Follow-up of renal function in treated and untreated older patients with isolated systolic hypertension. Systolic Hypertension in Europe (Syst-Eur) Trial Investigators

BACKGROUND

In the outcome trials that provided information on renal function in older hypertensive patients, diuretics and beta-blockers were mostly used as first-line drugs. The long-term renal effects of calcium-channel blockers remain unclear.

OBJECTIVE

To compare the changes in renal function in 2,258 treated and 2,148 untreated patients with isolated systolic hypertension, of whom 455 had diabetes mellitus and 390 had proteinuria.

METHODS

We performed a post-hoc analysis of the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) Trial. Active treatment was initiated with nitrendipine (10-40 mg/day) with the possible addition of enalapril (5-20 mg/day), hydrochlorothiazide (12.5-25 mg/day), or both, titrated or combined to reduce the sitting systolic blood pressure by at least 20 mmHg, to less than 150 mmHg. The main outcome measures were serum creatinine concentration and creatinine clearance calculated by the formula of Cockroft and Gault.

RESULTS

Serum creatinine concentration at the time when participants were randomly allocated to study groups was less than 176.8 micromol/l (2.0 mg/dl), averaging 88 micromol/l. At the time of the last serum creatinine measurement, the blood pressure difference (P< 0.001) between the two groups was 11.6/4.1 mmHg. In the intention-to-treat analysis (11,427 patient-years), serum creatinine and the calculated creatinine clearance were not influenced by active treatment. However, in the patients assigned randomly to receive active treatment, the incidence of mild renal dysfunction (serum creatinine at least 176.8 mmol/l) decreased by 64% (P= 0.04) and that of proteinuria by 33% (P= 0.03). Active treatment reduced the risk of proteinuria more in diabetic than in non-diabetic patients: by 71%, compared with 20% (P= 0.04). In non-proteinuric patients, active treatment did not influence serum creatinine, whereas in patients with proteinuria at entry to the study, serum creatinine decreased on active treatment (P< 0.001). Furthermore, in on-randomized treatment comparison stratified for risk at baseline, serum creatinine concentration did not change (P= 0.98) in patients continuing to receive monotherapy with nitrendipine, whereas it increased by 6.73 mmol/l (P < 0.001) in patients who received hydrochlorothiazide alone or in combination with other study medication (P < 0.001 for difference in trends).

CONCLUSIONS

In older patients with isolated systolic hypertension, antihypertensive treatment starting with the dihydropyridine calcium-channel blocker, nitrendipine, did not decrease blood pressure at the expense of renal function and prevented the development of proteinuria, especially in diabetic patients.

What is the optimal blood pressure target in renal patients?

Chronic renal failure and arterial hypertension run in parallel. New goal BP levels have been established as 130/85 mm Hg and 125/75 mm Hg, depending on whether the level of proteinuria is less than or greater than 1 g/d. New and lower threshold BP (> 130/85 mm Hg) to initiate pharmacologic therapy is required in the presence of renal failure, to facilitate the strict BP control that is required. Hence, it is necessary to consider that both renal and cardiovascular protection are obtained with strict BP control, which otherwise seems to require blockade of angiotensin II effects when proteinuria above 1 g/d is present.

[Diagnostic and clinical course features of lupus membranous glomerulonephritis]

BACKGROUND

Lupus membranous glomerulonephritis (LMG) is sometimes difficult to distinguish from idiopathic membranous glomerulonephritis (IMG) and little is known about its natural history.

METHODS

We have performed a retrospective study of 16 patients with LMG, types Va ("pure" LMG) (8 patients) and Vb (mesangial proliferation) (8 patients). Analytical and clinical characteristics were analyzed in each case at the onset of the disease and during follow-up.

