Molecular bases for the association of FHR-1 with atypical hemolytic uremic syndrome and other diseases.

Factor H (FH)-related proteins are a group of partly characterized complement proteins thought to promote complement activation by competing with FH in binding to surface-bound C3b. Among them, FH-related protein 1 (FHR-1) is remarkable because of its association with atypical hemolytic uremic syndrome (aHUS) and other important diseases. Using a combination of biochemical, immunological, nuclear magnetic resonance, and computational approaches, we characterized a series of FHR-1 mutants (including 2 associated with aHUS) and unraveled the molecular bases of the so-called deregulation activity of FHR-1. In contrast with FH, FHR-1 lacks the capacity to bind sialic acids, which prevents C3b-binding competition between FH and FHR-1 in host-cell surfaces. aHUS-associated FHR-1 mutants are pathogenic because they have acquired the capacity to bind sialic acids, which increases FHR-1 avidity for surface-bound C3-activated fragments and results in C3b-binding competition with FH. FHR-1 binds to native C3, in addition to C3b, iC3b, and C3dg. This unexpected finding suggests that the mechanism by which surface-bound FHR-1 promotes complement activation is the attraction of native C3 to the cell surface. Although C3b-binding competition with FH is limited to aHUS-associated mutants, all surface-bound FHR-1 promotes complement activation, which is delimited by the FHR-1/FH activity ratio. Our data indicate that FHR-1 deregulation activity is important to sustain complement activation and C3 deposition at complement-activating surfaces. They also support that abnormally elevated FHR-1/FH activity ratios would perpetuate pathological complement dysregulation at complement-activating surfaces, which may explain the association of FHR-1 quantitative variations with diseases.

Eculizumab Modifies Outcomes in Adults with Atypical Hemolytic Uremic Syndrome with Acute Kidney Injury.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare disease associated with congenital or acquired genetic abnormalities that result in uncontrolled complement activation, leading to thrombotic microangiopathy and kidney failure. Until recently, the only treatment was plasma exchange or plasma infusion (PE/PI), but 60% of patients died or had permanent kidney damage despite treatment. Eculizumab, a complement inhibitor, has shown promising results in aHUS. However, data are mainly extracted from case reports or studies of heterogeneous cohorts, and no direct comparison with PE/PI is available. METHODS: An observational retrospective study of adult, dialysis-dependent aHUS patients with acute kidney injury (AKI) who were treated with either PE/PI alone or with second-line eculizumab in our center. We compared the effect of PE/PI and eculizumab on kidney function, hypertension, proteinuria, hematologic values, relapse, and death. RESULTS: Thirty-one patients were included (females, 18; sporadic aHUS, 29; mean age, 46 ± 20 years). Twenty-six patients were treated with PE/PI alone, and 5 were deemed to be plasma-resistant and received eculizumab after stopping PE/PI. Among patients receiving eculizumab, 80% attained complete recovery of kidney function, 100% stopped dialysis, 20% had decreased proteinuria, and no patient relapsed (vs. 38.5, 50, 15.4, and 11.5%, respectively, of patients receiving only PE/PI). At 1-year of follow-up, no deaths had occurred in either group. CONCLUSION: Eculizumab shows greater efficacy than PE/PI alone for the treatment of adult aHUS patients with AKI. Prospective studies and meta-analyses are warranted to confirm our findings and set guidelines for treatment, monitoring, and maintenance.

Improving the Access of Highly Sensitized Patients to Kidney Transplantation From Deceased Donors: The Spanish PATHI Program With Allocation Based on the Virtual Crossmatch.

