Renata Ruoco Loureiro

Transplantation of Conjunctival Epithelial Cells Cultivated Ex Vivo in Patients With Total Limbal Stem Cell Deficiency

Purpose: To report the outcomes of transplantation of autologous conjunctival epithelial cells cultivated ex vivo (EVCAU) in patients with total limbal stem cell deficiency (LSCD). Methods: EVCAU were cultivated on denuded human amniotic membrane and transplanted in 12 eyes of 10 patients with total LSCD. We evaluated the improvement in the defined clinical parameters of LSCD (loss of corneal epithelial transparency, superficial corneal neovascularization and epithelial irregularity/recurrent epithelial breakdown), vision acuity, impression cytology, immunocytochemical analysis (CK3/CK19), and the appearance of a regular hexagonal basal layer of cells on corneal confocal microscopy. Histologic and immunohistochemical features were studied in 3 corneal buttons of patients submitted to penetrating keratoplasty after EVCAU. Results: Cultivated conjunctival epithelium formed 4 to 5 layers with the formation of basement membrane–like structures. Immunocytochemical analysis showed positivity for CK3, CK19, MUC5AC, Ki-67, P63, and ABCG2. The improvement of the clinical parameters for this treatment in our cohort was 10 of 12 (83.3%) in a mean follow-up time of 18.5 months (range, 15–26 months), and these eyes showed an improvement in impression cytology, immunocytochemistry, and in vivo confocal analysis. Corneal buttons showed a well-formed epithelium with 5 to 6 layers, with rare cells periodic acid–Schiff+, and positivity for CK3, CK19, P63, connexin 43, and MUC5AC. Conclusion: We demonstrated the preliminary results of transplantation of EVCAU for corneal surface reconstruction in cases with total LSCD. Future studies are needed to further assess the long-term efficacy of this procedure.

Comparison between different biomaterial scaffolds for limbal-derived stem cells growth and enrichment.

Purpose/Aim: Corneal epithelial stem cells have been used for the treatment of total limbal deficiency with corneal conjunctivalization and decreased vision secondary to a variety of ocular surface diseases. We set to compare the ability of different extracellular components in promoting growth and migration of these cells. Materials and Methods: Growth parameters were evaluated, including cell migration and proliferation (by wound healing) and mRNA gene expression (by quantitative RT-PCR). Results: The growth of corneal epithelial cells plated onto different matrix has shown that all treatments were efficient in supporting exponential growth, with a small increase in the puramatrix and collagen I groups when compared with fibrin treatment, which displayed the best doubling time rate and saturation density. The mRNA relative levels for c-myc, a proliferation marker, were considerably higher in the fibrin-coated group. In a smaller extent, the same could be observed for the puramatrix and collagen I groups. The same pattern could be observed for β-1 and α-6-integrin mRNA relative levels. The levels of CD71 mRNA, a LESC negative marker, were decreased in all groups, with a greater decrease in the fibrin group. We also found that the relative mRNA levels of the efflux pump ABCG2 and ▵Np63 transcripts were significantly higher in the fibrin group but not for collagen and puramatrix groups. Moreover, a diminished capacity of wound repair was observed for the uncoated control while the coated biomaterial groups were able to restore the cell-covered surface at some extent. Conclusion: All components tested were effective in promoting growth of corneal epithelial cells and maintenance of stem cell putative markers when compared with the uncoated surface group. Fibrin was far superior than collagen I and puramatrix in promoting survival, growth and migration of these cells.

Human Leukocyte Antigen Class I Genes Associated With Stevens-Johnson Syndrome and Severe Ocular Complications Following Use of Cold Medicine in a Brazilian Population

