Arteriovenous fistula and prolonged hematuria after renal biopsy: treatment with epsilon aminocaproic acid

A patient with membranoproliferative glomerulonephritis and mild hypertension is described who, after a renal biopsy, developed an arteriovenous fistula and then severe continuous hematuria from the seventh to the 38th postbiopsy day. Treatment with epsilon aminocaproic acid was associated with rapid and permanent cessation of bleeding, gradual improvement in renal function, and disappearance of the renal artery bruit. No complications were encountered.     

Hypertension,hypokalemia, hyporeninemia and severe target organ damage.

A 51-year-old woman with a 20-year history of severe hypertension and target organ damage had nondiuretic hypokalemia, kaluresis, suppressed plasma renin activity and elevated urinary excretion of aldosterone. Renal arteriography demonstrated unilateral renal artery stenosis secondary to fibromuscular hyperplasia. Blood pressure responded only minimally to almost all antihypertensive agents. Spironolactone, 300 to 400 mg/d, produced distinct improvement in blood pressure, which was maintained for 13 months.     

Apport de la scintigraphie rénale avec test au captopril dans l’exploration de l’hypertension artérielle rénovasculaire : à propos d’un cas

IntroductionDynamic renal scintigraphy with ^99mTc-DTPA and captopril test is a non-invasive functional method for the diagnosis of renovascular hypertension. It allows differentiating between hypertension induced by renal arterial stenosis from primary arterial hypertension with an incidental stenosis.Case reportA 14-year-old girl, without previous medical history, developed a severe arterial hypertension with cephalgias and ears buzzing. Auscultation revealed a murmur in the left lumbar pit. Renal angiography objectified a stenosis of the infrarenal aorta due to a circumferential parietal thickening associated to renal arteries stenosis more marked in the left side. Dynamic renal scintigraphy after administration of captopril highlighted a marked collapse of the rate of tracer uptake exceeding 40% on the left side with an increase in the time of collecting on the right side testifying a frankly positive test prevailing on the left. A transluminal angioplasty of the left renal artery and a revascularisation surgery on the right side were carried out. The evolution was marked by an improvement of blood pressure figures.DiscussionDynamic renal scintigraphy using ^99mTc-DTPA with captopril test constitutes a non-invasive process with a low dosimetry for the patients. Its principal goal is to affirm the role of renovascular stenosis in the origin of arterial hypertension and to determine which hypertensive patients with renal arterial stenosis can be treated successfully by surgical or endoscopic revascularisation of the kidney.     

Renal Artery Stenosis Predicts Coronary Artery Disease in Patients with Hypertension

In hypertensive patients with indication of renal arteriography to investigate renal artery stenosis (RAS) there are no recommendations regarding when to investigate coronary artery disease (CAD). Moreover, the predictors of CAD in patients with RAS are not clear. We aimed to evaluate the frequency and the determinants of CAD in hypertensive patients referred to renal angiography. Eighty-two consecutive patients with high clinical risk suggesting the presence of RAS systematically underwent renal angiography and coronary angiography during the same procedure. Significant arterial stenosis was defined by an obstruction≥70% to both renal and coronary territories. Significant CAD was present in 32/82 (39%) and significant RAS in 32/82 (39%) patients. Both CAD and RAS were present in 25.6% from the 82 patients. Patients with severe CAD were older (63±12 vs. 56±13 years; p = 0.03) and had more angina (41 vs. 16%; p = 0.013) compared to patients without severe CAD. Significant RAS was associated with an increased frequency of severe CAD compared to patients without significant RAS (66% vs. 22%, respectively; p<0.001). Myocardial scintigraphy showed ischemia in 21.8% of the patients with CAD. Binary logistic regression analysis showed that RAS≥70% was independently associated with CAD≥70% (OR: 11.48; 95% CI 3.2–40.2; p<0.001), even in patients without angina (OR: 13.48; 95%CI 2.6–12.1; p<0.001). Even considering a small number of patients with significant RAS, we conclude that in hypertensive patients referred to renal angiography, RAS≥70% may be a strong predictor of severe CAD, independently of angina, and dual investigation should be considered.     

Symptomatic carotid ischaemic events: safest and most cost effective way of selecting patients for angiography,before carotid endarterectomy.

