Cumulative smoking dose is associated with subclinical renal injury: a pathological study in individuals without chronic kidney disease.

BACKGROUND: Epidemiological studies have identified smoking as an independent risk factor for development of chronic kidney disease. However, the early renal pathological lesions have not been clearly elucidated. METHODS: We investigated time-zero biopsy specimens from 547 living kidney donors and evaluated the relationships between smoking and renal histological changes, including arteriolar hyalinization, intimal thickening of small-medium arteries, global glomerulosclerosis, and interstitial fibrosis and tubular atrophy (IF/TA). RESULTS: A total of 199 subjects (36.4%) had smoking history; 92 (16.8%) and 107 (19.6%) subjects had <20 pack-years and ≥20 pack-years of smoking, respectively. Cumulative smoking dose was significantly associated with prevalence of arteriolar hyalinization: the multivariable-adjusted odds ratio (OR) per 20 pack-year increase was 1.50 (95% confidence interval 1.15-1.97). The ORs for smokers with <20 pack-years and ≥20 pack-years versus never-smokers were 1.76 (1.01-3.09) and 2.56 (1.48-4.44), respectively. Smoking was also associated with prevalence of >10% global glomerulosclerosis: the OR per 20 pack-year increase was 1.24 (0.96-1.59). The ORs for smokers with <20 pack-years and ≥20 pack-years versus never-smokers were 1.50 (0.98-2.78) and 2.11 (1.18-3.79), respectively. The ORs for these pathological changes increased significantly depending on cumulative smoking dose. Intimal thickening of small-medium arteries and IF/TA were not associated with smoking status. The prevalence of arteriolar hyalinization remained higher in patients with ≥10 years since smoking cessation than in never-smokers [OR 2.23 (1.03-4.83)]. CONCLUSIONS: Subclinical pathological injury caused by smoking is potentially associated with renal arteriolar hyalinization and glomerular ischaemia.

Development and Validation of A Liquid Chromatography-Tandem Mass Spectrometry Method to Simultaneously Measure Tacrolimus and Everolimus Concentrations in Kidney Allograft Biopsies After Kidney Transplantation.

BACKGROUND: Therapeutic drug monitoring is necessary for immunosuppressive therapy with tacrolimus and everolimus after kidney transplantation. Several studies have suggested that the concentrations of immunosuppressive agents in allografts may better reflect clinical outcomes than whole blood concentrations. This study aimed to develop a method for the simultaneous quantification of tacrolimus and everolimus concentrations in clinical biopsy samples and investigate their correlation with histopathological findings in kidney transplant recipients. METHODS: Fourteen biopsy samples were obtained from kidney transplant recipients at 3 months after transplantation. Kidney allograft concentrations (Ctissue) of tacrolimus and everolimus were measured by liquid chromatography-tandem mass spectrometry, and the corresponding whole blood trough concentrations (C0) were obtained from clinical records. RESULTS: The developed method was validated over a concentration range of 0.02-2.0 ng/mL for tacrolimus and 0.04-4.0 ng/mL for everolimus in kidney tissue homogenate. The Ctissue of tacrolimus and everolimus in kidney biopsies ranged from 21.0 to 86.7 pg/mg tissue and 33.5-105.0 pg/mg tissue, respectively. Dose-adjusted Ctissue of tacrolimus and everolimus was significantly correlated with the dose-adjusted C0 (P < 0.0001 and P = 0.0479, respectively). No significant association was observed between the Ctissue of tacrolimus and everolimus and the histopathologic outcomes at 3 months after transplantation. CONCLUSIONS: This method could support further investigation of the clinical relevance of tacrolimus and everolimus allograft concentrations after kidney transplantation.

Current antihypertensive treatment and treatment-resistant hypertension in Japanese patients with chronic kidney disease.