Importance Describing the association with human leukocyte antigen (HLA) alleles could facilitate the understanding of increased risk factors for development of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients with severe ocular complications (SOCs). Objective To investigate the association between HLA class I genes and cold medicine (CM)–associated SJS/TEN with SOCs. Design, Setting, and Participants This case-control study was conducted between February 8, 2013, and August 29, 2014. Thirty-nine Brazilian patients with CM-SJS/TEN of 74 patients with SJS/TEN with SOCs and 133 healthy Brazilian volunteers were enrolled. Human leukocyte antigen class I genes (HLA-A, HLA-B, and HLA-C) were examined to determine whether there was a genetic predisposition for CM-SJS/TEN with SOC. Patients were interviewed to identify possible etiologic factors. Data analysis was performed from April 14, 2013, to August 29, 2014. Main Outcomes and Measures Genetic predisposition for CM-SJS/TEN with SOCs by analysis of HLA class I genes. Results Of 74 patients included in the analysis, 32 (43%) were male; mean (SD) age was 36.01 [15.42] years. HLA-A*66:01 (odds ratio [OR], 24.0; 95% CI, 2.79-206.0; P < .001), HLA-B*44:03 (OR, 2.71; 95% CI, 1.11-6.65; P = .04), and HLA-C*12:03 (OR, 5.6; 95% CI, 1.67-18.80; P = .006) were associated with Brazilian CM-SJS/TEN with SOCs, and HLA-A*11:01 (OR, 0.074; 95% CI, 0.004-1.26; P = .008), HLA-B*08:01 (OR, 0.15; 95% CI, 0.02-1.15; P = .048), and HLA-B*51:01 (OR, 0.23; 95% CI, 0.05-1.03; P = .045) were inversely associated with Brazilian CM-SJS/TEN with SOCs (39 cases: 19 Pardo and 16 European ancestry; 14 males and 25 females; age, 35.2 [14.4] years; and 133 controls: 66 Pardo and 61 European ancestry; 55 males and 78 females; age, 41.2 [12.9] years). When multiple test correction within the HLA locus, HLA-A*66:01 and HLA-C*12:03 demonstrated associations. When participants were segregated into Pardo and locus is considered, HLA-A*66:01 was associated with CM-SJS/TEN with SOC among individuals of both ethnic groups (Pardo: OR, 12.2; 95% CI, 1.19-125.0; P = .03; and European: OR, 21.2; 95% CI, 0.97-465.0; P = .04). An association was observed only in the European cohort for HLA-B*44:03 (OR, 5.50; 95% CI, 1.47-20.50; P = .01) and HLA-C*12:03 (OR, 8.79; 95% CI, 1.83-42.20; P = .008). Conclusions and Relevance This study suggests that HLA-A*66:01 might be a marker for CM-SJS/TEN with SOCs in Brazilian individuals of Pardo and European ancestry and that HLA-B*44:03 and HLA-C*12:03 might be markers only in those of European ancestry. Moreover, HLA-A*11:01 might be a marker of resistance to CM-SJS/TEN with SOCs.

Comparação entre membrana amniótica com e sem epitélio como substrato para cultura de células epiteliais do limbo ex vivo

PURPOSE: To evaluate the efficacy and ultrastructural aspects of human limbal epithelial cells cultured on amniotic membrane (AM) with and without epithelium. METHODS: Limbal epithelial cell cultures were established from cadaveric cor neo-scleral rim explants derived from 6 different donors. The explants from each donor were placed under 3 different groups: on human preserved AM with epithelium (Group 1), AM deepithelialized with trypsin (Group 2) and control (Group 3). The epithelial cell migration was evaluated under phase contrast microscopy. After 15 days, the amniotic membrane with cells cultures were removed and submitted to scanning and transmission electron microscopy to check for epithelial migration and adhesion. RESULTS: All epithelial cell cultures from the controls grew over the botton of the culture plate wells until reaching confluence. Epithelial cultures grew over all but one denuded amniotic membrane. In the group amniotic membrane with epithelium, epithelial cell growing was observed only in 1 well. CONCLUSIONS: Using this model, denuded amniotic membrane appeared to be the best substrate for epithelial cell migration and adhesion comparing to amniotic membrane with epithelium. Removal of amniotic membrane epithelial seems to be an important step for establishing limbal epithelial cell culture on amniotic membrane.

The effects of riboflavin and ultraviolet light on keratocytes cultured in vitro

PURPOSE To culture quiescent human keratocytes and evaluate the effects of ultraviolet light and riboflavin on human corneal keratocytes in vitro. METHODS Keratocytes were obtained from remaining corneoscleral ring donor corneas previously used in corneal transplant surgeries and cultured in DMEM/F12 with 2% FBS until confluence. Characterization of cultured cells was performed by immunofluorescence analysis for anti-cytokeratin-3, anti-Thy-1, anti-α-smooth muscle actin, and anti-lumican. Immunofluorescence was performed before and after treatment of cultured cells with either ultraviolet light or riboflavin. Corneal stromal cells were covered with collagen (200 µL or 500 µL) and 0.1% riboflavin, and then exposed to ultraviolet light at 370 nm for 30 minutes. After 24 hours, cytotoxicity was determined using MTT colorimetric assays, whereas cell viability was assessed using Hoechst 33342 and propidium iodide. RESULTS Cell cultures achieved confluence in approximately 20 days. Expression of the lumican was high, whereas no expression of CK3, Thy-1, and α-SMA was observed. After crosslinking, MTT colorimetric assays demonstrated a low toxicity rate, whereas Hoechst 33342/propidium iodide staining demonstrated a low rate of apoptosis and necrosis, respectively, in all collagen-treatment groups. CONCLUSION Keratocytes can be successfully cultured in vitro and characterized by immunofluorescence using lumican. MTT colorimetric assays, and Hoechst 33342, and propidium iodide staining demonstrated a higher rate of cell death in cells cultured without collagen, indicating collagen protects keratocytes from the cytotoxic effects of ultraviolet light.