Renal Outcome of IgM Nephropathy: A Comparative Prospective Cohort Study.

Immunoglobulin M nephropathy (IgMN) is an idiopathic glomerulonephritis characterized by diffuse deposits of IgM in the glomerular mesangium. However, its renal prognosis remains unknown. We compared renal outcomes of IgMN patients with those of patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), or mesangial proliferative glomerulonephritis (MsPGN) from a prospective observational cohort, with 1791 patients undergoing native kidney biopsy in eight hospitals affiliated with The Catholic University of Korea between December 2014 and October 2020. IgMN had more mesangial proliferation and matrix expansion than MsPGN and more tubular atrophy and interstitial fibrosis than MCD. IgMN patients had decreased eGFR than MCD patients in the earlier follow-up. However, there was no significant difference in urine protein or eGFR among all patients at the last follow-up. When IgMN was divided into three subtypes, patients with FSGS-like IgMN tended to have lower eGFR than those with MCD-like or MsPGN-like IgMN but higher proteinuria than MsPGN-like IgMN without showing a significant difference. The presence of hypertension at the time of kidney biopsy predicted ≥20% decline of eGFR over two years in IgMN patients. Our data indicate that IgMN would have a clinical course and renal prognosis similar to MCD, FSGS, and MsPGN.

Spontaneous Renal Artery Dissection Resulting in Renal Infarction: A Case Report and Review of the Literature.

Spontaneous renal artery dissection is a rare disease and an uncommon cause of renal infarction. The patient was a man who presented to the emergency room with sudden-onset right flank pain. Computed tomography revealed right renal infarction; thus, anticoagulation was initiated. Renal angiography revealed luminal narrowing of the segmental artery to the superior pole of right kidney without a dissection flap or false lumen. We stopped anticoagulation due to a lack of evidence of thrombi or luminal narrowing of the dissected vessels. When patients present with acute flank pain, it is important to suspect renal infarction and to perform a correct diagnostic workup, even when the patient shows normal urinalysis results and a normal LDH value.

Overhydration Negatively Affects Quality of Life in Peritoneal Dialysis Patients: Evidence from a Prospective Observational Study.

UNLABELLED: Backgound: This study evaluated whether the hydration status affected health-related quality of life (HRQOL) during 12 months in peritoneal dialysis (PD) patients. METHODS: The hydration status and the HRQOL were examined at baseline and after 12 months using a bioimpedance spectroscopy and Kidney Disease Quality of Life-Short Form, respectively in PD patients. Four hundred eighty-one patients were included and divided according to the baseline overhydration (OH) value; normohydration group (NH group, -2L≤ OH ≤+2L, n=266) and overhydration group (OH group, OH >+2L, n=215). Baseline HRQOL scores were compared between the two groups. The subjects were re-stratified into quartiles according to the OH difference (OH value at baseline - OH value at 12 months; <-1, -1 - -0.1, -0.1 - +1, and ≥+1L). The relations of OH difference with HRQOL scores at 12 months and the association of OH difference with the HRQOL score difference (HRQOL score at baseline - HRQOL score at 12 months) were assessed. RESULTS: The OH group showed significantly lower baseline physical and mental health scores (PCS and MCS), and kidney disease component scores (KDCS) compared with the NH group (all, P<0.01). At 12 months, the adjusted PCS, MCS, and KDCS significantly increased as the OH difference quartiles increased (P<0.001, P=0.002, P<0.001, respectively). In multivariate analysis, the OH difference was independently associated with higher PCS (ß = 2.04, P< .001), MCS (ß=1.02, P=0.002), and KDCS (ß=1.06, P<0.001) at 12 months. The OH difference was independently associated with the PCS difference (ß = -1.81, P<0.001), MCS difference (ß=-0.92, P=0.01), and KDCS difference (ß=-0.90, P=0.001). CONCLUSION: The hydration status was associated with HRQOL and increased hydration status negatively affected HRQOL after 12 months in PD patients.

