Taku Kim

Serum hepatocyte growth factor levels in patients with chronic renal failure.

The serum levels of hepatocyte growth factor (HGF) were determined in chronic renal failure (CRF) patients. Nondialysis patients with renal insufficiency had significantly higher serum HGF than normal subjects (0.34 +/- 0.10 ng/ml, n = 21 vs. 0.19 +/- 0.05 ng/ml, n = 15; p < 0.001), and the elevated serum HGF correlated with their serum creatinine levels. Hemodialysis (HD) patients treated for 5-10 years showed higher serum HGF than those receiving HD for 1 year or less (0.45 +/- 0.14 ng/ml, n = 8 vs. 0.33 +/- 0.11 ng/ml, n = 9; p < 0.05). Continuous ambulatory peritoneal dialysis patients also showed elevated serum HGF levels comparable to those of HD patients. There was no difference in serum HGF levels in HD patients with or without acquired cystic disease of kidney. Consequently, serum HGF is elevated in CRF, which may be attributed to the increased production of HGF in response to the chronic renal injury, the effect of heparin, or reduced removal of serum HGF in CRF patients.

Desensitization Protocol in Highly HLA-Sensitized and ABO-Incompatible High Titer Kidney Transplantation

BACKGROUND A positive crossmatch indicates the presence of donor-specific alloantibodies and is associated with a graft loss rate of >80%; anti-ABO blood group antibodies develop in response to exposure to foreign blood groups, resulting in immediate graft loss. However, a desensitization protocol for highly HLA-sensitized and ABO-incompatible high-titer kidney transplantation has not yet been established. METHODS We treated 6 patients with high (≥1:512) anti-A/B antibody titers and 2 highly HLA-sensitized patients. Our immunosuppression protocol was initiated 1 month before surgery and included mycophenolate mofetil (1 g/d) and/or low-dose steroid (methylprednisolone 8 mg/d). Two doses of the anti-CD20 antibody rituximab (150 mg/m(2)) were administered 2 weeks before and on the day of transplantation. We performed antibody removal with 6-12 sessions of plasmapheresis (plasma exchange or double-filtration plasmapheresis) before transplantation. Splenectomy was also performed on the day of transplantation. Postoperative immunosuppression followed the same regimen as ABO-compatible cases, in which calcineurin inhibitors were initiated 3 days before transplantation, combined with 2 doses of basiliximab. RESULTS Of the 8 patients, 7 subsequently underwent successful living-donor kidney transplantation. Follow-up of our recipients showed that the patient and graft survival rates were 100%. Acute cellular rejection and antibody-mediated rejection episodes occurred in 1 of the 7 recipients. CONCLUSIONS These findings suggest that our immunosuppression regimen consisting of rituximab infusions, splenectomy, plasmapheresis, and pharmacologic immunosuppression may prove to be effective as a desensitization protocol for highly HLA-sensitized and ABO-incompatible high-titer kidney transplantation.

A novel approach to successful ABO-incompatible high-titer renal transplantation.

BACKGROUND Currently the long-term outcome among recipients of ABO-incompatible renal transplantations is excellent in Japan. However, previous reports have documented poor outcomes in patients with high (> 1:256) anti-A/B antibody titers pretreatment. The immunosuppressive protocol for ABO-incompatible high-titer renal transplantation has remained a medical challenge. METHODS We treated 3 patients with high (> 1:512) anti-A/B antibody titers prior to ABO-incompatible renal transplantation. Our immunosuppressive protocol was initiated 1 month prior to surgery and included mycophenolate mofetil (1 g/d) and low-dose steroid (methylprednisolone [8 mg/d]). Two doses of the anti-CD20 antibody rituximab, (150 mg/m2) were administered 2 weeks before and on the day of transplantation. We performed antibody removal with 6 to 8 sessions of plasmapheresis (plasma exchange or double-filtration plasmapheresis) before transplantation. Splenectomy was also performed on the day of transplantation. Postoperative immunosuppression followed the same regimen as ABO-compatible cases, in which calcineurin inhibitors were initiated 3 days before transplantation combined with 2 doses of basiliximab. RESULT With this protocol, the anti-A/B antibody was reduced to below 1:16 in all cases. All 3 patients underwent successful transplantation with a mean current serum creatinine of 1.32 mg/dL (range, 1.22-1.50 mg/dL). There were no episodes of antibody-mediated rejection. No serious complications or side effects were encountered. CONCLUSIONS A preconditioning protocol consisting of rituximab infusions, splenectomy, plasmapheresis, and pharmacologic immunosuppression enabled ABO-incompatible renal transplantation in patients with high (> 1:512) anti-A/B antibody titer.

