Seung Duk Hwang

Validation of the Oxford classification of IgA nephropathy: a single-center study in Korean adults.

Background/Aims The recently published Oxford classification of IgA nephropathy (IgAN) proposed a split system for histological grading, based on prognostic pathological features. This new classification system must be validated in a variety of cohorts. We investigated whether these pathological features were applicable to an adult Korean population. Methods In total, 69 adult Korean patients with IgAN were analyzed using the Oxford classification system at Soonchunhyang University Hospital, Seoul, Korea. All cases were categorized according to Lees classification. Renal biopsies from all patients were scored by a pathologist who was blinded to the clinical data for pathological variables. Inclusion criteria were age greater than 18 years and at least 36 months of follow-up. We excluded cases with secondary IgAN, diabetic nephropathy combined other glomerulopathies, less than 36 months of follow-up, and those that progressed rapidly. Results The median age of the patients was 34 years (range, 27 to 45). Mean arterial blood pressure was 97 ± 10 mmHg at the time of biopsy. The median follow-up period was 85 months (range, 60 to 114). Kaplan-Meier analysis showed significant prognostic predictions for M, E, and T lesions. A Cox proportional hazard regression analysis also revealed prognostic predictions for E and T lesions. Conclusions Using the Oxford classification in IgAN, E, and T lesions predicted renal outcome in Korean adults after taking clinical variables into account.

Mesenchymal stem cell therapy for chronic renal failure

Importance of the field: Chronic kidney disease (CKD) has become a worldwide public health problem. Renal transplantation is the treatment of choice for end-stage renal disease, but is limited by a small number of organ donors and the immune barrier. To overcome these problems, new therapeutic strategies for tissue repair have recently emerged. Areas covered in this review: We discuss the therapeutic potential of mesenchymal stem cells (MSCs) in kidney injury and examine the latest reports providing evidence supporting MSC efficacy in the treatment of chronic renal failure (CRF). What the reader will gain: MSCs improve histological and functional outcomes in various CRF model systems. Paracrine effects rather than transdifferentiation might result in the prevention of progressive renal failure. In addition, MSCs can reprogram kidney cell differentiation, and modulate neo-kidney transplantation in CRF. Take home message: Although many practical problems remain to be addressed, treatment with MSCs will enter the mainstream of CRF treatment.

Changes in body fat mass in patients after starting peritoneal dialysis.

♦ Background: Peritoneal dialysis (PD) is characterized by gain in fat mass. Visceral fat mass is associated with metabolic syndrome and atherosclerosis rather than subcutaneous fat mass. In addition, the change in visceral fat mass is a more reliable predictor of survival in PD patients. In this study, we prospectively examined serial changes in fat composition and nutritional status and analyzed factors associated with gain in fat mass in patients undergoing PD. ♦ Methods: Body composition was assessed by bioelectric impedance analysis (BIA) and computed tomogram (CT). Nutrition status was assessed by Subjective Global Assessment (SGA), protein equivalent of nitrogen appearance (nPNA), serum albumin, C-reactive protein (CRP), and lipid profile. All measurements except BIA were performed on the seventh day and at 6 and 12 months after the start of PD. ♦ Results: 60 patients (30 men; mean age 55.0 ± 12.5 years) were enrolled. Increase in body weight continued during the 12 months but visceral and subcutaneous fat mass increased during the first 6 months and decreased during the second 6 months. While hematocrit and serum albumin decreased during the first 6 months, they did not change during the second 6 months. Serum creatinine, total cholesterol, and triglyceride increased similarly to the weight pattern. While nPNA decreased during the 12 months, Kt/V, SGA, and CRP did not change. Patients that had more visceral fat mass at the start of PD had less gain of visceral fat mass during the first 6 months (r = –0.821, p = 0.002). Patients that had more subcutaneous fat mass at the start of PD had less gain of subcutaneous fat mass (r = –0.709, p = 0.015). The change in weight was not associated with the change in visceral or subcutaneous fat during the first 6 months. ♦ Conclusion: Patients starting PD experience weight gain, including visceral and subcutaneous fat, during the first 6 months of PD. Patients with high baseline fat mass had less increase in fat mass than those with low baseline fat mass, regardless of visceral or subcutaneous fat mass.

