1.2000
#25
HLA ANTIBODT IDENTIFICATION. COMPARISON BETWEEN THREE SOLID-PHASE BASED TECHNIQUES: FLOW CYTOMETRY, ELISA, AND LUMINEX.
Nancy Herrera, Wenday Wegner, Courtney Basiorka, Shonna Cotton, Sylvia Piggott, Sylvia Schwister, Tom Coley, Michele Prod and Anat R. Tambur. Chicago IL, USA, Rush U Med Ctr, 60612, HLA lab.
One of the most crucial analyses for transplant recipient candidates is the evaluation of their sera for the presence of HLA antibodies. The introduction of solid phase based techniques provided a brake through from the sensitivity, but mainly specificity, perspectives. To compare between the methods we analyzed randomly selected serum specimens from our routine patient population [213 sera specimens for class I, and 75 for class II] using Flow cytometry (FC), ELISA (E), and Luminex (L) techniques. The percent positive sera detected by each method was 57%, 46%, and 44% for class I and 27%, 24% and 31% for class II – results for FC (One lambda), E (GTI), and L (Tepnel), respectively. Comparison between the three methods is summarized in the table below.
While FC is considered to be the most sensitive methodology, we can not preclude the possibility of a false positive results, especially when both E and L detected no antinodes. However, antibody specificity was determined in the 21/24 class I and ¾ class II samples that showed F(+) and E,L(-). The percent agreement between the 3 methods was 88% and 76% for class I and class II, respectively. Luminex had the highest “false negative” rate for class I detection (based on positive result by both FC and E), and ELISA - the highest for class II.
These results indicate that a single method for antibody detection may not have sufficient sensitivity and/or specificity. We recommend that a routin screening portfolio include a minimum of 2 analysis methods.
Class I Class II All Positive 111 45 All Negative 76 12 FC,E(+) L(-) 5 1 FC,L(+) E(-) 1 3 FC,E(-) L(+) 0 5 FC,L(-) E(+) 5 3 E,L(+) FC(-) 1 2 E,L(-) FC(+) 24 4