Use of a Belatacept-based Immunosuppression for Kidney Transplantation From Donors After Circulatory Death: A Paired Kidney Analysis.

Background: Efficacy and safety of belatacept have not been specifically reported for kidney transplantations from donors after circulatory death. Methods: In this retrospective multicenter paired kidney study, we compared the outcome of kidney transplantations with a belatacept-based to a calcineurin inhibitor (CNI)-based immunosuppression. We included all kidney transplant recipients from donors after uncontrolled or controlled circulatory death performed in our center between February 2015 and October 2020 and treated with belatacept (n = 31). The control group included the recipients of the contralateral kidney that were treated with CNI in 8 other centers (tacrolimus n = 29, cyclosporine n = 2). Results: There was no difference in the rate of delayed graft function. A higher incidence of biopsy-proven rejections was noted in the belatacept group (24 versus 6 episodes). Estimated glomerular filtration rate (eGFR) was significantly higher in the belatacept group at 3-, 12-, and 36-mo posttransplant, but the slope of eGFR was similar in the 2 groups. During a mean follow-up of 4.1 y, 12 patients discontinued belatacept and 2 patients were switched from CNI to belatacept. For patients who remained on belatacept, eGFR mean value and slope were significantly higher during the whole follow-up. At 5 y, eGFR was 80.7 ± 18.5 with belatacept versus 56.3 ± 22.0 mL/min/1.73 m2 with CNI (P = 0.003). No significant difference in graft and patient survival was observed. Conclusions: The use of belatacept for kidney transplants from either uncontrolled or controlled donors after circulatory death resulted in a better medium-term renal function for patients remaining on belatacept despite similar rates of delayed graft function and higher rates of cellular rejection.

Development and validation of a new equation based on plasma creatinine and muscle mass assessed by CT scan to estimate glomerular filtration rate: a cross-sectional study.

Background: Inter-individual variations of non-glomerular filtration rate (GFR) determinants of serum creatinine, such as muscle mass, account for the imperfect performance of estimated GFR (eGFR) equations. We aimed to develop an equation based on creatinine and total lumbar muscle cross-sectional area measured by unenhanced computed tomography scan at the third lumbar vertebra. Methods: The muscle mass-based eGFR (MMB-eGFR) equation was developed in 118 kidney donor candidates (iohexol clearance) using linear regression. Validation cohorts included 114 healthy subjects from another center (51Cr-EDTA clearance, validation population 1), 55 patients with chronic diseases (iohexol, validation population 2), and 60 patients with highly discordant creatinine and cystatin C-based eGFR, thus presumed to have atypical non-GFR determinants of creatinine (51Cr-EDTA, validation population 3). Mean bias was the mean difference between eGFR and measured GFR, precision the standard deviation (SD) of the bias, and accuracy the percentage of eGFR values falling within 20% and 30% of measured GFR. Results: In validation population 1, performance of MMB-eGFR was not different from those of CKD-EPICr2009 and CKD-EPICr2021. In validation population 2, MMB-eGFR was unbiased and displayed better precision than CKD-EPICr2009, CKD-EPICr2021 and EKFC (SD of the biases: 13.1 vs 16.5, 16.8 and 15.9 mL/min/1.73 m2). In validation population 3, MMB-eGFR had better precision and accuracy {accuracy within 30%: 75.0% [95% confidence interval (CI) 64.0-86.0] vs 51.5% (95% CI 39.0-64.3) for CKD-EPICr2009, 43.3% (95% CI 31.0-55.9) for CKD-EPICr2021, and 53.3% (95% CI 40.7-66.0) for EKFC}. Difference in bias between Black and white subjects was -2.1 mL/min/1.73 m2 (95% CI -7.2 to 3.0), vs -8.4 mL/min/1.73 m2 (95% CI -13.2 to -3.6) for CKD-EPICr2021. Conclusion: MMB-eGFR displayed better performances than equations based on demographics, and could be applied to subjects of various ethnic backgrounds.

Prognostic value of complement serum C3 level and glomerular C3 deposits in anti-glomerular basement membrane disease.

