Chie Sotozono

Cultivated corneal epithelial stem cell transplantation in ocular surface disorders

PURPOSE To investigate the outcome of cultivated corneal epithelial transplantation for severe stem cell deficiencies using denuded amniotic membrane (AM) as a carrier. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Thirteen eyes of 11 patients were studied. These consisted of five eyes with acute Stevens-Johnson syndrome (SJS), two with chronic SJS, one with an acute chemical injury, two with chronic chemical injuries, two with ocular cicatricial pemphigoid, and one with drug-induced pseudopemphigoid. All of these eyes had total stem cell deficiencies. MAIN OUTCOME MEASURES Adaptation of the cultivated corneal epithelium onto the host corneal surface was confirmed 48 hours after surgery. The reconstruction of the ocular surface and visual acuity were measured. METHODS Corneal limbal epithelium from donor corneas was cultivated for 4 weeks on a denuded AM carrier, with 3T3 fibroblast coculture and air lifting. The cultivated corneal epithelium showed four to five layers of stratification and was well differentiated. After conjunctival tissue removal from the cornea up to 3 mm outside the limbus and subconjunctival tissue treatment with 0.04% mitomycin C, cultivated allocorneal epithelium, including the AM carrier, was transplanted onto the corneal surface up to the limbus. Lamellar keratoplasty, using preserved donor graft without epithelium, was performed simultaneously for five chronic-phase patients showing corneal stromal scarring. Systemic immunosuppression was used to prevent allograft rejection. RESULTS In all 13 eyes, the entire corneal surface, on which cultivated allocorneal epithelium had been placed, was free from epithelial defects 48 hours after surgery, indicating complete survival of the transplanted corneal epithelium. Visual acuity improved in all eyes after surgery, and 10 of the 13 eyes were restored to good vision (postoperative visual acuity improved two or more lines) 6 months after the operation. During the follow-up period (mean +/- standard deviation, 11.2 +/- 1.3 months), the corneal surfaces were clear, although three eyes experienced epithelial rejection. CONCLUSIONS Cultivated corneal epithelial transplantation using denuded AM as a carrier can be used for severe stem cell deficiencies.

Growth factors: importance in wound healing and maintenance of transparency of the cornea

The mechanism of corneal wound healing has not been clarified yet. However, evidence has accumulated that various kinds of growth factor such as epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor (TGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF) and insulin-like growth factor (IGF) play a key role in corneal wound healing. For example, these growth factors are expressed in the corneal epithelial cells, keratocytes and endothelial cells, and their receptors are expressed in the corneal cells. Furthermore, these growth factors promote the proliferation of corneal cells and induce the migration of corneal cells. In addition to the growth factors, inflammatory cytokines such as interleukin (IL)-1, IL-6 and TNF-alpha are involved in corneal wound healing. These cytokines are expressed in the normal and inflammatory cornea after infections, alkaliburn, etc. where they control the growth of corneal cells and induce the migration of corneal cells. Thus, a number of growth factors and cytokines function in the regulation of corneal cell proliferation and in the maintenance of corneal transparency.

HLA-B locus in Japanese patients with anti-epileptics and allopurinol-related Stevens-Johnson syndrome and toxic epidermal necrolysis.

INTRODUCTION Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening severe cutaneous adverse reactions. Recently, strong associations of HLA-B*1502 and HLA-B*5801 with carbamazepine- and allopurinol-induced severe cutaneous adverse reactions were found in Han Chinese patients, respectively, but ethnic differences in the associations have been reported. The objective of this study is to clarify the involvement of HLA-B*1502 and HLA-B*5801 in Japanese SJS/TEN patients. METHODS HLA-B genotyping was performed on 58 Japanese SJS/TEN patients between July 2006 and April 2008 from multicenters in Japan. RESULTS There were no HLA-B*1502 carriers among 58 SJS/TEN patients. This patient group included seven carbamazepine-related and 11 aromatic anti-epileptic agent-related SJS/TEN patients. In addition, there were five HLA-B*5801 carriers, which included four allopurinol-related SJS/TEN patients. CONCLUSION While HLA-B*1502 is unlikely to be associated with carbamazepine-related or aromatic anti-epileptic agent-related SJS/TEN, HLA-B*5801 was significantly associated with allopurinol-related SJS/TEN in Japanese.