BACKGROUND: In 2015, the Spanish National Transplant Organization developed a prioritization system (Program for Access to Transplantation for Highly Sensitized Patients [PATHI]) to increase transplant options for patients with calculated panel-reactive antibodies (cPRAs) ≥98%, based on virtual crossmatch. We describe the experience with the implementation of PATHI and assess its efficacy. METHODS: PATHI registry was used to collect characteristics of donors and patients between June 15, 2015, and March 1, 2018. One-year graft and patient survival and acute rejection were also measured. A Cox model was used to identify factors related to patient death and graft loss and logistical regression for those associated with rejection. RESULTS: One thousand eighty-nine patients were included, and 272 (25%) were transplanted. Transplant rate by cPRA was 54.9%, 40.5%, and 12.8% in patients with cPRA98%, cPRA99%, and cPRA100%, respectively. One-year patient survival was 92.5%. Recipient age ≥60, time under dialysis >7 y, and delayed graft function were mortality risk factors. One-year graft survival was 88.7%. The factor related to graft loss was delayed graft function. The rejection rate was 22%. Factors related to rejection were sex, older recipients, and posttransplant donor-specific antibodies. CONCLUSIONS: A prioritization approach increases transplant options for highly sensitized patients with appropriate short-term postransplant outcomes. Along with other programs, PATHI may inspire other countries to adopt strategies to meet transplant needs of these patients.

Enteric-coated mycophenolate sodium in de novo and maintenance kidney-pancreas transplant recipients.

BACKGROUND: Our objective was to describe efficacy and safety of enteric-coated mycophenolate sodium (EC-MPS) in de novo and maintenance recipients of kidney-pancreas transplant in the clinical practice. METHODS: Observational, multicentre, prospective, 12-month study. RESULTS: We included 24 de novo and 24 maintenance patients. EC-MPS mean (± SD) doses at initiation in de novo patients were 1440 ± 0 vs. 1268 ± 263 mg/d at month 12 (M12). Patient and renal graft survival at one yr were 100%, and pancreatic graft survival was 83.3% (two losses owing to technical failure and two owing to rejection). In the maintenance cohort, EC-MPS was introduced at a median (P25-P75) of 30 (6-71) months after transplant. Baseline doses were 585 ± 310 vs. 704 ± 243 mg/d at M12. In this group, a significant increase in creatinine clearance was observed (65 ± 22 at baseline vs. 74 ± 20 mL/min at M12, p = 0.011). Patient, renal, and pancreatic graft survival were 100%, 95.8%, and 100%, respectively (one kidney graft loss owing to rejection). During follow-up, one patient from each group discontinued EC-MPS. CONCLUSIONS: The efficacy of EC-MPS in the clinical practice of kidney-pancreas transplantation is good, with high patient and grafts survival at 12 months, and good safety profile. The maintenance group displayed an improvement in renal function.

Treatment with sotrovimab for SARS-CoV-2 infection in a cohort of high-risk kidney transplant recipients.

Background: Sotrovimab is a neutralizing monoclonal antibody (mAb) that seems to remain active against recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. The evidence on its use in kidney transplant (KT) recipients, however, is limited. Methods: We performed a multicenter, retrospective cohort study of 82 KT patients with SARS-CoV-2 infection {coronavirus disease 2019 [COVID-19]} treated with sotrovimab. Results: Median age was 63 years. Diabetes was present in 43.9% of patients, and obesity in 32.9% of patients; 48.8% of patients had an estimated glomerular filtration rate under 30 mL/minute/1.73 m2. Additional anti-COVID-19 therapies were administered to 56 patients, especially intravenous steroids (65.9%). Sotrovimab was administered early (<5 days from the onset of the symptoms) in 46 patients (56%). Early-treated patients showed less likely progression to severe COVID-19 than those treated later, represented as a lower need for ventilator support (2.2% vs 36.1%; P < .001) or intensive care admission (2.2% vs 25%; P = .002) and COVID-19-related mortality (2.2% vs 16.7%; P = .020). In the multivariable analysis, controlling for baseline risk factors to severe COVID-19 in KT recipients, early use of sotrovimab remained as a protective factor for a composite outcome, including need for ventilator support, intensive care, and COVID-19-related mortality. No anaphylactic reactions, acute rejection episodes, impaired kidney function events, or non-kidney side effects related to sotrovimab were observed. Conclusions: Sotrovimab had an excellent safety profile, even in high-comorbidity patients and advanced chronic kidney disease stages. Earlier administration could prevent progression to severe disease, while clinical outcomes were poor in patients treated later. Larger controlled studies enrolling KT recipients are warranted to elucidate the true efficacy of monoclonal antibody therapies.

