Céline Guilbeau-Frugier

Eculizumab Improves Posttransplant Thrombotic Microangiopathy Due to Antiphospholipid Syndrome Recurrence but Fails to Prevent Chronic Vascular Changes

Thrombotic microangiopathy (TMA) is one of the hallmark vascular lesions of antiphospholipid syndrome nephropathy (APSN). These lesions are at high risk of recurrence after kidney transplantation. The complement pathway is thought to be active in this process. We used eculizumab to treat three consecutive kidney transplant recipients with posttransplant TMA due to APSN recurrence that was resistant to plasmapheresis and explored the complement deposition and apoptotic and vascular cell markers on the sequential transplant biopsies. Treatment with eculizumab resulted in a rapid and dramatic improvement of the graft function in all three patients and in improvement of the TMA lesions within the graft. None of these patients had TMA flares after eculizumab was withdrawn. At the time of TMA diagnosis, immunofluorescence studies revealed intense C5b‐9 and C4d depositions at the endothelial cell surface of the injured vessels. Moreover, C5b‐9 colocalized with vessels exhibiting a high rate of apoptotic cells. Examination of sequential biopsies during eculizumab therapy showed that TMA lesions, C4d and apoptotic markers were rapidly cleared but the C5b‐9 deposits persisted for several months as a footprint of the TMA. Finally, we noticed that complement inhibition did not prevent the development of the chronic vascular changes associated with APSN. Eculizumab seems to be an efficient method for treating severe forms of posttransplant TMA due to APSN recurrence. Terminal complement inhibition does not prevent the development of chronic APSN.

Prevalence, incidence and risk factors for donor-specific anti-HLA antibodies in maintenance liver transplant patients.

Although large retrospective studies have identified the presence of donor‐specific antibodies (DSAs) to be a risk factor for rejection and impaired survival after liver transplantation, the long‐term predicted pathogenic potential of individual DSAs after liver transplantation remains unclear. We investigated the incidence, prevalence and consequences of DSAs in maintenance liver transplant (LT) recipients. Two hundred sixty‐seven LT recipients, who had undergone transplantation at least 6 months previously and had been screened for DSAs at least twice using single‐antigen bead technology, were included and tested annually for the presence of DSAs. At a median of 51 months (min–max: 6–220) after an LT, 13% of patients had DSAs. At a median of 36.5 months (min–max: 2–45) after the first screening, 9% of patients have developed de novo DSAs. The sole predictive factor for the emergence of de novo DSAs was retransplantation (OR 3.75; 95% CI 1.28–11.05, p = 0.025). Five out of 21 patients with de novo DSAs (23.8%) developed an antibody‐mediated rejection. Fibrosis score was higher among patients with DSAs. In conclusion, monitoring for the development of DSAs in maintenance LT patients is useful in case of graft dysfunction and to identify patients with a high risk of developing liver fibrosis.

Long term outcomes of transplantation using kidneys from expanded criteria donors: prospective, population based cohort study.

Objectives To assess the long term outcomes of transplantation using expanded criteria donors (ECD; donors aged ≥60 years or aged 50-59 years with vascular comorbidities) and assess the main determinants of its prognosis. Design Prospective, population based cohort study. Setting Four French referral centres. Participants Consecutive patients who underwent kidney transplantation between January 2004 and January 2011, and were followed up to May 2014. A validation cohort included patients from another four referral centres in France who underwent kidney transplantation between January 2002 and December 2011. Main outcome measures Long term kidney allograft survival, based on systematic assessment of donor, recipient, and transplant clinical characteristics; preimplantation biopsy; and circulating levels of donor specific anti-HLA (human leucocyte antigen) antibody (DSA) at baseline. Results The study included 6891 patients (2763 in the principal cohort, 4128 in the validation cohort). Of 2763 transplantations performed, 916 (33.2%) used ECD kidneys. Overall, patients receiving ECD transplants had lower allograft survival after seven years than patients receiving transplants from standard criteria donors (SCD; 80% v 88%, P<0.001). Patients receiving ECD transplants who presented with circulating DSA at the time of transplantation had worse allograft survival after seven years than patients receiving ECD kidneys without circulating DSA at transplantation (44% v 85%, P<0.001). After adjusting for donor, recipient, and transplant characteristics, as well as preimplantation biopsy findings and baseline immunological parameters, the main independent determinants of long term allograft loss were identified as allocation of ECDs (hazard ratio 1.84 (95% confidence interval 1.5 to 2.3); P<0.001), presence of circulating DSA on the day of transplantation (3.00 (2.3 to 3.9); P<0.001), and longer cold ischaemia time (>12 h; 1.53 (1.1 to 2.1); P=0.011). Recipients of ECD kidneys with circulating DSA showed a 5.6-fold increased risk of graft loss compared with all other transplant therapies (P<0.001). ECD allograft survival at seven years significantly improved with screening and transplantation in the absence of circulating DSA (P<0.001) and with shorter (<12 h) cold ischaemia time (P=0.030), respectively. This strategy achieved ECD graft survival comparable to that of patients receiving an SCD transplant overall, translating to a 544.6 allograft life years saved during the nine years of study inclusion time. Conclusions Circulating DSA and cold ischaemia time are the main independent determinants of outcome from ECD transplantation. Allocation policies to avoid DSA and reduction of cold ischaemia time to increase efficacy could promote wider implement of ECD transplantation in the context of organ shortage and improve its prognosis.

