Catherine Amrein

Human Leukocyte Antigen-G Expression After Heart Transplantation Is Associated With a Reduced Incidence of Rejection

Background—Human leukocyte antigen (HLA)-G, a nonclassic major histocompatibility complex class I molecule expressed in the extravillous cytotrophoblast at the feto-maternal interface, is known to protect the fetus from maternal cellular immunity. In a preliminary study, we showed that HLA-G is expressed in the hearts of some patients after heart transplantation. Methods and Results—In the present study, a larger number of patients was investigated to confirm this finding and to look for possible correlations between HLA-G expression and the number and types of rejection. Expression of HLA-G in endomyocardial biopsy specimens was investigated by immunohistochemical analysis, and detection of the soluble HLA-G in the serum was performed by immunoprecipitation followed by Western blot analysis. HLA-G was detected in the biopsy specimens and serum of 9 of 51 patients (18%). The number of episodes of acute rejection was significantly lower in HLA-G-positive patients (1.2±1.1) as compared with HLA-G-negative patients (4.5±2.8) (P <0.001). No chronic rejection was observed in HLA-G-positive patients, whereas 15 HLA-G-negative patients had chronic rejection (P <0.032). A longitudinal study of these patients reveals that the status of HLA-G expression was maintained after 6 months both in serum and in biopsy specimens. During this period, HLA-G-positive patients did not have chronic rejection. Conclusions—There is a significant correlation between rejection and HLA-G expression in the heart after transplantation. HLA-G expression and its effect in reducing the incidence and severity of rejection seem to be stable throughout the evolution.

Implication of HLA-G molecule in heart-graft acceptance.

HLA-G found in five of 31 heart-transplant recipients was associated with a decrease of acute and chronic rejection episodes.

Cardiac stem cells in the real world

OBJECTIVE Cardiac stem cell transplantation as a potential means of regenerating infarcted myocardium is currently receiving a great deal of interest. However, data on these endogenous cardiac precursors are primarily derived from animal studies, and their clinical relevance still remains elusive. METHODS We prospectively screened 32 endomyocardial biopsies harvested from heart transplant recipients (off rejection episodes) and 18 right appendage biopsies collected during coronary artery bypass surgery, and processed the tissue specimens for the immunohistochemical detection of markers of stemness (c-kit, MDR-1, Isl-1), hematopoietic origin (CD45), mast cells (tryptase), endothelial cells (CD105), and cardiac lineage (Nkx2.5). Confocal microscopy was used for colocalization experiments. Three right appendage biopsies were also cultured for 2 to 3 weeks, at the completion of which c-kit-positive cells were sorted by flow cytometry. RESULTS In endomyocardial biopsies, a median number of 2.7 (1.8-4) c-kit-positive cells/mm(2) were found, and this number was even significantly smaller in right appendage biopsies (1 [0.5-1.8] c-kit-positive cell/mm(2), P = .01). All of these c-kit-positive cells co-stained for CD45 and were more specifically identified as mast cells by their positive staining for the specific tryptase marker. However, none of the c-kit-positive cells expressed the markers of stemness MDR-1 and Isl-1 or colocalized with CD105. Flow cytometry confirmed the small number of c-kit-positive cells in cultured right atrial appendages. CONCLUSION These data raise a cautionary note on the therapeutic exploitation of cardiac stem cells in patients with ischemic cardiomyopathy, who may be the elective candidates for regenerative therapy.

Combined lung and liver transplantation in patients with cystic fibrosis: A 4 1/2-year experience ☆ ☆☆ ★ ★★ ♢

Patients with cystic fibrosis who have end-stage respiratory failure and associated liver cirrhosis have been considered poor candidates for lung transplantation because of high morbidity and mortality resulting from hepatic insufficiency after the operation. Since April 1989, our policy has been to combine heart-lung or lung and liver transplantation in this group of patients. Between June 1990 and March 1995, among 25 patients accepted in the program for combined transplantation, nine died awaiting transplantation and 10 underwent one of the following procedures: heart-lung-liver transplantation (n = 5), en bloc double lung-liver transplantation (n = 1), sequential double lung-liver transplantation (n = 3), and bilateral lobar lung transplantation from a split left lung and reduced liver transplantation (n = 1). There were 5 male and 5 female patients. The ages of the recipients ranged from 10 to 24 years. Mean forced expiratory volume in 1 second was 29% and mean forced vital capacity was 35% of predicted values. All patients were infected with resistant Pseudomonas, three with Pseudomonas cepaceia, and two patients had Aspergillus species in addition. All patients had severe cirrhosis with portal hypertension. Four patients had a history of esophageal variceal bleeding and two had had previous portosystemic shunts. The operation was performed as a two-stage procedure, the intrathoracic operation being completed before the abdominal stage was begun. Cardiopulmonary bypass was used in all patients because of poor clinical condition. Immunosuppression consisted of azathioprine, cyclosporine, and prednisone, as for isolated lung transplantation. There were two perioperative deaths, one caused by primary liver failure and the second by early lung dysfunction. For the first 3 months after transplantation pulmonary infection was the most common cause of morbidity. Other complications included tracheal stenosis (n = 1), bronchial stenosis (n = 1), biliary stricture (n = 2), and severe ascites (n = 3). All were successfully treated. Obliterative bronchiolitis developed in three patients. This was stabilized with FK 506 in two patients; the other patient underwent retransplantation at 38 months but eventually died of bleeding. Actuarial survival was 70% at 1 year and remained unchanged at 3 years. Significant functional improvement was observed in all survivors. For patients who have chronic respiratory failure with advanced cirrhosis, lung transplantation combined with liver transplantation can be performed with a satisfactory outcome.