Effect of Prolonged Subcutaneous Implantation of Peritoneal Catheter on Peritonitis Rate during CAPD: A Prospective Randomized Study

We conducted a prospective randomized controlled study to confirm our earlier observation that prolonged subcutaneous implantation of peritoneal catheter reduced peritonitis rate when compared to retrospective data from patients with catheters placed by conventional access technique. A total of 60 patients were randomized into two groups: 30 patients had catheters left implanted subcutaneously for 6 weeks (I) and the other 30 patients had catheters inserted by conventional technique and had 6 weeks of break-in period (C). Subgroups of 15 patients each with new and conventional techniques used Y-connector (IY, CY) and remaining patients used standard spikes (IS, CS).Mean age was 47.7 years (range 16–71); 61.0% were male and 44.1% diabetics. Peritonitis, exit site infection, simultaneous peritonitis and exit site infection, and complication related to Staphylococcus or Pseudomonas infections were observed for up to 2 years in each patient after initiation of bag exchange or until termination of CAPD by transfer to hemodialysis or by death.Total duration of observation was 493.2 patient-months for new access technique and 409.6 patient-months for conventional technique. Patients in IY group had the lowest incidence of peritonitis (1/14.9 patient-months) and exit site infection (1/16.8 patient-months) among four subgroups. Peritonitis rate in IY was significantly lower compared to CY or CS. The total peritonitis-free period in those patients who did not experience peritonitis during the observation period was also significantly longer in IY (120 patient-months) than in CY (26 patient-months), IS (10.6 patient-months), or CS (10.4 patient-months). Simultaneous peritonitis and exit site infection was observed in none of IY group but 3 episodes in CY, 4 episodes in IS, and 3 episodes in CS. The rates of complications related to Staphylococcus aureus and Pseudomonas infections were also significantly lower in IY than in CY, IS, or CS. Technique survival did not differ between the two groups.The present results confirm our previous observation that the new access technique reduces the incidence of peritonitis probably by reducing infection via periluminal route. The Y-connector system further reduces peritonitis rate by reducing infection via intraluminal route.

Could mean platelet volume be a promising biomarker of progression of chronic kidney disease

Abstract The mean platelet volume (MPV), a readily available indicator of platelet activation and function, is a useful predictive and prognostic biomarker of cardiovascular and cerebrovascular disease (CVD). It is associated with a variety of prothrombotic and proinflammatory diseases. Larger platelets are more likely to aggregate and release greater quantities of adhesive molecules. MPV has seldom been investigated in patients with chronic kidney disease (CKD). This study aimed to investigate the relationship between MPV levels and the glomerular filtration rate (GFR) in patients with CKD. We reviewed the medical records of patients with CKD who visited the nephrology outpatient clinics of Soonchunhyang University Bucheon Hospital between January 2010 and May 2013. A total of 553 patients were included in the present retrospective study. According to the estimated GFR (eGFR) calculated by the abbreviated the Modification of Diet in Renal Disease (MDRD) equation, the patients were allocated to Group 1 (GFR, 60–89 ml/minute/1.73 m2; n = 64), Group 2 (GFR, 30–59 ml/minute/1.73 m2; n = 268), Group 3 (GFR, 15–29 ml/minute/1.73 m2; n = 147), or Group 4 (GFR, <15 ml/minute/1.73 m2 and non-dialysis; n = 74). Data were analyzed by Student’s t-test, the chi-squared test, Pearson’s correlation coefficient (r), Tukey’s honestly significant difference (HSD) test, and one-way analysis of covariance. The MPV values had a negative correlation with eGFR in patients with CKD (Pearson’s correlation coefficient = −0.553, p < 0.001). The mean MPV values in Groups 1–4 were 9.81 ± 0.13 fl, 10.34 ± 0.08 fl, 10.86 ± 0.09 fl, and 11.19 ± 0.11 fl, respectively (p < 0.001). Multiple comparisons of MPV values in the four groups by Tukey’s HSD test showed statistically significant intergroup differences, with all p values <0.001. Platelet counts and PDW decreased along with eGFR, and there were no significant differences with respect to plateletcrit. Patients with prevalent coronary artery disease (CAD) or CVD had higher MPVs than did those without CAD or CVD. MPV was significantly increased with progression of CKD. MPV may be a useful indicator of increased risks of CAD or CVD in patients with CKD.

A case of CMV disease of the jejunum in a patient with non-Hodgkin's lymphoma.

