Subunit-Specific Reactivity of Autoantibodies Against Laminin-332 Reveals Direct Inflammatory Mechanisms on Keratinocytes

Laminin-332 pemphigoid is a rare and severe autoimmune blistering disease, caused by IgG autoantibodies targeting laminin-332 in the dermal-epidermal basement zone. Laminin-332 pemphigoid is characterized by variable inflammatory infiltrate and the predominance of non-complement-fixing antibodies. Given these findings, we hypothesized that IgG autoantibodies to laminin-332 directly resulted in keratinocyte expression of inflammatory factors. We performed RNA-seq on primary human keratinocytes treated with IgG from patients with laminin-332 pemphigoid. Genes for numerous cytokines and chemokines were upregulated, including CSF2, CSF3, CXCL1, CXCL5, CXCL3, CXCL8, CXCL10, CXCL1, IL6, IL7, IL15, IL23, IL32, IL37, TGFB2 as well as metalloproteases. Considering the pro-inflammatory and proteolytic effect of autoantibodies from patients with laminin-332 pemphigoid identified in our initial experiment, we next questioned whether the reactivity against specific laminin subunits dictates the inflammatory and proteolytic keratinocyte response. Then, we treated keratinocytes with IgG from a separate cohort of patients with reactivity against individual subunits of laminin-332. We identified upregulation of IL-1α, IL-6, IL-8, CXCL1, MMP9, TSLP, and GM-CSF at the protein level, most notably in keratinocytes treated with IgG from laminin β3-reactive patients. We for the first time demonstrated a pro-inflammatory response, similar to that described in keratinocytes treated with IgG autoantibodies from patients with bullous pemphigoid, providing novel insight into the pathogenesis of laminin-332 pemphigoid and laminin-332 biology.

The direct binding of collagen XVII and collagen IV is disrupted by pemphigoid autoantibodies

The basement membrane zone (BMZ) is framed by hemidesmosomes and extracellular matrix (ECM) including collagen IV (COL4). Hemidesmosomes are multiprotein complexes that include collagen XVII (COL17). BMZ proteins can be targeted in autoimmune subepidermal blistering diseases, e.g., pemphigoid targeting COL17. The blistering mechanisms in pemphigoid have not been fully elucidated, especially in mucous membrane pemphigoid (MMP), which mainly affects the mucosa. In this study, we showed that oral lesions in pemphigoid may be attributed to the inhibition of protein-protein interactions by autoantibodies. Using immunoprecipitation, we revealed that COL17 directly binds to COL4 in normal human keratinocytes and normal human oral keratinocytes. In particular, the C-terminus of COL17 is binding site to COL4 in oral keratinocytes. The precise COL4-binding region on COL17 was determined by protein-protein binding assay to be from amino acid Gly1175 to Asp1340 on the C-terminus. MMP-IgG or mAb recognizing the C-terminus hindered the interaction of COL17 with COL4 in oral keratinocytes. Furthermore, keratinocyte adhesion strength to COL4-coated plates was significantly reduced by the treatment of mAb against the C-terminus. In addition, the inflammatory infiltrates around perilesions were significantly less in MMP compared to BP. These results indicate that pemphigoid IgG targeting the C-terminus plays a pathogenic role in blister formation in the oral mucosa to inhibit protein interactions with less inflammation.

Molecular diagnosis of anti-laminin 332 (epiligrin) mucous membrane pemphigoid

BACKGROUND

Mucous membrane pemphigoid is a group of chronic subepithelial autoimmune blistering diseases that mainly affect mucous membranes. Laminin 332-specific autoantibodies are present in approximately 1/3 of the patients, being associated with an increased risk of malignancy. Because of the severe complications, an early recognition of the disease allowing a timely therapy is essential. The gold standard methods for detection of laminin 332-specific autoantibodies, including the immunoprecipitation and immunoblotting are non-quantitative, laborious and restricted to a few specialized laboratories worldwide. In addition, the use of radioimmunoassays, although highly sensitive and specific, are laborious, expensive and tightly regulated. Therefore, there is a stringent need for a quantitative immunoassay for the routine detection of laminin 332-specific autoantibodies more broadly available to diagnostic laboratories. The aim of this study was to compare different antigenic substrates, including native, recombinant laminin 332 and laminin 332-rich keratinocyte extracellular matrix, for development of an ELISA to detect autoantibodies in mucous membrane pemphigoid.

RESULTS

Using a relatively large number of sera from MMP patients with well-characterized autoantibody reactivity we show the suitability of ELISA systems using laminin 332 preparations as adjunct diagnostic tools in MMP. While glycosylation of laminin 332 does not appear to influence its recognition by MMP autoantibodies, ELISA systems using both purified, native and recombinant laminin 332 demonstrated a high sensitivity and good correlation with the detection of autoantibodies by immunoblotting. ELISA systems using different laminin 332 preparations represent a feasible and more accessible alternative for a broad range of laboratories.

CONCLUSIONS

Our findings qualify the use of immunoassays with the laminin 332-rich preparations as an ancillary diagnostic tool in mucous membrane pemphigoid.

NGF Modulates trkANGFR/p75NTR in αSMA-Expressing Conjunctival Fibroblasts from Human Ocular Cicatricial Pemphigoid (OCP)

Objective

In a previous study, we reported the upregulation of Nerve Growth Factor (NGF) and trkA^NGFR expression in Ocular Cicatricial Pemphigoid (OCP), an inflammatory and remodeling eye disease. Herein, we hypothesize a potential NGF-driven mechanism on fibroblasts (FBs) during OCP remodeling events. To verify, human derived OCP-FBs were isolated and characterized either at baseline or after NGF exposure.

Materials and Methods

Conjunctival biopsies were obtained from 7 patients having OCP and 6 control subjects (cataract surgery). Both conjunctivas and primary FB cultures were characterised for αSMA, NGF and trkA^NGFR/p75^NTR expression. Subcultures were exposed to NGF and evaluated for αSMA, NGF, trkA^NGFR/p75^NTR expression as well as TGFβ1/IL4 release. For analysis, early and advanced subgroups were defined according to clinical parameters.

Results

OCP-conjunctivas showed αSMA-expressing FBs and high NGF levels. Advanced OCP-FBs showed higher αSMA expression associated with higher p75^NTR and lower trkA^NGFR expression, as compared to early counterparts. αSMA expression was in keeping with disease severity and correlated to p75^NTR. NGF exposure did not affect trkA^NGFR levels in early OCP-FBs while decreased both αSMA/p75^NTR expression and TGFβ1/IL4 release. These effects were not observed in advanced OCP-FBs.

Conclusions

Taken together, these data are suggestive for a NGF/p75^NTR task in the potential modulation of OCP fibrosis and encourages further studies to fully understand the underlying mechanism occurring in fibrosis. NGF/p75^NTR might be viewed as a potential therapeutic target.

Immunohistochemical expression of epithelial cell markers in corneas with congenital aniridia and ocular cicatrizing pemphigoid

PURPOSE

We investigated the immunohistochemical characteristics of corneal specimens in congenital aniridia and pemphigoid using various corneal markers to determine the status of the corneal epithelium.

