Efficacy and safety of oral fosfomycin for asymptomatic bacteriuria in kidney transplant recipients: Results from a Spanish multicenter cohort.

Current guidelines recommend against systematic screening or treating asymptomatic bacteriuria (AB) among kidney transplant (KT) recipients, although the evidence regarding episodes occurring early after transplantation or in the presence of anatomical abnormalities is inconclusive. Oral fosfomycin may constitute a good option for the treatment of post-transplant AB, particularly due to the emergence of multidrug-resistant (MDR) uropathogens. Available clinical evidence supporting its use in this specific setting, however, remains scarce. We performed a retrospective study in 14 Spanish institutions from January 2005 to December 2017. Overall, 137 episodes of AB diagnosed in 133 KT recipients treated with oral fosfomycin (calcium and trometamol salts) with a test-of-cure urine culture within the first 30 days were included. Median time from transplantation to diagnosis was 3.1 months (interquartile range [IQR]: 1.1 - 10.5). Most episodes (96.4% [132/137]) were caused by gram-negative bacteria (GNB), and 56.9% (78/137) were categorized as MDR (extended-spectrum ß-lactamase-producing Enterobacterales [20.4%] and carbapenem-resistant GNB [2.9%]). Rate of microbiological failure at month 1 was 40.1% (95% confidence interval [95%CI]: 31.9 - 48.9) for the whole cohort and 42.3% (95%CI: 31.2 - 54.0) for episodes due to MDR pathogens. Previous urinary tract infection (odds ratio [OR]: 2.42; 95%CI: 1.11 - 5.29; P-value = 0.027) and use of fosfomycin as salvage therapy (OR: 8.31; 95%CI: 1.67 - 41.35; P-value = 0.010) were predictors of microbiological failure. No severe treatment-related adverse event were detected. Oral fosfomycin appears to be a suitable and safe alternative for the treatment (if indicated) of AB after KT, including those episodes due to MDR uropathogens.

Recurrence of immune complex and complement-mediated membranoproliferative glomerulonephritis in kidney transplantation.

INTRODUCTION: Membranoproliferative glomerulonephritis (MPGN) represents a histologic pattern of glomerular injury that may be due to several aetiologies. Few studies have comprehensively analysed the recurrence of MPGN according to the current classification system. METHODS: We collected a multicentre, retrospective cohort of 220 kidney graft recipients with biopsy-proven native kidney disease due to MPGN between 1981 and 2021 in 11 hospitals. Demographic, clinical and histologic parameters of prognostic interest were collected. The main outcomes were time to kidney failure, time to recurrence of MPGN and disease remission after recurrence. RESULTS: The study group included 34 complement-mediated and 186 immune complex-mediated MPGN. A total of 81 patients (37%) reached kidney failure in a median follow-up of 79 months. The main predictors of this event were the development of rejection episodes and disease recurrence. In all, 54 patients (25%) had a disease recurrence in a median of 16 months after kidney transplantation. The incidence of recurrence was higher in patients with dysproteinaemia (67%) and complement-mediated MPGN (62%). In the multivariable model, complement-mediated MPGN emerged as a predictor of recurrence. A total of 33 patients reached kidney failure after recurrence. The main determinants of no remission were early time to recurrence (<15 months), estimated glomerular filtration rate <30 mL/min/1.73 m2 and serum albumin <3.5 g/dL at the time of recurrence. CONCLUSIONS: One-fourth of the patients with native kidney disease due to MPGN developed clinical recurrence in the allograft, especially in cases with complement-mediated disease or in those associated with dysproteinaemia. The kidney outcomes of disease recurrence with currently available therapies are heterogeneous and thus more effective and individualized therapies are needed.

Secondary antibody deficiency is associated with development of infection in kidney transplantation: Results of a multicenter study.