OBJECTIVE: To determine the safest, least costly, and most effective way to select patients with symptomatic carotid ischaemic events for carotid angiography before carotid endarterectomy. DESIGN: Prospective cohort study. SETTING: University departments of clinical neurosciences and clinical neurology. PATIENTS: 485 Patients with carotid territory transient ischaemic attacks of the brain (n = 224) or eye (n = 162) or retinal infarction (n = 99) were referred to a single neurologist between 1976 and 1986. INTERVENTIONS: Clinical examination by auscultation over the precordium, supraclavicular fossae, and neck vessels (all patients). Cerebral angiography of patients suitable for carotid endarterectomy. MAIN OUTCOME MEASURES: Financial cost and number of disabling strokes after angiography. RESULTS: 296 Patients were investigated by cerebral angiography. Ischaemic symptoms had occurred in the distribution of 298 internal carotid arteries (symptomatic) that were imaged, two patients having bilateral symptoms. The presence or absence of a carotid bruit and the maximum percentage diameter stenosis of the origin of the symptomatic internal carotid artery were correlated. The prevalence of mild disease (diameter stenosis greater than or equal to 25%) of the symptomatic internal carotid artery was 57%, and if an ipsilateral carotid bruit was heard the probability of mild stenosis rose to 92%. The prevalence of moderate disease of the symptomatic internal carotid artery (stenosis greater than or equal to 50%) was 39%, and if a bruit was heard the probability doubled to 78%. The prevalence of severe internal carotid disease (stenosis greater than or equal to 75%) was 22%, and if a bruit was heard the probability was more than double, at 49%. The direct cost to both the NHS and the private health sector of investigating patients with symptomatic carotid ischaemia was estimated for several strategies of carotid artery imaging and expressed in terms of financial cost and number of strokes after angiography incurred in detecting all patients with diameter stenosis of the symptomatic internal carotid artery of greater than or equal to 25%, 50%, or 75%. To detect diameter stenosis of the internal carotid artery of greater than or equal to 25% it is most cost effective to proceed directly to cerebral angiography in patients with a carotid bruit over the symptomatic carotid bifurcation and to screen patients without a carotid bruit by duplex carotid ultrasonography; patients in whom duplex ultrasonography discloses stenosis of greater than or equal to 25% are then referred for cerebral angiography. To detect only more severe internal carotid disease (stenosis of greater than or equal to 50%) the same policy applies, unless the local duplex ultrasonographic service is particularly efficient and reliable, when it is probably most cost effective and safer to screen all patients by this method irrespective of the findings on cervical auscultation. To detect stenosis of 75% or greater it is most cost effective to screen all patients with duplex ultrasonography, whether a carotid bruit is present or not, because this approach reduces the number of angiograms required, is the least expensive, and results in the least number of strokes after angiography. CONCLUSIONS: Patients selection for cerebral angiography before carotid endarterectomy needs to be appropriate and cost effective. Sound clinical evaluation and duplex carotid ultrasound are required. The findings of this study should not be applied to other medical centres without first considering possible differences in the prevalence of carotid artery disease, the efficiency and reliability of duplex ultrasonography, the local complication rates of cerebral angiography, and the local costs of the imaging procedures.     

Fetuin,Matrix-Gla Protein and Osteopontin in Calcification of Renal Allografts

Background

Calcification of renal allografts is common in the first year after transplantation and is related to hyperparathyroidism. It is associated with an impaired long-term function of the graft (Am J Transplant 5∶1934-41, 2005). Aim of this study is to examine the role of the anti-calcifying/calcifying factors in the pathophysiology of renal allograft calcification.

Methods

We analyzed protocol allograft biopsies, blood and urine samples of 31 patients with and 27 patients without allograft calcification taken at 6 weeks, 3 and 6 months after transplantation. Patient demographical data, cold ischemia time, initial graft function and donor characteristics were comparable between the two groups. Biopsies were stained for osteopontin, fetuin, and matrix-gla-protein. Serum and urine electrolytes, matrix-gla-protein, fetuin, Vitamin D and intact parathyroid hormone in serum and osteopontin (OPN) in urine were examined.

