EXHIBIT 23.2 ARTHUR ANDERSEN LLP CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this registration statement of our report dated January 29, 1999 included in LeukoSite, Inc.'s Form 10-K for the year ended December 31, 1998 and to all references to our Firm included in this registration statement. /s/ Arthur Andersen LLP ----------------------- Arthur Andersen LLP Boston, Massachusetts December 1, 1999