Long-term Follow-up of Living Kidney Donors With Chronic Kidney Disease at 1 Year After Nephrectomy

BACKGROUND

Although renal function recovery of living kidney donors has been reported in a number of studies, many patients show poor recovery, and the long-term prognosis of these patients has not been well studied. In this investigation we explored the long-term prognosis of renal function in patients with chronic kidney disease (CKD) at 1 year after nephrectomy.

METHODS

Patients who underwent donor nephrectomy during the period from March 2006 to April 2014, with a follow-up creatinine study at 1 year postoperatively and more than 3 years of follow-up, were included in the study. Creatinine and estimated glomerular filtration rate (eGFR, using the Modification of Diet in Renal Disease formula) before and after surgery were studied. Age, sex, history of hypertension or diabetes, body mass index, blood pressure, complete blood count, preoperative routine serum chemistry, and urine study results were reviewed.

RESULTS

Among 841 patients who had donor nephrectomy, 362 were included in the study. There were 111 patients (30.6%) with eGFR <60 mL/min/1.73 m² at 1 year postsurgery, and the median follow-up period was 62.8 months (interquartile range [IQR] 42.0-86.3 months). The maximum eGFR after 3-year follow-up was studied, and 48 patients (43.2%) never recovered eGFR to >60 mL/min/1.73 m². Age, history of hypertension, preoperative eGFR, and eGFR at 1 year were predictive factors at univariate analysis. Multivariate analysis of these factors was studied, and age (52.5 [IQR 47-55.7] vs 47 [IQR 7-53] years, odds ratio [OR] 1.1, 95% confidence interval [CI] 1.02-1.15, P = .007), history of hypertension (16.7% vs 1.6%, OR 10.0, 95% CI 1.09-92.49, P = .042), and eGFR at 1 year (53.9 [IQR 50.3-56.0] vs 57.0 [IQR 54.2-58.4] mL/min/1.73 m², OR 0.8, 95% CI 0.72-0.92, P = .002) remained as significant risk factors.

CONCLUSION

Of all living donors, 15.7% had CKD after >3 years of follow-up. Close observation is warranted when donors have CKD after 1 year follow-up, as 43.2% fail to recover renal function. Patients who are older, have a history of hypertension, and have low eGFR at 1-year follow-up are especially at risk.

Delayed Recovery of Renal Function After Donor Nephrectomy

BACKGROUND

Many living kidney donors are still at risk of chronic kidney disease (CKD) 1 year after nephrectomy. Although some donors still experience poor renal function, many exhibit delayed recovery of renal function afterwards. We studied the factors related to delayed recovery of renal function in patients with CKD at 1 year after nephrectomy.

METHODS

Patients who underwent donor nephrectomy from March 2006 to April 2014 with a follow-up creatinine study at 1 month, 6 months, 1 year, and after 3 years of follow-up were included in the study. Age, sex, history of hypertension or diabetes, body mass index, blood pressure, complete blood cell count, preoperative routine serum chemistry, and urine study results were reviewed.

RESULTS

Among 275 donors, 83 (30.2%) who had an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² at 1 year of follow-up were included in the study, and the eGFR was observed during a median follow-up of 62.0 months (interquartile range [IQR], 48.9-83.1 months). Those who had improvements in eGFR of >5 mL/min/1.73 m² were included in the recovery group (n = 48 [57.8%]), and those who did not were included in the nonrecovery group (n = 35 [42.2%]). The preoperative and 1-year follow-up eGFR did not differ significantly between the 2 groups, and the maximum eGFR after 3 years was higher in the recovery group (68.68 mL/min/1.73 m² [IQR, 61.81-75.64 mL/min/1.73 m²] vs 55.63 mL/min/1.73 m² [IQR, 51.73-58.29 mL/min/1.73 m²]; P < .001). The recovery group was more likely to have a history of hypertension (4.2% vs 20%; P = .032), a lower body mass index (24.11 kg/m² [IQR, 22.04-25.20 kg/m²] vs 25.25 kg/m² [IQR, 23.23-26.44 kg/m²]; P = .01), and a lower preoperative uric acid level (4.7 mg/dL [IQR, 3.8-5.4 mg/dL] vs 5.3 mg/dL [IQR, 4.4-6.2 mg/dL]; P = .031). After multivariate logistic regression analysis, history of hypertension (odds ratio, 0.131; P = .022) and uric acid level (odds ratio, 0.641; P = .036,) remained as significant factors.

