Treatment of early borderline lesions in low immunological risk kidney transplant patients: a Spanish multicenter, randomized, controlled parallel-group study protocol: the TRAINING study.

BACKGROUND: Subclinical inflammation, including borderline lesions (BL), is very common (30-40%) after kidney transplantation (KT), even in low immunological risk patients, and can lead to interstitial fibrosis/tubular atrophy (IFTA) and worsening of renal function with graft loss. Few controlled studies have analyzed the therapeutic benefit of treating these BL on renal function and graft histology. Furthermore, these studies have only used bolus steroids, which may be insufficient to slow the progression of these lesions. Klotho, a transmembrane protein produced mainly in the kidney with antifibrotic properties, plays a crucial role in the senescence-inflammation binomial of kidney tissue. Systemic and local inflammation decrease renal tissue expression and soluble levels of α-klotho. It is therefore important to determine whether treatment of BL prevents a decrease in α-klotho levels, progression of IFTA, and loss of kidney function. METHODS: The TRAINING study will randomize 80 patients with low immunological risk who will receive their first KT. The aim of the study is to determine whether the treatment of early BL (3rd month post-KT) with polyclonal rabbit antithymocyte globulin (Grafalon®) (6 mg/kg/day) prevents or decreases the progression of IFTA and the worsening of graft function compared to conventional therapy after two years post-KT, as well as to analyze whether treatment of BL with Grafalon® can modify the expression and levels of klotho, as well as the pro-inflammatory cytokines that regulate its expression. DISCUSSION: This phase IV investigator-driven, randomized, placebo-controlled clinical trial will examine the efficacy and safety of Grafalon® treatment in low-immunological-risk KT patients with early BL. TRIAL REGISTRATION: clinicaltrials.gov : NCT04936282. Registered June 23, 2021, https://clinicaltrials.gov/ct2/show/NCT04936282?term=NCT04936282&draw=2&rank=1 . Protocol Version 2 of 21 January 2022. SPONSOR: Canary Isles Institute for Health Research Foundation, Canary Isles (FIISC). mgomez@fciisc.org .

Decrease in CD14++CD16+ Monocytes in Low-Immunological-Risk Kidney Transplant Patients with Subclinical Borderline Inflammation.

We determined the association between CD14++CD16+ monocytes and subclinical infiltrates that do not reach the histological threshold for rejection (≥Banff IA). We studied low-immunological-risk kidney-transplant recipients in a clinical trial (NCT02284464; EudraCT 2012-003298-24) whose protocol biopsy in the third month showed no significant changes or borderline lesions (BL). Flow cytometry was used to analyze the percentage of CD14++CD16+ monocytes in peripheral blood (PB) and blood from a fine-needle-aspiration biopsy (FNAB). A protocol biopsy was performed in 81 low-immunological-risk patients, of whom 15 were excluded (BK polyomavirus and rejection). The 28 (42.4%) with borderline lesions had significantly low levels of CD14++CD16+ in PB compared to patients with normal biopsies (7.9 ± 5.4 vs. 13.0 ± 12.8; p = 0.047). Patients without significant changes had similar percentages of CD14++CD16+ monocytes in the graft blood (GB) and FNAB blood. The percentage of these monocytes in the patients with an interstitial infiltrate, however, increased significantly in the FNAB blood compared to the GB: 16.9 ± 16.6 vs. 7.9 ± 5.4; p = 0.006. A difference of 50% in CD14++CD16+ in the GB versus the PB was a significant risk factor (p = 0.002) for BL, increasing the risk seven times. A decrease in CD14++CD16+ in the PB could be associated with the recruitment of these cells to the graft tissue in cases of subclinical BL inflammatory infiltrates below the threshold for rejection.

Clinical Relevance of Corticosteroid Withdrawal on Graft Histological Lesions in Low-Immunological-Risk Kidney Transplant Patients.