BACKGROUND: We performed a multicenter study to assess the association between secondary antibody deficiency (immunoglobulin G [IgG] hypogammaglobulinemia combined with low levels of specific antibodies) and development of infection in kidney transplantation. METHODS: We prospectively analyzed 250 adult kidney recipients at four centers. The assessment points were before transplantation and 7 and 30 days after transplantation. The immune parameters were as follows: IgG, IgA, and IgM and complement factors C3 and C4 tested by nephelometry; specific IgG antibodies to cytomegalovirus (CMV) and IgG and IgG2 antibodies to pneumococcal polysaccharide (anti-PPS) determined using enzyme-linked immunosorbent assay. The clinical follow-up period lasted 6 months. The clinical outcomes were CMV disease and recurrent bacterial infections requiring antimicrobial therapy. STATISTICS: Multivariate logistic regression. RESULTS: At day 7, IgG hypogammaglobulinemia (IgG levels < 700 mg/dL) combined with low IgG anti-CMV antibody titers (defined as levels < 10 000 units) was present in 12% of kidney recipients. IgG hypogammaglobulinemia combined with low IgG anti-PPS antibody titers (defined as levels < 10 mg/dL) at 1 month after kidney transplantation were recorded in 16% of patients. At day 7 the combination of IgG hypogammaglobulinemia and low anti-CMV titers was independently associated with the development of CMV disease (odds ratio [OR], 6.95; 95% confidence interval [CI], 1.17-41.31; P = .033). At day 30 after transplantation, the combination of IgG < 700 mg/dL and IgG anti-PPS < 10 mg/dL, was independently associated with recurrent bacterial infection (OR, 5.942; 95% CI, 1.943-18.172; P = .002). CONCLUSION: In a prospective multicenter study, early immunologic monitoring of secondary antibody deficiency proved useful for the identification of kidney recipients who developed severe infection.

Oral fosfomycin for the treatment of lower urinary tract infections among kidney transplant recipients-Results of a Spanish multicenter cohort.

Oral fosfomycin may constitute an alternative for the treatment of lower urinary tract infections (UTIs) in kidney transplant recipients (KTRs), particularly in view of recent safety concerns with fluroquinolones. Specific data on the efficacy and safety of fosfomycin in KTR are scarce. We performed a retrospective study in 14 Spanish hospitals including KTRs treated with oral fosfomycin (calcium and trometamol salts) for posttransplant cystitis between January 2005 and December 2017. A total of 133 KTRs developed 143 episodes of cystitis. Most episodes (131 [91.6%]) were produced by gram-negative bacilli (GNB), and 78 (54.5%) were categorized as multidrug resistant (including extended-spectrum ß-lactamase-producing Enterobacteriaceae [14%] or carbapenem-resistant GNB [3.5%]). A median daily dose of 1.5 g of fosfomycin (interquartile range [IQR]: 1.5-2) was administered for a median of 7 days (IQR: 3-10). Clinical cure (remission of UTI-attributable symptoms at the end of therapy) was achieved in 83.9% (120/143) episodes. Among those episodes with follow-up urine culture, microbiological cure at month 1 was achieved in 70.2% (59/84) episodes. Percutaneous nephrostomy was associated with a lower probability of clinical cure (adjusted odds ratio: 10.50; 95% confidence interval: 0.98-112.29; P = 0.052). In conclusion, fosfomycin is an effective orally available alternative for treating cystitis among KTRs.

Strict selection criteria in uncontrolled donation after circulatory death provide excellent long-term kidney graft survival.

BACKGROUND: We aimed to report our experience in uncontrolled donation after circulatory death (uDCD) kidney transplantation applying a strict donor selection and preservation criteria. METHODS: All kidney recipients received a graft from a local uDCD. As controls, we included all renal transplants from local standard criteria donation after brain death (SDBD) donors. Normothermic regional perfusion was the preservation method in all cases. RESULTS: A total of 19 kidneys from uDCD donors were included and 67 controls. Delayed graft function (DGF) was higher in the uDCD group (42.1% vs 17.9%; P = .033), whereas no differences were observed in primary nonfunction (0% cases vs 3% controls; P = .605). The estimated glomerular filtration rate was identical in both groups. No differences were observed in graft survival censored for death between the uDCD and the SDBD groups at 1-year (100% vs 95%) or 5-year follow-up (92% vs 91%). uDCD kidney recipients did not have higher risk of graft loss in the multivariate analysis adjusted by recipient age, cold ischemic time, presence of DGF, and second kidney transplant (HR: 0.4; 95% CI 0.02-6; P = .509). CONCLUSIONS: Obtaining renal grafts from uDCD is feasible in a small city and provides similar outcomes compared to standard DBD donors.

