Objectives: In a rat model (F344>WKY) we could clearly demonstrate, that without immunosuppression
(IS) after LTX acute rejection (AR) and CD11a-/CD18-expression reaches the maximum
at day 14 followed by a severe chronic rejection (CR) with a decrease in CD11a-/CD18-expression.
We investigated the influence of a methylprednisolon (MP)-bolus application before
and at the timepoint of AR and furthermore the efficacy of MMF on AR and CR after
too late rejection therapy.
Material and Methods: In group-I (n=20) 10mg/kgbw-MP was applicated intraperitoneally (i.p.) at day 9+10+11.
In group-II (n=20) 10mg/kgbw-MP i.p. at day 14+15+16. Group-III (n=20) received additional
treatment with 30mg/kgbw-MMF i.p. daily from day 14. 5 rats of each group were sacrified
at day 20, 30, 60, 100.
Results: In group-I AR is treated effectively with MP and no CR appears. In group-II after
MP-therapy AR was treated partly but severe CR appeared at day 60+100. Between groupI+II
was no significant difference between CD11a/CD18-expression. In group-III the amount
of AR at day 20+30 was less impressive than in group-II. At day 60+100 CR appeared
wheras vascular damage in contrast to group-II was less distinct. In group-III CD11a-/CD18-expression
was significant lower than in group I+II.
Conclusions: Early MP-treatment minimizes AR. The graft develops no CR (group-I). Late MP-therapy
at the zenith of AR (group-II) fails to controlAR and severeCR appears. Additional
MMF-application (group-III) reduces vascular and bronchial AR and vascular CR is obvious
reduced, but there is no effect on bronchial CR. CD11a/CD18-expression is significant
lower in groupIII.