Arnaud Del Bello

Donor-Specific Antibodies after Ceasing Immunosuppressive Therapy, with or without an Allograft Nephrectomy

BACKGROUND AND OBJECTIVES Within the last few years, anti-human leukocyte antigen detection assays have significantly improved. This study asked, using the Luminex single-antigen assay, whether an allograft nephrectomy allowed donor-specific alloantibodies to appear that were not previously detected in the serum when the failed kidney was still in place. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS After losing the kidney allograft and stopping immunosuppressive therapy, the proportions of donor-specific alloantibodies and nondonor-specific alloantibodies were compared in patients who had (n=48; group I) and had not (n=21; group II) undergone an allograft nephrectomy. Allograft nephrectomies were performed at 150 days after kidney allograft loss, and the time between allograft nephrectomy and last follow-up was 538 ± 347 days. RESULTS At kidney allograft loss, donor-specific alloantibodies were detected in three group II patients (14.2%) and six group I patients (12.5%). At last follow-up, donor-specific alloantibodies were detected in 11 patients (52.4%) without and 39 patients (81%) with an allograft nephrectomy (P=0.02). Anti-human leukocyte antigen class I donor-specific alloantibodies were positive in 23.8% of group II and 77% of group I patients (P<0.001); anti-human leukocyte antigen class II donor-specific alloantibodies were positive in 42.8% of group II and 62.5% of group I patients. Independent predictive factors for developing donor-specific alloantibodies after losing kidney allograft and stopping immunosuppressants were number of anti-human leukocyte antigen A/B mismatches at transplantation (zero versus one or more) and allograft nephrectomy. CONCLUSIONS The development of donor-specific alloantibodies was significantly greater in patients with a failed kidney who had undergone an allograft nephrectomy compared with those patients who had not undergone allograft nephrectomy.

Hepatitis E virus-induced severe myositis

Fig. 1. Outcome of biochemical and virological parameters. To the Editor: Genotype 3 hepatitis E virus (HEV3) infection is responsible for self-limiting acute hepatitis, chronic HEV3 infection leading to cirrhosis in immunosuppressed patients, and several extra-hepatic manifestations, i.e., neurological symptoms, kidney injury, and severe thrombocytopenia [1–5]. Ribavirin therapy has been shown to be an efficient therapy for chronic HEV infection [6,7]. Herein, we report on a first case of Guillain–Barré syndrome associated with severe necrotizing myositis that occurred in a liver-transplant patient in acute HEV-infection phase, who then recovered after ribavirin therapy. A 65-year-old liver-transplant male presented, 7 years after transplantation for alcoholic liver disease, with an autochthonous acute HEV infection (Fig. 1): jaundice, increased liverenzyme levels, positive serum HEV RNA (126,000 copies/ml, genotype 3f), and positive anti-HEV IgG and IgM (Wantai Biologic Pharmacy Enterprise, Beijing, People’s Republic of China). All other causes of hepatitis were ruled out. The source of HEV infection has not been clearly identified. However, the patient had eaten undercooked pork meat. He was receiving cyclosporine A (C2 level at 600 ng/ml), mycophenolatemofetil, and steroids. Cyclosporine A doses were dramatically decreased (C2 level at 300 ng/ml). Ten days later, he was unable to stand upright. Neurological examination showed severe quadriparesis, with proximal muscle weakness and abolition of biceps, patellar, and Achilles’ tendon reflexes, as well as a right lower facial palsy. Creatine kinase (CK) level was increased to 191,603 IU/ L (normal <170 IU/L). Electrophysiological studies showed signs of peripheral demyelinating polyradiculopathy with abolition or prolongation of F-wave responses and sensory conduction was altered more in upper limbs. At rest, needle electromyography showed diffuse abnormal spontaneous activity in all four limbs. Cerebrospinal-fluid (CSF) analysis showed elevated protein level (0.64 g/L), no leukocytes, and no HEV RNA, whereas serum HEV RNA was still positive (49,600 copies/ml). The CSF to serum-albumin ratio was 12.81. The CSF (IgG:albumin) to serum (IgG:albumin) ratio was 0.47. Cryoglobulinemia, serum anti-ganglioside (GM1, GM-2, GM-3, GM4, GD1A, GD1B, GD2, GD3, GT1A, GD1B, GQ1B) antibodies, anti-myelin-associated glycoprotein antibodies, as well as serum and CSF onconeuronal antibodies, were negative. A biopsy specimen of the left bicep brachial muscle showed myopathic changes, with a significant percentage of necrotic muscle fibers ( 10%) and some inflammatory elements. There was no capillary thickening. The day after admission, he developed acute respiratory failure that required mechanical ventilation. Because of suspected HEV-induced Guillain–Barré syndrome associated with severe myositis, mycophenolatemofetil was withdrawn and the patient was given intravenous immunoglobulins (1 g/kg/d for 2 days) and ribavirin therapy [400 mg/d adapted to his glo-

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.

Anti-human leukocyte antigen immunization after early allograft nephrectomy.

