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Biomedical subjects

A J Matas

Publications and source records attributed to A J Matas.

At least 37 records · Page 2Linked to original sources
PubMed2001

Donor scoring system for cadaveric renal transplantation.

We studied early renal function in 241 consecutive patients who received cadaveric renal transplants at two different transplantation centers (group 1, n = 90; group 2, n = 151). Univariate and multivariate analyses of data from group 1 showed a significant correlation between seven donor variables and early renal function after cadaveric renal transplantation. A scoring system was developed from these seven donor variables (cause of death, 0-6 points; history of hypertension, 0-6; final creatinine clearance before procurement, 0-6; age, 0-6; history of diabetes mellitus, 0-3; cold ischemia time, 0-3; and severity of renal artery plaque, 0-3). Data from group 2 were used to validate the donor scoring system and stratify cadaver kidneys on the basis of score: grade A, 0-5 points; grade B, 6-10; grade C, 11-15; and grade D, 16-32. A significant decline in early renal function was observed with increasing donor score and grade of cadaver kidney. In conclusion, a donor scoring system based on information available at the time of procurement can be used to estimate early graft function after cadaveric renal transplantation and may assist in the allocation of marginal organs.

Adolescent↗
PubMed2000

Pre-emptive transplants for patients with renal failure: an argument against waiting until dialysis.

BACKGROUND: Pre-emptive kidney transplants have not been favored in some centers because of concern about possible increased noncompliance and allegedly inferior long-term results. We analyzed our experience with pre-emptive kidney transplants to determine whether such concerns are justified. PATIENTS AND METHODS: Between January 1, 1984, and June 30, 1998, we performed 1849 adult primary kidney transplants: 385 pre-emptive (recipients not undergoing dialysis, ND) and 1464 non-pre-emptive (recipients undergoing dialysis, D). Results were subdivided by donor source: cadaver (CAD) and living donor (LD). ND recipients tended to be younger, but otherwise, the two groups were similar. Posttransplantation quality of life in recipients was evaluated using the nationally standardized Short Form Health Survey (SF-36). The posttransplantation employment status of the recipients was also evaluated. RESULTS: The patient survival rate 5 years posttransplantation was significantly better for ND (vs. D) recipients for both CAD (92.6% vs. 76.6%, P=0.001) and LD (93.3% vs. 89.5%, P=0.02) transplants. The 5-year patient survival rate was significantly higher for ND recipients compared with recipients undergoing dialysis for < 1, 1-2, and > 2 years pretransplantation for both CAD (P=0.0005) and LD (P=0.0001) transplants. The graft survival rate 5 years posttransplantation was similar between ND and D recipients for CAD transplants, but significantly better for ND (vs. D) recipients of LD transplants (92.3% vs. 84.8%, P=0.006). For CAD transplants, the 5-year graft survival rate was not different when ND recipients were compared with recipients undergoing dialysis for < 1, 1-2, and > 2 years pretransplantation; for LD transplants it was significantly higher for ND recipients compared with recipients undergoing dialysis for < 1, 1-2, and > 2 years pretransplantation (P=0.04). The incidence of acute and chronic rejection was no different between ND and D recipients for either CAD or LD transplants, and it was also not affected by the pretransplantation time undergoing dialysis. Graft loss secondary to the recipient's discontinuation of immunosuppressive therapy (a crude estimate of compliance) was similar between ND and D recipients. Five years posttransplantation, the SF-36 scores regarding the recipient's quality of life and the employment status were similar for ND compared with D recipients, regardless of donor source. CONCLUSIONS: ND recipients do not seem to have higher rates of noncompliance than D recipients. Results for ND recipients seem to be superior than for D recipients, supporting the contention that renal failure patients should, if possible, undergo transplantation before dialysis.

Actuarial Analysis↗
PubMed2000

Increased incidence of cardiac complications in kidney transplant recipients with cytomegalovirus disease.

