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Stephen C Textor

Publications and source records attributed to Stephen C Textor.

34 records · Page 2Linked to original sources
PubMed2004

Histologic findings of antibody-mediated rejection in ABO blood-group-incompatible living-donor kidney transplantation.

The purpose of this study was to characterize the histology of antibody-mediated rejection (AMR) in ABO blood-group-incompatible (ABOI) kidney transplants as well as on protocol biopsies performed at the time of stable allograft function. Between 5/99 and 1/02, we performed 32 ABOI kidney transplants (13 A2, 19 non-A2 blood-group living donors). Nineteen biopsies were performed for allograft dysfunction, and 127 protocol biopsies were performed 0, 3, 7, 14, 28 days and 3 and 12 months post transplant. Twenty-five of 32 patients have functioning allografts (mean 585 days post transplant). Nine of 32 (28%) developed clinical AMR. Biopsy revealed glomerular thrombi (78%), mesangiolysis (78%), peritubular capillary C4d staining (56%) and neutrophil infiltration (67%), interstitial hemorrhage and necrosis (56%) and arteriolar thrombi (33%). Subclinical AMR was diagnosed by protocol biopsies in four patients. Findings consisted of glomerular thrombi (100%), mesangiolysis (25%), and C4d staining (100%). In late protocol biopsies performed 214-420 days post transplant, mild mesangiolysis was seen in 2/17 (11.7%), and C4d immunostaining was detected in 3/12 (25%). AMR is characterized by glomerular thrombi, mesangiolysis, peritubular capillary neutrophil infiltration interstitial hemorrhage, necrosis, and C4d deposition. Glomerular thrombi appear early in AMR and may appear prior to graft dysfunction.

ABO Blood-Group System↗
PubMed2004

Hypertension.

Explore the source record for details and available documents.

Antihypertensive Agents↗
PubMed2004

Ischemic nephropathy: where are we now?

Identification and reversing the loss of kidney function beyond occlusive disease of the renal arteries poses a major clinical challenge. Recent studies indicate that atherosclerotic renal artery stenosis develops as a function of age and is commonly associated with other microvascular disease, including nephrosclerosis and diabetic nephropathy. The risks of renal artery stenosis are related both to declining kidney function and to accelerated cardiovascular disease, with increased morbidity and mortality. Newer drugs, including agents that block the renin-angiotensin system, have improved the level of BP control for renovascular hypertension. Progressive renovascular disease during medical therapy can produce refractory hypertension, congestive heart failure, and renal failure with tubulointerstitial fibrosis. Recent studies indicate a complex interplay of oxidative stress, endothelial dysfunction, and activation of fibrogenic cytokines as a result of experimental atherosclerosis and renal hypoperfusion. Advances in imaging and interventional devices offer major new opportunities to prevent progressive loss of kidney function. Recent series indicate that although 25 to 30% of patients with impaired renal function can recover glomerular filtration after revascularization, many have no apparent change in kidney function and 19 to 25% experience a significant loss of kidney function, in some cases as a result of atheroemboli. To select patients who are most likely to benefit from vascular intervention, clinicians should understand the pathophysiology of developing ischemic nephropathy and the potential hazards of revascularization in the setting of diffuse atherosclerotic disease. Further research should be directed toward identification of critical disease, regulation of fibrogenesis, and the interaction with other atherosclerotic processes.

Humans↗
PubMed2004

Patient and graft outcomes from older living kidney donors are similar to those from younger donors despite lower GFR.

BACKGROUND: Donor age adversely affects deceased-donor kidney transplant outcomes, but its influence on living-donor transplantation is less well characterized. METHODS: Living-donor kidney transplants at a single center between 1998 and 2000 were reviewed. Data were abstracted for 52 transplants from donors aged > or =50 years and for a matched group of 104 transplants from donors aged <50 years. Survival indices were compared during the first three years' post-transplantation. Functional indices, including serial iothalamate clearances, were compared at 1, 12, and 24 months. RESULTS: Predonation glomerular filtration rate (GFR) was lower among older donors (94 +/- 12 vs. 108 +/- 17 mL/min/SA) but post-transplant compensatory hypertrophy was similar (11.7 +/- 26.3% vs. 7.7 +/- 31.4%). Recipients of older-donor grafts were older (52.8 +/- 16.5 vs. 46.1 +/- 15.1 years) and more frequently unrelated to the donor (54% vs. 39%). Trends toward higher frequency of slow graft function, cytomegalovirus (CMV) infection, and polyomavirus nephropathy were observed for older-donor grafts. Three-year recipient, graft, and death-censored graft survivals were > or =90% for both groups. At 1, 12, and 24 months, serum creatinine was higher and GFR was lower among recipients of older- compared with younger-donor grafts. Other functional indices (urine total protein, serum potassium and uric acid, hemoglobin, and number of antihypertensives) were not different. Donor age correlated with graft GFR at 1, 12, and 24 months for the entire study cohort by linear regression. CONCLUSION: Older donor age does not preclude excellent results from living-donor kidney transplantation but should be appreciated as being associated with relatively lower GFR.

