Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients.

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant recipients (KT) were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country. This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT.

Pathophysiology of bone disease in chronic kidney disease: from basics to renal osteodystrophy and osteoporosis.

Chronic kidney disease (CKD) is a highly prevalent disease that has become a public health problem. Progression of CKD is associated with serious complications, including the systemic CKD-mineral and bone disorder (CKD-MBD). Laboratory, bone and vascular abnormalities define this condition, and all have been independently related to cardiovascular disease and high mortality rates. The "old" cross-talk between kidney and bone (classically known as "renal osteodystrophies") has been recently expanded to the cardiovascular system, emphasizing the importance of the bone component of CKD-MBD. Moreover, a recently recognized higher susceptibility of patients with CKD to falls and bone fractures led to important paradigm changes in the new CKD-MBD guidelines. Evaluation of bone mineral density and the diagnosis of "osteoporosis" emerges in nephrology as a new possibility "if results will impact clinical decisions". Obviously, it is still reasonable to perform a bone biopsy if knowledge of the type of renal osteodystrophy will be clinically useful (low versus high turnover-bone disease). However, it is now considered that the inability to perform a bone biopsy may not justify withholding antiresorptive therapies to patients with high risk of fracture. This view adds to the effects of parathyroid hormone in CKD patients and the classical treatment of secondary hyperparathyroidism. The availability of new antiosteoporotic treatments bring the opportunity to come back to the basics, and the knowledge of new pathophysiological pathways [OPG/RANKL (LGR4); Wnt-ß-catenin pathway], also affected in CKD, offers great opportunities to further unravel the complex physiopathology of CKD-MBD and to improve outcomes.

[Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients.] / Actualización de las recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (COVID-19) en pacientes con trasplante renal.

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant recipients (KT) were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country.This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT.

Bioavailability of once-daily tacrolimus formulations used in clinical practice in the management of De Novo kidney transplant recipients: the better study.

Multicenter, prospective, observational study to compare the relative bioavailability of once-daily tacrolimus formulations in de novo kidney transplant recipients. De novo kidney transplant recipients who started a tacrolimus-based regimen were included 14 days post-transplant and followed up for 6 months. Data from 218 participants were evaluated: 129 in the LCPT group (Envarsus) and 89 in the PR-Tac (Advagraf) group. Patients in the LCPT group exhibited higher relative bioavailability (Cmin /total daily dose [TDD]) vs. PR-Tac (61% increase; P < .001) with similar Cmin and 30% lower TDD levels (P < .0001). The incidence of treatment failure was 3.9% in the LCPT group and 9.0% in the PR-Tac group (P = .117). Study discontinuation rates were 6.2% in the LCPT group and 12.4% in the PR-Tac group (P = .113). Adverse events, renal function and other complications were comparable between groups. The median accumulated dose of tacrolimus in the LCPT group from day 14 to month 6 was 889 mg. Compared to PR-Tac, LCPT showed higher relative bioavailability, similar effectiveness at preventing allograft rejection, comparable effect on renal function, safety, adherence, treatment failure and premature discontinuation rates.

Protocol for Optimizing the Use of Kidneys From Donors With Seropositivity for Hepatitis C Virus in Seronegative Recipients.

BACKGROUND: The rapid identification of the viral load from hepatitis C virus (HCV) in seropositive donors enables the determination of their infection capacity and the subsequent design of a strategy to optimize the use of direct-action antivirals (DAA) in seronegative recipients. In 2017, we designed an optimization protocol; this study aims to assess its efficacy and safety. METHODS: This is a prospective, multicenter observational study that complies with the Declarations of Helsinki and Istanbul. Donors were HCV seropositive. The HCV and human immunodeficiency virus loads were immediately determined in the donors. For viremic donors, recipients were treated with DAA for 8 weeks. For nonviremic donors, DAA was started if a viral load was detected during the follow-up period. The minimum follow-up period was 6 months posttransplant. RESULTS: This study recruited 28 donors. Just over half of the donors (n = 15; 53.5%) had a nonactive history of injection drug use. Eight (22.4%) donors were viremic, and 20 (87.6%) were nonviremic; 13 (65%) had been treated previously. Nine grafts were ineligible for the protocol. We performed a total of 47 transplants. Procedure I (viremic donors) was performed in 13 recipients (27.7%). Posttransplant viremia was observed in 6 participants. Posttransplant viremia was low (<100 IU/mL) in 4 participants but high (36,000 and 138,000 IU/mL) in 2 participants who had initiated DAA after the transplant; all these patients had a sustained viral response. Seroconversion was observed in 11 of 13 (84.6%) patients. Procedure II (nonviremic donors) was undertaken in 34 (82.3%) patients. No positive viral loads were observed. Seroconversion occurred in 7 of 34 (20.5%) recipients. All recipients maintained kidney function at 6 months posttransplant, except 1 patient with a graft that had never been functional and another patient who died of pancreatitis. Both patients had received kidneys from nonviremic donors. CONCLUSIONS: Our experience supports the efficacy and safety of this protocol.

Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal / Recommendations on management of the SARS-CoV-2 coronavirus pandemic (Covid-19) in kidney transplant patients

La pandemia por coronavirus SARS-CoV-2 (Covid-19) está evolucionando de manera muy rápida y representa un riesgo especial en pacientes inmunodeprimidos y con comorbilidades añadidas. El conocimiento sobre esta infección emergente va también en aumento, si bien, aún sigue habiendo muchas incógnitas, sobre todo en la población con trasplante renal. Este manuscrito presenta una propuesta de actuación con recomendaciones generales y específicas para proteger y prevenir de la infección a esta población tan vulnerable como son los receptores de un trasplante renal

The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients

[Recommendations on management of the SARS-CoV-2 coronavirus pandemic (Covid-19) in kidney transplant patients]. / Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal.

The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients.

Cellular Immunity to Predict the Risk of Cytomegalovirus Infection in Kidney Transplantation: A Prospective, Interventional, Multicenter Clinical Trial.

BACKGROUND: Improving cytomegalovirus (CMV) immune-risk stratification in kidney transplantation is highly needed to establish guided preventive strategies. METHODS: This prospective, interventional, multicenter clinical trial assessed the value of monitoring pretransplant CMV-specific cell-mediated immunity (CMI) using an interferon-γ release assay to predict CMV infection in kidney transplantation. One hundred sixty donor/recipient CMV-seropositive (D+/R+) patients, stratified by their baseline CMV (immediate-early protein 1)-specific CMI risk, were randomized to receive either preemptive or 3-month antiviral prophylaxis. Also, 15-day posttransplant CMI risk stratification and CMI specific to the 65 kDa phosphoprotein (pp65) CMV antigen were investigated. Immunosuppression consisted of basiliximab, tacrolimus, mycophenolate mofetil, and corticosteroids in 80% of patients, whereas 20% received thymoglobulin induction therapy. RESULTS: Patients at high risk for CMV based on pretransplant CMI developed significantly higher CMV infection rates than those deemed to be at low risk with both preemptive (73.3% vs 44.4%; odds ratio [OR], 3.44 [95% confidence interval {CI}, 1.30-9.08]) and prophylaxis (33.3% vs 4.1%; OR, 11.75 [95% CI, 2.31-59.71]) approaches. The predictive capacity for CMV-specific CMI was only found in basiliximab-treated patients for both preemptive and prophylaxis therapy. Fifteen-day CMI risk stratification better predicted CMV infection (81.3% vs 9.1%; OR, 43.33 [95% CI, 7.89-237.96]). CONCLUSIONS: Pretransplant CMV-specific CMI identifies D+/R+ kidney recipients at high risk of developing CMV infection if not receiving T-cell-depleting antibodies. Monitoring CMV-specific CMI soon after transplantation further defines the CMV infection prediction risk. Monitoring CMV-specific CMI may guide decision making regarding the type of CMV preventive strategy in kidney transplantation. CLINICAL TRIALS REGISTRATION: NCT02550639.

Direct-acting Antivirals for the Treatment of Kidney Transplant Patients With Chronic Hepatitis C Virus Infection in Spain: A Long-term Prospective Observational Study.