Background and objectives: Activation of the complement system is involved in the pathogenesis of anti-glomerular basement membrane (anti-GBM) disease. Glomerular deposits of complement 3 (C3) are often detected on kidney biopsies. The primary objective of this study was to analyze the prognostic value of the serum C3 level and the presence of C3 glomerular deposits in patients with anti-GBM disease. Methods: We conducted a retrospective cohort study of 150 single-positive patients with anti-GBM disease diagnosed between 1997 and 2017. Patients were categorized according to the serum C3 level (forming a low C3 (C3<1.23 g/L) and a high C3 (C3≥1.23 g/L) groups) and positivity for C3 glomerular staining (forming the C3+ and C3- groups). The main outcomes were kidney survival and patient survival. Results: Of the 150 patients included, 89 (65%) were men. The median [interquartile range (IQR)] age was 45 [26-64]. At diagnosis, kidney involvement was characterized by a median [IQR] peak serum creatinine (SCr) level of 578 [298-977] µmol/L, and 106 (71%) patients required dialysis. Patients in the low C3 group (72 patients) had more severe kidney disease at presentation, as characterized by higher prevalences of oligoanuria, peak SCr ≥500 µmol/L (69%, vs. 53% in the high C3 group; p=0.03), nephrotic syndrome (42%, vs. 24%, respectively; p=0.02) and fibrous forms on the kidney biopsy (21%, vs. 8%, respectively; p=0.04). Similarly, we observed a negative association between the presence of C3 glomerular deposits (in 52 (41%) patients) and the prevalence of cellular forms (83%, vs. 58% in the C3- group; p=0.003) and acute tubulo-interstitial lesions (60%, vs. 36% in the C3- group; p=0.007). When considering patients not on dialysis at diagnosis, the kidney survival rate at 12 months was poorer in the C3+ group (50% [25-76], vs. 91% [78-100] in the C3- group; p=0.01), with a hazard ratio [95% confidence interval] of 5.71 [1.13-28.85] (p=0.04, after adjusting for SCr). Conclusion: In patients with anti-GBM disease, a low serum C3 level and the presence of C3 glomerular deposits were associated with more severe disease and histological kidney involvement at diagnosis. In patients not on dialysis at diagnosis, the presence of C3 deposits was associated with worse kidney survival.

Clinical and Prognostic Factors in Patients with IgG4-Related Kidney Disease.

BACKGROUND: IgG4-related kidney disease is a major manifestation of IgG4-related disease, a systemic fibroinflammatory disorder. However, the clinical and prognostic kidney-related factors in patients with IgG4-related kidney disease are insufficiently defined. METHODS: We conducted an observational cohort study using data from 35 sites in two European countries. Clinical, biologic, imaging, and histopathologic data; treatment modalities; and outcomes were collected from medical records. Logistic regression was performed to identify the possible factors related to an eGFR ≤30 ml/min per 1.73 m 2 at the last follow-up. Cox proportional hazards model was performed to assess the factors associated with the risk of relapse. RESULTS: We studied 101 adult patients with IgG4-related disease with a median follow-up of 24 (11-58) months. Of these, 87 (86%) patients were male, and the median age was 68 (57-76) years. Eighty-three (82%) patients had IgG4-related kidney disease confirmed by kidney biopsy, with all biopsies showing tubulointerstitial involvement and 16 showing glomerular lesions. Ninety (89%) patients were treated with corticosteroids, and 18 (18%) patients received rituximab as first-line therapy. At the last follow-up, the eGFR was below 30 ml/min per 1.73 m 2 in 32% of patients; 34 (34%) patients experienced a relapse, while 12 (13%) patients had died. By Cox survival analysis, the number of organs involved (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.01 to 1.55) and low C3 and C4 concentrations (HR, 2.31; 95% CI, 1.10 to 4.85) were independently associated with a higher risk of relapse, whereas first-line therapy with rituximab was protective (HR, 0.22; 95% CI, 0.06 to 0.78). At their last follow-up, 19 (19%) patients had an eGFR ≤30 ml/min per 1.73 m 2 . Age (odd ratio [OR], 1.11; 95% CI, 1.03 to 1.20), peak serum creatinine (OR, 2.74; 95% CI, 1.71 to 5.47), and serum IgG4 level ≥5 g/L (OR, 4.46; 95% CI, 1.23 to 19.40) were independently predictive for severe CKD. CONCLUSIONS: IgG4-related kidney disease predominantly affected middle-aged men and manifested as tubulointerstitial nephritis with potential glomerular involvement. Complement consumption and the number of organs involved were associated with a higher relapse rate, whereas first-line therapy with rituximab was associated with lower relapse rate. Patients with high serum IgG4 concentrations (≥5 g/L) had more severe kidney disease.