High Pretransplant BAFF Levels and B-cell Subset Polarized towards a Memory Phenotype as Predictive Biomarkers for Antibody-Mediated Rejection.

Antibody-mediated rejection (AbMR) is one of the leading causes of graft loss in kidney transplantation and B cells play an important role in the development of it. A B-cell activating factor (BAFF) is a cytokine involved in B cell ontogeny. Here, we analyzed whether B cell maturation and the effect of B cell soluble factors, such as BAFF could be involved in AbMR. Serum BAFF levels and B and T cell subpopulations were analyzed 109 kidney transplant patients before transplantation and at 6 and 12 months after kidney transplantation. Pretransplant serum BAFF levels as well as memory B cell subpopulations were significantly higher in those patients who suffered clinical AbMR during the first 12 months after kidney transplantation. Similar results were observed in the prospective analysis of patients with subclinical antibody-mediated rejection detected in the surveillance biopsy performed at 12 months after kidney transplantation. A multivariate analysis confirmed the independent role of BAFF in the development of AbMR, irrespective of other classical variables. Pretransplant serum BAFF levels could be an important non-invasive biomarker for the prediction of the development of AbMR and posttransplant increased serum BAFF levels contribute to AbMR.

A proliferation-inducing ligand increase precedes IgA nephropathy recurrence in kidney transplant recipients.

BACKGROUND: IgA nephropathy (IgAN) may recur in kidney transplant recipients. B-cell-activating factor (BAFF), a proliferation-inducing ligand (APRIL), and α-defensins are involved in the pathogenesis of native IgAN; however, their role on IgAN recurrence has not been previously analyzed. METHODS: Thirty-five patients with IgAN who received a kidney transplant in our center between January 1, 1993, and December 31, 2015, were included. Recurrence was diagnosed and ruled out in 14 and 11 patients, respectively, by indication biopsies. Pre-transplant, 6-month, 1-, 3-, and 5-year sera selected to measure BAFF, APRIL, and defensin by ELISA. RESULTS: Six months post-transplantation, APRIL levels (300.1 vs 1203.8 pg/mL, P = 0.033) and the mean APRIL values from 6 months to 3 years (409.8 vs 1258.0 pg/mL, P = 0.003) were higher in recurrent patients. Both 6-month APRIL levels (AUC-ROC 0.753, P = 0.033) and mean APRIL values (AUC-ROC 0.844, P = 0.004) discriminated patients with recurrence risk. By logistic regression, APRIL at 6 months (P = 0.044) and mean APRIL (P = 0.021) related to the risk of IgAN recurrence independently. Neither BAFF nor defensin related to recurrence. CONCLUSIONS: Serum APRIL increased at 6 months and mean APRIL remained higher the first 3 years in patients in whom IgAN was going to recur.

Treatment of chronic antibody mediated rejection with intravenous immunoglobulins and rituximab: A multicenter, prospective, randomized, double-blind clinical trial.

There are no approved treatments for chronic antibody mediated rejection (ABMR). We conducted a multicenter, prospective, randomized, placebo-controlled, double-blind clinical trial to evaluate efficacy and safety of intravenous immunoglobulins (IVIG) combined with rituximab (RTX) (EudraCT 2010-023746-67). Patients with transplant glomerulopathy and anti-HLA donor-specific antibodies (DSA) were eligible. Patients with estimated glomerular filtration rate (eGFR) <20 mL/min per 1.73m2 and/or severe interstitial fibrosis/tubular atrophy were excluded. Patients were randomized to receive IVIG (4 doses of 0.5 g/kg) and RTX (375 mg/m2 ) or a wrapped isovolumetric saline infusion. Primary efficacy variable was the decline of eGFR at one year. Secondary efficacy variables included evolution of proteinuria, renal lesions, and DSA at 1 year. The planned sample size was 25 patients per group. During 2012-2015, 25 patients were randomized (13 to the treatment and 12 to the placebo group). The planned patient enrollment was not achieved because of budgetary constraints and slow patient recruitment. There were no differences between the treatment and placebo groups in eGFR decline (-4.2 ± 14.4 vs. -6.6 ± 12.0 mL/min per 1.73 m2 , P-value = .475), increase of proteinuria (+0.9 ± 2.1 vs. +0.9 ± 2.1 g/day, P-value = .378), Banff scores at one year and MFI of the immunodominant DSA. Safety was similar between groups. These data suggest that the combination of IVIG and RTX is not useful in patients displaying transplant glomerulopathy and DSA.

