KT from a heart-beating deceased-donor after 5 years on haemodialysis. His past medical history included HIV-1 infection diagnosed 22 years earlier, without hepatitis B or C virus coinfection. CD4 cell count and viral load were 516/ll and below 50 copies/ll, respectively, 3 months before KT. Recovery of diuresis was immediate following KT and serum creatinine rapidly decreased from 9.97 mg/dl at admission to 1.06 mg/dl at day 7. Immunosuppressive regimen included ER tacrolimus 0.2 mg/kg o.d (Advagraf , Astellas Pharma Europe, Staines, UK), mycophenolate mofetil 500 mg b.i.d. (Cellcept , Roche, Basel, Switzerland) and prednisolone. At the time of KT, HAART included lopinavir/r 600/150 mg b.i.d., lamivudine 300 mg o.d., raltegravir 400 mg b.i.d. and nevirapine 200 mg b.i.d. Acetylsalicylic acid and prophylactic trimethoprime–sulfamethoxazole 800–160 mg three times a week were added in the early post-operative period. At day 3 post-KT, tacrolimus dosage, performed with Chemiluminescent Microparticle Immuno-Assay on the Architect analyser (Abbott Diagn., Chicago, IL, USA), had to be reduced because of trough levels >30 ng/ ml and completely withdrawn at day 7 (Fig. 1). On day 15, the patient developed fungal and herpetic oesophagitis treated with oral fluconazole 50 mg o.d. (for 10 days), aciclovir 800 mg b.i.d. and pantoprazole 40 mg o.d. Despite tacrolimus discontinuation, whole blood levels remained >30 ng/ml until day 30, with a value of 47.4 ng/ml obtained by dilution on day 24. On day 47, 40 days after drug discontinuation, trough level was