The Natural Course of Biopsy-Proven Isolated Microscopic Hematuria: a Single Center Experience of 350 Patients.

The increasing interest in healthcare and health screening events is revealing additional cases of asymptomatic isolated microscopic hematuria (IMH). However, a consensus of the evaluation and explanation of the IMH prognosis is controversial among physicians. Here, we present the natural course of IMH together with the pathological diagnosis and features to provide supportive data when approaching patients with IMH. We retrospectively evaluated 350 patients with IMH who underwent a renal biopsy between 2002 and 2011, and the pathological diagnosis and chronic histopathological features (glomerulosclerosis, interstitial fibrosis, and tubular atrophy) were reviewed. Deterioration of renal function was examined during follow up. The patients with IMH were evaluated for a mean of 86 months. IgA nephropathy was the most common diagnosis in 164 patients (46.9%). Chronic histopathological changes were observed in 166 (47.4%) but was not correlated with proteinuria or a decline in renal function. Ten patients developed proteinuria, and all of them had IgA nephropathy. Three patients progressed to chronic kidney disease with an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) but none progressed to end stage renal disease. In conclusion, IMH had a generally benign course during 7-years of observation, although IgA nephropathy should be monitored if it progresses to proteinuria. Future prospective randomized studies may help conclude the long-term prognosis and lead to a consensus for managing IMH.

Benefits of a continuous ambulatory peritoneal dialysis (CAPD) technique with one icodextrin-containing and two biocompatible glucose-containing dialysates for preservation of residual renal function and biocompatibility in incident CAPD patients.

In a prospective randomized controlled study, the efficacy and safety of a continuous ambulatory peritoneal dialysis (CAPD) technique has been evaluated using one icodextrin-containing and two glucose-containing dialysates a day. Eighty incident CAPD patients were randomized to two groups; GLU group continuously using four glucose-containing dialysates (n=39) and ICO group using one icodextrin-containing and two glucose-containing dialysates (n=41). Variables related to residual renal function (RRF), metabolic and fluid control, dialysis adequacy, and dialysate effluent cancer antigen 125 (CA125) and interleukin 6 (IL-6) levels were measured. The GLU group showed a significant decrease in mean renal urea and creatinine clearance (-Δ1.2 ± 2.9 mL/min/1.73 m(2), P=0.027) and urine volume (-Δ363.6 ± 543.0 mL/day, P=0.001) during 12 months, but the ICO group did not (-Δ0.5 ± 2.7 mL/min/1.73 m(2), P=0.266; -Δ108.6 ± 543.3 mL/day, P=0.246). Peritoneal glucose absorption and dialysate calorie load were significantly lower in the ICO group than the GLU group. The dialysate CA125 and IL-6 levels were significantly higher in the ICO group than the GLU group. Dialysis adequacy, ß2-microglobulin clearance and blood pressure did not differ between the two groups. The CAPD technique using one icodextrin-containing and two glucose-containing dialysates tends to better preserve RRF and is more biocompatible, with similar dialysis adequacy compared to that using four glucose-containing dialysates in incident CAPD patients. [Clincal Trial Registry, ISRCTN23727549].

Efficacy of hemocontrol biofeedback system in intradialytic hypotension-prone hemodialysis patients.

We conducted a study to determine whether the hemocontrol biofeedback system (HBS) can improve intradialytic hypotension (IDH) in hypotension-prone hemodialysis (HD) patients compared with conventional HD. In this multicenter prospective crossover study, 60 hypotension-prone patients were serially treated by conventional HD for 8 weeks (period A), by HD with hemoscan blood volume monitoring for 2 weeks (period B0), and by HBS HD for 8 weeks (period B1). The number of sessions complicated by symptomatic IDH during 24 HD sessions (14.9 ± 5.8 sessions, 62.1% in period A vs 9.2 ± 7.2 sessions, 38.4% in period B1, P<0.001) and the number of IDH-related nursing interventions in a session (0.96 ± 0.66 in period A vs 0.56 ± 0.54 in period B1, P<0.001) significantly decreased in period B1 than in period A. Recovery time from fatigue after dialysis was significantly shorter in period B1 than in period A. The patients with higher post-dialysis blood pressure, lower difference between pre- and post-dialysis blood pressure, less frequent IDH, and higher pre- and post-dialysis body weight in period A responded better to HBS in period B1 in regard to the reduction of IDH. In conclusion, HBS may improve the patient tolerability to HD by reducing the IDH frequency and promoting faster recovery from fatigue after dialysis.