CONCLUSIONS

Although 30.2% of donors had CKD at 1 year after nephrectomy, 57.8% reported improved renal function. Those with a history of hypertension and high preoperative uric acid levels were less likely to have improvements in renal function and required close follow-up.

Impact of Korea Network for Organ Sharing Expanded Donor Criteria on Delayed Graft Fuction in Kidney Transplantation: A Single-Center Experience

BACKGROUND

The shortage of donor organs has been a major challenge in transplantation. In an effort to reduce the donor shortage, kidney transplantation (KT) using expanded criteria donors (ECD) was encouraged. In Korea, transplantation centers used the Korea Network for Organ Sharing (KONOS) ECD criteria, which is different from the United Network for Organ Sharing (UNOS) criteria. The aim of this study is to evaluate the predictive power of KONOS criteria on delayed graft function (DGF) in comparison to UNOS criteria.

METHODS

A total of 376 recipients who underwent deceased donor kidney transplantation between January 2005 and December 2014 at Severance Hospital were retrospectively reviewed. Of these, 130 cases satisfied KONOS ECD, while the others followed KONOS standard criteria donor (SCD).

RESULTS

Donor age and history of hypertension was significantly higher with KONOS ECD than with KONOS SCD. In KONOS subgroup analysis, donor characteristics were different than with UNOS criteria. The incidence of DGF was higher in the KONOS ECD group than in the KONOS SCD group. However, UNOS ECD showed a high incidence of DGF compared to UNOS SCD with the same KONOS criteria. UNOS ECD was an independent risk factor for DGF in multivariate analysis. However, KONOS ECD was not a risk factor for DGF. Although glomerular filtration rate was inferior in the KONOS ECD group compared to the KONOS SCD group, the UNOS SCD group within the KONOS ECD group showed similar graft function compared to the KONOS SCD group.

CONCLUSION

KONOS criteria have a lower predictive power for DGF than UNOS criteria.

The clinicopathological relevance of pretransplant anti-angiotensin II type 1 receptor antibodies in renal transplantation

Background

Anti-angiotensin II type 1 receptor antibodies (AT1R-Abs) have been suggested as a risk factor for graft failure and acute rejection (AR). However, the prevalence and clinical significance of pretransplant AT1R-Abs have seldom been evaluated in Asia.

Methods

In this multicenter, observational cohort study, we tested the AT1R-Abs in pretransplant serum samples obtained from 166 kidney transplant recipients. Statistical analysis was used to set a threshold AT1R-Abs level at 9.05 U/mL.

Results

Pretransplant AT1R-Abs were detected in 98/166 (59.0%) of the analyzed recipients. No graft loss or patient death was reported during the study period. AT1R-Abs (+) patients had a significantly higher incidence of biopsy-proven AR than AT1R-Abs (-) patients (27.6 versus 10.3%, P = 0.007). Recipients with pretransplant AT1R-Abs had a 3.2-fold higher risk of AR within a year of transplantation (P = 0.006). Five study subjects developed microcirculation inflammation (score ≥2). Four of them were presensitized to AT1R-Abs. In particular, three patients had a high titer of anti-AT1R-Abs (>22.7 U/mL).

Conclusions

Pretransplant AT1R-Abs is an independent risk factor for AR, especially acute cellular rejection, and is possibly associated with the risk of antibody-mediated injury. Pretransplant assessment of AT1R-Abs may be useful for stratifying immunologic risks.

