Nephrotic proteinuria without hypoalbuminemia: clinical characteristics and response to angiotensin-converting enzyme inhibition

Although hypoalbuminemia is a fundamental characteristic of nephrotic syndrome (NS), there are many patients with massive proteinuria that do not develop hypoalbuminemia. We have studied the clinical and biochemical characteristics of 19 patients with persistent massive proteinuria (greater than 5 g/d) and normal serum albumin (group I) in comparison with 16 patients with similar proteinuria excretion, but persistent hypoalbuminemia (group II). Most of group I patients had diagnoses suggesting glomerular hyperfiltration (focal glomerulosclerosis [FGS] associated with vesicoureteral reflux [VUR], reduction of renal mass, proteinuria associated with obesity, sclerotic phase of idiopathic crescentic glomerulonephritis [GN] in contrast with those of group II, in which membranous GN was the most frequent diagnosis. We prospectively investigated differences in the antiproteinuric effect of captopril, an antiotensin-converting enzyme inhibitor (ACEI); after 6 months of treatment, proteinuria decreased clearly in group I (7.1 +/- 1.7 to 3.7 +/- 1.7 g/d; P less than 0.001), whereas no significant changes were observed in group II (8.1 +/- 2.4 to 8.8 +/- 4 g/d). Serum creatinine (Scr) remained stable during captopril treatment in group I, whereas three patients in group II showed a worsening of renal function.(ABSTRACT TRUNCATED AT 250 WORDS)

Tubular dysfunction in nephrotic syndrome: incidence and prognostic implications

Although some cases of tubular dysfunction (TD) associated with nephrotic syndrome have been described, the incidence and the characteristics of this complication remain unknown. We investigated the presence of TD (renal glycosuria, aminoaciduria, metabolic acidosis with normal anion gap, hypouricaemia, and throughout hypophosphataemia) in 36 patients with nephrotic syndrome. Ten patients (group 1) showed glycosuria at some time during the course of their illness, ranging from 2.5 to 11.2 g/24 h. In addition, seven of them had metabolic acidosis with normal anion gap, five aminoaciduria, and two hypouricaemia. Membranous glomerulonephritis was the most frequent aetiology in group 1 patients (7 of 10). Proteinuria and serum creatinine (SCr) were significantly higher in group 1 patients than in the 26 remaining patients without TD (group 2): 10.2 +/- 3.7 versus 6.7 +/- 2.9 g/24 h (P less than 0.01) and 3.2 +/- 1.9 versus 1.6 +/- 0.9 mg/dl (P less than 0.05) respectively. The appearance of TD coincided with a clear worsening of renal function in most of group 1 patients. In addition, at the end of follow-up, SCr had increased from 3.2 +/- 1.9 to 5.6 +/- 3.3 mg/dl (P less than 0.05) in this group. In contrast, SCr did not show significant changes in group 2 (1.6 +/- 0.9 versus 2.1 +/- 2.2 mg/dl). In conclusion, a significant proportion (27.7%) of patients with nephrotic syndrome present TD data at some moment of their course; the appearance of this complication appears to be a sign of poor prognosis.

Does calcium antagonist improve established early ciclosporin nephrotoxicity after renal transplantation?

We report a case of prolonged oliguric acute renal failure after renal transplantation under steroids and ciclosporin (Cs) immunosuppression. In the 2nd week when low fractional excretion of sodium values in the presence of oliguria (as expression of Cs nephrotoxicity) and high Cs blood levels were seen, a calcium antagonist drug was administered. Also, a Cs dose adjustment was made. Then, the diuresis and fractional excretion of sodium increased together with a progressive renal function. Although this evolution could be explained as a spontaneous resolution of postischemic renal failure, we speculated that in this case of established early Cs nephrotoxicity the effect of a calcium antagonist drug, such as nifedipine, could be beneficial.

Does an adequate control of blood pressure protect the kidney in essential hypertension?

We analyzed the clinical course of 120 patients who were diagnosed as having primary hypertension and subsequently given standard stepped-care therapy (diuretic, beta-blocker and vasodilator) for 9 years. At the end of the follow-up period, 21 patients (17.5%) had developed overt proteinuria. The initial study showed no difference in systolic blood pressure, age, sex, serum creatinine and its clearance, glucose, cholesterol and triglycerides between these patients and those who had not become proteinuric, but uric acid levels and diastolic blood pressure were higher (both P less than 0.01). An adequate control of blood pressure was obtained and maintained in all patients, who had similar therapeutic needs. During the follow-up period, uric acid levels remained significantly elevated (P less than 0.01) in the proteinuric patients, while changes in serum glucose, cholesterol and triglycerides were similar in all patients. These results indicate that long-term treatment of primary hypertensives does not fully protect kidney function and that initially elevated uric acid levels could be a predictor of a poor prognosis.

