霉酚酸酯对小鼠异基因骨髓移植后急性移植物抗宿主病的预防作用

目的：探讨新型免疫抑制剂霉酚酸酯（MMF）对小鼠异基因骨髓移植（allo-BMT)后急性移植物抗宿主病（aGVHD)的预防作用。方法：用主要组织相容性抗原（MHC）完全不合的纯种近交系小鼠供鼠：雌性C57BL／6J（H－2^b)鼠；受鼠：雄性BALB／c(H-2^d)鼠]建立allo-BMT/aGVHD动物模型，随机分6组，给予MMF、环孢菌素A（CsA) 甲氨喋呤（MTX）或联合不同剂量MMF作为aGVHD预防方案。观察其aGVHD的预防作用。结果：移植小鼠出现典型的aGVHD症状，未用aGVHD预防方案的移植小鼠（第6组）死亡高峰在移植后第5－第7天，死亡率达100％。用不同aGVHD预防方案的1－5组小鼠aGVHD症状明显减轻，平均生存时间（MST）较第6组显著延长（分别延长3．4，8．4，9．0，6．1，8．8d（P＜0．05）。不同aGVHD预防方案的移植小鼠之间，移植后外周血常规变化差异无显著性。经用各预防方案后，移植小鼠cGVHD病理表现减轻，且MMF、CsA、MTX三药联合组的病理分级轻于MMF单药组或CsA MTX标准方案组。结论：MMF单药及与CsA MTX联合均能有效预防小鼠allo-BMT后的aGVHD，减轻其症状和病理损害程度，显著延长平均生存时间。小剂量MMF（≤30mg/kg）与CsA TMX的联用效果优于大剂量MMF（60mg/kg）与CsA MTX的联用效果。适当剂量的MMF（10－60mg/kg）对骨髓植入和造血恢复没有显著影响。

Prophylaxis of acute graft-versus-host disease after allogeneic bone marrow transplantation by mycophenolate mofetil in a murine model

OBJECTIVE: To evaluate the effect of mycophenolate mofetile (MMF) on acute graft versus host disease (aGVHD) prophylaxis after allogeneic bone marrow transplantation (allo-BMT) in a murine model. METHODS: Acute GVHD was induced in male BALB/c mice by total-body irradiation (TBI) followed by female allogeneic (C57BL/6J) bone marrow and spleen cells transplantation. Acute GVHD was assessed both physically and histologically. Severe aGVHD was developed in the recipients and the mean survival time (MST) of untreated BM recipients was 6 days. After allo-BMT, animals were divided into 6 groups. Group 1 was given MMF (30 mg.kg(-1).d(-1)), group 2 CsA (1.5 mg.kg(-1).d(-1)) and MTX (0.4 mg.kg(-1).d(-1)), group 3 MMF (30 mg.kg(-1).d(-1)) in combination with CsA and MTX, group 4 MMF (60 mg.kg(-1).d(-1)) in combination with CsA and MTX, group 5 MMF (10 mg.kg(-1).d(-1)) in combination with CsA and MTX, and group 6 no agents for aGVHD prophylaxis. The physical signs, MST, peripheral blood counts, and aGVHD histopathologic examination were observed in all recipients. RESULTS: Animals in control group developed typical aGVHD and 100% of mortality, with a MST of 6 days. The MSTs of group 1 approximately 5 were significantly longer than that of control, being 3.4, 8.4, 9.0, 6.1 and 8.8 days longer, respectively (P < 0.05). The MSTs of groups 2 approximately 5 were longer than that of group 1 (P < 0.05), but there was no statistical significance between groups 3 approximately 5 and 2. There was no statistical difference in peripheral blood count among groups 1 approximately 5. Histopathological examination of skin, liver, and gastrointestinal tract showed typical signs of aGVHD. Animals received immunosuppressive agents (MMF, CsA, MTX) showed the less severe signs. CONCLUSIONS: MMF markedly prolonged MST of allo-BMT recipients, delayed the onset of aGVHD signs. The prophylaxis effect of CsA + MTX with or without MMF was better than that of MMF alone, synergism between MMF of 10 or 30 mg.kg(-1).d(-1) and CsA + MTX was better than that of MMF of 60 mg.kg(-1).d(-1) and CsA + MTX.