The use of combined intravenous pulse methylprednisolone and oral cyclosporin A in the treatment of corneal graft rejection: a preliminary study

Safety of Cultivated Limbal Epithelial Stem Cell Transplantation for Human Corneal Regeneration

Ex vivo cultivated limbal stem cell transplantation is a promising technique for the treatment of limbal stem cell deficiency. While the results of the clinical trials have been extensively reported since the introduction of the technique in 1997, little has been reported regarding the potential health risks associated with production processes and transplantation techniques. Culture procedures require the use of animal and/or human-derived products, which carry the potential of introducing toxic or infectious agents through contamination with known or unknown additives. Protocols vary widely, and the risks depend on the local institutional methods. Good manufacturing practice and xeno-free culture protocols could reduce potential health risks but are not yet a common practice worldwide. In this review, we focus on the safety of both autologous- and allogeneic-cultivated limbal stem cell transplantation, with respect to culture processes, surgical approaches, and postoperative strategies.

Systemic cyclosporine and corneal transplantation

Corneal transplantation is the most commonly performed tissue transplant boasting over a century of history, science, and tradition. While favorable outcomes have been reported after penetrating keratoplasty, rejection remains a major cause of graft failure. The long-term survival rates of this relatively immunologically privileged tissue are only just comparable to those of vascularized organs. While corticosteroids treatment remains the gold standard for postoperative immunomodulation, other agents have been utilized in an ongoing effort to improve graft survival and patient outcomes. One of the most promising immunomodulatory substances whose immunosuppressive effect has revolutionized solid organ transplantation is cyclosporine (CsA). A calcineurin inhibitor, cyclosporine has been used as an immunosuppressive agent in corneal transplantation since the 1980's. Although some studies have shown beneficial effects of cyclosporine in both low- and high-risk corneal transplant patients the use of cyclosporine in rejection prophylaxis and treatment remain controversial and disputable. We herein present a literature review on the role of systemic cyclosporine in corneal transplantation.

Case-control study of subconjunctival triamcinolone acetonide injection vs intravenous methylprednisolone pulse in the treatment of endothelial corneal allograft rejection

PURPOSE

To assess the safety and effectiveness of treating corneal endothelial rejection with a subconjunctival injection of 20 mg triamcinolone acetonide in combination with topical application of 1% prednisolone acetate, as compared to treatment with an intravenous pulse of 500 mg methylprednisolone in combination with topical application of 1% prednisolone acetate.

METHODS

A case-controlled study including a literature review was performed. Patients who presented with an initial episode of corneal endothelial rejection were treated with subconjunctival injection of 20 mg triamcinolone in combination with topically applied 1% prednisolone and were retrospectively matched for age and diagnosis to patients who received a single intravenous injection of 500 mg methylprednisolone in combination with topical 1% prednisolone. Patients were analysed regarding reversion of the rejection episode, intraocular pressure, and visual acuity after 1 year.

RESULTS

Overall, the triamcinolone group had a better outcome regarding reversion of corneal transplant rejection (P=0.025), with 15 of 16 patients in the triamcinolone group having clear grafts, compared to only 10 of 16 patients in the methylprednisolone group. Intraocular pressure (IOP) was increased in both groups at day 30 (P=0.002), although there was no statistically significant difference in IOP between the groups (P=0.433). Visual acuity improved in both groups after 1 year (P=0.049), although slightly more improvement was observed in the triamcinolone group (P=0.002).

CONCLUSIONS

The results observed in this case-controlled study suggest that the use of subconjunctival triamcinolone acetonide may benefit patients with corneal transplant rejection.

