Ocular Pemphigus

Limbal Stem Cell Deficiency After Glaucoma Surgery

PURPOSE

To characterize the clinical presentation of limbal stem cell deficiency (LSCD) associated with glaucoma surgeries.

METHODS

This is a retrospective cross-sectional study of patients with LSCD and glaucoma who presented to the Stein Eye Institute at the University of California, Los Angeles, between 2009 and 2018. Patients who underwent trabeculectomy and/or aqueous shunt surgery were included. The severity of LSCD was staged using global consensus guidelines and a clinical scoring system, and basal epithelial cell density was measured by in vivo confocal microscopy. Anatomic locations of glaucoma and non-glaucoma surgeries, locations of LSCD, and severity of LSCD were compared.

RESULTS

Fifty-one eyes of 41 patients with LSCD associated with glaucoma surgery were included in this study. LSCD in these patients uniquely featured sectoral replacement of corneal epithelium by conjunctival epithelium, without corneal neovascularization or pannus. The sites of glaucoma surgery strongly correlated with the locations of LSCD (P = 0.002). There was a trend toward increased severity of LSCD in eyes with 2 or more glaucoma surgeries as compared to eyes with 1 glaucoma surgery, although the difference did not reach statistical significance (P = 0.3). Use of topical glaucoma medications correlated with LSCD severity, while the impact of antimetabolites did not reach statistical significance. The location of glaucoma drainage surgery is correlated with the location of LSCD.

CONCLUSIONS

LSCD associated with glaucoma surgery has clinical features distinct from LSCD resulting from other etiologies. Further study is required to delineate the full impact of glaucoma surgery on limbal stem cell function and survival.

Ocular cicatricial pemphigoid: pathogenesis, diagnosis and treatment

Understanding of ocular cicatricial pemphigoid (OCP) has changed dramatically over the last three decades. Progress in basic science research in mucous membrane pemphigoid has been instrumental in outlining the key immune processes that participate in the autoimmune response. Immunomodulatory therapy has provided an avenue for preserving vision and preventing potentially fatal consequences of systemic pemphigoid. In this chapter we focus attention on the immunologic basis for disease and treatment strategies. We propose an algorithmic approach to diagnosis and management of OCP.

Differences in the anti-basement membrane zone antibodies in ocular and pseudo-ocular cicatricial pemphigoid

PURPOSE

Ocular cicatricial pemphigoid (OCP) is a chronic autoimmune cicatrizing disease which affects the conjunctiva and other squamous epithelium, resulting in a scarring process. A similar process, limited only to the conjunctiva, observed in some patients using eye drops for the treatment of glaucoma, is called pseudo-ocular cicatricial pemphigoid (P-OCP). Immunofluorescence studies demonstrate deposition of immunoglobulins and complement components in the basement membrane zone (BMZ) of the conjunctiva and an anti-basement membrane zone antibody in the serum of patients. A striking association between OCP and MHC class II gene DQB1*0301 has been observed. The purpose of this study was to determine some of the differences in the binding of OCP and P-OCP sera to different lysate in an immunoblot assay, in an attempt to partially characterize the OCP and P-OCP antigens. Furthermore, we wanted to determine if the MHC class II gene association of P-OCP is similar to that of OCP.

METHODS

We studied sera from 11 patients with active ocular cicatricial pemphigoid and seven patients with pseudo-ocular cicatricial pemphigoid and controls. Indirect immunofluorescence (IIF) studies were done using monkey esophagus and salt split normal human skin as substrate. A sensitive immunoblot assay (IBA) was developed using normal human epidermis, dermis and conjunctiva as substrate. Typing for MHC class II genes was performed on eight pseudo-ocular cicatricial pemphigoid patients by dot-blot analysis and compared to 38 matched controls.

