Hemofiltration in Myoglobinuric Acute Renal Failure

The frequency of myoglobinuric renal failure is estimated between 8 and 20%. Despite early onset of therapy often the use of renal substitution by hemodialysis or hemofiltration is required. This study of the clinical course of nine patients with myoglobinuric acute renal failure reveals continuous arterio-venous hemofiltration (CAVH) to have an effective clearance for myoglobin. Thus, the time until recovery of renal function as well as the frequency of secondary complications in rhabdomyolysis induced acute renal failure can be distinctly reduced.

Area under the viraemia curve versus absolute viral load: utility for predicting symptomatic cytomegalovirus infections in kidney transplant patients

A novel approach to predicting symptomatic cytomegalovirus (CMV) infections combines the level and the duration of viraemia in a single parameter. Sixty-four kidney transplant recipients were monitored by quantitative shell vial culture, pp65 antigenaemia, and polymerase chain reaction (PCR) of leucocytes. The area under the curve (AUC) of each parameter was determined from the onset of viraemia to the beginning of antiviral treatment. The AUC values were significantly higher in symptomatic than in asymptomatic patients. For antigenaemia and PCR, optimal AUC thresholds for predicting symptomatic CMV infections were determined. They were superior to standard cutoff levels of absolute viral load in sensitivity, specificity, and positive and negative predictive value. In 8 of the 23 patients who became symptomatic, impending clinical features were indicated earlier by the AUC thresholds than by standard viral load. In conclusion, the concept of the AUC should facilitate identification of patients at risk of symptomatic CMV infection.

Do serum C-reactive protein measurements help to discriminate episodes of renal dysfunction in patients after renal transplantation?

INTRODUCTION

This study investigated whether serial daily measurements of serum C-reactive protein (sCRP) could help differentiate episodes of transplant dysfunction due to rejection, infection, cyclosporine A (CsA) nephrotoxicity, or acute tubular necrosis (ATN) in renal-allograft recipients.

MATERIALS AND METHODS

Morning serum was obtained daily from 134 patients during the first 30 days after renal transplantation. All episodes of graft dysfunction were recorded and differentiated with transplant biopsies. CRP concentrations were correlated with post-operative graft function and the various causes of graft dysfunction.

RESULTS

All patients showed an increase in sCRP in response to surgery, with a maximum on day 2 after transplantation. The sCRP concentration was significantly higher in patients with delayed graft function (mean 61.50 microg/ml) than in patients with primary graft function (mean 38.01 microg/ml) (p=0.001). Bacterial infections other than asymptomatic bacteriuria (mean sCRP 33.98 microg/ml), interstitial graft rejection (mean sCRP 16.43 microg/ml), and ATN (mean sCRP 30.50 microg/ml) were accompanied by significant increases in sCRP compared with uneventful courses. sCRP was unchanged in the presence of viral infections or CsA toxicity.

CONCLUSION

Serial sCRP measurements help to identify renal-transplant dysfunction of different origins. However, rejection, infection and ATN show similar patterns of sCRP increase. Thus, sCRP is unable to discriminate the causes of renal-graft dysfunction. Biopsy remains the gold standard for the differential diagnosis of renal-allograft dysfunction.

False-positive results of plasma PCR for cytomegalovirus DNA due to delayed sample preparation

Positive results by cytomegalovirus (CMV) PCR of plasma are considered predictive of active CMV infection in kidney allograft recipients. To assess whether contamination with leukocyte-derived CMV DNA can distort the results, aliquots of whole-blood samples from 60 CMV immunoglobulin G-positive patients with leukocyte CMV DNAemia were stored for up to 24 h at room temperature (RT) and at 4 degrees C before plasma preparation. Native and ultrafiltered plasma samples were tested by CMV and beta-globin PCRs. Among 30 latently infected patients (negative for CMV pp65 antigens), low baseline rates (10%) and levels (median number of copies, 10 [per 10 microl]) of CMV plasma DNAemia in native plasma samples increased significantly over time (after 4 h at RT, 37% [P < 0.001]; median number of copies, 45 [P < 0.001]). Similar effects were found during storage at 4 degrees C. Ultrafiltration reduced the levels of CMV plasma DNAemia, but by 6 h of storage the levels were significantly elevated as well. CMV and beta-globin DNA kinetics in plasma were parallel. In contrast, 30 actively infected patients (pp65 positive) had high baseline rates (87% in native samples) and levels (median number of copies, 75) of CMV plasma DNAemia. No significant effects of storage or ultrafiltration and no concordance with beta-globin DNA kinetics were seen. In conclusion, delayed preparation of plasma samples bears a significant risk of false-positive CMV PCR results, probably due to leukocyte lysis. This has important implications in the clinical setting and for PCR standardization.