Conversion to belatacept after lung transplantation: Report of 10 cases.

BACKGROUND: Calcineurin inhibitors (CNIs) remain the cornerstone of maintenance immunosuppression (IS) after lung transplantation (LTx), although CNI-related life-threatening toxic effects may occur. Belatacept, a novel immunosuppressant that blocks a T-cell co-stimulation pathway, is a non-nephrotoxic drug indicated as an alternative to CNIs in kidney Tx. In LTx, there are only a few reports of belatacept conversion as a CNI-free or CNI-sparing IS treatment. METHODS: We reviewed a series of 10 LTx recipients with conversion to a CNI-free belatacept IS regimen within the first year post-LTx (n = 7) or a belatacept/low-dose CNI combination after the first year (n = 3). RESULTS: Use of belatacept was triggered by severe renal failure in 9 patients and under-IS with previous other IS-related toxicities in 1 patient. Mean estimated glomerular filtration rate after starting belatacept significantly improved at 6 months after initiation and at the last-follow-up (p = 0.006, and p = 0.002 respectively). The incidence of recurrent and/or severe acute cellular rejection (ACR) episodes was high in patients with CNI-free belatacept-based IS (n = 4/7). Chronic graft allograft dysfunction developed in 2 of 9 recipients under belatacept IS. Belatacept was stopped in 6 patients because of recurrent/severe ACR (n = 3), recurrent opportunistic infections (n = 1), center modified policy (n = 1), or other cause (n = 1). CONCLUSION: Early conversion to CNI-free belatacept-based IS improved renal function in this series but was counterbalanced by a high incidence of recurrent ACR, including life-threatening episodes. Other studies are needed to better determine the indications for its use after LTx, possibly with lower immunological risk IS regimens, such as CNI-sparing belatacept.

BK virus genotypes and humoral response in kidney transplant recipients with BKV associated nephropathy.

BACKGROUND: Among kidney transplant recipients (KTR) with BK virus associated nephropathy (BKVN), BKV genotypes' evolution and anti-BKV humoral response are not well established. We aim to analyze BKV replication and genetic evolution following transplantation, and characterize concomitant anti-BKV-VP1 humoral response. METHODS: We retrospectively analyzed 32 cases of biopsy-proven BKVN. Stored plasma and kidney biopsies were tested for BKV viral load, and VP1 sequencing performed on positive samples. BKV-VP1 genotype-specific neutralizing antibodies (NAbs) titers were determined at transplantation and BKVN. RESULTS: At the time of BKVN diagnosis, BKV viral load was 8.2 log10 IU/106 cells and 5.4 log10 IU/mL in kidney and plasma, respectively. VP1 sequencing identified the same BKV-subtype in both compartments in 31/32 cases. At the time of transplantation, 8/20 (40%) of biopsies tested positive for BKV detection, whereas concomitant BKV viremia was negative. VP1 sequencing identified a different subtype compared to BKVN in 5/6 of these samples. This was confirmed following transplantation: 8 patients had a BKV+ biopsy before BKV viremia, and VP1 sequencing identified a different subtype compared to BKVN in all of them. After the onset of BKV viremia and prior to BKVN diagnosis, the BKV subtype in BKV+ plasma and kidney biopsy was the same as the one isolated at BKVN. BKV-VP1 NAbs titers were significantly higher at the time of BKVN compared to transplantation (p = .0031), with similar titers across genotypes. CONCLUSION: Altogether, our data suggest that among some KTR with BKVN, the BKV genotype from the donor may not be responsible for BKVN pathogenesis.

Characteristics, risk factors and outcome of BKV nephropathy in kidney transplant recipients: a case-control study.

