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148-P: Anti-endothelial cell antibodies correlate with the development of TCAD in heart transplant recipients
Abstracts
S85
147-P
INTERLABORATORY INCONSISTENCY IN KIR GENE CONTENT ASSIGNMENT PERSISTS. Arlene Locke, Marie Lau, John Muramoto, Elaine F. Reed, Raja Rajalingam. UCLA Immunogenetics Center, Department of Pathology and Laboratory, University of California at Los Angeles, Los Angeles, CA, USA. Aim: To determine the ability of HLA laboratories worldwide to accurately assess the presence and absence of 16 known KIR genes. Methods: During the past 5 years, a panel of 72 reference DNA representing 37 distinct KIR gene profiles were shipped (4 samples every 3 months) to 65 laboratories worldwide through the UCLA International KIR Exchange Program. Sixty-five percent of the labs used the SSP method, 19% used SSO, while the remaining laboratories used a combination of methods, including multiplex-SSP and Maldi-Tof. Individual laboratory results were received, compiled, and analyzed at the UCLA Immunogenetics Center. Results: Only 5 of the 72 DNAs (6.9%) were reported with KIR genotyping results in complete consensus by all laboratories. KIR genotypes of 30 samples (41.7%) did not reach consensus among the participating laboratories with inconsistent results for 3-6 loci. The most commonly mistyped loci were 3DS1 (2.3%), 2DS4 (1.6%), 2DS1 (1.3%) and 2DL3 (1.2%). Surprisingly, several of the framework genes that occur in 100% of all populations were reported as negative: 0.79% for 3DL2, 0.27% for 2DL4, 0.14% for 3DP1, and 0.13% for 3DL3. Consensus was not reached for 5 DNA samples because the number of laboratories reporting negative of 2DL3, 2DS4, 3DL2, or 3DS1 locus was equal to the number of laboratories reporting positive. Conclusions: The data revealed inconsistencies among laboratories in simple positive and negative KIR genotyping assignments, underscoring the need for continued use of reference reagents for assay and reagent validation and staff training and competency. Participation in continuing educational programs on KIR genomics may help reduce the inconsistent assignments.
148-P
ANTI-ENDOTHELIAL CELL ANTIBODIES CORRELATE WITH THE DEVELOPMENT OF TCAD IN HEART TRANSPLANT RECIPIENTS. Bhavna Lavingia, Ashley Comeaux, Zhiqiang Qin, Peter Stastny. Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA. Aim: Endothelial cells express surface antigens that are not found on peripheral blood lymphocytes. They include the MICA/MICB antigens, some autoantigens and polymorphic endothelial cell antigens that react with antibodies that appear to be associated with graft loss. The frequency and significance of the endothelial cell specific antibodies needs to be determined. Methods: We selected 38 adult heart recipients from our center with no detectable anti-HLA class I or II antibodies using single antigen bead assays (One Lambda Inc. Canoga Park, CA). Endothelial cells were isolated from human umbilical cord veins. Flow cytometry crossmatches were performed using cultured endothelial cells. Presence of anti-endothelial cell antibodies was analyzed in relation to the development of transplant related coronary artery disease (TCAD). Results: Among the patients selected for this study, 18 developed TCAD, and 20 did not. When endothelial cell antibodies were present in the recipient’s serum at the time of the transplant, 11/15 recipients developed TCAD and only 7/23 recipients without anti- endothelial cell antibodies had TCAD (X2 ⫽ 5.1; p⬍0.02). Only one of these 38 patients had anti-MICA antibodies. Conclusions: Antibodies against polymorphic surface antigens of endothelial cells were frequently found in heart recipients. Anti-endothelial cell antibodies appeared to be associated with the development of TCAD, independently of HLA or MICA, in this group of patients. A second study to confirm these findings is underway and additional results will be available for presentation.
S85
147-P
INTERLABORATORY INCONSISTENCY IN KIR GENE CONTENT ASSIGNMENT PERSISTS. Arlene Locke, Marie Lau, John Muramoto, Elaine F. Reed, Raja Rajalingam. UCLA Immunogenetics Center, Department of Pathology and Laboratory, University of California at Los Angeles, Los Angeles, CA, USA. Aim: To determine the ability of HLA laboratories worldwide to accurately assess the presence and absence of 16 known KIR genes. Methods: During the past 5 years, a panel of 72 reference DNA representing 37 distinct KIR gene profiles were shipped (4 samples every 3 months) to 65 laboratories worldwide through the UCLA International KIR Exchange Program. Sixty-five percent of the labs used the SSP method, 19% used SSO, while the remaining laboratories used a combination of methods, including multiplex-SSP and Maldi-Tof. Individual laboratory results were received, compiled, and analyzed at the UCLA Immunogenetics Center. Results: Only 5 of the 72 DNAs (6.9%) were reported with KIR genotyping results in complete consensus by all laboratories. KIR genotypes of 30 samples (41.7%) did not reach consensus among the participating laboratories with inconsistent results for 3-6 loci. The most commonly mistyped loci were 3DS1 (2.3%), 2DS4 (1.6%), 2DS1 (1.3%) and 2DL3 (1.2%). Surprisingly, several of the framework genes that occur in 100% of all populations were reported as negative: 0.79% for 3DL2, 0.27% for 2DL4, 0.14% for 3DP1, and 0.13% for 3DL3. Consensus was not reached for 5 DNA samples because the number of laboratories reporting negative of 2DL3, 2DS4, 3DL2, or 3DS1 locus was equal to the number of laboratories reporting positive. Conclusions: The data revealed inconsistencies among laboratories in simple positive and negative KIR genotyping assignments, underscoring the need for continued use of reference reagents for assay and reagent validation and staff training and competency. Participation in continuing educational programs on KIR genomics may help reduce the inconsistent assignments.
148-P
ANTI-ENDOTHELIAL CELL ANTIBODIES CORRELATE WITH THE DEVELOPMENT OF TCAD IN HEART TRANSPLANT RECIPIENTS. Bhavna Lavingia, Ashley Comeaux, Zhiqiang Qin, Peter Stastny. Internal Medicine, UT Southwestern Medical Center, Dallas, TX, USA. Aim: Endothelial cells express surface antigens that are not found on peripheral blood lymphocytes. They include the MICA/MICB antigens, some autoantigens and polymorphic endothelial cell antigens that react with antibodies that appear to be associated with graft loss. The frequency and significance of the endothelial cell specific antibodies needs to be determined. Methods: We selected 38 adult heart recipients from our center with no detectable anti-HLA class I or II antibodies using single antigen bead assays (One Lambda Inc. Canoga Park, CA). Endothelial cells were isolated from human umbilical cord veins. Flow cytometry crossmatches were performed using cultured endothelial cells. Presence of anti-endothelial cell antibodies was analyzed in relation to the development of transplant related coronary artery disease (TCAD). Results: Among the patients selected for this study, 18 developed TCAD, and 20 did not. When endothelial cell antibodies were present in the recipient’s serum at the time of the transplant, 11/15 recipients developed TCAD and only 7/23 recipients without anti- endothelial cell antibodies had TCAD (X2 ⫽ 5.1; p⬍0.02). Only one of these 38 patients had anti-MICA antibodies. Conclusions: Antibodies against polymorphic surface antigens of endothelial cells were frequently found in heart recipients. Anti-endothelial cell antibodies appeared to be associated with the development of TCAD, independently of HLA or MICA, in this group of patients. A second study to confirm these findings is underway and additional results will be available for presentation.