RESULTS

At the time of diagnosis, 7 patients (43%) did not present any extrarenal manifestations of systemic lupus erythematosus (SLE). Nephrotic syndrome was the most common clinical presentation (81%). 14 patients (87%) showed positive antinuclear antibodies (ANA), but at low titres (< 1/300); anti-DNA antibodies were positive only in 3 cases (18%) and hypocomplementemia was observed in 2 (12%). The most relevant histological findings were the presence of Clq deposits (83%) and subendothelial and mesangial deposits. Treatment consisted of corticosteroids, adding immunosuppression when no response was obtained in 2-3 months. In recent years, an angiotensin-converting enzyme inhibitor (ACEI) was added before immunosuppression. At the end of the study, 6 patients (42%) developed chronic renal insufficiency and 8 (58%) renainea with normal renal function. Actuarial renal survival was 100% at 5 years and 75% at 10 years. The evolution towards a non-nephrotic range proteinuria throughout the follow-up was the only parameter significantly associated with a good prognosis.

CONCLUSIONS

LMG can present without extra-renal symptoms of SLE and even with very poor expression of its serological markers. Almost half of the patients (42%) developed chronic renal insufficiency. The evolution towards a non-nephrotic range proteinuria correlated with the maintenance of a normal renal function.

Ischemic nephropathy: clinical characteristics and treatment

Ischemic nephropathy is a long-term cause of hypertension and renal failure. Although its real incidence is unknown, ischemic nephropathy is growing because of the increased mean age of the population and the greater prevalence of hypertensive and diabetic populations. This review describes the clinical profile of afflicted patients. Atherosclerosis in different vascular beds is common in these patients. The evolution of ischemic nephropathy is generally progressive, although some patients present with acute renal failure, either secondary to the administration of angiotensin-converting enzyme inhibitors or caused by thrombosis of the renal arteries. Revascularizing surgery may stabilize or improve renal function, even in patients with nonfunctioning kidneys. The results obtained with intraluminal angioplasty are worse, with a high percentage of restenosis. Placement of an endoprothesis is recommended when the lesions affect the ostium or proximal third of the artery. This complex disease typically affects multiple organs, thus making individual assessment essential.

Influence of obesity on the appearance of proteinuria and renal insufficiency after unilateral nephrectomy

BACKGROUND

Some patients develop proteinuria and progressive renal failure after unilateral nephrectomy, although the majority of patients maintain normal renal function. Reasons to explain this different evolution are not known.

METHODS

A cross-sectional study was performed in 73 patients who had undergone unilateral nephrectomy 13.6 +/- 8.6 years before. Patients with morphologic abnormalities in the remaining kidney, systemic disorders, or abnormal renal function at the time of nephrectomy were excluded. All of the 73 included patients showed normal renal function and negative proteinuria at nephrectomy. The patient's medical records were reviewed, and clinical and analytical data throughout follow-up were obtained.

RESULTS

Fifty-three out of the 73 patients (group I) showed a normal renal function and negative proteinuria at the cross-sectional study. The remaining 20 patients (group II) showed proteinuria (3.4 +/- 3.1 g/day). The time elapsed between nephrectomy and proteinuria appearance was 10.1 +/- 6.1 years. Thirteen patients of group II had developed renal insufficiency (serum creatinine at the cross-sectional study of 3.9 + 3.2 mg/dL) in addition to proteinuria. The time elapsed between proteinuria appearance and the onset of renal insufficiency was 4.1 +/- 4.3 years. Renal insufficiency showed a slowly progressive course in most of these patients. There were no significant differences between group I and group II patients in age, gender, renal function, or blood pressure at the time of nephrectomy. In contrast, group II patients showed a body mass index (BMI) that was significantly higher than group I at nephrectomy (31.6 +/- 5.6 vs. 24.3 +/- 3.7 kg/m(2), P < 0.001), at cross-sectional study (33.3 +/- 6.6 vs. 25.1 +/- 3.5 kg/m(2), P < 0.001), and throughout follow-up. Among the 14 obese (BMI > 30 kg/m(2)) patients at the time of nephrectomy, 13 (92%) developed proteinuria/renal insufficiency. In contrast, among the 59 patients with BMI < 30 kg/m(2), only 7 (12%) developed these complications (P < 0.001). Kaplan-Meier estimated probability of negative proteinuria and normal renal function 10 years after nephrectomy was 40 and 70%, respectively, in obese patients at nephrectomy. At 20 years after nephrectomy, these percentages were 8 and 35%, respectively. In contrast, in nonobese patients, the probability of negative proteinuria and normal renal function was 93 and 98%, respectively, at 10 years (P < 0.001) and 77 and 91%, respectively, at 20 years (P < 0.001). Multiple logistic regression analysis showed that the risk of developing renal disease was only statistically correlated with BMI at the time of unilateral nephrectomy (odds ratio 1.34, 1.03 to 1.76 CI).