Hepatocyte Growth Factor in Glycerol-induced Acute Renal Failure

Hepatocyte growth factor (HGF) facilitates the regeneration of injured kidney in acute renal failure (ARF). Here we investigated the HGF production in glycerol-induced ARF rats. HGF mRNA expression levels were elevated in liver, spleen, and lung 6-24 h after glycerol injection. Tissue HGF protein levels determined by an enzyme-linked immunosorbent assay also increased in liver and spleen, whereas they decreased in the injured kidney 24 h after injection. Immunohistochemical studies showed that the number of HGF-producing cells did not increase in the liver. HGF receptor/c-Met mRNA levels were elevated only in the kidney. These results indicate that HGF supplied in an endocrine manner may play an important role in the regenerating process following ARF.

Low-grade albuminuria reduction with angiotensin II type 1 receptor blocker in renal transplant recipients.

BACKGROUND Microalbuminuria, defined as urine albumin to urine creatinine ratio of 30 to <300 mg/g, is an established risk factor for cardiovascular morbidity and mortality in the general population. Low-grade albuminuria (<30 mg/g) is considered a marker for subclinical vascular damage that predisposes to future cardiovascular diseases and death. Lowering urinary albumin excretion reduces the risk of cardiovascular disease. Our study was designed to evaluate the influence of angiotensin II type 1 receptor blocker (ARB) in normotensive renal transplant recipients with low-grade albuminuria. PATIENTS AND METHODS Our 6-month prospective observation study used a randomized control and open-label design as we examined the effects of an ARB (valsartan) on blood pressure, urinary albumin excretion, hematocrit, serum potassium and estimated glomerular filtration rate (eGFR) in normotensive recipients with allografts of more than 1 year. A total of 35 renal transplant recipients were enrolled in this study. Patients were randomly assigned to 2 groups: ARB group (n=18), receiving 40-80 mg valsartan daily for 6 months, and the control group (n=17). RESULTS In the ARB group, urine albumin excretion was significantly reduced from 25.9 ± 19.1 mg/g to 12.0 ± 9.6 mg/g at 6 months after administration. eGFR decreased slightly at 6 months after administration. However, no patients undergoing treatment for adverse effects required discontinuation of ARB. CONCLUSIONS This study reveals that ARB is safe and reduces low-grade albuminuria in normotensive renal transplant recipients. Thus, early treatment of ARB in recipients with low-grade albuminuria may prevent cardiovascular disease after renal transplantation.

Kidney Transplants from LivingRelated Donors Having Double Inferior Vena cava

We performed four living related kidney transplantations from donors with double inferior vena cava (D-IVC), in which the left kidney was selected in two cases and the right in two cases. By dissecting the right internal iliac vein and isolating the right external iliac vein, the surgical procedure of the recipient side was so devised as to avoid any complications. In one patient, the surgical procedure of the donor side was modified to extend the donor left renal vein by anastomosis of part of the donor IVC to the renal vein. In the other case, no special treatment was necessary due to the patient’s slender physique. In all four cases, transplants were successfully performed. The following conclusions can be made from these results: If the donor has D-IVC, it is essential to carefully conduct pre-operative examinations including angiography and venography to investigate other possible anomalies and blood flow of the renal vein. In addition, the graft must be carefully selected so that it is not disadvantageous to the donor. If there is no disadvantage to the donor as to which kidney is selected, the kidney with the longer renal vein should be transplanted.

