Summary Recently, in a monocentre study mycophenolate mofetil (MMF) was demonstrated to be efficacious and safe in penetrating high‐risk keratoplasty. Here, preliminary results of a randomized multicentre trial are presented. To date, 86 of 140 scheduled patients undergoing high‐risk penetrating keratoplasty have already been randomized into the two study groups: 48 into the MMF group and 38 into the control group. All 86 patients received fluocortolon 1 mg/kg body weight/day, tapered within 3 weeks, and topical prednisolone acetate 1% tapered within 5 months. MMF was administered at a daily oral dose of 2 × 1000 mg for the first 6 postoperative months. Thereafter, MMF was tapered within 2 weeks. The proportion of grafts with immune reactions and side‐effects were the main outcome measures. Within an average follow up of 9.2 ± 6.6 months two patients developed reversible endothelial immune reactions in the MMF group after cessation of MMF application. In the control group, five reversible and three irreversible immune reactions were observed within an average follow up of 10.1 ± 7.6 months. According to Kaplan and Meier analysis, the ratio of grafts without immune reactions was estimated 89% 1 year postoperatively in the MMF group, in contrast to only 67% in the control group (P = 0.03; log‐rank test). Fifteen patients experienced side‐effects, especially gastroenterotoxicity, tachycardia, arthralgia or systemic infections. All attributable side‐effects were reversible. Systemic MMF may be an effective and safe immune modulating drug in the prophylaxis of immune reactions after penetrating high‐risk keratoplasty.

Basiliximab has a lower efficacy in preventing immune reactions after risk keratoplasty than CSA. However, the side effect profile of basiliximab is more favourable than that of CSA.

Purpose It is well known that endotoxins in storage medium may stimulate cytokine production and expression of adhesion molecules as well as endothelial damage in human corneal grafts. It has been supposed that endotoxin exposure of corneal grafts may, therefore, cause immune reactions and lead to reduced endothelial cell count after penetrating keratoplasty. It was the purpose of this prospective study to evaluate if this hypothesis is true. Methods A consecutive series of 274 samples of sterile organ culture storage medium from 274 human corneal grafts was collected between August 1998 and February 1999 and tested for endotoxin using Limulus amebocytelysate assay (LAL) after 7 days of organ culture. Threshold endotoxin level was set at 1.0 U/ml. A total of 161 grafts were transplanted and 113 were discarded. Within the 161 corneas transplanted, 62 were grafted to normal-risk patients and 99 to high-risk patients. Only normal-risk keratoplasty patients were included in the study and followed for at least 10 months. Immune reactions, graft failures, and postoperative endothelial cell counts were recorded. Results The mean endotoxin level in organ culture medium of all transplanted grafts was 1.0772.96. Mean endotoxin level in organ culture medium of discarded grafts was 1.6875.76, with 71 samples being below and 42 above the threshold of 1.0 U/ml called endotoxin-negative and endotoxin-positive, respectively. In all 36 culture medium samples from the 62 grafts transplanted to the group of normal-risk keratoplasty patients were endotoxin-negative and 26 endotoxin-positive. An influence of endotoxin levels on incidence of immune reactions, graft failure, and postoperative endothelial cell counts could not be revealed in patients with normal-risk keratoplasty. Conclusion Low endotoxin levels in storage medium neither seem to promote immune reactions nor to contribute to postoperative chronic endothelial cell loss in normal-risk keratoplasty patients.