METHODS

Conjunctivalization was clinically suspected in all corneas. Ten aniridia and seven pemphigoid paraffin-embedded corneal specimens were stained with periodic Schiff reagent (PAS) and antibodies against CK3/12, CK12, CK19, breast cancer resistance protein 1 (BCRP) and p63.

RESULTS

Aniridia: six cases contained goblet cells, four were negative. Both groups had cases with (three of six; one of four) and without CK19 positivity and cases with (two of six; three of four) and without p63 positivity. All aniridia cases except two in the goblet cell group were CK3/12- and CK12-positive and BCRP-negative. Pemphigoid: only one of the seven cases contained goblet cells. This case stained positively for CK19, 3/12, 12 and p63 and negatively for BCRP. The other six cases were positive for CK3/12, five of which were positive for CK12; only one case was CK19-positive. Three cases were p63-positive and two BCRP-positive. The CK12 staining was heterogenous in most cases and was often found in the superficial layer.

CONCLUSION

Three different stages of epithelial characteristics were found in congenital aniridia and pemphigoid: (i) CK19-negative and inhomogenous CK12-positive cases indicating epithelium mainly from (partly) CK12-deficient limbal stem cells; (ii) CK19- and/or goblet cell-positive and CK12-positive cases with their epithelia originating from CK12-deficient limbal stem cells and from incursing conjunctival cells; and (iii) CK19-positive and CK12-negative cases consisting of conjunctival cells alone.

Naturally occurring regulatory T cells in mucous membrane pemphigoid lesions

BACKGROUND

A growing body of evidence suggests the involvement of naturally occurring CD4+ CD25+ regulatory (nTreg) T cells in autoimmune diseases.

OBJECTIVE

To evaluate the expression of some nTreg markers in mucous membrane pemphigoid (MMP) lesions.

METHODS

Lesional biopsies from six patients with untreated MMP were stained immunohistochemically with anti-CD25, -FoxP3, -CD103, and -CCR5.

RESULTS

All of the stained cells, both in MMP lesions and controls, were observed in the interstitial lamina propria or dermis. Positive cell counts of all the markers studied were low or very low in all sections, and significantly higher in MMP specimens than in healthy controls.

CONCLUSIONS

The expression of CCR5 and CD103, which mediate recruitment into peripheral tissues, indicates that CD25+ FoxP3+ nTreg cells may be present in MMP lesions according to a specific homing. nTreg cells may contribute to directing the MMP immunoinflammation towards chronicity, and thus favor the cicatricial evolution of lesions.

Different conjunctival adaptive response in patients with aqueous-deficient and with mucous-deficient dry eyes

PURPOSE

To describe the different cellular adaptive patterns found in the conjunctival epithelium from patients with aqueous-deficient and mucous-deficient dry eyes.

METHODS

The authors studied different conjunctival areas, by impression cytology and by biopsy, 50 eyes with facial nerve paralysis (FNP), 50 eyes with ocular cicatricial pemphigoid (OCP), and 50 eyes from patients with primarily Sjögren syndrome (1SS).

RESULTS

Eyes with FNP from the first clinical grade showed a progressive alteration of the nonsecretory cells, with a significant decrease in density goblet cells, generally with a PAS-positive staining. Eyes with OCP, during clinical grades 1 and 2, showed a slow deterioration of the nonsecretory cells; but from clinical grade 3, there was a significant increase of the cellular size and the thickness of the conjunctiva. Goblet cells showed a significant decrease in density from clinical grade 1, generally with a PAS-negative staining. Eyes with 1SS during clinical grades 1 and 2 showed a progressive alteration of the nonsecretory cells, with a significant decrease in density goblet cells, and a PAS-positive staining. From clinical grade 3 appeared a significant increase of nonsecretory cellular size and thickness of conjunctiva, with a significant decrease in goblet cell counts, and a PAS-negative staining.

CONCLUSIONS

Patients with FNP (a primarily aqueous-deficient alteration) follow completely the squamous metaplasia process. Patients with OCP (a primarily mucous-deficient syndrome) have a hypertrophy and hyperplasia process along the ocular surface. Patients with 1SS (a primarily aqueous-deficient and mucin-deficient alteration) have a squamous metaplasia process, but from clinical grade 3 also appears a hypertrophy and hyperplasia process.

Tumour necrosis factor-alpha in conjunctivae affected by ocular cicatricial pemphigoid

PURPOSE

The presence of tumour necrosis factor-alpha (TNF-alpha) in conjunctivae affected by ocular cicatricial pemphigoid (OCP) was investigated.

METHODS

Biopsy specimens from the conjunctivae of eight patients with OCP, three patients with atopic keratoconjunctivitis (AKC) and two normal subjects were studied for the expression of TNF-alpha by immunohistochemistry. Two independent, masked investigators evaluated the specimens. All samples were similarly processed by a third investigator.

RESULTS

No TNF-alpha was discerned in the normal conjunctival sections; small amounts of TNF-alpha were observed in the atopic keratoconjunctivitis specimens. TNF-alpha was present in substantial amounts in conjunctival sections of patients with OCP. The expression of TNF-alpha was detected in both epithelial and stromal cells of conjunctivae from OCP patients.

CONCLUSIONS

The presence of TNF-alpha in conjunctivae affected by OCP may indicate that this cytokine plays an important role in the production and maintenance of conjuctival inflammation response and subsequent conjunctival scarring in patients with OCP. Further studies clarifying this potential role are warranted.

Blood group related antigens in ocular cicatricial pemphigoid

AIM

To study the MUC5AC and the blood group related antigen expression in ocular cicatricial pemphigoid (OCP) according to the distribution of Lewis and secretor phenotypes in OCP patients compared to normal subjects.

METHODS

Immunostaining was performed on conjunctival biopsy specimens from 22 consecutive patients suffering from OCP, using monoclonal antibodies (Mabs) directed against the peptidic core MUC5AC mucin (anti-M1/MUC5AC Mabs) and against the saccharide moieties (anti-blood group related antigens). These latter included anti-Le(a), anti-Le(b), anti-sialyl Le(a), and H type 2 Mabs, which immunoreact with Lewis positive and non-secretor (Le(a)), Lewis positive and secretor (Le(b)), Lewis positive (sialyl Le(a)), and secretor (H type 2) phenotypes respectively. Serological tests were also performed to confirm the phenotype of each patient. The immunohistopathological patterns and the distribution of Lewis and secretor phenotypes were compared with the results of a previous study in normal individuals.

RESULTS

(1) In OCP patients compared to the normal population, anti-M1 immunoreactivity of goblet cells was unchanged, whereas anti-Le(a), anti-Le(b), and anti-sialyl Le(a) immunoreactivities of epithelial and/or goblet cells were markedly decreased. (2) 41% of OCP patients had a non-secretor phenotype, which is statistically significantly more than the estimated incidence of the same phenotype in the French population (20%) (p approximately 0.04).