Results

Serum levels of fetuin and matrix-Gla protein as well as urinary levels of OPN showed specific time dependent changes (6 weeks vs. 3 months vs. 6 months; all p<0.0001). In patients with calcifications, urinary levels of OPN were decreased by 55% at 6 weeks and increased thereafter, showing 54% higher levels at 6 months compared to patients without calcification (6 weeks: p<0.01, 6 months: p<0.05). Local protein expression of fetuin-A, matrix-Gla protein and OPN in the graft was specifically increased around calcified plaques, without differences in the mRNA tissue expression.

Conclusion

Anticalcifying factors show significant changes in the early phase after renal transplantation, which may be important for the prevention of allograft calcification. The differences in OPN indicate an involvement of this factor in the regulation of calcification.     

Evaluation of the Urea Washout Pyelogram and Urography in the Assessment of Renovascular Hypertension

The urea washout (UWT) modification of the intravenous pyelogram was used to study 146 hypertensive patients in order to detect the presence of significant renovascular abnormalities. A positive result was obtained in 55 patients and direct confirmation of main renal artery stenoses by selective renal arteriography was obtained in 26. Bilateral abnormalities were confirmed in seven of the 26 patients. No false-negative results were encountered. The usefulness of this test as a comprehensive screening test is outlined. It demonstrated a high degree of accuracy in the diagnosis of significant unilateral or bilateral main renal artery stenosis in addition to the detection of diffuse intrarenal arteriolar disease. It was of value in the postoperative assessment of operative repair of main renal artery defects. The urea washout test embodies both an anatomical and a physiological approach in the roentgen diagnosis of curable renovascular hypertension. The altered physiology resulting from significant main renal artery stenosis makes possible the use of the urea washout intravenous pyelogram. The value of other forms of intravenous pyelography is described.     

Nocturnal polyuria and saluresis in renal allograft recipients.

The evolution of nocturnal polyuria and saluresis in renal allograft recipients was studied by comparing the day to night (D:N) ratios of urine volume and sodium excretion in 15 patients who had undergone transplantation less than one year previously (recent-transplant group) with those in 11 patients who had undergone transplantation at least one year previously. Eleven patients with chronic renal failure and 12 normal subjects served as controls. Patients in the recent-transplant group had significantly lower D:N ratios of urine volume and sodium excretion than the patients who had undergone transplantation at least a year before, while the ratios in this last group did not differ significantly from those in the normal subjects. Nocturnal polyuria and saluresis gradually subsided in five patients studied for three months. Chronic renal failure and uraemic autonomic neuropathy were unlikely causes of the nocturia. The patients in the recent-transplant group had significantly lower D:N ratios of urine volume than the controls with chronic renal failure, and the mean Valsalva ratio in eight of them was not significantly different from that in the normal subjects. An undue sensitivity of renal allografts to postural influences was proposed.     

Effect of prostaglandin A1 infusion in hypertensive patients with renal artery stenosis

Clinical data, arteriographic findings, peripheral and renal vein plasma renin activity (PRA) studies and responses to prostaglandin A1 infusion are presented from observations in seven hypertensive patients with renal artery stenosis. PGA1 infusion caused an increase in PRA and urine sodium excretion but no significant change in blood pressure. Exaggerated increases in PRA were observed in five patients. With cessation of PGA1 infusion PRA returned toward pre-infusion levels. In two patients bilateral renal and peripheral vein PRA's were determined before and during PGA1 infusion. PGA1 caused a greater increase in renal vein PRA than in peripheral vein PRA indicating a direct enhancement of renin secretion. These studies indicate possible relationships between the vasoactive prostaglandins and the renin-angiotensin system in the pathogenesis of hypertension due to renal artery stenosis.     

组织相容性Ⅰ类相关链A位点基因多态性在预判肾移植物排斥中的意义

目的 研究组织相容性Ⅰ类相关链A位点(MICA)基因多态性和抗MICA特异性抗体在肾移植排斥反应发生中的意义.方法 采用免疫磁珠液相芯片技术对40例肾移植患者在移植术前和移植术后1个月、3个月、6个月、1年和2年动态检测抗MICA抗体的特异性和阳性分值的变化,同时采用SSOP方法分析16对肾移植供受者的MICA基因分型...     

Effect of losartan on insulin plasma concentrations and LPL activity in adipose tissue of hypertensive rats.