Successful kidney transplantation across a positive complement-dependent cytotoxicity crossmatch by using C1q assay-directed, bortezomib-assisted desensitization: A case report

RATIONALE

Human leukocyte antigen (HLA) is the major immunologic barrier in kidney transplantation (KT). Various desensitization protocols to overcome the HLA barrier have increased the opportunity for transplantation in sensitized patients. In addition, technological advances in solid-phase assays have permitted more comprehensive assessment of donor-specific antibodies. Although various desensitization therapies and immunologic techniques have been developed, the final transplantation decision is still based on the classic complement-dependent cytotoxicity (CDC) crossmatch (XM) technique. Some patients who fail to achieve negative XM have lost their transplant opportunities, even after receiving sufficient desensitization therapies.

PATIENT CONCERNS

A 57-year-old male with end-stage renal disease secondary to chronic glomerulonephritis was scheduled to have a second transplant from his son, but CDC XM was positive.

DIAGNOSES

Initial CDC XM (Initial T-AHG 1:32) and flow-cytometry XM were positive. Anti-HLA-B59 donor specific antibody was detected by Luminex single antigen assay.

INTERVENTIONS

Herein, we report a successful case of KT across a positive CDC XM (T-AHG 1:8 at the time of transplantation) by using C1q assay-directed, bortezomib-assisted desensitization. After confirming a negative conversion in the C1q donor-specific antibody, we decided to perform KT accepting a positive AHG-CDC XM of 1:8 at the time of transplantation.

OUTCOMES

The posttransplant course was uneventful and a protocol biopsy at 3 months showed no evidence of rejection. The patient had excellent graft function at 12 months posttransplant.

LESSONS

The results of XM test and solid-phase assay should be interpreted in the context of the individual patient.

Enhanced immune-modulatory effects of thalidomide and dexamethasone co-treatment on T cell subsets

Thalidomide (TM) has been reported to have anti-cancer and anti-inflammatory properties, and dexamethasone (DX) is known to reduce inflammation and inhibit production of inflammatory cytokines. Many studies have reported that combinatorial therapy with TM and DX is clinically used to treat multiple myeloma and lupus nephritis, but the mechanism responsible for its effects has not been elucidated. In this study, we determined that TM and DX co-treatment had an enhanced immune-modulatory effect on T cells through regulating the expression of co-stimulatory molecules. Splenic naive T cells from C57BL/6 mice were sort-purified and cultured for CD4⁺ T cell proliferation and regulatory T (Treg) cell conversion in the presence of TM and/or DX. Following incubation with the drugs, cells were collected and OX40, 4-1BB, and glucocorticoid-induced tumour necrosis factor receptor-related protein (GITR) expression was quantified by flow cytometry. TM (1 or 10 μm) decreased CD4⁺ T cell proliferation in a dose-dependent manner, whereas TM/DX (0·1 or 1 nm) co-treatment further decreased proliferation. Treg cell populations were preserved following drug treatment. Furthermore, expression of co-stimulatory molecules decreased upon TM/DX co-treatment in effector T (Teff) cells and was preserved in Treg cells. Splenic CD4⁺ T cells isolated from TM- and DX-treated mice exhibited the same patterns of Teff and Treg cell populations as observed in vitro. Considering the selective effect of TM on different T cell subsets, we suggest that TM may play an immunomodulatory role and that TM/DX combinatorial treatment could further enhance these immunomodulatory effects by regulating GITR, OX40, and 4-1BB expression in CD4⁺ T cells.

Reduction of Slit Diaphragm-associated Molecules by Sirolimus: Is it Enough to Induce Proteinuria?

