Disparity in utilization of combined kidney-liver transplantation in the United States.

BACKGROUND: Orthotopic liver transplantation (OLT) is performed as a definitive treatment of acute and chronic liver failure. The prevalence of acute and chronic kidney diseases is substantially higher in this population secondary to diverse etiologies. Combined kidney-liver transplantation (CKLT) is widely performed in some centers, even though there are no definitive studies which support or contradict this practice. METHODS: We comprehensively reviewed OLT as well as CKLT data from US transplant centers provided by United Network of Organ Sharing (UNOS). RESULTS: The incidence of CKLT as a percentage of total OLTs performed has been increasing, especially in the post-MELD era (2002 and after). Moreover, there is a great disparity among centers in regard to percentage of CKLTs to total OLTs. CONCLUSION: We conclude that there is much difference of opinion among US transplant centers as to indications for CKLT. A more scientific approach to this problem including studies to assess the role of kidney biopsy in determining renal outcome after OLT is needed.

Evaluation of proteinuria in healthy living kidney donor candidates.

BACKGROUND: Evaluation of living kidney donor candidates includes careful assessment for the presence or absence of kidney disease. Kidney donation has been considered to be at least relatively contraindicated if urinary total protein excretion is above the normal range. However, at the present time, there is no uniformly accepted level of urine total protein excretion that would exclude donation. Albumin excretion instead of total protein excretion as a criterion has not previously been evaluated. MATERIALS AND METHODS: This was a prospective observational study over a 3-year period in a single tertiary care center designed to assess current selection criteria for kidney donation with respect to urine total protein and albumin excretion. RESULTS: Twenty four percent (25 of 105) of healthy adult kidney donor candidates had elevated urinary total protein excretion rates (150 to 292 mg/24 h). Of these 105 candidates, 39 had simultaneous measurements of both urinary total protein and albumin. Although one-third (13/39) had elevated 24-hour urine total protein values, none had elevated urine albumin excretion. CONCLUSION: Measurement of albumin, the most common single protein found in urine, appears to be helpful in the evaluation of proteinuria in donor candidates. Many healthy adult kidney donor candidates have mildly elevated total protein excretion but normal albumin excretion. We believe that such patients should not be excluded from donation.

Paecilomyces peritonitis: case report and review of the literature.

While filamentous fungi are a rare cause of peritonitis in peritoneal dialysis patients, there is increasing recognition of Paecilomyces species as pathogens in such patients. We herein report a case of fungal peritonitis secondary to the filamentous Paecilomyces variotii species. The patient had a long and ultimately fatal course of illness despite catheter removal, discontinuation of peritoneal dialysis, recurrent intraabdominal abscess drainage, and prolonged courses of antifungal therapy. Our experience with this case and a review of the literature suggests that infection with this fungus can cause substantial morbidity and is probably best treated with prompt catheter removal, aggressive antifungal therapy and vigilant observation for complications.

High glucose decreases matrix metalloproteinase-2 activity in rat mesangial cells via transforming growth factor-beta1.

