[1] La Jolla Inst Immunol, La Jolla, CA USA
[2] Univ Calif San Diego, Dept Pharmacol, San Diego, CA 92103 USA
[3] Leiden Univ, Med Ctr, Dept Immunohematol & Blood Transfus, Leiden, Netherlands
[4] Univ Texas Hlth Sci Ctr San Antonio, San Antonio, TX 78229 USA