Sirolimus (SRL), a mammalian target of rapamycin inhibitor, is widely used in transplantation, but the mechanisms whereby it induces adverse effects, such as proteinuria and edema, remain unclear. To determine whether isolated SRL induces proteinuria or not, the authors intraperitoneally injected C57BL/6 mice with different doses of SRL (0 mg/[kg·d], 3 mg/[kg·d], 10 mg/[kg·d], or 30 mg/[kg·d]) for 24 days. Urinary albumin excretion was then quantified using a double-sandwich enzyme-linked immunosorbent assay, and serum creatinine levels were measured using a single dry-film chemistry auto-analyzer. The mRNA expression levels of various genes were also measured by polymerase chain reaction. Urinary albumin was not detected in the SRL-treated mice, but serum creatinine levels were found to increase dose-dependently and were significantly higher in the animals treated with 30 mg/kg of SRL than in untreated controls. Glomerular mRNA expression profiling showed down-regulations of podocyte-related genes (Wilms tumor 1, synaptopodin, nephrin, CD2-associated protein, and podocin) and of transforming growth factor-beta (a marker of fibrosis) in sirolimus-treated mice. In addition, expressions of the antiapoptotic genes Bcl-2 and Bcl-xL were also down-regulated. Furthermore, the protein levels of these genes in mice kidney were also decreased by sirolimus. Although sirolimus treatment reduced the expressions of slit diaphragm-associated molecules and increased serum creatinine levels, it failed to induce proteinuria. Our findings indicate that proteinuria is not induced by isolated SRL treatment. Further studies are required to identify conditions in which sirolimus induces proteinuria.

Rituximab and hepatitis B reactivation in HBsAg-negative/ anti-HBc-positive kidney transplant recipients

Background

Hepatitis B virus (HBV) reactivation is a well-known complication of immunosuppressive therapy. Although rituximab is increasingly used for desensitization of ABO-incompatible or positive crossmatch kidney transplantation, the risk of HBV reactivation in hepatitis B surface antigen (HBsAg)-negative/hepatitis B core antibody (anti-HBc)-positive kidney transplant patients receiving rituximab desensitization remains undetermined.

Methods

We analysed 172 resolved HBV patients who underwent living donor kidney transplantation between 2008 and 2014. Patients were divided into rituximab ( n  =  49) or control ( n  =  123) groups. All patients were observed for HBV reactivation, which was defined as the reappearance of hepatitis B surface antigen or HBV DNA.

Results

During the follow-up period (median, 58 months; range, 4-95 months), five patients (10.2%) in the rituximab group and two patients (1.6%) in the control group experienced HBV reactivation (P   =   0.003). In the rituximab group, two patients experienced HBV-related severe hepatitis, and one patient died due to hepatic failure. The median time from rituximab desensitization to HBV reactivation was 11 months (range, 5-22 months). By contrast, no patients in the control group experienced severe hepatitis. The status of hepatitis B surface antibody was similar between groups. Rituximab desensitization [hazard ratio (HR), 9.18; 95% confidence interval (CI), 1.74-48.86; P   =   0.009] and hepatitis B surface antibody status (HR, 4.74; 95% CI, 1.05-21.23, P =   0.04) were significant risk factors for HBV reactivation.

Conclusions

Rituximab desensitization for incompatible kidney transplantation significantly increased the risk of HBV reactivation in HBsAg-negative/anti-HBc-positive patients. Therefore, close monitoring of HBV DNA is required in these patients.

Impact of the Ratio of Visceral to Subcutaneous Adipose Tissue in Donor Nephrectomy Patients

OBJECTIVE

It was reported that a metabolic syndrome affected the remaining renal function after living donor nephrectomy. However, the measurement of waist circumference is unclear because it cannot distinguish between visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). We investigate the clinical correlation between body adipose tissue and renal function recovery after living donor nephrectomy.

METHODS

From July 2013 to February 2015, 75 living kidney donors were enrolled. The VAT and SAT were measured by preoperative computed tomography (CT) scan. Body mass index (BMI), VAT, SAT, and VAT-to-SAT ratio were analyzed according to a postoperative renal function recovery. Receiver operating characteristic (ROC) was performed to predict estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m² at postoperative 6 months for BMI, VAT, SAT, and VAT-to-SAT ratio.