Recommendations for living donor kidney transplantation.

This Guide for Living Donor Kidney Transplantation (LDKT) has been prepared with the sponsorship of the Spanish Society of Nephrology (SEN), the Spanish Transplant Society (SET), and the Spanish National Transplant Organization (ONT). It updates evidence to offer the best chronic renal failure treatment when a potential living donor is available. The core aim of this Guide is to supply clinicians who evaluate living donors and transplant recipients with the best decision-making tools, to optimise their outcomes. Moreover, the role of living donors in the current KT context should recover the level of importance it had until recently. To this end the new forms of incompatible HLA and/or ABO donation, as well as the paired donation which is possible in several hospitals with experience in LDKT, offer additional ways to treat renal patients with an incompatible donor. Good results in terms of patient and graft survival have expanded the range of circumstances under which living renal donors are accepted. Older donors are now accepted, as are others with factors that affect the decision, such as a borderline clinical history or alterations, which when evaluated may lead to an additional number of transplantations. This Guide does not forget that LDKT may lead to risk for the donor. Pre-donation evaluation has to centre on the problems which may arise over the short or long-term, and these have to be described to the potential donor so that they are able take them into account. Experience over recent years has led to progress in risk analysis, to protect donors' health. This aspect always has to be taken into account by LDKT programmes when evaluating potential donors. Finally, this Guide has been designed to aid decision-making, with recommendations and suggestions when uncertainties arise in pre-donation studies. Its overarching aim is to ensure that informed consent is based on high quality studies and information supplied to donors and recipients, offering the strongest possible guarantees.

HIV infection and renal transplantation.

BACKGROUND: Some aspects of kidney transplant outcome in human immunodeficiency virus (HIV)-infected patients are still controversial. Besides, published experience is scarce in Europe. METHODS: A multicentre case-control study was designed to analyse the outcome of renal transplant in HIV + patients in Spain. Twenty HIV + patients were compared with a matched cohort of 40 HIV - recipients. RESULTS: Post-transplant follow-up period was 39.98 ± 36.51 months. Pre-transplant dialysis duration and the incidence of pre-transplant opportunistic infections were significantly higher for HIV + patients. Following transplantation, HIV + recipients presented lower incidence of immediate renal function and more acute rejection. Graft survival was lower although the difference was not significant (1 year: 85 vs 97.5%; 5 years: 74.4 vs 91%; log-rank P = 0.058). There was no difference in patient survival rates. Eight patients in each group presented hepatitis C (HCV) infection. Coinfected patients were compared with HIV +/HCV - and HIV -/HCV + recipients. Coinfected patients presented more time on dialysis, greater duration of delayed graft function and lower graft survival (HIV +/HCV + vs HIV +/HCV -: log-rank P = 0.009; HIV +/HCV + vs HIV -/HCV +: log-rank P = 0.02). Conversely, when excluding HCV + patients in both groups, graft survival in HIV + and HIV - patients was similar. CONCLUSIONS: The outcome was good, particularly in non-coinfected patients. Coinfected patients constitute an especially high-risk group for kidney transplantation.

[Psychometric properties of the Spanish version of the Revised Competitive State Anxiety Inventory-2 with athletes]. / Propiedades psicométricas de la versión española del Inventariode Ansiedad Competitiva CSAI-2R en deportistas.

The aim of this work was to develop a Spanish adaptation of the Revised Competitive State Anxiety Inventory-2. The scale was translated and its psychometric properties were analyzed with data from a sample of 149 athletes. Exploratory and confirmatory factor analyses were performed which supported a 16-item CSAI-2R assessing the three hypothesised dimensions of anxiety: Somatic anxiety, Cognitive anxiety, and Self-confidence. Overall fit of the model was good with a value of .97 for Comparative and Non-Normed Fit Indexes, and .045 for Root Mean Square Error of Approximation. Cronbach alpha coefficients for the factors ranged from .79 to .83. It is concluded that this version shows adequate properties, in terms of its dimensionality and internal consistency. Guidelines are also provided for future research on its validity as a measure of state anxiety in competitive situations.