BACKGROUND: Hypertension is an important prognostic predictor in patients with chronic kidney disease (CKD), and the recommended target blood pressure has been continuously revised. This study aimed to reveal the current antihypertensive practices in Japanese patients with CKD. METHODS: In the Fukuoka Kidney disease Registry, we extracted 3664 non-dialysis-dependent patients with CKD. Apparent treatment-resistant hypertension (aTRH) was defined as a failure of blood-pressure control treated with three antihypertensive medication classes or a treatment with ≥ 4 classes regardless of blood pressure. The blood-pressure control complied with the target blood pressure recommended by the KDIGO 2012 guideline. RESULTS: The median age of the patients was 67 years, body mass index (BMI) was 23 kg/m2, and estimated glomerular filtration rate (eGFR) was 40 mL/min/1.73 m2. The number of patients with unachieved blood-pressure control was 1933, of whom 26% received ≥ 3 classes of antihypertensive medications. The first choice of medication was renin-angiotensin system inhibitors, followed by calcium-channel blockers. The rate of thiazide use was low in all CKD stages (3-11%). The prevalence of aTRH was 16%, which was significantly associated with BMI (odds ratio [95% confidence interval] per 1-standard deviation change, 1.38 [1.25-1.53]), decreased eGFR (1.87 [1.57-2.23]), as well as age, diabetes mellitus, and chronic heart disease. CONCLUSIONS: Renal dysfunction and obesity are important risk factors of aTRH. Even under nephrologist care, most patients were treated with insufficient antihypertensive medications. It is important to prescribe sufficient classes of antihypertensive medications, including diuretics, and to improve patients' lifestyle habits.

Treatment of chronic active T cell-mediated rejection after kidney transplantation: A retrospective cohort study of 37 transplants.

AIM: Data on the treatment of chronic active T cell-mediated rejection (CA-TCMR) are scarce, and therapeutical strategies for CA-TCMR have not been established. We retrospectively evaluated the outcomes and effects of treatment on pathological and clinical findings in patients with CA-TCMR. METHODS: This study comprised 37 patients who underwent kidney transplantation at our institute who were diagnosed with CA-TCMR between January 2018 and December 2020. Patients were followed until October 2021. RESULTS: A total of 32 of the 37 patients were treated. During the observation period, two patients died (5%), and five patients developed allograft loss (13%). A univariate Cox proportional hazards model showed that indication biopsy, higher spot urine protein/creatinine ratio (UPCR) and Banff ci/ct scores were risk factors for allograft loss. Of the treated patients, 23 underwent follow-up biopsies. The Wilcoxon signed-rank test showed significant improvement in the Baff scores for "ti", "i-IFTA", "t" and "t-IFTA" after treatment. On pathology, 13 (57%) of the patients who underwent follow-up biopsy improved to "no evidence of rejection" or "borderline change." Assuming that improvement in pathology to "borderline change" or "no evidence of rejection" on follow-up biopsy indicates response to treatment, multivariate logistic analysis showed that lower UPCR was a predictive factor for response to treatment. No specific effect of treatment type was observed. CONCLUSIONS: Our results indicate that treatment could improve the pathological findings in CA-TCMR.

Significance of revised criteria for chronic active T cell-mediated rejection in the 2017 Banff classification: Surveillance by 1-year protocol biopsies for kidney transplantation.

Diagnostic criteria for chronic active T cell-mediated rejection (CA-TCMR) were revised in the Banff 2017 consensus, but it is unknown whether the new criteria predict graft prognosis of kidney transplantation. We enrolled 406 kidney allograft recipients who underwent a 1-year protocol biopsy (PB) and investigated the diagnostic significance of Banff 2017. Interobserver reproducibility of the 3 diagnosticians showed a substantial agreement rate of 0.68 in Fleiss's kappa coefficient. Thirty-three patients (8%) were classified as CA-TCMR according to Banff 2017, and 6 were previously diagnosed as normal, 12 as acute TCMR, 10 with borderline changes, and 5 as CA-TCMR according to Banff 2015 criteria. Determinant factors of CA-TCMR were cyclosporine use (vs tacrolimus), previous acute rejection, and BK polyomavirus-associated nephropathy. In survival analysis, the new diagnosis of CA-TCMR predicted a composite graft endpoint defined as doubling serum creatinine or death-censored graft loss (log-rank test, P < .001). In multivariate analysis, CA-TCMR was associated with the second highest risk of the composite endpoint (hazard ratio: 5.42; 95% confidence interval, 2.02-14.61; P < .001 vs normal) behind antibody-mediated rejection. In conclusion, diagnosis of CA-TCMR in Banff 2017 may facilitate detecting an unfavorable prognosis of kidney allograft recipients who undergo a 1-year PB.