Adolescent↗
PubMed2003

Revisiting the role of nephrectomy for advanced renovascular disease.

BACKGROUND: Despite the advances in antihypertensive therapy and renal revascularization, there remains a group of patients in whom renovascular disease leads to renal atrophy and treatment-resistant hypertension. METHODS: We performed an observational cohort study in which we reviewed blood pressures, renal function, and predictors of response in 74 patients who underwent nephrectomy of a small kidney for uncontrolled hypertension between 1990 and 2000. RESULTS: The median age of the patients was 65 years; 43 (58%) were women. Thirty-five patients (47%) underwent nephrectomy as part of combined revascularization of the contralateral kidney. Associated atherosclerotic diseases were common (28% to 49%), as were prior renal revascularization (21 [28%]) and hypertensive urgency/emergencies (23 [31%]). The mean (+/- SD) long axis of the affected kidney was 8 +/- 2 cm, and the mean function of the kidney (based on radioisotope renography) was 12% +/- 11% of total renal function. The average systolic blood pressure fell from 168 +/- 19 mm Hg to 136 +/- 18 mm Hg (P <0.0001) and diastolic blood pressure declined from 88 +/- 10 mm Hg to 76 +/- 9 mm Hg (P <0.0001) at the most recent available clinic visit (mean follow-up, 4.1 +/- 2.6 years). In addition, the number of antihypertensive medications decreased from 3.2 +/- 1.1 to 2.2 +/- 1.5 (P <0.0001). Renal function remained stable. Results were similar (preoperative blood pressure of 165/88 mm Hg taking three medications to 137/77 mm Hg taking two medications) among the 39 patients who had a nephrectomy without contralateral revascularization. CONCLUSION: Our results suggest that in selected patients with resistant hypertension and renal artery disease that has resulted in atrophic kidneys with reduced function, nephrectomy can improve blood pressure control without further loss in overall renal function.

Aged↗
PubMed2003

Mechanisms of renal structural alterations in combined hypercholesterolemia and renal artery stenosis.

OBJECTIVE: Atherosclerotic renovascular disease (ARVD) aggravates renal scarring more than other causes of renal artery stenosis (RAS), but the underlying pathogenic mechanisms of this potential profibrotic effect remain unclear. We tested the hypothesis that coexistence of atherosclerosis and RAS interferes with renal tissue remodeling. METHODS AND RESULTS: Single-kidney hemodynamics and function were quantified in vivo with electron-beam computed tomography in 3 groups of pigs (n=7 each): normal pigs, pigs 12 weeks after induction of unilateral RAS (RAS group), and pigs with similar-degree RAS fed a 12-week 2% hypercholesterolemic diet (HC+RAS, simulating early ARVD). Kidneys were studied ex vivo by Western blotting and immunohistochemistry. Renal volume, renal blood flow, and glomerular filtration rate were similarly decreased in RAS and HC+RAS ischemic kidneys, accompanied by similar increased expression of profibrotic factors like transforming growth factor-beta, tissue inhibitor of metalloproteinase-1, and plasminogen activator inhibitor-1. Nevertheless, HC+RAS kidneys showed increased intrarenal fibrosis compared with RAS-only kidneys. Furthermore, expression of nuclear factor-kappaB was increased, expression of extracellular (matrix metalloproteinase-2) and intracellular (ubiquitin) protein degradation systems was decreased, and apoptosis was blunted. CONCLUSIONS: Diet-induced HC superimposed on RAS accelerates the development of fibrosis in the stenotic kidney by amplifying profibrotic mechanisms and disrupting tissue remodeling. These alterations might contribute to renal disease progression in ARVD and might account for the increased propensity for end-stage renal disease.

Animals↗
PubMed2003

Overcoming a positive crossmatch in living-donor kidney transplantation.

