Biomedical subjects

Leroy R Thacker

Publications and source records attributed to Leroy R Thacker.

5 recordsLinked to original sources

PubMed2005

Vasodilatation vs. immunotherapy to prevent delayed graft function: delayed graft function as an indication of immune activation.

Delayed renal allograft function (DGF) is a factor for acute rejection and chronic allograft nephropathy. Cold ischemia time (CIT) is associated with an increased in DGF. Twenty patients receiving allografts with CIT>12 were enrolled in a double-blinded, randomized (1:1), placebo-controlled study to assess vasodilatation with fenoldopam (Abbott; dopamine-1 receptor agonist) on DGF. Fenoldopam infusion began at arterial anastomosis at 0.025 microg/kg/min and titrated to 0.1 microg/kg/min continued for 48 h postop (PO). Immunosuppression included steriods, MMF, and calcinurin inhibitors begun 36 h PO. Antibody induction (AI) using antithymocyte globulin (rabbit) (AT-G(r); Sangstat) was added halfway through the study to African-Americans and for PRA>40%. The need for dialysis, cumulative urine output (UOP), and creatinine (Cr) at PO day 7, 14, and 30 were compared. Eighteen patients completed the study drug infusion. Demographics of groups were not different. There was no difference between fenoldopam and controls for dialysis, UOP at 48 and 72 h, or Cr at 7, 14, or 30 days. There was a difference in UOP when AI (n=7) was compared to non-AI (n=11). At 48 h non-AI UOP 4796+/-3284 ml compared to AI UOP 8960+/-5130 ml (p=0.050). At 72 h, non-AI patients had UOP of 6824+/-4547 ml compared to AI patients with UOP of 12196+/-5868 ml (p=0.044). There was a trend to a lower Cr at day 7 for AI 2.7+/-2.1mg/dl compared to 4.9+/-3.0 mg/dl in non-AI (p=0.11). There was no difference in dialysis or Cr at day 14 and 30 between the AI and non-AI patients. AI with AT-G(r) significantly increases UOP in allografts with CIT>12 h, whereas vasodilatation did not. Therapy for DGF may include AT-G(r) AI.

Adult↗

PubMed2004

Sensitivity of expanded-criteria donor kidneys to cold ischaemia time.

UNLABELLED: The United Network for Organ Sharing (UNOS), working in conjunction with organ procurement organizations and transplant programmes, has recently defined a class of cadaver kidney grafts for special allocation procedures to enhance utilization of those organs. The criteria defining these expanded-criteria donor (ECD) kidneys are donor age > or = 60 yr or donor age between 50 and 59 yr plus two of the following characteristics: donor history of cerebrovascular accident (CVA), donor history of hypertension (htn), and elevated creatinine (>1.5) at any time during donor management. Kidney grafts from ECD donors carry an increased relative risk of non-function compared to other cadaver kidney grafts. The goal of the special allocation procedure is to reduce the time associated with placement by matching ECD grafts with patients previously designated as being willing to accept them. In assessing the potential impact of these allocation procedures, the sensitivity of ECD grafts to cold ischaemia time (CIT) became of great significance. Specifically, we questioned whether minimization of CIT might reduce the relative risk of poor graft function, justifying reduction of the geographical range of placement and thereby reducing the time the grafts would spend in-transit. METHODS: To assess this, we queried the SEOPF database for cadaveric kidney transplants between 1/1/1997 and 15/8/2002. There were 1312 transplants from ECD donors during this period and 8451 from non-ECD donors. Between these groups, there were no significant differences in recipient gender, ethnicity, peak and most recent panel reactive antibody (PRA). Recipients of ECD kidneys were significantly older: 50.9 +/- 13.0 yr vs. 44.9 +/- 13.9 (mean age +/- SD, P < 0.0001). There were statistically significant but very small differences in the degree of AB and DR mismatch between the groups. RESULTS: Defining delayed graft function (DGF) as dialysis within the first week post-transplant and primary non-function (PNF) as dialysis within the first week and failure in the first year, we found an association with CIT as illustrated in Table 1. Overall, ECD kidneys had a significantly increased (P < 0.0001) incidence of PNF and DGF. Notably, PNF in ECD appeared to be uniformly distributed across CIT and while DGF was CIT-dependent, the DGF differences between ECD and non-ECD were fairly consistent across CIT. CONCLUSION: While CIT minimization is potentially beneficial, ECD kidneys do not appear to be more sensitive to it than non-ECD kidneys.