CONCLUSIONS

Obese patients are at risk for developing proteinuria and chronic renal failure after unilateral nephrectomy. Regular and long-term follow-up are recommended in these patients.

Response to antihypertensive therapy in older patients with sustained and nonsustained systolic hypertension. Systolic Hypertension in Europe (Syst-Eur) Trial Investigators

BACKGROUND

The goal of the present study was to assess the effect of antihypertensive therapy on clinic (CBP) and ambulatory (ABP) blood pressures, on ECG voltages, and on the incidence of stroke and cardiovascular events in older patients with sustained and nonsustained systolic hypertension.

METHODS AND RESULTS

Patients who were >/=60 years old, with systolic CBP of 160 to 219 mm Hg and diastolic CBP of <95 mm Hg, were randomized into the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) Trial. Treatment consisted of nitrendipine, with the possible addition of enalapril, hydrochlorothiazide, or both. Patients enrolled in the Ambulatory Blood Pressure Monitoring Side Project were classified according to daytime systolic ABP into 1 of 3 subgroups: nonsustained hypertension (<140 mm Hg), mild sustained hypertension (140 to 159 mm Hg), and moderate sustained hypertension (>/=160 mm Hg). At baseline, patients with nonsustained hypertension had smaller ECG voltages (P<0.001) and, during follow-up, a lower incidence of stroke (P<0.05) and of cardiovascular complications (P=0.01) than other groups. Active treatment reduced ABP and CBP in patients with sustained hypertension but only CBP in patients with nonsustained hypertension (P<0.001). The influence of active treatment on ECG voltages (P<0.05) and on the incidence of stroke (P<0.05) and cardiovascular events (P=0.06) was more favorable than that of placebo only in patients with moderate sustained hypertension.

CONCLUSIONS

Patients with sustained hypertension had higher ECG voltages and rates of cardiovascular complications than did patients with nonsustained hypertension. The favorable effects of active treatment on these outcomes were only statistically significant in patients with moderate sustained hypertension.

Cholesterol levels in untreated Spanish hypertensive patients. The Compas Study Group, Spanish Hypertension Society

In daily practice, arterial hypertension (AHT) and hypercholesterolaemia are frequently associated with the existence of multiple common etiopathogenic interrelationships. This situation leads to an exponential increase in cardiovascular risk for these patients, so it is essential to know the prevalence and therapeutic management of hypercholesterolaemia in the hypertensive patient. This national study analyses the distribution of total cholesterol levels and low-density lipoprotein cholesterol as well as hypercholesterolaemia prevalence and its therapeutic management in the uncontrolled hypertensive Spanish population. We observed mean total cholesterol levels of 227+/-41 mg/dl with a high prevalence of hypercholesterolaemia (34.2%) among hypertensive patients, and the percentage of those patients with "desirable" total cholesterol levels (<200 mg/dl) was <25%. The treated hypertensive patients presented both significantly higher mean cholesterol levels and greater hypercholesterolaemia prevalence than the untreated hypertensive patients. It appears that total cholesterol levels are scarcely related to the presence or non-presence of obesity, diabetes or smoking. Regarding treatment, only 14.6% of the hypercholesterolaemic hypertensive patients received hypolipaemic treatment with statins. These results support the need to introduce measures for better diagnostic and therapeutic management of hypercholesterolaemic hypertensive patients that will lead to a much higher reduction in cardiovascular risk for these patients.