CONCLUSIONS

Mucins in OCP patients showed a decreased expression of blood group related antigens whereas the MUC5AC peptidic core detected by anti-M1 Mab remained unchanged. These results also seem to indicate that OCP may be associated with a non-secretor phenotype.

Role of Macrophage Migration Inhibitory Factor in Conjunctival Pathology in Ocular Cicatricial Pemphigoid

PURPOSE

Macrophage migration inhibitory factor (MIF) is a pleiotropic, proinflammatory cytokine that mediates various immunoinflammatory processes. Ocular cicatricial pemphigoid (OCP) is an autoimmune disease in which affected conjunctivae show features of an immunoinflammatory disease. In this study, the role of MIF in the pathogenesis of OCP was examined.

METHODS

The expression of MIF in conjunctival tissues of patients with OCP (n = 10) and normal subjects (n = 5) was studied by quantitative real-time PCR and immunohistochemistry. The production of MIF by conjunctival fibroblasts of normal control subjects and patients with OCP was determined, by using quantitative real-time PCR and enzyme-linked immunosorbent assay (ELISA). In addition, the effects of interleukin (IL)-1, tumor necrosis factor (TNF)-alpha, and transforming growth factor (TGF)-beta1 on the induction of MIF by conjunctival fibroblasts were studied by quantitative real-time PCR. To determine the relationship between conjunctival expression of MIF and accumulation of macrophages, in patients with OCP, a correlation study was performed.

RESULTS

An increased conjunctival expression of MIF was detected in patients with OCP, both at the mRNA (by real-time PCR) and protein level (by immunohistochemistry), compared with normal control patients. The expression of MIF was detected in the epithelial cells and occasionally in the stromal cells in control conjunctival tissues, by immunohistochemistry. In contrast, a statistically significant increase (P < 0.0001) in the expression of MIF was detected in the stromal cells of conjunctival tissues obtained from patients with OCP (control: 4.89 +/- 0.5; OCP: 19.82 +/- 1.34). By quantitative real-time PCR, compared with control conjunctiva, an increase in the expression of MIF was detected in the conjunctiva obtained from patients with OCP. A similar increase in the expression of MIF was also detected in conjunctival fibroblasts of patients with OCP, compared with control fibroblasts, by quantitative real-time PCR. A significantly increased (P < 0.001) level of MIF was also detected in supernatant collected from conjunctival fibroblasts of patients with OCP (186 +/- 5.4), compared with supernatant collected from control fibroblasts (9.3 +/- 7.6). Moreover, IL-1, TNF-alpha, and TGF-beta1, known factors involved in the pathogenesis of OCP, were found to induce the expression of MIF by conjunctival fibroblasts. A statistically significant correlation (P < 0.0001, r(2) = 0.4465) was observed between the expression of MIF and accumulation of CD68-positive macrophages in conjunctiva of patients with OCP.

CONCLUSIONS

This study demonstrated an increased conjunctival expression of MIF in patients with OCP. MIF may be actively involved in the pathogenesis of OCP, possibly regulating the inflammatory events of the disease process.

Relationship between Tear TNF-alpha, TGF-beta1, and EGF levels and severity of conjunctival cicatrization in patients with inactive trachoma

Tear tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta 1 (TGF-beta1), and epidermal growth factor (EGF) levels were determined in patients with inactive trachoma, and a possible relation between these cytokines and conjunctival cicatrization severity was investigated. Forty-four patients with inactive trachoma who were admitted to the Department of Ophthalmology at the Harran University, Sanliurfa, Turkey, were included in this study. The control group consisted of 20 age- and sex-matched healthy subjects. The levels of cytokines in tears were measured by ELISA. Tear samples were collected from the conjunctival cul-de-sac by means of blunted-tip glass capillary tubes. Eyes with inactive trachoma were classified into three subgroups with respect to conjunctiva cicatrization: mild, moderate, and severe. In 44 patients with inactive trachoma, conjunctival cicatrization was found, including mild (n = 15), moderate (n = 16), and severe (n = 13) cases. In patients with inactive trachoma, decreases in tear EGF (p = 0.000) concentrations and increases in tear TGF-beta1 (p = 0.006) and TNF-alpha (p = 0.046) levels with respect to the control group were found to be concordant with conjunctival cicatrization severity. Statistically significant correlations in tear TNF-alpha (p = 0.018), TGF-beta1 (p = 0.007), and EGF (p = 0.043) levels were found between mild and severe cicatrization groups. TNF-alpha and TGF-beta1 have been implicated in the fibrogenic process. Elevated tear levels of inflammatory/fibrogenic cytokines may play an important role in scar formation in trachoma. It is possible that decreased tear levels of EGF, which may be important for the maintenance of corneal epithelial integrity, are related to fibrosis in the lacrimal gland ductules.

Role of connective tissue growth factor in the pathogenesis of conjunctival scarring in ocular cicatricial pemphigoid

PURPOSE

Conjunctival fibrosis due to excessive accumulation of collagens is an important histologic feature in ocular cicatricial pemphigoid (OCP). Studies have suggested a role of transforming growth factor (TGF)-beta1 in conjunctival fibrosis in patients with OCP. Connective tissue growth factor (CTGF) is an important downstream mediator of TGF-beta1-induced collagen synthesis. CTGF usually acts synergistically with TGF-beta1 during the process of fibrosis in various organs. Hence, studying the mechanism by which CTGF influences TGF-beta1-induced synthesis of collagen in conjunctiva of patients with OCP would provide insight into the mechanism of conjunctival fibrosis in patients with OCP.

METHODS

Biopsy specimens from conjunctiva of 10 patients with OCP and 5 normal subjects, were studied, with immunohistochemistry and real-time PCR, for the expression of CTGF and interstitial type I collagen. Using fibroblasts cultured from conjunctival biopsies we determined the effects of TGF-beta1 on the induction of CTGF and type I collagen by immunostaining, and quantitative real-time PCR. The effects of blocking the bioactivity of TGF-beta1 on the expression of CTGF and type I collagen were determined in TGF-beta1-stimulated fibroblasts, before and after treatment with type II receptor neutralizing antibody.

RESULTS

An increased stromal accumulation of interstitial type I collagen with an increased expression of CTGF was observed in biopsy sections of patients with OCP, compared with the control. By quantitative real-time PCR, a 3.2-fold increase in the expression of CTGF was detected in conjunctival tissues obtained from patients with OCP, compared with control conjunctiva. Fibroblasts isolated from conjunctiva of patients with OCP expressed 4.4-fold more CTGF, compared with control conjunctival fibroblasts, by real-time PCR. When these cultured fibroblasts were immunostained, an increased expression of CTGF was detected in fibroblasts isolated from patients with OCP, compared with control. Furthermore, when conjunctival fibroblasts were treated with TGF-beta1, an approximately ninefold increase in the expression of CTGF and an approximately threefold increase in the expression of type I collagen were detected by real-time PCR, compared with unstimulated fibroblasts. Finally, when antibody to TGF-beta type II receptor was added before TGF-beta1 treatment of these fibroblasts, the expression of type I collagen and CTGF was significantly reduced.