Cytomegalovirus cultured from different major leukocyte subpopulations: association with clinical features in CMV immunoglobulin G-positive renal allograft recipients

Cytomegalovirus (CMV) cultured from peripheral blood mononuclear cells (PBMCs) was shown to be associated more closely with clinical manifestations than infectious CMV in polymorphonuclear leukocytes (PMNLs) of renal allograft recipients with secondary CMV infection. Shell vial culture was carried out with ficoll-purified PBMCs and PMNLs of 71 CMV IgG-positive patients after kidney transplantation. Thirty-six patients experienced active CMV infections. Of these, 17 developed clinical symptoms. The diagnostic value of PMNLs and PBMCs viremia was determined in comparison to pp65 antigenemia, leukoDNAemia, plasma DNAemia, and detection of cytomegalic endothelial cells. In both PMNLs and PBMCs (with or without detectable endothelial cells), frequencies and levels of viremia were significantly higher among symptomatic patients. Regarding the occurrence of clinical CMV manifestations, the sensitivity of culture from PMNLs and from PBMCs fractions was 100%. Viremia in PBMCs, however, was far more specific (94%) than in PMNLs (74%). Cutoff values established previously for pp65 antigenemia and leukoDNAemia, standard markers in the laboratory, had similar specificity (96% each) to PBMCs viremia, but were less sensitive (88% each). Plasma DNA-emia was both less sensitive (82%) and less specific (69%) than PBMCs viremia. Detection of endothelemia showed maximal specificity (100%), but inferior sensitivity (47%). All patients had PBMCs viremia before the onset of symptoms. In conclusion, infectious CMV present in PBMCs may prove to be a determinant of clinical CMV manifestations in seropositive immunocompromised individuals. Factors involved in PBMCs tropism may help to understand the pathogenetic mechanisms of CMV dissemination in this group of patients.

Pulsed-field gel electrophoresis for the analysis of Listeria monocytogenes infection clusters after kidney transplantation

Listeria monocytogenes causes a rare, life-threatening infection in recipients of transplanted organs. We used cultures of blood and cerebrospinal fluid to characterize isolates and to distinguish cases in clusters from what might have been sporadic cases. From December 1994 to November 1995, six systemic L. monocytogenes infections occurred at our renal-transplantation unit. We confirmed the clinical diagnosis with blood and cerebrospinal fluid cultures and characterized the isolates retrospectively with pulsed-field gel electrophoresis (PFGE), phage-typing, and serotyping. We also performed an environmental investigation (food, drug, and stool). We took samples after the first two L. monocytogenes infections and then after cases three and four occurred. All patients recovered completely, and no graft was lost. Four patients had identical or genetically related L. monocytogenes isolates in PFGE (type A) and serotyping (type 1/2b). The other two had PFGE type B and G. L. monocytogenes was not detected in food or drug samples from patients on the renal-transplantation ward or in stool samples from the ward staff. It was concluded that PFGE allows sporadic cases and cluster cases of L. monocytogenes infection to be distinguished.

[Perioperative incidence of transfusions after allogenic kidney transplantation]