CMV infection may occur anywhere in the gastrointestinal tract. Among the small intestine, ileum is the most common site of CMV disease and infection of jejunum is a rare one in patients with CMV gastroenteritis. Although rare, the reason why the recognition of this diagnosis is important is that it cause the lethal hemorrhage and perforation of gastrointestinal tract when its diagnosis and treatment was delayed. Rapid diagnosis are able to using the immunohistochemical stain in shell vial culture of infected specimen or peripheral neutrophils preparation in viremic patients within 8 to 36 hours. The treatment of choice is antiviral agent or surgical resection. We experienced a case of CMV disease of jejunum in patient with non-Hodgkin’s lymphoma who showed severe ulceration in jejunum and massive intestinal hemorrhage, and he survived after successful treatment with segmental resection of jejunum and intravenous ganciclovir.

Ischemic monomelic neuropathy: a rare complication after vascular access formation

To the Editor, Patients with end-stage renal disease require an arteriovenous fistula (AVF). Although an AVF has numerous advantages, it can result in neurological or ischemic problems with hemodynamic disturbance. In 1983, Wilbourn et al. [1] described ischemic monomelic neuropathy (IMN), defined as a type of multiple axonal-loss mononeuropathy distally in a limb, resulting from an impaired blood supply after graft insertion. IMN is a very rare complication, but requires an early diagnosis and treatment. We report a case of IMN after an AVF operation and the results of a literature review. A 44-year-old woman visited a vascular surgeon for hemodialysis access. She had been diagnosed with type 2 diabetes 15 years previously. She had a 3-year history of hypertension and chronic kidney disease and was a hepatitis B virus carrier. Laboratory studies showed a white blood cell count of 5,600/mL, hemoglobin of 9.1 g/dL, blood urea nitrogen (BUN) of 49.3 mg/dL, and serum creatinine of 7.6 mg/dL. The patient had outpatient surgery with a brachiocephalic graft on the left elbow. The patient was admitted 7 days af ter the operation for weight gain, dyspnea, and general weakness. At that time, the hemoglobin was 8.2 g/dL, BUN 93.3 mg/dL, and serum creatinine 17.6 mg/dL. Metabolic acidosis was noted and a chest X-ray showed mild pulmonary congestion. The patient underwent emergency hemodialysis via a jugular vein catheter. After her uremia improved, she complained of swelling and numbness of the left hand and reduced grip strength. On examination, the fistula was patent and her radial pulse was palpable. The movement of the thumb was weak and she could not move her other fingers. She had no sensation in any modality. Nerve conduction studies performed 3 weeks postoperatively showed a decreased nerve conduction velocity and amplitude for the motor and sensory parts of the left hand (Table 1). Both lower legs had markedly decreased motor and sensory function, compatible with a diabetic patient. We diagnosed IMN of the left hand and peripheral polyneuropathy of both legs. Table 1 Nerve conduction study of upper extremities: initially Although she required fistula ligation, we and the surgeon decided to observe her because 1 month had already passed since the first operation and an extra ligation would require another operation for access. Her diabetic polyneuropathy was treated with pregabalin. After 2 months, she could grip a pencil. A follow-up nerve conduction test revealed improvement in the ulnar nerve, although defects remained in the median nerve (Table 2). She did not want to undergo more surgery. So we continued to observe her as an outpatient. Table 2 Nerve conduction study of upper extremities: after 2 months IMN is a sensory/motor impairment without tissue necrosis, but with a transient reduction in blood flow. IMN is a form of steal phenomenon as the access surgery steals blood flow from distal nerve tissue [2], causing multiple axonal-loss mononeuropathy distally in the limb. IMN is often under-recognized and misdiagnosed, but its known incidence is 0.5% to 3.0% [3]. If a patient on hemodialysis complains of hand pain, physicians need to consider many diseases, including soft tissue swelling, wound hematoma, carpal tunnel syndrome, vascular steal syndrome, and IMN [4]. The most important factor in diagnosing IMN is that of the clinical manifestations. Acute pain, weakness, and muscle paralysis immediately after an operation are common symptoms. Since these symptoms are nonspecific, after AVF formation, the motor or sensory function of the operated hand should be checked and nerve conduction studies should be done. Low amplitudes and reduced or even undetectable motor or sensory nerve conduction velocities are compatible with IMN. Axonal loss of the median, radial, and ulnar nerves can also be observed [3]. Electromyograms show denervation, including fibrillation potentials and motor unit loss. Since past neuropathy can be assumed to lower the ischemic injury threshold, diabetes, atherosclerotic disease, and women have an increased risk of IMN [2,4,5]. Nevertheless, IMN has been reported for a patient with no risk factors. In addition, a brachiocephalic fistula is commonly associated with this complication because the brachial artery is the only blood supply to the distal arm. The most important treatment for IMN is immediate closure of the access; this increases the probability of recovery [3,4]. Early closure of the fistula leads to partial or full restoration of the sensory and motor function [5]. Some clinicians reported treatment using a banding operation [3]. Redfern and Zimmerman [5] reported an improvement in two patients under observation, like our case. However, it is not clear whether those patients had IMN [5]. Anticonvulsants, antidepressants, and narcotics have been used for pain control [2]. Better education and awareness on the part of the surgeon and nephrologist should lead to an early diagnosis and the proper management of IMN [4]. Therefore, we report this case of IMN after an AVF operation with a literature review.