Development and validation of a risk score for the prediction of cardiovascular disease in living donor kidney transplant recipients.

BACKGROUND: Cardiovascular disease (CVD) is a major cause of death in kidney transplant (KT) recipients. To improve their long-term survival, it is clinically important to estimate the risk of CVD after living donor KT via adequate pre-transplant CVD screening. METHODS: A derivation cohort containing 331 KT recipients underwent living donor KT at Kyushu University Hospital from January 2006 to December 2012. A prediction model was retrospectively developed and risk scores were investigated via a Cox proportional hazards regression model. The discrimination and calibration capacities of the prediction model were estimated via the c-statistic and the Hosmer-Lemeshow goodness of fit test. External validation was estimated via the same statistical methods by applying the model to a validation cohort of 300 KT recipients who underwent living donor KT at Tokyo Women's Medical University Hospital. RESULTS: In the derivation cohort, 28 patients (8.5%) had CVD events during the observation period. Recipient age, CVD history, diabetic nephropathy, dialysis vintage, serum albumin and proteinuria at 12 months after KT were significant predictors of CVD. A prediction model consisting of integer risk scores demonstrated good discrimination (c-statistic 0.88) and goodness of fit (Hosmer-Lemeshow test P = 0.18). In a validation cohort, the model demonstrated moderate discrimination (c-statistic 0.77) and goodness of fit (Hosmer-Lemeshow test P = 0.15), suggesting external validity. CONCLUSIONS: The above-described simple model for predicting CVD after living donor KT was accurate and useful in clinical situations.

Stronger Effect of Azilsartan on Reduction of Proteinuria Compared to Candesartan in Patients with CKD: A Randomized Crossover Trial.

INTRODUCTION: Angiotensin receptor blockers (ARBs) are preferably used in hypertensive patients with CKD. Azilsartan is a strong antihypertensive ARB, but its antiproteinuric effects are not well understood. We compared the antiproteinuric effect of azilsartan and candesartan in CKD patients in an open-label, randomized, crossover trial. METHODS: A total of 111 patients were treated with 20 mg of azilsartan daily for 2 months as a run-in period. After the run-in period, patients were randomized into 2 arms and received either 20 mg of azilsartan or 8 mg of candesartan daily for 3 months in a crossover trial. The primary outcome was the percent change in urinary protein-to-Cr ratio (UPCR). RESULTS: Ninety-five patients completed the trial. The mean age was 64.3 years. The estimated glomerular filtration rate (eGFR) and UPCR were 41.5 mL/min/1.73 m2 and 1.8 g/gCr, respectively. The baseline systolic and diastolic blood pressures were 131.4 and 71.0 mm Hg, respectively. The mean percent change in the UPCR was -3.8% in the azilsartan group and 30.8% in the candesartan group at the 1st endpoint (p = 0.0004), and 6.1% in the azilsartan group and 25.8% in the candesartan group at the 2nd (final) endpoint (p = 0.029). The incidence of adverse events, including eGFR levels and serum potassium levels, was not significantly different between the groups. CONCLUSION: A 20 mg azilsartan dose had potent antiproteinuric effects compared with an 8 mg candesartan dose, without an increase in adverse events. Azilsartan may provide renal protection in addition to antihypertensive effects in CKD patients.

Non-invasive fibrosis assessments of non-alcoholic fatty liver disease associated with low estimated glomerular filtration rate among CKD patients: the Fukuoka Kidney disease Registry Study.

