The International HLA DNA Exchange was established in 1993 with 63 participants. The goal of the exchange was to provide samples of DNA from the same individuals to laboratories for testing and to compare the results obtained using different methods and different reagents. The exchange has been graded since 1993 and many laboratories have used their participation in the exchange to satisfy proficiency testing requirements. Currently, 125 laboratories participate in the exchange (worldwide participation page). The end of 2001 marked the completion of 51 DNA exchanges, including 330 preparations for Class II DNA typing, and 221 for Class I DNA typing. The participating laboratories employ a variety of PCR-SSP and PCR-SSO DNA typing approaches, but the number of laboratories reporting direct sequencing of HLA genes is increasing.
The results of the DNA exchanges have shown a very high concordance among laboratories performing DNA-based HLA typing. The exchanges have confirmed the superior inter-laboratory accuracy and reproducibility of DNA typing methods when compared with the results of serological testing. The DNA exchanges have also provided a bank of extremely well characterized DNA samples, with alleles confirmed by many laboratories using different methods. These samples have been assembled, catalogued and can be purchased individually or in panels (see reference panel section).
The International HLA DNA Exchange allows laboratories to validate methods and procedures, serves as an external QC program to meet American Society of Histocompatibility and Immunogenetics accreditation requirements for DNA proficiency testing. The Exchange is also accepted by the European Federation of Immunogenetics and by New York State Department of Health. It also serves as an external QA program to check outside assessment of performance. Every two months, 6 samples of DNA (60 µl at > 1,000 µg/ml ) are sent out. Six weeks are allowed for testing. The result of each Exchange is scored and an individualized report of the labs performance is sent along with the following sendout. The DNA Exchange offers:
Please use WHO designated allele nomenclature. For the most complete and up-to-date information on alleles, use the IMGT/HLA database.