BACKGROUND: Direct-acting antivirals (DAA) allow effective and safe eradication of hepatitis C virus (HCV) in most patients. There are limited data on the long-term effects of all-oral, interferon-free DAA combination therapies in kidney transplant (KT) patients infected with HCV. Here we evaluated the long-term tolerability, efficacy, and safety of DAA combination therapies in KT patients with chronic HCV infection. METHODS: Clinical data from KT patients treated with DAA were collected before, during, and after the treatment, including viral response, immunosuppression regimens, and kidney and liver function. RESULTS: Patients (N = 226) were mostly male (65.9%) aged 56.1 ± 10.9 years, with a median time from KT to initiation of DAA therapy of 12.7 years and HCV genotype 1b (64.6%). Most patients were treated with sofosbuvir-based therapies. Rapid virological response at 1 month was achieved by 89.4% of the patients and sustained virological response by week 12 by 98.1%. Liver function improved significantly after DAA treatment. Tacrolimus dosage increased 37% from the beginning of treatment (2.5 ± 1.7 mg/d) to 1 year after the start of DAA treatment (3.4 ± 1.9 mg/d, P < 0.001). Median follow-up was 37.0 months (interquartile range, 28.4-41.9) and death-censored graft survival was 91.1%. Adverse events resulting from DAA treatment, especially anemia, were reported for 31.0% of the patients. CONCLUSIONS: Chronic HCV infection can be treated efficiently and safely with DAA therapy in KT patients. Most patients retained stable kidney function and improved liver function. Tacrolimus dose had to be increased in most patients, potentially as a result of better liver function.

Apolipoprotein A-Ib as a biomarker of focal segmental glomerulosclerosis recurrence after kidney transplantation: diagnostic performance and assessment of its prognostic value - a multi-centre cohort study.

Recurrence of idiopathic focal segmental glomerulosclerosis (FSGS) is a serious complication after kidney transplantation. FSGS relapse is suspected by a sudden increase in proteinuria but there is not an accurate noninvasive diagnostic tool to confirm this entity or to detect patients at risk. We aimed to validate the diagnostic performance of ApoA-Ib to detect FSGS relapses by measuring urinary ApoA-Ib in a retrospective cohort of 61 kidney transplanted patients (37 FSGS and 24 non-FSGS). In addition, to assess the ApoA-Ib predictive ability, ApoA-Ib was measured periodically in a prospective cohort of 13 idiopathic FSGS patients who were followed during 1 year after transplantation. ApoA-Ib had a sensitivity of 93.3% and a specificity of 90.9% to diagnose FSGS relapses, with a high negative predictive value (95.2%), confirming our previous results. In the prospective cohort, ApoA-Ib predated the recurrence in four of five episodes observed. In the nonrelapsing group (n = 9), ApoA-Ib was negative in 37 of 38 samples. ApoA-Ib has the potential to be a good diagnostic biomarker of FSGS relapses, providing a confident criterion to exclude false positives even in the presence of high proteinuria. It has also the potential to detect patients at risk of relapse, even before transplantation.

Medium-Term Renal Function in a Large Cohort of Stable Kidney Transplant Recipients Converted From Twice-Daily to Once-Daily Tacrolimus.

BACKGROUND: There is some evidence pointing toward better renal function in kidney transplant recipients (KTR) treated with once-daily tacrolimus (QD-TAC) vs. twice-daily tacrolimus (BID-TAC). METHODS: This is an extension study of a 1-year, single arm prospective study of stable KTR who were converted from BID-TAC to QD-TAC (4.9 ± 4.0 years after transplantation) in Spanish routine clinical practice. Patient and graft survival, renal function, acute rejection episodes, and other analytic parameters were assessed at 24 and 36 months after conversion. RESULTS: A total of 1798 KTR were included in the extension study. Tacrolimus doses at 36 months were significantly lower compared to those at time of conversion (-0.2 mg/day; P = 0.023). Blood levels were lower than baseline during all the study (P < 0.001). Graft and patient survival at 3 years after conversion were 93.9% and 95.1%, respectively. Compared with baseline, the mean estimated glomerular filtration rate (eGFR) remained very stable at all timepoints (56.7 ± 19.8 vs 58.1 ± 24.6 mL/min per 1.73 m(2) at month 36; P = 0.623). Even when patients reinitiating dialysis were counted as eGFR = 0, the mean eGFR was very stable. In fact, a small but significant increase was observed at 36 months versus baseline (+0.1 mL/min per 1.73 m(2); P = 0.025). An increase in proteinuria was observed at 36 months versus baseline (+0.11 g/24 h; P < 0.001). Acute rejection rates were low during the study. CONCLUSIONS: Conversion from BID-TAC to QD-TAC in a large cohort of stable KTR was safe and associated with a very stable renal function after 3 years. Comparative studies are warranted to assess the feasibility of such conversion.