Different in vitro proliferation and cytokine-production inhibition of memory T-cell subsets after calcineurin and mammalian target of rapamycin inhibitors treatment.

Calcineurin inhibitors (CNI) and mammalian target of rapamycin inhibitors (mTORi) are the main immunosuppressants used for long-term maintenance therapy in transplant recipients to avoid acute rejection episodes. Both groups of immunosuppressants have wide effects and are focused against the T cells, although different impacts on specific T-cell subsets, such as regulatory T cells, have been demonstrated. A greater knowledge of the impact of immunosuppression on the cellular components involved in allograft rejection could facilitate decisions for individualized immunosuppression when an acute rejection event is suspected. Memory T cells have recently gained focus because they might induce a more potent response compared with naive cells. The impact of immunosuppressants on different memory T-cell subsets remains unclear. In the present study, we have studied the specific impact of CNI (tacrolimus) and mTORi (rapamycin and everolimus) over memory and naive CD4(+) T cells. To do so, we have analysed the proliferation, phenotypic changes and cytokine synthesis in vitro in the presence of these immunosuppressants. The present work shows a more potent effect of CNI on proliferation and cytokine production in naive and memory T cells. However, the mTORi permit the differentiation of naive T cells to the memory phenotype and allow the production of interleukin-2. Taken together, our data show evidence to support the combined use of CNI and mTORi in transplant immunosuppression.

ABCB1 (MDR-1) pharmacogenetics of tacrolimus in renal transplanted patients: a Next Generation Sequencing approach.

BACKGROUND: A CYP3A5 gene polymorphism is the main determinant of Tacrolimus (Tac) dose requirements among renal transplanted patients. In spite of the utility of CYP3A5 genotyping to predict the Tac-dose, many patients exhibit an out of range blood Tac level and it is thus likely that other genes/polymorphisms contribute to define Tac bioavailability. To address this issue we searched for coding sequence variants in the ABCB1/MDR1 gene in renal transplanted patients treated with Tac and who had out of the range blood levels. METHODS: We studied 100 renal transplanted patients treated with Tac, 60 of whom had Tac blood levels below (n=39) and above (n=21) the target range (10-15 ng/mL) at 1 week post-transplant. The DNA was subjected to multiplex amplification followed by massive parallel semiconductor sequencing in the Ion Torrent personal genome machine. RESULTS: We found four missense changes, all reported and present in cases above and below the blood Tac target. In addition, we did not find differences in the allele and genotype frequencies for the common rs1045642 polymorphism (p.I1145I) between the groups. CONCLUSIONS: Our results suggested that the ABCB1 variants had no effect on the risk of showing out of range Tac blood levels among renal transplanted patients.

Enhanced posttransplant management of patients with diabetes improves patient outcomes.

The survival of patients with diabetes mellitus in the general population has improved in recent years. Here we assessed whether similar trends have occurred in 1688 kidney recipients, including 413 with diabetes prior to transplant between 1996 and 2007. Compared to patients without diabetes, the 5-year mortality was significantly increased (hazard ratio (HR) 2.68 (1.95-3.69)) due to higher cardiovascular-, infection-, and malignancy-related deaths in those with diabetes. However, 5-year mortality in patients with diabetes significantly declined over time (HR 0.883 (0.817-0.954)), narrowing the mortality difference between patients with and those without diabetes and in more recent years largely eliminating it. Post transplant, patients with diabetes experienced a significant decline in major fatal/nonfatal cardiac events (HR 0.853 (0.782-0.930)) and infectious deaths over time. In contrast, neither cardiac events nor overall mortality declined in recipients without diabetes. The decline in mortality due to diabetes did not relate to a reduced pretransplant risk profile and was independent of posttransplant variables. The use of cardioprotective medications and glycemic control improved over time post transplant. Furthermore, graft function and serum albumin significantly improved over time and these parameters related to better survival (albumin, HR 0.365 (0.223-0.599); eGFR, HR 0.803 (0.756-0.852)). Thus, survival of kidney recipients with diabetes mellitus has improved markedly since 1996 likely reflecting, at least in part, enhanced posttransplant management and outcomes.

