Successful renal transplantation in hyperoxaluria. A report of two cases

Two patients with documented primary hyperoxaluria have received renal allografts with successful function for 10 years and 25 months. The patient in case 1 required a ureterolithotomy 6 years post-transplantation to remove a renal calculus of calcium oxalate. This case illustrates that despite recurrence of oxalate stones in the allograft, satisfactory renal function can be maintained by careful follow-up and appropriate interventions. Factors that may be important in successful graft function include the occurrence of acute rejection episodes, avoidance of ischemic graft damage, trials of pyridoxine therapy to decrease oxalate excretion, and frequent evaluation with appropriate interventions as necessary. Renal transplantation is a suitable and possibly the preferred form of therapy of end stage renal disease in patients with primary hyperoxaluria.

Effects of NaCl on renin and aldosterone responses to potassium depletion

We have previously suggested that renin secretion is inversely related to the magnitude of absorptive chloride transport in the thick ascending limb of the loop of Henle. Potassium depletion inhibits chloride transport at this site in the nephron. Consequently, we studied the effects of varying sodium and chloride intakes on the renin and aldosterone responses to potassium depletion. Potassium depletion prevented suppression of plasma renin activity (PRA) by dietary NaCl loading and augmented the PRA response to NaCl deprivation. PRA was stimulated (P less than 0.01) by selective chloride (without sodium) deprivation, and potassium depletion did not augment this response. Potassium depletion did not interfere with suppression of PRA by albumin-induced volume expansion. Plasma aldosterone was suppressed by potassium depletion, and the effect of potassium depletion on aldosterone was augmented by NaCl deprivation. In conclusion, the magnitude of PRA stimulation and aldosterone suppression by potassium depletion is modulated by dietary NaCl intake. The results are consistent with the hypothesis that potassium depletion stimulates renin release by inhibiting chloride transport in the loop of Henle.

Effect of pretransplant stored donor-specific blood transfusions on early renal allograft survival in one-haplotype living related transplants

The effect of pretransplant stored donor-specific blood transfusions (DSBTs) on early renal allograft survival in 37 consecutive one-haplotype living related donor (LRD) transplants (group B) was compared with a similar consecutive series of 38 one-haplotype LRD recipients (group A) who did not receive DSBTs. All transplant recipients in both groups were treated with identical immunosuppressive protocols using azathioprine and prednisone. Forty patients received pretransplant DSBTs and three of these patients (8%) developed cytotoxic antibodies to their prospective donors. Neither hyperacute rejection nor hepatitis occurred in group B patients following DSBTs. One group B patient experienced a technical graft loss on the 1st postoperative day and was excluded from the rejection data. Graft survival at 3 and 6 months was 100 and 90% in group B recipients and 68% in group A recipients. All 12 group A graft failures resulted from acute nonreversible rejection episodes occurring during the first 3 months post-transplant. The three group B graft failures occurring at 6 months were attributable to chronic vascular rejection. Chronic rejection of the renal allograft was histologically documented in six group A and five group B patients by 6 months post-transplant. The use of stored donor blood offered a simple and easily monitored method of administering pretransplant DSBTs that was convenient to the donor and recipient. The administration of DSBTs did not appear to be harmful to the recipient. In fact, the use of pretransplant stored DSBTs in one-haplotype LRD renal transplantation appeared to improve the prospects of early graft survival in our experience.

Effect of alternate-day prednisone on plasma lipids in renal transplant recipients