BACKGROUND: The transplant literature has not shown cytomegalovirus (CMV) disease to be a significant risk factor for posttransplant cardiac complications. A large number of nontransplant studies have, however, reported an association between coronary heart disease (CHD) and CMV disease. Pathology studies have demonstrated a high incidence of CMV in atheromatous plaques from the coronary circulation. METHODS: We performed multivariate analysis to determine if posttransplant CMV disease was a significant risk factor for cardiac complications in kidney transplant recipients. We also performed univariate analysis to determine which cardiac complications were more common in the recipients with CMV disease. RESULTS: Between January 1, 1984 and June 30, 1997, 1859 adults underwent kidney transplants at our institution. Of these, 377 developed one of the following cardiac complications posttransplant: myocardial infarction, angina, arrhythmia, congestive heart failure, and angiographic vessel occlusion. By multivariate analysis, significant risk factors for one of the above cardiac complications were recipient age >50 years [odds ratio (OR)=2.5, P=0.0001], diabetes (OR=1.99, P=0.0001), a history of cardiac disease pretransplant (OR= 1.34, P=0.04), and CMV disease (OR=1.5, P=0.01). Univariate analysis demonstrated that recipients with CMV disease had a higher overall incidence of cardiac complications. Arrhythmias, congestive heart failure, and vessel occlusion were more common in those with CMV disease. The incidence of myocardial infarction, angina, and cardiac arrest did not differ between the two groups (recipients with versus without CMV disease). CONCLUSIONS: CMV disease is associated with an increased risk of cardiac complications in kidney transplant recipients. In our series, angiographic vessel occlusion was more common in recipients with CMV disease. This interesting finding may support the theory that CMV plays some role in the pathogenesis of CHD.

Adult↗
PubMed2000

Clinical determinants of multiple acute rejection episodes in kidney transplant recipients.

BACKGROUND: Recipients with multiple (more than one) acute rejection (AR) episodes have significantly lower graft survival rates than those with no AR or only one treated episode. However, fewer than 50% of recipients treated for one AR episode will have another episode. METHODS: We studied recipients with at least one AR episode to determine whether any clinical features could identify risk factors for multiple AR. RESULTS: Between January 1, 1984, and June 30, 1997, a total of 1793 recipients underwent a kidney transplant at our institution. Of these, 354 were treated for one AR episode, 307 for more than one. By multivariate analysis, recipients at highest risk for multiple AR episodes were those with initial delayed or slow graft function (relative risk=1.5, P=0.05), those with initially severe AR (as judged by vascular involvement or steroid resistance), and those with an initial early AR episode (<6 months posttransplant). The remaining variables tested were not significant. Graft survival in recipients with more than one AR episode was significantly lower than in those with only one AR episode. Graft survival at 5 years posttransplant was 52.5% in recipients with more than one AR episode and 85.1% in recipients with one AR episode (P=0.0001). Chronic rejection as a cause of graft loss was significantly more common in recipients with more than one vs. only one AR episode (34.8% vs. 8.9%, P=0.001). CONCLUSION: Clinical features may be used to identify recipients at higher risk for multiple AR episodes. These recipients can then be targeted with more aggressive or novel immunosuppressive regimens in an attempt to reduce the likelihood of another AR episode.

Acute Disease↗
PubMed2000

Living unrelated donors in kidney transplants: better long-term results than with non-HLA-identical living related donors?

