Citrate attenuates tubulointerstitial fibrosis in 5/6 nephrectomized rats by decreasing transforming growth factor-beta1.

OBJECTIVE: Tubulointerstitial fibrosis plays an essential role in progression to end stage renal disease (ESRD) in various chronic renal failure (CRF) models including the 5/6 nephrectomy (5/6). The present study examines the renoprotective effect of citrate in the renal ablative model that is quite similar to CRF in human. MATERIAL AND METHOD: Male Wistar rats underwent 5/6 and were fed with tap water (5/6tap) or tap water containing 67 mEq/L citrate solution (5/6cit). Sham-operated rats (S) were divided into Stap and Scit groups. Renal function, renal histopathology, renal alpha-Smooth muscle actin (SMA), and renal transforming growth factor (TGF)-beta1 were determined immediately and at the 8th week after operation. RESULTS: Following the surgery, the values of glomerular filtration rate (GFR) in the 5/6tap and the 5/6cit groups were 2.39 +/- 0.25 and 2.35 +/- 0.25 (mL/kg/min), respectively, both were significantly lower than sham groups (p < 0.05). At the eighth week, the 5/6tap group had progressively decreased GFR and had higher fibrosis score, increased alpha-SMA positive cells, and renal tissue TGF- beta1 when compared with the sham groups. The 5/ 6cit group, when compared with the 5/6tap group, had higher GFR (2.51 +/- 0.22 vs 1.17 +/- 0.33 mL/kg/min; p < 0.05), lower fibrosis score (1.83 +/- 0.88 vs 3.0 +/- 0.4, p < 0.001), lower alpha-SMA activity (159 +/- 2.9 vs 187 +/- 12.3 cells per 1000 interstitial cells, p < 0.05), and lower renal TGF-beta1 levels (1771.3 +/- 239.5 vs 4716.9 +/- 871.2 pg/mg protein, p < 0.005). CONCLUSION: As such, in 5/6 nephrectomized rats, citrate therapy for eight weeks could decrease tubulointerstitial fibrosis mainly by reducing the heightened renal TGF-beta1 levels and additionally by attenuating the increased myofibroblast activity.

A rare case of chylous ascites and chyluria in an adult nephrotic syndrome with focal segmental glomerulosclerosis.

The authors report the first case of chylous ascites and chyluria in a 65-year-old Thai women with nephrotic syndrome due to focal segmental glomerulosclerosis (FSGS), tip variant. She presented with generalized edema and abdominal discomfort. Abdominal paracentesis revealed milky white fluid. Chylous ascites was confirmed. Abdominal and thoracic computed tomography did not show any cause of chylous ascites and chyluruia. Lymphoscintigraphy could not demonstrate lymph flow obstruction and connection between lymphatic pathway and KUB system. Those could have explained the chylous ascites or chyluria. Hypoalbuminemia-induced bowel edema may predispose to change the permeability of mucosal or serosal lymphatics. This could result in chylous ascites but the cause of chyluria could not be determined in this case.

Alleviation of renal and pulmonary injury by immunomodulation in leptospirosis: hamster model.