While numerous groups have reported high prevalences of plasma lipid abnormalities in their renal transplant recipients, we have been unable to confirm this finding. We have suggested that the routine use of alternate-day steroids (ADS) in our patients may be responsible. To test that hypothesis, a prospective controlled trial of equal total dose ADS versus daily steroids (DS) was conducted. Four months after transplant and before entering the trial, transplant study patients had significantly higher serum cholesterol (243 +/- 9 mg/dl) than either normal controls (cholesterol 200 +/- 7 mg/dl, alpha = 0.01) or hemodialysis patients (cholesterol 211 +/- 9 mg/dl, alpha = 0.01). They also had higher serum triglyceride than controls (129 +/- 7 mg/dl vs. 98 +/- 8 mg/dl, alpha = 0.01). After randomization to DS or ADS and 1 year of further followup study, the ADS group had a significant decrease in both serum triglyceride (139 +/- 9 to 100 +/- 7 mg/dl, P less than 0.01) and cholesterol (251 +/- 16 to 220 +/- 9 mg/dl, P less than 0.05) while the DS group's serum triglyceride and cholesterol values remained unchanged. Serum triglyceride and cholesterol in the ADS group had decreased to values that were not significantly different from 41 normal healthy controls. Dose spacing per se, and not the use of a lower total dose of prednisone, appears to result in a lower prevalence of abnormal plasma lipids after successful renal transplantation.

Influence of aortic constriction on proximal chloride reabsorption during volume expansion

Extracellular fluid volume expansion is associated with a decrease in the transepithelial chloride gradient in the proximal convoluted tubule. We have previously shown that this effect occurs in the presence of hypo- or hyperchloremia and is not dependent on a change in filtered chloride or bicarbonate load. To determine the influence of filtered fluid load on this effect of volume expansion, micropuncture studies were carried out during acute extracellular fluid volume expansion in rats with (group AC) and without (group CON) a reduction in renal perfusion pressure. Delayed aortic constriction prevented the increase in fluid load (49.7 +/- 2.4 and 49.0 +/- 3.9 nl/min for hydropenia and volume expansion, respectively), but reduced tubule fluid to plasma inulin ratios (2.25 +/- 0.13 and 1.84 +/- 0.8) were maintained. Tubule fluid to plasma chloride ratios did not change in group AC (1.27 +/- 0.03 and 1.25 +/- 0.01) as compared to group CON (1.25 +/- 0.02 and 1.18 +/- 0.02; p less than 0.05). Fractional chloride reabsorption fell in both groups. Absolute chloride reabsorption was highly correlated (p less than 0.001) with absolute fluid reabsorption. These results suggest that filtered fluid load or some related variable is an important determinant of the generation of the chloride gradient in the proximal tubule.

Quantitative urinary protein excretion in chronic renal failure

The diagnostic value of the measurement of quantitative proteinuria in patients with a creatinine clearance of less than 10 ml/min was determined in patients seen in a single center over a 5-year period. All 126 patients in whom a definitive renal diagnosis was possible were included. Patients with glomerular disease excreted 6.1 +/- 0.6 g/day and patients with interstitial disease 1.5 +/- 0.3 g/day (p less than 0.001). In individual patients with end-stage renal disease, however, measurement of urinary protein excretion excluded (with 95% confidence levels) patients with interstitial diseases only when greater than 2.9 g/day. To examine the natural history of proteinuria in progressive renal disease, urinary protein, absolute and factored for glomerular filtration rate (GFR; creatinine clearance), was determined at 10 ml/min decrements in GFR for patients with membranoproliferative glomerulonephritis, idiopathic membranous glomerulonephritis and focal glomerulosclerosis. Quantitative urinary protein excretion was relatively constant as GFR fell but did fall significantly at less than 10 ml/min but only to 4.8-7.0 g/day at even that level. Urinary protein excretion/GFR increased as GFR fell, particularly at end stage where a highly significant four-fold rise was seen; an increase also occurred in patients with primary interstitial disease. Similar data were obtained for 34 randomly selected patients after at least 1 year of chronic hemodialysis. Although a significant decline in absolute urinary protein excretion occurred during the year of dialysis to levels not different between glomerular and interstitial disease, urinary protein excretion/unit GFR remained elevated. Increased urinary protein excretion/unit GFR may result from a functional adaptation of remaining nephrons in response to declining renal mass.