Corneal Graft Rejection

Penetrating keratoplasty is the most widely practiced type of transplantation in humans. Irreversible immune rejection of the transplanted cornea is the major cause of human allograft failure in the intermediate and late postoperative period. This immunological process causes reversible or irreversible damage to the grafted cornea in several cases despite the use of intensive immunosuppressive therapy. Corneal graft rejection comprises a sequence of complex immune responses that involves the recognition of the foreign histocompatibility antigens of the corneal graft by the host's immune system, leading to the initiation of the immune response cascade. An efferent immune response is mounted by the host immune system against these foreign antigens culminating in rejection and graft decompensation in irreversible cases. A variety of donor- and host-related risk factors contribute to the corneal rejection episode. Epithelial rejection, chronic stromal rejection, hyperacute rejection, and endothelial rejection constitute the several different types of corneal graft rejection that might occur in isolation or in conjunction. Corneal graft failure subsequent to graft rejection remains an important cause of blindness and hence the need for developing new strategies for suppressing graft rejection is colossal. New systemic pharmacological interventions recommended in corneal transplantation need further evaluation and detailed guidelines. Two factors, prevention and management, are of significant importance among all aspects of immunological graft rejection. Preventive aspects begin with the recipient selection, spread through donor antigenic activity, and end with meticulous surgery. Prevention of corneal graft rejection lies with reduction of the donor antigenic tissue load, minimizing host and donor incompatibility by tissue matching and suppressing the host immune response. Management of corneal graft rejection consists of early detection and aggressive therapy with corticosteroids. Corticosteroid therapy, both topical and systemic, is the mainstay of management. Addition of immunosuppressive to the treatment regimen helps in quick and long term recovery. Knowledge of the immunopathogenesis of graft rejection may allow a better understanding of the immunological process thus helping in its prevention, early detection and management.

Tolérance glycémique des bolus intraveineux de méthylprednisolone en milieu ophtalmologique

INTRODUCTION

Short-term, high-dose intravenous methylprednisolone therapy, also called pulse methylprednisolone, is widely used in a variety of inflammatory eye diseases. Monitoring blood glucose during this therapy is recommended. We evaluated the clinical implications of glycemia monitoring during repeated pulse methylprednisolone for eye disease.

PATIENTS AND METHODS

During the year 2000, 224 patients received 120-1 000 mg daily intravenous methylprednisolone for 3 consecutive days for acute optic neuritis (n=91), severe uveitis (n=35), ocular infectious diseases (n=22), corneal graft rejection (n=17) and miscellaneous disorders (n=59). Serial morning fasting blood glucose, i.e., before the first pulse and the day after each pulse, and specific hypoglycemic drug interventions were recorded.

RESULTS

All patients showed a median 50% increase in fasting glucose after the first pulse with no significant difference between diabetic and nondiabetic patients. Thereafter, the 196 nondiabetic patients showed a spontaneous decrease in their fasting glucose towards baseline values despite the following infusions. However, none of them required hypoglycemic intervention. In contrast, the 28 diabetic patients demonstrated further increases in blood glucose levels and seven received rapid-release treatment.

CONCLUSION

Glucose tolerance of pulse methylprednisolone was excellent in nondiabetic patients; close glycemia monitoring seems necessary only for patients with diabetes.

Intravenous pulse methylprednisolone therapy in eye disease: effect on glucose tolerance

PURPOSE

To determine which subjects need close glycemic monitoring during intravenous pulse methylprednisolone therapy for eye disease.

DESIGN

Retrospective study in a national eye center.

PARTICIPANTS

Two hundred twenty-four subjects who received over a one-year period 250 to 1000 mg daily intravenous methylprednisolone over 3 consecutive days for ophthalmologic conditions.

METHODS

Blood glucose monitoring during pulse methylprednisolone therapy followed a protocol written in 1995. We analyzed the effects of 3 days of pulse methylprednisolone therapy on glucose tolerance and their clinical implications in diabetic and nondiabetic subjects treated during 2000.

MAIN OUTCOME MEASURE

Serial morning fasting blood glucose; that is, before the first pulse and the day after each pulse, blood glucose self-monitoring for diabetic subjects and specific hypoglycemic drug interventions were recorded.

