6th ESACP Congress, Heidelberg, April 7-11, 1999

A148
CENTRAL EUROPEAN QUALITY CONTROL PROGRAM FOR IMMUNOPHENOTYPING (CEQUAL) - A REVIEW OVER SIX YEARS
Vesely R 1, VanLangendonck F 2, Mitro A 3, Strauss K 4, Barths J 5

1) Pediatric Clinic, Faculty Hospital, Kosice, Slovakia, 2) Becton Dickinson, Heidelberg, Germany, 3) Institute of Radioecology, Kosice, Slovakia, 4) Becton Dickinson France, Belgian Branch, Erembodegem, Belgium, 5) Prosort, Mönchengladbach, Germany

CEQUAL was established in 1993. 174 flow cytometry labs from Czechia, Poland, Slovakia, Hungary, Slovenia, Croatia, Bosnia-Herzegovina, Bulgaria, Romania, Yugoslavia, Latvia, Lithuania, Estonia, and Greece participated at least once; with 124 participants from 14 countries in sendaround 11. Participants receive blood samples and monoclonals for two-colour analysis of CD3-, CD4+T-cells, CD8+T-cells, NK- and B-cells. They shall also calculate the CD4/CD8 ratio and lymphsum (T+B+NK). They must analyse the sample in their own routine and can optionally apply a standardised protocol using the reagents provided. Results must be reported as percentage of lymphocytes. In optional three-colour assays the count of above-mentioned cell populations shall be reported. Results are statistically analysed using Grubbs test to identify outliers. All results are presented as graphs using confidential labcodes for each participant. All participants receive graphs with statistical analysis results. Outlying results are analysed individually. All available list-mode files are re-analysed. When possible sources of error can be identified, advice is given to the participant how to avoid them. Overall reviews of main error sources are communicated to all participants. CEQUAL is to our knowledge the only international QC-program for immunophenotyping functioning for such a long time. Although except for Czechia no external QC is required for accreditation, the flow cytometry community appreciates the program as the high participation shows (over 65 % of all labs concerned). The program helps educating the participants in preventing the most common errors (gating, quadrant-correction, gate contamination, cell-population calculation etc.) and helps to standardise flow cytometric results in the territory.