Very Late Heart Transplant Rejection Is Associated with Microvascular Injury, Complement Deposition and Progression to Cardiac Allograft Vasculopathy

In heart transplants, the significance of very late rejection (after 7 years post‐transplant, VLR) detected by routine endomyocardial biopsies (EMB) remains uncertain. Here, we assessed the prevalence, histopathological and immunological phenotype, and outcome of VLR in clinically stable patients. Between 1985 and 2009, 10 662 protocol EMB were performed at our institution in 398 consecutive heart transplants recipients. Among the 196 patients with >7‐year follow‐up, 20 (10.2%) presented subclinical ≥3A/2R‐ISHLT rejection. The VLR group was compared to a matched control group of patients without rejection. All biopsies were stained for C4d/C3d/CD68 with sera screened for the presence of donor‐specific antibodies (DSAs). In addition to cellular infiltrates with myocyte damage, 60% of VLR patients had evidence of intravascular macrophages. C4d and/or C3d‐capillary deposition was found in 55% VLR EMB. All cases of VLR associated with microcirculation injury had DSAs (mean DSAmax−MFI = 1751 ± 583). This entity was absent from the control group (p < 0.0001). Finally, after a similar follow‐up postreference EMB of 6.4 ± 1 years, the mean of CAV grade was 0.76 ± 0.18 in the control group compared to 2.06 ± 0.26 in the VLR group respectively, p = 0.001). There was no difference in patient survival between study and control groups. In conclusion, VLR is frequently associated with complement‐cascade activation, microvascular injury and DSA, suggesting an antibody‐mediated process. VLR is associated with a dramatic progression to severe CAV in long‐term follow‐up.

Voriconazole pharmacokinetic variability in cystic fibrosis lung transplant patients.

Background. Aspergillosis is a high‐risk complication in cystic fibrosis (CF) lung transplant patients. Azole antifungal drugs inhibit CYP3A4, resulting in significant metabolic drug–drug interactions. Voriconazole (VRZ) was marketed without therapeutic drug monitoring (TDM) recommendations, consistent with favorable pharmacokinetics, but regular determinations of plasma VRZ concentration were introduced in our center to manage interactions with calcineurin inhibitors and to document the achievement of therapeutic levels.

Pathologic classification of antibody-mediated rejection correlates with donor-specific antibodies and endothelial cell activation

BACKGROUND Humoral immune responses during heart transplantation may result in antibody-mediated rejection (AMR), which is now taken into account on endomyocardial biopsy (EMB) specimens and ranked according to the pathologic AMR (pAMR) grades of the International Society for Heart and Lung Transplantation classification. This classification might benefit from new immunohistological markers and validation by others biomarkers, namely donor-specific antibodies (DSA). METHODS From the 293 protocol EMBs performed in 113 patients in our institution during a 1-year period for this prospective study, 280 EMB specimens were available with both histology and immunohistochemistry. C4d and labeling of intravascular cells by cluster of differentiation (CD) 68 were performed on paraffin sections. Available sera (n = 150) concomitant of EMB specimens were tested for the presence of DSA. All of the pAMR+ EMB specimens, along with a set of randomized pAMR0 EMB specimens, were immunolabeled for mammalian target of rapamycin (mTOR) effectors, phosphorylated 70 S6-kinase (p70S6K) and phosphorylated S6 ribosomal protein (pS6RP). RESULTS AMR was diagnosed in 37 EMB specimens (13.2%): 1 pAMR1(I+), 27 pAMR1(H+), and 9 pAMR2. The proportion of DSA-positive EMB varied according to the pAMR grade, with pAMR0, pAMR1(H+), and pAMR2 EMB presenting 17.6%, 77.3%, and 100% of DSA-positivity, respectively. Among the 30 pAMR+ specimens with available DSA testing and the 30 pAMR0 randomized specimens, mTOR pathway immunohistochemistry showed endothelial cell positivity for p70S6K in 17 pAMR+ EMB specimens (56.7%) and in 1 pAMR0 EMB specimen (3.3%). pS6RP was detected in 8 pAMR+ EMB specimens (26.7%) and in 1 pAMR0 EMB specimen (3.3%). CONCLUSIONS p70S6K and pS6RP immunohistochemistry afford new markers of AMR on EMB specimens because their expression is correlated with microcirculation inflammation and DSA. The correlation of DSA with pAMR grade suggests that this grading system is valid.

