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Biomedical subjects

M R First

Publications and source records attributed to M R First.

At least 145 records · Page 8Linked to original sources
PubMed1991

Efficacy of induction therapy in cadaveric renal transplantation comparing rabbit antithymocyte serum and Minnesota antilymphoblast globulin.

From August 1986 to July 1989, 98 patients receiving primary cadaveric kidney transplants received either RATS (n = 50) or MALG (n = 48) during the induction phase of a quadruple immunosuppressive protocol. Patient groups were well matched. The duration of RATS and MALG treatment and the time of CyA induction were equivalent. Serum creatinine and rejection episodes up to 1 year were not statistically different. Hematologic side effects resulted in dose reduction of MALG in 42% of patients without adverse rejection results. In the RATS group, no dosage reductions were required. One-year patient survivals (96% to 100%), and 1-year graft survival (82% to 85%) were not significantly different in the 2 groups. Infectious complications were 30% higher in the MALG group and a significant factor in 2 deaths. Monitoring of lymphocyte subsets revealed insignificant differences in the percent of decrease of each cell population between MALG and RATS groups during induction.

Adult↗
PubMed1990

Failure of orthoclone OKT3 retreatment in a pancreas transplant recipient with antimurine antibodies.

Orthoclone OKT3 is a murine monoclonal antibody that blocks the generation and function of T lymphocytes. It has been shown to be effective in reversing acute cellular rejection in solid organ transplants. However, potential development of antimurine antibodies restricts the duration that the drug can be used and the ability to reuse the drug. The case reported in this article illustrates the failure of retreatment with OKT3 when high titer (1:3200) antimurine antibodies are present. Lack of efficacy of the drug was documented by virtually undetectable circulating OKT3 levels in plasma, no decrease in T3 lymphocytes, and organ rejection. OKT3 should only be reused when immune monitoring (antimurine antibody status, lymphocyte subsets, and OKT3 plasma levels) is performed before, during, and after its use. Patients with high-titer anti-OKT3 antibody should not be retreated with OKT3.

Adult↗
PubMed1990

Antimurine antibody formation following OKT3 therapy.

OKT3 is an IgG2a murine monoclonal antibody directed against the CD3 antigen receptor of human T lymphocytes. A major concern with OKT3 treatment in solid organ transplant recipients is the development of antimouse antibody, which may preclude retreatment with this agent. We have administered OKT3 on 215 occasions (150 renal, 34 hepatic, 26 cardiac, 5 pancreatic) in 179 patients between April 1982 and December 1988. The mean duration of treatment was 10.5 days (range, 2-22 days). Antimouse antibody data were analyzed on the most recent 133 treatment courses where the antibody status was available pretreatment. Determination of antimouse antibody production was elicited by ELISA technology at days 0, 7, 14, and 28 of OKT3 treatment. Patients were categorized according to the antibody response as follows: (a) absence of antibody; (b) low titer (1:100); or (c) high titer (greater than or equal to 1:1000). Our earlier experience has demonstrated that retreatment with OKT3 is successful in groups a and b. The development of antimurine antibodies was analyzed with regard to the following parameters: (1) The duration of OKT3 treatment; (2) treatment type (prophylactic, primary, or secondary); (3) primary treatment or retreatment; (4) concomitant immunosuppressive regimen (double or triple therapy); (5) dosage of concomitant immunosuppressive drugs; and (6) transplant organ type. The following results were obtained. (1) Duration of treatment had no effect on antibody production (11.0 days in antibody negative and 10.0 days in antibody positive). (2) There was no difference in antibody formation rates for the first treatment of OKT3 when it was used as prophylaxis (26%), primary (19%), or secondary (27%) therapy. (3) Antibody formation rate with first treatment was 29%; with retreatment, patients who were antibody negative following first treatment became positive in 28% of cases, and retreated patients who were low titer positive following first treatment converted to high titer in 57% of cases. (4) Antibody formation was higher in patients receiving double immunosuppressive therapy (36%) than in those receiving triple immunosuppressive therapy (21%) during OKT3 treatment. (5) Concomitant immunosuppression was lower in the antibody-positive group during OKT3 therapy: steroids, 61 mg/day vs. 52 mg/day; azathioprine, 89 mg/day vs. 66 mg/day; CsA, 317 mg/day vs. 186 mg/day. (6) Antibody formation rates were lower in non-renal transplants following first treatment with OKT3 (liver 17%, heart 17%, kidney 28%); this reflects the higher doses of concomitant immunosuppressive therapy used in nonrenal transplants.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Posttransplant anti-glomerular basement membrane nephritis in related males with Alport syndrome.