OBJECTIVE: Severe leptospirosis manifestations include acute renal failure, caused by acute interstitial nephritis and pulmonary hemorrohage. Spirochete invasion and toxicity of outer membrane cause robust inflammatory host responses. These responses lead to the generation of cytokines, chemokines, and inflammatory cell infiltrations which result in severe organ dysfunctions. The immunomodulation by the modulation of host immune response may alleviate the renal and pulmonary injury. The authors determined whether the current immunosuppressive agents could alleviate the inflammation and minimize the organ injury in hamster model. MATERIAL AND METHOD: The animal experiments were conducted with the approval of The Ethical Research Committee of Chulalongkorn University Hospital. The leptospira interrogan serovar pyrogenese was isolated from a wild rat. The spirochete was grown in Fletcher's semisolid media and after subcultures were transferred to the Fletcher's liquid media. An amount of 0.5 ml of the spirochete culture media containing 1 x 10(8) leptospires/ml was intraperitoneally injected to golden Syrian hamsters (Mesocrietus auratus), age 4-6 weeks, weighing 60-80 grams. The hamsters were randomed into 5 groups (n = 4 in each group) namely, 1) Normal group (Control group), 2) Leptospira group, 3) CsA group (leptospira with cyclosporine feeding, 100 mg/kg/ day), 4) Rapa group (leptospira with rapamicin feeding, 0.6 mg/kg/day), and 5) Irra group (leptospira with irradiation). Cyclosporine and rapamicin were started at day 0 after the spirochete injection. Gamma ray dose 200 cGy was irradiated to the hamster 3 days before the spirochete inoculation. The animals were autopsied or euthanized if expired or at day 5 post inoculation. The blood samples for BUN, and creatinine were drawn before the inoculation and at autopsy or euthanasia. RESULTS: The inoculation of L Interrogan 0.5 ml (1 x 10(8) leptospires/ml) without immunomodulation cause mortality of all animals at day 4 or day 5 post inoculation. The blood chemistry showed acute severe azotemia. The autopsy findings revealed severe interstitial nephritis and severe pulmonary hemorrhage. The hamsters in the Rapa group had only minimal pulmonary hemorrhage and minimal focal interstitial inflammation of kidney. There were cytoadherance of inflammatory cells to the endothelial cells in lungs and kidneys without the intrusion into the interstitium. The blood chemistry in Rapa group showed mild elevation of BUN and Cr. The immunomodulation by cyclosporine and irradiation did not alleviate the disease. On the contrary, cyclosporine and irradiation caused more severe histopathology. CONCLUSION: The immunomodulation by rapamicin in leptospirosis in hamsters could alleviate the kidney and pulmonary injuries. The up-regulation of IL-2 in peripheral blood lymphocytes did not result in the kidney and pulmonary injuries.

Study of cyclosporine level at 2 hours after administration in preoperative kidney transplant recipients for prediction of postoperative optimal cyclosporine dose.

OBJECTIVE: Absorption profiling of cyclosporine is a current concept of drug monitoring. A single blood concentration measurement 2 hours after cyclosporine administration (C2) has been shown to be a good predictor of drug exposure and clinical outcome. The recommendation states that achieving the recommended target level of 1700 +/- 340 ng/ml within 3-5 days after renal transplantation is associated with a lower rate of acute rejection and nephrotoxicity. The high variation of pharmacokinetic profile and short limited time during early post-transplantation period make it hard to adjust the cyclosporine dose that can reach that target level on time. The present study was designed to be a method to predict the optimal pre-transplant CsA dose. MATERIAL AND METHOD: Eleven living-related kidney transplant recipients were recruited to receive cyclosporine and were monitored for C2 concentration during the 2 weeks before operation by the designed method. The pre-transplant empirical dose of 3.5 mg/kg/dose every 12 hours were assigned to all patients. The first predicted dose was estimated by using C2 concentration of 1,700 ng/mL. The first predicted dose was prescribed to the patients. The second predicted dose was estimated by using C2 concentration of the first predicted dose. All patients received the average of the first and the second predicted doses of cyclosporine within 12-24 hrs before transplantation and until the 3rd day after transplantation. RESULTS: Nine out of 11 patients (81.81%) reached the target C2 level on the 3rd day after transplantation without any serious side effect and complications. The most common side effect was nausea and a flushing sensation that usually abated with a later dose after transplantation. CONCLUSION: The early postoperative optimal cyclosporine dose can be effectively predicted by pre-transplant C2 measurement as conducted in the present study.

The effectiveness of on-line hemodiafiltration on beta-2 microglobulin clearance in end stage renal disease.