Transplantation of cultivated autologous oral mucosal epithelial cells in patients with severe ocular surface disorders

Background/aims: To determine outcomes of transplants of cultivated autologous oral epithelial cells in patients with severe ocular surface disorders. Methods: The eyes (n = 6) of four patients with Stevens-Johnson syndrome (three eyes) or chemical burns (three eyes) were studied. Autologous oral epithelial cells, grown for 2–3 weeks on a denuded amniotic membrane carrier in the presence of 3T3 fibroblasts, were air lifted. The resultant sheet was transplanted onto the damaged eye, and acceptance of the sheet by the corneal surface was confirmed 48 hours after surgery. The success of ocular surface reconstruction, graft survival, changes in visual acuity, and postoperative complications were assessed and the quality of the cultivated oral epithelial sheet was evaluated histologically. Results: At 48 hours after transplant, the entire corneal surface of all six eyes was free of epithelial defects indicating complete survival of the transplanted oral epithelium. Visual acuity was improved in all eyes. During follow up (mean 13.8 (SD 2.9) months), the corneal surface remained stable, although all eyes manifested mild peripheral neovascularisation. Conclusions: Autologous oral epithelial cells grown on denuded amniotic membrane can be transplanted to treat severe ocular surface disorders.

Characteristics of the human ocular surface epithelium.

An appreciation of the biological characteristics of the human ocular surface epithelium affords us a great insight into the physiology of the human ocular surface in health and disease. Here, we review five important aspects of the human ocular surface epithelium. First, we recognize the discovery of corneal epithelial stem cells, and note how the palisades of Vogt have been suggested as a clinical marker of their presence. Second, we introduce the concept of the gene expression profile of the ocular surface epithelium as arrived at using a new strategy for the systematic analysis of active genes. We also provide a summary of several genes abundantly or uniquely expressed in the human corneal epithelium, namely clusterin, keratin 3, keratin 12, aldehyde dehydrogenase 3 (ALDH3), troponin-I fast-twitch isoform, ssig-h3, cathepsin L2 (cathepsin V), uroplakin Ib, and Ca(2+)-activated chloride channel. Genes related to limbal and conjunctival epithelia are also described. Third, we touch upon the genetic abnormalities thought to be involved with epithelial dysfunction in Meesmanns dystrophy, gelatinous drop-like corneal dystrophy, and the ssig-h3-mutated corneal dystrophies. Fourth, we provide an update regarding the current state of knowledge of the role of cytokines, growth factors and apoptosis in relation to ocular surface homeostasis and tissue reconstruction; the main factors being epidermal growth factor (EGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), transforming growth factor-ss (TGF-ss), and some inflammatory cytokines. Fifth, corneal epithelial barrier function and dysfunction as measured by fluorophotometry is remarked upon, with an explanation of the FL-500 fluorophotometer and its ability to detect corneal epithelial dysfunction at a subclinical level. The research described in this review has undoubtedly generated a complete understanding of corneal epithelial pathophysiology-an understanding that, directly or indirectly, has helped advance the development of new therapeutic modalities for ocular surface reconstruction.

HLA-B*1511 is a risk factor for carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Japanese patients

Stevens‐Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life‐threatening severe cutaneous adverse reactions. Recently, strong associations of HLA‐B*1502 with carbamazepine‐induced SJS/TEN have been found in Han Chinese patients. These associations have been confirmed in several Asian populations, excluding Japanese. SJS patients carrying HLA‐B*1508, HLA‐B*1511, or HLA‐B*1521, which are members of the HLA‐B75 type along with HLA‐B*1502, were detected in studies in India and Thailand. In the current study, we genotyped the HLA‐B locus from 14 Japanese typical and atypical SJS/TEN patients in whom carbamazepine was considered to be involved in the onset of adverse reactions. Although there were no HLA‐B*1502 carriers, four patients had HLA‐B*1511. Our data suggest that HLA‐B*1511, a member of HLA‐B75, is a risk factor for carbamazepine‐induced SJS/TEN in Japanese.

Dissemination of Methicillin-Resistant Staphylococci among Healthy Japanese Children

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA), regarded as a tenacious pathogen in the hospital, has recently become increasingly prevalent as a community pathogen. We evaluated the prevalence and characteristics of methicillin-resistant staphylococci in the Japanese community by testing nasal samples of 818 children of five day care centers and two kindergartens in three districts. We found that methicillin-resistant staphylococci are already prevalent among healthy children. Among 818 children, 35 children (4.3%) carried MRSA and 231 children (28.2%) carried methicillin-resistant coagulase-negative staphylococci (MRC-NS). The types of staphylococcal cassette chromosome mec (SCCmec) found among 44 MRSA isolates were as follows: type IIa, 11 isolates; type IIb, 19 isolates; and type IV, 14 isolates. The type IIb SCCmec element was a new SCCmec element found in this study. Eleven (25%) strains which belonged to clonal complex 5 (CC5) carried type IIa SCCmec, and they produced type 2 coagulase and toxic shock syndrome toxin 1. They were indistinguishable from health care-associated MRSA (H-MRSA) strains in Japan, represented by strain N315. On the other hand, 33 (75%) strains, most of which belonged to CC78 or CC91, carried small SCCmec elements, such as type IIb or type IV, and they produced type 1 or type 3 coagulase and exfoliative toxin. The data indicated that MRSA clones distinct from H-MRSA have disseminated in healthy children. The fact that MRC-NS strains were prevalent in the community suggested that they might serve as a reservoir for the SCCmec element carried by MRSA strains disseminated in the community.

