Additional immunosuppression reverses inhibitory effect of CD38. IVIG or anti-CD122 antibody were administered to mice to attempt to reverse antibody-mediated clearance of cells. (A) IVIG was administered to mice before injection of 6 million cord blood cells previously incubated with either control or anti-CD38 antibody. There was a significant difference between anti-CD38 antibody and anti-CD38 antibody plus IVIG groups (P < .001), whereas there was no significant difference between control and anti-CD38 antibody plus IVIG groups (P = .09). (B) Treatment of mice with either IVIG or anti-CD122 antibody resulted in the reversal of the inhibitory effect of anti-CD38 antibody on engraftment of AML cells (sample 1; 5.7 × 106 per mouse; P < .001).