Long-term diuretic therapy and renal function in essential arterial hypertension

One of the main objectives of antihypertensive therapy is to preserve renal function from the deleterious effects of elevated blood pressure. Diuretics alone or in combination are effective for the treatment of arterial hypertension. Nevertheless, their use is accompanied by unwanted biochemical side effects, which have been attributed to their renal effects. During the last 10 years a group of 211 patients, diagnosed as having essential hypertension, were followed up. During the follow-up, they received a stepped-care therapeutic regimen consisting of nonpharmacologic measures (group 1), hydrochlorothiazide and amiloride (group 2), propranolol (group 3) and, if necessary, hydralazine (group 4). During the study, blood pressure remained within comparable, well-controlled levels in the 4 groups of patients. A progressive elevation of the levels of total serum cholesterol and glucose was observed in every group. The elevation attained statistical significance (p less than 0.01) after 4 years of therapy in those groups receiving the diuretic alone or in combination. Nevertheless, after 8 years of follow-up, the increment observed in these 2 parameters did not differ when patients in group 1 were compared with those in the remaining groups, indicating that thiazide diuretics could contribute to the earlier appearance of forthcoming events. Serum potassium levels were significantly lower (p less than 0.01) in groups 2 and 3 than in group 1. At the same time, we have observed the progressive appearance of clinically relevant proteinuria in 15.2% of patients, and the range of protein excretion ranged from 350 to 3,700 mg/24 hours. The appearance of proteinuria did not depend on the lack of control of blood pressure, nor on the different therapeutic requirements but was accompanied by a progressive decrease in creatinine clearance. The consequences of the renal effects of diuretics are of great importance during long-term therapy. The present results indicate that diuretics preempt the appearance of a forthcoming increase in serum glucose and cholesterol, and lessen the clinical relevance of these events.(ABSTRACT TRUNCATED AT 250 WORDS)

[The value of high dose steroid therapy in obstructive uropathy caused by a tumor]

The case of an 82-years old female patient with acute renal failure secondary to tumoral obstructive uropathy by neoplasic invasion of the trigone is described. The condition was treated with urinary deviation through percutaneous nephrostomy of the left kidney which achieved an improvement in the renal function. Later, the percutaneous nephrostomy was unintentionally moved not being possible to place a new one in none of the kidneys. The patient remained anuric for 24 hours, and therapy was then instaured with high doses of intravenous steroids (6 Metyl-Prednisolone 1.5 g I.V. in 24 hours), diuresis was recovered and renal function became normalized within a few days. The mechanism of action and therapeutic usefulness of high dosage steroids in tumoral obstructive pathology is discussed.

Effects of different dose levels and vaccination schedules on immune response to a recombinant DNA hepatitis B vaccine in haemodialysis patients

Hepatitis B is a frequent complication in haemodialysis patients because of their repeated exposure to blood products, and their impaired cellular and humoral response; trials with plasma-derived hepatitis B vaccine (PDV) show lower immune responses than those in healthy adults. Using a yeast-derived hepatitis B vaccine (YDV), the immunogenicity of two different dose levels (20 and 40 micrograms) and three vaccination schedules were compared in over 270 seronegative dialysis patients. Vaccination with 40 micrograms gave slightly better results than with the 20 micrograms dose. Seroconversion rates were higher with four dose, 40 micrograms vaccination schedules than a three dose schedule, and ranged from 80 to 86%. As the 40 micrograms, 0, 1, 2, 6 month schedule leads to a more rapid rise in antibody levels than the 40 micrograms, 0, 1, 2, 12 month schedule, it appears to be the most appropriate schedule in this patient group.

Senior-Loken syndrome (nephronophthisis and pigmentary retinopathy) associated to liver fibrosis: a family study

We present two sisters with nephronophthisis and pigmentary retinopathy (Senior-Loken syndrome) and associated liver fibrosis. Clinical and histological findings are discussed, as well as the importance of family studies. A comparative analysis with previous published cases is made; we found only three other references with this triad. Our report underlines the need to investigate liver disorders in all patients with nephronophthisis and the existence of liver fibrosis as an element of the hereditary 'nephronophthisis complex.'

Characterization of the renal effects of an intravenous calcium gluconate infusion in normotensive volunteers

The effects on renal function of an intravenous infusion of calcium gluconate at subpressor doses have been investigated in a group of seven normotensive male volunteers. In the absence of changes in blood pressure, the calcium gluconate induced a significant increase in renal plasma flow and the glomerular filtration rate (P less than 0.01) with a significant fall in the filtration fraction (P less than 0.01). Both diuresis and natriuresis increased significantly (P less than 0.01), plasma renin activity fell (P less than 0.01) and the urinary excretion of 6-keto prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E2 (PGE2) increased (P less than 0.01). These results indicate that calcium infusion at subpressor doses has renal vasodilating, diuretic and natriuretic properties that appear to be facilitated by an increase in the renal production of vasodilatory and natriuretic prostaglandins.