Predictors for diabetic retinopathy in normoalbuminuric people with type 2 diabetes mellitus.

BACKGROUND: Previous studies have reported that microalbuminuria is an independent risk factor for the prevalence of diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (DM). For this reason, the clinical significance of DR in normoalbuminuric type 2 DM patients may be overlooked. The aim of this study was to investigate the prevalence of DR and predictors for DR in normoalbuminuric patients with type 2 DM. METHODS: A total 310 patients with type 2 DM and normoalbuminuria, who were referred to the Department of Ophthalmology for screening of DR were included in this study. DR was clinically graded according to the International Clinical Diabetic Retinopathy guidelines. The urinary albumin excretion rate (UAER) was assessed via 24-hour urine collection and measured by immunoturbidimetric assay. Normoalbuminuria was defined as a UAER < 20 µg/min in 2 out of 3 consecutive tests taken within 2-3 months. RESULTS: DR of any grade was present in 64/310 (20.7 %) patients. Mild non-proliferative diabetic retinopathy (NPDR) was most prevalent in patients with DR of any grade (36/64, 56 %). The duration of diabetes (OR 1.01, 95 % CI, 1.01 - 1.02, p < 0.001), hemoglobin levels (OR 0.73, 95 % CI, 0.59 - 0.91, p = 0.004) and a higher tertile of UAER (OR 4.04, 95 % CI, 1.71 - 9.57, p = 0.001) had independently significant association with DR. NPDR as well as PDR was more prevalent in patients with higher tertile of UAER compared with those with lower tertile of UAER (NPDR, p = 0.002 and PDR, p = 0.027, respectively). CONCLUSIONS: Our findings suggest that patients with normoalbuminuric type 2 DM also require close monitoring for the early detection of DR, especially if they have a higher UAER, longer duration of diabetes, or lower hemoglobin levels.

The relationship between the regional abdominal adipose tissue distribution and the serum uric acid levels in people with type 2 diabetes mellitus.

BACKGROUND: Hyperuricemia is associated with obesity. The visceral adiposity and subcutaneous adiposity may be associated with the differential metabolic risk, and the distribution of abdominal adipose tissue was significantly altered in people with type 2 diabetes mellitus (DM) compared to healthy people. Our study was performed to determine to the association between the regional abdominal adipose tissue distribution and serum uric acid levels in people with type 2 DM. METHODS: A total of 699 people with type 2 DM and who had undergone abdominal computed tomography assessment of the visceral fat area and subcutaneous fat area were included. The serum uric acid levels were measured by the uricase method. Hyperuricemia was defined by cut-off value of > 7 mg/dl for men and > 6 mg/dl for women. RESULTS: The visceral fat area was positively associated with the serum uric acid levels after adjustment for age, sex, systolic blood pressure, diastolic blood pressure, serum creatinine, hemoglobin, serum albumin, serum high-density lipoprotein, serum triglyceride and hemoglobin A1c (ß-coefficient = 0.117, p < 0.001). The logistic regression analysis showed that the visceral fat area was the significant independent predictor of hyperuricemia (OR 2.33, 95% CI, 1.21-4.50, p = 0.012). But there was no significant association between the subcutaneous fat area and the serum uric acid levels (ß-coefficient = 0.061, p = 0.255). CONCLUSIONS: our data shows that the visceral fat area was positively associated with the serum uric acid levels, but the subcutaneous fat area was not in people with type 2 DM.

The role of autophagy in unilateral ureteral obstruction rat model.