The aim of this study is to determine the effect of losartan on insulin and angiotensin II (Ang II) concentrations in plasma as well as on lipoprotein lipase activity (LPL) and angiotensin II content in the adipose tissue of hypertensive rats. Fifty male rats were divided in five groups. Group A served as controls. Group B underwent renal artery stenosis. Group C were administered losartan (10 mg/kg/day) per os, while rats in group D were submitted to renal artery stenosis and were treated with losartan as above. Group E was used as sham-operated control. The animals were sacrificed at day 21. Blood samples were collected, and perirenal adipose tissue was isolated. Furthermore, adrenal's were removed and their relative weight (adrenal weight/body weight) was used as an index of sympathetic stimulation. According to our results, renovascular hypertension resulted in lower insulin concentrations and higher Ang II content in plasma. In hypertensive rats, LPL activity was decreased, while the adrenals' relative weight was elevated. On the other hand, losartan administration resulted in normalization of insulin concentrations in plasma and adrenals' relative weight, with consequent up regulation of LPL activity in adipose tissue. In conclusion, renovascular hypertension interferes in lipid metabolism by reducing LPL activity in adipose tissue, while losartan administration reverses this effect by enhancing insulin release and reducing sympathetic nervous system (SNS) stimulation.     

Effect of prostaglandin A1 infusion in hypertensive patients with renal artery stenosis

Clinical data, arteriographic findings, peripheral and renal vein plasma renin activity (PRA) studies and responses to prostaglandin A₁ infusion are presented from observations in seven hypertensive patients with renal artery stenosis. PGA₁ infusion caused an increase in PRA and urine sodium excretion but no significant change in blood pressure. Exaggerated increases in PRA were observed in five patients. With cessation of PGA₁ infusion PRA returned toward pre-infusion levels. In two patients bilateral renal and peripheral vein PRA's were determined before and during PGA₁ infusion. PGA₁ caused a greater increase in renal vein PRA than in peripheral vein PRA indicating a direct enhancement of renin secretion. These studies indicate possible relationships between the vasoactive prostaglandins and the renin-angiotensin system in the pathogenesis of hypertension due to renal artery stenosis.     

Does Lower Limb Exercise Worsen Renal Artery Hemodynamics in Patients with Abdominal Aortic Aneurysm?

Renal artery stenosis (RAS) and renal complications emerge in some patients after endovascular aneurysm repair (EVAR) to treat abdominal aorta aneurysm (AAA). The mechanisms for the causes of these problems are not clear. We hypothesized that for EVAR patients, lower limb exercise could negatively influence the physiology of the renal artery and the renal function, by decreasing the blood flow velocity and changing the hemodynamics in the renal arteries. To evaluate this hypothesis, pre- and post-operative models of the abdominal aorta were reconstructed based on CT images. The hemodynamic environment was numerically simulated under rest and lower limb exercise conditions. The results revealed that in the renal arteries, lower limb exercise decreased the wall shear stress (WSS), increased the oscillatory shear index (OSI) and increased the relative residence time (RRT). EVAR further enhanced these effects. Because these parameters are related to artery stenosis and atherosclerosis, this preliminary study concluded that lower limb exercise may increase the potential risk of inducing renal artery stenosis and renal complications for AAA patients. This finding could help elucidate the mechanism of renal artery stenosis and renal complications after EVAR and warn us to reconsider the management and nursing care of AAA patients.     

O‐8FALSE NEGATIVE BRONCHIAL CYTOLOGY

Introduction: BK virus nephropathy is an emerging cause of renal transplant failure accounting for allograft loss in 45–50% of recipients between 2–60 months post‐transplantation. The Renal Transplant Unit in Royal Free Hospital has devised a local surveillance programme for screening renal transplant patients at weekly intervals by urinary cytology (UC) and electron microscopy (EM), and confirmation of positive results by plasma PCR and allograft biopsy. Objective: (i) To monitor the implementation of local guidelines; (ii) To compare UC with EM and (iii) To identify areas for improvement. Methods: Decoy cell and EM positive cases were retrieved from the WinPath database for new renal transplant recipients (n = 55) during 1^st November 2004 to 31^st October 2005 in Royal Free Hospital. Plasma PCR was retrieved for positive cases. Results: Up to eight samples were sent for UC at random intervals from 47 patients, and up to 7 were sent for EM from 42 patients. Eleven were UC‐positive and one was EM‐positive. PCR was not requested in UC‐positive cases and 3 out of 10 were positive retrospectively. The EM‐positive case was PCR‐positive but UC‐negative. Discussion: Urine Cytology is more appropriate and cost effective for screening than Electron Microscopy. During the period covered by this audit, samples were sent in an inconsistent fashion after allograft dysfunction rather than for screening. A screening protocol has been agreed and a re‐audit is planned.     