BACKGROUND: Following kidney transplantation, BK virus associated nephropathy (BKVN) occurs in 1 to 10% of kidney transplant recipients (KTR) and represents a major cause of graft loss. We aim at identifying factors associated with biopsy proven BKVN among KTR. METHODS: We conducted a retrospective case-control study including all KTR with a biopsy-proven diagnosis of BKVN between 2005 and 2019. Clinical characteristics and outcome were described. For each case, one control KTR without BKV infection was identified and matched by age, transplant date, and donor status. Factors associated with BKVN diagnosis were identified using exact conditional logistic regression. Comparative survival was described using Kaplan-Meier estimator. RESULTS: Sixty-four cases of BKVN were identified among 1737 new kidney transplantation (3.7% prevalence). Clinical characteristics did not differ between groups, except for a higher c-PRA among cases. BKVN occurred in a median time of 11 (5-14.5) months after KT, and was associated with a significantly impaired graft function at diagnosis. Following BKVN, 61 (95%) of the patients had immunosuppression reduction, which led to BKV DNAemia resolution in 49% of cases. In multivariate analysis, factors associated with BKVN diagnosis were lymphopenia < 500/mm3 and a prednisone dose > 7.5 mg/day. Median duration of follow-up was 40 months for both groups. BKVN was associated with a significantly increased risk of graft rejection (P = 0.02) and return to dialysis (P = 0.01). CONCLUSIONS: BKVN remains a severe complication in KTR and is associated with an increased risk for acute rejection and return to dialysis. Lymphopenia below 500/mm3 and corticosteroid maintenance therapy are significantly associated with biopsy-proven BKVN diagnosis.

Cryptococcal Meningitis in Kidney Transplant Recipients: A Two-Decade Cohort Study in France.

Cryptococcosis is the third most common cause of invasive fungal infection in solid organ transplant recipients and cryptococcal meningitis (CM) its main clinical presentation. CM outcomes, as well as its clinical features and radiological characteristics, have not yet been considered on a large scale in the context of kidney transplantation (KT). We performed a nationwide retrospective study of adult patients diagnosed with cryptococcosis after KT between 2002 and 2020 across 30 clinical centers in France. We sought to describe overall and graft survival based on whether KT patients with cryptococcosis developed CM or not. Clinical indicators of CNS involvement and brain radiological characteristics were assessed. Eighty-eight cases of cryptococcosis were diagnosed during the study period, with 61 (69.3%) cases of CM. Mortality was high (32.8%) at 12 months (M12) but not significantly different whether or not patients presented with CM. Baseline hyponatremia and at least one neurological symptom were independently associated with CM (p < 0.001). Positive serum cryptococcal antigen at diagnosis was also significantly associated with CM (p < 0.001). On magnetic resonance imaging (MRI), three patterns of brain injury were identified: parenchymal, meningeal, and vascular lesions. Although CM does not affect graft function directly, it entails a grim prognosis.

Estimating Extracellular Fluid Volume in Healthy Individuals: Evaluation of Existing Formulae and Development of a New Equation.

Introduction: Several clinical settings require an accurate estimation of the physiologically expected extracellular fluid volume (ECFV). We aimed to analyze the performances of existing ECFV-estimating equations and to develop a new equation. Methods: The performances of 11 ECFV-estimating equations were analyzed in 228 healthy kidney donor candidates (Bichat Hospital, Paris, France) who underwent ECFV measurement using the distribution volume of 51Cr-labeled EDTA (51Cr-EDTA). An equation was developed using a penalized linear modeling approach (elastic net regression) and externally (Tenon Hospital, Paris, France, N = 142) validated. Results: Participants from Bichat (mean age 45.2 ± 12.0 years, 43.0% men) and Tenon (47.8 ± 10.3 years, 29.6% men) hospitals had a mean measured ECFV of 15.4 ± 2.8 l and 15.1 ± 2.1 l, respectively. Available ECFV-estimating formulae have highly variable precision and accuracy. The new equation incorporating body weight, height, sex, and age had better precision and accuracy than all other equations in the external validation cohort, with a median bias of -0.20 (95% CI: -0.35 to -0.05) l versus -2.63 (-2.87 to -2.42) l to -0.57 (- 0.83 to -0.40) l and 0.21 (0.12 to 0.43) l to 2.89 (2.65 to 3.11) l, for underestimating and overestimating equations, respectively, an interquartile range for the bias of 0.88 (0.70 to 1.08) l versus 0.91 (0.71 to 1.20) l to 1.93 (1.67 to 2.25) l, and an accuracy within 10% of 90.9% (83.8 to 94.4) versus 88.0% (81.0 to 92.3) to 8.5% (4.2 to 13.4). These results were consistent across subgroups defined by sex, body mass index (BMI), body surface area (BSA), age, and ethnicity. Conclusion: We developed and validated a new equation to estimate the individual reference value of ECFV, which is easily usable in clinical practice. Further validation in cohorts including individuals of extreme age and corpulence remains needed.