The requirement of blood transfusions was evaluated in a two compartment (retrospective/prospective) study in our renal transplantation program. Between July 1st, 1993 and December 31st, 1994 (observation period 1) we retrospectively investigated 110 patients with end stage renal disease and anemia undergoing kidney transplantation. Between January 1st, 1995 and December 31st, 1996 (observation period II) the requirement of blood transfusions was followed prospectively in 134 patients after allogenic renal transplantation. The amount of blood drawn for preoperative diagnostic investigations was in observation period 1 significantly higher (280 ml) than in observation period II (150 ml) (p = 0.02). For postoperative diagnostic tests in observation period II significantly less blood (240 ml) was needed than in observation period 1 (510 ml) (p = 0.01). The intraoperative blood loss was similar in both periods (170 ml vs. 190 ml; p = 0.6). The need for closer graft observation was the reason for significantly increased amount of blood transfusions in patients with delayed graft function. The number of blood transfusions was significant lower in patients with primary graft function (p = 0.0001). There was no correlation between blood transfusions and the use of ATG/OKT3, surgical complications and reoperations. With an improved management of blood drawing for diagnostic tests after allogenic kidney transplantation the number of perioperative blood transfusions can be reduced significantly.

Utility of major leukocyte subpopulations for monitoring secondary cytomegalovirus infections in renal-allograft recipients by PCR

The feasibility of the major peripheral blood leukocyte (PBL) subsets for use in qualitative and quantitative PCR to monitor secondary cytomegalovirus (CMV) infection and ganciclovir therapy was assessed with 188 blood samples derived from 40 CMV immunoglobulin G-positive renal-allograft recipients. In pp65 antigen-positive patients all leukocyte fractions, but only 79.5% of plasma preparations, were PCR positive. In pp65 antigen-negative samples from patients after antiviral treatment only 7.3% of polymorphonuclear cell (PMNL) samples, but 81.8% of peripheral blood mononuclear cells (PBMC), and 10.9% of plasma samples remained PCR positive. Similarly, in patients with latent infections only 5.0% of PMNL, but 51.7% of PBMC preparations, and 8.0% of plasma samples were PCR positive. Regarding patients with active CMV infection, CMV DNA copy numbers in PMNL correlated significantly with pp65 antigen-positive cell counts before and after onset of ganciclovir therapy. Significant differences in CMV DNA copy numbers in PMNL and plasma were observed (i) between patients with symptomatic infection and those with asymptomatic infection and (ii) between patients with active infection and those with latent infection. In contrast, PBMC harbored equally low CMV DNA levels both in patients with active infection and those with latent infections, and no decline of CMV DNA load in PBMC was observed during antiviral treatment. We conclude that detection of CMV DNA in PMNL, not in PBMC, is associated with active infections and is more sensitive than detection of CMV DNA in plasma. Negative PCR results for PMNL after antiviral therapy indicate recovery, and fewer unwanted positive results occur compared to PBMC and plasma. Therefore, purified PMNL should be preferred for analysis by qualitative CMV PCR to avoid unwanted positive results. The CMV DNA load in PBMC compared with that in PMNL is negligible during active infection, so mixed PBL are sufficient for use in quantitative PCR.

[Occurrence of lymphoceles after allogeneic kidney transplantation and their therapy]

We conducted a prospective evaluation of 301 consecutive renal transplants to define the prevalence and therapy of lymphoceles following renal transplantation. Using a management scheme, we identified in 52 patients (17.3%) perirenal fluid collections. Using this management scheme, we treated 47/52 patients conservatively. Only 5 (1.7%) patients required internal marsupialization. We conclude that groin lympho cysts after renal transplantation can be successfully treated with conservative methods.

Nosocomial infections by Listeria monocytogenes: analysis of a cluster of septicemias in immunocompromised patients

From December 1994 to November 1995 an unusual accumulation of Listeria infections occurred at the University Hospital Hamburg-Eppendorf, Germany. Eleven immunosuppressed patients from different departments developed septicemia due to Listeria monocytogenes during hospitalization. In a retrospective study, serotyping and pulsed-field gel electrophoresis revealed that six isolates were identical or genetically related. Four of them had been isolated from renal transplant recipients. Listeria monocytogenes was neither detected in food samples of the renal transplantation ward, nor in stool specimens obtained from the ward staff. There had been no close contacts among the infected patients. Before transplantation, the renal transplant recipients had been dialysed in different dialysis centers. Nosocomial foodborne transmission could not be proven but seems likely.

Minimal effect of delayed sample processing on results of quantitative PCR for cytomegalovirus DNA in leukocytes compared to results of an antigenemia assay

Quantitative cytomegalovirus antigenemia and DNAemia were determined in peripheral leukocytes of 25 patients stored for up to 72 h at room temperature (RT) and 4 degrees C before processing. Numbers of antigen-positive cells significantly decreased with time. The decline was greater at RT than at 4 degrees C. In contrast, no significant alterations in DNAemia occurred.