BACKGROUND: A growing body of evidence has shown that non-alcoholic fatty liver disease (NAFLD) is associated with chronic kidney disease (CKD). Non-invasive fibrosis assessments of NAFLD such as Fibrosis-4 (FIB-4) index and NAFLD fibrosis score (NFS) have been developed to substitute liver biopsy. Little is known about the association between FIB-4 index or NFS and the components of CKD. METHODS: In the present cross-sectional study, we assessed of 3640 Japanese CKD patients. We examined the association between FIB-4index or NFS and the odds of having low estimated glomerular filtration rate (eGFR) defined as eGFR < 60 mL/min/1.73 m2 or albuminuria defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Patients were divided into quartiles according to their baseline FIB-4 index and NFS levels. Linear and logistic regression analysis were conducted, with adjustment for potential confounding factors. RESULTS: FIB-4 index and NFS were negatively associated with eGFR, but not UACR, after adjustment for potential confounding factors. Both FIB-4 index and NFS were significantly associated with low eGFR after adjustment for potential confounding factors. Meanwhile, in the multivariable-adjusted model, no associations were found between FIB-4 index or NFS and albuminuria. The addition of FIB-4 index or NFS to the established clinical CKD risk factors improved diagnostic accuracy of prevalence of low eGFR. We also found that there was a significant trend of higher FIB-4 index and NFS with more advanced renal fibrosis using the kidney biopsy data. CONCLUSIONS: Higher non-invasive fibrosis assessments of NAFLD were associated with higher odds of decreased eGFR.

Evaluation of postoperative kidney function after administration of 6% hydroxyethyl starch during living-donor nephrectomy for transplantation.

PURPOSE: We aimed to investigate whether 6% HES 130/0.4 was associated with postoperative reduction of estimated glomerular filtration rate (eGFR) in donor patients who underwent nephrectomy for living kidney transplantation. METHODS: This retrospective study included 213 living kidney transplant donors treated at Kyushu University Hospital in Japan from April 2014 to March 2018. Patients who were administered 6% HES 130/0.4 were allocated in the HES group (n = 108), and those who were not were allocated in the control group (n = 105). The postoperative decrements in estimated glomerular filtration rates (eGFRs) from preoperative values were calculated on postoperative days (PODs) 1, 3, and 14. Decline in kidney function (DKF) according to the Kidney Disease: Improving Global Outcomes (KDIGO) classification were analyzed by multivariable-adjusted ordinal logistic regression to estimate odds ratios (ORs) for postoperative DKF. RESULTS: In HES group, administration amount of HES was median 9.4 [interquartile range: 8.2-14.3] ml/kg. Postoperative decrements in eGFR were similar in the control and HES groups on POD 1 (control group: mean 32.0 vs. HES group: 33.0 mL/min/1.73 m2), same as POD 3 (21.1 vs. 22.4 mL/min/1.73 m2) and POD 14 (26.0 vs. 25.9 mL/min/1.73 m2), even after adjusting for confounding factors. The multivariable-adjusted ORs for postoperative DKF did not significantly increase in the HES group on POD 1 (OR: 0.88), POD 3 (OR: 0.96), and POD 14 (OR: 0.52) compared with the control group. CONCLUSION: Six percent HES 130/0.4 is not associated with postoperative renal dysfunction in donor patients undergoing nephrectomy for kidney transplantation.

Utility of Columbia classification in focal segmental glomerulosclerosis: renal prognosis and treatment response among the pathological variants.