Predictive factors of allosensitization in renal transplant patients switched from calcineurin to mTOR inhibitors.

Conversion of kidney-transplant recipients from calcineurin inhibitors to mTOR inhibitors has been suggested to be a risk factor for increased alloimmune response. We have analyzed the development of new HLA-antibodies (HLA-Abs) early after conversion in 184 patients converted in stable phase at our hospital and compared with a control group of nonconverted comparable 63 transplants. Using single-antigen solid-phase immunoassay analysis, a preconversion and a 3-6 months postconversion sera were prospectively analyzed in every patient for the appearance of new HLA-Abs. Renal function at 2 years postconversion and cumulative graft survival were compared between groups. In 16 patients, new HLA-Abs (3-DSA and 13-NonDSA), not present at the moment of conversion, were detected (8.7% vs. 3.1% in the control group). The type of mTORi used, type of CNI preconversion, the presence of steroids, time of conversion, or indication for conversion did not have influence on this effect but the presence of HLA-Abs before conversion highly correlated with the appearance of new specificities. Patients with de novo HLA-Abs showed a trend to worst graft function and survival. In conclusion, conversion to mTORi can be followed by early appearance of de novo HLA-Abs, especially in patients with HLA-Abs preconversion, and this complication should be screened early after conversion.

Consequences of Nephrotic Proteinuria and Nephrotic Syndrome after Kidney Transplant.

Proteinuria is the main predictor of kidney graft loss. However, there is little information regarding the consequences of nephrotic proteinuria (NP) and nephrotic syndrome (NS) after a kidney transplant. We aimed to describe the clinical and histopathological characteristics of kidney recipients with nephrotic-range proteinuria and compare the graft surveillance between those who developed NS and those who did not. A total of 204 patients (18.6% of kidney transplants in the study period) developed NP, and 68.1% of them had NS. Of the 110 patients who underwent a graft biopsy, 47.3% exhibited ABMR, 21.8% the recurrence of glomerulonephritis, 9.1% IFTA, and 7.3% de novo glomerulonephritis. After a median follow-up of 97.5 months, 64.1% experienced graft loss. The graft survival after the onset of NP declined from 75.8% at 12 months to 38% at 5 years, without significant differences between those with and those without NS. Patients who developed NS fewer than 3 months after the onset of NP exhibited a significantly higher risk of death-censored graft loss (HR: 1.711, 95% CI: 1.147-2.553) than those without NS or those with late NS. In conclusion, NP and NS are frequent conditions after a kidney transplant, and they imply extremely poor graft outcomes. The time from the onset of NP to the development of NS is related to graft survival.

Tubulo-interstitial inflammation increases the risk of graft loss after the recurrence of IgA nephropathy.

Background: Immunoglobulin A nephropathy (IgAN) is the most frequent recurrent disease in kidney transplant recipients and its recurrence contributes to reducing graft survival. Several variables at the time of recurrence have been associated with a higher risk of graft loss. The presence of clinical or subclinical inflammation has been associated with a higher risk of kidney graft loss, but it is not precisely known how it influences the outcome of patients with recurrent IgAN. Methods: We performed a multicentre retrospective study including kidney transplant recipients with biopsy-proven recurrence of IgAN in which Banff and Oxford classification scores were available. 'Tubulo-interstitial inflammation' (TII) was defined when 't' or 'i' were ≥2. The main endpoint was progression to chronic kidney disease (CKD) stage 5 or to death censored-graft loss (CKD5/DCGL). Results: A total of 119 kidney transplant recipients with IgAN recurrence were included and 23 of them showed TII. Median follow-up was 102.9 months and 39 (32.8%) patients reached CKD5/DCGL. TII related to a higher risk of CKD5/DCGL (3 years 18.0% vs 45.3%, log-rank 7.588, P = .006). After multivariate analysis, TII remained related to the risk of CKD5/DCGL (HR 2.344, 95% CI 1.119-4.910, P = .024) independently of other histologic and clinical variables. Conclusions: In kidney transplant recipients with IgAN recurrence, TII contributes to increasing the risk of CKD5/DCGL independently of previously well-known variables. We suggest adding TII along with the Oxford classification to the clinical variables to identify recurrent IgAN patients at increased risk of graft loss who might benefit from intensified immunosuppression or specific IgAN therapies.

