A final challenge with regard to MBL patients providing cellular products pertains to stem cell transplant. Although the role of allogenic stem cell transplant as a treatment for patients with CLL continues to be refined, it is a proven and routinely used therapy for selected CLL patients.(42–44) Since approximately 10% of CLL cases occur in a familial pattern(11) (10), and the prevalence of MBL is increased in such CLL families(12, 13), the question of whether relatives preparing to serve as a stem cell donor for CLL patients undergoing allogeneic transplant should undergo screening for MBL is a practical issue.(36) There is not currently consensus on whether or not matched relatives with MBL should be disqualified as donors. For many patients no alternative donor may be available and, even if available, the use of a matched unrelated donor could expose the patients to greater risk than transplant using a matched relative with MBL. Future studies are needed to clarify these issues.