BACKGROUND: The utility of the Columbia classification (Col-class) for focal segmental glomerulosclerosis (FSGS) has not yet been fully proven. METHODS: We extracted 201 FSGS patients from 10 nephrology centers in Japan and investigated the difference of a composite renal endpoint, defined as doubling of serum creatinine and/or development of end-stage renal disease, in pathological variants. Sensitivity analysis was used to prove the utility of the Col-class to predict renal outcomes. Additionally, the renal protective effects of steroids and/or immunosuppression (steroid/IS) were investigated in patients stratified according to the Col-class. RESULTS: The patients were classified into the following variants: not otherwise specified [NOS; n = 121 (60.1%)], perihilar [n = 31 (15.4%)], cellular [n = 19 (9.5%)], tip [n = 17 (8.5%)] and collapsing [n = 13 (6.5%)]. No tip variant patients reached the renal endpoint. The renal outcome in the collapsing variant was significantly poorer than that in the NOS [hazard ratio (HR) 3.71; P = 0.005]. In the sensitivity analysis, the area under the receiver operating characteristic curve for the renal endpoint was increased by adding Col-class to a model including common risk factors (P = 0.021). In a subgroup treated without steroid/IS, the outcome in the cellular variant was worse than that in the NOS (HR 5.10; P = 0.040) but the difference was not observed in the subgroup with steroid/IS (HR 0.54; P = 0.539). CONCLUSIONS: The Col-class is useful to predict renal prognosis in Japanese patients with FSGS. In addition to good prognosis in the tip variant and poor in the collapsing variant, good clinical course in the cellular variant treated with steroid/IS was suggested.

Estimated plasma osmolarity and risk of end-stage kidney disease in patients with IgA nephropathy.

BACKGROUND: Several experimental studies have indicated that increased plasma osmolarity caused by recurrent dehydration is involved in kidney injury via a mechanism, mediated by vasopressin secretion and activation of the aldose reductase pathway. Epidemiologic evidence linking increased plasma osmolarity and the onset of end-stage kidney disease (ESKD), in patients with primary glomerulonephritis, is lacking. METHODS: We retrospectively examined 663 patients with IgA nephropathy (IgAN) diagnosed by kidney biopsy and evaluated the association between estimated plasma osmolarity and ESKD prevalence, using a Cox proportional hazards model. RESULTS: During follow-up (median 80.4 months; interquartile range 22.2-120.1), 73 patients developed ESKD. In a baseline survey, plasma osmolarity was correlated negatively with the mean value of the estimated glomerular filtration rate, but correlated positively with the mean value of urinary protein excretion, systolic blood pressure, and pathologic severity of extracapillary proliferation, in addition to tissue fibrosis and sclerosis. The incidence rate of ESKD increased linearly with increase in plasma osmolarity (P < 0.05 for trend). In multivariate analyses, plasma osmolarity was an independent risk factor for ESKD (hazard ratio for each increment of 5 mOsm/kg in plasma osmolarity 1.56; 95% confidence interval 1.18-2.07) even after adjustment for potential confounders. CONCLUSIONS: Increased plasma osmolarity was associated significantly with an increased risk of ESKD in patients with IgAN. Maintenance of plasma osmolarity by appropriate control of the balance between salt and water may contribute to kidney protection.

Effect of renin-angiotensin system blockade on graft survival and cardiovascular disease in kidney transplant recipients: retrospective multicenter study in Japan.

BACKGROUND: Renin-angiotensin system blockers (RASBs) reduce end-stage kidney disease and cardiovascular event (CVE) development in chronic kidney disease. However, whether RASBs improve long-term prognosis in kidney transplant (KT) recipients remain unknown. METHOD: We investigated 900 kidney transplant patients in a multicenter retrospective cohort study in Japan and compared death-censored graft survival and CVE (total, cardiac events, stroke) based on RASB use within 12 months after KT. The associations were examined using a Cox hazard model and propensity score-matching analysis. RESULTS: The cohort comprised 375 patients treated with RASBs (RASB group) and 525 patients without RASBs (control group). The median observational period was 82 months, with 68 patients reaching graft loss: 79 total CVE, 36 cardiac events, 26 stroke. In a matching cohort comprising 582 patients, death-censored graft survival, total CVE, and cardiac events were not different between the two groups. Only stroke incidence rate was significantly lower in the RASB group compared with the control group (1.4 vs. 6.4 per 1000 patients/year, log-ranked P = 0.005). In a multivariable analysis, stroke events were also significantly lower in the RASB group compared with the control group (Hazard ratio and 95% confidence interval, 0.20 [0.04-0.62]). CONCLUSION: Thus, RASBs potentially reduce stroke events in KT recipients.