[Femoral arteriovenous fistula and transplant malfunction after allogeneic kidney transplantation. A case report]

This case report deals with the clinical history of a 52-year-old woman who suffered from delayed graft function and ischaemic pain after a technically successful renal transplantation. The past history of the patient revealed that coronary catheters had repeatedly been used for investigation and treatment of myocardial infarctions. The clinical investigation reported here revealed a typical auscultatory result with an arteriovenous (AV) fistula in the right upper limb. After performing a digital arterial angiography, an AV fistula between the femoral artery and vein was demonstrated. Operative occlusion of the fistula increased the perfusion of the kidney graft and the right limb. The patient recovered without wound infection and could leave the hospital with the transplanted kidney functioning well. This case report demonstrates that persistence of AV fistulas after angiographic investigations is rare. Operative occlusion of these lesions should be performed before kidney transplantation to avoid steal phenomena and disturbed would healing.

[Urologic complications after kidney transplantation. Experiences in a center with 539 recipients]

A total of 539 renal transplantations were performed at the Department of Urology of the University Hospital of Hamburg between 1984 and 1991. 132 (24.5%) patients developed urological complications (by definition, complications occurring as a result of the operative procedure). In 31 cases the transplants had to be removed secondary to urological complications, and 4 patients died of such complications (mortality 0.7%, lethality 3.0%). Urinary tract infections occurred in 13.2% of all patients during the first postoperative year and were by far the most frequent complication, followed by haematomas, which occurred in 9.6%. The incidence of urinary tract and wound infections was significantly reduced during the 8-year period studied by improving antibiotic prophylaxis and adopting a strategy of early removal of indwelling catheters (P < 0.05). Stenting the ureteroneocystostomy with a double-J stent instead of an external ureteral catheter resulted in a definite decrease in the incidence of ureteral leaks (P < 0.05). Continuous control of operative results and efforts to improve operative and perioperative strategies make it possible to reduce the incidence of urological complications in renal transplantation and thus result in an improved graft function and patient survival.

[Diagnosis of graft rejection]

The topic of renal transplant rejection diagnosis is reviewed. The immunological and morphological findings and the clinical presentation of hyperacute, acute and chronic rejection are described. The indications for, and the value and limitations of diagnostic techniques such as core biopsy, fine-needle aspiration cytology, duplex Doppler sonography and immunological findings are analyzed. Early diagnosis and treatment are regarded as the central aim to prevent graft loss through rejection.

Endo-urological cold-knife incision for ureteral stenosis after renal transplantation

Cold-knife incision of stenoses in the transplant ureter was performed in 11 patients with upper urinary tract obstruction in renal transplants. The operations were complicated by bleeding in 2 patients and the graft had to be removed in 1 of them. The stenoses could be treated successfully in 10 of the 11 patients (91%) and the mean serum creatinine concentration decreased significantly from 3.4 to 1.8 mg./dl. After a mean of 26 months only 1 obstruction recurred, so the long-term success rate was 82%. Because of the favorable long-term results and the low incidence of complications, we recommend endo-urological cold-knife incision of ureteral stenosis as the first-line treatment for upper urinary tract obstruction in renal transplants.

[Cytomegalovirus diseases following allogenic kidney transplantation]

Lymphotrophic virus infections, especially when they are caused by the cytomegalovirus, are severe complications after allogenic organ transplantation. First infections are mainly caused by donation of CMV-positive organs to CMV negative recipients. The regular incubation time of 30 to 40 days can be significantly shorter after therapeutic application with high dose prednisone or mono/polyclonal antibodies for treatment of rejection. The spectrum of clinical signs of the CMV-disease after organ transplantation can range between serological alterations and the lethal CMV-syndrome. The early recognition of virus-dependent clinical symptoms and the establishment of the diagnosis are the first conditions for the treatment, consisting in reduction of the immunosuppressive medication and application of ganciclovir, a CMV-specific virusstatic agent. The prophylactic application of CMV-hyperimmunoglobulin is discussed controversially. A very important aspect of CMV-disease in the long-term follow-up is the influence of this virus infection on the development of chronic organ rejection, which could be demonstrated in animal studies by application of the Marek virus and which was seen in pathomorphological samples of transplant biopsies. Future diagnostic and therapeutic strategies, which aim at the prolongation of the patient's survival and the transplant function have to consider the influence of virus infections as a severe risk-factor, as the transplantation of CMV-negative organs to CMV-negative recipients is more the exception than the rule.