High incidence of delayed graft function in HIV-infected kidney transplant recipients.

Kidney transplantation (KT) outcomes in human immunodeficiency virus (HIV)-infected recipients are under continuous research. High incidence of early post-transplant complications such as acute rejection has been observed. A multicenter study including HIV-infected patients who underwent KT in Spain, from 2001 to 2011, was performed. The study population included 108 recipients, 36 HIV-infected, and 72 matched HIV-negative KT recipients. HIV-infected recipients developed more delayed graft function (DGF) (52% vs. 21%, P < 0.001). One- and 3-year graft survival was 91.6% and 86.2% in HIV-infected patients, and 97.1% and 94.7% in HIV-negative patients (P = 0.052). In two-variate Cox analysis, HIV infection was not a predictor of graft loss after adjusting for time on dialysis, acute rejection, and DGF. Multivariate analysis for DGF revealed HIV-positive status as independent risk factor. We analyzed the evolution of immunosuppressive and antiretroviral therapy (ART). In HIV-infected patients tacrolimus trough levels were very high in the first week and significantly lower in the second week post-transplant (P = 0.042). Post-transplant ART was significantly changed: protease inhibitors use decreased (P = 0.034) and integrase inhibitor use increased (P < 0.001). DGF is another frequent early complication in HIV-infected recipients that can affect graft survival. Strategies to prevent DGF and antiretroviral regimes with less drug interactions could improve outcomes.

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.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in renal transplantation between 1990 and 2002 in Spain.

Background. Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II type 1 receptor blockers (ARB) decrease cardiovascular mortality and slow the progression of renal disease in non-transplant patients, but their impact on kidney transplant outcome has not been well established.Methods. Patients receiving a renal allograft in Spain in 1990, 1994, 1998 and 2002 were considered for the present study. Only adult (>/=18 years) recipients of a single kidney transplant functioning at the end of the first year were considered. A total of 4842 patients with clinical data about ACEI/ARB therapy were included.Results. During the initial 2 years after transplant, ACEI/ARB were less frequently used in the 1990 and 1994 cohorts than in 1998 and 2002 (15.1%, 24.6%, 33.5% and 45.1%, respectively; P < 0.001). During the first year, a total of 1063 patients (22.8%) received ACEI/ARB treatment, and graft survival (50.0% for treated patients and 51.4% for untreated, P = ns), death-censored graft survival (60.6% versus 63.5%, P = ns) and patient survival (68.8% versus 66.6%, P = ns) were not different. During the initial 2 years, 1472 patients (31.4%) received treatment with ACEI/ARB, and graft survival tended to be higher in treated patients (54.4% and 50.9%, P = 0.063). Since there was an interaction between ACEI/ARB treatment and year of transplant, graft survival was analysed in each cohort. Cox regression analysis including the propensity score for ACEI/ARB treatment showed an association between ACEI/ARB treatment and graft survival in the 2002 cohort (relative risk 0.36 and 95% confidence interval 0.17-0.75, P = 0.007). Death-censored graft survival (63.8% versus 63.1%, P = ns) and patient survival (68.1% and 66.5%, P = ns) were not significantly different.Conclusions. The use of ACEI/ARB during the initial 2 years after transplantation was associated with a better graft survival, but this effect was only observed in the 2002 cohort.

Improved renal function, with similar proteinuria, after two years of early tacrolimus withdrawal from a regimen of sirolimus plus tacrolimus.

