Interlaboratory Comparison of the Results of Lifecodes LSA Class I and Class II Single Antigen Kits for Human Leukocyte Antigen Antibody Detection.
BACKGROUND
Although single antigen bead assays (SAB) are approved qualitative tests, the median fluorescence intensity (MFI) values obtained from SAB are frequently used in combination with quantitative significances for diagnostic purposes. To gauge the reproducibility of SAB results, we assessed the interlaboratory variability of MFI values using identical kits with reagents from the same lot and the manufacturer's protocol.


METHODS
Six serum samples containing HLA-specific antibodies were analyzed at five laboratories by using Lifecodes LSA Class I and Class II SAB kits (Immucor, USA) from the same lot, according to the manufacturer's protocol. We analyzed the concordance of qualitative results according to distinct MFI cutoffs (1,000, 3,000, 5,000, and 10,000), and the correlation of quantitative MFI values obtained by the participating laboratories. The CV for MFI values were analyzed and grouped by mean MFI values from the five laboratories (<1,000; 1,000-2,999; 3,000-4,999; 5,000-9,999; and ≥10,000).


RESULTS
The categorical results obtained from the five laboratories exhibited concordance rates of 96.0% and 97.2% for detection of HLA class I and class II antibodies, respectively. The Pearson correlation coefficients for MFI values of class I and class II antibodies were between 0.947-0.991 and 0.992-0.997, respectively. The median CVs for the MFI values among five laboratories in the lower MFI range (<1,000) were significantly higher than those for the other MFI ranges (all P<0.01).


CONCLUSIONS
Analysis of SAB performed in five laboratories using identical protocols and reagents from the same lot resulted in high levels of concordance and strong correlation of results.
Department of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Eun-Jee
EJ
Oh
Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
Hyewon
H
Park
Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea. ; Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
Kyoung Un
KU
Park
Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Eun-Suk
ES
Kang
Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Hyon-Suk
HS
Kim
Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea. ; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology and College of Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
Eun Young
EY
Song
D000704:Analysis of Variance; D006680:HLA Antigens / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D007753:Laboratories; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results
D006680:HLA Antigens; D007518:Isoantibodies; D011933:Reagent Kits, Diagnostic
Antibody specificity; Concordance; Correlation; HLA antigens; Histocompatibility testing; Laboratories