Post-COVID-19 syndrome, inflammation and insulin resistance: a retrospective cohort study.

BACKGROUND: COVID-19-induced diabetes is a novel and enigmatic disease. Our aim was to evaluate a possible relationship between post-COVID-19 syndrome (PCS) and increased insulin resistance (IR) in non-diabetic outpatients after mild COVID-19. METHODS: Repeated measures design. Three evaluations [1E (pre-COVID, baseline), 2E (3 months post-COVID) and 3E (21 months post-COVID)] were performed, directed to PCS+ and PCS- subjects. Triglyceride-glucose (TyG) index ≥8.74 was considered IR, and albumin-to-globulin ratio (AGR) <1.50, inflammation. RESULTS: We analyzed 112 individuals (median [IQR] age=44 [20] years, 58% women, 36 PCS+, 76 PCS-). PCS+ with very low basal IR (TyG <7.78, lowest quartile) showed a reduced inflammatory burden (basal AGR=1.81 [0.4] vs. 1.68 [0.2] in 2E; P=0.23), and increased TyG across evaluations (from basal 7.62 [0.2] to 8.29 [0.5]; P=0.018]. Conversely, PCS+ subjects with high basal TyG (TyG ≥8.65, highest quartile) did not show significant variations in TyG, but a greater inflammatory load (basal AGR=1.69 [0.3] vs. 1.44 [0.3] in 2E; P=0.10). In multivariable models addressing groups with reduced basal IR (TyG <8.01), PCS has been a consistent predictor for TyG, after adjusting for confounders. Partial correlation and multivariable analyses showed similarities involving acute polysymptomatic COVID-19 and PCS regarding IR. CONCLUSIONS: PCS was associated with increased IR, being more evident when the baseline degree of IR was very low. PCS and increased IR were separately associated with inflammation. Acute polysymptomatic COVID-19 and PCS could be clinical expressions of underlying inflammatory state, which in turn may also trigger IR.

Cystatin C and albuminuria as predictors of long-term allograft outcomes in kidney transplant recipients.

Although cystatin C (Cys) and albuminuria (Alb) are predictors of end-stage renal disease in the general population, there are limited data about the performance of these markers alone or combined with respect to the prediction of the kidney transplant outcome. We assessed the ability of one-yr creatinine (Cr), MDRD equation, Cys, Hoek equation, Alb, the logarithm of albuminuria (LogAlb), and two products of these variables for predicting death-censored graft loss (DCGL) in 127 kidney transplant recipients. Mean follow-up time was 5.6 ± 1.7 yr. During this time, 18 patients developed DCGL. The area under the receiver operating characteristic curve for DCGL ranged from 71.1% to 85.4%, with Cys*LogAlb being the best predictor. Cys-based variables and variables combining LogAlb and renal function estimates have better discrimination ability than Cr-based variables alone. After multivariate analysis, quartiles of all one-yr variables (except of Cr and MDRD) were independent predictors for DCGL. Predictors combining Alb and a Cr- or Cys-based estimate of renal function performed better than those markers alone to predict DCGL. Cys-based predictors performed better than Cr-based predictors. Using a double-marker in kidney transplantation, it is possible to identify the highest risk group in which to prioritize specialty care.

Aggressive lung donor management increases graft procurement without increasing renal graft loss after transplantation.