RESULTS

The lowest value of eGFR (57.52 ± 11.20 mL/min/1.73 m²) was measured at postoperative day 7. There was no statistically significant difference in eGFR between 1 month and 3 months. BMI, VAT, SAT, and VAT-to-SAT ratio showed a statistically significant correlation with each other (Pearson correlation, P < .05). Also, the recovery time of eGFR was correlated with VAT-to-SAT ratio; it was significant at postoperative 1, 3, and 6 months. VAT-to-SAT ratio (0.654, 95% confidence interval 0.525-0.783, P = .024) had higher predictive value in ROC.

CONCLUSION

We developed a new variable to predict the value of lower eGFR (less than 60 mL/min/1.73 m²) at a postoperative 6 months in living kidney donor. According to a CT scan, VAT-to-SAT ratio can predict renal function recovery.

Risk factors for Pneumocystis jirovecii pneumonia (PJP) in kidney transplantation recipients

Pneumocystis jirovecii pneumonia (PJP) is a potentially life-threatening infection that occurs in immunocompromised patients. The aim of this study was to evaluate risk factors for PJP in kidney transplantation recipients. We conducted a retrospective analysis of patient data from 500 consecutive kidney transplants performed at Severance Hospital between April 2011 and April 2014. Eighteen kidney transplantation recipients (3.6%) were diagnosed with PJP. In the univariate analysis, acute graft rejection, CMV infection, use of medication for diabetes mellitus, and lowest lymphocyte count were associated with PJP. Recipients who experienced acute graft rejection (odds ratio [OR] 11.81, 95% confidence interval [CI] 3.06–45.57, P < 0.001) or developed CMV infection (OR 5.42, 95% CI 1.69–17.39, P = 0.005) had high odds of PJP in multivariate analysis. In the acute graft rejection subgroup, patients treated with anti-thymocyte globulin (ATG) had significantly higher odds of PJP (OR 5.25, 95% CI 1.01–27.36, P = 0.006) than those who were not. Our data suggest that acute graft rejection and CMV infection may be risk factors for PJP in kidney transplant patients. The use of ATG for acute graft rejection may increase the risk of PJP.

Plasma Neutrophil Gelatinase-associated Lipoprotein in Living Kidney Donors

BACKGROUND

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker for acute kidney injury. This study was conducted to determine the clinical implications of perioperative plasma NGAL levels for renal function after living donor nephrectomy.

METHODS

Between July 2013 and May 2014, 112 donors underwent live donor nephrectomy at our institution. Donor plasma NGAL levels were measured perioperatively for 6 months. The relationship between perioperative plasma NGAL and recovery of renal function was analyzed. Renal function was estimated with the Modification of Diet in Renal Disease formula.

RESULTS

Mean preoperative NGAL was 62.1 ± 29.5 ng/mL. Plasma NGAL was most elevated 1 week postoperatively (218 ± 95.5 ng/mL), and stabilized after 1 month (122.9 ± 45.3 ng/mL). Preoperative plasma NGAL was not correlated with donor age or preoperative estimated glomerular filtration rates (eGFR), but was negatively correlated with 6-month eGFR (r = -0.458, P < .001). During the observation period, plasma NGAL at 1 week was most correlated with 6-month eGFR (r = -0.554, P < .001). An ROC curve analysis showed that age, preoperative eGFR, and 1-week postoperative plasma NGAL were highly predictive of developing of chronic kidney disease (CKD), defined as eGFR <60 mL/min/1.73 m(2), 6 months postoperatively (AUC = 0.91, P < .001). One-week postoperative plasma NGAL was also independently associated with CKD risk at 6 months (odds ratio: 1.13 for each 10 ng/mL increase, P = .013).

CONCLUSION

Plasma NGAL becomes elevated after kidney donation and can provide information about acute kidney injury during the compensatory hyperfiltration period. Donors with increased perioperative plasma NGAL require close observation because their possibility of developing CKD after donation may be greater.