The impact of corticosteroid withdrawal on medium-term graft histological changes in kidney transplant (KT) recipients under standard immunosuppression is uncertain. As part of an open-label, multicenter, prospective, phase IV, 24-month clinical trial (ClinicalTrials.gov, NCT02284464) in low-immunological-risk KT recipients, 105 patients were randomized, after a protocol-biopsy at 3 months, to corticosteroid continuation (CSC, n = 52) or corticosteroid withdrawal (CSW, n = 53). Both groups received tacrolimus and MMF and had another protocol-biopsy at 24 months. The acute rejection rate, including subclinical inflammation (SCI), was comparable between groups (21.2 vs. 24.5%). No patients developed dnDSA. Inflammatory and chronicity scores increased from 3 to 24 months in patients with, at baseline, no inflammation (NI) or SCI, regardless of treatment. CSW patients with SCI at 3 months had a significantly increased chronicity score at 24 months. HbA1c levels were lower in CSW patients (6.4 ± 1.2 vs. 5.7 ± 0.6%; p = 0.013) at 24 months, as was systolic blood pressure (134.2 ± 14.9 vs. 125.7 ± 15.3 mmHg; p = 0.016). Allograft function was comparable between groups and no patients died or lost their graft. An increase in chronicity scores at 2-years post-transplantation was observed in low-immunological-risk KT recipients with initial NI or SCI, but CSW may accelerate chronicity changes, especially in patients with early SCI. This strategy did, however, improve the cardiovascular profiles of patients.

Impact of HLA Mismatching on Early Subclinical Inflammation in Low-Immunological-Risk Kidney Transplant Recipients.

The impact of human leukocyte antigen (HLA)-mismatching on the early appearance of subclinical inflammation (SCI) in low-immunological-risk kidney transplant (KT) recipients is undetermined. We aimed to assess whether HLA-mismatching (A-B-C-DR-DQ) is a risk factor for early SCI. As part of a clinical trial (Clinicaltrials.gov, number NCT02284464), a total of 105 low-immunological-risk KT patients underwent a protocol biopsy on the third month post-KT. As a result, 54 presented SCI, showing a greater number of total HLA-mismatches (p = 0.008) and worse allograft function compared with the no inflammation group (48.5 ± 13.6 vs. 60 ± 23.4 mL/min; p = 0.003). Multiple logistic regression showed that the only risk factor associated with SCI was the total HLA-mismatch score (OR 1.32, 95%CI 1.06-1.64, p = 0.013) or class II HLA mismatching (OR 1.51; 95%CI 1.04-2.19, p = 0.032) after adjusting for confounder variables (recipient age, delayed graft function, transfusion prior KT, and tacrolimus levels). The ROC curve illustrated that the HLA mismatching of six antigens was the optimal value in terms of sensitivity and specificity for predicting the SCI. Finally, a significantly higher proportion of SCI was seen in patients with >6 vs. ≤6 HLA-mismatches (62.3 vs. 37.7%; p = 0.008). HLA compatibility is an independent risk factor associated with early SCI. Thus, transplant physicians should perhaps be more aware of HLA mismatching to reduce these early harmful lesions.

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.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern.

BACKGROUND: Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC. SUMMARY: This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

C3 glomerulonephritis associated with monoclonal gammopathy of renal significance: case report.

BACKGROUND: Morbidity associated with monoclonal gammopathy of renal significance is high due to the severe renal lesions and the associated systemic alterations. Accordingly, early diagnosis is fundamental, as is stopping the clonal production of immunoglobulins using specific chemotherapy. CASE PRESENTATION: A 75-year-old man with chronic renal disease of unknown origin since 2010 experienced rapid worsening of renal function over a period of 6 mos. Bone marrow biopsy showed monoclonal gammopathy of undetermined significance. Kidney biopsy showed the presence of C3 glomerulonephritis, with exclusive deposits of C3 visible on immunofluorescence and a membranoproliferative pattern on light microscopy. Skin biopsy showed endothelial deposition of complement. Given both the renal and cutaneous involvement the patient was considered to have monoclonal gammopathy of renal significance. We considered an underlying pathogenic mechanism for the renal alteration secondary to activation of the alternative complement pathway by the anomalous immunoglobulin. Despite treatment with plasmapheresis, bortezomib and steroids, advanced chronic kidney disease developed. CONCLUSIONS: The possible underlying cause of the monoclonal gammopathy of renal significance suggests that monoclonal gammopathy should be considered in adult patients with membranoproliferative glomerulonephritis.

Mortality in Elderly Waiting-List Patients Versus Age-Matched Kidney Transplant Recipients: Where is the Risk?