CONCLUSIONS

In the present study, an increased expression of CTGF was recorded in conjunctiva of patients with OCP. TGF-beta1 can induce production of CTGF and type I collagen by fibroblasts obtained from conjunctiva in OCP. This induction of CTGF by TGF-beta1 can be blocked by antibody to TGF-beta type II receptors. The findings lead to the conclusion that CTGF is one of the molecules involved in the pathogenesis of conjunctival fibrosis in patients with OCP.

Role of collagen-binding heat shock protein 47 and transforming growth factor-beta1 in conjunctival scarring in ocular cicatricial pemphigoid

PURPOSE

Submucosal fibrosis due to excessive accumulation of collagens is an important histologic feature in the pathogenesis of ocular cicatricial pemphigoid (OCP). Heat shock protein 47 (HSP47), a collagen-binding protein, plays an important role in the biosynthesis of procollagens. In the present study, we examined the role of HSP47 in conjunctival scarring in patients with OCP.

METHODS

Biopsy specimens of the conjunctiva of 15 patients with OCP and 5 normal subjects were studied for the expression of HSP47, transforming growth factor (TGF)-beta1, type I collagen, and type III collagen. The role of TGF-beta1 on the induction of HSP47 and type I collagen by conjunctival fibroblasts was studied by immunostaining, Western blot analysis, and quantitative real-time PCR.

RESULTS

Compared with the control, increased accumulations of type I and type III collagens were detected by immunohistochemistry in fibrotic conjunctiva of patients with OCP. Weak and sparse expression of HSP47 was detected in the epithelial cells and stromal fibroblasts in control conjunctival tissues. In contrast to the control, the expression of HSP47 was markedly increased in the stromal fibroblasts in conjunctival tissues obtained from patients with OCP, as detected by immunohistochemistry. By quantitative real-time PCR, compared with control conjunctival tissues, a 3.4-fold increase in the expression of HSP47 was noted in the conjunctival tissues obtained from patients with OCP. Similar to conjunctival tissues, fibroblasts isolated from conjunctiva of patients with OCP exhibited 4.8-fold increase in the expression of HSP47, compared with control fibroblasts. When conjunctival fibroblasts were treated with various concentration of TGF-beta1, upregulation in the expression of HSP47 and type I collagen was detected.

CONCLUSIONS

This study demonstrated increased expression of HSP47 and TGF-beta1 by conjunctival fibroblasts in biopsy specimens obtained from patients with OCP. TGF-beta1 induced the expression of HSP47 and type I collagen by conjunctival fibroblasts. Increased levels of TGF-beta1 and HSP47 may regulate increased synthesis, assembly, and production of collagens and thereby could significantly contribute to the process of conjunctival scarring in patients with OCP.

Cytokine profile and supposed contribution to scarring in cicatricial pemphigoid

BACKGROUND

The progressive scarring observed in cicatricial pemphigoid (CP) is still partially unexplained but recently the release of soluble fibrogenic factors by inflammatory infiltrating cells has been considered as pathogenically relevant. In the present study we evaluated the expression of mRNA for IL-4, IL-5, TGF-beta1, IFN-gamma in CP in comparison to bullous pemphigoid (BP) patients, investigating the role of cytokine profile as possible cause of the different disease evolution.

METHODS

Biopsies from patients with oral (n = 10), preputial (n = 3) and cutaneous (n = 1) CP were studied by in situ hybridisation performing a new amplification system based on biotinyl-tyramide. As control, four patients affected by BP were also examined, together with healthy tissue from two CP and two BP patients, respectively.

RESULTS

In CP IL-4 mRNA expression was present in 4 out of 14 cases analysed. IL-5 was detected in 12 CP biopsies. TGF-beta1 and IFN-gamma mRNAs were identified in 9 and 11 CP cases, respectively. In BP, IL-4 hybridisation signal could not be observed in any of the cases. By contrast IL-5, TGF-beta1 and IFN-gamma mRNA analyses were positive in all BP cases. Healthy specimens did not show any expression for IL-4, IL-5 and IFN-gamma, while a poor staining for TGF-beta was found in epithelium and subjunctional areas.

CONCLUSIONS

Our results highlight the presence of a mixed cytokine pattern in the cellular infiltrate of both blistering diseases, with a corresponding increase of Th2-like activity in fully developed lesions, irrespective of the different sites involved. In addition, the constant presence of TGF-beta1 mRNA in the different lesional phases of CP, and its overlapping expression in BP suggest that the involvement of additional factors is responsible for the scarring course typical of CP.

Role of enhanced expression of m-CSF in conjunctiva affected by cicatricial pemphigoid

PURPOSE

Local proliferation of macrophages has been reported to augment the inflammatory response in various human and experimental diseases. Macrophage accumulation in the submucosa is also an important feature in the pathogenesis of ocular cicatricial pemphigoid (OCP). In the present study, the role of local proliferation of macrophages in conjunctiva affected by OCP and the relationship between local proliferation of macrophages and expression of macrophage-colony-stimulating factor (m-CSF) in such conjunctiva were examined.

METHODS

Biopsy specimens from the conjunctiva of 10 untreated patients with active OCP and from 5 normal subjects were studied for the expression of m-CSF, macrophages, and proliferating cell nuclear antigen (PCNA), a cell cycle protein, by immunohistochemistry. Dual staining for CD68 (a cell surface marker for macrophages) and PCNA was also performed to identify proliferating macrophages. In addition, fibroblasts isolated from conjunctiva of normal individuals and from patients with OCP were studied for the expression of m-CSF by immunostaining and real-time PCR. To identify the factors that induce m-CSF in conjunctival fibroblasts, the fibroblasts were incubated with different concentrations of interleukin (IL)-1alpha and tumor necrosis factor (TNF)-alpha, and the levels of m-CSF mRNA were determined by real-time PCR and the amount of m-CSF produced was determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Normal conjunctiva showed weak expression of m-CSF in the conjunctival epithelial cells and stroma. Conjunctival expression of m-CSF protein was significantly (P < 0.0001) increased in conjunctival biopsy specimens from patients with OCP. m-CSF was detected in the infiltrating macrophages, stromal cells (presumably fibroblasts), and conjunctival epithelial cells. Compared with normal control conjunctival tissue, a 1.2-fold increase in the expression of mRNA for m-CSF was detected by real-time PCR in the conjunctival tissue obtained from patients with OCP. Increased expression of m-CSF correlated significantly (P < 0.0004) with an increased stromal accumulation of macrophages in conjunctival biopsy specimens of patients with OCP. A number of these accumulated macrophages (CD68-positive) were found to be proliferating (PCNA-positive). In addition, fibroblasts isolated and cultured from conjunctiva of patients with OCP showed significantly increased (1.7-fold) expression of m-CSF compared with normal conjunctival fibroblasts. When conjunctival fibroblasts were treated with IL-1alpha or TNF-alpha, real-time PCR and ELISA detected an increased level of m-CSF.

