Low skeletal muscle mass index is independently associated with low bone mineral density in kidney transplant recipients: a retrospective observational cohort study.

BACKGROUND: Osteoporosis and osteopenia are more frequent in patients who have received kidney transplants than in healthy individuals. Although osteoporosis and sarcopenia are closely related, only few studies have considered them in the post-transplantation period. We aimed to investigate the relationship between lower bone mineral density and skeletal muscle in kidney transplant recipients. METHODS: We included 371 patients in the maintenance phase of kidney transplantation (> 6 months after transplantation) followed-up at our institution from January to December 2019. The primary endpoint was the association between bone mineral density and skeletal muscle mass index. As secondary endpoints, in addition to skeletal muscle mass index, we investigated other factors associated with low bone mineral density, including kidney function and 25-hydroxy vitamin D (25(OH)D) concentration. Considering the possibility that factors affecting bone mineral density differ between men and women, we explored these factors separately for both sexes. RESULTS: Of the 371 participants, 243 (65.4%) were men. The median age and time after transplantation were 52 and 14 years, respectively. Univariate analysis showed that age, female sex, time since transplantation, cystatin C-based estimated glomerular filtration rate (eGFRcysC), 25(OH)D, and skeletal muscle mass index were associated with bone mineral density. Multivariate analysis showed associations of bone mineral density with eGFRcysC, 25(OH)D, and skeletal muscle mass index. Multivariate analysis by sex showed significant associations with eGFRcysC, hemoglobin, and skeletal muscle mass index in men and with age, eGFRcysC, albumin, and skeletal muscle mass index in women. Bone mineral density was not associated with history of dialysis prior to transplantation or time since transplantation. CONCLUSIONS: In kidney transplant recipients, an independent association between lower bone mineral density and skeletal muscle mass index was observed in both sexes.

Association between Serum 25-Hydroxyvitamin D Levels and Sarcopenia in Patients Undergoing Chronic Haemodialysis.

INTRODUCTION: Sarcopenia and vitamin D deficiency are highly prevalent among patients undergoing haemodialysis. Although vitamin D deficiency, assessed using serum 25-hydroxyvitamin D (25(OH)D) levels, is known to be associated with sarcopenia in the general population, whether serum 25(OH)D levels are associated with sarcopenia in patients undergoing haemodialysis with suppressed renal activation of 25(OH)D remains unclear. This study aimed to examine the association between serum 25(OH)D levels and sarcopenia in patients undergoing haemodialysis. METHODS: Serum 25(OH)D level measurements and assessment of sarcopenia using the Asian Working Group for Sarcopenia criteria were conducted in 95 stable outpatients undergoing maintenance haemodialysis therapy. RESULTS: Sarcopenia was observed in 22 (23.1%) patients. In multiple logistic regression analysis, serum 25(OH)D levels were associated with sarcopenia (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.77-0.99, p = 0.039) independent of traditional risk factors for sarcopenia. In multiple linear regression analyses, serum 25(OH)D levels were associated with parameters of skeletal muscle mass and strength (ß = 0.145, p = 0.046, and ß = 0.194, p = 0.020, respectively). The adjusted OR for sarcopenia was 5.60 (95% CI 1.52-20.57, p = 0.009) in the vitamin D deficiency group categorized based on the cut-off serum 25(OH)D level of 10 ng/mL. Regarding model discrimination, adding vitamin D deficiency to the traditional risk factors significantly improved the integrated discrimination improvement score (0.093, p = 0.007). CONCLUSION: Lower serum 25(OH)D levels were associated with sarcopenia independent of traditional risk factors in patients undergoing haemodialysis with suppressed vitamin D activation in the kidney. This finding implies that circulating 25(OH)D may have an important relationship with the skeletal muscle function of patients undergoing haemodialysis, and its measurement may be recommended to identify patients at high risk for sarcopenia among those undergoing haemodialysis.

Impact of an angulated aorto-septal relationship on cardio-cerebrovascular outcomes in patients undergoing hemodialysis.

