Survival of rabbit limbal stem cell allografts after administration of cyclosporin A.

OBJECTIVES: To evaluate the efficacy of systemic or topical administration of cyclosporin A (CsA) after limbal transplantation of stem cell allografts in rabbits. METHODS: Thirty-six rabbits underwent corneal epithelial debridement and limbal ablation to induce ocular surface disease and were then treated by limbal allograft transplantation. Animals received either systemic CsA (10 mg/kg per day, intramuscularly), 1% CsA eyedrops, or vehicle eyedrops immediately after transplantation and 28 days thereafter. Concentration of CsA in plasma and aqueous humor was determined by fluorescence polarization immunoassay after 4 weeks of therapy. Graft survival was inspected clinically. RESULTS: Both systemic and topical administration of CsA resulted in a significant prolongation of graft survival. In addition, one of seven of the limbal allografts in either group of systemic and topical CsA survived >60 days on cessation of CsA. There was no significant difference in mean survival time between systemic and topical application, although plasma levels of CsA were significantly higher after systemic administration. However, a significant higher aqueous concentration was found in topical treatment. CONCLUSIONS: Limbal allografts were stable in maintaining the reconstructed ocular surface under attentive postoperative immunosuppression. Topically administered CsA was as effective as systemic use.     

国产环孢素A眼液治疗大鼠角膜移植术后免疫排斥反应的研究

目的　观察环孢素A(cyclosporine,CsA)滴眼液对鼠角膜移植术后免疫排斥反应的治疗效果。方法　随机对纯系大鼠LOU65只为受体及F344纯系大鼠33只为供体建立的角膜移植术后免疫排斥反应动物模型分为6组,各组分别于手术后滴用0.5%CsA、1.0%CsA、2.0%CsA、糖皮质激素、糖皮质激素和1.0%CsA及CsA基质滴眼液,观察角膜移植术后植片排斥反应指数(rejectionindex,RI),植片平均存活时间(meanssurvivaltime,MST),并对角膜植片进行病理学检查及免疫病理学分析。结果0.5%CsA、1.0%CsA、2.0%CsA、糖皮质激素及混合组的植片MST均较对照组延长1.63～8.46d,其中2.0%CsA组、糖皮质激素组及混合组的植片MST延长与其他组比较差异有显著性（t≥2.28,P<0.01）,混合组为（15.71±5.06）d。对照组的角膜植片排斥RI较其他组高,其中2.0%CsA组与糖皮质激素组的角膜植片排斥RI一致,分别为5.34±1.92和5.18±1.69;混合组治疗效果最好,RI为4.31±1.50,而CsA滴眼液治疗后大鼠血清中的浓度介于21.6～62.2mg/L。病理学检查各治疗组角膜植片淋巴细胞浸润减轻,新生血管减少;免疫病理显示,除0.5%CsA组外,其余各组的淋巴细胞相关抗原1（LFA-1,CD+11a）、ICAM-1表达和巨噬细胞浸润均明显减少。结论　环孢素A滴眼液能够抑制大鼠角膜移植术后免疫排斥反应的发生,与糖皮质激素联合应用能取得更佳的效果。     

Long-term outcome of topical cyclosporine treatment following penetrating keratoplasty]

PURPOSE: To evaluate the long-term outcome of 2% topical cyclosporine A (CsA) treatment as an adjunct to topical corticosteroid in 86 eyes after penetrating keratoplasty (PK). MATERIAL AND METHODS: The subjects were 86 eyes of 83 patients who had undergone PK and received topical CsA treatments. Ninety-seven eyes of 95 patients who had undergone PK and received similar postoperative treatments except for topical CsA treatments served as control: The clinical outcome of PK was evaluated by rates of graft survival and rejection-free graft survival using Kaplan-Meier's method and compared with the log-rank test. The patients were subdivided into high-risk and low-risk groups. The high-risk patients were those who had corneal vascularization in 2 or more quadrants of the cornea preoperatively or who received regrafting. All other patients were assigned to the low-risk group. Thirty-six eyes of the CsA group and 50 eyes of the control group were high-risk cases. RESULTS: In the high-risk patients, the rejection-free graft survival rate was 69.7% in the CsA group and 45.4% in the control group (p = 0.030). However, there was no significant difference in the graft survival rate between the two groups. In the low-risk patients, there was no significant difference in the rates of rejection-free graft survival and graft survival between the CsA and the control group. CONCLUSION: 2% topical cyclosporine is effective in reducing the risk of allograft rejection in high-risk recipients.     