Effect of systemic hypertension on renal function and left ventricular hypertrophy in heart transplant recipients

To evaluate the incidence, risk factors and effects of systemic hypertension on renal function and left ventricular hypertrophy after cardiac transplantation, 85 transplant recipients on triple drug, low dosage, immunosuppressive therapy were studied. After a mean follow-up period of 12.5 +/- 8.7 months, a high incidence of hypertension was observed in 57 (67%) of the patients, and 42 (71%) of the 57 had developed new hypertension. None of the pretransplant and posttransplant cardiovascular risk factors were significantly associated with posttransplant hypertension. Faster deterioration of renal function, as assessed by intraindividual variations of serum creatinine values, was demonstrated in hypertensive patients and appeared as an early indicator of cyclosporine nephrotoxicity in patients at risk for hypertension. Serial echocardiographic evaluations demonstrated an early increase in left ventricular mass and fractional shortening in both hypertensive and normotensive heart transplant recipients. Fractional shortening further diminished significantly in normotensive patients but remained elevated in hypertensive patients, demonstrating sustained enhanced contractility in this group. Further studies will help to determine the exact relation between cyclosporine dosages and hypertension and their respective roles in the development of renal insufficiency and left ventricular hypertrophy after cardiac transplantation.

Photosensibilisation au voriconazole : 7 cas

Resume Introduction Le voriconazole est un nouvel antifongique triazole de deuxieme generation derive du fluconazole. Presentant une puissance superieure sur les especes sensibles et un spectre plus large que le fluconazole, il constitue un traitement de choix des aspergilloses pulmonaires invasives et d’autres infections a Fusarium, Scedosporium/Pseudalleschezria et est indique dans les infections invasives a Candida resistantes au fluconazole. Nous rapportons 7 observations de photosensibilisation lors d’un traitement par voriconazole dans un contexte d’immunodepression. Observations Il s’agissait de 5 femmes et 2 hommes âges de 17 a 67 ans (moyenne = 38 ans), recevant un traitement immunosuppresseur dans le cadre d’une transplantation bipulmonaire pour mucoviscidose (5 cas), d’une transplantation renale sur nephroangiosclerose lupique (1 cas) et d’un syndrome de Sjogren (1 cas). Le developpement d’une aspergillose pulmonaire (6 cas) ou d’une infection a Scedosporium (1 cas) a motive la prescription de voriconazole. Une photosensibilisation est apparue dans un delai de 5 semaines a 14 mois apres le debut du traitement, faisant toujours suite a une exposition solaire parfois de faible intensite. Dans tous les cas, l’arret du medicament a entraine rapidement la disparition des signes cutanes. Discussion Les photosensibilisations au voriconazole sont signalees dans la litterature, bien que rarement rapportees. Les malades doivent etre informes de la possibilite de survenue de cet effet indesirable. La prescription de voriconazole en periode d’ensoleillement necessite une protection solaire.

Colonization and infection of pulmonary artery catheter in cardiac surgery patients: epidemiology and multivariate analysis of risk factors.

ObjectiveTo assess the incidence and etiology of colonization and infection of pulmonary artery catheters inserted in cardiac surgery patients. To determine the influence of some variables on the risk of developing pulmonary artery catheter colonization and infection. DesignProspective observational study of pulmonary artery catheters inserted into the internal jugular vein that were in place for >48 hrs over a 13-month period. Data collected included age, gender, nature of the cardiac surgery intervention, duration of extracorporeal circulation, date of insertion and removal, subsequent infection, and curative antimicrobial therapy. End points were pulmonary artery catheter colonization with ≥103 colonies on quantitative cultures and pulmonary artery catheter-related bacteremia. Risk factors for colonization were determined by multiple logistic regression. SettingA 17-bed cardiac surgery intensive care unit in a 480-bed teaching hospital in Paris. PatientsPatients undergoing cardiac surgery procedures between May 1, 1997, and May 31, 1998. InterventionsNone. Measurements and Main Results Of 164 pulmonary artery catheters inserted in 157 patients, 19 (11.6%) and 1 (0.6%) were associated with colonization (mean duration of catheterization, 7.5 ± 2.8 days) and bacteremia, respectively. These data represent an incidence of 17.7 and 0.93 episodes per 1000 catheterization-days, respectively. Pulmonary artery catheter colonization was caused by Gram-positive cocci in 48% (67% were coagulase-negative staphylococci), Gram-negative rods in 48%, and Candida albicans in 4%. From multivariate analysis, >4 days of catheterization was the single variable associated with a significantly increased risk of pulmonary artery catheter colonization (odds ratio, 9.81; 95% confidence interval, 1.24–77.5, p = .03). ConclusionsOur data show that the risk of pulmonary artery catheter-related colonization and bacteremia is quite low despite the use of a high-risk insertion site. In cardiac surgery patient populations, a trial evaluating the impact of a systematic pulmonary artery catheter removal after 4 days is warranted.