Health-Related Quality of Life of Kidney Transplantation Patients: Results from the KoreaN Cohort Study for Outcome in Patients With Kidney Transplantation (KNOW-KT) Study

BACKGROUND

As patient and graft survival rates have been improving after kidney transplantation, health-related quality of life (HR-QOL) has become an important indicator of effective treatment. This study aimed to evaluate changes in HR-QOL after kidney transplantation.

MATERIALS AND METHODS

The KoreaN cohort study for Outcome in patients With Kidney Transplantation (KNOW-KT) is a multicenter, observational, 9-year, cohort study. The HR-QOL of patients in the KNOW-KT study was assessed before transplantation and 2 years after transplantation using the Kidney Disease Quality of Life Short Form (KDQOL-SF) including chronic kidney disease targeted area and the Medical Outcome Study 36-item Short Form Health Survey (SF-36). Multivariate linear regression was used to identify significant factors associated with follow-up QOL scores.

RESULTS

A total of 175 patients from 8 centers were analyzed. All QOL scores including the total QOL score, chronic kidney disease targeted score, and SF-36 at the 2-year follow-up were significantly increased compared to baseline values. Both physical and mental scale scores were improved after transplantation.

CONCLUSION

The QOL scores for both the mental and physical scales were improved at 2 years after kidney transplantation. High glomerular filtration rate at 2 years, high baseline QOL score, and low body mass index were associated with good follow-up QOL scores. Kidney transplantation for an Asian population with end-stage renal disease can result in better QOL as well as better patient and graft survival.

Variability of the Estimated Glomerular Filtration Rate in the First Year after Kidney Transplantation Is an Independent Risk Factor for Poor Renal Allograft Outcomes: A Retrospective Cohort Study

Renal function in the first year after kidney transplantation (KT) can predict long-term renal graft survival. This study investigated whether estimated glomerular filtration rate (eGFR) variability during the first year after KT is a risk factor for poor renal allograft outcomes. This retrospective cohort study included 3077 patients who underwent repeated eGFR measurements for 1 year after KT at Severance Hospital Transplantation Center between 1979 and 2012. The eGFR variability during the first year after KT was the predictor. The patients were divided into four quartile groups of eGFR variability according to the coefficient of variation for eGFR (eGFR-CV). We selected a cutoff of eGFR-CV for graft failure and performed the sensitivity analyses. The graft outcome was worse in the highest quartile group of eGFR variability than in the other groups among all patients (Q4: HR 1.631, 95% CI 1.278-2.081; p < 0.0001) and among patients without AR (Q4: HR 1.425, 95% CI 1.024-1.982; p = 0.0358) after adjusting for eGFR at 1 year after KT and other covariates. Additionally, all-cause mortality was higher in this highest quartile group than in the other groups among all patients but not among patients without AR. Higher eGFR-CVs than the cutoff were significantly associated with a high risk of graft failure among all patients (HR 1.670, 95% CI 1.395-2.000; p < 0.0001) and among patients without AR (HR 1.899, 95% CI 1.457-2.477; p < 0.0001) after fully adjusting for covariates. For all-cause mortality, a higher eGFR-CV was an independent risk factor among all patients but not among patients without AR after adjusting for covariates. eGFR variability in the first year after KT is an independent risk factor for poor renal allograft outcomes.

Low Adherence to Immunosuppressants Is Associated With Symptom Experience Among Kidney Transplant Recipients

PURPOSE

The purpose of this study was to investigate the relationship between immunosuppressant-related symptom experience (SE) and adherence to immunosuppressant regimens among kidney transplant (KT) recipients.

METHODS

A total of 239 KT recipients on an immunosuppressant regimen who were followed up after transplantation participated in this study. Data was collected through a self-reported questionnaire survey (medication adherence, SE, and quality of life) and medical record review.

RESULTS

Low adherence in the immunosuppressant group was associated with longer time since KT, less comorbidity (<3), and a higher rehospitalization rate. Low adherence among KT recipients showed significantly greater overall symptom occurrence (P = .001) and symptom distress (P = .002) levels than patients with high or medium adherence after adjusting for a number of covariates. The most common symptom both in terms of occurrence (96.4%) and distress (91.1%) among poorly adherent KT recipients was tiredness.