Prolongation of corneal allograft survival using cyclosporine in a polylactide-co-glycolide polymer

PURPOSE: To test for prolongation of corneal transplant survival with cyclosporine in a polymer placed in the anterior chamber of corneal allograft recipients. METHODS: Wistar inbred rats with vascularized corneas were recipients of corneal allografts from Sprague-Dawley donor rats. Grafted rats were randomized into six groups: untreated control animals, cyclosporine-polymer anterior chamber recipients, cyclosporine-polymer subconjunctival recipients, cyclosporine-olive oil drop recipients, polymer-only anterior chamber recipients, and autografted Wistar rats. Grafts were examined by slit lamp every 3 days and the clinical condition scored. The cyclosporine concentration in the aqueous humor was assayed at 1, 2, and 4 weeks. At 2 and 4 weeks after transplantation, the eyes were collected for histopathologic evaluation of the grafts. RESULTS: The median survival time of untreated corneal allografts was 8.2 +/- 1.48 days for grafts treated with topical cyclosporine, 8.5 +/- 1.50 days for polymer-only anterior chamber implants, 10.6 +/- 1.90 days for 1% cyclosporine drops, 11.4 +/- 2.50 days for grafts given subconjunctival cyclosporine-polymer, 17 +/- 3.05 days for grafts given cyclosporine-polymer implants in the anterior chamber, and more than 3 months in autografted rats. There was a statistically significant difference ( p < 0.05) between the survival time of the allografts in the animals treated with the cyclosporine-polymer in the anterior chamber compared with the other groups of graft recipients. Significantly higher concentrations of cyclosporine were found in the eyes given an anterior chamber implant of cyclosporine-polymer than in the other treatment groups or the untreated rats. The cyclosporine-polymer implants placed in the anterior chamber induced a transient inflammatory response in transplanted eyes. CONCLUSIONS: Cyclosporine-polymer placed in the anterior chamber significantly prolongs corneal allograft survival in a high-risk corneal graft rejection. This intraocular delivery system may be a valuable adjunct for the suppression of immune graft rejection in high-risk recipients of corneal transplants.     

Efficacy and safety of microspheres of cyclosporin A,a new systemic formulation,to prevent corneal graft rejection in rats

PURPOSE: To evaluate the efficacy and safety of a new systemic formulation of cyclosporin A (CsA)-loaded microspheres in a rat model of penetrating keratoplasty rejection. METHODS: Female Lewis rats received orthotopic corneal allografts from inbred female Fisher donors. The rats were divided into three groups: 1, untreated controls; 2, daily subcutaneous injection of 10 mg/kg of the commercially intravenous CsA formulation starting after surgery (time 0) and for 15 days; and 3, one subcutaneous injection of 150 mg/kg of CsA microspheres. The grafts were evaluated clinically for 30 days and the rejection index, mean survival time, and rejection rate were calculated. Serum levels of CsA were measured at 5, 10, 15, 20, and 30 days in groups 2 and 3. Eyes, liver, and kidneys were histologically evaluated at the end of the experiment. RESULTS: Graft rejection was significantly reduced in group 3 at day 30 (P < 0.05) and serum levels of CsA were constant (range, 73.28 +/- 43.93 to 183.33 +/- 83.69 ng/ml). High levels (>3000 ng/ml) were obtained in group 2 as long as CsA was injected. Both formulations delayed rejection onset, but only the microspheres decreased the rate of corneal graft rejection (100% in group 2 and 70% in group 3 at day 30). Histologic examination showed no hepatic lesions with either formulation, but both resulted in deposition of a hemoglobin-like material in the kidneys. CONCLUSIONS: Although subcutaneous CsA-loaded microspheres delay rejection onset and decrease the rate of corneal graft rejection in an orthotopic keratoplasty rejection model in rats, administration of the microspheres did not prevent acute renal toxicity.     

