External Quality Assessment of Transfusion-transmissible Infections Testing

Aims: To assess the overall performance of the transfusion-transmissible infection testing laboratory through the evaluation of the results obtained from the participation in a blood proficiency testing study (B-PTS).

Study Design: The B-PTS study was designed, organized and conducted by European directorate for the quality of medicines (EDQM). We were requested to test the B-PTS samples and to report the results on the online result data sheet.

Place and Duration of Study: The 3 blood testing laboratories of the Institute of transfusion medicine in Macedonia; July 2017.

Methodology: Each set of B-PTS-samples contained 4 panels: Anti-HCV (032), anti-HIV/p24 (033), anti-Treponema (034) and HBsAg panel (035). The samples were subjected to serological testing with two assays: Enzyme immunoassay with Enzygnost system, Siemens using BEP2000 and chemiluminescent microparticle immunoassay with Architect system, Abbott using Architect i2000.

Results: The laboratories were classified as “satisfactory” for B-PTS032 and B-PTS034. For B-PTS033 the classification was “non evaluable” because the results were not properly submitted. The B-PTS035 results were classified as “unsatisfactory” because two laboratories reported the reactive sample number 3 as “Not Reactive” with the Enzygnost assay and one laboratory reported it as “Not Reactive” with the Architect assay. The single observed non-conformity was that the S/Co (1.22) of the positive control for the Architect HBsAg assay was out of rang (1.65-4.96) for the corresponding reagent lot.

Conclusion: The participation in a B-PTS study provides an objective and independent evaluation of the overall performance of the laboratory. The management of the non-satisfactory PTS results should be documented and performed in a controlled manner. Appropriate corrective and preventive measures should be taken in order non-conformities not to repeat.