Calcium Antagonists and Renal Protection from Cyclosporine Nephrotoxicity: Long-term Trial in Renal Transplantation Patients

Cyclosporine (CsA) treatment in solid organ transplantation has represented one of the greatest advances in the past 20 years, reducing acute rejection and increasing long-term survival. However, CsA has an important side effect, producing renal vasoconstriction and systemic hypertension. The main histological findings in the kidney are vascular lesions in the endothelium and smooth muscle cells. On proximal tubule cells, severe atrophy, vacuolization and thickening of the basal membrane can be found. The main mechanisms of vasoconstriction are secondary to endothelium disorders, increasing vasoconstrictor substances like endothelin, thromboxane, free radicals, etc., and reducing vasodilator substances like nitric oxide and prostaglandins. CsA acute nephrotoxicity produces haemodynamic changes with minor histological lesions, which will disappear when the medication is discontinued. Long-term CsA nephrotoxicity has been widely discussed in the literature. For some authors, a limited number of patients can develop end-state renal failure but others did not suffer these complications. Nevertheless, it seems clear that high doses of CsA can produce renal lesion and renal insufficiency, being difficult to evaluate in renal transplant patients because of the frequent association with chronic rejection lesions. Several types of drugs have been used to treat CsA nephrotoxicity in renal transplant patients but calcium antagonists and angiotensin converting enzyme-inhibitors are the most frequently used, especially the former due to their effect on the afferent arteriole vasodilatation, their natriuretic properties and their reducing intracellular calcium. The greatest experience has been with nifedipine, but other drugs like verapamil, diltiazem, amlodipine, felodipine, isradipine, etc., have also been used. Lacidipine, a 1,4-dihydropiridine, has demonstrated a beneficial effect during the short term after renal transplantation, and a multicentre, multinational, double-bind, placebo-controlled clinical trial for the long term currently ongoing.

Renal surrogates in essential hypertension

The kidney can be considered both as culprit and victim in the hypertensive process. Renal functional derangement contributes to the development of arterial hypertension and the development of secondary vascular damage both at the glomerular and arteriolar level accounts for the development of progressive nephrosclerosis. The most common alteration of renal function observed in humans since the early stages of essential hypertension is the presence of renal vasoconstriction. This can be accompanied by the appearance of hyperuricemia, increased urinary excretion of enzymes such as N-acetyl-beta- glucosaminidase and of proteins like albumin and beta2-microglobulin. Later on, a progressive fall in glomerular filtration rate accompanied or not by proteinuria can be observed if high blood pressure persists.

Microalbuminuria in essential hypertension

Microalbuminuria is frequently seen in patients with established essential hypertension, and is a predictor of a higher risk for cardiovascular and probably renal dysfunction. The presence of microalbuminuria has been shown to correlate with the other cardiovascular risk factors commonly seen in hypertensive patients. This fact indicates that the detection of an increased urinary albumin excretion could probably be the best index of an increased global cardiovascular risk in a given patient. Blood pressure control is accompanied by a fall in the content of albumin in urine. Agents with the capacity to block the renin-angiotensin system have shown a capacity to decrease urinary albumin excretion, which is independent of their ability to lower blood pressure. Whether or not a decrease in urinary albumin excretion is accompanied by an improved renal and cardiovascular prognosis in hypertensive patients remains to be elucidated.

Association of thin basement membrane nephropathy with hypercalciuria, hyperuricosuria and nephrolithiasis

BACKGROUND

Familial persistent microhematuria with normal renal function is the most common presentation of thin basement membrane nephropathy (TBMN). Gross hematuria episodes and loin pain attacks are other manifestations of the disease. On the other hand, it has been shown that hypercalciuria (HC) and hyperuricosuria (HU) can produce both gross or microscopic non-glomerular hematuria, in addition to their role in renal stone formation.

METHODS

We studied the prevalence of HC, HU and nephrolithiasis in a group of 27 biopsy-proven TBMN as well as in 19 non-biopsied first-degree relatives with persistent microhematuria and 25 first-degree relatives without microhematuria. A group of 27 patients with IgA nephropathy (IgAN) and persistent microhematuria, and another group of 20 healthy subjects without known renal diseases were selected as control groups.