BACKGROUND: Given the severe organ shortage and the documented superior results obtained with living (vs. cadaver) donor kidney transplants, we have adopted a very aggressive policy for the use of living donors. Currently, we make thorough attempts to locate a living related donor (LRD) or a living unrelated donor (LURD) before proceeding with a cadaver transplant. METHODS: We compared the results of our LURD versus LRD transplants to determine any significant difference in outcome. RESULTS: Between 1/1/84 and 6/30/98, we performed 711 adult kidney transplants with non-HLA-identical living donors. Of these, 595 procedures used LRDs and 116 used LURDs. Immunosuppression for both groups was cyclosporine-based, although LURD recipients received 5-7 days of induction therapy (antilymphocyte globulin or antithymocyte globulin), whereas LRD recipients did not. LURD recipients tended to be older, to have inferior HLA matching, and to have older donors than did the LRD recipients (all factors potentially associated with decreased graft survival). Short-term results, including initial graft function and incidence of acute rejection, were similar in the two groups. LURD recipients had a slightly higher incidence of cytomegalovirus disease (P=NS). We found no difference in patient and graft survival rates. However, the incidence of biopsy-proven chronic rejection was significantly lower among LURD recipients (16.7% for LRD recipients and 10.0% for LURD recipients at 5 years posttransplant; P=0.05). LRD recipients also had a greater incidence of late (>6 months posttransplant) acute rejection episodes than did the LURD recipients (8.6% vs. 2.6%, P=0.04). The exact reason for these findings is unknown. CONCLUSION: Although LURD recipients have poorer HLA matching and older donors, their patient and graft survival rates are equivalent to those of non-HLA-identical LRD recipients. The incidence of biopsy-proven chronic rejection is lower in LURD transplants. Given this finding and the superior results of living donor (vs. cadaver) transplants, a thorough search should be made for a living donor-LRD or LURD-before proceeding with a cadaver transplant.

Adult↗
PubMed2000

Immunologic and nonimmunologic factors: different risks for cadaver and living donor transplantation.

BACKGROUND: There is a debate about the relative contribution of immunologic (rejection) and nonimmunologic (limited nephron mass) factors in long-term graft survival. METHODS: Using multivariate analysis, we studied the association of the following variables with outcome: delayed graft function (DGF), acute rejection, recipient race (black vs. nonblack), donor age (<50 vs. > or =50), donor race, and donor and recipient gender. Because of the association between DGF and rejection, recipients were grouped as follows: DGF, rejection; DGF, no rejection; no DGF, rejection; no DGF, no rejection. Data were analyzed on 1199 first kidney transplants in adults (752 living donor, 447 cadaver donor) done between January 1, 1985 and December 31, 1996. Two analyses were done: first, all transplants; second, only those with > or =1 year survival. For both, there was no difference in risk factors if death with function was or was not censored. RESULTS: For all cadaver transplant recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50. For living donor recipients, only acute rejection was a risk factor. When only 1-year graft survivors were considered, risk factors were the same: for cadaver recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50; for living donor recipients the risk factor was rejection. CONCLUSION: We found immunologic factors (rejection with or without DGF) to be significant in both living donor and cadaver donor transplants. Nonim. munologic factors (donor age, recipient race) were significant only in cadaver donor transplants.

Acute Disease↗
PubMed2000

Iliac artery stenosis masquerading as diuretic resistant congestive heart failure.

Iliac artery stenosis is a rare cause of renal dysfunction in renal allograft recipients. Its presence can mimic renovascular hypertension and yet alter the very radiologic tests used to diagnose renal artery stenosis. We investigate a case of iliac artery stenosis that presented with diuretic resistant fluid overload, hypertension and limb claudication that exposed the pitfalls in the diagnosis and management of this condition. Successful stent placement, 8 months after transplant, resulted in return of the serum creatinine below the post-transplant nadir.

Aged↗
PubMed2000

Should I accept this kidney?

