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Abstracts / Human Immunology 74 (2013) 483–499
OLERUP US XM-ONE PROFICIENCY TESTING (PT) PROGRAM UPDATE. Manuel Carreño 1, Annette Jackson 2, Bruno Vanherberghen 3, Håkan Hall 3. 1 Olerup Inc., West Chester, PA, USA; 2 John Hopkins University, Baltimore, MD, USA; 3 AbSorber AB, Stockholm, Sweden. Aim: The XM-ONE PT program is designed to emulate and evaluate clinical testing for Non-HLA antigen present on endothelial cells (EPC). The PT program was initiated in 2011 with the motion to assess performance of the EPC crossmatch within the US. We report here results of the initial 2011 and the second, the 2012-I Survey. Methods: In 2011 five centers received and reported results for IgG and IgM. The 2012-I was sent out to 10 centers. Seven of them reported both IgG and IgM results while two others reported results for the IgG only. One laboratory did not submit results. Both surveys included two whole blood target cells specimens and five analytes. In addition, a negative control and positive control for IgG and IgM was supplied with each shipped kit. In the assessment and evaluation, only the clinical diagnosis (Positive or Negative) was taken into consideration. Nevertheless, all steps of the test were meticulously examined to explain the posted diagnosis. Results: The 2011 survey had 100% successful participation for all centers. IgG had a 100% consensus while IgM showed some minor difficulties due to the methods and technicalities in the setting of the ‘‘cut off channels’’ or ‘‘ratios’’ for IgM by the different centers. In the 2012-I there was 100% successful participation for all participants. For IgG one center missed 1/5 analytes while for IgM two lab missed 1/5 analytes (in both cases with one of the cell targets). Conclusions: The survey results indicate solid base consensus but there is still room for improvements. We continue our commitment to maximize the educational aspects of these exercises and improve future XMONE PT surveys. Implementation of the more complete T cell (TC) and B cell (BC) Lymphocytes and EPC combined XM-ONE assay (3-in-1) into the XM-ONE PT program is planned for future PT exercises. The 3-in-1 version of XM-ONE can reduce cost and time in many laboratories by covering HLA and Non-HLA specific antigens within one test. In future PT exercises PT participants may choose to report results for the XM-ONE test (EPC) or the 3-in-1 XM-ONE test (EPC), (TC), (BC).
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UNEXPLAINED POSITIVE REACTIONS WITH ONE LAMBDA, FLOWPRATM
LOT #18. Robert A.Bray, Linda
McLachlan, Pam Chapman, Nalaja Marcus, Howard M.Gebel. Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA. Aim: Minimizing lot-to-lot variability should be a primary goal for all manufacturers of diagnostic products. Nonetheless, it is the responsibility of each laboratory to verify that a new lot or reagent performs as expected. Here we discuss concerns related to quality control of the FlowPRA test by One Lambda, Inc. Methods: Initial testing of the new lot (#18) of FlowPRA Class II screening beads was performed using samples with and without HLA antibodies as determined with the previous lot (#17) of FlowPRA. All samples were run according to manufacturers’ recommended specifications with the exception of using 40ul of serum instead of 20 ul. Samples were analyzed on a FACS Canto II instrument. Results: Testing of sera that contained known HLA antibodies were comparable between lots. However, unexpected positive reactions consistently were observed with lot #18 when HLA antibody negative sera were tested. As a follow up, samples from 10 such patients were tested by single antigen beads (SABs, LabScreen, One Lambda, Inc.). In addition, historic samples, shown to be devoid of HLA Class II antibody (FlowPRA Lot #17), were retested against the new lot of FlowPRA beads. Of concern was the observation that all 10 historic 0% PRA samples were now positive with the new bead lot. Importantly, testing by SABs confirmed the absence of Class II antibodies. Conclusions: Our results clearly demonstrate a problem with lot #18 Class II FlowPRA beads. Lot #18 differs from the previous lot by a single bead. Although this bead carries a new phenotype, it added only one new allele (DPB*02:02) to the collection of alleles compared to FlowPRA lot #17. The unexpected reactivity is most likely due to non-HLA antibodies since the possibility of multiple patients expressing a solitary DPB*02:02 antibody is not likely. Such false positive reactivity should have been identified by the manufacturer. Failure to do so ultimately translates into wasted time, effort and expense. More importantly, patient care may be compromised by reporting of false positive results.