Cryopreservation↗

PubMed2004

The Living Organ Donor Network: a model registry for living kidney donors.

The South-Eastern Organ Procurement Foundation presents the first report on a programme to track donors through questionnaires completed at the time of donation, 3 months, 6 months, and yearly thereafter. Donors at participating centres were eligible for an insurance policy with a total benefit of 250,000 US dollars, covering accidental death related to donation, surgery, medical expenses of complications, and disability income. The four participating centres have registered 104 donors. Response rate to the questionnaires was 90.91%. The majority of the donors come from the immediate family (81.62%), either by blood or marriage. The majority of donors are employed full time, with income ranges similar to the national census. Donors rely on employer-provided vacation time and sick leave to recuperate, but the average donor required 12 days of unpaid leave before returning to work. Donors also experienced costs of transportation, lodging, and childcare. Anti-depressants were prescribed to 10.58% of donors, and 4.8% of donors reported they are treated for hypertension. Complications were reported by 37.5% of the donors, but only 7.6% of the complications were serious enough to require hospitalization or surgery. Donors reported higher complication rates than reported by the centres and experience financial burdens afterwards.

Employment↗

PubMed2003

Human leukocyte antigens DR and AB and kidney retransplantation.

BACKGROUND: Although class II human leukocyte antigen (HLA) DR mismatching has been shown to demonstrate a significant effect on kidney regraft survival, it has not generally been clinically emphasized. METHODS: We examined 2,574 kidney retransplants performed in Southeastern Organ Procurement Foundation centers between January 1988 and December 1997 in which there was ABDR typing on both donor and recipient and pretransplant panel reactive antibody (PRA) data. RESULTS: Cox regression of multiple variables demonstrated that the most important risk factors in descending order were DR mismatching, non-white recipient, female donor, PRA as a continuous variable, and cold ischemia time. Although DR mismatching demonstrated a significant effect in white recipients, the impact was much greater in non-white recipients. In both groups, zero to four AB mismatches demonstrated no significant effect on regraft survival if DR was matched and only a minimal effect when DR was mismatched. The discrepancy of these findings with reports that demonstrate a stepwise decrease in regraft survival on the basis of the total zero to six ABDR mismatches was explained by the fact that the zero to six ABDR mismatches are a combination of AB mismatches with little effect and DR mismatches with a major effect. Regraft survival decreased progressively in association with increasing PRA. CONCLUSIONS: DR matching is critically important in kidney retransplantation. There was no significant difference in survival of zero ABDR mismatched retransplants compared with one to four AB and zero DR mismatched retransplants. On the other hand, kidney graft survival of all one to four AB and zero DR mismatches exceeded that of one or two DR mismatched retransplants. We propose that the association of decreasing regraft survival with increasing PRA reflects undetected sensitization to class II, and possibly class I, antigens.

Female↗

PubMed2002

Sensitized patients require sharing of highly matched kidneys.

BACKGROUND: Improved HLA matching can allow for renal transplantation in sensitized patients. United Network for Organ Sharing (UNOS) is currently considering removing the points awarded for HLA matching. METHOD: Twenty-six transplant centers shared kidneys, according to the algorithm: A, UNOS mandatory 0-mismatch (MM) share; B, UNOS mandatory 0-mm payback; C, 0 - B,Dr-MM; PRA> or = 40%; ROP tray negative; D, 0-B,Dr-MM; panel reactive antibodies (PRA) <40%; E, 0-B,Dr payback; F, local use. RESULTS: A total of 354 patients received transplants through the program and were compared with 6492 control patients. There was a significantly greater primary nonfunction rate in sensitized patients in spite of similar length cold ischemia time. Blacks were not significantly disadvantaged by the HLA matching requirements of the program. White recipients were favored by the matching program to the detriment of race group "other." Women were more frequently found in the sensitized groups but were not favored by sharing. Retransplant patients and patients with current PRA > or = 40% were favored by the sharing program. Sharing for HLA match does not improve graft survival at 1, 2, 3 years. CONCLUSIONS: (1). Elimination of suboptimal HLA matching by UNOS will probably not adversely affect 1-, 2-, and 3-year graft survival; (2). Removing the consideration for HLA matching will result in fewer transplant opportunities for highly sensitized patients such as retransplants and currently sensitized patients.

Adult↗