[ALA-PDT alleviates graft-versus-host disease in mice following allogenic bone marrow transplantation].

OBJECTIVE: This study investigated the hypothesis that 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) might alleviate acute graft-versus-host disease (GVHD) following allogenic bone marrow transplantation (allo-BMT) in mice.

METHODS: Acute GVHD model following allo-BMT was established in 40 recipient BALB/C mice. Fifty C57BL/6J mice were used as donors and another 10 BALB/C mice as blank control without any intervention. Recipients received a lethal dose of 8.5 Gy (60)Co radiation for 10 minutes before transplantation and then were randomly divided into four groups of 10 mice (A-D). Group A was injected with normal saline injection and served as controls. Group B received pure donor bone marrow and spleen cell infusion. Group C received donor bone marrow and mixed donor-recipient spleen cell infusion. Group D was administered with an infusion of donor bone marrow cells and mixed donor-recipient spleen cells treated with ALA-PDT. The 28th day survival rate, incidence of acute GVHD and hematological and pathological changes after transplantation were examined.

RESULTS: All the mice from the Blank control group survived. The survival rates for Groups A-D on the 28th day were 0, 0, 10% and 60% respectively. Group D showed a significantly higher survival rate than the other three groups (P < 0.01). Most of the mice in Groups B and C developed GVHD but only two developed in Group D. Moreover Group D had less severe hematological and pathological changes when compared with Groups B and C.

CONCLUSIONS: ALA-PDT significantly alleviated GVHD and increased the 28th day survival rate for allo-BMT mice. ALA-PDT may be a promising therapy for GVHD following allo-BMT. Future studies should focus on the underlying mechanism of its therapeutic effect.