OBJECTIVE: To compare beta2-microglobulin (beta2M) clearance between on-line hemodiafiltration (HDF) and high flux hemodialysis (HFHD). MATERIAL AND METHOD: The total, convection/diffusion, and membrane adsorption components of beta2M clearance in 10 hemodialysis patients treated with on-line HDF at the replacement fluid rates of 75 (HDF75) and 125 (HDF125) mL/min, were determined and compared with HFHD. RESULTS: The total beta2M clearance in the HDF 125 group was significantly higher than the HDF75 group (124.5 +/- 4.4 vs 101.3 +/- 4.1 mL/min; p < 0.05); both values were much greater than the HFHD group (p < 0.01). The convection/diffusion was the major portion of total beta2M clearance in all three groups. The values of convection/diffusion and membrane adsorption in both HDF groups were about 2 and 3 times, respectively, of the HFHD group (p < 0.01). Both components of beta2M clearance in the HDF125 group did not statistically differ from the HDF75 group, however; the value of convection/diffusion clearance in HDF125 was more than in the HDF75 group. Regarding Kt/Vurea and phosphate clearance, there were no significant differences among the study groups. CONCLUSION: On-line HDF could provide more beta2M clearance than HFHD by increasing both the convection/ diffusion, and membrane adsorption clearances. HDF125 provided more total beta2M clearance than HDF75 from the convection/diffusion mechanism while the adsorptive mechanisms were equal.

Target quantity for twice-a-week hemodialysis: the EKR (equivalent renal urea clearance) approach.

OBJECTIVE: The targets of dialysis per session, in terms of Kt/V and URR are well established for thrice-a-week hemodialysis (HD). The target values of these parameters could not be applied for the patients undergoing twice-a-week HD, which is performed in several developing countries. The equivalent renal urea clearance EKR (EKR [mL/min) = G (mg/min)/TAC (mg/mL)], which measures urea clearance in a continuous fashion, has been used in comparing amount of dialysis among the different modalities. For any chronic dialysis regimens the target EKRc, which was normalized to urea volume of distribution of 40 L, would be above 13 mL/min. Therefore, there is no data available regarding Kt/V, URR, and EKRc for twice-a-week HD. MATERIAL AND METHOD: The EKRc of 26 Thai patients treated with twice-a-week high flux HD were measured monthly for 12 months. The Kt/V, URR, and serum albumin were also measured monthly. RESULTS: Overall, the mean EKRc of 294 patient-month analysis was 11.68 +/- 0.16 mL/min. Monthly EKRc had a high correlation to Kt/V (r = 0.80) and URR (r = 0.82). When serum albumin was employed as a surrogate marker for treatment failure, ROC analysis revealed that EKRc above 13 mL/min had 90% and 100% probabilities to maintain monthly and 12-month serum albumin levels above 4 gm/dL, respectively. To obtain the target EKRc above 13 mL/min at 90 and 95% confidence, the values of Kt/V per session were 2.11 and 2.25, respectively while those of URR were 82.89 and 84.52%, respectively. CONCLUSION: For twice-a-week HD, to have the EKRc level above 13 mL/min, at 95% confidence, the Kt/V should exceed 2.2 and the URR should exceed 85% per session.

The clinicopathology and outcome of post-infectious glomerulonephritis: experience in 36 adults.

Post-infectious glomerulonephritis is one of the most common causes of acute glomerulonephritis. A retrospective study of post-infectious glomerulonephritis at King Chulalongkorn Memorial Hospital, Thailand was performed from January 1999 to December 2005. Among thirty six patients, eight cases were post-streptococcal glomerulonephritis and twenty eight cases were post non-streptococcal Glomerulo Nephritis (GN). Most cases present with edema, hypertension, gross hematuria and nephrotic-range proteinuria. C3 and CH50 commonly were low. Post-streptococcal glomerulonephritis had more aggressive pathology compared to the others. However the long term outcome was excellent. In the present study the authors found ESRD in only 14.3% (4 out of 28 cases) that reflects the excellent prognosis of post-infectious glomerulonephritis. Of interest, all of the ESRD patients were caused by post non-Streptococcal GN. Even though, no statistic was achieved; it might reflect the aggressiveness of non-Streptococcal pathogen.

Pharmacokinetics of sirolimus in Thai healthy volunteers.

