Comparison of in-house allergen extracts of Phleum pratense (timothy grass) pollen with the international standard and investigation of IgE specificities of a grass-pollen serum pool from West Germany and of the one recommended by the World Health Organization.

We compared our in-house reference extract (RE) and a production extract (PE) with the international reference preparation (IRP) of International Union of Immunological Societies of timothy-grass pollen, using various biochemical and immunochemical methods. Furthermore, we compared the IgE composition of our in-house grass-pollen serum pool (West Germany) with the serum pool recommended by the World Health Organization, using the RE for crossed radioimmunoelectrophoresis (CRIE). Our extracts (RE and PE) were nearly comparable with the IRP. Only by CRIE one more allergen could be detected in RE and PE than in IRP and in another extract purchased from an American company. This finding may depend on the region where the source materials were harvested and which source materials were used for the preparation of the extracts. Furthermore, by high-performance liquid chromatography in the low-molecular-weight range, two distinct peaks could be detected in the nondiafiltered IRP, which were detected in the diafiltered RE and PE as traces only. The IgE composition of our in-house grass-pollen serum pool was comparable with the serum pool recommended by the World Health Organization, as detected by CRIE using RE.