Mouse background and IVIG dosage are critical in establishing the role of inhibitory Fc gamma receptor for the amelioration of experimental ITP

作者：Leontyev Danila; Katsman Yulia; Branch Donald R^*

来源：Blood, 2012, 119(22): 5261-5264.

DOI：10.1182/blood-2012-03-415695

A recognized paradigm for the therapeutic action of intravenous immunoglobulin ( IVIG) in immune thrombocytopenia (ITP) involves up-regulation of the inhibitory Fc gamma receptor (Fc gamma RIIB) in splenic macrophages. However, published data have indicated that opposing results are obtained when using Fc gamma RIIB-deficient mice on different strain backgrounds. Herein we show BALB/c Fc gamma RIIB-/- and wild-type, with or without spleens, all recover ITP with similar dynamics after IVIG (1 g/kg) treatment; however, this was not the case for C57BL/6 (B6) Fc gamma RIIB-/-. In investigating this conundrum, we found that wild-type B6 mice are much less sensitive than BALB/c to IVIG-mediated amelioration of ITP, requiring approximately 2- to 2.5-fold more IVIG than BALB/c. When using 2.5 g/kg IVIG in Fc gamma RIIB-/- B6 mice, amelioration of ITP was as in wild-type in all animals. Our findings led us to the conclusion that different strains of mice respond differently to IVIG and that Fc gamma RIIB plays no role in the mechanism of effect of IVIG in experimental ITP. (Blood. 2012;119(22):5261-5264)

• 出版日期2012-5-31