Hemofiltration in myoglobinuric acute renal failure

The frequency of myoglobinuric renal failure is estimated between 8 and 20%. Despite early onset of therapy often the use of renal substitution by hemodialysis or hemofiltration is required. This study of the clinical course of nine patients with myoglobinuric acute renal failure reveals continuous arterio-venous hemofiltration (CAVH) to have an effective clearance for myoglobin. Thus, the time until recovery of renal function as well as the frequency of secondary complications in rhabdomyolysis induced acute renal failure can be distinctly reduced.

Results of a long-term administration of omega-3 fatty acids in haemodialysis patients with dyslipoproteinaemia

In this study we evaluated the effect of a daily administration of 1 g salmon-oil concentrate containing 0.2 g eicosapentaenoic acid (EPA) on the blood pressure, serum cholesterol, HDL and LDL cholesterol, triglycerides and magnesium of ten patients on chronic haemodialysis. Systolic and diastolic blood pressure values decreased significantly from 156 +/- 27.7/84 +/- 14.3 to 140 +/- 22.8/75.6 +/- 8.21 mmHg. Concordantly, mean arterial pressure (MAP) decreased significantly from 108 to 96 mmHg. Total serum cholesterol decreased significantly by 64%, HDL cholesterol increased by 47% (P less than 0.001). Serum triglyceride values decreased significantly to 48%. There was a distinct decline of magnesium from 1.42 +/- 0.27 to 1.28 +/- 0.13 mg/dl (P less than 0.001). According to these results, the administration of omega-3 fatty acids may be considered as a reasonable approach in the treatment of dyslipoproteinaemia in patients on continuous haemodialysis.

[Duplex sonography in the diagnosis of renal artery stenoses following allogenic kidney transplantation]

Posttransplant renal artery stenosis (TRAS) as a cause of secondary hypertension is reported with an incidence of 1 to 10%. Early diagnosis of TRAS should be made by non-nephrotoxic and non-invasive means to lower the risk of hypertension. One to 66 months after kidney transplantation 335 patients underwent Duplex-scanning, 38 of cases for clinical tentative diagnosis of TRAS. Parameters for clinical diagnosis of TRAS were diastolic hypertension greater than 100 mm Hg with resistance to therapy (A), an abdominal bruit over the transplant (B), disturbance of renal function (serum-creatinine greater than 2 mg/dl) (C). Admission to study followed the parameter-combination A + B. A + C, B + C. Rejection crisis was excluded in 18/38 cases by fine needle biopsy, cyclosporine over-dosage was negative in 38/38 cases, 20/38 cases had normal renal function. Duplex-/Doppler-ultrasound criteria for TRAS were systolic peak velocity greater than 100 cm/s-1 and broadening of the diastolic frequency spectra with a smooth decline in diastole to an elevated diastolic level. In 32/38 cases (84.2%, n = 38) diagnosis of TRAS was made by duplex-scanning, angiography confirmed the result in 30/32 cases (93.75%, n = 32); sensitivity was 88.2% with a specificity of 66.6%. Duplex-scanning as a primary diagnostic means for TRAS seems a promising method compared to e.g. radionuclide imaging or angiography. Duplex-scanning is a non-nephrotoxic and non-invasive procedure repeatable at any time with only few preliminary conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

[Rare variants and unusual course of Cushing's syndrome]

Cushing's syndrome is a rarely observed disease with a poor prognosis when not treated appropriately. Knowledge of clinical features of the different forms of the disease together with a specific and subtle method of cortisol detection is indispensable for an early out-patient diagnostic program. In this study the characteristic features of the rare benign and malignant forms of Cushing's syndrome are presented in typical case-reports. As it has been proven in clinical experience, the necessary diagnostic measures for clarification of the syndrome consists of only few methods reliable concerning their diagnostic validity. The success of any curative treatment of the benign forms or any palliative measure of the malignant forms essentially depends on early diagnosis and differentiation of the various appearances of Cushing's disease.