The number of elderly patients on the waiting list (WL) for kidney transplantation (KT) has risen significantly in recent years. Because KT offers a better survival than dialysis therapy, even in the elderly, candidates for KT should be selected carefully, particularly in older waitlisted patients. Identification of risk factors for death in WL patients and prediction of both perioperative risk and long-term post-transplant mortality are crucial for the proper allocation of organs and the clinical management of these patients in order to decrease mortality, both while on the WL and after KT. In this review, we examine the clinical results in studies concerning: a) risk factors for mortality in WL patients and KT recipients; 2) the benefits and risks of performing KT in the elderly, comparing survival between patients on the WL and KT recipients; and 3) clinical tools that should be used to assess the perioperative risk of mortality and predict long-term post-transplant survival. The acknowledgment of these concerns could contribute to better management of high-risk patients and prophylactic interventions to prolong survival in this particular population, provided a higher mortality is assumed.

Increase in CD8+CD158a+ T Cells in Kidney Graft Blood is Associated with Better Renal Function.

BACKGROUND Studies of liver and heart transplant patients have shown a gradual reconstruction of the CD8 KIR2D+ T cell subpopulations, measured in peripheral blood (PB), associated with better graft acceptance. The kinetics of these populations in kidney transplants, however, is still poorly understood, especially given the lack of studies of blood samples from the kidney graft. MATERIAL AND METHODS Flow cytometry was used to measure CD8+CD158a/b/e T cells in 69 kidney transplant patients who had stable renal function during follow-up. Measurements were made at 3, 6, and 12 months post-transplantation in graft capillary blood extracted by fine needle aspiration puncture (FNAP) and in PB. RESULTS No progressive increase was found in the PB subpopulations. However, the CD8+CD158a+ subsets increased significantly at 12 months in the graft blood versus the PB samples (3.91±4.59 vs. 2.84±4.71; p=0.021). The ratio of the percentage of CD8+CD158a+ cells in graft blood compared to PB at 12 months was associated with better renal function in those patients with a ratio ≥3 (66.6±14.53 vs. 55.7±21.6; p=0.032). CONCLUSIONS An increased ratio of CD8+CD158a+ cells, measured by flow cytometry, between graft blood and PB was associated with improved renal function.

Decrease in the percentage of peripheral blood CXCR3highCD4+ lymphocytes after renal transplantation.

INTRODUCTION: Previous studies suggest that infiltration into the graft of active T cells following kidney transplantation depends on the expression of chemokines and their interaction with their T-cell receptors. However, little is known about the natural history of the expression of these molecules during the early post-transplantation phase. AIM: To evaluate the percentage of CXCR3highCD4+ and CCR4highCD4+ cells, as markers of the Th1 and Th2 populations, in peripheral blood from uremic patients before transplantation and six months after maintaining an acceptable kidney graft function. MATERIAL AND METHODS: Flow cytometry was used to measure CXCR3highCD4+ and CCR4highCD4+ cells from 44 consecutive patients who received a kidney transplant at our center. Measurements were made at the time of transplantation and six months later. RESULTS: There was a significant reduction after transplantation in the CXCR3highCD4+/CCR4highCD4+ balance (10.68±20.28 vs. 2.01±3.15, p=0.001). Separate analysis of each subset showed a significant reduction after transplantation in CXCR3highCD4+ (2.37±2.75 vs. 1.49±2.66, p=0.010) but no difference in CCR4highCD4+ (0.83±1.01 vs. 1.01±1.12, p=0.812). CONCLUSION: Prior to kidney transplantation uremic patients have an immunologic activation with Th1 polarization (studied by analyzing the CXCR3highCD4+ and CCR4highCD4+ populations) that falls after transplantation. This can be monitored with the CXCR3highCD4+ lymphocyte subset. This may help understand the pathologic mechanisms intervening in immunologic dysfunction of kidney grafts.

Long-term improvement of deceased donor renal allograft survival since 1996: a single transplant center study.