RESULTS

Ten (37%) patients with TBMN and 8 (42%) relatives with microhematuria showed HC and/or HU at presentation; relatives without microhematuria, IgAN patients and normal controls showed a significantly lower prevalence of HC and HU. The prevalence of previous nephrolithiasis among TBMN patients (25%) was significantly higher than in IgAN patients (3%; P < 0.05). Family history of nephrolithiasis was recorded in 14 (51%) of the 27 TBMN families, in contrast with 2 of 27 (7%) with IgAN and 1 of 20 (5%) in normal controls (P < 0.05). The prevalence of nephrolithiasis, gross hematuria bouts and loin pain episodes among TBMN patients and microhematuric relatives showing HC and/or HU at presentation (44%, 44% and 27%, respectively) were significantly higher than those of TBMN patients and microhematuric relatives with normal calcium and uric acid urinary excretions (10%, 7% and 3%, respectively; P < 0.05). At the end of follow-up (8.8+/-4.1 years in TBMN patients and 9.1+/-4.2 years in relatives with microhematuria), all the cases maintained normal renal function.

CONCLUSIONS

We found a high prevalence of HC, HU, and nephrolithiasis among TBMN patients and relatives with microhematuria. Our study also shows a significant relationship between the presence of HC and/or HU and the prevalence of nephrolithiasis, gross hematuria bouts and loin pain episodes.

Fibrosing cholestatic hepatitis in hepatitis C virus-infected renal transplant recipients

Severe hepatitis C virus (HCV)-related fibrosing cholestatic hepatitis leading to early liver failure has been reported only exceptionally. Of 259 HCV-infected renal transplant (RT) patients in one hospital unit, four (1.5%) are described, representing the first series of this particular post-RT disease. Patient mean age was 55.7 yr. Three were men. All had pretransplant, hepatitis B surface antigen-negative and were anti-HCV antibodies positive. Three of them showed pretransplant mild liver enzyme abnormalities, and all received kidneys from HCV-negative donors. All were on steroids, cyclosporine, and azathioprine (AZA). The clinical pattern appeared early after RT (mean, 11.5 mo). In three patients, hyperbilirubinemia (6.5 to 20 mg/dl) and high alkaline phosphatase levels (428 to 859 IU/L) were observed. Also, in all subjects, high gamma glutamyl transpeptidase levels (639 to 4270 IU/L), mild aspartate aminotransferase and alanine aminotransferase abnormalities, and serum HCV RNA were observed. Liver biopsy revealed diffuse fibrosis, leukocyte infiltrates, and different degrees of cholestasis, with typical signs of HCV hepatitis in only one patient. Two patients developed subfulminant liver failure and died 2 and 3 mo after biopsy, respectively. One patient also suffered hepatic failure, receiving a liver transplant. The fourth is alive on dialysis awaiting a combined kidney and liver transplant. It is concluded that fibrosing cholestatic hepatitis is a new, early, and severe complication after RT in HCV(+) patients, which appears in patients with ongoing HCV infection under AZA therapy, despite a nonaggressive immunosuppressive protocol. Both HCV and AZA could play a concurrent role in the pathogenesis of this severe complication after RT.

Lipoprotein abnormalities in long-term stable liver and renal transplanted patients. A comparative study

Hyperlipidemia is a common feature after organ transplantation. Most studies have evaluated the lipid profile in recipients of a particular graft, usually renal. In the present work, we studied the lipid profiles of 30 long-term stable liver transplant patients (LTP) and compared their pattern with 40 long-term stable renal transplant patients (RTP) matched for gender, age, and time from transplantation. There were no significant differences between both groups in body mass index, serum glucose, serum creatinine, or urinary protein excretion. In contrast, RTP had higher pre-transplant total cholesterol and triglycerides, received higher doses of steroids (both average and cumulative) and had higher cycosplorine blood levels. After a mean time of 60 months after transplantation, RTP exhibited higher levels of total serum cholesterol (226 +/- 26 vs. 180 +/- 39 mg/dl; p = 0.000 002) and low-density lipoprotein (LDL) cholesterol (152 +/- 22 vs. 112 +/- 37 mg/dl; p = 0.00001). In contrast, there were no differences between RTP and LTP in high density lipoprotein (HDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, total triglycerides, VLDL triglycerides, or lipoprotein (a) [Lp(a)]. By univariate analysis in the whole group, renal graft, prednisone daily dose, cyclosporine blood levels, pre-transplant cholesterol, and triglycerides were associated with increased post-transplant cholesterol levels. By multivariate analysis, prednisone daily dose was the only independent variable predicting increased post-transplant serum cholesterol levels. The present data show that hypercholesterolemia is more frequent among RTP than among LTP. In addition, our data suggest that corticosteroid therapy, rather than the transplanted organ, may be the major contributor to this difference.