Long-term effects of topical cyclosporine A treatment after penetrating keratoplasty

PURPOSE: To evaluate the long-term outcome of topical 2% cyclosporine A (CsA) treatment as an adjunct to topical corticosteroid treatment of patients after penetrating keratoplasty (PKP). METHODS: We reviewed the records of 83 patients (86 eyes) who had undergone PKP and received topical CsA treatment postoperatively; also the records of 95 PKP patients (97 eyes) who received the same treatment, except for the 2% CsA eyedrops, and served as controls. The patients were also subdivided into high-risk and low-risk groups. The clinical outcome of PKP was evaluated by the rates of graft survival and rejection-free graft survival, using the Kaplan-Meier method, and compared with the log-rank test. RESULTS: In the high-risk patients, the rejection-free graft survival rate was 69.7% in the CsA group and 45.4% in the control group (P =.030), but there was no significant difference in the graft survival rate between the two groups. CONCLUSION: Topical cyclosporine treatment is effective in reducing the risk of allograft rejection in high-risk patients.     

The effect of corticosteroid and cyclosporin A on murine corneal allograft rejection

Background: The immunomodulatory T-helper type 1 (Th1) cytokine interferon-γ (IFN-γ) was measured in serum and cornea to ascertain its general contribution to corneal graft rejection and to establish a rational basis for the decision for or against systemic therapy. Methods: Eight groups of differently treated BALB/c (H-2d) mice received a C3H (H-2 k) corneal graft. There was one saline-treated control group and two groups that received intramuscular cyclosporin A (CsA) for 14 or 40. Three groups received systemic or topical, systemic plus topical corticosteroid treatment, which was combined with CsA in two further groups. To measure the IFN-γ level by enzyme-linked immunosorbent assay (ELISA), blood was taken by heart puncture and corneae were excised at the limbus. Results: Five days of systemic corticosteroid and 14 days of CsA had no significant effect on graft survival. A 40-day CsA treatment and a 40-day combined corticosteroid treatment significantly prolonged graft survival. An 80-day topical corticosteroid treatment produced additional prolongation. IFN-γ could not be detected (limit of detection 25 pg/ml) in any of the serum samples, while significantly increased amounts of IFN-γ were detected in the supernatants of the corneal tissue 13 or 14 days after allogeneic but not syngeneic corneal graft, corresponding to 9.5 pg, 5.1 pg and 1.8 pg per cornea. Conclusion: The detection of Th1 cytokines in the cornea but not the serum of mice at the time of allograft rejection is in accordance with the finding of long-lasting dose-dependent immunosuppression of topical steroids and the inefficacy of short-term systemic CsA and corticosteroids. Received: 8 November 1999 Revised: 7 February 2000 Accepted: 9 February 2000     

Leflunomide抑制大鼠角膜移植免疫排斥反应的研究

目的研究Leflunomide对大鼠角膜移植排斥反应的防治作用。方法建立大鼠穿透性角膜移植排斥反应的动物模型,观察Leflunomide对大鼠角膜植片存活和排斥反应指数（RI）的影响,并与阴性对照组和CsA治疗组相比较。结果阴性对照组角膜植片存活时间为12.375d±1.768d,而CsA组为17.375d±1.408d,Leflunomide组为18.250d±1.356d,均比阴性对照组显著延长（P<0.01）。结论Leflunomide能抑制大鼠穿透性角膜移植免疫排斥反应,显著延长角膜植片的存活时间。     

Penetrating keratoplasty in the rat: a model for the study of immunosuppressive treatment of graft rejection

The present study reports corneal allogeneic transplantation in a rat model. The technique used was full-thickness penetrating keratoplasty. Fisher rats were used as donors and Lewis rats were used as recipients. The rate of acute rejection obtained in this model with this combination of strains was 100%. It therefore seems to be a very useful model for the study of rejection and for the study of new immunosuppressive treatment. The effect of systemic cyclosporine (CsA) treatment on graft rejection was assessed using this model. Rejection was prevented by CsA as long as treatment was given but occurred in most grafts within 10 days of treatment cessation. Thus, tolerance could not be induced with CsA which, however, significantly reduced graft neovascularization.     

Efficacy of systemic cyclosporine A and amniotic membrane on rabbit conjunctival limbal allograft rejection

PURPOSE: To evaluate the effect of intramuscular cyclosporine A (CsA) and amniotic membrane (AM) on conjunctival limbal allograft survival in a rabbit model. METHODS: Eighty-two female rabbits (59 New Zealand white rabbits, 23 Dutch pigmented rabbits) were used. The New Zealand white rabbits were divided into 4 treatment groups: group 1 (n=13), conjunctival limbal autograft transplantation; group 2 (n=12), conjunctival limbal allograft transplantation without additional treatment; group 3 (n=18), conjunctival limbal allograft transplantation and human AM; and group 4 (n=16), conjunctival limbal allograft transplantation and systemic CsA (10 mg/kg/day intramuscularly). The 23 Dutch pigmented rabbits were used as limbal stem cell allograft donors. The rejection index, the mean survival time, and the rejection rates were calculated for each group. RESULTS: After 28 days of follow-up, there were no episodes of limbal rejection in groups 1 and 4, whereas the rejection rate was 100% in groups 2 and 3. There was no significant difference in mean survival time of the rejected grafts between groups 2 and 3. CONCLUSIONS: A model of rejection of conjunctival limbal transplantation was developed in the rabbit. Intramuscularly injected CsA effectively prevents limbal allograft rejection. Human AM is not useful for this purpose.     