Diuretic and natriuretic properties of fenoldopam in chronic renal failure

The effect of intravenously administered fenoldopam on diuresis and natriuresis was investigated in a group of 10 patients with advanced chronic renal failure. After an initial basal period of 1 h, a fenoldopam infusion was started and maintained for 12 h at rates varying between 0.025 and 0.1 microgram/kg per min. During the study, blood pressure was measured every 10 min and urine volume, natriuresis and creatinine clearance were measured hourly. Fenoldopam induced a significant increase in urine volume, natriuresis and creatinine clearance (P less than 0.05-0.001) accompanied by a small but significant drop in blood pressure (P less than 0.05-0.01). These results show that for advanced chronic renal failure, fenoldopam has diuretic and natriuretic properties that could be of clinical relevance.

Immunogenicity of a yeast-derived hepatitis B vaccine in hemodialysis patients

In a multicenter study of hemodialysis patients in Spain, the immunogenicity of a yeast-derived recombinant deoxyribonucleic acid hepatitis B vaccine was evaluated. Two different vaccination schedules were examined: zero, one, two, six months and zero, one, two, 12 months. Two different dose levels (20 micrograms and 40 micrograms) were also compared. No serious adverse effects were reported by any of the vaccinees; the most frequently reported reaction was soreness at the injection site. This study also indicated that higher concentrations of antibodies are attained when more frequent doses of vaccine are administered. The yeast-derived vaccine produced an immune response similar to that of the plasma-derived vaccines.

Effects of angiotensin converting enzyme inhibitors on the progression of renal failure and proteinuria in humans

We studied the long-term effect of an angiotensin converting enzyme (ACE) inhibitor, captopril, on the progression of chronic renal failure and on the rate of urinary protein excretion. When compared with standard triple therapy, captopril slowed the progression of renal failure. Captopril was also able to reduce the proteinuria of non-diabetic glomerular origin. This reduction was not dependent on the presence or absence of arterial hypertension but was limited by the presence of low serum albumin levels, and only occurred in patients with proteinuria in excess of 3 g/24 h.

Hematuria due to hypercalciuria and hyperuricosuria in adult patients

We have prospectively studied 37 adult patients (15 males, 22 females; age 31 +/- 10.6 years) with previously undiagnosed isolated hematuria in which hypercalciuria or hyperuricosuria was found. Eighteen of them had had episodes of gross hematuria. Isolated hypercalciuria (4.4 to 10.4, X 5.6 +/- 1.9 mg/kg/24 hr) was found in nine patients (Group I), isolated hyperuricosuria (784 to 1500, X 1088 +/- 228 mg/24 hr) in 11 (Group II), and both hypercalciuria (4 to 8, X 4.9 +/- 1 mg/kg/24 hr) and hyperuricosuria (752 to 1476, X 1042 +/- 181 mg/24 hr) in 17 patients (Group III). Thiazide treatment for patients with hypercalciuria and allopurinol for those with hyperuricosuria were administered; calciuria and uricosuria became normal by the first month of therapy in every case. In 22 (59.4%) cases (Responder patients) hematuria resolved completely as soon as calciuria and uricosuria became normal. In the remaining 15 cases (Nonresponder patients) hematuria persisted despite the normal calcium and uric acid excretions. Several disorders that explained hematuria were diagnosed later in most of Nonresponder patients. Responder patients persisted without hematuria on the follow-up; only in three patients a transient relapse of hematuria was seen associated with a sudden increase of calciuria and uricosuria because of treatment withdrawal. There were no differences in age, male/female ratio nor in the basal values of calciuria and uricosuria between Responder and Nonresponder patients. A familial history of urolithiasis was found more frequently in Responder patients (64%) than in Nonresponders (20%) (P less than 0.05). We conclude that hypercalciuria and hyperuricosuria are definable and potentially reversible causes of hematuria in adult patients.

[Clinical characteristics of arterial hypertension in the elderly]

The clinical characteristics of systolic and diastolic hypertension in 75 and of systolic hypertension in 50 elderly patients have been studied and the results have been compared to those obtained in 23 normotense elderly controls and 500 young patients with essential hypertension. A greater incidence in cardiovascular and neurologic morbility was observed in the hypertense elderly, existing also a greater incidence of electrocardiographic abnormalities and impairment in renal function. The changes in blood pressure with postural changes and isometric and physical exercise were evaluated in a subgroup of these patients, finding that the elderly with hypertension, specially those with systolic hypertension, showed orthostatic hypotension, and an increase in blood pressure with exercise, reaching levels that could potentially cause the clinical complications.

[Treatment of arterial hypertension in the aged]

The response to different therapeutic schedules in arterial hypertension in the elderly is studied and compared with response to treatment in younger patients. Blood pressure in the elderly was best controlled with non pharmacologic measures and low doses of diuretics; there were no differences between both groups with respect to complications and side effects. The response to angiotensin-converting enzyme inhibitors is also evaluated, presenting good results on blood pressure control without side effects in the elderly, although efficaciousness was higher in younger patients. The possible therapeutic schedules in arterial hypertension in the aged are discussed.