Aortic and valvular calcification are well-known risk factors for cardio-cerebrovascular events in patients undergoing hemodialysis. We investigated the clinical impact of an angulated aorto-septal angle as a result of aortic elongation due to aortic calcification on cardio-cerebrovascular outcomes in patients undergoing hemodialysis. We investigated 306 patients (mean age 65.4 years, 68% male) who underwent pre-scheduled routine echocardiography between April and September 2018. The angle between the anterior wall of the aorta and the ventricular septal surface (ASA) was quantified. We determined aortic and mitral valve calcification scores based on calcified cardiac changes; the aortic and mitral valve scores ranged between 0-9 and 0-6, respectively. The primary endpoint was a composite including cardio-cerebrovascular events and cardio-cerebrovascular death. The mean duration of dialysis among the patients in this analysis was 9.6 years. The primary endpoint was observed in 54 patients during the observational period (median 1095 days). Multivariable Cox proportional hazards analyses identified left ventricular ejection fraction (per 10% increase: hazard ratio [HR] 0.67; 95% confidential interval [CI] 0.53-0.84, P = 0.001), left ventricular mass index (per 10 g/m2 increase: HR 1.14; 95% CI 1.05-1.24, P = 0.001), ASA (per 10 degree increase: HR 0.69; 95% CI 0.54-0.88; P = 0.003), and aortic valve calcification score (HR 1.15; 95% CI 1.04-1.26, P = 0.005) as independent determinants of the primary endpoint. Kaplan-Meier analysis showed a higher incidence of the primary endpoint in patients with ASA <119.4 degrees than those with ASA ≥119.4 degrees (Log-rank P < 0.001). An angulated aorto-septal angle is an independent risk factor for cardio-cerebrovascular events and cardio-cerebrovascular death in patients undergoing hemodialysis.

Coexistence of Low Muscle Mass and Osteoporosis as a Predictor of Fragility Fractures in Long-Term Kidney Transplant Recipients.

INTRODUCTION: Sarcopenia and osteoporosis are highly prevalent among kidney transplant recipients (KTRs). Although osteoporosis is known to increase fracture risk in KTRs, it is unclear whether sarcopenia or osteosarcopenia is associated with this increased risk. Thus, we aimed to investigate the association of the coexistence of low muscle mass (LMM) and osteoporosis with the risk of fracture in long-term KTRs. METHODS: Exactly 342 stable KTRs underwent dual-energy X-ray absorptiometry and skeletal muscle mass index (SMI) measurement using bioelectrical impedance analysis. RESULTS: LMM and osteoporosis were observed in 109 (31.9%) and 93 patients (27.2%), respectively. During a follow-up period of 5.1 years, 48 (14.0%) fractures occurred. KTRs with LMM had a higher fracture risk, but this was not significant (adjusted hazard ratio [aHR] 1.82, 95% confidence interval [CI] 0.94-3.50, p = 0.073). Similar results were obtained in KTRs with osteoporosis (aHR 1.84, 95% CI 0.96-3.47, p = 0.063). We divided the KTRs into four groups according to the presence of LMM and/or osteoporosis. The cumulative incidence rates of fractures were 13.0%, 11.1%, 10.5%, and 31.3% in the KTRs without both LMM and osteoporosis, those with LMM alone, those with osteoporosis alone, and those with both, respectively. The KTRs with both LMM and osteoporosis had a 2.92fold higher risk of fractures (95% CI 1.29-6.49; p = 0.010) than those without both LMM and osteoporosis. CONCLUSION: Long-term KTRs with the coexistence of LMM and osteoporosis had an independently higher risk of fragility fractures than those without both LMM and osteoporosis. The combination of SMI and osteoporosis definitions can be used to identify KTRs with a high fracture risk.

The association of low serum magnesium levels with frailty among hemodialysis patients.

Frailty is common among hemodialysis patients and is associated with mortality and fractures. Hypomagnesemia is also known to be a risk factor for mortality and fractures and has been shown to be significantly associated with muscle performance indexes. However, little is known about the association between hypomagnesemia and frailty. We enrolled 339 outpatients who underwent hemodialysis and assessed frailty using the Clinical Frailty Scale (CFS), a 7-point subjective assessment tool based upon clinical judgment. We examined the association between serum magnesium levels and frailty evaluated using the CFS. The median CFS score was 3 points, and 49 (14.5%) patients had frailty (CFS score ≥ 5). In multiple regression analysis, serum magnesium levels were independently associated with increased CFS scores (ß = - 0.126, P = 0.005) adjusted for age, body mass index, diabetes, cardiovascular diseases, prevalent fractures, serum albumin and C-reactive protein. The adjusted odds ratio for frailty was 2.85 [95% confidence interval (CI) 1.23-6.97, P = 0.014] in the lower serum magnesium group categorized based on the median value. Furthermore, with regard to model discrimination, adding serum magnesium levels to the established risk factors significantly improved net reclassification (0.520, P < 0.001) and integrated discrimination (0.023, P = 0.031). Lower serum magnesium levels may be associated with the severity and definition of frailty independent of well-known risk factors.