Hereditary thrombotic thrombocytopenic purpura: microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency occurring in consecutive generations

Microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency occurred in a mother an daughter when each was in her third decade. The mother had prominent neurological findings, fever, and expired from renal insufficiency. Her daughter's only major symptom was renal insufficiency. The similarity of the mother's illness to thrombotic thrombocytopenic purpura and of the daughter's to adult hemolytic uremic syndrome suggests that these diseases are variants of a single clinical disorder, while their occurrence in direct descendents strengthens the postulate that in selected instances a genetic predisposition to these disorders may be important.

Comparison of daily and alternate-day prednisone during chronic maintenance therapy: a controlled crossover study

To determine if dose spacing of low dose chronic suppressive corticosteroid therapy would result in different effects on circulating T lymphocytes and hypothalamic-pituitary-adrenal (HPA) axis suppression, a crossover trial of two maintenance steroid regimens was performed. Twenty stable renal allograft recipients were treated for 6 mo with daily prednisone (DS) and then the same patients were abruptly converted to alternate-day prednisone (ADS) for another 6 mo. Total prednisone dosage was identical during the 6-mo study periods and only dose spacing differed. Both circulating T lymphocyte numbers and responsiveness to mitogens were less on the DS regimen. Patients gained weight on DS and lost weight on ADS. Five of the 20 patients developed infections on DS. However, HPA suppression was not different on the two regimens. These findings suggest that dose spacing alters the immunosuppressive and metabolic response to prednisone, even at low dose.

Effect of hypochloremia on loop segment chloride and solute reabsorption in the rat during volume expansion

Hypochloremia has been associated by inference from clearance studies with disturbances in free water reabsorption and renal renin release by a macula densa mechanism. To examine directly these relationships, we studied chloride, fluid, and solute transport in the loop segment (LS) of rat superficial nephrons by micropuncture techniques following acute volume expansion with 0.15 m sodium chloride (CVE) or sodium bicarbonate (BVE). Plasma renin activity was suppressed in group CVE but not in group BVE. Blood pressure, plasma volume expansion, whole kidney GFR, urinary sodium excretion, late proximal and early distal SNGFR, and fluid delivery to the LS were no different between groups CVE and BVE despite different plasma chloride concentrations (102 +/- 5 mEq/liter for CVE vs. 74 +/- 3 for BVE; P less than 0.001). Absolute LS chloride reabsorption was less in BVE than it was in CVE (2030 +/- 120 pEq/min vs. 2454 +/- 136; P less than 0.025). This was associated with significantly lower fractional absolute LS solute reabsorption and higher early distal tubule fluid osmolality. These data demonstrate directly and in vivo that a decrease in chloride reabsorption in the LS of superficial nephrons is associated with impaired solute reabsorption in that segment and a failure to suppress plasma renin activity by sodium loading.

Surgical therapy for persistent hypertension after renal transplantation

The presence of the original diseased native kidneys in renal allograft recipients is associated with an increased prevalence of persisting post-transplant hypertension. In 9 of 10 such transplant patients bilateral nephrectomy of these native kidneys, performed at least 1 year after successful transplantation of a renal allograft, resulted in improved blood pressure control. Although these 10 patients had higher peripheral plasma renin activity (PRA) than normotensive patients (5.9 +/- 1.3 ng/ml/hr versus 1.5 +/- 0.3 mg/ml/hr), selective renal vein renin measurements did not consistently demonstrate higher renin concentrations from the native kidneys. Removal of the original kidneys was beneficial even in some patients who had stenosis of the allograft artery demonstrated by arteriography.

Acute renal failure due to seminoma metastatic to the kidneys

A patient with seminoma presenting with bilateral symmetrical enlargement of the kidneys, massive proteinuria and acute renal failure is described. No factor other than infiltration due to seminoma was found to explain the renal failure. Renal function improved markedly along with renal size and architecture in response to radiotherapy. Renal dialysis is justified in metastatic seminoma to determine the effect of tumor therapy.

