An assessment of the Matrix 96 Direct Beta Counter for cytotoxic T lymphocyte precursor frequency analysis in human cardiac transplant recipients

McKenzie, David Charles Lennox (1999) An assessment of the Matrix 96 Direct Beta Counter for cytotoxic T lymphocyte precursor frequency analysis in human cardiac transplant recipients. MSc(R) thesis, University of Glasgow.

Abstract

This study was undertaken to assess the Matrix 96 Direct Beta Counter for the measurement of 51Chromium (51Cr)-release from cytotoxic T lymphocyte precursor (CTLp) frequency assays of human cardiac transplant recipients. The Matrix 96 was compared with a gamma counter for the measurement of maximal 51Cr-release from graded numbers of labelled target cells. Repeated counts by both counters were consistent. Variation between the Matrix 96 and the gamma counter was similar to the variation between repeated counts using the gamma counter, indicating that the counters were comparable for the measurement of 51Cr. The contribution of natural killer-like activity to target cell killing in the CTLp assay was investigated by the use of the K562 cell line in cold target competition assays. Ten responder-stimulator combinations were tested in the CTLp assay for cross-reactivity between K562 and allogeneic targets. Cytotoxicity was reduced in only one assay, suggesting that the cells which mediated lysis of allogeneic lymphocytes and K562 cells recognised distinct targets. Donor- and 3rd party-reactive CTLp frequencies in 15 human cardiac allograft recipients were then measured in samples taken before transplantation, and at two intervals after transplantation. In the group of patients, donor-reactive CTLp frequencies decreased by 3 to 7 months after transplantation, but increased to pre-transplant levels by 9 to 15 months after transplantation. Donor-specific decreases in CTLp frequencies relative to the pre-transplant frequencies were found in three patients by 9 to 15 months after transplantation. Pre-transplant donor-reactive CTLp frequencies were not predictive of acute rejection in the first 3 months or in the first year after transplantation. Donor- reactive CTLp frequencies were lower at 9 to 15 months after transplantation in patients with concurrent endomyocardial biopsy (EMB) grade 2 or 3 rejection than in patients without rejection (EMB grade 0 or 1). Similarly, a negative correlation was found between donor-reactive CTLp frequencies at 9 to 15 months after transplantation and the number of EMB graded ?2 in this period. Donor-reactive CTLp frequencies were not significantly different in patients who received induction immunosuppression with anti-thymocyte globulin (ATG) and in patients who received standard triple immiunosuppression. The conclusion of all these experiments was that the Matrix 96 was comparable to the gamma counter for the measurement of 51Cr-release and was a rapid and convenient method for counting large numbers of limiting dilution assays.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Wheatley, Professor D. and Richens, Mr. D.
• Date of Award: 1999
• Depositing User: Enlighten Team
• Unique ID: glathesis:1999-71276
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 10 May 2019 10:49
• Last Modified: 02 Nov 2022 08:55
• Thesis DOI: 10.5525/gla.thesis.71276
• URI: https://theses.gla.ac.uk/id/eprint/71276