The Impact of Liver Chemistries on Respiratory Failure among Hemodialysis Patients with COVID-19 during the Omicron Wave.

Objective Although the coronavirus disease 2019 (COVID-19) Omicron variant causes less severe symptoms than previous variants, early indicators for respiratory failure are needed in hemodialysis patients, who have a higher mortality rate than the general population. Liver chemistries are known to reflect the severity of COVID-19 in the general population. This study explored the early indicators for worsened respiratory failure based on patient characteristics, including liver chemistries. Methods This retrospective study included 117 patients admitted for COVID-19 during the Omicron wave. Respiratory failure was defined as oxygen requirement during treatment. Information on the symptoms and clinical characteristics, including liver chemistries [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], at admission was collected. Results Thirty-five patients (29.9%) required oxygen supply during treatment. In the multivariate logistic regression analyses, AST [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.00-1.13, p=0.029], ALT (OR 1.09, 95% CI 1.02-1.18, p=0.009), and moderate COVID-19 illness (Model including AST, OR 6.95, 95% CI 2.23-23.17, p<0.001; Model including ALT, OR 7.19, 95% CI 2.21-25.22, p=0.001) were independent predictors for respiratory failure. Based on the cutoff values determined by the receiver operating characteristic curve, higher AST (≥23 IU/L) and ALT levels (≥14 IU/L) were also independently associated with respiratory failure (higher AST: 64.3% vs. 18.8%, OR 3.44, 95% CI 1.08-11.10, p=0.035; higher ALT: 48.8% vs. 19.7%, OR 4.23, 95% CI 1.34-14.52, p=0.013, respectively). Conclusion The measurement of AST and ALT levels at baseline may help predict oxygen requirement in hemodialysis patients with COVID-19.

Corrigendum to "Detecting MUC1 Variants in Patients Clinicopathologically Diagnosed With Having Autosomal Dominant Tubulointerstitial Kidney Disease"Kidney International Reports, Volume 7, Issue 4, April 2022, Pages 857-866.

[This corrects the article DOI: 10.1016/j.ekir.2021.12.037.].

Non-A Blood Type Is a Risk Factor for Poor Cardio-Cerebrovascular Outcomes in Patients Undergoing Dialysis.

The clinical impact of ABO blood type on cardio-cerebrovascular outcomes in patients undergoing dialysis has not been clarified. A total of 365 hemodialysis patients participated in the current study. The primary endpoint was defined as a composite including cardio-cerebrovascular events and cardio-cerebrovascular death. The primary endpoint was observed in 73 patients during a median follow-up period of 1182 days, including 16/149 (11%) with blood type A, 22/81 (27%) with blood type B, 26/99 (26%) with blood type O, and 9/36 (25%) with blood type AB. At baseline, no difference was found in the echocardiographic parameters. Multivariable Cox regression analyses revealed that blood type (type A vs. non-A type; hazard ratio (HR): 0.46, 95% confidence interval (95% CI): 0.26-0.81, p = 0.007), age (per 10-year increase; HR: 1.47, 95% CI: 1.18-1.84), antiplatelet or anticoagulation therapy (HR: 1.91, 95% CI: 1.07-3.41), LVEF (per 10% increase; HR: 0.78, 95% CI: 0.63-0.96), and LV mass index (per 10 g/m2 increase; HR: 1.07, 95% CI: 1.01-1.13) were the independent determinants of the primary endpoint. Kaplan-Meier curves also showed a higher incidence of the primary endpoint in the non-A type than type A (Log-rank p = 0.001). Dialysis patients with blood type A developed cardio-cerebrovascular events more frequently than non-A type patients.

Galactose-deficient IgA1 Is Involved in IgA Deposition in Renal Grafts Biopsied One Hour after Kidney Transplantation.