AIM: Autophagy is a cellular process of degradation of damaged cytoplasmic components and regulates cell death or proliferation. Unilateral ureteral obstruction (UUO) is a model of progressive renal fibrosis in the obstructed kidney. And UUO is followed by compensatory cellular proliferation in the contralateral kidney. We investigate the role of autophagy in the obstructed kidney and contralateral kidney after UUO. METHODS: To obtain the evidence and the patterns of autophagy during UUO, the rats were sacrificed 3, 7 and 14 days after UUO. To examine the efficacy of the autophagy inhibitors, 3-methyladenine (3-MA), the rats were treated daily with intraperitoneal injection of 3-MA (30 mg/kg per day) for 7 days. RESULTS: After UUO, autophagy was induced in the obstructed kidney in a time-dependent manner. Inhibition of autophagy by 3-MA enhanced tubular cell apoptosis and tubulointerstitial fibrosis in the obstructed kidney after UUO. In the contralateral kidney, autophagy was also induced and prolonged during UUO. Inhibition of autophagy by 3-MA increased the protein expression of proliferating cell nuclear antigen significantly in the contralateral kidney after UUO. The Akt-mammalian target of rapamycin (mTOR) signalling pathway was involved in the induction of autophagy after UUO in both kidneys. CONCLUSION: Our present results support that autophagy induced by UUO has a renoprotective role in the obstructed kidney and regulatory role of compensatory cellular proliferation in the contralateral kidney through Akt-mTOR signalling pathway.

Relationship between erythropoietin resistance index and left ventricular mass and function and cardiovascular events in patients on chronic hemodialysis.

The response to erythropoietin (EPO) treatment varies considerably in individual patients on chronic hemodialysis. The EPO resistance index (ERI) has been considered useful to assess the EPO resistance and can be easily calculated in the clinic. The aim of this study was to investigate the association between ERI and left ventricular mass (LVM) and function and to determine whether ERI was associated with cardiovascular events in patients on hemodialysis. This study was designed prospectively. Clinical, laboratory, and echocardiographic variables were assessed in 72 patients on hemodialysis. The ERI was determined as the weekly weight-adjusted dose of EPO (U/kg/week) divided by hemoglobin concentration (g/dL). Patients were divided into three groups by tertiles of ERI. Patients with higher tertiles of ERI had a higher LVM index and lower LV ejection fraction compared with those with lower tertiles of ERI (P = 0.019 and P = 0.030, respectively). The median follow-up period was 53 months. The Kaplan-Meier plot showed increased frequency of cardiovascular events in patients with higher tertiles of ERI, compared with those with lower tertiles of ERI (P = 0.011, log-rank test). The multivariate Cox proportional hazard models showed that the ERI was the significant independent predictor of cardiovascular events (HR 3.00, 95% CI, 1.04-8.62, P = 0.042). Our data show that ERI was related with LVM index, LV systolic function and cardiovascular events in patients with hemodialysis. By monitoring of ERI, early identification of the EPO resistance may be helpful to predict the cardiovascular risk in hemodialysis patients.

Relationship of visceral and subcutaneous adiposity with renal function in people with type 2 diabetes mellitus.

BACKGROUND: Obesity and diabetes mellitus (DM) are established risk factors for the development of chronic kidney disease. Visceral adiposity (VAT) and subcutaneous adiposity (SAT) may be associated with the differential metabolic risk. Our study was performed to determine whether VAT or SAT was associated with the decrease of renal function in people with type 2 DM. METHODS: Nine hundred and twenty-nine people with type 2 DM and who had undergone abdominal computed tomography assessment of the SAT and VAT areas were included. The estimated glomerular filtration rate (eGFR) was calculated using the Cockcroft-Gault equation and the Modification of Diet in Renal Disease (MDRD) four-variable equation at the time of the assessment of the SAT and VAT areas. RESULTS: VAT was negatively associated with eGFR using the MDRD equation after adjustment for the clinical variables (ß-coefficient = - 0.075, P = 0.034), while SAT was not significantly associated with eGFR. There was no significant association between the abdominal adiposity measurements and the eGFR using the Cockcroft-Gault formula. When stratifying the individuals by the body mass index groups, VAT was negatively associated with eGFR by the MDRD equation and the Cockcroft-Gault formula in the overweight and obese subjects after adjustment for the clinical variables, while there was no significant association between the VAT and the eGFR in the normal weight subjects. SAT was not significantly associated with eGFR in the normal weight, overweight and obese subjects. CONCLUSIONS: Our data suggest that VAT may be an additional prognostic factor for the decrease of renal function especially in the overweight or obese subjects with type 2 DM.