RESULTS

Weak staining of the basement membrane zone was observed in nine of ten ocular cicatricial pemphigoid sera and five of seven pseudo-ocular cicatricial pemphigoid sera in the IIF assay using monkey esophagus. Using salt split human skin as substrate, ten of eleven ocular cicatricial pemphigoid sera demonstrated low titer weak binding to the epidermal side of the split. No consistent pattern of staining was seen with pseudo-ocular cicatricial pemphigoid sera. Ten of the 11 ocular cicatricial pemphigoid sera demonstrated binding to 230, 205, 160 and 85 kDa proteins in the IBA using normal human epidermis and conjunctiva lysates. When the lysates were first reacted with BP sera and then immunoblotted with ocular cicatricial pemphigoid sera, the 230, 160, and 86 kDa bands disappeared, and only the 205 kDa band persisted. The sera of five of seven pseudo-ocular cicatricial pemphigoid patients bound to 290, 230, 205, 180, 97, and 85 kDa proteins in the epidermis and conjunctiva. However, the 230, 205, 180, and 85 kDa proteins are depleted when the lysates are first reacted with BP and ocular cicatricial pemphigoid sera. In the dermal lysate, the pseudo-ocular cicatricial pemphigoid sera recognize 400, 290, 150 and 45 kDa proteins. None of these are absorbed by BP, ocular cicatricial pemphigoid or pemphigus vulgaris or epidermolysis bullosa acquisita sera. The 290 kDa proteins identified in the dermis and epidermis are distinct from each other. No binding was seen with control sera with the 3 lysates. Statistically, dot-blot analysis did not demonstrate a significant increase in the frequency of the MHC DQB1*0301 gene.

CONCLUSIONS

Patients with ocular cicatricial pemphigoid and pseudo-ocular cicatricial pemphigoid produce several autoantibodies. However, there are similarities and differences between them. The MHC class II genes associated with pseudo-ocular cicatricial pemphigoid are different from those with ocular cicatricial pemphigoid. This provides a new model system to study the immune abnormalities in idiopathic and drug-related organ specific autoimmunity.

Detection and partial characterization of ocular cicatricial pemphigoid antigens on COLO and SCaBER tumor cell lines

Ocular cicatricial pemphigoid (OCP) is a chronic autoimmune inflammatory disease which affects the conjunctiva and other squamous epithelial mucous membranes resulting in a scarring process. It is characterized by the deposition of an anti-basement membrane zone (BMZ) antibody in vivo. Sera from 11 patients with active OCP were studied. Using monkey esophagus and normal skin as substrate, weak staining of the BMZ was observed in conventional indirect immunofluorescence (IIF) assay. Using salt split human skin as substrate, the OCP sera demonstrated binding to the epidermal side of the split, in low titers with weak staining. Ten of the 11 sera were positive on an immunoblot assay using COLO and SCaBER tumor cell lysates demonstrating 230, 205, 160, and 85 kD proteins. Sera from six bullous pemphigoid (BP) patients, with only cutaneous involvement and high titer of anti-BMZ antibody, as detected by IIF, also bound to 230, 160, and 85 kD proteins on both lysates in comigration experiments. Serum from five normal individuals and two patients each with severe atopic conjunctival disease, erythema multiforme with chronic conjunctivitis and systemic lupus erythematosus (SLE), did not demonstrate those bands. When the two lysates were first absorbed with BP sera and then the same lysates were immunoblotted with OCP sera, in all ten OCP sera the 230, 160, and 85 kD bands were eliminated and only a single 205 kD band was uniformly present. These results indicate that OCP sera recognize peptide(s) present in 230, 205 and 160 kD proteins in lysates from COLO and SCaBER tumor cells. These proteins contain the immunodominant region of the BMZ molecule(s) in which the OCP antigen(s) reside. The OCP antigen(s) appears to be distinct from the BP antigen(s).

Cicatricial pemphigoid

Cicatricial pemphigoid is a subepidermal blistering disease that involves the mucous membranes and the skin. The oral cavity and the eye are most frequently involved. The clinical course is of long duration, and often there is significant scarring that can have devastating sequelae. The majority of the patients are elderly. The disease is characterized by the in vivo deposition of an anti-basement membrane zone antibody. The anti-basement membrane zone antibody cannot be detected in the circulation by routine laboratory techniques. The pathogenesis is poorly understood, and the cause is not known. Cicatricial pemphigoid may remain localized to the oral cavity or the eye or the skin (Brunsting-Perry variety), or it may be generalized. It rarely occurs in children, and it may be drug induced. Efforts must be made to differentiate cicatricial pemphigoid from bullous pemphigoid, epidermolysis bullosa acquisita, linear IgA bullous disease, and other vesiculobullous disease. Early recognition and treatment can improve the prognosis and avoid surgical intervention. Topical therapy is beneficial and expedites healing. Intralesional corticosteroids are effective and can help reduce the dose of systemic steroids. Most patients require systemic corticosteroid therapy. Dapsone is also useful in treating cicatricial pemphigoid, especially in patients in whom systemic steroids are ineffective or in whom they have to be discontinued because of side effects. Immunosuppressive agents (azathioprine or cyclosphosphamide) are indicated in patients with progressive disease. Occasionally both drugs may be needed.