Objective Asymptomatic renal immunoglobulin A (IgA) deposition occurs in healthy subjects, but its etiologic role in disease is unclear. Galactose-deficient IgA1 (Gd-IgA1) is involved in the pathogenesis of IgA nephropathy. We investigated Gd-IgA1 deposition in transplanted kidneys that were considered healthy showing subclinical latent IgA deposition one hour after transplantation. Methods A total of 723 transplanted kidney specimens biopsied 1 h after kidney transplantation from 2009 to 2016 at Nagoya Red Cross Hospital were examined. A total of 81 cases of IgA deposition were extracted, and 41 were ultimately studied. Double immunofluorescence staining for Gd-IgA1 and IgA was conducted to investigate the role of Gd-IgA1 in subclinical IgA deposition. Results Light microscopy findings for the 41 cases indicated only minor glomerular abnormalities. Immunofluorescence analyses revealed that all cases were positive for IgA. C3, IgG, and IgM positivity rates were 78.0%, 7.3%, and 60.9%, respectively. All 41 cases were positive for Gd-IgA1, which merged with IgA deposition in immunofluorescence double staining. IgA disappeared in 26 of 40 cases (65.0%) 1 year after kidney transplantation. In contrast, IgA redeposition was observed in three cases. Conclusion Gd-IgA1 was demonstrated in all transplanted kidneys, with latent IgA deposition noted in otherwise healthy kidneys. Deposition of Gd-IgA1 might indicate the initial stage of IgA nephropathy; however, additional factors, such as IgG deposition, are required for the ultimate development of IgA nephropathy.

Predictors of early remission of proteinuria in adult patients with minimal change disease: a retrospective cohort study.

Previous studies reported conflicting results regarding an association between serum albumin concentration and the cumulative incidence of remission of proteinuria in adult patients with minimal change disease (MCD). The present study aimed to clarify the clinical impact of serum albumin concentration and the cumulative incidence of remission and relapse of proteinuria in 108 adult patients with MCD at 40 hospitals in Japan, who were enrolled in a 5-year prospective cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study (JNSCS). The association between serum albumin concentration before initiation of immunosuppressive treatment (IST) and the cumulative incidence of remission and relapse were assessed using multivariable-adjusted Cox proportional hazards models. Remission defined as urinary protein < 0.3 g/day (or g/gCr) was observed in 104 (96.3%) patients. Of 97 patients with remission within 6 month of IST, 42 (43.3%) developed relapse defined as ≥ 1.0 g/day (or g/gCr) or dipstick urinary protein of ≥ 2+. Serum albumin concentration was significantly associated with remission (multivariable-adjusted hazard ratio [95% confidence interval] per 1.0 g/dL, 0.57 [0.37, 0.87]), along with eGFR (per 30 mL/min/1.73 m2: 1.43 [1.08, 1.90]), whereas they were not associated with relapse. A multivariable-adjusted model showed that patients with high eGFR level (≥ 60 mL/min/1.73 m2) and low albumin concentration (≤ 1.5 g/dL) achieved significantly early remission, whereas those with low eGFR (< 60 mL/min/1.73 m2) and high albumin concentration (> 1.5 g/dL) showed significantly slow remission. In conclusion, lower serum albumin concentration and higher eGFR were associated with earlier remission in MCD, but not with relapse.

Effects of bone turnover status on the efficacy and safety of denosumab among haemodialysis patients.

Denosumab is reported to increase bone mineral density (BMD) among haemodialysis patients; however, hypocalcaemia is a serious adverse effect among chronic kidney disease (CKD) patients. Identifying which patients will show greater improvement in BMD is important. We enrolled 84 haemodialysis patients with osteoporosis in our study. 28 patients initiated denosumab treatment between October 2019 and October 2020. We assessed BMD changes and investigated the association between baseline bone turnover marker (BTM) levels and 6-month changes in BMD after denosumab treatment. BMD was increased at 6 months in denosumab-treated patients compared with patients not treated with denosumab (lumbar spine: 5.34% vs. - 0.49%; total hip: 2.43% vs. - 0.47%). Bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase-5b (TRACP-5b) at baseline were independently associated with increased BMD in the total hip (BAP: ß = 0.472, p value = 0.004; TRACP-5b: ß = 0.433, p value = 0.008) and lumbar spine (BAP: ß = 0.591, p value = 0.001; TRACP-5b: ß = 0.613, p value = 0.0008). BAP and TRACP-5b were also independent predictors of hypocalcaemic events (OR [95% CI] 1.747 [1.084-4.604] and 1.006 [1.000-1.015], respectively). BTMs may be associated with increased BMD and hypocalcaemic events after denosumab treatment. BTM measurement may be useful for assessing the effect of denosumab on BMD; however, careful monitoring of serum calcium levels is needed.

