The DESCARTES-Nantes survey of kidney transplant recipients displaying clinical operational tolerance identifies 35 new tolerant patients and 34 almost tolerant patients.

BACKGROUND: Kidney recipients maintaining a prolonged allograft survival in the absence of immunosuppressive drugs and without evidence of rejection are supposed to be exceptional. The ERA-EDTA-DESCARTES working group together with Nantes University launched a European-wide survey to identify new patients, describe them and estimate their frequency for the first time. METHODS: Seventeen coordinators distributed a questionnaire in 256 transplant centres and 28 countries in order to report as many 'operationally tolerant' patients (TOL; defined as having a serum creatinine <1.7 mg/dL and proteinuria <1 g/day or g/g creatinine despite at least 1 year without any immunosuppressive drug) and 'almost tolerant' patients (minimally immunosuppressed patients (MIS) receiving low-dose steroids) as possible. We reported their number and the total number of kidney transplants performed at each centre to calculate their frequency. RESULTS: One hundred and forty-seven questionnaires were returned and we identified 66 TOL (61 with complete data) and 34 MIS patients. Of the 61 TOL patients, 26 were previously described by the Nantes group and 35 new patients are presented here. Most of them were noncompliant patients. At data collection, 31/35 patients were alive and 22/31 still operationally tolerant. For the remaining 9/31, 2 were restarted on immunosuppressive drugs and 7 had rising creatinine of whom 3 resumed dialysis. Considering all patients, 10-year death-censored graft survival post-immunosuppression weaning reached 85% in TOL patients and 100% in MIS patients. With 218 913 kidney recipients surveyed, cumulative incidences of operational tolerance and almost tolerance were estimated at 3 and 1.5 per 10 000 kidney recipients, respectively. CONCLUSIONS: In kidney transplantation, operational tolerance and almost tolerance are infrequent findings associated with excellent long-term death-censored graft survival.

Early and irreversible recurrence MPO-ANCA-positive glomerulonephritis after renal transplantation.

Kidney transplantation (KTx) is the treatment of choice for eligible patients suffering from anti-neutrophil cytoplasmic antibody(ANCA)-associated vasculitis (AAV) who are in clinical remission, regardless of ANCA status. With current immunosuppressive protocols, the recurrence rate of this primary disease in the kidney graft is low and is generally observed after the 1st year of transplantation, with a favorable outcome following conventional treatment. We report here two unusual observations of early (diagnosed within 2 weeks) and aggressive (graft failure despite therapy) recurrences in the kidney graft. These observations suggest that systematic induction by depleting antibodies and antibiotic prophylaxis may help prevent this rare but severe condition. In addition, we monitored these patients for the anti- lysosomal membrane protein-2 antibody (LAMP2ab) titers, but we found that LAMP2ab titers were not a surrogate marker of early recurrence if the LAMP2ab concentration was higher in AVV recipients before KTx. Finally, we must keep in mind that rare cases of early and aggressive recurrence ANCA-associated vasculitis on kidney graft are a challenge for early diagnosis and treatment.

Elevated soluble Flt1 inhibits endothelial repair in PR3-ANCA-associated vasculitis.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis exhibits endothelial damage, but the capacity for vessel repair in this disorder is not well understood. Here, we observed a marked increase in serum levels of soluble Flt1 (sFlt1), a potent inhibitor of vascular endothelial growth factor, in patients with active ANCA-associated vasculitis compared with patients during remission and other controls. Serum levels of sFlt1 correlated with C5a, an anaphylatoxin released after complement activation. Serum from patients with acute ANCA-associated vasculitis disrupted blood flow in the chicken chorioallantoic membrane assay, suggesting an antiangiogenic effect. Preincubation with excess human vascular endothelial growth factor prevented this effect. Anti-proteinase-3 (PR3) mAb and serum containing PR3-ANCA from patients with active vasculitis both induced a significant and sustained release of sFlt1 from monocytes, whereas anti-myeloperoxidase (MPO) mAb or polyclonal antibodies did not. However, the serum containing polyclonal PR3-ANCA did not induce release of sFlt1 from cultured human umbilical vein endothelial cells. In summary, these data suggest that anti-PR3 antibodies, and to a much lesser extent anti-MPO antibodies, increase sFlt1 during acute ANCA-associated vasculitis, leading to an antiangiogenic state that hinders endothelial repair.

Kidney and liver transplantation in patients with autosomal recessive polycystic kidney disease: a multicentric study.

BACKGROUND AND OBJECTIVES: In contrast to the improvement in our understanding of the pathogenesis and presentation of autosomal recessive polycystic kidney disease (ARPKD), data regarding the issue of kidney and liver transplantation in patients with ARPKD remain particularly scarce. Here, we report the results and outcome of renal and/or liver transplantation in a series of patients with ARPKD. METHODS: Fourteen ARPKD patients (age: 3-25 years) who underwent renal transplantation with or without liver transplantation were retrospectively identified in five French nephrology departments. The patients' medical charts were reviewed and relevant data were collected. RESULTS: The clinical and radiological presentation of the 14 patients was highly variable illustrating the heterogeneity of ARPKD. Six patients underwent kidney and/or liver transplantation in adulthood. First renal graft survival was 92, 78 and 14% at 1, 5 and 10 years after renal transplantation, respectively. Mortality rate was relatively high (3/14; 21%) in these young patients and was directly related to infectious complications (recurrent angiocholitis) of severe Caroli's disease (dilatation of intra- and/or extra-hepatic bile ducts), a typical feature of ARPKD. CONCLUSIONS: Our data suggest that ARPKD patients evaluated for renal transplantation should be carefully screened for severe Caroli's disease. Even though the limited number of patients included in our study precludes any definite recommendation, pre-emptive liver transplantation may be a therapeutic option in ARPKD patients with severe Caroli's disease evaluated for renal transplantation.

Identification of a gene expression profile associated with operational tolerance among a selected group of stable kidney transplant patients.

Despite their utility, immunosuppressive treatments have numerous side effects, including infectious complications, malignancies and metabolic disorders, all of which contribute to long-term graft loss. In addition to the development of new pharmaceutical products with reduced toxicity and more comfortable modes of administration, tailoring immunosuppression according to the immune status of each patient would represent a significant breakthrough. Gene expression profiling has been shown to be a clinically relevant monitoring tool. In this paper, we have assessed the overall long-term kidney transplant outcome and attempted to identify operationally tolerant-like patients among recipients with stable clinical status at least 5 years post-transplantation. We thus measured a combination of noninvasive blood biomarkers of operational tolerance in a cohort of 144 stable patients and showed that only 3.5% exhibited a gene expression profile of operational tolerance, suggesting that such a profile can be detected under immunosuppressive therapy but that its frequency is low in kidney transplant recipients when compared with liver transplant recipients. We suggest that a rational approach to patient selection, based on a combination of clinical and biological characteristics, may help to provide a safer method for identification of patients potentially suitable for immunosuppressive drug weaning procedures.