Long-term outcome of systemic cyclosporine treatment following penetrating keratoplasty

PURPOSE: To perform a retrospective study to evaluate the long-term outcome of systemic cyclosporine treatment as an adjunct to topical corticosteroid treatment after penetrating keratoplasty (PKP). METHODS: Twenty-six high-risk patients (27 eyes) who received systemic cyclosporine following PKP for an average of 5.4 months were compared with another series of 57 patients (57 eyes) who did not receive cyclosporine after PKP. RESULTS: Endothelial rejection developed in 2 cases during cyclosporine treatment and in 6 cases after discontinuation. The rate of rejection-free graft survival was similar between the treated and the control groups. The control group showed a significantly higher rate of graft survival than the treated group. As side effects in the treatment group, transient elevation in blood urea nitrogen or creatine developed in 7 cases. Increase in glutamate oxaloacetate transaminase (GOT) or glutamate pyruvate transaminase (GPT) developed in 4 cases. Severe side effects were absent throughout the series in both groups of patients. CONCLUSION: Systemic cyclosporine treatment for several months did not reduce the incidence of rejection nor improve the rate of graft clarity in the long term in high-risk patients after PKP.     

对大鼠角膜移植免疫排斥反应的抑制作用

目的     

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.     

FK-506抑制大鼠角膜移植免疫排斥反应的研究

目的建立近交系大鼠穿透性角膜移植动物模型,观察结膜下注射ＦＫ５０６对角膜移植免疫排斥反应的抑制作用。方法将近交系Ｌｏｕ大鼠２８只作受体,１４只Ｆ３４４大鼠作供体,分为３组,术后结膜下分别按每公斤体重注射０．１ｍｇＦＫ５０６、３ｍｇＣｓＡ及生理盐水,共２周。对角膜植片进行临床观察,以混浊、水肿和新生血管３项指标作为临床评估标准。结果３组角膜植片的存活时间分别为（２２１±５１７）、（１８４±１４）及（１２１±２１３）天,三者间差异有显著性（Ｐ＜０．０１）。结论ＦＫ５０６能显著延长大鼠角膜植片的存活时间,是一种有效的新型免疫抑制剂。     

前房植入环孢素A缓释系统抑制鼠高危角膜移植术后的免疫排斥反应

目的　探讨前房内植入环孢素A缓释系统 (cyclosporineAdrugdeliverysystem ,CsADDS)抑制高危角膜移植术后免疫排斥反应的有效性和可行性。方法　 (1)对 6 0只Wistar大鼠 (6 0只眼 )用缝线法诱导角膜新生血管增生。 (2 )将发生角膜新生血管化的 4 0只Wistar大鼠 (40只眼 )随机分为4组 :对照组 ,1%CsA滴眼组 ,CsADDS结膜下植入组 ,CsADDS前房内植入组。每组均接受同种异系(Spregue Dawley大鼠 )角膜供体 ,行穿透性角膜移植术 ,术后比较各组大鼠免疫排斥反应发生的时间 ,并定期检测各组大鼠房水中CsA的浓度。 (3)正常Wistar大鼠 8只 (16只眼 ) ,随机分为 2组 ,分别在结膜下和前房内植入CsADDS ,术后 2和 4周行眼的组织病理学检查。结果　 (1) 5 1只Wistar大鼠 (5 1只眼 )经角膜基质缝线 ,成功诱导角膜新生血管增生。 (2 ) 4组共 4 0只Wistar大鼠角膜移植术后免疫排斥反应的发生时间分别为 :对照组 (8 2 0± 1 4 8)d ,1%CsA滴眼组 (10 6 0± 1 90 )d ,CsADDS结膜下植入组 (11 4 0± 2 5 0 )d ,CsADDS前房内植入组 (17 0 0± 6 0 5 )d。房水中CsA浓度均值分别为 :对照组 0 μg/L ;1%CsA滴眼组 (47 90± 3 4 8) μg/L ;CsADDS结膜下植入组术后 1、2、4周 ,房水中CsA浓度均值分别为 (5 9 0 0± 3 6 6 ) μg/     