1005-LB
Abstracts / Human Immunology 74 (2013) 483–499
OLERUP US XM-ONE PROFICIENCY TESTING (PT) PROGRAM UPDATE. Manuel Carreño 1, Annette Jackson 2, Bruno Vanherberghen 3, Håkan Hall 3. 1 Olerup Inc., West Chester, PA, USA; 2 John Hopkins University, Baltimore, MD, USA; 3 AbSorber AB, Stockholm, Sweden. Aim: The XM-ONE PT program is designed to emulate and evaluate clinical testing for Non-HLA antigen present on endothelial cells (EPC). The PT program was initiated in 2011 with the motion to assess performance of the EPC crossmatch within the US. We report here results of the initial 2011 and the second, the 2012-I Survey. Methods: In 2011 five centers received and reported results for IgG and IgM. The 2012-I was sent out to 10 centers. Seven of them reported both IgG and IgM results while two others reported results for the IgG only. One laboratory did not submit results. Both surveys included two whole blood target cells specimens and five analytes. In addition, a negative control and positive control for IgG and IgM was supplied with each shipped kit. In the assessment and evaluation, only the clinical diagnosis (Positive or Negative) was taken into consideration. Nevertheless, all steps of the test were meticulously examined to explain the posted diagnosis. Results: The 2011 survey had 100% successful participation for all centers. IgG had a 100% consensus while IgM showed some minor difficulties due to the methods and technicalities in the setting of the ‘‘cut off channels’’ or ‘‘ratios’’ for IgM by the different centers. In the 2012-I there was 100% successful participation for all participants. For IgG one center missed 1/5 analytes while for IgM two lab missed 1/5 analytes (in both cases with one of the cell targets). Conclusions: The survey results indicate solid base consensus but there is still room for improvements. We continue our commitment to maximize the educational aspects of these exercises and improve future XMONE PT surveys. Implementation of the more complete T cell (TC) and B cell (BC) Lymphocytes and EPC combined XM-ONE assay (3-in-1) into the XM-ONE PT program is planned for future PT exercises. The 3-in-1 version of XM-ONE can reduce cost and time in many laboratories by covering HLA and Non-HLA specific antigens within one test. In future PT exercises PT participants may choose to report results for the XM-ONE test (EPC) or the 3-in-1 XM-ONE test (EPC), (TC), (BC).
1006-LB
UNEXPLAINED POSITIVE REACTIONS WITH ONE LAMBDA, FLOWPRATM
LOT #18. Robert A.Bray, Linda
McLachlan, Pam Chapman, Nalaja Marcus, Howard M.Gebel. Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA. Aim: Minimizing lot-to-lot variability should be a primary goal for all manufacturers of diagnostic products. Nonetheless, it is the responsibility of each laboratory to verify that a new lot or reagent performs as expected. Here we discuss concerns related to quality control of the FlowPRA test by One Lambda, Inc. Methods: Initial testing of the new lot (#18) of FlowPRA Class II screening beads was performed using samples with and without HLA antibodies as determined with the previous lot (#17) of FlowPRA. All samples were run according to manufacturers’ recommended specifications with the exception of using 40ul of serum instead of 20 ul. Samples were analyzed on a FACS Canto II instrument. Results: Testing of sera that contained known HLA antibodies were comparable between lots. However, unexpected positive reactions consistently were observed with lot #18 when HLA antibody negative sera were tested. As a follow up, samples from 10 such patients were tested by single antigen beads (SABs, LabScreen, One Lambda, Inc.). In addition, historic samples, shown to be devoid of HLA Class II antibody (FlowPRA Lot #17), were retested against the new lot of FlowPRA beads. Of concern was the observation that all 10 historic 0% PRA samples were now positive with the new bead lot. Importantly, testing by SABs confirmed the absence of Class II antibodies. Conclusions: Our results clearly demonstrate a problem with lot #18 Class II FlowPRA beads. Lot #18 differs from the previous lot by a single bead. Although this bead carries a new phenotype, it added only one new allele (DPB*02:02) to the collection of alleles compared to FlowPRA lot #17. The unexpected reactivity is most likely due to non-HLA antibodies since the possibility of multiple patients expressing a solitary DPB*02:02 antibody is not likely. Such false positive reactivity should have been identified by the manufacturer. Failure to do so ultimately translates into wasted time, effort and expense. More importantly, patient care may be compromised by reporting of false positive results.