Renal extraction of circulating adiponectin in patients with renovascular hypertension

BACKGROUND: Patients with chronic renal failure are characterized by an elevated plasma adiponectin concentration, which is significantly lowered after successful kidney transplantation. The direct renal clearance and extraction of adiponectin have not yet been documented in humans. Therefore the aim of the study was to estimate separate kidney extraction of adiponectin, by measuring its concentration in the aorta and both renal veins, in patients with renovascular hypertension caused by unilateral renal artery stenosis. METHODS: In 30 patients with significant (> 70%) unilateral renal artery stenosis, plasma adiponectin was measured in blood samples taken from the aorta, both renal veins and the vena cava inferior below the orifices of the renal veins. RESULTS: Renal venous plasma adiponectin concentrations (both from the kidney with renal artery stenosis and from the contralateral organ) were only numerically lower than the concentrations measured in the aorta (11.10 [8.65-13.56]; 11.12 [8.81-13.42]; 11.35 [8.90-13.80] microg/ml, respectively). Fractional extraction of adiponectin was 5.0 [-1.6-11.0]% in the kidney with renal artery stenosis and 3.0 [-2.4-9.01% in the contralateral "normal" kidney. Slightly higher concentrations of plasma adiponectin were observed in the vena cava inferior below the orifices of the renal veins (11.79 [9.14-14.44] microg/ml). In patients with unilateral renal artery stenosis significant negative correlations were found between plasma adiponectin concentration obtained from the vena cava inferior below the orifices of renal veins and eGFR (r = -0.38; p < 0.05), systolic (r = -0.71; p < 0.0001) and diastolic blood pressure (r = -0.40; p < 0.04), as well as serum triglyceride concentrations (r = -0.64; p < 0.001). CONCLUSION: The findings indicate that the fractional renal extraction of adiponectin is rather low.     

Pre-Transplant Donor-Specific T-Cell Alloreactivity Is Strongly Associated with Early Acute Cellular Rejection in Kidney Transplant Recipients Not Receiving T-Cell Depleting Induction Therapy

Preformed T-cell immune-sensitization should most likely impact allograft outcome during the initial period after kidney transplantation, since donor-specific memory T-cells may rapidly recognize alloantigens and activate the effector immune response, which leads to allograft rejection. However, the precise time-frame in which acute rejection is fundamentally triggered by preformed donor-specific memory T cells rather than by de novo activated naïve T cells is still to be established. Here, preformed donor-specific alloreactive T-cell responses were evaluated using the IFN-γ ELISPOT assay in a large consecutive cohort of kidney transplant patients (n = 90), to assess the main clinical variables associated with cellular sensitization and its predominant time-frame impact on allograft outcome, and was further validated in an independent new set of kidney transplant recipients (n = 67). We found that most highly T-cell sensitized patients were elderly patients with particularly poor HLA class-I matching, without any clinically recognizable sensitizing events. While one-year incidence of all types of biopsy-proven acute rejection did not differ between T-cell alloreactive and non-alloreactive patients, Receiver Operating Characteristic curve analysis indicated the first two months after transplantation as the highest risk time period for acute cellular rejection associated with baseline T-cell sensitization. This effect was particularly evident in young and highly alloreactive individuals that did not receive T-cell depletion immunosuppression. Multivariate analysis confirmed preformed T-cell sensitization as an independent predictor of early acute cellular rejection. In summary, monitoring anti-donor T-cell sensitization before transplantation may help to identify patients at increased risk of acute cellular rejection, particularly in the early phases after kidney transplantation, and thus guide decision-making regarding the use of induction therapy.     

