Systemic Immunosuppression for Limbal Allograft and Allogenic Limbal Epithelial Cell Transplantation

Bilateral limbal stem cell deficiency (LSCD) treatment requires the need to obtain allogenic limbal tissue for transplantation. Outcomes of different surgical techniques depend on multiple factors, including the underlying etiology, ocular surface, eyelid status and used surgical intervention. Some of the management options for bilateral LSCD include cadaveric, living related or living non-related conjunctival limbal allograft (CLAL), keratolimbal allograft (KLAL), allogenic cultured limbal epithelial transplantation (CLET) and allogenic simple limbal epithelial transplantation (SLET). Systemic immunosuppressive therapy plays a pivotal role in survival of transplanted tissue. The present review focuses on different systemic immunosuppression protocols for limbal allograft and allogenic limbal epithelial cell transplantation, with specific emphasis on different surgical techniques and their outcomes. We included all reports with details of different systemic immunosuppression protocols for limbal allograft and allogenic limbal epithelial cell transplantation. Oral cyclosporine A at different doses is the most commonly used immunosuppressive agent in limbal allograft and allogenic limbal epithelial cell transplantation. However, different studies using oral mycophenolate mofetil and tacrolimus also reported good results. In conclusion, systemic immunosuppression protocols for limbal allograft and allogenic limbal epithelial cell transplantation are not standardized. Further studies regarding different surgical techniques should assess outcomes and adverse effects of such protocols

Systemic Immunosuppression for Limbal Allograft and Allogenic Limbal Epithelial Cell Transplantation

Bilateral limbal stem cell deficiency (LSCD) treatment requires the need to obtain allogenic limbal tissue for transplantation. Outcomes of different surgical techniques depend on multiple factors, including the underlying etiology, ocular surface, eyelid status and used surgical intervention. Some of the management options for bilateral LSCD include cadaveric, living related or living non-related conjunctival limbal allograft (CLAL), keratolimbal allograft (KLAL), allogenic cultured limbal epithelial transplantation (CLET) and allogenic simple limbal epithelial transplantation (SLET). Systemic immunosuppressive therapy plays a pivotal role in survival of transplanted tissue. The present review focuses on different systemic immunosuppression protocols for limbal allograft and allogenic limbal epithelial cell transplantation, with specific emphasis on different surgical techniques and their outcomes. We included all reports with details of different systemic immunosuppression protocols for limbal allograft and allogenic limbal epithelial cell transplantation. Oral cyclosporine A at different doses is the most commonly used immunosuppressive agent in limbal allograft and allogenic limbal epithelial cell transplantation. However, different studies using oral mycophenolate mofetil and tacrolimus also reported good results. In conclusion, systemic immunosuppression protocols for limbal allograft and allogenic limbal epithelial cell transplantation are not standardized. Further studies regarding different surgical techniques should assess outcomes and adverse effects of such protocols

Ocular Involvement and Blindness Secondary to Linear IgA Dermatosis

A 43-year-old man with linear immunoglobulin A (IgA) dermatosis associated with gluten intolerance presented with progressive vision loss, pain and photosensitivity in both eyes. His visual acuity was light perception (LP) in both eyes. A physical examination revealed bullous, papular lesions with erythematous borders in periocular tissues, limbs, and thorax. Slit-lamp examination showed conjunctival hyperemia, fibrosis, corneal opacification, and vascularization with epithelial defects. Immunofluorescent skin and corneal surface biopsy studies showed linear IgA deposits. The patient was treated with keratolimbal allogenic transplantation and cryopreserved amniotic membrane in the right eye. Regardless of the treatment he persisted with torpid evolution developing retinal and choroidal detachments. After these events he was started on intravenous immune globulin (IVIG) and showed very slight improvement in ocular surface. These types of blistering diseases are rare in the eye. Even when adequate local treatment is given, systemic treatment is mandatory and ocular prognosis can be unsatisfactory

Future Perspectives of Therapeutic, Diagnostic and Prognostic Aptamers in Eye Pathological Angiogenesis

Aptamers are single-stranded DNA or RNA oligonucleotides that are currently used in clinical trials due to their selectivity and specificity to bind small molecules such as proteins, peptides, viral particles, vitamins, metal ions and even whole cells. Aptamers are highly specific to their targets, they are smaller than antibodies and fragment antibodies, they can be easily conjugated to multiple surfaces and ions and controllable post-production modifications can be performed. Aptamers have been therapeutically used for age-related macular degeneration, cancer, thrombosis and inflammatory diseases. The aim of this review is to highlight the therapeutic, diagnostic and prognostic possibilities associated with aptamers, focusing on eye pathological angiogenesis

Carboxy-Terminal Cementum Protein 1-Derived Peptide 4 (cemp1-p4) Promotes Mineralization through wnt/β-catenin Signaling in Human Oral Mucosa Stem Cells

Human cementum protein 1 (CEMP1) is known to induce cementoblast and osteoblast differentiation and alkaline phosphatase (ALP) activity in human periodontal ligament-derived cells in vitro and promotes bone regeneration in vivo. CEMP1′s secondary structure analysis shows that it has a random-coiled structure and is considered an Intrinsic Disordered Protein (IDP). CEMP1′s short peptide sequences mimic the biological capabilities of CEMP1. However, the role and mechanisms of CEMP1′s C-terminal-derived synthetic peptide (CEMP1-p4) in the canonical Wnt/β-catenin signaling pathway are yet to be described. Here we report that CEMP1-p4 promotes proliferation and differentiation of Human Oral Mucosa Stem Cells (HOMSCs) by activating the Wnt/β-catenin pathway. CEMP1-p4 stimulation upregulated the expression of β-catenin and glycogen synthase kinase 3 beta (GSK-3B) and activated the transcription factors TCF1/7 and Lymphoid Enhancer binding Factor 1 (LEF1) at the mRNA and protein levels. We found translocation of β-catenin to the nucleus in CEMP1-p4-treated cultures. The peptide also penetrates the cell membrane and aggregates around the cell nucleus. Analysis of CEMP1-p4 secondary structure revealed that it has a random-coiled structure. Its biological activities included the induction to nucleate hydroxyapatite crystals. In CEMP1-p4-treated HOMSCs, ALP activity and calcium deposits increased. Expression of Osterix (OSX), Runt-related transcription factor 2 (RUNX2), Integrin binding sialoproptein (IBSP) and osteocalcin (OCN) were upregulated. Altogether, these data show that CEMP1-p4 plays a direct role in the differentiation of HOMSCs to a “mineralizing-like” phenotype by activating the β-catenin signaling cascade