Efficacy of subconjunctival cyclosporin-containing microspheres on keratoplasty rejection in the rabbit

· Background: The purpose of this study was to evaluate microspheres of PLGA containing cyclosporin (CsA) as a subconjunctival drug delivery system and to test their efficacy in the prevention of corneal allograft rejection in the rabbit. · Methods: Rabbits were injected subconjunctivally with a solution of CsA (CsA-AR) (20 animals) or a microsphere suspension of CsA (CsA-MP) (20 animals), with equivalent drug concentrations (15 mg/ml). The concentration of CsA in the aqueous, cornea and blood was measured by radioimmunoassay at different times thereafter. In other rabbits, 40 allogeneic grafts were performed. Animals were divided into four groups that received the following subconjunctival treatments: group 1: AR solution (solvents of CsA-AR solution); group 2: CsA-AR solution; group 3: MP suspension (empty microspheres); group 4: CsA-MP suspension. · Results: Mean corneal levels of CsA were 1174±830, 918±179, 972±580, 268±182 and 243±162 ng/ml at 12, 24 and 48 h and 7 and 14 days after the injection of CsA-AR. For the CsA-MP suspension, corneal concentrations were 1195±321, 234±147 and 88±77 ng/ml at 12, 24 and 48 h but subsequently dropped to undetectable levels. Blood and aqueous levels were undetectable. Treatment with CsA significantly improved the survival time and survival rate of grafts in the CsA-treated groups (2, 4) over grafts in non-CsA-treated groups (1, 3). There was no significant difference in the graft survival curve between groups 2 and 4. · Conclusion: CsA-containing microspheres might be a promising formulation in the prevention of corneal graft rejection. Since the levels of CsA in blood were undetectable, this treatment might avoid the problems associated with systemic side effects. Received: 28 October 1998 Revised version received: 5 February 1999 Accepted: 2 March 1999     

环孢素A缓释系统植入前房抑制鼠角膜移植免疫排斥反应机制的研究

目的　探讨前房植入环孢素A(cyclosporineA ,CsA)缓释系统抑制鼠角膜移植免疫排斥反应的机制。方法　 (1)环孢素A缓释系统的制备 :为CsA粉剂与已交酯 丙交酯 已内酯的三元共聚物混合体 ,每粒含环孢素A 0 5mg。 (2 )对 90只 (90只眼 )BALB c鼠 (受体 )行穿透性角膜移植术 ,将其分为A、B、C组 ,每组 30只。供体为C5 7BL 6鼠。A组术中鼠前房植入CsA缓释系统 ;B组术中鼠前房植入不含CsA的空白缓释系统 ;C组术后不作任何处理作为正常对照组。术后 3d用裂隙灯显微镜观察角膜植片情况 ,记录角膜植片免疫排斥反应发生的时间和程度。各组分别于术后 1、2、4及 6周随机取 2只鼠眼行组织病理学检查 ,并用CD4、CD8及CD11B单克隆抗体行免疫组织化学染色 ,观察各组T淋巴细胞的迁移和数量。结果　A组鼠角膜植片排斥时间平均 (35± 3)d ,较B、C组 (14± 3)d明显延长 (P <0 0 0 1)。前房植入的CsA缓释系统体积缩小前 ,A组角膜植片均保持透明 ;当前房植入的CsA缓释系统消失后 ,角膜出现免疫排斥反应 ,植片逐渐混浊、增厚、血管化。B、C组免疫排斥反应均在术后 2周发生。组织病理学和免疫组织化学检查 :A组在术后 14d仅于植床角膜可见少量CD+ 4 　和CD+ 8　细胞浸润 ,在虹膜和睫状体中未见CD+ 11B、CD+ 4 、CD+ 8　T淋     

Prevention of corneal allograft rejection in a mouse model of high risk recipients