Immunosuppressive properties of human amniotic membrane for mixed lymphocyte reaction

The combination of allograft limbal transplantation (ALT) and amniotic membrane transplantation (AMT) has been applied in the treatment of severe ocular surface diseases. The beneficial effect of this combination has been thought to result from possible immunosuppressive ability of amniotic membrane (AM). However, the mechanisms of any such ability remain unknown. In this study, we investigated whether human AM has the ability to suppress allo‐reactive T cell responses in vitro. For mixed lymphocyte reaction (MLR), lymphocytes isolated from lymph nodes of C57BL/6 mice (Mls1b, Vβ6+) were cultured with irradiated splenocytes from DBA/2 mice (Mls1a, Vβ6−) with or without human AM. For carboxyfluorescein diacetate succinimidyl ester (CFSE) experiments, responder lymph node cells were labelled with a stable intracellular fluorescent dye and cultured with irradiated stimulator cells. The ratio of responder Vβ6+ T cells was then determined by FACS analysis, and the division profiles of responder Vβ6+ T cells were analysed by CFSE content. Furthermore, Th1 and Th2 cytokine synthesis by allo‐reactive T cells in MLR culture supernatants was determined by enzyme‐linked immunosorbent assay (ELISA). Addition of AM to the MLR culture resulted in the significant inhibition of thymidine incorporation compared with control culture lacking AM. The population of responder CD4+Vβ6+ T cells was significantly reduced in the AM‐treated culture in comparison to control. CFSE analysis revealed less division and lower proliferation of responder CD4+Vβ6+ T cells in cultures with AM than without. In addition, allo‐rective T cell synthesis of both Th1 (IL‐2 and IFNγ) and Th2 (IL‐6 and IL‐10) type cytokine was significantly decreased in the presence of AM. These results indicate that human AM has the ability to suppress allo‐reactive T cells in vitro. This inhibitory effect likely contributes to the success of the ALT‐AMT combination.

Successful regrafting of cultivated corneal epithelium using amniotic membrane as a carrier in severe ocular surface disease

Purpose. Our group performed cultivated allogeneic corneal epithelial transplantation in 13 eyes from 11 patients with severe ocular surface disorders. After the clinical application of this new surgical treatment, some patients experienced epithelial and subepithelial opacities. We applied our procedure again in these patients to achieve successful ocular surface reconstruction. Methods. The corneal limbal epithelial cells from donor corneas were cultivated for 4 weeks on denuded amniotic membrane (AM) carrier, with 3T3 fibroblast coculture and airlifting. The study subjects consisted of 3 patients. At 3 and 12 months after the first operation, the failed epithelial graft with AM was replaced with new allogeneic corneal epithelium cultivated on AM. Results. At 48 hours after transplantation, the corneal surfaces of the 3 eyes were clear and smooth; the entire corneal surfaces were evenly covered with the transplanted cultivated corneal epithelium, which did not stain with fluorescein. The ocular surface epithelia of these patients are all stable without epithelial defects. Conclusions. We have shown that, in cases where the initially transplanted cultivated epithelium becomes opaque, it is possible to repeat the transplantation process with new cultivated epithelium on AM.

Diagnosis and Treatment of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis with Ocular Complications

PURPOSE To present a detailed clarification of the symptoms at disease onset of Stevens-Johnson syndrome (SJS) and its more severe variant, toxic epidermal necrolysis (TEN), with ocular complications and to clarify the relationship between topical steroid use and visual prognosis. DESIGN Cross-sectional study. PARTICIPANTS Ninety-four patients with SJS and TEN with ocular complications. METHODS A structured interview, examination of the patient medical records, or both addressing clinical manifestations at disease onset were conducted for 94 patients seen at Kyoto Prefectural University of Medicine. Any topical steroid use during the first week at the acute stage also was investigated. MAIN OUTCOME MEASURES The incidence and the details of prodromal symptoms and the mucosal involvements and the relationship between topical steroid use and visual outcomes. RESULTS Common cold-like symptoms (general malaise, fever, sore throat, etc.) preceded skin eruptions in 75 cases, and extremely high fever accompanied disease onset in 86 cases. Acute conjunctivitis and oral and nail involvements were reported in all patients who remembered the details. Acute conjunctivitis occurred before the skin eruptions in 42 patients and simultaneously in 21 patients, whereas only 1 patient reported posteruption conjunctivitis. Visual outcomes were significantly better in the group receiving topical steroids compared with those of the no-treatment group (P<0.00001). CONCLUSIONS Acute conjunctivitis occurring before or simultaneously with skin eruptions accompanied by extremely high fever and oral and nail involvement indicate the initiation of SJS or TEN. Topical steroid treatment from disease onset seems to be important for the improvement of visual prognosis.