A case of pheochromocytoma with renal artery stenosis and post-surgical watery diarrhea

A 35-year-old woman was admitted to our hospital with the following complaints, headache, sweating, anxiety, dizziness, nausea, vomiting and severe hypertension. The technical images (abdominal CT, scintigraphic octreotide scan and renal arteriography) revealed the presence of a left adrenal pheochromocytoma and stenosis of the renal artery. Ten days following adrenalectomy, watery diarrhea appeared. The long-acting somatostatin analogue octreotide (LAR, 30 mg/month, i.m.), was started, and after 2 weeks diarrhea decreased and gradually disappeared. In conclusion, we were confronted with an unusual case of pheochromocytoma associated with renal artery stenosis and the appearance of watery diarrhea some days after surgical treatment. Treatment with octreotide brought about the remission of diarrhea in this patient.     

Prognosis of Henoch-Sch?nlein nephritis in children.

All the survivors of a series of 88 patients with Henoch-Schönlein nephritis were examined after a follow-up of six and a half to 21 years (mean 9-9). Sixty-one patients had no demonstrable abnormality; six had minor urinary abnormalities; five had hypertension without urinary abnormally or renal dysfunction; four had heavy proteinuria; eight were in chronic renal failure, three of whom were on regular dialysis; and four patients had died within 25 months of onset. Neither corticosteroids nor immunosuppressive drugs alone or in combination appeared to influence the outcome. A clinical presentation with a combination of acute nephritis and a nephrotic syndrome and a high proportion of crescents in renal biopsy specimens was associated with a poor outcome. Neither the clinical presentation nor the renal morphology were, however, precise determinants of outcome. Outcome was not related to age, associated streptococcal infection, or recurrences of the rash. The clinical state two years after presentation was compared with the state six and a half years or more after presentation in 76 patients. The clinical state had changed in 32 patients, in 17 of whom it had deteriorated. It was not possible to identify with any certainty the patients who would deteriorate (or improve). Patients who have had Henoch-Schönlein nephritis should be followed up for at least five years.     

Infectious complications associated with renal transplantation: an analysis of risk factors.

To assess the multiple risk factors reported to be associated with onset of serious bacterial, fungal, viral, and protozoal infections in renal allograft recipients, a retrospective study of all renal transplantations performed at Yale-New Haven Medical Center from the inception of the transplantation program in December, 1967, to December, 1975, was undertaken. Ninety-six renal allograft transplants in 85 patients were available for evaluation during this study period. Renal allograft recipients were evaluated for incidence of infection from time of transplantation until transplant nephrectomy, death, or January 1, 1976. All infections were characterized by type of infection, organism, site, and time of onset post-transplantation. Recipients with infections were also evaluated for their donor type, living-related or cadaveric, age at time of transplantation, granulocytopenia, corticosteroid therapy, and rejection episodes. There were 215 infections, 92 of which were defined as serious, in 78 of the 96 renal allograft recipients. Eighteen renal allograft recipients had no infections. Granulocytopenia, but not rejection, correlated with serious infections at some time in the patient''s course. However, no significant temporal relationship between serious infections and episodes of granulocytopenia or rejection could be established. Mortality rate and incidence of serious infection was higher in the group receiving high dose corticosteroid therapy compared with the group receiving lower doses of corticosteroids. The mortality rate in these 85 transplant recipients was 33%. Seventy-four percent of these deaths were directly related to infection (24% of 85 patients).     

Digital vascular imaging and selective renin sampling in evaluation of vascular anatomy in renal transplant recipients.

Sixty-five renal transplant recipients underwent digital vascular imaging of the graft and simultaneous selective venous sampling for plasma renin activity. Renal artery stenosis was found in seven patients but did not appear to be functionally important. Diffuse intrarenal arterial attenuation was found in seven patients and was associated with impaired graft function and perfusion; it may indicate chronic rejection. Lower pole hypoperfusion was found in nine patients without impaired graft function or perfusion; its clinical relevance is uncertain. Aneurysmal dilatation of the main renal artery was found in two patients. Severe hypertension was common in patients with these three major abnormalities, but a causal association between the abnormality and hypertension could rarely be inferred. It may be the abnormalities on digital vascular imaging, especially diffuse intrarenal arterial attenuation and lower pole hypoperfusion, are secondary to severe hypertension. Digital vascular imaging with simultaneous selective venous sampling for plasma renin activity is useful in evaluating the vascular anatomy of the grafted kidney and in assessing any abnormality found. The combined procedure was well tolerated by all patients with no complications and no incidence of acute tubular dysfunction or proteinuria after the investigation.