CONCLUSIONS

An increased expression of m-CSF was observed in conjunctiva from patients with active OCP. There was a positive correlation between expression of m-CSF and accumulation of macrophages in conjunctival biopsy sections obtained from patients with OCP. Increased expression of m-CSF, mainly by conjunctival fibroblasts and infiltrating inflammatory cells, may play an important role in the regulation of local proliferation of macrophages in OCP. In the conjunctiva of patients with OCP, this process could augment or enhance the local inflammatory response and tissue injury consequent to it.

Changes in conjunctival clusterin expression in severe ocular surface disease

PURPOSE

Clusterin is a unique gene transcript in the human ocular surface epithelia and is synthesized by and localized in mucosal epithelia in general. It is not present, however, in keratinized epithelia, such as epidermis. In severe ocular surface disease, pathologic keratinization (squamous metaplasia) of the ordinarily nonkeratinized corneal and conjunctival mucosal epithelia results in severe visual loss. In the current study, the expression of clusterin was examined in conjunctivalized corneas with severe ocular surface disease.

METHODS

We examined conjunctiva covering cornea in eight eyes with ocular surface disease (Stevens-Johnson syndrome and ocular cicatricial pemphigoid) in which pathologic keratinization was present. Normal conjunctiva from four age-matched individuals served as the control. Semiquantitative RT-PCR was used to investigate expression of the clusterin gene. Immunohistochemistry was used to study the distribution of clusterin protein.

RESULTS

The level of clusterin mRNA was significantly lower than normal in the diseased ocular surfaces. Clusterin protein was also markedly decreased in keratinized conjunctiva compared with that in normal eyes.

CONCLUSIONS

Clusterin expression is markedly reduced in the pathologic, keratinized ocular surface epithelium, suggesting its importance in maintaining the ocular surface epithelium as a nonkeratinizing epithelium.

Collagens, collagen-binding heat shock protein 47 and transforming growth factor-beta 1 are induced in cicatricial pemphigoid: possible role(s) in dermal fibrosis

Cicatricial pemphigoid (CP) is an autoimmune mucocutaneous blistering disease associated with scarring. Heat shock protein 47 (HSP47) is thought to play an important role in fibrogenesis, but its role in skin lesions of cicatricial pemphigoid is not yet known. In the present study, we examined the role of HSP47 in dermal fibrosis in cutaneous lesions of a CP patient. Skin biopsies from a patient with CP, and from normal subjects were studied for the expression of HSP47, and interstitial collagens (type I and type III collagens) by immunohistochemistry. Dermal fibroblasts isolated from skin of normal individuals and from fibrotic skin of a CP patient were used to study the expression of HSP47, transforming growth factor beta 1 (TGF-beta 1), type I and type III collagens. Compared to the control skin sections, an increased expression of HSP47 was associated with an increased deposition of interstitial collagens in the fibrotic skin section of the CP patient. Similarly, in contrast to control dermal fibroblasts, the fibroblasts isolated and cultured from fibrotic skin of the CP patient, and grown in vitro, exhibited increased expression of HSP47, type I and type III collagens. Furthermore, compared to the normal control fibroblasts, an increased expression of TGF-beta 1 was detected in the dermal fibroblasts isolated from fibrotic skin of the CP patient. When dermal fibroblasts were treated with various concentrations of TGF-beta 1 (6.25, 12.5, 25, 50 and 100 ng/ml for 24 h), it induced the expression of both type I collagen and HSP47, as determined by quantitative real-time PCR. In conclusion, the expression of TGF-beta 1, HSP47, type I collagen and type III collagen was up-regulated in the fibrotic skin of CP patient, and a complex interaction of these molecules may initiate and propagate the fibrotic cascade in the skin of CP patients.

Tissue and molecular events in human conjunctival scarring in ocular cicatricial pemphigoid

Detailed histomorphometric analysis of human conjunctival biopsy specimens has convincingly demonstrated that tissue remodeling of the extracellular matrix (ECM) is an essential and dynamic process associated with conjunctival scarring in ocular cicatricial pemphigoid (OCP). The conjunctival scarring often eventually results in impaired vision and/or blindness. The molecular mechanisms of conjunctival scarring are not completely understood. Accumulating evidence indicates that the early phase of conjunctival fibrosis is linked with an immuno-inflammatory process mediated by cytokines released by activated conjunctival cells and/or by infiltrating cells. Fibrogenic cytokines secreted by inflammatory cells and fibroblasts might actively be involved in remodeling of the matrix within the conjunctival stroma, possibly by regulating the altered metabolism of matrix proteins.

Elevated expression of transglutaminase 1 and keratinization-related proteins in conjunctiva in severe ocular surface disease

PURPOSE

In severe ocular surface diseases, pathologic keratinization of the ordinarily nonkeratinized corneal and conjunctival mucosal epithelia results in severe visual loss. The expression in conjunctivalized corneas of various proteins known to play important roles in the physiological keratinization process in human epidermis was examined to better understand the mechanism of keratinization.

METHODS

Conjunctiva covering the cornea was examined in 12 eyes with ocular surface disease in the chronic cicatricial phase. These comprised four Stevens-Johnson syndrome, four ocular cicatricial pemphigoid, and four chemical injuries. Normal conjunctivas from four age-matched individuals served as controls. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate transglutaminase 1 gene expression and immunohistochemistry to study the expression of transglutaminase 1 protein along with other keratinization-related proteins (involucrin, loricrin, filaggrin, and cytokeratins 1 and 10) and cytokeratin pairs 4/13 and 3/12.

RESULTS

Semiquantitative RT-PCR showed that transglutaminase 1 mRNA expression was upregulated in keratinized conjunctiva compared with normal. Also, in this tissue, immunohistochemistry demonstrated elevated levels of transglutaminase 1, involucrin, filaggrin, and the cytokeratin pair 1/10. Levels of loricrin and cytokeratin pairs 4/13 and 3/12, however, remained the same.

CONCLUSIONS

Various keratinization-related proteins, transglutaminase 1 included, are most likely involved in the pathogenesis of cicatrizing ocular surface diseases.

Remission of antiepiligrin (laminin-5) cicatricial pemphigoid after excision of gastric carcinoma

PURPOSE

To describe a case of antiepiligrin cicatricial pemphigoid with unusual ocular manifestations and its remission after surgical removal of gastric carcinoma.

METHODS

We describe a 61-year-old Japanese man with antiepiligrin cicatricial pemphigoid.

RESULTS

He presented with conjunctival injection and discharge preceded by a 6-month period of erosive lesions in the oral mucosa and the truncal skin. An advanced gastric carcinoma was found and his serum immunoprecipitated laminin-5. Despite topical treatment with betamethasone, ofloxacin, and artificial tear solutions, serious symblepharon along the Meibomian line developed with little shortening of the inferior conjunctival sac. Following radical gastrectomy, the ocular and cutaneous lesions turned completely quiet.

CONCLUSION

The present case differed from past cases by lacking inferior conjunctival sac shortening and by showing erosive lesions solely at the mucocutaneous junctions. The ocular involvement in this case correlated very well with the severity of gastric carcinoma.