Results at 1 year of a pilot randomized trial with 87 kidney graft recipients, comparing the maintenance treatment with sirolimus, tacrolimus and steroids (group I) versus tacrolimus withdrawal since the third month onward, followed by maintenance with SRL and steroids (group II) have shown that early elimination of tacrolimus may result in improved renal function and blood pressure control. At 2 years, 26 and 25 patients in groups I and II, respectively, were analyzed in an on-therapy and an ITT analysis. In the on-therapy analysis, group II showed lower serum creatinine (1.3+/-0.2 vs. 1.6+/-0.6 mg/dL) and lower diastolic blood pressure (74+/-9 vs. 80+/-11 mm Hg). No acute rejections occurred during the second year of follow-up. In more than 90% of patients, proteinuria was less than 1 g/d, and in 50% it was negative. In the ITT analysis, differences were found only in diastolic blood pressure (80+/-10 vs. 74+/-8 mm Hg in groups I and II respectively, P=0.009). Tacrolimus withdrawal from a combination of sirolimus and tacrolimus, in selected patients, may be observed at 2 years by an improvement in renal function and blood pressure without a higher incidence of proteinuria.

Pilot randomized study of early tacrolimus withdrawal from a regimen with sirolimus plus tacrolimus in kidney transplantation.

We performed a randomized trial to compare two regimens of low-risk kidney allograft recipients in the first year after transplantation. Both regimens initially included sirolimus, tacrolimus and steroids; one with long-term maintenance with these drugs vs. tacrolimus withdrawal. Group I: sirolimus levels of 4-8 ng/mL, plus tacrolimus 8-12 ng/mL for 3 months, and 5-10 ng/mL after month 3. Group II: sirolimus concentration of 8-16 ng/mL, plus tacrolimus 3-8 ng/mL with tacrolimus elimination from month 3 onwards. Owing to difficulties in achieving target levels, the protocol was amended to increase the doses. Eighty-seven patients were recruited. In the intention-to-treat analysis, glomerular filtration rate (GFR) at 12 months, adjusted to zero for graft loss, was similar in both groups (58.8 and 59.9 mL/min). Analysis of patients remaining on protocol showed that GFR was higher in group II only in the patients postamendment (58.4 and 72.9 mL/min, p = 0.03). Rates of biopsy-confirmed rejection (BCAR) were 9.3% and 22.7% in groups I and II, respectively (p = NS). After amendment, BCAR rates were 10.3% and 11.1% (p = NS). Diastolic blood pressure was significantly lower in patients who eliminated tacrolimus (80.4 vs. 75.6 mmHg) (p = 0.03). Combining sirolimus and tacrolimus with adequate loading doses was associated with a low incidence of BCAR, and allowed tacrolimus elimination in a high proportion of patients, which may be followed by amelioration in renal function and blood pressure.

Epidemiology of arterial hypertension in renal transplant patients: changes over the last decade.

BACKGROUND: Arterial hypertension is a common clinical problem in renal transplantation, with important consequences on graft and patient survival. PATIENTS AND METHODS: A total of 3365 adult patients transplanted in 1990 (N = 824), 1994 (N = 1075) and 1998 (N = 1466) with a functioning graft after the first year were included. In this study, arterial hypertension was defined as systolic blood pressure (SBP) > or =140 mmHg and/or diastolic blood pressure (DBP) > or =90 mmHg and/or treatment with antihypertensive drugs. The use of angiotensin converting enzyme (ACE) inhibitors or angiotensin II (ATII) receptor blockers during the first year was recorded. RESULTS: The prevalence of hypertension showed a progressive and significant increase during follow-up after renal transplantation in the three periods analysed, although SBP and DBP were lower in patients who underwent transplantation in 1998. The presence of arterial hypertension at 1 year was significantly associated with recipient gender (male), donor age (< 60 years), immunosuppressive therapy (cyclosporine), serum creatinine and year of transplantation. Arterial hypertension was not associated with graft survival and cardiovascular mortality. The prevalence and severity of hypertension was significantly lower in patients treated with tacrolimus vs cyclosporine. The use of ACE inhibitors or ATII receptor blockers has increased in the recent years. CONCLUSIONS: Arterial hypertension remained a common problem in renal transplantation, although in recent years the intensity of the control seems satisfactory. The use of ACE inhibitors or ATII receptor blockers has increased significantly in the last years.