Cicatricial pemphigoid and erythema multiforme

Cicatricial pemphigoid (CP) and erythema multiforme (EM) are bullous diseases that involve the skin and mucous membranes including the conjunctiva. Of all the bullous diseases, CP and EM not only involve the conjunctiva most frequently but also cause the most severe conjunctival disease. A chronic, progressive disease, CP is characterized by shrinkage of the conjunctiva, symblepharon, entropion, trichiasis, dry eye, and finally reduced vision from corneal opacification. It is primarily a disease of the elderly that affects more women than men and is characterized by blisters or bullae in a subepithelial location and immunoglobulins and complement bound to the basement membrane zone of skin and mucous membranes including the conjunctiva. Circulating antibodies to the basement membrane zone can be demonstrated occasionally. Treatment includes artificial tears, topical antibiotics, correction of entropion and trichiasis, therapeutic soft contact lenses, and systemic immunosuppressive therapy including corticosteroids. An acute, generally self-limited, inflammatory disorder of the skin and mucous membranes, EM occurs primarily in young, healthy individuals. The most frequent precipitating factors are (1) drugs and (2) infections caused by Mycoplasma pneumoniae and herpes simplex. Conjunctival involvement ranges from a mild catarrhal conjunctivitis which terminates without sequelae to membranous conjunctivitis which may heal leaving scarring, symblepharon, and even ankyloblepharon. Histopathologic findings include subepithelial bullae and perivascular mononuclear cell infiltrates. Patients with EM have circulating immune complexes and immunoreactant deposition in the blood vessel walls of the dermis. After the acute episode has subsided, they may require artificial tears, topical antibiotics, correction of entropion and trichiasis, therapeutic soft contact lenses, tarsorrhaphy, and mucous membrane grafts.

Ocular cicatricial pemphigoid

The characteristic feature of ocular cicatricial pemphigoid (OCP) is progressive shrinkage of the conjunctiva. In our series of 78 patients with OCP, 21% had cutaneous involvement and 50% had involvement of the oral mucosa. Immunoglobulins and the third component of complement are found bound to the conjuctival epithelium and basement membrane of patients with OCP. Circulating antibodies which bind to the conjunctival and corneal epithelium but not to the conjunctival basement membrane have also been demonstrated. OCP is associated with an increased prevalence of HLA-B12. The lids and conjunctiva of patients with OCP demonstrate an increased incidence of potential pathogens when compared with age- and sex-matched controls. When followed for a period averaging 22 months, the majority of patients not treated with systemic immunosuppressives or topical corticosteroids progress. However, OCP has a variable course because there were patients in all stages who did not progress. The acute manifestations of OCP may cause rapid shrinkage of the conjunctiva and may be suppressed systemic corticosteroids.

The acute manifestations of ocular cicatricial pemphigoid: diagnosis and treatment

Seven patients with ocular cicatricial pemphigoid displayed acute inflammatory activity that could not be attributed to secondary bacterial infections, trichiasis, or lagophthalmos secondary to symblepharon. This acute inflammatory activity was manifested either as a localized conjunctival mound that was ulcerated and intensely hyperemic or as diffuse and intense conjunctival hyperemia and chemosis. Acute disease activity developed shortly after conjunctival biopsy in three patients and appeared spontaneously in the other four patients. Conjunctival biopsy specmens disclosed a heavy infiltrate of polymorphonuclear leucocytes within and beneath the conjunctival epithelium in addition to the chronic inflammatory cells typically found in this condition. The acute manifestations of ocular cicatricial pemphigoid cause rapid shrinkage and scarring of the conjunctiva. Systemic corticosteroids suppressed the acute disease activity and prevented additional scarring in all five patients treated.

Modern treatment of severe "shrinkage of the conjunctiva"

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