Donor CYP3A5 Gene Polymorphism Alone Cannot Predict Tacrolimus Intrarenal Concentration in Renal Transplant Recipients.

CYP3A5 gene polymorphism in recipients plays an important role in tacrolimus blood pharmacokinetics after renal transplantation. Even though CYP3A5 protein is expressed in renal tubular cells, little is known about the influence on the tacrolimus intrarenal exposure and hence graft outcome. The aim of our study was to investigate how the tacrolimus intrarenal concentration (Ctissue) could be predicted based on donor CYP3A5 gene polymorphism in renal transplant recipients. A total of 52 Japanese renal transplant patients receiving tacrolimus were enrolled in this study. Seventy-four renal biopsy specimens were obtained at 3 months and 1 year after transplantation to determine the donor CYP3A5 polymorphism and measure the Ctissue by liquid chromatography-tandem mass spectrometry (LC-MS-MS). The tacrolimus Ctissue ranged from 52 to 399 pg/mg tissue (n = 74) and was weak but significantly correlated with tacrolimus trough concentration (C0) at 3 months after transplantation (Spearman, r = 0.3560, p = 0.0096). No significant relationship was observed between the donor CYP3A5 gene polymorphism and Ctissue or Ctissue/C0. These data showed that the tacrolimus systemic level has an impact on tacrolimus renal accumulation after renal transplantation. However, donor CYP3A5 gene polymorphism alone cannot be used to predict tacrolimus intrarenal exposure. This study may be valuable for exploring tacrolimus renal metabolism and toxicology mechanism in renal transplant recipients.

Development and validation of a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation.

BACKGROUND: Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation. METHODS: We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m2 at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort). RESULTS: In the derivation cohort, 89 patients (25.9%) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy. CONCLUSIONS: This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

Kidney transplantation for treatment of end-stage kidney disease after haematopoietic stem cell transplantation: case series and literature review.

BACKGROUND: The safety of kidney transplantation (KT) for end-stage kidney disease (ESKD) after haematopoietic stem cell transplantation (HSCT) for haematological disease has not been investigated thoroughly. METHODS: In this retrospective multicentre study, we investigated the clinical courses of six ESKD patients that received KT after HSCT for various haematological diseases. Data for six such patients were obtained from three institutions in our consortium. RESULTS: Two patients with chronic myeloid leukaemia, one with refractory aplastic anaemia and another one with acute lymphocytic leukaemia received bone marrow transplantation. One patients with acute lymphocytic leukaemia received umbilical cord blood transplantation, and one with mantle cell lymphoma received peripheral blood stem cell transplantation. The patients developed ESKD at a median of 133 months after HSCT. Two patients who received KT and HSCT from the same donor were temporarily treated with immunosuppressive drugs. The other patients received KT and HSCT from different donors and were treated with antibody induction using our standard regimens. For one patient with ABO-incompatible transplantation, we added rituximab, splenectomy, and plasmapheresis. In the observational period at a median of 51 months after KT, only one patient experienced acute T-cell-mediated rejection. Four patients underwent hospitalization because of infection and fully recovered. No patient experienced recurrence of their original haematological disease. All patients survived throughout the observational periods, and graft functions were preserved. CONCLUSIONS: Despite the high infection frequency, survival rates and graft functions were extremely good in patients compared with previous studies. Therefore, current management contributed to favourable outcomes of these patients.

Urinary Human Epididymis Secretory Protein 4 as a Useful Biomarker for Subclinical Acute Rejection Three Months after Kidney Transplantation.