Long-term survival benefit from dual kidney transplantation using kidneys from donors with very extended criteria-a French cohort between 2002 and 2014.

BACKGROUND: This national multicentre retrospective cohort study aimed to assess the long-term outcomes of dual kidney transplantation (DKT) and compare them with those obtained from single kidney transplantation (SKT). METHODS: Our first analysis concerned all first transplants performed between May 2002 and December 2014, from marginal donors, defined as brain death donors older than 65 years, with an estimated glomerular filtration rate (eGFR) lower than 90 mL/min/1.73 m2. The second analysis was restricted to transplants adequately allocated according to the French DKT program based on donor eGFR: DKT for eGFR between 30 and 60, SKT for eGFR between 60 and 90 mL/min/1.73 m2. Recipients younger than 65 years or with a panel-reactive antibody percentage ≥25% were excluded. RESULTS: The first analysis included 461 DKT and 1131 SKT. DKT donors were significantly older (77.6 versus 74 years), had a more frequent history of hypertension and a lower eGFR (55.1 versus 63.6 mL/min/1.73 m2). While primary nonfunction and delayed graft function did not differ between SKT and DKT, 1-year eGFR was lower in SKT recipients (39 versus 49 mL/min/1.73 m2, P < 0.001). Graft survival was significantly better in DKT, even after adjustment for recipient and donor risk factors. Nevertheless, patient survival did not differ between these groups. The second analysis included 293 DKT and 687 SKT adequately allocated with donor eGFR and displayed similar results but with a smaller benefit in terms of graft survival. CONCLUSIONS: In a context of organ shortage, DKT is a good option for optimizing the use of kidneys from very expanded criteria donors.

Cryptococcus neoformans meningitis in kidney transplant recipients: A diagnostic and therapeutic challenge.

Cryptococcosis is the third most common invasive fungal infection in solid organ transplant recipients. We describe three cases of neuro-meningeal cryptococcosis occurring among kidney transplant (KT) patients, and discuss the diagnostic and therapeutic challenges in this context. Median time from KT to infection was 6 months [range: 3-9]. The most common clinical manifestations at diagnosis were fever (2/3), headache (2/3), and confusion (2/3); none had extra-neurological involvement. CrAg was positive in all cases at diagnosis both in serum and cerebrospinal fluid (CSF). For two patients, analysis of previous samples showed that CrAg was detected in plasma up to 4 weeks before diagnosis. All patients received induction treatment with liposomal amphotericin-B (L-AmB) and flucytosine for a median duration of 10 days [range: 7-14], followed by fluconazole maintenance therapy. Acute kidney injury secondary to L-AmB therapy was observed in only one case, but all patients had a tacrolimus overdose following initiation of maintenance therapy due to drug-drug interactions between fluconazole and tacrolimus. Among KTR, early detection of Cryptococcus meningitis using serum CrAg is possible. Close monitoring of renal function during treatment is essential due to the nephrotoxicity of L-AmB, but also drug-drug interactions between fluconazole and calcineurin inhibitors.

Clinical characteristics, risk factors and outcome of severe Norovirus infection in kidney transplant patients: a case-control study.