Expression of nerve growth factor receptors on the ocular surface in healthy subjects and during manifestation of inflammatory diseases

PURPOSE

Recent studies have suggested the involvement of nerve growth factor (NGF) in the conjunctival inflammatory process and in corneal epithelium proliferation and differentiation. To verify the hypothesis that NGF could locally modulate the inflammatory and reparative processes, the authors evaluated the expression of NGF high-affinity receptor on the ocular surface in normal and pathologic conditions.

METHODS

Ten conjunctival biopsies (obtained from three healthy subjects, five patients affected by vernal keratoconjunctivitis [VKC], and two patients with cicatricial pemphigoid [CP]) and five corneal specimens obtained from the Eye Bank of Veneto (Italy) were evaluated. All specimens were histologically stained, and immunohistochemistry was performed to identify the NGF high-affinity receptor (TrkA).

RESULTS

All tissues expressed immunoreactivity for NGF receptors. In conjunctival specimens of healthy subjects, basal epithelial cells strongly expressed immunoreactivity and, in the stroma, rare cells were immunopositive for TrkA. No significant difference in immunoreactivity was observed in the conjunctival epithelium between healthy subjects and patients with inflammatory conjunctival diseases, whereas there were more immunopositive cells observed in the conjunctival stroma of VKC and CP patients than in the controls. The immunoreactivity in the cornea was confined to basal epithelial cells and endothelium.

CONCLUSIONS

The NGF receptor is present on the human ocular surface. The authors' data support the possibility that NGF modulates ocular inflammation and corneal epithelial proliferation and differentiation through its receptors.

Analysis of antigens targeted by circulating IgG and IgA autoantibodies in 50 patients with cicatricial pemphigoid

In this study we investigated sera from 50 typical cicatricial pemphigoid (CP) patients. By indirect immunofluorescence on 1 M NaCl-split human skin sections, IgG of 17 sera and IgA of 22 sera reacted with the epidermal side of the split, while IgG of two sera reacted with the dermal side. These latter two sera were later confirmed to be anti-epiligrin CP. By immunoblotting of epidermal extracts, IgG of 14 sera reacted with the 230 kD bullous pemphigoid (BP) antigen (BP230). IgG of 15 sera and IgA of 11 sera reacted with the 180 kD BP antigen (BP180). Interestingly, a bacterial fusion protein containing the BP180 NC16a domain was recognized by IgG of 18 sera but not by IgA of any sera. Fusion proteins containing the C-terminal region of BP180 were recognized by IgG of 20 sera, but it was detected by IgA of only two sera. Our results suggest that, although CP sera show very low titers of autoantibodies, a considerable number of sera contain IgG antibodies to BP180 (either NC16a or C-terminal domain), confirming previous studies. In addition, we showed that greater numbers of IgA antibodies react with BP180, seemingly with different types of epitopes from those for IgG antibodies. Because the specificity of IgG antibodies is not very different from those in BP, IgA antibodies may play a specific role for the development of characteristic clinical features in CP. Future studies should elucidate the pathogenic role of the IgA antibodies in CP.

Costimulatory molecules in ocular cicatricial pemphigoid

PURPOSE

To examine normal and inflamed conjunctiva from patients with ocular cicatricial pemphigoid (OCP) for the presence of costimulatory molecule CD28 and its ligands B7-1 (CD80) and B7-2 (CD86).

METHODS

Conjunctival biopsy specimens from 12 patients with OCP and from five healthy persons undergoing cataract surgery were analyzed by light microscopy and immunohistochemical examination with monoclonal antibody probes for CD28, B7-1, and B7-2 molecules and for mononuclear cell subtypes.

RESULTS

Epithelium of OCP conjunctiva showed more Langerhans' cells, B7-1-positive (+) cells, and B7-2 expression (ratio of B7-2-positive cells to antigen-presenting cells). In the substantia propria, OCP specimens showed significantly increased numbers of T cells (CD3 +), macrophages (CD68+), CD28+ cells, B7-2+ cells (CD86+), Langerhans' cells (CD1a), and B7-1+ cells (CD80). Most of the B7-2+ cells, macrophages, and Langerhans' cells were located subepithelially. B7-2 expression was significantly higher in OCP conjunctival substantia propria compared with normal conjunctiva.

CONCLUSIONS

The results of this study indicate that the expression of the costimulatory molecule B7-2 is upregulated in conjunctiva of patients with active OCP. This increased subepithelial B7-2 expression may contribute to the sustained immune activation in OCP conjunctiva.

Eosinophil granule proteins expressed in ocular cicatricial pemphigoid

BACKGROUND

Blister formation and tissue damage in bullous pemphigoid have been attributed to the release of eosinophil granule proteins--namely, to eosinophil derived cationic protein (ECP) and major basic protein (MBP). In the present investigation these eosinophil granule proteins were studied in the conjunctiva of patients with ocular cicatricial pemphigoid (OCP).

METHODS

Conjunctival biopsy specimens obtained from patients with subacute (n = 8) or chronic conjunctival disease (n = 13) were analysed histologically and immunohistochemically using antibodies directed against EG1 (stored and secreted ECP), EG2 (secreted ECP), MBP, CD45 (common leucocyte antigen), CD3 (pan T cell marker), and HLA-DR (class II antigen).

RESULTS

Subepithelial mononuclear cells, mast cells, and neutrophils were detected in all specimens. The number of mononuclear cells, neutrophils, CD45+ cells, CD3+ cells, and the HLA-DR expression were significantly higher in the subacute than in the chronic disease group. Some eosinophils were found in specimens from five of eight patients with subacute OCP, but in none of the patients with chronic disease. The eosinophil granule proteins (ECP and MBP) were found in the epithelium and substantia propria in patients with subacute conjunctivitis.

CONCLUSIONS

Subepithelial cell infiltration in the conjunctiva greatly differs between subacute and chronic ocular cicatricial pemphigoid specimens. The findings suggest that eosinophil granule proteins may participate in tissue damage in acute phase of inflammation in OCP.

Intermediate filament expression by normal and diseased human corneal epithelium

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.

Laminin-6 and laminin-5 are recognized by autoantibodies in a subset of cicatricial pemphigoid

We characterized basement membrane zone (BMZ) autoantigens targeted by autoantibodies (AAb) from patients with cicatricial pemphigoid. Serum from a patient with severe oral cicatricial pemphigoid contained IgG anti-BMZ AAb. The AAb labeled a lower BMZ component on salt-split skin and localized to the lower lamina lucida/lamina densa by direct and indirect immunoelectron microscopy (IEM) but did not label blood vessels. The AAb did not react with EHS laminin-1 and type IV collagen, pepsinized human type IV collagen, recombinant entactin, or NC1 domain of type VII collagen by dot blotting and western blotting. We focused our studies on the laminin family, as laminin-5 was identified as an autoantigen in cicatricial pemphigoid. Culture-conditioned media from normal keratinocytes (containing laminin-6 and laminin-5) and JEB keratinocytes (containing laminin-6 but not laminin-5) were studied by western blotting. Under nonreducing conditions, the patient's AAb recognized a 600-kDa protein (laminin-6) intensely and a 400-kDa protein (laminin-5) weakly in normal keratinocyte medium even though abundant laminin-5 was present. InJEB keratinocyte medium, however, the 600-kDa protein (laminin-6) alone was recognized by the patient's AAb. The AAb also immunolabeled BMZ of JEB skin that lacked laminin-5. The AAb from this patient and two other patients with anti-laminin-5 cicatricial pemphigoid immunoprecipitated both laminin-6 and laminin-5. Taken together, the results of IEM, non-reducing western blotting, immunoprecipitation, and JEB skin BMZ immunolabeling indicate that laminin-6, as well as laminin-5, is identified by the AAb from a subset of cicatricial pemphigoid patients. We propose the name "anti-laminin cicatricial pemphigoid" for this subset.