Kidney transplantation is the treatment of choice for patients with advanced chronic kidney disease (CKD) and end stage renal disease (ESRD). However, acute rejection (AR) is a common complication in kidney transplantation and is associated with reduced graft survival. Current diagnosis of AR relies mainly on clinical monitoring including serum creatinine, proteinuria, and confirmation by histopathologic assessment in the biopsy specimen of graft kidney. Although an early protocol biopsy is indispensable for depicting the severity of pathologic lesions in subclinical acute rejection (subAR), it is not acceptable in some cases and cannot be performed because of its invasive nature. Therefore, we examined the detection of noninvasive biomarkers that are closely related to the pathology of subAR in protocol biopsies three months after kidney transplantation. In this study, the urinary level of microtubule-associated protein 1 light chain 3 (LC3), monocyte chemotactic protein-1 (MCP-1), liver-type fatty acid-binding protein (L-FABP), neutrophil gelatinase-associated lipocalin (NGAL), and human epididymis secretory protein 4 (HE4) were measured three months after kidney transplantation. Urine samples of 80 patients undergoing kidney transplantation between August 2014 to September 2016, were prospectively collected after three months. SubAR was observed in 11 patients (13.8%) in protocol biopsy. The urinary levels of LC3, MCP-1, NGAL, and HE4 were significantly higher in patients with subAR than in those without, while those of L-FABP did not differ between the two groups. Multivariate regression models, receiver-operating characteristics (ROC), and areas under ROC curves (AUC) were used to identify predicted values of subAR. Urinary HE4 levels were able to better identify subAR (AUC = 0.808) than the other four urinary biomarkers. In conclusion, urinary HE4 is increased in kidney transplant recipients of subAR three months after kidney transplantation, suggesting that HE4 has the potential to be used as a novel clinical biomarker for predicting subAR.

Secular trends in the incidence of end-stage renal disease and its risk factors in Japanese patients with immunoglobulin A nephropathy.

Background: There are limited data on secular trends in the incidence of end-stage renal disease (ESRD) and frequencies of its risk factors or treatment modalities in patients with immunoglobulin A nephropathy (IgAN). Methods: This study divided 1255 patients with IgAN into three groups according to the timing of renal biopsy: 1979-89 (n = 232), 1990-99 (n = 574) and 2000-10 (n = 449). The age-adjusted incidence rates, incidence rate ratios and 95% confidence intervals (CIs) for ESRD were calculated by the person-year method and compared using Poisson regression analysis. Results: A total of 63 patients (5.0%) developed ESRD. The age-adjusted incidence of ESRD decreased significantly over time, i.e. 11.5 per 1000 person-years (95% CI 5.4-24.6) in 1979-89, 6.5 per 1000 person-years (95% CI 1.0-25.2) in 1990-99 and 4.2 per 1000 person-years (95% CI 1.0-17.7) in 2000-10. The proportions of patients with preserved renal function and acute-stage inflammatory histologic changes (i.e. endocapillary hypercellularity and extracapillary proliferation) at the timing of biopsy increased over time, as did the rates of prescriptions of renin-angiotensin system blockers and corticosteroids (all P for trend <0.05). The effect of acute inflammatory histologic lesions on renal prognosis was drastically reduced over time. Conclusions: These findings suggest that early diagnosis in the acute inflammatory phase and subsequent aggressive treatment may have contributed to the significant downward trend in the incidence of ESRD in patients with IgAN over three decades.

Effect of steroid pulse therapy on post-transplant immunoglobulin A nephropathy.

AIM: Recent studies have suggested that patients with post-transplant immunoglobulin A nephropathy have poor graft survival. There is limited research on the therapeutic effectiveness for post-transplant immunoglobulin A nephropathy, especially steroid pulse therapy. The present study evaluated the efficacy of steroid pulse therapy on post-transplant immunoglobulin A nephropathy. METHODS: We retrospectively analyzed patients diagnosed with de novo or recurrent immunoglobulin A nephropathy at Kyushu University Hospital between January 2013 and August 2015. Patients with moderate proteinuria (≥0.5 g/g creatinine) and/or cellular or fibrocellular crescents on a graft biopsy were treated with steroid pulse therapy. Steroid pulse therapy was 500 mg/day for 3 days in weeks 1 and 2, followed by 20 mg of oral prednisolone that was tapered after 6 months. Patients were followed for 2 years, and the estimated glomerular filtration rate, urinary findings, and adverse events were recorded. RESULTS: Seven patients received steroid pulse therapy. The mean duration after kidney transplantation was 6.6 ± 4.7 years. After 2 years of treatment, 85.7% of patients reached complete remission of proteinuria, urinary protein excretion declined (0.82 ± 0.51 to 0.26 ± 0.22 g/g creatinine, P = 0.007), and the estimated glomerular filtration rate was maintained (48.7 ± 12.8 to 47.4 ± 14.0 mL/min per 1.73 m2 , P = 0.98). Adverse events were observed in one patient who developed herpes zoster infection. CONCLUSION: Steroid pulse therapy for post-transplant immunoglobulin A nephropathy effectively reduces proteinuria over 2 years. However, comparison of steroid pulse therapy and other regimens with a high-quality design is required.