Association between N-terminal pro-brain natriuretic peptide and acute ischemic stroke in patients on chronic hemodialysis.

BACKGROUND: Plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) has been reported as a predictor for ischemic stroke in general population. However, predictive value of plasma NT-proBNP for acute ischemic stroke in patients on chronic hemodialysis has not been well established. The aim of this study was to determine whether NT-proBNP could predict acute ischemic stroke in patients on chronic hemodialysis. METHODS: This study was designed prospectively. Clinical, laboratory, and echocardiographic variables were assessed in 72 patients on chronic hemodialysis. The plasma levels of NT-proBNP were measured by immunoassay. RESULTS: During the follow-up period of 45 months, 11 patients had an acute ischemic stroke. The Kaplan-Meier plot showed an increased frequency of acute ischemic stroke in patients with plasma levels of NT-proBNP above the median values compared to patients with lower concentrations (P = 0.028). The multivariate Cox proportional hazard models showed that the NT-proBNP was a significant independent predictor of acute ischemic stroke after adjustment for age, sex, mean blood pressure, diabetes, serum cholesterol levels, left ventricular mass index, and left ventricular fractional shortening (HR 6.66, 95% CI, 1.22-36.48, P = 0.029). CONCLUSIONS: Our data suggest that plasma NT-proBNP levels predict the risk of acute ischemic stroke in patients on chronic hemodialysis.

Natural history and renal pathology in patients with isolated microscopic hematuria.

BACKGROUND/AIMS: No definite conclusions have been reached about the natural history of patients with isolated microscopic hematuria (IMH). In this study, we observed the natural history of patients with IMH and examined factors related to a pathologic diagnosis and subsequent prognosis. METHODS: We retrospectively evaluated 156 subjects with IMH who had a renal biopsy performed. Of the 156 subjects, 33.3% were diagnosed with IgA nephropathy, 23.7% with mesangial proliferative glomerulonephritis, 15.4% with glomerular minor lesion, and 12.8% with thin basement membrane nephropathy; 6.4% had normal biopsies. RESULTS: We followed up with 100 subjects for about 31 months. During this follow-up period, two subjects who had received a pathologic diagnosis of IgA nephropathy developed chronic kidney disease. During the course of the study, one of these subjects presented with proteinuria and hypertension and the other with proteinuria. The overall incidences of proteinuria and hypertension were 6% and 5% respectively. CONCLUSIONS: The prognosis for patients with IMH was relatively favorable, but patients developing proteinuria and/or hypertension require careful observation and management during the follow-up period.

A synonymous genetic alteration of LMX1B in a family with nail-patella syndrome.

The gene responsible for nail-patella syndrome, LMX1B, has recently been identified on chromosome 9q. Here we present a patient with nail-patella syndrome and an autosomal dominant pattern of inheritance. A 17-year-old girl visited our clinic for the evaluation and treatment of proteinuria. She had dystrophic nails, palpable iliac horns, and hypoplastic patellae. Electron microscopy of a renal biopsy showed irregular thickening of the glomerular basement membrane. A family history over three generations revealed five affected family members. Genetic analysis found a change of TCG to TCC, resulting in a synonymous alteration at codon 219 in exon 4 of the LMX1B gene in two affected family members. The same alteration was not detected in an unaffected family member. This is the first report of familial nail-patella syndrome associated with an LMX1B in Korea mutation, However, we can not completely rule out the possibility that the G-to-C change may be a single nucleotide polymorphism as this genetic mutation cause no alteration in amino acid sequence of LMX1B.