BACKGROUND: Transplant candidates frequently ask whether they should, based on information available at the time, accept a cadaver kidney or wait for a potentially better one. METHODS: We analyzed 937 first and second cadaver transplants done between January 1, 1984 and December 31, 1997 to determine if information available at the time an offer is made could be used to predict long-term graft survival. RESULTS: By Cox regression, risk factors for worse long-term graft survival were older donor age, cardiovascular or cerebrovascular cause of donor death, and delayed graft function (DGF). HLA-ABDR mismatch was marginally significant. Whether DGF will occur is not known at the time of an offer, but risk factors can be determined; we found these to be older donor age and > 10% panel-reactive antibodies (PRA) at transplantation (by Cox regression). Using these variables (PRA, ABDR mismatch, donor age, and donor cause of death) known at the time of an offer, we calculated the relative risk of worse long-term graft survival for each subgroup (Table 3 in manuscript). In general, older age and donor death from cardiovascular or cerebrovascular disease were associated with worse outcome. Kidneys from donors of < 50 yr had the best outcome, irrespective of match. CONCLUSION: The data provided can be used to help guide patients as to whether they are better off accepting an offered kidney or waiting for a potentially better one. If an offer is declined, the next kidney may have a potentially worse outcome.

Adolescent↗
PubMed2000

Renal transplantation for type II diabetic patients compared with type I diabetic patients and patients over 50 years old: a single-center experience.

INTRODUCTION: Transplantation of renal allografts for Type II diabetic patients has become increasingly common. Like Type I diabetics and patients over age 50, Type II diabetics are in a high-risk category for renal transplantation. Some investigators argue that the scarce resources of the valuable donor pool should not be allocated to these high-risk, older individuals with end-stage renal disease (ESRD) who often have significant comorbidity. We studied the outcome of renal transplantation for 90 Type II diabetics and compared it with the outcome for Type I diabetics and patients over age 50 with other primary diseases. METHODS: We conducted a retrospective review of data on all renal transplants performed at the University of Minnesota since September 1984 for Type II diabetics. We analyzed both patient and graft survival rates and compared them with the outcome for Type I diabetics and separately for all nondiabetics over age 50. We grouped recipients by donor source (living vs. cadaver) and age at transplant (< 50 vs. > 50). We studied reasons for graft loss, patient death, pre-operative morbidity, and post-operative complications. RESULTS: We found that recipient age and donor source did not affect outcome. Overall 5-yr patient survival for Type II diabetics was 61%; graft survival, 53%. Type II diabetics had significantly worse patient and graft survival than Type I diabetics and than nondiabetics over age 50. However, death-censored graft survival was not different between these groups, suggesting little difference in immunologic graft loss. CONCLUSIONS: Renal transplantation is a relatively safe, viable option for Type II diabetics with ESRD and significant comorbidity. Although their overall graft survival is less than for Type I diabetics and for nondiabetics over age 50, the immunologic graft failure rate is the same in all three groups.

Adult↗
PubMed2000

Predicting clinical outcome in the elderly renal transplant recipient.

BACKGROUND: The purpose of this study was to evaluate graft and patient survival in first-time kidney transplant recipients 60 years old or older, and to identify pretransplant risk factors that predict clinical outcome. METHODS: We reviewed the clinical course of 206 recipients, 60 years old or older, of first kidney transplants at the University of Minnesota. Patient and graft survival were compared with 1640 patients aged 18 to 59 transplanted during the same time period. Regression analysis was performed to identify risk factors that predicted a poor outcome. RESULTS: In patients 60 years old or older, graft survival at one and five years was 86 and 60%, and patient survival at one and five years was 90 and 68%, respectively. Graft and patient survival were decreased compared with recipients aged 18 to 59, but were similar when censored for patient death as a cause of graft loss. A pretransplant history of nonskin malignancy and vascular disease and a current smoking history were risk factors for decreased graft and patient survival. To determine the potential impact of screening for low-risk patients, we evaluated graft and patient survival in patients age > or =60 without these risk factors versus those with one or more risk factors. In the absence of risk factors, both graft and patient survival were significantly improved compared with patients with these risk factors and were equivalent to that of patients aged 18 to 59. CONCLUSIONS: Renal transplantation is a safe and effective therapy for the older renal failure patient. In the absence of identified risk factors, graft survival is equivalent to that seen in younger patients.

Adolescent↗