Does Body Fat Mass Define Survival in Patients Starting Peritoneal Dialysis

♦ Background and Aims: Peritoneal dialysis (PD) is characterized by a gain in fat mass. Unlike subcutaneous fat, visceral fat is associated with metabolic syndrome and survival. We prospectively examined whether visceral or subcutaneous fat could predict outcome in patients undergoing PD. ♦ Methods: We studied 117 new patients (57 men) undergoing PD between February 2006 and November 2011. Baseline body composition was measured on computed tomograms. Visceral obesity was defined as a visceral fat area exceeding 100 cm2, and subcutaneous obesity, as a subcutaneous fat area exceeding 130 cm2. ♦ Results: Among the 117 patients, 37 and 29 were diagnosed with visceral and subcutaneous obesity respectively. Visceral and subcutaneous obesity were both present in 21 patients. In the study population, the 1-year and 5-year survival rates were 94% and 59%. The rates of peritonitis and exit-infection were 0.31 and 0.14 episodes per patient-year. Mortality was greater in patients with visceral obesity than in those without visceral obesity (p = 0.005). Visceral obesity had no influence on peritonitis and exit-infection rates. Subcutaneous obesity was associated neither with survival nor with peritonitis or exit-site infection. In a multivariate Cox regression analysis, visceral obesity was not a risk factor for poor outcome. ♦ Conclusions: Increased visceral fat at PD initiation is not an independent predictor of poor survival. Any impact of visceral or subcutaneous fat mass on outcomes in patients undergoing PD would be better defined by larger, long-term studies.

Reanalysis of membranoproliferative glomerulonephritis patients according to the new classification: a multicenter study

Background All types of membranoproliferative glomerulonephritis (MPGN) are progressive diseases with poor prognoses. Recently, a newly proposed classification of these diseases separated them into immune complex- and complement-mediated diseases. We investigated the frequency of C3 glomerulonephritis among previously diagnosed MPGN patients. Methods We conducted a retrospective study of patients diagnosed with MPGN at three tertiary care institutions between 2001 and 2010. We investigated the incidence of complement-mediated disease among patients diagnosed with MPGN. Progressive renal dysfunction was defined as a 50% reduction in the glomerular filtration rate or the need for renal replacement therapy. Results Among the 3,294 renal biopsy patients, 77 (2.3%) were diagnosed with MPGN; 31 cases were excluded, of which seven were diagnosed with systemic lupus nephritis, and the others were not followed for a minimum of 12 months after biopsy. Based on the new classification, complement-mediated MPGN was diagnosed in two patients (4.3%); only one patient developed progressive renal dysfunction. Among the immune complex-mediated MPGN patients, 17 patients developed progressive renal dysfunction. Serum albumin and creatinine levels at the time of MPGN diagnosis were risk factors of renal deterioration, after adjusting for low C3 levels and nephrotic syndrome. Conclusion Complement-mediated glomerulonephritis was present in 4.3% of patients previously diagnosed with MPGN.

Use of multidetector computed tomography for evaluating coronary artery disease in patients undergoing dialysis

Aim:  Cardiovascular disease is the most common cause of death in patients undergoing dialysis. The accuracy of multidetector computed tomography (MDCT) for detecting coronary disease has not been determined, and little information is available regarding the performance of MDCT in patients undergoing dialysis.