Incidence of donor‐specific antibodies in kidney transplant patients following conversion to an everolimus‐based calcineurin inhibitor‐free regimen

Scarce data exist regarding the incidence of donor‐specific antibodies (DSAs) in kidney transplant patients receiving everolimus‐based immunosuppression without calcineurin inhibitors (CNIs). The aim of this retrospective case–control study was to compare the incidence of de novo DSAs in patients converted to an everolimus‐based regimen without CNIs with that seen in patients maintained on CNIs. Sixty‐one DSA‐free kidney transplant patients who had been converted to an everolimus‐based regimen (everolimus group) were compared to 61 other patients maintained on CNIs‐based regimen (control group). Patients were matched according to age, gender, induction therapy, date of transplantation, and being DSA‐free at baseline. At last follow‐up, the incidence of DSAs was 9.8% in the everolimus group and 5% in the control group (p = ns). In the everolimus group, the increased incidence of DSAs between baseline and last follow‐up was statistically significant. Antibody‐mediated rejection occurred in 6.5% in the everolimus group and 0% in the CNIs group. The incidence of DSAs is numerically increased in kidney transplant patients treated with an everolimus‐based without CNIs. A study including a larger number of patients is required to determine whether a CNI‐free everolimus‐based immunosuppression significantly increases DSAs formation.

De novo donor-specific anti-HLA antibodies mediated rejection in liver-transplant patients.

The incidence and consequences of de novo donor‐specific anti‐HLA antibodies (DSAs) after liver transplantation (LT) are not well known. We investigated the incidence, risk factors, and complications associated with de novo DSAs in this setting. A total of 152 de novo liver‐transplant patients, without preformed anti‐HLA DSAs, were tested for anti‐HLA antibodies, with single‐antigen bead technology, before, at transplantation, at 1, 3, 6 and 12 months after transplantation, and thereafter annually and at each time they presented with increased liver‐enzyme levels until the last follow‐up, that is, 34 (1.5–77) months. Twenty‐one patients (14%) developed de novo DSAs. Of these, five patients had C1q‐binding DSAs (24%). Younger age, low exposure to calcineurin inhibitors, and noncompliance were predictive factors for de novo DSA formation. Nine of the 21 patients (43%) with de novo DSAs experienced an acute antibody‐mediated rejection (AMR). Positive C4d staining was more frequently observed in liver biopsies of patients with AMR (9/9 vs. 1/12, P < 0.0001). Eight patients received a B‐cell targeting therapy, and one patient received polyclonal antibodies. Only one patient required retransplantation. Patient‐ and graft‐survival rates did not differ between patients with and without DSAs. In conclusion, liver‐transplant patients with liver abnormalities should be screened for DSAs and AMR.

Successful treatment of hepatitis E virus-associated cryoglobulinemic membranoproliferative glomerulonephritis with ribavirin.

Hepatitis E virus genotype‐3 (HEV3) infection can cause chronic hepatitis in immunosuppressed patients and induce extra‐hepatic manifestations, such as neurological symptoms, kidney injuries, and immune‐mediated thrombocytopenia. Very few cases of HEV‐induced kidney manifestations have been reported. Herein, we report, for the first time, a case of de novo membranoproliferative glomerulonephritis that occurred in a kidney transplant patient who developed a chronic HEV3 infection, which was successfully treated with ribavirin.