Status of initiating pattern of hemodialysis: a multi-center study.

This study was to evaluate the status of initiating pattern of hemodialysis (HD). Five hundred-three patients in 8 University Hospitals were included. Presentation mode (planned vs. unplanned), and access type (central venous catheters [CVC] vs. permanent access) at initiation of HD were evaluated, and the influence of predialysis care on determining the mode of HD and access type was also assessed. Most patients started unplanned HD (81.9%) and the most common initial access type was CVC (86.3%). The main reason for unplanned HD and high rate of CVC use was patient-related factors such as refusal of permanent access creation and failure to attend scheduled clinic appointments. Predialysis care was performed in 57.9% of patients and only 24.1% of these patients started planned HD and 18.9% used permanent accesses initially. Only a minority of patients initiated planned HD with permanent accesses in spite of predialysis care. To overcome this, efforts to improve the quality of predialysis care are needed.

The impact of the aortic pulse wave velocity on the cardiovascular outcomes of hemodialysis patients.

The aims of our study were to identify the risk factors for an increased aortic pulse wave velocity (AoPWV) and to assess the impact of the AoPWV on the cerebro-cardiovascular (CV) outcomes of hemodialysis (HD) patients. Seventy two HD patients were included, and the AoPWV, the echocardiography and the biochemical parameters were measured. After dividing the patients into tertiles according to the AoPWV values, we defined the low, the middle and the high AoPWV groups. The patients in the high AoPWV group showed a significantly higher age and high-sensitivity C-reactive protein level, a greater prevalence of diabetes and statin use, left ventricular hypertrophy, average pulse pressure (PP), AoPWV and left ventricular mass index and a lower serum albumin level than those in the low AoPWV group (p<0.05). On multivariate regression analysis of the AoPWV, age and the average PP were independently related to the AoPWV (p<0.05). On the multivariate Cox analysis for CV outcomes, the AoPWV and the average PP remained significant independent predictors of CV events. Our data suggest that an increased AoPWV is an independent predictor for the CV outcomes of HD patients.

Acquired gitelman syndrome.

Acquired renal tubular disorder can be observed in various disease processes, especially autoimmune diseases. Gitelman syndrome is an autosomal recessive disease characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria. This disorder is caused by mutation in the SLC12A3 gene, which encodes the thiazide-sensitive NaCl cotransporter (NCCT). Acquired Gitelman syndrome has been reported and the majority has been associated with Sjögren's syndrome. The presence of circulating auto-antibodies to NCCT was suggested as a mechanism of acquired Gitelman syndrome. Treatment of acquired Gitelman syndrome was done with supplements of potassium and magnesium and prednisone was effective in some cases. Acquired Gitelman syndrome should be included in the differential diagnosis of renal involvement in patients with autoimmune diseases, especially Sjögren's syndrome.

Acquired Gitelman syndrome in a patient with primary Sjögren syndrome.

Acquired Gitelman syndrome (GS) associated with Sjögren syndrome (SS) is rare, and the test to determine the pathophysiological state of acquired GS in patients with primary SS has not been reported previously. A 47-year-old woman with sicca complex presented to our clinic with intermittent muscle cramping and weakness involving both lower extremities over several months. Laboratory findings showed hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria, which met the criteria for GS. Diagnostic evaluation identified primary SS as the cause of the acquired GS. Light microscopic examination of renal tissue from the patient showed mild tubulointerstitial nephritis. Immunohistochemical staining of renal tissue showed the absence of the sodium-chloride cotransporter (NCCT) in the distal convoluted tubules. Incubation of the patient's serum with normal mouse kidney tissue showed a pattern of NCCT in the distal convoluted tubules similar to that of incubation of normal mouse kidney with the rabbit polyclonal anti-NCCT antibody. This is a rare case of acquired GS associated with primary SS, and our findings suggest the presence of circulating autoantibodies to NCCT.