Many patients who have an otherwise acceptable living-kidney donor do not undergo transplantation because of the presence of antibodies against the donor cells resulting in a positive crossmatch. In the current study, 14 patients with a positive cytotoxic crossmatch (titer </= 1 : 16) against their living donor underwent a regimen including pretransplant plasmapheresis, intravenous immunoglobulin, rituximab and splenectomy. Eleven of 14 grafts (79%) are functioning well 30-600 days after transplantation. Two grafts were lost to accelerated vasculopathy and one was lost to death with good function. No hyperacute or cellular rejections occurred. Antibody-mediated rejection occurred in six patients [two clinical (14%) and four subclinical (29%)] and was reversible with plasmapheresis and steroids. Our results suggest that selected crossmatch-positive patients can be transplanted successfully with living-donor kidney allografts, using a protocol of pretransplant plasmapheresis, intravenous immunoglobulin, rituximab and splenectomy. Longer follow-up will be needed, but the absence of anti-donor antibody and good early outcomes are encouraging.

Adult↗
PubMed2003

Managing renal arterial disease and hypertension.

Treating patients with renovascular disease is complex, particularly as imaging and medical techniques become more effective. Atherosclerotic renal artery disease is present in 7% of the general population above age 65 and in 20 to 45% of patients with coronary disease or aortoiliac disease. Most patients are treated medically, but when progressive hypertension, renal insufficiency, or circulatory congestion develops, revascularization should be considered. Endovascular procedures with arterial stents are now widely employed. These procedures sometimes offer major benefits in blood pressure control and stabilization of renal function. Stent procedures continue to entail hazards, including atheroemboli, arterial dissections, and thrombosis, in addition to restenosis rates of 14 to 20%. Small, randomized trials to date demonstrate no survival benefit to either endovascular or surgical revascularization as compared with medical management. Recognizing renal artery disease and directing revascularization procedures to those with the most benefit remains a premier challenge for the clinician.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2003

Blood pressure evaluation among older living kidney donors.

With more patients reaching end-stage renal disease, the demand for living kidney donation is increasing rapidly. Many potential donors are now in older age groups. The effects of increasing BP with age and the measurement criteria for hypertension in this group are not well defined. A total of 238 potential donors between 18 and 72 yr of age were prospectively studied, with a comparison of "clinic" BP values measured in the outpatient clinic with an oscillometric recorder (Dinamap; Critikon), ambulatory BP monitoring (ABPM) findings, and standardized BP values determined by nurses using American Heart Association criteria. Renal function was evaluated on the basis of iothalamate clearance (GFR) and urinary protein and microalbumin excretion. Ninety-six percent of subjects were Caucasian. All subjects exhibited normal GFR and urinary protein excretion. Three age groups were defined (group I, </=35 yr, n = 64; group II, 36 to 49 yr, n = 109; group III, >/= 50 yr, n = 65). BP increased with age, as determined with all methods. Subjects >/= 50 yr of age exhibited the highest clinic readings (145 +/- 2/83 +/- 1 mmHg, compared with 129 +/- 2/76 +/- 1 mmHg for group I, P < 0.01). Awake ABPM and nurse-determined BP measurements were lower than clinic readings, including those for group III (131 +/- 2/80 +/- 1 mmHg, compared with 145 +/- 2/83 +/- 1 mmHg in the clinic, P < 0.001). With the use of systolic BP values of >140 mmHg and/or diastolic BP values of >90 mmHg, 36.7% of subjects were initially considered hypertensive; this proportion decreased to 11% overall with awake ABPM findings (>135/85 mmHg). Measurement variability (SD in ABPM) and the effects of misclassification were greatest for donors >/= 50 yr of age. Multivariate regression indicated that GFR of both donors and recipients decreased with age, but regression identified no independent effect of BP. Recipient outcomes for up to 2 yr were equally good for donor kidneys considered normotensive or hypertensive on the basis of clinic BP measurements. These data indicate that higher arterial BP with age can lead to misclassification of many older living kidney donors. Sixty-two subjects with excellent kidney function were misclassified as hypertensive with clinic oscillometric measurements alone. Detailed evaluations of ABPM findings, GFR, and urinary protein levels are warranted for Caucasian subjects with high clinic BP readings who are otherwise suitable potential donors.

Adolescent↗
PubMed2002

Incidence and prognostic importance of acute renal failure after percutaneous coronary intervention.