Detecting MUC1 Variants in Patients Clinicopathologically Diagnosed With Having Autosomal Dominant Tubulointerstitial Kidney Disease.

Introduction: Autosomal dominant tubulointerstitial kidney disease (ADTKD)-MUC1 is predominantly caused by frameshift mutations owing to a single-base insertion into the variable number tandem repeat (VNTR) region in MUC1. Because of the complexity of the variant hotspot, identification using short-read sequencers (SRSs) is challenging. Although recent studies have revealed the usefulness of long-read sequencers (LRSs), the prevalence of MUC1 variants in patients with clinically suspected ADTKD remains unknown. We aimed to clarify this prevalence and the genetic characteristics and clinical manifestations of ADTKD-MUC1 in a Japanese population using an SRS and an LRS. Methods: From January 2015 to December 2019, genetic analysis was performed using an SRS in 48 patients with clinically suspected ADTKD. Additional analyses were conducted using an LRS in patients with negative SRS results. Results: Short-read sequencing results revealed MUC1 variants in 1 patient harboring a cytosine insertion in the second repeat unit of the VNTR region; however, deeper VNTR regions could not be read by the SRS. Therefore, we conducted long-read sequencing analysis of 39 cases and detected MUC1 VNTR variants in 8 patients (in total, 9 patients from unrelated families). With the inclusion of family-affected patients (n = 31), the median age at the development of end-stage kidney disease (ESKD) was 45 years (95% CI: 40-40 years). Conclusion: In Japan, the detection rate of MUC1 variants in patients with clinically suspected ADTKD was 18.8%. More than 20% of patients with negative SRS results had MUC1 variants detected by an LRS.

Time to remission of proteinuria and incidence of relapse in patients with steroid-sensitive minimal change disease and focal segmental glomerulosclerosis: the Japan Nephrotic Syndrome Cohort Study.

BACKGROUND: Minimal change disease (MCD) is characterized by a nephrotic syndrome usually steroid-sensitive and a high incidence of relapse of proteinuria. Previous cohort studies have reported conflicting results regarding the association between the time to remission and incidence of relapse. METHODS: This multicenter prospective cohort study included 102 adult patients with steroid-sensitive MCD or focal segmental glomerulosclerosis from a 5-year cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study, who achieved remission of proteinuria within 2 months of immunosuppressive therapy (IST). The association between the time to remission of proteinuria after immunosuppressive therapy and incidence of relapse was assessed using Cox proportional hazards models adjusted for clinically relevant factors. RESULTS: Remission was observed at 3-7, 8-14, 15-21, 22-28, and 30-56 days after initiation of immunosuppressive therapy in 17 (16.7%), 37 (36.3%), 21 (20.6%), 13 (12.7%), and 14 (13.7%) patients, respectively. During a median observation period of 2.3 years after the end of the 2nd month after initiation of immunosuppressive therapy, 46 (45.1%) patients relapsed. The time to remission was associated with the incidence of relapse in an inverse U-shaped pattern (multivariable-adjusted hazard ratios [95% confidence intervals] of the time to remission of 3-7, 8-14, 15-21, 22-28, 30-56 days: 1.00 [reference], 1.76 [0.56, 5.51], 6.06 [1.85, 19.80], 5.46 [1.44, 20.64], and 2.19 [0.52, 9.30], respectively). CONCLUSION: The time to remission was identified as a significant predictor of relapse in steroid-sensitive patients.

Lateral spine dual-energy X-ray absorptiometry and the risk of fragility fractures in long-term kidney graft recipients.