Vascular endothelial growth factor-C ameliorates renal interstitial fibrosis through lymphangiogenesis in mouse unilateral ureteral obstruction.

Renal fibrosis is the final common pathway of chronic kidney diseases. Lymphatic vessel (LV) proliferation is found in human renal diseases and other fibrotic diseases, suggesting that lymphangiogenesis is associated with the progression or suppression of kidney diseases. However, the purpose of LV proliferation is not completely understood. We investigated the effect of vascular endothelial growth factor (VEGF)-C on lymphangiogenesis, inflammation, and fibrosis in the mouse kidney using the unilateral ureteral obstruction (UUO) model. In UUO mice, significant proliferation of LVs was accompanied by tubulointerstitial nephritis and fibrosis. We continuously administered recombinant human VEGF-C to UUO model mice using an osmotic pump (UUO+VEGF-C group). Lymphangiogenesis was significantly induced in the UUO+VEGF-C group compared with the vehicle group, despite similar numbers of capillaries in both groups. The number of infiltrating macrophages, and levels of inflammatory cytokines and transforming growth factor-ß1 were reduced in the UUO+VEGF-C group compared with the vehicle group. Renal fibrosis was consequently attenuated in the UUO+VEGF-C group. In cultured lymphatic endothelial cells, administration of VEGF-C increased the activity and proliferation of lymphatic endothelial cells (LECs) and expression of adhesion molecules such as vascular cell adhesion molecule-1. These findings suggest that induction of lymphangiogenesis ameliorates inflammation and fibrosis in the renal interstitium. Enhancement of the VEGF-C signaling pathway in LECs may be a therapeutic strategy for renal fibrosis.

Clinicopathological significance of monoclonal IgA deposition in patients with IgA nephropathy.

BACKGROUND: Clinicopathological significance of monoclonal IgA deposition and its relation to bone marrow abnormalities in IgA nephropathy (IgAN) remains unclear. METHODS: We retrospectively investigated the prevalence and clinicopathological significance of monoclonal IgA deposition in 65 patients with IgAN. Serum-free light chain ratio, and urinary Bence Jones protein were also measured. RESULTS: Thirty-nine percent of patients were men, median age was 40 and median observation period was 31 months. Five patients (Group M) showed monoclonal IgA lambda deposition and one showed monoclonal IgA kappa deposition. Fifty-nine patients (Group P) showed polyclonal IgA deposition. There were no significant differences in the degree of proteinuria, hematuria and renal function between Group M and Group P. Total protein and albumin were significantly lower in Group M than in Group P. According to the Oxford classification, the percentage of patients with M1 was significantly higher in Group M than in Group P. One patient in Group P showed serum monoclonal IgG lambda. No patient showed abnormal serum-free light chain ratio. Seventy-five percent in Group M and 42 % in Group P were treated with steroid. Three patients in Group P progressed to end-stage renal disease (ESRD). The frequency of disappearance of proteinuria or hematuria and progression to ESRD was not different between the groups. CONCLUSIONS: The prevalence of monoclonal IgA deposition was 9.2 %. Although some parameters differed between the groups, renal outcome were similar. Thus, IgAN with monoclonal IgA deposition seems not to be different entity from those with polyclonal IgA deposition.