BACKGROUND: In patients undergoing percutaneous coronary intervention (PCI) in the modern era, the incidence and prognostic implications of acute renal failure (ARF) are unknown. METHODS AND RESULTS: With a retrospective analysis of the Mayo Clinic PCI registry, we determined the incidence of, risk factors for, and prognostic implications of ARF (defined as an increase in serum creatinine [Cr] >0.5 mg/dL from baseline) after PCI. Of 7586 patients, 254 (3.3%) experienced ARF. Among patients with baseline Cr <2.0, the risk of ARF was higher among diabetic than nondiabetic patients, whereas among those with a baseline Cr >2.0, all had a significant risk of ARF. In multivariate analysis, ARF was associated with baseline serum Cr, acute myocardial infarction, shock, and volume of contrast medium administered. Twenty-two percent of patients with ARF died during the index hospitalization compared with only 1.4% of patients without ARF (P<0.0001). After adjustment, ARF remained strongly associated with death. Among hospital survivors with ARF, 1- and 5-year estimated mortality rates were 12.1% and 44.6%, respectively, much greater than the 3.7% and 14.5% mortality rates in patients without ARF (P<0.0001). CONCLUSIONS: The overall incidence of ARF after PCI is low. Diabetic patients with baseline Cr values <2.0 mg/dL are at higher risk than nondiabetic patients, whereas all patients with a serum Cr >2.0 are at high risk for ARF. ARF was highly correlated with death during the index hospitalization and after dismissal.

Acute Kidney Injury↗
PubMed2002

Resistant hypertension: comparing hemodynamic management to specialist care.

Although resistant hypertension affects a minority of all hypertensives, this group continues to experience disproportionately high cardiovascular event rates despite newer antihypertensive agents. Hypertension represents an imbalance of hemodynamic forces within the circulation, usually characterized by elevated systemic vascular resistance. We studied the utility of serial hemodynamic parameters in the selection and titration of antihypertensive medication in resistant hypertensive patients using highly reproducible noninvasive measurements by thoracic bioimpedance. Resistant hypertension patients (n=104) were randomized to drug selection based either on serial hemodynamic (HD) measurements and a predefined algorithm or on drug selection directed by a hypertension specialist (SC) in a 3-month intensive treatment program. Blood pressure was lowered by intensified drug therapy in both treatment groups (169+/-3/87+/-2 to 139+/-2/72+/-1 mm Hg HD versus 173+/-3/91+/-2 to 147+/-2/79+/-1 mm Hg SC, P<0.01 for systolic and diastolic BP), using similar numbers and intensity of antihypertensive medications. Blood pressures were reduced further for those treated according to hemodynamic measurements, resulting in improved control rates (56% HD versus 33% SC controlled to </=140/90 mm Hg, P<0.05) and incremental reduction in systemic vascular resistance measurements. Although the number of patients taking diuretics did not differ between groups, final diuretic dosage was higher in the hemodynamic cohort. Our results demonstrate superior blood pressure control using a treatment algorithm and serial hemodynamic measurements compared with clinical judgment alone in a randomized prospective study. Our measurements of thoracic fluid volume support occult volume expansion as a mediator of antihypertensive drug resistance and use of impedance measurements to guide advancing diuretic dose and adjustment of multidrug antihypertensive treatment.

Adrenergic beta-Antagonists↗
PubMed2002

Incidental renal artery stenosis among a prospective cohort of hypertensive patients undergoing coronary angiography.

OBJECTIVE: To determine the feasibility, safety, and clinical yield of angiographic screening among hypertensive patients undergoing coronary angiography. PATIENTS AND METHODS: This study was a prospective cohort analysis of hypertensive patients who underwent cardiac catheterization at a tertiary care referral center from July 1998 to March 1999. Abdominal aortography was performed to screen for renal artery stenosis, the percentage of which was measured. RESULTS: The mean +/- SD age of the 297 study patients was 64.9+/-10.2 years; 58.6% were male, and 98.0% were white. Mean +/- SD systolic/diastolic blood pressure was 142.8+/-22.5/79.6+/-11.4 mm Hg. Aortography required a mean incremental dose of 62+/-9 mL of nonionic contrast agent. No complications were attributable to aortography. Of 680 renal arteries, 611 (90%) were visualized adequately. Also, 53% of patients had normal renal arteries, 28% had stenoses less than 50%, and 19.2% had stenoses of 50% or more. Renal artery stenosis was bilateral in 3.7% of patients and high grade (>70% stenosis) in 7%. Patients with renal artery stenosis were more likely to have had a previous coronary intervention. In multivariate analysis, systolic blood pressure (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.03-138; P=.02), history of stroke or transient ischemic attack (OR, 2.7; 95% CI, 1.27-5.78; P=.01), and cancer (OR, 2.0; 95% CI, 1.02-3.82; P=.04) independently correlated with renal artery stenosis of 50% or more. CONCLUSION: The prevalence of incidental renal artery stenosis among hypertensive patients undergoing coronary catheterization is significant. Therefore, screening abdominal aortography should be considered in these patients to better define their risk of cardiovascular complications.

Aortography↗