Belatacept in recurrent focal segmental glomerulosclerosis after kidney transplantation

Dear Sir, Recurrence of primary focal segmental glomerulosclerosis (FSGS) occurs in approximately 40% of patients after kidney transplantation and no efficient treatment exists as yet [1]. Recently, Yu et al. [2] have shown that five patients with recurrent FSGS after kidney transplantation were successfully treated with only one or two doses of abatacept, a B7-1 blocker. Herein, we report the outcome of five kidney transplant patients who were given long-term treatment with belatacept, a B7-1 blocker that binds approximately fourfold more avidly to CD86 and approximately twofold more avidly to CD80 than abatacept, for the recurrence of FSGS. Five kidney transplant patients experienced recurrence of FSGS within the first week after transplantation. Two were undergoing a second transplant and had lost their first kidney allograft from FSGS recurrence. At transplantation, all patients had received a prophylactic protocol for FSGS recurrence that included plasmapheresis or immunoadsorption before transplantation, rituximab (375 mg/m before transplantation and at 1 week later), and intravenous cyclosporine A was started at least 12 h before transplantation if it was a deceased donor and 1 week before transplantation in cases of living donation. Cyclosporine A therapy was continued for 10 days after transplantation (target circulating level 250–300 ng/ml) for all patients (Table 1). After FSGS had recurred, four were treated by plasmapheresis or immunoadsorption, three with rituximab, four with galactose, and all received full-dose angiotensin-converting enzyme inhibitors (ACEi). Because of persistent heavy proteinuria, these therapies (except for ACEi) were stopped and belatacept was started. In the fifth patient, recurrence of FSGS was mild and belatacept was immediately started without using any of the other therapies. As has been previously reported [3], belatacept was given at the dose of 5 mg/kg on days 0, 15, and 30, and then monthly. All patients were also given mycophenolic acid (1 g/day) and steroids (5 mg/day). In addition, three patients, who were highly sensitized, were given low-dose tacrolimus (target trough level 3–5 ng/ml). None of these patients presented with antibody-mediated rejection (AMR) before the initiation of belatacept. Kidney biopsies that were performed before the initiation of belatacept showed features of FSGS in four patients without any signs of AMR. B7-1 immunostaining was found to be negative in all patients. After a median follow-up of 11 (6–12) months, the urinary albumin-to-creatinine ratio was slightly decreased in two patients. It remained stable in another patient. Kidney function declined in the two other patients and both had to restart dialysis at 6 and 12 months after having started belatacept. No adverse events or acute rejection episodes were observed during belatacept therapy. In contrast to the study by Yu et al. [2], but similar to the report by Alachkar et al. [4] who treated five kidney transplant patients with FSGS recurrence with B7-1 blockers as well as a recent pediatric case series [5], we found that treating kidney transplant patients with FSGS recurrence with belatacept was unsuccessful: mainly in those patients with heavy proteinuria that already had severe histological injuries. Further studies are required to assess the efficacy to B7-1 blockers in the setting of post-transplant FSGS recurrence.

Kidney histology and function in liver transplant patients

BACKGROUND Chronic kidney disease is a common complication after liver transplantation. However, few reports regarding kidney histology exist for this setting. METHODS Inulin clearance was measured and a kidney biopsy was performed in 99 patients at 60 ± 48 months after liver transplantation. Kidney biopsies were scored according to the Banff classification, and interstitial fibrosis was measured by a computerized quantitative method. RESULTS There was a steep decrease in kidney function within the first 6 months following transplantation, but this lessened thereafter. At kidney biopsy, inulin clearance and estimated glomerular filtration rate (eGFR) (using the abbreviated Modification of Diet in Renal Disease equation) were highly correlated (r(2) = 0.47, P < 0.0001). A decrease in eGFR at 6 months post-transplant was the sole predictive factor for inulin clearance of < 60 mL/min/1.73 m(2) at 5 years post-transplant. Few patients had a specific pattern of kidney histopathology and all patients had complex primary lesions. Lowered eGFR at 6 months post-transplant was a predictive factor for > 50% sclerotic glomeruli on the kidney biopsy. The duration of tacrolimus therapy, as compared to cyclosporine A, was a protective factor for < 20% interstitial fibrosis on the kidney biopsy. CONCLUSION In the setting of liver transplantation, this is the largest kidney-histology study to confirm that histological kidney lesions are complex, multiple and interrelated. Kidney function at 6 months post-transplant can predict long-term kidney function and histology.

Polyoma BK virus-associated nephropathy in kidney-transplant patients: effects of leflunomide on T-cell functions and disease outcome.