Introduction The occurrence of de novo anti-human leukocyte antigen (HLA) antibodies and donor-specific antibodies (DSAs) after early graft loss is not well known. The aims of this single-center study were to evaluate the incidence of de novo DSAs and non-DSA anti-HLA antibodies after allograft nephrectomy for early graft loss and to seek the predictive factors for the development of DSAs. Materials and Methods Thirty-two patients, who experienced an early graft loss (<3 months after transplantation) and required an allograft nephrectomy, and who were considered for retransplantation, were included in the study. Anti-HLA antibodies were assessed, using the Luminex assay, before transplantation, on day 15 and at months 1, 3, 6, and 9 after the nephrectomy, and then every 3 to 6 months until the last follow-up. Results The median time between transplantation and allograft nephrectomy was 2.5 (0–81) days. The median follow-up was 335 (30–1441) days. At month 9, postallograft nephrectomy, the incidence of DSAs was 56.6% (17/30). Anti-HLA class I and class II DSAs were detected, respectively, in 33.3% (10/30) and 30% (9/30) of patients. The incidence of de novo non-DSA anti-HLA antibodies was 64% (19/30): of these, 83.3% reacted to the donors’ epitopes. Induction therapy (type and dose) and the time between transplantation and allograft nephrectomy did not influence the incidence of DSAs. No independent predictive factor for the development of DSAs was identified. Conclusion Even after a short transplantation period, DSAs and non-DSA anti-HLA antibodies may develop in more than 50% of patients whose immunosuppression has been stopped after an allograft nephrectomy.

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.

Pregnancy after kidney transplantation: outcome and anti-human leucocyte antigen alloimmunization risk

BACKGROUND Kidney transplantation increases the chances for pregnancy and live birth for women with end-stage kidney disease. The aims of this study were to describe the outcomes of pregnancies in women with a kidney transplant and to evaluate the impact on anti-human leucocyte antigen (HLA) alloimmunization. METHODS We analysed 61 pregnancies that occurred in 46 patients after having excluded 10 miscarriages during the first trimester and 10 other pregnancies from which important data were missing. Anti-HLA antibodies were screened using the Luminex assay. RESULTS Overall, the live birth rate was 83% (94% after exclusion of miscarriages during the first trimester). Pre-eclampsia and gestational diabetes occurred in 26 and 21% of cases, respectively. The use of tacrolimus was an independent predictive factor for gestational diabetes. Twenty-four newborns (42%) were premature (<37 weeks). The median birth weight was 2720 (1040-3730) g. Nine newborns (15%) had low birth weights (<2.5 kg). At least one severe complication occurred in 56% of pregnancies. A high glomerular-filtration rate (GFR) before pregnancy was the sole independent protective factor that avoided a severe complication. Death-censored kidney-allograft survival was 80.4% at 6 years. De novo donor-specific anti-HLA antibodies were detected after only 5.9% of pregnancies: for two women, the father had the same HLA antigens as those from the deceased organ donor. The determination of the HLA of the father before pregnancy can better inform the woman about the possible impact of pregnancy on her kidney-allograft function. CONCLUSIONS Despite many complications, the outcomes for pregnancy and kidney allografts are good. The risk of anti-HLA alloimmunization was low.

Donor-specific antibodies and liver transplantation.

In contrast to other types of organ transplantation, liver-transplant recipients used to be considered highly resistant to donor-specific antibodies (DSAs). Consequently, most transplant programs did not consider the presence of DSAs at transplantation or during the follow-up. However, since the early 1990s, antibody-mediated pathological lesions have been recognized in ABO-incompatible liver-transplant recipients. Recent data confirm the detrimental effect of preformed and de novo DSAs in ABO-compatible liver transplantation, with inferior clinical outcomes in patients presenting with circulating antibodies. Acute antibody-mediated rejection (AMR), plasma-cell hepatitis, biliary stricture, but also long-term complications, such as chronic rejection, liver ductopenia, and graft fibrosis, are now recognized to be associated with DSAs. Moreover, some non-HLA DSAs are suspected to induce graft dysfunction. Clinical, biological, and histological patterns within AMR need to be clarified. Treatment of these complications has yet to be defined. This article summarizes recent advances concerning the impact of preformed and de novo DSAs in liver transplantation, it defines the complications associated with DSAs, and discusses the potential strategies to manage patients with such complications.

Calcineurin inhibitor‐sparing regimens based on mycophenolic acid after kidney transplantation

The use of calcineurin inhibitors (CNIs) has dramatically reduced the number of acute rejections and improved kidney allograft survival. However, CNIs can also cause kidney damage and several adverse events. This has prompted transplant physicians to use CNI‐sparing regimens. CNI withdrawal, minimization, or avoidance protocols have been conducted using mycophenolic acid (MPA), and/or mammalian‐target‐of‐rapamycin inhibitors, and/or belatacept. Herein, we review the outcomes of minimizing, withdrawing, or avoiding CNIs when giving mycophenolic acid to de novo and maintenance kidney transplant patients. Protocols on CNI withdrawal, when based on MPA without mammalian‐target‐of‐rapamycin inhibitors (mTORi) or belatacept, in de novo and maintenance kidney transplant patients, are associated with an increased risk of acute rejection. Consequently, these strategies have been abandoned and are not recommended. Protocols on CNI minimization show a beneficial impact of kidney function and acceptable acute rejection rates mainly in patients who have been recipients of a graft for >3–5 years. However, no significant improvement to graft survival has been observed.

Beneficial Effect of Conversion to Belatacept in Kidney-Transplant Patients with a Low Glomerular-Filtration Rate

Belatacept has been found to be efficient at preserving good kidney function in maintenance kidney-transplant patients. Herein, we report on the use of belatacept as a rescue therapy for two kidney-transplant patients presenting with severe adverse events after treatment with calcineurin inhibitors (CNIs) and mammalian target-of-rapamycin (mTOR) inhibitors. Two kidney-transplant patients developed severely impaired kidney function after receiving CNIs. The use of everolimus was associated with severe angioedema. Belatacept was then successfully used to improve kidney function in both cases, even though estimated glomerular-filtration rate before conversion was <20 mL/min. These case reports show that belatacept can be used as a rescue therapy, even if kidney function is very low in kidney-transplant patients who cannot tolerate CNIs and/or mTOR inhibitors.