Diabetic nephropathy is characterized by accumulation of mesangial matrix. Glucose-induced inhibition of matrix-degrading enzymes such as collagenases is believed to contribute to matrix accumulation. We have previously demonstrated that 72 kDa type IV collagenase activity is decreased in the rat mesangial cells cultured in high glucose media [Diabetes 1995;44:929-935]. The present studies were designed to investigate if the cytokine transforming growth factor-beta1 (TGF-beta1) mediates this effect of glucose. Type IV collagenases degrade type IV collagen as well as gelatin (denatured collagen) and are thus also called gelatinases. They belong to the family of matrix metalloproteinases (MMPs); MMP activity is controlled by tissue inhibitors of metalloproteinases (TIMPs). The activity of 72 kDa type IV collagenase, also known as matrix metalloproteinase-2 (MMP-2), was assessed using three methods: (1) fluoresceinated gelatin degradation assay to detect free enzyme activity (activity which is present in excess of TIMP-inhibited activity); (2) zymography to measure total (free + TIMP-bound) enzyme activity; (3) ELISA using specific antibodies to measure MMP-2 levels. TGF-beta1 and TIMP-2 levels were also determined by ELISA. Incubation of primary cultures of rat mesangial cells for 5 days in 30 vs. 5 mM glucose resulted in a 3-fold increase in production of total TGF-beta1, a significant decrease in MMP-2 activity and immunoreactive MMP-2 levels, and an increase in TIMP-2 levels. Addition of exogenous TGF-beta1 to mesangial cells incubated in 5 mM glucose replicated the high glucose effect by producing a significant decrease in MMP-2 levels with a concurrent increase in TIMP-2 levels. Furthermore, glucose-induced inhibition of MMP-2 activity was completely blocked by neutralization of TGF-beta1 with anti-TGF-beta1 antibody. We conclude that the decrease in MMP-2 activity induced by glucose loading is mediated via TGF-beta1.

Transjugular renal biopsy in patients with liver disease.

Although transjugular renal biopsy has been used extensively in Europe, experience with its use in the United States has been limited. We report 25 patients who underwent both transjugular liver and renal biopsies in the same sitting and 4 patients who underwent only a transjugular renal biopsy. All 29 patients had both liver disease and renal abnormalities. Each patient was also believed to have a relative or absolute contraindication to a percutaneous renal biopsy (usually in the form of a bleeding abnormality). Transjugular renal biopsy yielded a quantity of tissue sufficient for diagnosis in all but 1 patient. The mean number of glomeruli obtained per biopsy was 19.4 +/- 12.2 (SD). Pathological diagnoses found were tubular injury in 5 patients, membranoproliferative glomerulonephritis in 5 patients, nephrosclerosis in 3 patients, diabetic nephropathy in 2 patients, immunoglobulin A (IgA) nephropathy in 2 patients, minimal change disease in 2 patients, end-stage renal disease in 2 patients, nonspecific changes in 1 patient, early glomerulosclerosis in 1 patient, tubular atrophy only in 1 patient, and normal renal histological characteristics in 4 patients. One patient with suspected IgA nephropathy had no histological diagnosis established because of a lack of glomeruli in the biopsy specimen. There were no instances of major bleeding from the perirenal area; however, a small perirenal hematoma was identified in 3 patients by postbiopsy computed tomography or sonography. Thus, based on our experience, transjugular renal biopsy appears to be a safe and effective procedure for establishing a histological diagnosis and is an attractive alternative biopsy method for patients with advanced liver disease and contraindications to conventional percutaneous renal biopsy.

Metabolic alkalosis in a hemodialysis patient after ingestion of a large amount of an antacid medication.

A maintenance hemodialysis patient developed metabolic alkalosis in the absence of vomiting or nasogastric suction. The cause of the metabolic alkalosis was ingestion of an exogenous alkali in the form of Bromoseltzer. The metabolic alkalosis improved with hemodialysis using a low-bicarbonate bath.

Management of hypophosphatemia induced by high-flux hemodiafiltration for the treatment of vancomycin toxicity: intravenous phosphorus therapy versus use of a phosphorus-enriched dialysate.

Intensive high-flux hemodiafiltration is often used in the management of vancomycin toxicity. We describe two patients who developed hypophosphatemia as a consequence of this form of therapy. The first patient was treated with an intravenous phosphorus infusion. For the second patient, hypophosphatemia was corrected, during hemodiafiltration, with the use of a phosphorus-enriched dialysate. The latter dialysate was prepared by adding sodium phosphate salts to the "base concentrate" of a dual-concentrate, bicarbonate-based dialysate delivery system. This simple method was more efficient than intravenous therapy in ameliorating the hypophosphatemia secondary to aggressive hemodiafiltration treatment.

Role of angiotensin II in diabetic nephropathy.