Factors influencing chloride reabsorption in the collecting duct segment of the rat

To study factors influencing Cl reabsorption in the collecting duct segment of the rat, excretion of Cl and of 36Cl injected into late distal tubule segments of superficial nephrons were examined by microinjection and free-flow micropuncture techniques. Selective dietary Cl restriction for 7-10 days decreased urinary 36Cl recovery for microinjection [74 +/- 5% (SE)] compared with normal rats (90 +/- 3%, P < 0.01). Infusion of 0.15 M NaHCO3 (10% body wt) in the Cl-restricted rat led to marked increases in urinary flow rates and sodium excretion but did not increase 36Cl recovery. In these NaHCO3-infused rats, recovery of 36Cl was unaffected by increasing Cl concentration in the injectate from 40 to 140 peq/nl, but increased to levels not different from control (89 +/- 3%) when amphotericin B was included in the injectate. Equivalent infusion of 0.15 M NaCl in the Cl-restricted rats also increased 36Cl recovery to control levels (89 +/- 3%). This response was not altered by administration of DOCA. Absolute chloride delivery to late distal tubule sites was not different in NaCl- and NaHCO3-expanded groups, and (TF/UF)Cl was less in the NaHCO3 group (0.27 +/- 0.03 vs. 0.37 +/- 0.02, P < 0.05); therefore, the chemical gradient for Cl did not favor Cl efflux. There was a significant correlation between urinary recovery of 36Cl and urinary Cl excretion in the NaCl- and NaHCO3-expanded animals. It is suggested that Cl restriction alters, by an as yet unknown mechanism that is independent of changes in Na balance, the intrinsic Cl-absorbing capacity of the collecting duct.

Does vesicoureteric reflux result in renal allograft failure?

Vesicoureteric reflux (VUR) into transplanted kidneys has been cited as an often disregarded but frequent complication of transplantation which is associated with a glomerular lesion that resembles membranoproliferative glomerulonephritis, marked proteinuria, and graft failure. To determine the prevalence of this complication in our transplant population, all of our 23 patients with marked proteinuria and 27 controls without proteinuria had voiding cystourethrograms performed approximately two years after transplantation. In our population, VUR was infrequent (8%). Moreover, in the three of the four cases detected renal function has not deteriorated and three of the four do not have marked proteinuria. We cannot confirm the suggestion that VUR is a frequent cause of late renal allograft failure.

Inhibition of renin secretion by HCl is related to chloride in both dog and rat

To determine if inhibition of renin release by HCl is related to acidosis or to Cl-, the effects of peripheral venous infusions of HCl and H2SO4 on plasma renin activity (PRA) were compared in the dog and the rat. In NaCl-deprived, pentobarbital-anesthetized dogs, either 0.15 M HCl (n = 10) or 0.075 M H2SO4 (n = 7) was infused for 60 min. In 5 of the 10 HCl-infused dogs (group A), urine Cl- excretion increased (P less than 0.01) during HCl infusion. In the remaining five dogs (group B), Cl- excretion did not increase. Cl- excretion also did not increase during H2SO4 infusion. Comparable acidosis was produced in all three groups. PRA decreased (P less than 0.01) in response to HCl in group A but did not change (P greater than 0.8) in group B HCl-infused dogs or in H2SO4-infused dogs. In NaCl-deprived, anesthetized rats, PRA was suppressed (P less than 0.05) by HCl (from 40.6 +/- 9.4 to 27.4 +/- 5.3 ng . ml-1 . h-1 (SE)) but not H2SO4 (from 37.1 +/- 4.2 to 37.0 +/- 6.3 ng . ml-1 . h-1), despite comparable acidosis. Cl- excretion increased only in HCl-infused rats. In conclusion, inhibition of PRA by acute infusion of HCl is specifically related to Cl-.