Primary aldosteronism by carcinoma of the adrenal cortex

A 58-year-old white woman with hypertension and severe hypokalemia was found to have a carcinoma of the left adrenal gland. Plasma renin activity was constantly under the normal limit, while plasma aldosterone levels were pathologically elevated. Plasma cortisol (8:00 a.m.) and excretion rates of urinary free cortisol were within the normal range. After an adrenalectomy, relapsing excessive aldosterone secretion was successfully treated with opDDD (Lysodrene). Ten months after the diagnosis was established, the patient died from a bleeding liver metastasis.

[Ambulatory 24-hour blood pressure monitoring before and after dilatation of renal artery stenoses]

The time course of blood pressure reduction after transluminal dilatation of renal artery stenoses was investigated by repeated 24 h blood pressure monitoring in 17 patients with renovascular hypertension. The results of treatment were compared for the different types of stenoses. The diurnal and nocturnal variations in blood pressure were not altered. The mean blood pressure in all patients during daytime (0800-2000) was 160 +/- 13/99 +/- 7 mm Hg (mean +/- SD syst./diast.) before dilatation, 151 +/- 10/91 +/- 6 mm Hg on the day of dilatation (p syst. less than 0.01, p diast. less than 0.01) and 151 +/- 9/91 +/- 6 mm Hg 1-4 weeks after. Blood pressure was further reduced to 137 +/- 12/84 +/- 8 mm Hg after 9-11 months despite a reduction in drug treatment (p syst. less than 0.001, p diast. less than 0.001). After 9-11 months the reduction in blood pressure (0800-2000) was 31/21 mm Hg (mean syst./diast. reduction) in the patients with only one kidney and 29/20 mm Hg in subjects with fibromuscular dysplasia. In the patients with arteriosclerotic renal artery stenoses who had two kidneys the blood pressure was reduced by only 18/11 mm Hg. The results of repeated ambulatory blood pressure monitoring indicate that the initial fall in blood pressure after dilatation of renal artery stenoses is followed by a delayed further reduction. Subjects with only one kidney and patients with fibromuscular dysplasia show the most effective reduction in blood pressure after dilatation of renal artery stenoses.

[Diuretic-resistant hypertension. Effect of an additional daily single dose of a ACE inhibitor]

The effect of additional administration of a low dose of an ACE inhibitor when blood pressure is inadequately controlled by a diuretic alone was investigated in 12 essential hypertensive patients. 24 h blood pressure monitorings were performed with portable automatic recording devices before and after treatment with 50 mg hydrochlorothiazide (HCT) and after additional administration of 25 mg captopril. The frequency of blood pressure readings exceeding 160/95 mm Hg within 24 hours was reduced in 11 of the 12 patients after administration of the ACE inhibitor. Mean blood pressure during daytime was 158 +/- 13 / 100 +/- 8 mm Hg without treatment, 151 +/- 11 / 93 +/- 8 mm Hg during HCT alone and 140 +/- 13 / 88 +/- 9 mm Hg during HCT + captopril. The results show that in a large proportion of hypertensives inadequately controlled by a diuretic alone, the addition of a low dose of an ACE inhibitor (captopril, 25 mg once daily) may normalize the blood pressure.

Treatment of resistant hypertension by phlebotomy

In 15 essential hypertensives resistant against a standard triple combination of antihypertensive drugs phlebotomy was performed. Mean arterial pressure was lowered from 140.1 +/- 12.2 mm Hg to 123.8 +/- 14.9 mm Hg after 14 days. No serious side effects were observed. The duration of the hypotensive effect of phlebotomy was about 4 weeks. Phlebotomy can be used in addition to drug treatment in resistant essential hypertension.

Secondary hypertension and neurofibromatosis: bilateral renal artery stenosis and coarctation of the abdominal aorta

A 34-year-old white man with generalized neurofibromatosis was found to have severe renal vascular hypertension due to a coarctation of the abdominal aorta and bilateral renal artery stenosis with saccular aneurysms. Increased renal venous renin activity showed the active involvement of the renin-angiotensin system in maintaining the hypertension. Because the patient refused surgical treatment, antihypertensive treatment with Captopril, a specific inhibitor of the angiotensin converting enzyme was used, resulting in normal blood pressure being restored over an 18 month observation period.