Considerable evidence suggests that the intrarenal renin-angiotensin system plays an important role in diabetic nephropathy. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II (Ang II) receptor blockers (ARBs) can attenuate progressive glomerulosclerosis in disease models and can slow disease progression in humans. Because agents that interfere with Ang II action may decrease glomerular injury without altering glomerular pressures, it has been suggested that Ang II has direct effects on glomerular cells to induce sclerosis independent of its hemodynamic actions. To study nonhemodynamic effects of Ang II on matrix metabolism, many investigators have used cell culture systems. Glucose and Ang II have been shown to produce similar effects on renal cells in culture. For instance, incubation of mesangial cells in high-glucose media or in the presence of Ang II stimulates matrix protein synthesis and inhibits degradative enzyme (e.g., collagenase, plasmin) activity. Glucose and Ang II also can inhibit proximal tubule proteinases. Glucose increases expression of the angiotensinogen gene in proximal tubule cells and Ang II production in primary mesangial cell culture, which indicates that high glucose itself can activate the renin-angiotensin system. The effects of glucose and Ang II on mesangial matrix metabolism may be mediated by transforming growth factor-beta (TGF-beta). Exposure of mesangial cells to glucose or Ang II increases TGF-beta expression and secretion. Their effects on matrix metabolism can be blocked by anti-TGF-beta antibody or ARBs such as losartan, which also prevents the glucose-induced increment in TGF-beta secretion. Taken together, these findings support the hypothesis that the high-glucose milieu of diabetes increases Ang II production by renal, and especially, mesangial cells, which results in stimulation of TGF-beta secretion, leading to increased synthesis and decreased degradation of matrix proteins, thus producing matrix accumulation. This may be an important mechanism linking hyperglycemia and Ang II in the pathogenesis of diabetic nephropathy.

Removal of Foscarnet by hemodialysis using dialysate-side values.

Foscarnet is an antiviral agent widely used in the treatment of cytomegalovirus (CMV) infection. We describe a cardiac transplant patient, who while being maintained with hemodialysis because of tobramycin-induced acute renal failure, was given Foscarnet for disseminated CMV infection. Using dialysate-side clearance methodology, we found the dialyzer clearance of Foscarnet to be in the order of 89 ml/min.

Saline-induced dilutional acidosis in a maintenance hemodialysis patient.

A patient with end-stage renal disease developed severe hyperchloremic acidosis (venous serum total CO2 level of 10 mmol/L) after treatment with 16 L of isotonic saline. Analysis of this case and published literature indicates that dilutional acidosis may result when very large volumes of isotonic saline are administered intravenously, especially in patients with impaired or absent renal function.

Role of angiotensin II in glucose-induced inhibition of mesangial matrix degradation.

Accumulation of mesangial matrix in diabetic nephropathy is caused by increased synthesis and decreased degradation. We have previously demonstrated that incubation in high-glucose medium decreases mesangial cell collagenase activity (Diabetes 44:929-935, 1995). Because angiotensin II (AII) is involved in the pathogenesis of diabetic nephropathy, the present studies were performed to determine if AII mediates glucose-induced 1) inhibition of mesangial collagenase activity, 2) mesangial matrix accumulation, and 3) in-crease in transforming growth factor (TGF)-beta1 secretion in mesangial cells. The direct effect of high glucose on AII generation in mesangial cells was also determined. Primary mesangial cells from normal Sprague-Dawley rats were used in all studies. Collagenase activity in cell medium was determined using three methods: 1) zymography; 2) quantitative assay using fluoresceinated gelatin as substrate; and 3) a new enzyme-linked immunosorbent assay (ELISA) that specifically measures 72-kDa collagenase (MMP-2), the principal collagenase synthesized by mesangial cells. Matrix accumulation was estimated by immunoperoxidase assay on cell layers using anti-glomerular basement membrane (GBM) antibodies. TGF-beta1 and AII levels were determined by ELISA. Exposure of mesangial cells to 30 mmol/l glucose (high glucose) vs. 5 mmol/glucose (normal glucose) for 5 days resulted in a significant decrease in collagenase activity (25%) that was normalized by 10(-4) mol/l losartan, a type 1 angiotensin II (AT1) receptor antagonist. High glucose increased anti-GBM binding compared with normal glucose; this effect of glucose was reversed by losartan. Incubation of cells with 30 mmol/l glucose increased total TGF-beta1 secretion, which was also normalized by losartan. Addition of AII (10(-6) mol/l) for 24 h to the culture medium inhibited collagenase activity by 33%; losartan (10(-4) mol/l) blocked this inhibition of enzyme activity. Also, AII decreased collagenase (MMP-2) levels but stimulated TGF-beta1 secretion in mesangial cells. Finally, glucose increased mesangial AII generation in a concentration-dependent manner, with incubation in 30 mmol/l glucose increasing AII by 25% compared with 5 mmol/l glucose. We conclude that glucose increases AII production by mesangial cells, which results in stimulation of TGF-beta1 secretion, decreased matrix degradation, and increased matrix accumulation. These effects of AII are mediated by the AT1 receptor.