CONCLUSION

Low adherence to an immunosuppressant regimen was significantly associated with high SE among KT recipients. Strategies to decrease immunosuppressant-related SE are needed to improve adherence to immunosuppressants.

Induced regulatory T cells in allograft tolerance via transient mixed chimerism

Successful induction of allograft tolerance has been achieved in nonhuman primates (NHPs) and humans via induction of transient hematopoietic chimerism. Since allograft tolerance was achieved in these recipients without durable chimerism, peripheral mechanisms are postulated to play a major role. Here, we report our studies of T cell immunity in NHP recipients that achieved long-term tolerance versus those that rejected the allograft (AR). All kidney, heart, and lung transplant recipients underwent simultaneous or delayed donor bone marrow transplantation (DBMT) following conditioning with a nonmyeloablative regimen. After DBMT, mixed lymphocyte culture with CFSE consistently revealed donor-specific loss of CD8⁺ T cell responses in tolerant (TOL) recipients, while marked CD4⁺ T cell proliferation in response to donor antigens was found to persist. Interestingly, a significant proportion of the proliferated CD4⁺ cells were FOXP3⁺ in TOL recipients, but not in AR or naive NHPs. In TOL recipients, CD4⁺FOXP3⁺ cell proliferation against donor antigens was greater than that observed against third-party antigens. Finally, the expanded Tregs appeared to be induced Tregs (iTregs) that were converted from non-Tregs. These data provide support for the hypothesis that specific induction of iTregs by donor antigens is key to long-term allograft tolerance induced by transient mixed chimerism.

Comparative Proteomic Analysis of Rapamycin Versus Cyclosporine Combination Treatment in Mouse Podocytes

BACKGROUND

The mechanism of podocyte injury observed with the use of rapamycin (RPM) remains unclear. The conversion from calcineurin inhibitors (CNIs) to RPM in kidney transplant recipients has been associated with a higher incidence of proteinuria and renal injury. In this study, we performed proteomic analyses to investigate the alteration of protein expression in mouse podocytes treated with RPM in comparison with CNI/RPM combination.

METHODS

Immortalized mouse podocytes were treated with 20 nmol/L RPM or 20 nmol/L RPM + 1 μg/mL cyclosporine. Podocyte proteins were separated by 2-dimensional polyacrylamide gel electrophoresis (2DE) and identified by matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry and peptide fingerprinting. Selected proteins were analyzed by means of Western blot assay.

RESULTS

We identified 36 differently expressed proteins after isolated RPM or CNI/RPM combination treatment in cultured mouse podocytes. There are 3 distinct patterns of protein expression: (1) potentiated down- or upregulation of proteins by CNI/RPM treatment compared with isolated RPM treatment (n = 4); (2) partial offset of down-regulation by CNI/RPM in comparison with RPM treatment (n = 25); (3) no difference in down-regulation between RPM and CNI/RPM treatment (n = 5). We found a significant interplay between RPM and CNI on the expression of the selected proteins in mouse podocytes. This might explain the higher incidence of proteinuria by CNI/RPM combination in clinical settings.

CONCLUSIONS

Further study is required to elucidate the target protein associated with RPM-induced podocyte injury.

Concurrent Post-Transplantation Diabetes Mellitus in Renal Allograft Recipients With Immunoglobulin A Nephropathy

BACKGROUND

The prevalence of post-transplantation immunoglobulin A nephropathy (PTIgAN) and diabetes mellitus (PTDM) increases with time after transplantation, and recognition and management of these conditions is becoming more important in renal allograft recipients as graft survival increases.

METHODS

We explored the influence of concurrent PTDM on renal allograft histology and function in 111 cases with PTIgAN diagnosed from 2000 to 2010 at our institution.