Collagen abnormalities in conjunctiva of patients with cicatricial pemphigoid

The purpose of this study was to analyze the distribution and types of collagen in the substantia propria of the conjunctiva of patients with ocular cicatricial pemphigoid (OCP). Biopsy specimens were collected from 10 patients with active OCP, five patients with active Behçet's disease, nine patients with atopic keratoconjunctivitis, five patients with chronic rosacea blepharoconjunctivitis, and six normal patients undergoing cataract surgery. Cryostat tissue sections were cut and stained using an indirect immunofluorescence technique, employing a panel of primary antibodies directed against seven collagen types. Differences between OCP, Behçet's, and normal conjunctiva were seen in the staining for collagen types III, IV, and VII. The intensity of staining for type III collagen was increased in the substantia propria of OCP conjunctiva as compared to the other groups. The basement membrane zone (BMZ) of OCP patients was typically disrupted and fragmented in appearance when stained for type IV collagen, a finding not seen in the non-OCP specimens. The BMZ staining pattern for type VII collagen in OCP conjunctiva was even more disrupted than that seen for type IV collagen, particularly on the posterior side, which was thickened and reduplicated with short fibers extending into the superficial stroma. The production of type III collagen by fibroblasts of the substantia propria is a common feature of diseases associated with subepithelial fibrosis. The damage to the epithelial BMZ and the subsequent attempt at repair with aberrant type IV and VII collagen production are unique to conjunctiva affected by OCP.

Biological activity of N-(4-hydroxyphenyl) retinamide-O-glucuronide in corneal and conjunctival cells of rabbits and humans

Previous studies of topical retinoic acid for treatment of ocular surface disease met with limited success due to instability and irritancy of the retinoid and lack of efficacy in keratoconjunctivitis sicca. There has, however, been continued interest in the treatment of mucin deficiency and cicatrizing conjunctival diseases, such as ocular cicatricial pemphigoid (OCP), topically with retinoids. In this study the biological activity of stable, water-soluble, synthetic retinoid, N-(4-hydroxyphenyl) retinamide-O-glucuronide (4-HPROG) was investigated in vivo and in vitro using conjunctival and corneal epithelium and fibroblasts. Vitamin A-deficient rabbits with stage 3-4 corneal xerosis and squamous metaplasia confirmed by conjunctival impression cytology were treated with topical 0.1% 4-HPROG in an artificial tear vehicle for 3 weeks. Impression cytology was repeated at 2 and 3 weeks and at 3 weeks conjunctival biopsies were fixed for histology. Growth curves were generated using conjunctival fibroblasts of rabbits and humans (normals and patients with cicatrizing conjunctival disease including OCP and Stevens-Johnson syndrome) cultured in the 10(-8)-10(-6) M 4-HPROG. In vivo, corneal xerosis cleared in three days. A normal conjunctival epithelium was restored by 2 weeks and goblet cells were present by 3 wk, with no change in vehicle-treated controls. No ocular irritation occurred. In vitro, 10(-6) M 4-HPROG inhibits growth of rabbit conjunctival fibroblasts. The retinoid had no effect on proliferation of conjunctival fibroblasts from normal humans but the doubling time of cells from patients with OCP increased significantly, from 50.9 +/- 10.01 h (control) to 61.5 +/- 8.95 h (retinoid). Proliferation of conjunctival fibroblasts from a patient with Stevens-Johnson syndrome was also inhibited. N-(4-hydroxyphenyl) retinamide-O-glucuronide is biologically active and merits further study to determine its efficacy in controlling conjunctival fibrosis and treating ocular surface squamous metaplasia.

Changes in the expression of integrins and basement membrane proteins in benign mucous membrane pemphigoid

OBJECTIVE

To determine the location of the subepithelial split in benign mucous membrane pemphigoid (BMMP) and its relationship to the anchoring filaments and their receptors.

MATERIALS AND METHODS

Frozen sections of lesional and perilesional oral mucosa from 10 cases of BMMP were stained, using an immunofluorescence method, for the beta-1, beta-4, alpha-3 and alpha-6 integrin subunits and for their ligands, laminin I and laminin V (kalinin). In all cases the diagnosis was confirmed by the demonstration of linear staining for IgG at the basement membrane zone. Six specimens of normal mucosa were stained for comparison.

RESULTS

Staining for integrins, laminin and kalinin in perilesional mucosa was similar to normals, although one case showed loss of alpha-6 and beta-4 . In lesional mucosa, laminin and kalinin showed strong linear staining localised to the floor of the bullae. The alpha-6 and beta-4 subunits were expressed only on the roof of the bullae but staining was weak and patchy with areas of loss. In some sections alpha-6 showed a punctate intracellular distribution similar to IgG. The distribution of alpha-3 and beta-1 was similar to that seen in normals.

CONCLUSIONS

In all cases kalinin was found on the connective tissue side of the lesions and alpha-6 beta-4 localised to the epithelial side. This shows that the split occurs at a location which separates anchoring filaments from the hemidesmosomes. Loss of the alpha-6 beta-4 integrin in the lesions and the similar intracellular staining of alpha-6 and IgG, suggest that disruption of hemidesmosomes may be a key event in the immunopathogenesis of the lesions and that the alpha-6 integrin subunit is a potential antigen in oral mucosal BMMP.

Heat shock protein expression in human conjunctiva

PURPOSE

To examine the distribution of human heat shock proteins (HSPs) HSP90, inducible HSP70 (iHSP70), constitutive and inducible HSP70 (cHSP70), HSP65, and human HSP27 in conjunctival biopsy specimens of ocular cicatricial pemphigoid (OCP), atopic keratoconjunctivitis, and healthy persons with cataract.

METHODS

Using an immunoperoxidase technique, conjunctival biopsy specimens from ten patients with ocular cicatricial pemphigoid, ten patients with atopic keratoconjunctivitis and ten healthy persons undergoing cataract surgery were analyzed with a panel of monoclonal antibodies directed against human HSPs.