This report describes the development of anti-glomerular basement membrane (GBM) glomerulonephritis after kidney transplantation in related males with Alport syndrome. Antibodies in sera from one of these patients stained normal GBM, Bowman's capsule, tubular basement membranes, and epidermal basement membranes but did not stain tissues from an unrelated Alport male. The target antigen was found to be a 26 kd peptide of the noncollagenous domain of basement membrane collagen. This study provides further evidence of the importance of abnormalities of basement membrane collagen in the pathogenesis of the Alport nephropathy. We speculate that certain mutations at the Alport locus, such as large intragenic deletions or frame-shift mutations, may be associated with failure to develop immune tolerance to epitopes on this 26kd peptide. In the setting of permissive immune response and regulation, transplantation of a normal kidney may result in the generation of anti-GBM antibodies.

Basement Membrane↗
PubMed1989

Concomitant administration of cyclosporin and ketoconazole in renal transplant recipients.

18 renal transplant recipients receiving cyclosporin, prednisone, and azathioprine were given ketoconazole, a potent inhibitor of the cytochrome P-450 enzyme system. Within a month ketoconazole-induced blockade of cyclosporin metabolism allowed a significant reduction (451 vs 106 mg/day; 77%) of the mean dose of cyclosporin without altering cyclosporin whole blood trough levels, although maximum blood levels were almost halved. This dose reduction was maintained in patients followed up for up to 13 months. Renal and hepatic function were unchanged after the addition of ketoconazole. This drug interaction has the potential to reduce dramatically expenditure on cyclosporin in transplant recipients.

Administration, Oral↗
PubMed1989

Successful retreatment of allograft rejection with OKT3.

OKT3 is a murine monoclonal antibody to the CD3 antigen of human T lymphocytes. The production of human antimurine antibodies after treatment with OKT3 has been perceived as a major limitation to its extended use and reuse. Treatment of 142 patients with 168 courses of OKT3 resulted in the development of antimouse antibody in 28% of the patients. Twenty-six patients (16 kidney, 6 liver, 3 heart, 1 pancreas) have been retreated with 27 courses of OKT3. Eighteen patients had no antimurine antibodies present, and the rejection reversal rate was 83% (15/18). Six patients had a low-titer antimurine antibody present, and rejection reversal occurred in 5 (83%). Rejection was not reversed in 2 patients with a high-titer antibody. Development of antimurine antibody was more frequent in renal transplant recipients (33%) than in hepatic (12%) or cardiac transplant recipients (18%). We believe that this reflects the fact that concomitant immunosuppressive therapy is more likely to be reduced during OKT3 therapy in renal transplant recipients than in hepatic or cardiac transplant recipients. Retreatment of patients with no anti-OKT3 antibody resulted in depletion of CD3+ cells from the peripheral blood, but it took longer than in patients being treated with OKT3 for the first time. Similarly, serum OKT3 levels rose more slowly in retreated patients compared to first treatment. In retreating patients with a low-titer antimurine antibody, it often was necessary to increase the dose of OKT3 in order to achieve adequate serum OKT3 levels and to deplete CD3+ cells. De novo antimurine antibody developed in 4 of the 18 (22%) antibody-negative patients who were retreated. In conclusion, retreatment with OKT3 should not be considered unless the antibody status of the patient is known. Development of low-titer antibodies does not preclude successful retreatment with OKT3; however, alternate antirejection therapy should be used in patients with high-titer antimurine responses.