RESULTS

Sixteen patients (14.4%) had PTDM at the time of diagnosis of PTIgAN, which increased to 28 patients (25.2%) at the last follow-up (10.4 years after transplantation). Donor ages were younger in PTIgAN patients with concurrent PTDM. However, other clinical and demographic data were not significantly different between PTIgAN patients with and without PTDM. Histologically, Banff "mm" scores were higher and "M1" of the Oxford classification was more frequent in PTIgAN patients with concurrent PTDM than in patients without PTDM, but the difference did not reach statistical significance. Serum creatinine levels and proteinuria at the time of biopsy and overall graft survival did not vary according to the presence of PTDM both at biopsy and at the last follow-up.

CONCLUSIONS

Concurrent PTDM does not significantly influence graft function or outcome for 10 years after transplantation in PTIgAN patients.

Predictive Value of Echocardiographic Abnormalities and the Impact of Diastolic Dysfunction on In-hospital Major Cardiovascular Complications after Living Donor Kidney Transplantation

Patients with end-stage renal disease (ESRD) show characteristic abnormalities in cardiac structure and function. We evaluated the influence of these abnormalities on adverse cardiopulmonary outcomes after living donor kidney transplantation in patients with valid preoperative transthoracic echocardiographic evaluation. We then observed any development of major postoperative cardiovascular complications and pulmonary edema until hospital discharge. In-hospital major cardiovascular complications were defined as acute myocardial infarction, ventricular fibrillation/tachycardia, cardiogenic shock, newly-onset atrial fibrillation, clinical pulmonary edema requiring endotracheal intubation or dialysis. Among the 242 ESRD study patients, 9 patients (4%) developed major cardiovascular complications, and 39 patients (16%) developed pulmonary edema. Diabetes, ischemia-reperfusion time, left ventricular end-diastolic diameter (LVEDd), left ventricular mass index (LVMI), right ventricular systolic pressure (RVSP), left atrium volume index (LAVI), and high E/E' ratios were risk factors of major cardiovascular complications, while age, LVEDd, LVMI, LAVI, and high E/E' ratios were risk factors of pulmonary edema. The optimal E/E' cut-off value for predicting major cardiovascular complications was 13.0, showing 77.8% sensitivity and 78.5% specificity. Thus, the patient's E/E' ratio is useful for predicting in-hospital major cardiovascular complications after kidney transplantation. We recommend that goal-directed therapy employing E/E' ratio be enacted in kidney recipients with baseline diastolic dysfunction to avert postoperative morbidity. (http://Clinical Trials.gov number: NCT02322567).

The Effect of Bortezomib on Antibody-Mediated Rejection after Kidney Transplantation

PURPOSE

Recently, bortezomib has been used to treat antibody-mediated rejection (AMR) refractory to conventional treatment such as plasmapheresis, intravenous immunoglobulin, and rituximab. The authors aimed to describe their experiences when bortezomib was used to treat refractory AMR.

MATERIALS AND METHODS

Eleven refractory AMR episodes treated with bortezomib were included in this study. The patients received one or two cycles of bortezomib (1.3 mg/m²) on days 1, 4, 8, and 11.

RESULTS

Bortezomib effectively reduced antibodies against various targets, including human leukocyte antigen (HLA) class I and II, ABO blood group antigen, and angiotensin II type 1 receptor. Antibodies were depleted or reduced significantly in eight AMR episodes. Overall, there was a significant improvement in the mean estimated glomerular filtration rate (eGFR) at 3 months after therapy (36.91±22.15 mL/min/1.73 m²) versus eGFR at time of AMR diagnosis (17.00±9.25 mL/min/1.73 m²; p=0.007). All six early-onset AMR episodes (within 6 months post-transplantation) showed full recovery of allograft function. Additionally, three of the five late-onset AMR episodes (>6 months post-transplantation) showed improved allograft function.

CONCLUSION

Anti-humoral treatment based on bortezomib might be an effective strategy against refractory AMR caused by various types of antibodies. Notably, this treatment could be more effective in early-onset AMR than in late-onset AMR.