BACKGROUND: The rate of acute rejection (AR) has decreased significantly, but whether this is associated with improvement in long-term graft survival is controversial. METHODS: We analyzed 1445 consecutive adult deceased donor kidney transplant recipients from 1985 to 2005, over two periods (1985-1995 vs. 1996-2005) to compare long-term graft survival. RESULTS: The second period was associated with older donors and recipients and a reduction in AR. A significant increase of 10.1 months at 11 years was seen in death-censored graft survival in 1996 to 2005. For this posttransplant time, graft half-life was 10.8 years in 1985 to 1995, while at this point in the second period 62% of recipients had a functioning graft. The yearly increase in serum creatinine was less pronounced in the latter period (0.05 mg/dL vs. 0.02 mg/dL, P<0.01). No difference was found in patient survival. Cox analysis showed that donor age (HR 1.02, P<0.001), AR (HR 1.72, P<0.001), panel-reactive antibody at transplantation (HR 1.01, P<0.001), and serum creatinine at 1 year (HR 2.01, P<0.001) had a negative impact on graft outcome. By contrast, the use of mycophenolate mofetil was associated with a 24% reduction in graft loss rate (HR 0.76, P<0.05). CONCLUSION: Long-term graft survival and renal function have improved in renal transplant recipients since 1996.

Effect of the immunosuppressive treatment on long-term renal graft survival.

BACKGROUND: Although new immunosuppressive agents have improved the results of renal transplants (RTs), long-term graft loss remains high. We evaluated the impact of different immunosuppressive regimens on patient and graft survival. METHODS: Data from 3365 patients receiving cadaver RTs in Spain during the years 1990, 1994 and 1998 were retrospectively analysed. All data were entered into a specially designed database. Graft and patient survival rates were estimated by the Cox regression method and results expressed as percentage survival. A maximum-likelihood estimate of the projected graft half-life (median value) was calculated by Weibull regression. RESULTS: In 1990 graft and patient survival differed significantly from the other treatment years (P = 0.0006 and P = 0.0101, respectively). The risk of graft loss was significantly higher for cyclosporine (CsA), prednisone (P) and azathioprine (Az) than for CsA + P, which in turn was higher than for CsA + P plus polyclonal antibodies [antilymphocyte globulin (ALG)/antithymocyte globulin (ATG)]. Risk of patient death was also significantly higher for CsA + P + Az than for CsA + P. No significant differences between treatment groups were found in graft and patient survival for 1994 and 1998. The projected median graft life for patients with the most used immunosuppressive regimen for each year was 12.9 years for CsA + P + Az and 15.6 years for CsA + P plus mycophenolate mofetil (MMF). CONCLUSIONS: Triple therapy with Az in 1990 and 1994 and with MMF in 1998 were the most frequently used immunosuppressive regimens in the Spanish kidney transplant population. The best results were seen after induction therapy with polyclonal antibodies.

Mycophenolate mofetil reduces deterioration of renal function in patients with chronic allograft nephropathy. A follow-up study by the Spanish Cooperative Study Group of Chronic Allograft Nephropathy.

BACKGROUND: Although studies have shown that mycophenolate mofetil (MMF) with cyclosporine (CsA) and prednisone can reduce the incidence of acute rejection and increase the half-life of the graft, the effects of MMF on established chronic allograft nephropathy (CAN) are controversial. METHODS: We studied 121 patients with biopsy-proven CAN, 59 treated with CsA and prednisone and 62 treated with triple-drug therapy with azathioprine. At inclusion, each group received 2 g per day of MMF and azathioprine was stopped. Renal function was measured by the glomerular filtration rate (GFR) obtained by creatinine clearance (Cockcroft-Gault) and monitored by the slope of the GFR, adjusted using linear regression. RESULTS: The median follow-up, after incorporation of MMF, was 36 (13-36) months, with 103 (85.1%) having a full 3-year follow-up. Before the introduction of MMF, there was progressive deterioration in renal function (GFR: 54.8+/-20.9 vs. 39.7+/-14.0 mL/min, P<0.001). After introduction of MMF, renal function remained stable (GFR: 39.7+/-14.0 vs. 41.3+/-10.8 mL/min, P=NS), with a significant change in the slope of the GFR (-0.0144 vs. +0.00045, P<0.001). In 65 patients in whom CsA blood levels remained unchanged during follow-up (148.0+/-65.6 vs. 154.1+/-58.2, P=NS), the slope of the GFR showed a reduction in loss of renal function (-0.0147 vs. -0.0001, P<0.001). CONCLUSIONS: Treatment with MMF reduced the progressive deterioration of renal function in patients with CAN, independently of the blood levels of CsA.