There can be wide variation in the expression of the HLA B12 antigen and its "splits," B44 and 45, on the platelets and lymphocytes from the same individual. One hundred sixty-two single donor platelet transfusions mismatched only for this antigen group were administered to 54 alloimmunized patients who were refractory to random donor platelets. Satisfactory increments (one-hour post-transfusio...

The mechanisms that regulate B cell memory and the rapid recall response to antigen remain poorly defined. This study focuses on the rapid expression of B cell memory upon antigen recall in vivo, and the replenishment of quiescent B cell memory that follows. Based on expression of CD138 and B220, we reveal a unique and major subtype of antigen-specific memory B cells (B220(-)CD138(-)) that are ...