Hepatitis C virus and renal transplantation

During the past 12 months additional evidence has emerged from several studies, indicating that hepatitis C virus infection is the most important liver disease after renal transplantation. A new, severe and rare entity called fibrosing cholestatic hepatitis can lead to early liver failure, although the most important complications appeared in the long-run. Encouraging results with ribavirin have been described. Although glomerular lesions and more severe infections can appear in hepatitis C virus patients, graft and patient survival rates in most series are similar to those in hepatitis-C-negative patients. Survival is also better among hepatitis-C-positive patients after renal transplantation than in hepatitis-C-positive patients on dialysis on the waiting list for transplantation. Finally, the use of kidneys from hepatitis-C-positive donors is suggested for transplant into hepatitis C RNA positive patients matching the hepatitis C genotype.

Blood pressure control, proteinuria and renal outcome in chronic renal failure

The presence of proteinuria has been shown to be an excellent predictor for a worse outcome of renal function. Both proteinuria and arterial hypertension often coexist in the same patient, and therapy must be directed at decreasing protein excretion in the urine as well as lowering the blood pressure. Any antihypertensive agent has the capacity to lower proteinuria simply by lowering blood pressure. Furthermore, the antiproteinuric capacity of angiotensin-converting enzyme inhibitors can be equalized by other agents or their combination, provided that the fall in blood pressure is great enough. For this reason studies are needed in which the strict control of arterial hypertension combined with a decrease in proteinuria are considered.

Prognostic value of ambulatory blood pressure monitoring in refractory hypertension: a prospective study

The objective of this study was to establish whether ambulatory blood pressure offers a better estimate of cardiovascular risk than does its clinical blood pressure counterpart in refractory hypertension. This prospective study assessed the incidence of cardiovascular events over time during an average follow-up of 49 months (range, 6 to 96). Patients were referred to specialized hypertension clinics (86 essential hypertension patients who had diastolic blood pressure > 100 mm Hg during antihypertensive treatment that included three or more antihypertensive drugs, one being a diuretic). Twenty-four-hour ambulatory blood pressure monitoring (ABPM) was performed at the time of entrance. End-organ damage was monitored yearly, and the incidence of cardiovascular events was recorded. Patients were divided into tertiles of average diastolic blood pressure during activity according to the ABPM, with the lowest tertile <88 mm Hg (LT, n=29), the middle tertile 88 to 97 mm Hg (MT, n=29), and the highest tertile >97 mm Hg (HT, n=28). While significant differences in systolic and diastolic ambulatory blood pressures were observed among groups, no differences were observed at either the beginning or at the time of the last evaluation for office blood pressure. During the last evaluation, a progression in the end-organ damage score was observed for the HT group but not for the two other groups. Twenty-one of the patients had a new cardiovascular event; the incidence of events was significantly lower for the LT group (2.2 per 100 patient-years) than it was for the MT group (9.5 per 100 patient-years) or for the HT group (13.6 per 100 patient-years). The probability of event-free survival was also significantly different when comparing the LT group with the other two groups (LT versus MT log-rank, P<.04; LT versus HT log-rank, P<.006). The HT group was an independent risk factor for the incidence of cardiovascular events (relative risk, 6.20; 95% confidence interval, 1.38 to 28.1, P<.02). Higher values of ambulatory blood pressure result in a worse prognosis in patients with refractory hypertension, supporting the recommendation that ABPM is useful in stratifying the cardiovascular risk in patients with refractory hypertension.

The natriuretic effect of nifedipine gastrointestinal therapeutic system remains despite the presence of mild-to-moderate renal failure

BACKGROUND

Calcium channel blockers facilitate the renal excretion of sodium and this effect is maintained during chronic administration of these drugs. However, it is unknown whether this natriuretic effect remains despite the presence of a decreased renal function.

OBJECTIVE

To compare the natriuretic capacity of nifedipine gastrointestinal therapeutic system (GITS) and lisinopril in patients with mild-to-moderate chronic renal failure.