BACKGROUND: Human Norovirus (HuNoV) has recently been identified as a major cause of diarrhea among kidney transplant recipients (KTR). Data regarding risk factors associated with the occurrence of HuNoV infection, and its long-term impact on kidney function are lacking. METHODS: We conducted a retrospective case-control study including all KTR with a diagnosis of HuNoV diarrhea. Each case was matched to a single control according to age and date of transplantation, randomly selected among our KTR cohort and who did not develop HuNoV infection. Risk factors associated with HuNoV infection were identified using conditional logistic regression, and survival was estimated using Kaplan-Meier estimator. RESULTS: From January 2012 to April 2018, 72 cases of NoV diarrhea were identified among 985 new KT, leading to a prevalence of HuNoV infection of 7.3%. Median time between kidney transplantation and diagnosis was 46.5 months (Inter Quartile Range [IQR]:17.8-81.5), and the median duration of symptoms 40 days (IQR: 15-66.2). Following diagnosis, 93% of the cases had a reduction of immunosuppression. During follow-up, de novo Donor Specific Antibody (DSA) were observed in 8 (9%) cases but none of the controls (p = 0.01). Acute rejection episodes were significantly more frequent among cases (13.8% versus 4.2% in controls; p = 0,03), but there was no difference in serum creatinine level at last follow-up between the two groups (p = 0.08). Pre-transplant diabetes and lymphopenia below 1000/mm3 were identified as risks factors for HuNoV infection in multivariate analysis. CONCLUSION: HuNoV infection is a late-onset and prolonged infection among KTR. The current management, based on the reduction of immunosuppressive treatment, is responsible for the appearance of de novo DSA and an increase in acute rejection episodes.

Immune Checkpoint Inhibitors in Transplantation-A Case Series and Comprehensive Review of Current Knowledge.

Cancer is a leading cause of morbidity and deaths in solid organ transplant recipients. In immunocompetent patients, cancer prognosis has been dramatically improved with the development of immune checkpoint inhibitors (ICI), as programmed cell death protein 1/programmed death-ligand 1 and cytotoxic T lymphocyte-associated antigen 4 inhibitors, that increase antitumor immune responses. ICI has been developed outside of the scope of transplantation because of the theoretical risk of graft rejection, which has later been confirmed by the publication of several cases and small series. The use of ICI became unavoidable for treating advanced cancers including in organ transplant patients, but their management in this setting remains highly challenging, as to date no strategy to adapt the immunosuppression and to prevent graft rejection has been defined. In this article, we report a monocentric series of 5 solid organ transplant recipients treated with ICI and provide a comprehensive review of current knowledge of ICI management in the setting of solid organ transplantation. Strategies warranted to increase knowledge through collecting more exhaustive data are also discussed.

Severe Infection in Anti-Glomerular Basement Membrane Disease: A Retrospective Multicenter French Study.

In patients presenting with anti-glomerular basement membrane (GBM) disease with advanced isolated kidney involvement, the benefit of intensive therapy remains controversial due to adverse events, particularly infection. We aim to describe the burden of severe infections (SI) (requiring hospitalization or intravenous antibiotics) and identify predictive factors of SI in a large cohort of patients with anti-GBM disease. Among the 201 patients (median [IQR] age, 53 [30-71] years) included, 74 had pulmonary involvement and 127 isolated glomerulonephritis. A total of 161 SI occurred in 116 patients during the first year after diagnosis. These infections occurred during the early stage of care (median [IQR] time, 13 [8-19] days after diagnosis) with mainly pulmonary (45%), catheter-associated bacteremia (22%) and urinary tract (21%) infections. In multivariable analysis, positive ANCA (HR [95\% CI] 1.62 [1.07--2.44]; p = 0.02) and age at diagnosis (HR [95% CI] 1.10 [1.00-1.21]; p = 0.047) remained independently associated with SI. Age-adjusted severe infection during the first three months was associated with an increased three-year mortality rate (HR [95% CI] 3.13 [1.24-7.88]; p = 0.01). Thus, SI is a common early complication in anti-GBM disease, particularly in the elderly and those with positive anti-neutrophil cytoplasmic antibodies (ANCA). No significant association was observed between immunosuppressive strategy and occurrence of SI.

Use of Highly Individualized Complement Blockade Has Revolutionized Clinical Outcomes after Kidney Transplantation and Renal Epidemiology of Atypical Hemolytic Uremic Syndrome.