Adrenalectomy in primary aldosteronism: a long-term follow-up study

The effect of unilateral adrenalectomy in primary aldosteronism was analyzed in 38 patients with unilateral adenoma, 12 cases with idiopathic bilateral hyperplasia and 1 patient suffering from an aldosterone-producing carcinoma. Responses to surgery differed markedly. In all 38 adenoma cases plasma aldosterone dropped to normal levels and remained within normal range during a mean follow-up period of 75 +/- 12 months. 23 (61%) of these patients became normotensive without medication and thus could be classified as definitely cured. 34% (13 patients) improved (normotensive under medical treatment) and only 2 cases (5%) remained hypertensive despite sufficient medical treatment. In the hyperplasia group, however, the effect of adrenalectomy was disappointing. None of these subjects showed a long-lasting normalization of aldosterone secretion. A temporary remission for no more than 3-4 months was achieved in only 3 patients. In a fourth case with macronodular hyperplasia, primary aldosteronism relapsed after a 6-year period of normal blood pressure and aldosterone values. Therefore, 6 years after adrenalectomy no hyperplasia patient was definitely cured in contrast to 61% of the adenoma cases. The problems in the management of hypertension in adrenal hyperplasia are furthermore documented by a poorer blood pressure control despite antihypertensive medication and a high rate of vascular complications. During the follow-up, 3 of 12 hyperplasia patients experienced a cerebrovascular event and 1 a myocardial infarction.

Pathogenetic aspects of hypertension in Cushing's syndrome

Abnormalities of the renin-angiotensin-aldosterone system (RAAS) were observed in hypertensive patients suffering from Cushing's syndrome. In 12 patients with different etiology of Cushing's syndrome renin substrate concentration and urinary-free cortisol, as well as the circadian rhythms of plasma cortisol, aldosterone and plasma renin activity were measured. Plasma renin substrate concentrations were found elevated in all but 1 patient, while plasma renin activity was elevated, normal or lowered. Plasma aldosterone values were found in the lower normal range. A physiological rhythm of cortisol secretion was not observed in any patient with Cushing's syndrome, while plasma aldosterone was secreted episodically mostly within the normal range. We conclude that changes of the RAAS may not be predominantly responsive for hypertension in Cushing's syndrome; other factors like circulating catecholamines are probably of greater importance for the pathogenesis of blood pressure elevation in hypercortisolemic patients.

Primary aldosteronism: diagnosis and noninvasive lateralization procedures

In 72 patients with primary aldosteronism who were classified on the basis of adrenal pathology after adrenalectomy, analysis of routine clinical and laboratory data, of supine and upright plasma aldosterone, and of plasma renin activity were of limited value in differentiating patients with aldosterone-producing adenoma(s) (APA, n = 59) from those with idiopathic adrenal hyperplasia (IAH, n = 13). Normokalemic aldosteronism occurred in 6 patients (3 APA, 3 IAH). A correct classification of the adrenal lesion(s) was obtained in 80% of the patients by computed tomography and only in 69% by adrenal scintiscan. In addition, adrenal scintiscan was hampered by a relatively high rate of incorrect results independent of whether dexamethasone was used or not. Small adenomas (less than 1 cm) and more often adrenal hyperplasia may escape visualization by computed tomography.