AIM: To determine the effectiveness of treatment with immunosuppressive drugs and monoclonal antibodies (mAb) after penetrating keratoplasty in two different models of high risk mouse recipients. METHODS: Corneas were grafted orthotopically in mouse models of high risk recipients with either neovascularisation of the graft bed or presensitisation to graft donor antigens. Recipients were treated with mAb against CD4(+) or CD8(+) cells or against T cells, or were treated with cyclosporin A (CsA) or mycophenolate mofetil (MMF), or a combination of both drugs. RESULTS: Control untreated recipients with neovascularised graft bed or presensitised to the graft donor antigens rejected corneal allografts in 12.5 (SD 2.3) and 9.9 (1.6) days, respectively. Treatment of graft recipients with a neovascularised graft bed with mAb anti-CD4 or anti-T cells, but not with mAb anti-CD8 or with immunosuppressive drugs, resulted in a significant prolongation of graft survival; 75% and 28.5%, respectively, of grafts survived for more than 45 days after grafting. However, none of the treatments were successful in presensitised recipients. CONCLUSIONS: Treatment of high risk recipients with mAb anti-CD4 is more effective in preventing corneal allograft rejection than the treatment with mAb anti-CD8 or the immunosuppressive drugs MMF and CsA. However, the effectiveness of the treatment depends on the recipients' pretransplantation risk type.     

FK-506抑制高危角膜移植免疫排斥反应的研究

目的 :探讨FK -5 0 6抑制高危角膜移植免疫排斥反应临床应用的可行性及有效性。方法 :应用前瞻性评估研究方法 ,将行高危角膜移植术 (全角膜移植术、带巩膜环的全角膜移植术、血管化角膜的角膜移植术及角膜再移植术 ) 5 6例 (5 6只眼 )患者按随机原则进行分组 (投药组及对照组 ) ,投药组 (2 8只眼 )滴用 0 5mg/ml的FK -5 0 6滴眼液联合典必珠滴眼液 ,对照组 (2 8只眼 )滴用 1%CsA滴眼液联合典必殊滴眼液 ;平均随访 8 1个月 ,以术后视功能、植片透明维持时间、植片新生血管、水肿及混浊程度作为临床主要评估指标。结果 :随防期内投药组及对照组角膜移植片免疫排斥反应发生率分别为 63 6%及 95 2 % ,差异有显著性 (χ2 =4 72 ,P <0 0 5 )。用药期间未发现该药有任何毒副作用。结论 :局部应用FK -5 0 6可有效抑制高危角膜移植免疫排斥反应的发生。     

Prolongation of corneal allograft survival by CTLA4-FasL in a murine model

Background To investigate the therapeutic effect of CTLA4-FasL—B7 costimulatory pathway blockage—on graft survival in a murine model of corneal transplantation. Methods Orthotopic penetrating keratoplasty was performed on BALB/c mice. The mice were randomized into four groups: the isograft group, untreated allograft group, cyclosporine A drug delivery system (CsA DDS)-anterior chamber implanted group, and 10 μg/mL CTLA4-FasL-treated group. Allografts were from C57BL/6 mice. Survival time of corneal grafts was evaluated. Immunohistological method and TdT-mediated dUTP Nick End Labeling (TUNEL) were applied for the detection of CD4+ T cells and apoptotic cells in corneal transplants. To assess whether peripheral immune tolerance appeared after the treatment of CTLA4-FasL, CsA DDS-implanted- and CTLA4-FasL-treated BALB/c mice with clear grafts received skin allografts at 4 weeks after keratoplasty, and the status of corneal transplants were observed when skin grafts were rejected. Results Allografts in the CTLA4-FasL group (median survival time [MST] = 106 days, p = 0.0042) and the CsA DDS group (MST = 60 days, p = 0.0037) revealed extending survival time, compared with that in the untreated allograft group (MST = 14 days). There were significantly fewer CD4-positive T cells in both the isograft group and the CsA DDS group. In the untreated allograft group, the number of CD4+ T cells gradually increased from day 1 until the final day of observation (day 21). By contrast, it reached a peak on day 7 and then absolutely reduced in the CTLA4-FasL group. Many apoptotic cells were detected on day 7 in the CTLA4-FasL group, but very few were seen in the other groups. Within 30 days of skin-graft rejection, previously healthy and long-standing corneal grafts became rejected in the CsA DDS group but remained clear in the CTLA4-FasL group. Conclusions CTLA4-FasL can prolong the survival time of corneal allografts in mice, exerting a negative regulation on T-cell activation simultaneously by blocking B7 costimulatory signals and inducing Fas-FasL apoptotic pathway. Due to the adjunctive role of FasL, it also appears to be a potential activity of tolerance induction through T-cell apoptotic pathways.