Focal and segmental glomerular sclerosis in reflux nephropathy

Reflux nephropathy was diagnosed in 23 patients (14 per cent of all the patients who received transplants) between 1973 and 1977, and nephrectomy was performed in all. Histology and immunofluorescence revealed a glomerular sclerosis associated with the idiopathic nephrotic syndrome. No focal and segmental glomerular sclerosis was seen in kidneys removed from patients with nonglomerular renal disease. Twenty-four hour urinary protein excretion in grams was 3.1 +/- 0.3 (mean +/- SEM) and was greater than that in our patients with end-stage nonglomerular renal disease. Thirty-one renal transplants were performed in these 23 patients; thereafter, maximum protein excretion was 1.4 g. Focal and segmental glomerular sclerosis was seen in only one (chronic rejection, protein excretion less than 0.5) of the 20 kidneys available for histologic study. Thus, focal and segmental glomerular sclerosis is extremely common in reflux nephropathy, accounts for "glomerular" proteinuria and may contribute importantly to progressive renal failure but, unlike that associated with the idiopathic nephrotic syndrome, rarely recurs after renal transplantation.

Effect of prednisone dose spacing on plasma lipids

We have previously reported a low prevalence of hyperlipidemia in renal transplant recipients who were treated with alternate-day corticosteroid. To determine whether alternate-day prednisone per se is associated with lower plasma lipids than is daily prednisone, we studied 14 renal transplant recipients with good allograft function (serum creatinine less than 2.5 mg/dl) who were normolipidemic on alternate-day prednisone. All patients were treated with 6 months of daily prednisone (10.9 +/- 0.4 mg, mean +/- S.E.) and then returned to 6 months of alternate-day prednisone (21.6 +/- 1.0 mg). Mean plasma triglyceride, cholesterol, and cholesterol fractions on either regimen were normal and not different. There were no differences in fasting or 2 hr postprandial glucose and insulin levels. Twelve patients gained weight on daily prednisone, and 11 patients lost weight on reversion to alternate-day prednisone. The changes in ideal body weight in both periods correlated (p less than 0.05) with changes in plasma triglycerides. These data suggest that a daily prednisone regimen per se as compared to an alternate-day regimen does not dispose normolipidemic patients to hyperlipidemia. The factors contributing to the low prevalence of hyperlipidemia in our renal transplant recipients remain obscure.

Renal vein thrombosis in IgA nephropathy

We report the first known case of renal vein thrombosis (RVT) in a patient with IgA nephropathy. We discuss the possible significance of this finding in support of the concept that RVT is a complication of glomerular disease.

Volume expansion-induced alterations in proximal tubule chloride gradient in the rat

To elucidate the mechanisms by which acute volume expansion (AVE) induces a decrease in proximal tubule transepithelial chloride gradient, male Sprague-Dawley rats were studied before and after AVE with Ringer lactate. In group 1, after AVE equivalent to 10% body wt, there were decreases in both tubule fluid to plasma inulin ratio ((TF/P)In) (from 2.28 +/- 0.10 to 1.57 +/- 0.05) and tubule fluid to ultrafiltrate chloride ratio ((TF/UF)Cl) (from 1.25 +/- 0.02 to 1.18 +/- 0.02). Group 2 was studied during carbonic anhydrase inhibition (CAI) produced by benzolamide before and during superimposed AVE (20% body wr). Both (TF/P)In (from 1.91 +/- 0.10 to 1.41 +/- 0.08) and (TF/UF)Cl (from 1.07 +/- 0.02 to 1.01 +/- 0.01) decreased. Group 3 was studied during maintained AVE (15% body wt) as a control for group 4, in which CAI was superimposed on maintained AVE. In group 3, (TF/P)In and (TF/UF)Cl did not change, but in group 4 CAI was associated with a decrease in (TF/P)In (from 1.55 +/- 0.05 to 1.21 +/- 0.05) and in (TF/UF)Cl (from 1.16 +/- 0.01 to 1.04 +/- 0.07). These data suggest that in the superficial proximal convoluted tubule of the rat, AVE-induced alterations in transepithelial chloride gradient are dependent on a mechanism(s) other than changes in carbonic anhydrase-mediated bicarbonate reabsorption.