Captopril in Cushing's syndrome

To analyse the role of the renin angiotensin system in the pathogenesis of hypertension in Cushing's syndrome ten patients with hypercorticism (five with pituitary hypothalamic dysfunction, three with adrenal adenomas and two with adrenal carcinomas) received a single oral dose of 25 mg captopril. Mean arterial pressure was then determined at short intervals over periods of up to 240 min. Plasma renin activity (PRA) was measured immediately before the administration of captopril. Eleven patients with severe essential hypertension, who showed a comparable distribution of basal PRA values, served as a control. Patients with elevated basal PRA values (greater than 3 ng/ml X 3 h) showed, both in the subgroup of cases with essential hypertension and in that with Cushing's syndrome, a statistically significant fall (P less than 0.05-P less than 0.001) in mean arterial pressure, the decrease being slightly more pronounced in essential hypertensives. On the other hand patients with normal PRA values (less than or equal to ng/ml X 3 h) exhibited only a minor fall in mean arterial pressure reaching statistical significance (P less than 0.05) only after 60 min (essential hypertension) and 180 min (Cushing's syndrome), respectively. Our results document that in patients with Cushing's syndrome the effect of captopril seems to be determined by the activity of the renin angiotensin system. Thus, in a substantial number of patients with hypercorticism, the renin angiotensin system may be an important factor in the pathogenesis of hypertension, whereas in patients with low PRA values other factors like oversecretion of mineralocorticoids may be responsible for the observed blood pressure increases.

Primary aldosteronism due to adrenal carcinomas

In the present study two patients with aldosterone-producing adrenal carcinomas are reported. The clinical features were characterized by hypertension and severe hypokalemia with muscular weakness, flaccid paralysis of arms and legs, diarrhea and polyuria. In both cases excessively high plasma aldosterone levels and suppressed plasma renin activity were found. In contrast to most other cases with aldosterone-secreting tumours plasma cortisol, urinary free cortisol excretion, 17-hydroxy- and 17-ketosteroids were in the normal range. There was no clinical evidence of oversecretion of sex hormones. After adrenalectomy blood pressure and serum potassium normalized and the clinical symptoms disappeared. Plasma aldosterone and urinary aldosterone secretion returned to normal, while plasma renin activity remained low. Three and a half and 6 months later primary aldosteronism and the associated clinical symptoms reappeared due to hormonally active metastases. After introducing the antitumour drug o,p'-DDD in patient 1 aldosterone secretion normalized and the clinical status of the patient markedly improved. However, 10 months after diagnosis the patient died due to a haemorrhage from a liver metastasis. In patient 2 tumour-invaded regional lymph nodes were surgically removed with only minor changes in the hormone pattern.

Angiotensin II binding to human mononuclear cells: receptor or free fluid endocytosis?

It has recently been claimed that there are angiotensin II (ANG II) receptors on human mononuclear cells and on platelets and this has been used for investigating the regulation of the renin-angiotensin system in hypertension. We here show the following. Binding kinetics of 125I-labelled ANG II and [3H]ANG II to mononuclear cells were slow (maximum at 90 min) and the same as for [3H]-inulin. As with [3H]inulin there was no binding at 4 degrees C. Release from the cells was slow and incomplete (about 30% after 15 min, 60% after 60 min). Binding was not saturable over a range from 10(-12) to 10(-6) mol of ANG II/l, about 8% of offered peptide being bound at all concentrations. Various inhibitors of free fluid endocytosis exhibited the same inhibition pattern of ANG II binding to mononuclear cells. Therefore uptake of ANG II into mononuclear cells displayed all the features of free fluid endocytosis. ANG II was degraded by carboxypeptidase A. When this degradation was prevented by D-phenylalanine, no binding occurred. In platelet preparations contaminated by 0.3-5% of mononuclear cells, 125I-labelled ANG II was degraded as well. Free fluid endocytosis of the degradation product strongly depended on the percentage of contaminating mononuclear cells. We conclude that there are no ANG II receptors on human mononuclear cells and that their presence on human platelets is doubtful.

[Rare forms of hypertension (neurofibromatosis and cholesterol embolization]

In the past year 5 patients with uncommon secondary hypertension have been observed at the Medical Clinic, Cantonal Hospital of St Gall, Switzerland. Two patients had generalized neurofibromatosis with specific vascular lesions of the renal arteries, while 3 older patients showed clinical and morphologic signs of repeated renal cholesterol embolization. Experience with these 5 patients shows that angiography should chiefly be used in young patients with suspected secondary hypertension. Older patients with common vascular sclerosis should undergo angiography only where the indication is urgent, in view of the risk of renal cholesterol embolization. In 3 of 5 patients a lasting improvement in hypertension was achieved by antihypertensive drug therapy. Two older patients with cholesterol embolization died from complications such as uremia and therapy-resistant hypertension.