P Metcalfe1, W H Ouwehand, D Sands, T W Barrowcliffe. 1. Division of Haematology, National Institute for Biological Standards and Control, South Mimms, Potters Bar, Herts, UK. pmetcalfe@nibsc.ac.uk
Abstract
BACKGROUND AND OBJECTIVES: This report describes the production of a freeze-dried preparation of pooled human plasma, coded 99/666, containing immunoglobulin G (IgG) antibodies against human platelet antigen 5b (HPA-5b). MATERIALS AND METHODS: The material is intended for use as a minimum sensitivity reagent in the assays currently used for detection of antibodies to HPA-5b. Laboratories can use it to assess the sensitivity of their 'in-house' assays for antibodies to HPA-5b and to calibrate local controls for routine use in each batch of tests. RESULTS: Two collaborative studies demonstrated that the two candidate materials contained antibodies to HPA-5b and that there were no other HPA or human leucocyte antigen (HLA) antibodies which might confuse the detection of antibodies to HPA-5b. The two samples were pooled and freeze-dried in 1-ml ampoules. CONCLUSIONS: The minimum dilution of the antibody against 5b required to yield a positive result was determined, by two international collaborative studies involving a total of 49 laboratories in 26 countries, to be 1 in 2.
BACKGROUND AND OBJECTIVES: This report describes the production of a freeze-dried preparation of pooled human plasma, coded 99/666, containing immunoglobulin G (IgG) antibodies against human platelet antigen 5b (HPA-5b). MATERIALS AND METHODS: The material is intended for use as a minimum sensitivity reagent in the assays currently used for detection of antibodies to HPA-5b. Laboratories can use it to assess the sensitivity of their 'in-house' assays for antibodies to HPA-5b and to calibrate local controls for routine use in each batch of tests. RESULTS: Two collaborative studies demonstrated that the two candidate materials contained antibodies to HPA-5b and that there were no other HPA or human leucocyte antigen (HLA) antibodies which might confuse the detection of antibodies to HPA-5b. The two samples were pooled and freeze-dried in 1-ml ampoules. CONCLUSIONS: The minimum dilution of the antibody against 5b required to yield a positive result was determined, by two international collaborative studies involving a total of 49 laboratories in 26 countries, to be 1 in 2.