BACKGROUND: Atypical hemolytic uremic syndrome (HUS) is associated with high recurrence rates after kidney transplant, with devastating outcomes. In late 2011, experts in France recommended the use of highly individualized complement blockade-based prophylaxis with eculizumab to prevent post-transplant atypical HUS recurrence throughout the country. METHODS: To evaluate this strategy's effect on kidney transplant prognosis, we conducted a retrospective multicenter study from a large French nationwide registry, enrolling all adult patients with atypical HUS who had undergone complement analysis and a kidney transplant since January 1, 2007. To assess how atypical HUS epidemiology in France in the eculizumab era evolved, we undertook a population-based cohort study that included all adult patients with atypical HUS (n=397) between 2007 and 2016. RESULTS: The first study included 126 kidney transplants performed in 116 patients, 58.7% and 34.1% of which were considered to be at a high and moderate risk of atypical HUS recurrence, respectively. Eculizumab prophylaxis was used in 52 kidney transplants, including 39 at high risk of recurrence. Atypical HUS recurred after 43 (34.1%) of the transplants; in four cases, patients had received eculizumab prophylaxis and in 39 cases they did not. Use of prophylactic eculizumab was independently associated with a significantly reduced risk of recurrence and with significantly longer graft survival. In the second, population-based cohort study, the proportion of transplant recipients among patients with ESKD and atypical HUS sharply increased between 2012 and 2016, from 46.2% to 72.3%, and showed a close correlation with increasing eculizumab use among the transplant recipients. CONCLUSIONS: Results from this observational study are consistent with benefit from eculizumab prophylaxis based on pretransplant risk stratification and support the need for a rigorous randomized trial.

Kaposi Sarcoma in HIV-positive Solid-Organ Transplant Recipients: A French Multicentric National Study and Literature Review.

BACKGROUND: Kaposi sarcoma is a vascular tumor related to herpesvirus-8 and is promoted by immunosuppression. For the last 15 years, human immunodeficiency virus (HIV) patients have had access to organ transplantation. The dual immunosuppression of HIV and immunosuppressive treatments might increase the risk and severity of Kaposi sarcoma. METHODS: We conducted a multicentric retrospective study by collecting cases from French databases and society members of transplanted patients, among which 7 HIV-infected patients who subsequently developed Kaposi sarcoma were included. RESULTS: In the CRISTAL database (114 511 patients) and the DIVAT (Données Informatisées et VAlidées en Transplantation) database (19 077 patients), the prevalence of Kaposi sarcoma was 0.18% and 0.46%, respectively, in transplanted patients; these values compare with 0.66% and 0.50%, respectively, in transplanted patients with HIV. The median time from HIV infection to Kaposi sarcoma was 20 years. Kaposi sarcoma occurred during the first year after transplantation in most cases, whereas HIV viral load was undetectable. Only 2 patients had visceral involvement. Five patients were treated with conversion of calcineurin inhibitor to mammalian target of rapamycin inhibitor, and 5 patients were managed by decreasing immunosuppressive therapies. At 1 year, 4 patients had a complete response, and 3 had a partial response. CONCLUSIONS: In our study, Kaposi sarcoma in transplanted patients with HIV did not show any aggressive features and was treated with the usual posttransplant Kaposi sarcoma management protocol.

The age-calibrated measured glomerular filtration rate improves living kidney donation selection process.

Recommendations on the glomerular filtration rate (GFR) threshold compatible with living kidney donation are not agreed upon. The recent KDIGO guidelines suggested a reset of the conventional cutoff value of 80 to 90 mL/min/1.73 m2. While GFR physiologically declines with age, it is unclear whether and how age should be taken into account for selecting acceptable pre-donation GFR. In this multicenter retrospective study encompassing 2007 kidney donors in France, we evaluated the impact of age using two threshold measured GFR (mGFR)s (80 and 90 mL/min/1.73 m2). Three groups of donors were defined according to baseline mGFR: below 80, 80-89.9 and 90 mL/min/1.73 m2 or more. Thirty-two percent of donors were selected despite an mGFR below 90 mL/min/1.73 m2. Donors with the lowest mGFR were significantly older (60 ± 9 vs. 47 ± 11 years) and this applied to both male and female donors. The lifetime-standardized renal reserve, defined as the pre-donation mGFR value divided by the expected number of remaining years of life, was similar irrespective of baseline mGFR groups. Similar results were obtained when eGFR was used instead of mGFR. Finally, in a subgroup of 132 donors with repeated mGFR five years after donation, the magnitude of mGFR decrease was similar in all groups (-34.3%, -33.9%, and -34.9% respectively). Thus, the decision to accept individuals with mGFR lower than 90 mL/min/1.73 m2 for kidney donation is highly dependent on the age of the candidate. Hence, threshold values lower than 90 mL/min/1.73 m2 are reasonable for older donors. Age-calibrated mGFR may improve efficiency of the selection process.