RESULTS

Large amounts of HSP90 and HSP27, and lesser amounts of cHSP70, iHSP70, and HSP65 were present in atopic keratoconjunctivitis and normal epithelium; less of these proteins were seen in OCP conjunctival epithelium. In atopic keratoconjunctivitis and normal tissue the substantia propria contained a few HSP-positive cells, and the vascular endothelium was consistently negative for all of the HSPs. In sharp contrast, OCP stroma contained large numbers of cells staining for HSP27, HSP90, and iHSP70, and the vasculature was strongly positive, particularly for HSP90, cHSP70, and HSP27.

CONCLUSION

These results indicate that normal and atopic keratoconjunctivitis epithelia express HSP90 and HSP27 and some form of HSP65 and HSP70. The differences between normal, atopic keratoconjunctivitis, and OCP stromal staining suggest an upregulated expression of HSP90, cHSP70, and HSP27 at the site of inflammation in OCP, the stroma, from cytokine release. The striking presence of HSP in the conjunctival vascular endothelium from OCP patients suggests a previously unappreciated role of the vasculature in OCP.

Cytokines in the conjunctiva of acute and chronic mucous membrane pemphigoid: an immunohistochemical analysis

The aim of this study was to evaluate the potential role of certain soluble factors in conjunctival scar tissue formation of pemphigoid patients. Epibulbar conjunctival biopsy specimens were taken from patients with acute ulcerative (n = 4), subacute (n = 8) and chronic (n = 8) mucous membrane pemphigoid and from twelve age-matched healthy individuals. The tissues were embedded in glycol methacrylate and analysed by immunohistochemical methods. Interleukin-2 (IL-2), interferon-gamma, transforming growth factor-beta (TGF-beta), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), tumour necrosis factor-alpha and proliferating cells (as identified with the antibody Ki-67) were found in both pemphigoid patients and normal controls. Interleukin-4 was not found with this method in either normal or diseased conjunctiva. Significant differences between normal and diseased conjunctiva were found for TGF-beta and for proliferating cells, which were both increased in the acute disease group. More intense staining was found in the subacute disease group for IL-2, bFGF and PDGF. Our findings showed that a variety of cytokines were present in normal and diseased bulbar conjunctiva. Acute conjunctival disease in mucous membrane pemphigoid may indicate active scar tissue formation, implied by an increase in TGF-beta and the presence of proliferating fibroblasts.

Detection of ocular mucus in normal human conjunctiva and conjunctiva from patients with cicatricial pemphigoid using lectin probes and histochemical techniques

Conjunctival biopsies from patients with cicatricial pemphigoid affecting the conjunctiva and patients undergoing cataract surgery (normal conjunctiva) were snap-frozen, cryostat sectioned and incubated with fluorescein-conjugated lectins; peanut agglutinin (PNA), Helix pomatia agglutinin (HPA), soybean agglutinin (SBA), wheat germ agglutinin (WGA) and succinylated wheat germ agglutinin (S-WGA). Controls consisted of preincubating the lectins with the appropriate blocking sugars before applying the lectins to the sections. PNA and HPA stained the mucus granules contained in the conjunctival goblet cells but did not stain mucus or glycocalyx at the ocular surface distal to the goblet cells. Native WGA and S-WGA had high affinities for conjunctival goblet cells and the apical epithelial cell layers. Native WGA stained mucus and glycocalyx at the ocular surface. This staining of the ocular surface by WGA was confirmed at the transmission electron microscopic level using WGA conjugated to ferritin. Cicatricial pemphigoid patients in this study had reduced numbers of goblet cells; however, those goblet cells which were observed in cicatricial pemphigoid conjunctiva stained positively with HPA, PNA, WGA, and SWGA as did goblet cells in normal conjunctiva.

Scanning electron microscopy of conjunctival surfaces in patients with ocular cicatricial pemphigoid

The conjunctival surfaces of ten patients with active, ocular cicatricial pemphigoid, three patients with drug-controlled ocular cicatricial pemphigoid, and six patients with normal conjunctivas were studied using scanning electron microscopy. A homogeneous granular sheet of amorphous mucin-like material was observed covering extensive areas of the conjunctiva in eight of ten patients with active ocular cicatricial pemphigoid. This sheet of amorphous material was absent on drug-controlled ocular cicatricial pemphigoid and normal conjunctival specimens. Our study demonstrates that patients with active ocular cicatricial pemphigoid possess ocular surface mucus that appears thicker and more continuous than normal ocular mucus when observed with scanning electron microscopy. This observation is in agreement with clinical observations of thick mucus strands in the inferior fornix of patients with active ocular cicatricial pemphigoid.

SDS-gradient polyacrylamide gel electrophoresis of individual ocular mucus samples from patients with normal and diseased conjunctiva

Individual mucus samples were collected from normal individuals and from patients with ocular cicatricial pemphigoid (CP), Stevens-Johnson syndrome (SJS), and various types of conjunctival inflammation (rosacea, meibomianitis, atopy, keratoconjunctivitis sicca, etc.). The mucus samples were dissolved in sample buffer containing 8M urea, 2% SDS and 5% 2-mercaptoethanol and were electrophoresed on gradient 2-16% polyacrylamide gels. Four glycoproteins with molecular weights greater than 200,000 daltons were consistently observed in both individuals with normal conjunctiva and patients with CP, SJS, and other diseases exhibiting conjunctival inflammation. The amounts of each glycoprotein appeared to vary from one individual to another; however, the presence or absence of specific glycoproteins could not be correlated with the different ocular diseases. The techniques described for mucus analysis offer advantages over previously published techniques since improved resolution of the mucous glycoproteins can be achieved by electrophoresis on 2-16% gradient gels, and individual samples can be analyzed. Our results suggest that substantial amounts of ocular mucous glycoprotein are present in the eyes of patients with CP and SJS, diseases which have been previously described as mucin-deficient dry eye syndromes.

Localization of basement membrane components in mucous membrane pemphigoid

We examined the distribution of laminin, type IV collagen, and fibronectin in subepithelial vesicles of oral mucous membrane pemphigoid (MMP). Indirect immunofluorescence staining of these macromolecules was performed on 10 frozen biopsy specimens of oral MMP. We found type IV collagen in the connective tissue floor and laminin in the epithelial roof of these lesions. Our results suggest that the inflammatory injury in oral MMP may disrupt the interaction of laminin with type IV collagen in the basement membrane zone.

Alterations in fibronectin distribution in oral mucosal vesiculo-bullous lesions

The distribution of fibronectin in human oral mucosal vesiculo-bullous diseases was studied by indirect immunofluorescence. Subepithelial (benign mucous membrane pemphigoid and erythema multiforme) as well as intraepithelial (pemphigus vulgaris and dyskeratosis follicularis) lesions were selected. A marked accumulation of fibronectin was generally found in the lamina propria and basement membrane region, except in dyskeratosis follicularis. Intraepithelial staining occurred in erythema multiforme and dyskeratosis follicularis. In pemphigus vulgaris intercellular staining was seen in relation to acantholysis. Both mucous membrane pemphigoid and erythema multiforme showed a linear accumulation corresponding to the intact basement membrane. However, only pemphigoid lesions disclosed fibronectin on the epithelial side of the vesicles.