METHODS

An open-label, randomized, comparative study was conducted to compare the natriuretic capacity of nifedipine GITS and lisinopril in the presence of mild-to-moderate renal failure (creatinine clearance 30-80 ml/min). After a wash-out period of 4 weeks an intravenous saline infusion (30 ml/kg of body weight of isotonic saline in 4 h) was performed and repeated after 4 weeks of active therapy. Two sex- and age-matched groups of hypertensive patients (n = 25) were included in the study. Renal failure was diagnosed as secondary to nephrosclerosis in all the patients.

RESULTS

A significant increase in the renal capacity to excrete the sodium load was observed in patients receiving nifedipine GITS (n = 11) but not in those taking lisinopril (n = 13). Both drugs controlled blood pressure to a similar extent. No changes were observed in body weight, glomerular filtration rate and renal plasma flow (measured as inulin and paraaminohippurate clearances). A significant drop was observed in urinary albumin excretion after lisinopril, but not after nifedipine. Heart rate was higher in nifedipine group.

CONCLUSION

The natriuretic capacity of nifedipine GITS remains despite the presence of mild-to-moderate chronic renal failure. Such an effect takes place in the absence of changes in renal hemodynamics, suggesting that it is caused by a direct tubular effect.

Antiproteinuric effect of angiotensin-converting enzyme inhibition and C5b-9 urinary excretion in membranous glomerulonephritis

BACKGROUND

Angiotensin-converting enzyme (ACE) inhibitors have an antiproteinuric effect in membranous glomerulonephritis (MGN). However, no studies have investigated whether this antiproteinuric effect is influenced by urinary C5b-9 excretion, a marker of immunological activity in this disease.

METHODS

Eleven patients with biopsy-proven MGN were treated with captopril for 8 weeks. The evolution of several clinical and biochemical parameters, including 24-h urinary protein excretion was evaluated every 4 weeks. Urinary C5b-9 excretion was measured at the onset and at the end of captopril treatment.

RESULTS

Patients with MGN had significantly higher C5b-9 excretions than a group of 14 healthy controls (89 +/- 23 vs 3.7 +/- 1.4 ng/mg UCr; P < 0.001). A significant correlation was found between urinary C5b-9 and the magnitude of proteinuria, both at the onset and at the end of treatment. After 8 weeks of captopril treatment, proteinuria had decreased from 8 +/- 1.8 to 5.2 +/- 1.3 g/day (P < 0.05). Four weeks after captopril discontinuation, proteinuria rose to 7.3 +/- 1.7 g/day (P < 0.05). A marked variability in the antiproteinuric response was observed, ranging from 0 to 85% with respect to baseline values. No correlation between decrease in proteinuria and baseline urinary C5b-9 levels was observed. Several patients with elevated urinary C5b-9 levels had captopril-induced decrease in proteinuria.

CONCLUSIONS

ACE inhibition induces an antiproteinuric effect in patients with MGN. The urinary C5b-9 excretion does not predict the magnitude of this response.

Glomerular diseases in patients with hepatitis C virus infection after renal transplantation

Currently, it is well known that hepatitis c virus (HCV) represents the major cause of chronic liver disease in renal transplant patients. On the other hand, HCV has been described in association with different types of glomerular diseases, usually type I membranoproliferative glomerulonephritis (MGPN) and less frequently membranous glomerulonephritis (MGN). After renal transplantation two glomerular entities have described in HCV positive patients: MPGN, associated or not with cryoglobulinemia, hypocomplememtemia and rheumatoid factor and another lesion was MGN. All patients had chronic HCV infection and with detectable HCV RNA in the serum, developed proteinuria, nephrotic syndrome and microhematuria. Characteristically MGN occurs without cryoglobulinemia, hypocomplememtemia and rheumatoid factor. The clinical pictures and outcomes of these pathological pictures seem to be similar to those of the novo MPGN or MGN in renal transplant patients. These entities seem to be more frequent in HCV-positive than in HCV-negative patients. Also, a possible relationship between HCV infection and transplant glomerulopathy has been described. Therefore, in renal transplant patients with proteinuria, serology for HCV infection, HCV RNA and immunological tests should be performed as part of the differential diagnosis.