BACKGROUND: Although the prevalence of osteoporosis and fractures in the first 6-12 months post-renal transplantation is high, little is known about the utility of bone mineral density (BMD) to predict fractures in long-term kidney graft recipients. Lateral spine dual-energy X-ray absorptiometry (DXA) scanning is a reliable tool for measuring glucocorticoid-induced and age-related bone loss in the elderly population. However, little is known about the utility of lateral spine DXA for patients with chronic kidney diseases. This study aimed to analyze the utility of lateral spine BMD for fragility fractures in long-term kidney graft recipients. METHODS: A total of 357 stable kidney transplant recipients for a minimum of 1 year after kidney transplantation underwent DXA measurements at several sites, including the lateral spine between January 2017 and December 2018. We collected data on new incident fractures from the patients' medical records. RESULTS: The median post-transplantation time at baseline DXA measurement was 12.6 years. During the median follow-up period of 3.5 years, 41 (11.4%) fractures occurred. The lateral spine BMDs were independently associated with fractures (adjusted hazard ratio 0.076; 95% confidence interval 0.012-0.42, p = 0.003). The cumulative incidence rate of fractures was significantly higher in the lower lateral spine BMD group (< 0.471 g/cm2, optimal cut-off value by receiver operating characteristic curve) than in the higher lateral spine BMD group (23.4 vs. 7.4%, adjusted hazard ratio 4.92; 95% confidence interval 2.33-10.74, p < 0.001). CONCLUSION: Lateral lumbar spine BMD can be used to predict the risk of fragility fractures in long-term kidney graft recipients.

Impact of left ventricular hypertrophy on clinical outcomes in patients with dialysis: a single-center study in Japan.

PURPOSE: Left ventricular hypertrophy (LVH) is a well-known risk factor for poor clinical outcomes in patients undergoing dialysis. However, little evidence supports the above notion in Japan, and the influence of subtypes of LVH on prognosis. METHODS: We investigated 367 patients undergoing dialysis who underwent routine echocardiographic examinations between April and September 2018. LVH was defined as any LV mass ≥ 115 g/m2 in men and ≥ 95 g/m2 in women obtained by echocardiography. The primary endpoint was a composite outcome including all-cause death, admission due to heart failure, and ischemic heart event or stroke. LVH was divided into subtype-groups according to eccentric hypertrophy or concentric hypertrophy, and with and without hypertension. RESULTS: LVH was observed in 171 (47%) patients. The primary endpoint was observed in 58 patients (16%) during the median follow-up period of 500 days. Multivariable Cox regression analyses identified four independent risk factors for the primary endpoint: age, pulse rate, serum albumin level, and LV mass index (per 10-g/m2 increase; hazard ratio: 1.12, 95% confidence interval: 1.06-1.18, P < 0.001). Kaplan-Meier analyses demonstrated that patients with LVH had a worse prognosis than those without LVH in terms of the primary endpoint (log-rank P < 0.001). The incidence of the primary outcome was not significantly different between patients with eccentric or concentric hypertrophy, and between LVH patients with and without hypertension. CONCLUSION: Japanese patients with LVH undergoing dialysis had a worse prognosis than those without LVH in terms of the composite clinical endpoint.

A case of juvenile-onset fibrillary glomerulonephritis diagnosed by mass spectrometry and immunohistochemistry of DNAJB9.

Fibrillary glomerulonephritis (FGN) is a rare glomerular disease. FGN is characterized by the deposition of randomly arranged, nonbranching microfibrils in the mesangium and glomerular basement membrane. The discovery of DNAJ homolog subfamily B member 9 (DNAJB9) in 2017 was a breakthrough, and DNAJB9 has been proven to be extremely useful for the definitive diagnosis of FGN. While FGN often occurs in middle-aged individuals, this case was diagnosed at a relatively young age of 17. We performed renal biopsy, and light microscopic study revealed mesangial proliferation with expansion and subepithelial deposits. Electron microscopic study showed glomerular deposition of randomly oriented nonbranching fibrils with a mean of 20 nm. However, direct first scarlet stain for amyloidosis was weakly positive. Therefore, we confirmed the diagnosis of FGN and eliminated the presence of amyloidosis with mass spectrometry. This is the first case in Japan in which the complication of amyloidosis was ruled out with mass spectrometry and FGN was diagnosed using immunostaining and mass spectrometry of DNAJB9. We began treatment with cyclosporine A. One and a half years after the start of the treatment, kidney function continues to be normal.

Impact of serum magnesium and bone mineral density on systemic fractures in chronic hemodialysis patients.