Antibodies, Anti-Idiotypic↗
PubMed1989

A comparison of the clinical utility of the radioimmunoassay, high-performance liquid chromatography, and TDx cyclosporine assays in outpatient renal transplant recipients.

Rapid and precise cyclosporine measurements are necessary to maximize immunosuppression and minimize toxicity. The new cyclosporine and metabolites TDx fluorescent polarization immunoassay was studied to determine its precision, sensitivity, and stability. Further, it was compared with the existing radioimmunoassay and high-performance liquid chromatography assays for clinical utility. The TDx procedure utilizes 50 microliter of serum or blood. The range of the assay is 0-1000 ng/ml for serum and 0-2000 ng/ml for whole blood. Precision studies of three control levels provided coefficients of variation of 2.1-5.8% for both assays. The sensitivities of the assays were less than 25 ng/ml for serum and less than 50 ng/ml for whole blood. In order to compare the TDx with the currently used RIA and HPLC methods, 362 simultaneous whole blood and serum samples were obtained from 122 renal transplant recipients over a 4-month period. The serum and whole blood TDx assays excluded fewer patients than either the RIA or HPLC assays with regard to sensitivity. The mean serum cyclosporine concentration for samples above the sensitivity was as follows: TDx 120 +/- 5 ng/ml, RIA 116 +/- 4 ng/ml, and HPLC 100 +/- 5 ng/ml. The mean whole-blood cyclosporine concentration for samples above the sensitivity was as follows: TDx 585 +/- 19 ng/ml, RIA 543 +/- 14 ng/ml, and HPLC 178 +/- 5 ng/ml. Serum and blood TDx levels correlated well with RIA levels, with regression coefficients of r = 0.813 and r = 0.897, respectively. Serum and blood TDx levels did not correlate strongly with HPLC levels, with regression coefficients of 0.332 and 0.781, respectively. Seventeen patients were diagnosed as having acute cyclosporine nephrotoxicity. The serum and whole-blood cyclosporine concentrations in these patients were at the upper end of the therapeutic range for all analytical methods. Five patients had acute cellular rejection; serum and whole-blood cyclosporine levels in these patients did not differ significantly from the stable patients when measured by each of the analytical methods. In conclusion, the TDx cyclosporine and metabolites assay provides reliable blood and serum concentrations that correlate well with RIA measurements in renal transplant recipients. This assay offers rapid sample turn-around times making possible same-day results for all patients without putting great demands upon the laboratory.

Ambulatory Care↗
PubMed1989

Prophylactic use of OKT3 in immunologic high-risk cadaver renal transplant recipients.

Prophylactic OKT3 was administered to 27 immunologic high-risk cadaver renal transplant recipients (multiple transplant and/or panel reactive antibody greater than 50%) as part of a sequential immunosuppressive protocol consisting of OKT3, prednisone, azathioprine, and cyclosporine. The first dose of OKT3 was administered intraoperatively. Patient survival was 100% with a mean follow-up period of 13 months. Graft survival at 1 year was 70% (19 of 27). Eight grafts were lost during the first 6 weeks. Causes of graft loss were hyperacute rejection or primary nonfunction (4), irreversible rejection (2), and technical (2). After the first month, single rejection episodes occurred in four patients and multiple rejection episodes in three patients; all were successfully reversed, and no further graft losses were encountered. Mean serum creatinine level at 1 month posttransplant was 141 mumol/L (1.6 mg/dL), and the average serum creatinine has remained at that level during the follow-up period. No serious infections were encountered. Prophylactic OKT3 administration resulted in depletion of CD3+ lymphocytes from the peripheral circulation throughout therapy, as well as the development of therapeutic serum OKT3 levels. Five of the 27 (22%) patients developed antimurine antibodies during or after OKT3 therapy; four of these patients had low-titer antimurine antibody, and one had high-titer antimurine antibody. First-dose reactions were generally mild in this group of patients. Prophylactic use of OKT3 in this patient population resulted in superior graft survival when compared with a similar group of patients not receiving OKT3.

Adult↗