BACKGROUND: To determine the impact of an aggressive protocol on the rate of lung grafts available for transplant. We analyzed the impact of this management on kidney graft survival after kidney transplantation. METHODS: A cohort study. Lung donors and kidney recipients from 2009 and 2010 were considered the prospective cohort with 2003-2008 as the historical control period. The number of lungs available for transplantation was the main outcome measures. For recipients, kidney graft survival was the main outcome measure. RESULTS: We quadrupled the number of lung donors in the period 2009-2010 compared with the historical control. Management in the prospective cohort included higher use of positive end-expiratory pressure (PEEP) (p < 0.0001), increased use of hormonal resuscitation therapy (HRT) (p < 0.0001), and lower level of central venous pressure (p < 0.05) than historical control. The probability of renal graft survival at one yr after transplant was 88.6% (CI 95%: 74.8-95.1) in historical control and 94.7% (CI 95%: 81-98.7%) in the prospective cohort (p = 0.226). CONCLUSIONS: Aggressive management strategy in potential lung donors, which includes ventilator recruitment maneuvers, PEEP ≥ 8 cm H(2)O, the use of HRT, and restrictive fluid balance increases the rate of lung grafts available for transplantation without adverse effect on kidney graft survival.

Torque Teno Virus Load Predicts Opportunistic Infections after Kidney Transplantation but Is Not Associated with Maintenance Immunosuppression Exposure.

Measuring the non-pathogenic Torque Teno Virus (TTV) load allows assessing the net immunosuppressive state after kidney transplantation (KTx). Currently, it is not known how exposure to maintenance immunosuppression affects TTV load. We hypothesized that TTV load is associated with the exposure to mycophenolic acid (MPA) and tacrolimus. We performed a prospective study including 54 consecutive KTx. Blood TTV load was measured by an in-house PCR at months 1 and 3. Together with doses and trough blood levels of tacrolimus and MPA, we calculated the coefficient of variability (CV), time in therapeutic range (TTR) and concentration/dose ratio (C/D) of tacrolimus, and the MPA-area under the curve (AUC-MPA) at the third month. TTV load at the first and third month discriminated those patients at risk of developing opportunistic infections between months 1 and 3 (AUC-ROC 0.723, 95%CI 0.559-0.905, p = 0.023) and between months 3 and 6 (AUC-ROC 0.778, 95%CI 0.599-0.957, p = 0.028), respectively, but not those at risk of acute rejection. TTV load did not relate to mean tacrolimus blood level, CV, TTR, C/D and AUC-MPA. To conclude, although TTV is a useful marker of net immunosuppressive status after KTx, it is not related to exposure to maintenance immunosuppression.

High exposure to tacrolimus is associated with spontaneous remission of recurrent membranous nephropathy after kidney transplantation.

Introduction: We aimed to characterize the incidence and clinical presentation of membranous nephropathy (MN) after kidney transplantation (KT), and to assess allograft outcomes according to proteinuria rates and immunosuppression management. Methods: Multicenter retrospective cohort study including patients from six Spanish centers who received a KT between 1991-2019. Demographic, clinical, and histological data were collected from recipients with biopsy-proven MN as primary kidney disease (n = 71) or MN diagnosed de novo after KT (n = 4). Results: Up to 25.4% of patients with biopsy-proven MN as primary kidney disease recurred after a median time of 18.1 months posttransplant, without a clear impact on graft survival. Proteinuria at 3-months post-KT was a predictor for MN recurrence (rMN, HR 4.28; P = 0.008). Patients who lost their grafts had higher proteinuria during follow-up [1.0 (0.5-2.5) vs 0.3 (0.1-0.5) g/24 h], but only eGFR after recurrence treatment predicted poorer graft survival (eGFR < 30 ml/min: RR = 6.8). We did not observe an association between maintenance immunosuppression and recurrence diagnosis. Spontaneous remission after rMN was associated with a higher exposure to tacrolimus before recurrence (trough concentration/dose ratio: 2.86 vs 1.18; P = 0.028). Up to 94.4% of KT recipients received one or several treatments after recurrence onset: 22.2% rituximab, 38.9% increased corticosteroid dose, and 66.7% ACEi/ARBs. Only 21 patients had proper antiPLA2R immunological monitoring. Conclusions: One-fourth of patients with biopsy-proven MN as primary kidney disease recurred after KT, without a clear impact on graft survival. Spontaneous remission after rMN was associated with a higher exposure to tacrolimus before recurrence.