Kidney transplantation from HLA-incompatible live donors: Efficiency and outcome of 32 patients after desensitisation. / Trasplante renal procedente de donante vivo HLA incompatible: Eficacia y pronóstico en 32 pacientes tras desensibilización.

Desensitisation is a procedure undergone by the recipient of a kidney transplant from a donor who is cross-match positive. The aim of this study was to present the outcomes from our hospital of kidney transplant recipients from HLA-incompatible live donors after desensitisation. We studied 32 patients aged 46±14 years with a mean fluorescence intensity (MFI) versus class I HLA of 7979±4089 and 6825±4182 MFI versus class II and relative intensity scale (RIS) of 8.9±7.6. The complement-dependent cytotoxicity (CDC) cross-matching test was positive in 18 patients, flow cytometry was positive in 7 patients and donor-specific antibodies (DEA) were detected in 7. The protocol used was rituximab, plasmapheresis/immunoadsorption, immunoglobulins, tacrolimus, mycophenolic acid derivatives and prednisone. After 8±3 sessions of plasmapheresis/immunoadsorption, 23 patients were trasplanted (71.9%) and desensitisation was ineffective in 9. There were baseline differences in MFI class I (P<.001), RIS (P=.008), and CDC cross-matching, DSA and flow cytometry (P=.05). MFI class I and RIS were predictors of inefficiency in ROC curves. After follow-up of 43±30 months, 13 patients (56%) presented postoperative bleeding, 3 (13%) delayed graft function, 4 (17.4%) acute rejection, 6 (26%) CMV viraemia and 1 (4%) BK viraemia. Five-year patient survival was 90%, with 86% allograft survival. Five-year creatinine was 1.5±0.4 and proteinuria was 0.5±0.7. CONCLUSIONS: Kidney transplantation from HLA-incompatible live donors after desensitisation was possible in 71.9% of patients. MFI class I and RIS predict the inefficiency of desensitisation. Five-year allograft survival (86%) was acceptable with a low incidence of acute rejection (17.4%), although with a greater trend towards postoperative bleeding.

Mineral metabolism disorders, vertebral fractures and aortic calcifications in stable kidney transplant recipients: The role of gender (EMITRAL study).

BACKGROUND AND OBJECTIVES: The relationship between mineral metabolism disorders, bone fractures and vascular calcifications in kidney transplant recipients has not been established. METHOD: We performed a cross-sectional study in 727 stable recipients from 28 Spanish transplant clinics. Mineral metabolism parameters, the semi-quantification of vertebral fractures and abdominal aortic calcifications were determined centrally. RESULTS: Vitamin D deficiency (25OHD3<15ng/ml) was more common in female recipients at CKD-T stages I-III (29.6% vs 44.4%; p=0.003). The inverse and significant correlation between 25OHD3 and PTH was gender-specific and women exhibited a steeper slope than men (p=0.01). Vertebral fractures (VFx) with deformity grade ≥2 were observed in 15% of recipients. Factors related to VFx differed by gender; in males, age (OR 1.04; 95% CI 1.01-1.06) and CsA treatment (OR: 3.2; 95% CI: 1.6-6.3); in females, age (OR 1.07; 95% CI: 1.03-1.12) and PTH levels (OR per 100pg/ml increase: 1.27; 95% CI: 1.043-1.542). Abdominal aortic calcifications were common (67.2%) and related to classical risk factors but not to mineral metabolism parameters. CONCLUSIONS: Vitamin D deficiency is more common among female kidney transplant recipients at earlier CKD-T stages, and it contributes to secondary hyperparathyroidism. Prevalent vertebral fractures are only related to high serum PTH levels in female recipients.