INTRODUCTION: Bone mineral density (BMD) measured with dual-energy X-ray absorptiometry (DXA) can be used to predict fractures, but its clinical utility has not been fully established in chronic kidney disease (CKD) patients. Magnesium is an essential trace element. Although magnesium is associated with the risk of fractures in non-CKD populations, the relationship is unknown in CKD patients. METHODS: BMD and serum magnesium levels were measured in 358 stable outpatients undergoing maintenance hemodialysis therapy. The primary outcome was fragility fracture. Patients were divided into groups according to the median level of magnesium and the normal threshold value of lumbar spine BMD. RESULTS: During the median follow-up period of 36 months, 36 (10.0%) fractures occurred. The cumulative incidence rates of fractures were 17.6% and 5.2% [adjusted hazard ratio (aHR) 2.31, 95% confidence interval (CI) 1.03-5.17, P = 0.030] in the lower (<2.6 mg/dL) and higher (≥2.6 mg/dL) magnesium (Mg) groups, respectively, and 21.2% and 7.3% (aHR 2.59, 95% CI 1.09-6.16, P = 0.027) in the low- and high-BMD groups, respectively. The lower-Mg and low-BMD group had a 9.21-fold higher risk of fractures (95% CI; 2.35-47.00; P = 0.0010) than the higher-Mg and high-BMD group. Furthermore, adding both magnesium levels and lumbar spine BMD levels to the established risk factors significantly improved the prediction of fractures (C-index: 0.784 to 0.830, p = 0.041). DISCUSSION/CONCLUSIONS: The combination of serum magnesium and lumbar spine BMD can be used for fracture risk stratification and synergistically improves the prediction of fractures in CKD patients.

The importance of kidney volume as a marker in the assessment of living-donor kidney transplantation in Japan.

BACKGROUND: In living kidney transplantation, predicting the risk of end-stage kidney disease in the organ donors though crucial remains to be resolved. Thus, any useful biomarker to predict kidney outcome would be highly desirable to safeguard donors. METHODS: This retrospective study was conducted at Nagoya Daini Red Cross Hospital to confirm whether an increase in preserved kidney volume (PKV) was a predict marker of proteinuria. A change of PKV before and 1 year after kidney donation was measured, and its association with proteinuria 3 years after the donation was analyzed. RESULTS: A total of 119 kidney donors who met the Japanese donor guideline were enrolled. The mean age was 57.4 years, 46.2% were male. The mean values of the variables before kidney donation (baseline) were: BMI levels: 23.4 kg/m2, BSA-adjusted PKV: 132.9 cm3/1.73 m2, and estimated glomerular filtration rate (eGFRave): 82.9 mL/min/1.73 m2. A positive correlation was noted between BSA-adjusted PKV and eGFRave (r = 0.61, p < 0.001). BSA-adjusted PKV increased by 19.5% 1 year after donation, and the median urine protein was 0.04 g/gCre. Linear regression analyses showed that change of PKV and BSA-adjusted PKV before the donation were significantly associated with proteinuria 3 years after donation. CONCLUSION: Change of PKV and BSA-adjusted PKV before donation is important factors for proteinuria after donation under the Japanese donor guidelines. Further studies are needed to confirm whether these factors are associated with renal survival after donation.

Study of Glomerulopathy in Donors after Kidney Transplantation.

INTRODUCTION: Living kidney donation improves the lives of individuals with kidney failure; however, recent studies have suggested that living kidney donors may be at a relatively higher risk of reduced renal function than healthy non-donors. We therefore aimed to evaluate the clinical and pathological findings in living kidney donors who developed kidney disease. METHODS: From January 1991 to May 2019, 1,625 live kidney donations were performed at our hospital. Among the donors, 7 developed kidney disease after donation and underwent open renal biopsy. We studied the clinical and pathological findings of these patients from their clinical records. RESULTS: There were 3 patients with immunoglobulin A (IgA) nephropathy, 2 with membranous nephropathy, 1 with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis, and 1 with secondary focal segmental glomerulosclerosis (FSGS). All patients with IgA nephropathy had latent IgA deposition on their baseline biopsy. One patient with membranous nephropathy demonstrated findings of membranous nephropathy on the baseline biopsy, despite being asymptomatic. All patients, except for those with ANCA-associated nephropathy and secondary FSGS, recovered from the nephritis or maintained an adequate renal function after treatment. DISCUSSION/CONCLUSION: Baseline biopsy is necessary for assessing the renal condition of kidney donors, and these donors require long-term follow-up based on their baseline biopsy findings. If donors develop kidney disease, appropriate diagnosis and treatment are essential.