Magic™ Anti-CD64 monoclonal antibody, clone A11.1 [APC]

BACKGROUND. Microarray analysis is considered a future diagnostic tool in leukemias. Whereas data accumulate on specific gene expression patterns in biologically defined leukemia entities, data on the correlation between flow cytometrically determined protein expression, which are essential in the diagnostic setting today, and microarray results are limited. METHODS. The results obtained by microarray analysis were compared using the Affymetrix GeneChip HG-U133 system in parallel with flow cytometric findings of 36 relevant targets in 814 patients with newly diagnosed acute and chronic leukemias as well as in normal bone marrow samples. RESULTS. In a total of 21,581 individual comparisons between signal intensities obtained by microarray analysis and percentages of positive cell as determined by flow cytometry, coefficients of correlation in the range of 0.171 to 0.807 were obtained. In particular, the degree of correlation was high in the following genes critical in the diagnostic setting: CD4, CD8, CD13 (ANPEP), CD33, CD23 (FCER2), CD64 (FCGR1A), CD117 (KIT), CD34, MPO, CD20 (MS4A1), CD7 (range of r, 0.589-0.807). CONCLUSIONS. The present data prove the high degree of correlation between findings obtained by microarray analysis and flow cytometry. They are in favor of a future application of the microarray technology as a robust diagnostic tool in leukemias.

IgG FcRs are important mediators of immunity and play a key role during Ab-based immunotherapy. Within the leukocyte IgG receptor family, only Fc gamma RI is capable of IgG binding with high affinity. Fc gamma RI exists as a complex of a ligand binding a-chain and an FcR gamma-chain. The receptors' alpha-chain can, furthermore, elicit several functions independent of the ITAM-bearing FcR gamma-chain. Functional implications of high-affinity IgG binding and mechanisms underlying FcR gamma-chain-independent signaling remain unclear to this day. In this paper, we provide an overview of past literature on Fc gamma RI and address the implications of recently described interactions between cytosolic proteins and the Fc gamma RI alpha-chain, as well as cytokine-enhanced Fc gamma RI immune complex binding. Furthermore, an analysis of potential polymorphisms within the FCGR1A gene is provided. The Journal of Immunology, 2011, 186: 2699-2704.