BACKGROUND In kidney-transplant recipients, leflunomide has been shown to be efficient for treating polyomavirus BK virus-associated-nephropathy (PVAN). However, it is unknown whether the beneficial effect of leflunomide is related to it having a lower immunosuppressive effect than mycophenolate mofetil (MMF), or to its anti-viral activity. The aim of this study was to assess i) T-cell functions before and after conversion from MMF to leflunomide in kidney-transplant patients with PVAN, and ii) effects of leflunomide on PVAN outcome. PATIENTS AND METHODS Twelve patients were enrolled in this study. At PVAN diagnosis, MMF was replaced by leflunomide. Other immunosuppressive drug doses and levels were maintained unchanged. T-cell functions, i.e., intralymphocyte cytokine expression (IL-2 and TNF-alpha), T-cell activation [i.e., transferrin receptor (CD71) and interleukin (IL)-2 alpha-chain (CD25) expression], and T-cell proliferation were measured using a flow-cytometry whole-blood assay before and at one month after conversion. RESULTS Despite a slight decrease in tacrolimus trough levels, no significant change in T-cell-function biomarkers was observed after conversion. After a follow-up of 6 (4-30) months, five patients were cleared of the virus, and decreased viral load was observed in four patients. Only one patient suffered a graft loss. No difference in immunological parameters was observed between patients who were cleared or not of BKV. CONCLUSION Results of this pilot study suggest that the potential benefits of leflunomide to treat PVAN in kidney-transplant patients is not related to reduced immunosuppression induced by replacing MMF by leflunomide. Virological studies are required to determine the anti-BKV effect of leflunomide.

Low- versus high-dose rituximab for antibody-mediated rejection after kidney transplantation

Dear Sir The treatment of antibody-mediated rejection (AMR) after kidney transplantation is based on the association of plasma exchange (PE) with or without rituximab, with or without intravenous immunoglobulins (Iv-Ig) [1–3]. However, if used, the optimal dose of rituximab is still unknown. Furthermore, an increased risk of infection has been reported in kidney-transplant patients receiving rituximab, mainly when combined with polyclonal antibodies [4]. Here, we compared the efficacy and safety of low-dose (375 mg/m2/week for 2 weeks) to high-dose (375 mg/m2/ week for 3–5 weeks, median 4) rituximab given for AMR after kidney transplantation. Between 03/2004 and 01/2011, 39 kidney-transplant patients experienced an AMR, defined by a decreased glomerular filtration rate (GFR), histological features of humoral rejection, positive C4d staining, and the presence of donor-specific antibodies. AMR occurred 46 (1–417) days after transplantation. Initially, high doses of rituximab were given to 22 patients (group I) whereas 17 other patients received later and lower doses of rituximab (group II). Results for 22 of the 39 patients have been previously reported [2]. The patients’ characteristics are presented in Table 1. All patients received steroid pulses (10 mg/kg/day for 3 days), PE, rituximab, as well as Pneumocystis jiroveci and cytomegalovirus prophylaxis for 12 months. Rabbit anti-thymocyte globulins (Thymoglobulin; GenzymeSanofi Lyon, France, 1.25 mg/kg/day for 5 days) or OKT3 (5 mg/day for 5 days) was given to patients who had steroid-resistant cellular and humoral rejection. Before AMR, the proportion of patients receiving tacrolimus was higher in group II; however, after AMR, all patients received tacrolimus, mycophenolic acid, and steroids. The time since the AMR to the last follow-up was significantly longer for patients in group I. At last follow-up, patientand graft-survival rates were similar in both groups, respectively, at 91% and 59% for group I, and 82.3% and 58.8% for group II. Death-censored graft survivals were 68.2% in group I and 70.6% in group II. At the AMR episode, 19% of patients from group I and 56% from group II required dialysis (P = 0.03). In patients not requiring dialysis at diagnosis of AMR, estimated MDRD GFR was 28 (15–56) ml/min in group I and 34 (14– 107) ml/min in group II. At last follow-up, eGFR was 35 (21–58) ml/min in group I and 44 (21–90) ml/min in group II, P = ns. The incidence of a bacterial or viral infection did not differ between groups during the follow-up period, although the incidence of fungal infection was lower in the low-dose rituximab group. Receiving low-dose rituximab (versus receiving high-dose rituximab) was the sole independent protective factor for fungal infection (OR: 0.11, CI95% 0.012–0.986, P = 0.05). Whether rituximab has a beneficial role on treating AMR is still unknown [5], although small series suggest it may have [6]. Here, despite the differences in length of followup and the small number of patients, the outcomes were similar regardless of whether rituximab was used at highor low-dose. However, in the absence of histological data, their impact on chronic AMR is unknown. Less fungal infections occurred in patients receiving low-doses of rituximab.