Sirolimus, a novel immunosuppressive drug, has been used in kidney transplant recipients to minimize calcineurine inhibitor (CNI) and steroid toxicities. Likewise CNI, Sirolimus's pharmacokinetics have both inter and intra-individual pharmacokinetic variations. Due to ethnic differences, the recommended oral loading dose of 6 mg and oral maintenance dose of 2 mg per day for Caucasian patients and oral loading dose of 10 mg and oral maintenance dose of 5 mg per day for African-American patients may not be appropriate for Asian recipients. We, therefore conducted the pharmacokinetic study of sirolimus in Thai population, aimed to delineate the appropriate sirolimus dose for further clinical use. The study was performed in 12 healthy Thai volunteers. After an over night fasting, a single oral dose of 6 mg sirolimus was given. The complete pharmacokinetic study was done by UVhigh performance liquid chromatography (HPLC-UV) to measure the whole blood sirolimus level at 0.5 hour after the dose (C0.5) and then C1, C1.5, C2, C2.5, C3, C4, C6, C8, C12, and C24 hours. A complete area under the concentration time curve from 0-24 hours (AUC(0-24 hr)) was calculated by using the trapezoidal rule. The mean (+/- SD) time to maximal concentration (Tmax) was 1.45 +/- 0.5 hr (range 1-3 hrs). The maximal (Cm) and minimal plasma concentration (Ctroug) for sirolimus were 25.3 +/- 6.1 ng/ml (range 18.10 - 40 ng/ml) and 4.47 +/- 0.57 ng/ml (range 2.90 - 7.20) ng/ml respectively. The AUC(0-24 hr) were 187.9 +/- 48.2 ng * hr/ml (range 151.3 - 294.8 ng * hr/ml). Sirolimus level at 4 hr post-dose had the best of correlation with AUC(0-24 hr) (Pearson correlation = 0.76, p < 0.007). One volunteer had a very high sirolimus level. This subject's pharmacokinetic data showed AUC(0-24 hr) of 256 ng * hr/ml and Cmax of 40 ng/ml. In conclusion, the oral loading dose of 6 mg of sirolimus in Thai volunteers did not achieve the recommended therapeutic level (5-10 ng/ml) in most subjects. There are differences in pharmacokinetics of sirolimus between Thais and Caucasians.

Etiologies of glomerular diseases in Thailand: a renal biopsy study of 506 cases.

BACKGROUND: The nationwide renal registry has not yet been organized in Thailand, and the literature contains no registry of renal pathologic finding across the Southeast Asian (SEA) countries in the modern era when electron microscopy (EM) is routinely available. OBJECTIVE: The aim of the present study was to examine the prevalence of renal pathology in Thai population. MATERIAL AND METHOD: The authors reviewed the case file and renal biopsy specimens of King Chulalongkorn University Hospital to identify all adult native renal biopsy specimens received from January 2001 to December 2004, investigating prevalence and clinical and histological data. Biopsy of renal graft and in cases of trauma and tumors the authors excluded. Most of the biopsy specimens obtained The authorsre analyzed using light microscopy (LM), immunofluorescense (IF), and EM. Final diagnosis was made for each patient based on clinicopathologic correlations. RESULTS: A total of 506 native renal biopsies were processed during this period, 69.8% were female and 30.2% were male. Their age average was 37 +/- 14.2 (13-80) years. The most common indications for renal biopsy were nephrotic syndrome and SLE (36.8%, 34.5%, respectively), followed by asymptomatic hematuria/proteinuria in 10.9% of patients. Secondary glomerular diseases were dominant against primary diseases in all but elderly age group (>50 years), particularly LN. Among primary glomerular diseases, the prevalence of IgAN, focal segmental glomerulosclerosis, and membranous nephropathy were 31.0%, 24.9%, and 13.1%, respectively. The provisional clinical diagnosis was correct in three fourths (73.2%) of the SLE cases. Postbiopsy complications occurred in 3.3% (17/506). Gross hematuria was seen in 2.3% (12/506), and perinephric hemptoma in 0.79%. Three of them required blood transfusion but none of them died and required an invasive procedure for resolution. The major complications were 2 folds less than regular prevalence (0.6% compared to 1.3%). CONCLUSION: Although the data was collected from single center where EM is routinely performed, the authors believe that IgAN is the commonest primary GN in SEA countries. The authors are looking forward to seeing the nationwide registry data in Thailand and other SEA countries.