Anti-FYB (N-terminal) polyclonal antibody

Objective: Conventional serologic typing of red blood cell systems other than ABO and RhD can be inaccurate and difficult to interpret in patients who have recently undergone blood transfusion. While molecular-based assays are not used routinely, the usefulness of genotyping was investigated in order to determine patients who may benefit from this procedure. Materials and Methods: Blood samples were taken from 101 patients with haemato-oncological, chronic renal, or gastroenterological diseases and from 50 donor controls; the samples were tested for Fy(a) and Fy(b) by applying serologic and genetic methods. All patients had received 3 or more units of RBCs during the last 3 months. An average of 6.1 RBC units were transfused per patient. The average length of time from transfusion until blood sampling was 24.4 days. The haemagglutination test was applied for serological analysis, and the restriction length polymorphism assay was used for genotyping. Results: In total, 33 (32.7%) patients showed positive reactions with anti-Fy(a) or anti-Fy(b) while being negative genetically. False-positive Fya results were found in 23 samples, and false-positive Fyb in 10 specimens. During the last 3 months, significantly more RBC units were transfused to patients with discrepant results than to those with accurate phenotyping/genotyping results: median of 5 (mean SE: 6.85 +/- 0.69) versus median of 4 (mean: 5.71 +/- 0.51), respectively (p=0.025). The median length of time after the last transfusion was 25 days (mean: 28.72 +/- 2.23 days) in the group with accurate phenotyping/genotyping results versus a median of 14 days (mean: 15.52 +/- 1.95 days) in the group with discrepant results (p=0.001). Phenotypes and genotypes coincided in all donor samples. Conclusion: Genotyping assays for the Duffy system should be considered if the patient underwent blood transfusion less than 3 or 4 weeks before the sample collection. If the time frame from RBC transfusion exceeds 6 weeks, Duffy phenotyping can provide accurate results.

The immune cell specific protein Fyn-T binding protein (Fyb) has been identified as a target of the Yersinia antiphagocytic effector Yersinia outer protein H (YopH), but its role in macrophages is unknown. By using Fyb domains as bait to screen a mouse lymphoma cDNA library, we identified a novel interaction partner, mammalian actin binding protein 1 (mAbp1). We show that mAbp1 binds the Fyb N-terminal via its C-terminally located src homology 3 domain. The interaction between Fyb and mAbp1 is detected in macrophage lysates and the proteins co-localize with F-actin in the leading edge. Hence, mAbp1 is likely to constitute a downstream effector of Fyb involved in F-actin dynamics. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.