RESULTS

All subjects showed a median 50% increase in fasting glucose after the first steroid infusion, without a significant difference between diabetic and nondiabetic subjects. Thereafter, the 196 nondiabetic subjects showed spontaneous decreases of their fasting glucose toward baseline values despite the following infusions, whereas the 28 diabetic subjects (all type 2) demonstrated further increases of blood glucose, and 7 received rapid-release insulin to maintain blood glucose lower than 14 mmol/l. All 5 diabetic subjects with baseline glycosylated hemoglobin >/==" BORDER="0"> 8.3% required insulin therapy.

CONCLUSIONS

Close glycemic monitoring seems necessary only for subjects with diabetes during intravenous pulse methylprednisolone therapy for ophthalmologic conditions. The probability of subjects with type 2 diabetes requiring insulin during this therapy does seem to be positively related to the level of pretreatment glycosylated hemoglobin.

Long-term outcome in high-risk corneal transplantation and the influence of HLA-A and HLA-B matching

PURPOSE

To evaluate long-term follow-up of high-risk corneal transplants allocated after matching for broad HLA-A and HLA-B antigens and to establish whether matching for HLA-A and -B antigen "splits" would result in a reduced risk of immunologic graft failure.

METHODS

A total of 303 high risk corneal transplants was included. Class I antigen-matched donor corneas were obtained using broad HLA-A and -B antigen data and accepting 0 or 1 mismatch at each locus. Analysis of HLA antigens was performed also on the split typing level. The influence on immunologic graft failure for an increasing number of matched class I antigens based on split typing was analyzed with Kaplan-Meier statistics and Cox regression. Graft survival and indication for transplantation were investigated.

RESULTS

Rejection was the cause of 34% of all graft failures. A significantly higher immune failure free graft survival was found in a group with 0 or 1 HLA-A and -B mismatch based on split typing (log-rank test, P = 0.002). A beneficial effect of matching for split antigens was shown with multivariate analysis (odds ratio, 0.41).

CONCLUSIONS

One third of graft failures in our high-risk population was caused by irreversible graft rejection. Allocation of donor corneas based on a 0 or 1 split antigen mismatch at both HLA-A and -B loci could contribute to a higher immune failure free graft survival and could result in a higher overall graft survival.

Combined intravenous pulse methylprednisolone and oral cyclosporine A in the treatment of corneal graft rejection: 5-year experience

PURPOSE

To report the mid-term results of a treatment strategy using topical steroids, intravenous pulse methyl prednisolone and oral cyclosporine A (CSA) for the treatment of acute corneal graft rejection.

METHODS

Noncomparative, interventional case series. Treatment of corneal graft rejection included 1% prednisolone eye drops, intravenous infusion of 500 mg methyl prednisolone, and oral CSA in two regimens--standard dose was 15 mg/kg/day for 2 days, 7.5 mg/kg/day for 2 days, then adjusted to maintain trough blood levels of 100-200 microg/l; low dose was 2 mg/kg/day with no loading dose.

RESULTS

Outcome in 34 eyes of 34 patients (21 M;13 F) aged 60 +/- 17.7 years (range 9-83 years), who presented after an average duration of 6.6 +/- 6.3 days (range 0-30 days) following acute corneal graft rejection, are reported. Twenty-five patients received standard dose CSA while nine patients received the low dose regimen. Mean duration of treatment before reversal of graft rejection was 13.6 +/- 12.1 days (range 3-54 days). Treatment was successful in reversing the graft rejection in 32/34 (94%) eyes. Irreversible graft failure occurred in one eye in each group. During a mean follow-up period of 19.2 +/- 16.7 months (range 1-55 months), further episodes of graft rejection were seen in 1/32 (3%) eyes. Complications due to treatment included: duodenal ulcer in one patient that responded to medical treatment, and transient elevation in serum creatinine levels in three patients, which returned to normal after decrease in dosage or cessation of oral CSA.

CONCLUSION

Our 5-year experience with the use of oral CSA in the treatment of acute corneal graft rejection has shown this treatment approach to be safe and effective in reversing the rejection process. This approach may also protect the graft from subsequent episodes of allograft rejection. A randomised controlled trial to further delineate the role of CSA in reversing acute graft rejection seems warranted.