Cardiac Output, Renal Blood Flow and Hepatic Blood Flow in Rats with Glycerol-Induced Acute Renal Failure

Cardiac output (CO), renal blood flow (RBF) and hepatic blood flow (HBF) were measured by the microsphere method before (control) and at 4 and 10 h after the induction of acute renal failure by intramuscular injection of glycerol in water-drinking, long-term saline-drinking and long-term captopril (converting enzyme inhibitor)-drinking rats. At 4 h after glycerol injection, CO, RBF and HBF significantly decreased in all three groups. At 10 h after glycerol injection, CO, RBF and HBF recovered to 88% of the respective control levels in only the saline-drinking rats, whereas CO, RBF and HBF further decreased to 53, 38 and 58% of the control levels, respectively in the captopril-drinking rats. At this time, not only acute renal failure but also hepatic disorder developed in the water-drinking and captopril-drinking rats as indicated by elevations of serum creatinine, urea nitrogen, alanine aminotransferase and other blood chemistry levels. The development of acute renal failure was not suppressed by captopril, but by long-term saline load. Thus, we conclude that the decrease in CO is an important variable of the early decrease in renal and hepatic perfusion in glycerol-induced acute renal failure, and that the early recovery of HBF as well as RBF may play an important role in preventing the development of acute renal failure.

Production and activation of hepatocyte growth factor in acute renal failure.

Hepatocyte growth factor (HGF) facilitates the regeneration of injured kidney in acute renal failure (ARF). HGF is produced as a single-chain precursor by cells of mesenchymal origin and is converted to a biologically active, heterodimeric molecule by proteol ytic processing. We studied HGF mRNA and protein levels in systemic organs of glycerol-induced ARF rats, a model of crush syndrome. HGF protein concentration of tissue homogenate was measured by ELISA. Both mRNA and protein levels were increased in liver and spleen at 24 hours after the glycerol injection whereas HGF protein level was decreased in the injured kidney. Expression of HGF receptor/c-met mRNA was elevated only in the kidney. These results suggest that HGF supplied in an endocrine manner may play an important role in the regenerating process following ARF. Next, we measured serum HGF concentration by ELISA in 8 ARF patients caused by crush syndrome and the molecular size of serum HGF was determined byimmun oblotting. Although serum HGF levels elevated in all patients, the HGF levels did not associate with their prognoses. While a single-chain molecule was predominantly observed in sera from chronic renal failure patients and healthy subjects, the majority of serum HGF was a heterodimeric form in 7 ARF patients. In one patient who developed disseminated intravascular coagulation syndrome and had a poor prognosis, a single-chain molecule was predominant although the serum HGF concentration was equivalent. These data suggest that the activity of proteolytic processing may be also an important factor for the expression of the biological function of HGF.

Cadaveric Renal Transplantation from a Non-Heart-Beating Pediatric Donor into Adult Recipients

Introduction: The use of cadaveric pediatric kidneys has been suggested as a means to overcome organ shortage, but is debated because of technical complications and an increased incidence of functional allograft impairment. Methods: We experienced 2 cases of cadaveric renal transplantation from a non-heart-beating pediatric donor. Results: In our cases, transplanted kidneys achieved good graft function and proteinuria due to glomerulosclerosis was not recognized. Conclusion: Previous reports indicate that in transplantation from pediatric donors into adults recipients, glomerular sclerosis occurs as the reason for impairment of grafts. Further, cadaveric renal transplantation from a non-heart-beating donor has a warm ischemia time and an increased risk of hyperfiltrated injury and graft failure. If transplantation of pediatric kidneys into adults from a non-heart-beating donor is performed, BMI and BSA must be carefully considered in the selection of recipients in order to avoid imbalance between nephron supply and metabolic demands and to insure successful, healthy grafts.

Pharmacokinetic study of interleukin-2 following intravenous injection in hemodialysis patients with renal cell carcinoma.

Abstract:  The purpose of the present study is to determine the change in blood concentration of interleukin‐2 (IL‐2) after intravenous injection in hemodialysis patients and to assess its safety. Four hemodialysis patients who underwent nephrectomy due to renal cell carcinoma were treated with IL‐2 at a dose of 350 000–700 000 JRU by intravenous injection. Pharmacokinetic parameters were analyzed from the serum IL‐2 concentration, which reached its peak just after the end of infusion, followed by biphasic elimination, and was below the detection limit in all patients at 24 h postinfusion. In comparison with patients with normal renal function, the volume of distribution in the serum compartment was almost comparable (3820 ± 2020 mL). Clearance (50.47 ± 11.50 mL/min) decreased to 40%, and the half‐life of the distribution phase (0.45 ± 0.19 h) and that of the terminal phase (1.72 ± 0.20 h) were distinctly longer. The area under the blood concentration–time curve was about two‐fold higher than that of non‐hemodialysis patients. In all patients, there were no serious adverse reactions. The results of the present study suggest that intravenous IL‐2 therapy can be safely performed in hemodialysis patients.