bromochloroacetic-acid and Conjunctivitis

It has been hypothesized that the biosynthesis of O-linked glycans on proteins, particularly on the highly O-glycosylated mucins, by the corneal and conjunctival epithelium is necessary for the protection and maintenance of a healthy ocular surface. The initial step in O-glycosylation is the enzymatic addition of N-acetyl galactosamine (GalNAc) to serine and threonine residues by a large family of polypeptide GalNAc-transferases (GalNAc-Ts). The purpose of this study was to determine the cellular distribution of GalNAc-Ts in the normal ocular surface epithelia and to compare their distribution with that in pathologically keratinized conjunctival epithelia.. Five conjunctival biopsy specimens and 5 corneas from normal individuals, and 14 conjunctival specimens from patients with ocular cicatricial pemphigoid (OCP) were used. Based on the histologic characteristics of their epithelia, OCP specimens were divided into two groups: less advanced, nonkeratinized (n = 6), and late-stage, keratinized (n = 8). Five monoclonal antibodies raised against the GalNAc-T1, -T2, -T3, -T4, and -T6 isoenzymes, were used for immunofluorescence microscopic localization according to standard protocols.. Immunohistochemical studies revealed the presence of GalNAc-T2, -T3, and -T4 isoforms within the stratified epithelium of the cornea and the conjunctiva. The GalNAc-T4 isoenzyme was found in the apical cell layers, whereas GalNAc-T2 was found in the supranuclear region of the basal cell layers of both cornea and conjunctiva. GalNAc-T3 was distributed throughout the entire ocular surface epithelium, whereas GalNAc-T1 was found in scattered cells in conjunctiva only. Binding of antibody to GalNAc-T6 was restricted exclusively to conjunctival goblet cells. There were distinct alterations in expression patterns of GalNAc-T2, -T6, and -T1 in nonkeratinized OCP epithelia compared with normal epithelia. Both GalNAc-T2 and -T6 were expressed in the apical stratified epithelia, and T1 was detected in all cell layers in five of six biopsy specimens. By comparison with nonkeratinized OCP epithelia, a marked reduction in the binding of GalNAc-T antibody was observed in the late-stage keratinized conjunctival epithelia of patients with OCP. In all samples, apical GalNAc-T2 was absent, and GalNAc-T6 was entirely absent. Only one of eight samples was positive for GalNAc-T1.. The presence of GalNAc-T isoenzymes in the human corneal and conjunctival epithelia is cell-layer and cell-type specific. The increased distribution of GalNAc-Ts observed in early stages of the keratinization process in patients with OCP suggests a compensatory attempt of the ocular surface epithelium to synthesize mucin-type O-glycans to maintain a wet-surface phenotype. This early increase in isoenzymes in nonkeratinized OCP epithelia is reduced as keratinization proceeds in the disease.

Topics: Aged; Aged, 80 and over; Antibodies, Monoclonal; Conjunctiva; Conjunctivitis; Cornea; Epithelial Cells; Female; Fluorescent Antibody Technique, Indirect; Goblet Cells; Humans; Isoenzymes; Keratins; Male; Microscopy, Fluorescence; Middle Aged; N-Acetylgalactosaminyltransferases; Pemphigoid, Benign Mucous Membrane

Cicatricial conjunctivitis may be a sequel to systemic disorders (eg, Stevens-Johnson syndrome, cicatricial pemphigoid) or local disorders such as chemical burns. The cicatrisation is often associated with corneal epithelial changes that cause visual loss. These have been attributed to encroachment of the conjunctival epithelium over the cornea. However, the epithelial anomalies are poorly understood. We investigated the corneal epithelial changes in cicatricial conjunctivitis with an immunohistochemical study of intermediate filaments in normal and pathological specimens. Our results show that the normal corneal epithelium is immunoreactive for cytokeratin 3 (CK 3) but not cytokeratin 19 (CK 19), whereas normal conjunctival epithelium is CK 3 negative and CK 19 positive. Conjunctiva artificially transposed over the cornea (after therapeutic conjunctival flap reconstruction) retained the normal pattern of conjunctival cytokeratin expression (CK 3 negative, CK 19 positive). Conversely, the entire corneal epithelium exhibited the normal cytokeratin pattern (CK 3 positive, CK 19 negative) in 82% of Stevens-Johnson, 80% of cicatricial pemphigoid, and 69% of chemical burns specimens. The findings suggest that conjunctival encroachment is not responsible for the changes at the corneal surface in cicatricial conjunctivitis and that the abnormal corneal epithelium is derived from native corneal cells in these diseases.

Topics: Adult; Aged; Biomarkers; Conjunctivitis; Cornea; Epithelium; Humans; Intermediate Filaments; Keratins; Middle Aged; Pemphigoid, Benign Mucous Membrane; Staining and Labeling; Stevens-Johnson Syndrome; Surgical Flaps

A patient presented with central corneal scarring and neovascularization associated with elevated deposits that were shown to be keratin and calcium. Giant papillary conjunctivitis (GPC) was noted at a corresponding location in the palpebral conjunctiva. The lid reaction resolved after the elevated corneal deposits were debrided. A rigid gas-permeable contact lens was then fitted for visual rehabilitation. Either foreign bodies or elevated corneal deposits may cause GPC.

Topics: Adult; Calcium; Conjunctivitis; Contact Lenses; Cornea; Corneal Diseases; Giant Cells; Humans; Keratins; Male; Neovascularization, Pathologic; Visual Acuity

We report four cases of corneoconjunctival keratinization that were successfully treated with topical retinoic acid ointment. In two cases keratinization was due to squamous metaplasia and in two others it was secondary to intraepithelial corneoconjunctival neoplasia. Treatment reversed severe keratinization in a case of drug-induced pseudopemphigoid and stabilized the disease in one of the two affected eyes without additional treatment. In a case of ocular cicatricial pemphigoid, retinoic acid was useful as an adjuvant therapy to immunosuppression, by reversing keratinization of the conjunctiva. In two cases of corneoconjunctival neoplasia, lesions regressed markedly. Long-term treatment was well tolerated in three patients. Our findings suggest that retinoic acid ointment is effective in treating severe squamous metaplasia in cicatrizing diseases of the conjunctiva. Our findings indicate further that retinoic acid seems to inhibit growth of corneoconjunctival neoplasias and thus might be useful complementary therapy in this situation.

Topics: Administration, Topical; Aged; Aged, 80 and over; Conjunctiva; Conjunctival Diseases; Conjunctival Neoplasms; Conjunctivitis; Cornea; Corneal Diseases; Epithelium; Female; Humans; Keratins; Male; Metaplasia; Tretinoin