Objective: To determine the differences of the effect of ultraviolet-B(UVB) on lymphocyte and hematopoietic progenitor cell in cord blood.
Methods: The viability, proliferative response and stimulatory activity in mixed lymphocyte culture (MLC), colony forming unit-granulo-monocyte (CFU-GM) colony growth and percentage of CD34+ cell of cord blood in Hanks medium after 0, 5, 10, 20, 50 mJ/cm2 UVB-irradiation were compared.
Results: Like the proliferative response and stimulatory activity, CFU-GM colony also showed UVB-irradiation dose dependent decrease. However, much less colonies were destroyed by UVB irradition less than 10 mJ/cm2. More obvious differences were found when 20%(vol/vol) bovine serum was added to the MNC medium. The percentage of CD34+ cell remained unchanged after UVB exposure.
Conclusion: A lower dose of UVB exposure can slectively inactivate cord blood lymphocyte and antigen presenting cell while sparing hematopoietic progenitor cells. The data indicates the possibility of utility of UVB irradiation for graft-versus-host disease prophylaxis in cord blood transplantation.