Decreased glomerular proteinase activity in the streptozotocin diabetic rat.

Decreased glomerular proteinase activity may contribute to matrix accumulation in diabetes. Male Sprague-Dawley rats were rendered diabetic by injection of streptozotocin (STZ) 65 mg/kg i.v.; age-matched, sham-injected rats served as controls. Glomeruli from diabetic rats 1 month after STZ injection demonstrated significant decreases in collagenase and cathepsin B activities compared to control glomeruli. Treatment with insulin resulted in a slight (but not significant) increase in collagenase activity and normalized cathepsin B activity. We conclude that decreased glomerular collagenase and cathepsin B activities are present in STZ diabetes. These alterations may contribute to mesangial matrix accumulation.

Hemodialysis-induced hypophosphatemia in a normophosphatemic patient dialyzed for ethylene glycol poisoning: treatment with phosphorus-enriched hemodialysis.

Hypophosphatemia developed in a normophosphatemic patient after 9 h of hemodialysis therapy (using a phosphate-free dialysate) administered for the treatment of ethylene glycol poisoning. The hypophosphatemia was promptly improved with additional hemodialysis treatment using a phosphorus-enriched dialysate.

Use of a phosphorus-enriched hemodialysate to prevent hypophosphatemia in a patient with renal failure-related pericarditis.

We describe a patient who suffered from renal failure-associated pericarditis and underwent daily 3.5-hour hemodialysis treatments for 17 days. The initially elevated serum phosphorus level gradually fell to below normal on days 11 and 12 as a result of the intensive dialytic therapy. Phosphorus was added to the "base concentrate" of a dual-concentrate, bicarbonate-based dialysate delivery system on days 13 to 17. Because of this phosphorus-enrichment, we were able to maintain the patient's serum phosphorus levels within normal limits in spite of continued daily dialysis treatments.

Treatment of acute methanol intoxication with hemodialysis using an ethanol-enriched, bicarbonate-based dialysate.

A patient poisoned with methanol was successfully hemodialyzed with an ethanol-enriched, bicarbonate-based dialysate. Along with a concomitant intravenous infusion of ethanol, the ethanol-enriched dialytic procedure was able to maintain an intradialytic plasma ethanol level of 80 to 102 mg/dL. The patient recovered without any sequelae of methanol intoxication.

Correction of hypercalcemia and hypophosphatemia by hemodialysis using a conventional, calcium-containing dialysis solution enriched with phosphorus.

We report a woman with hypercalcemia and hypophosphatemia due to primary hyperparathyroidism. Hemodialysis using a phosphorus-enriched, conventional, calcium-containing dialysis solution resulted in the simultaneous correction of hypercalcemia and hypophosphatemia, resulting in a marked improvement of the patient's impaired mental status.