Phenotypic characterization of inflammatory cells in phlyctenular eye disease

Abstract

Phlyctenular conjunctival biopsy specimens obtained from seven patients presenting with ulcerated limbal phlyctens were examined with routine histology and immunohistochemistry using a panel of monoclonal and polyclonal antibodies and immunoperoxidase techniques. Large numbers of mononuclear phagocytes, dendritic Langerhans cells and polymorphonuclear leukocytes and moderate numbers of T-lymphocytes were observed in the epithelium. This infiltrate was most intense at the basal epithelial layers which expressed HLA-DR antigens. The underlying stromal inflammatory infiltrate was organized as perivascular cuffs and a scattered subepithelial infiltrate, and consisted of many mononuclear cells and poly-morphonuclear leukocytes. Among the mononuclear cells, monocyte derived cells dominated and included monocytes macrophages and dendritic cells. T-lymphocytes were present in moderate numbers, whereas B-lymphocytes and plasma cells, mostly of IgA class, were infrequent. These findings provided in situ immunohistochemical evidence that phlyctenular eye disease is the result of delayed type hypersensitivity immune response in which monocytes and monocyte derived cells play a central role.

Dual Role of Cutibacterium acnes: Commensal Bacterium and Pathogen in Ocular Diseases

“…Laboratory research has proven that C. acnes can induce DTH response in the rat cornea; heat-killed C. acnes can induce inflammatory cellular infiltration in the C. acnes -immunized rat cornea [ 60 ]. An immunohistochemical study revealed that CD4+ T cells infiltrated predominately over CD8+ T cells [ 60 ], a finding which is compatible with those of immunohistochemical studies of conjunctival phlyctenules [ 62 ]. Therefore, C. acnes can be causative for both meibomitis and corneal/conjunctival phlyctenules (cellular infiltrates) in MRKC.…”

Dual Role of Cutibacterium acnes: Commensal Bacterium and Pathogen in Ocular Diseases

“…Laboratory research has proven that C. acnes can induce DTH response in the rat cornea; heat-killed C. acnes can induce inflammatory cellular infiltration in the C. acnes -immunized rat cornea [ 60 ]. An immunohistochemical study revealed that CD4+ T cells infiltrated predominately over CD8+ T cells [ 60 ], a finding which is compatible with those of immunohistochemical studies of conjunctival phlyctenules [ 62 ]. Therefore, C. acnes can be causative for both meibomitis and corneal/conjunctival phlyctenules (cellular infiltrates) in MRKC.…”

Meibomitis-Related Keratoconjunctivitis

“…This result was comparable with those observed previously for conjunctival phlyctens. 28 We postulate that P. acnes may be able to survive even during monocyte and neutrophil infiltration, thus prolonging the DTH response, and possibly causing granulomatous lesions such as phlyctenular keratitis on the ocular surface. …”

Inflamed Obstructive Meibomian Gland Dysfunction Causes Ocular Surface Inflammation

“…This finding is compatible with those of immunohistochemical studies of conjunctival phlyctens. 45 P. acnes, in concert with coagulase-negative staphylococci, are known to be the most common commensal bacteria of the eyelid and conjunctiva. 46 S. aureus is also known to produce previously characterized triglyceride lipases.…”

Dual Role of Cutibacterium acnes: Commensal Bacterium and Pathogen in Ocular Diseases

“…Laboratory research has proven that C. acnes can induce DTH response in the rat cornea; heat-killed C. acnes can induce inflammatory cellular infiltration in the C. acnes -immunized rat cornea [ 60 ]. An immunohistochemical study revealed that CD4+ T cells infiltrated predominately over CD8+ T cells [ 60 ], a finding which is compatible with those of immunohistochemical studies of conjunctival phlyctenules [ 62 ]. Therefore, C. acnes can be causative for both meibomitis and corneal/conjunctival phlyctenules (cellular infiltrates) in MRKC.…”

Meibomitis-Related Keratoconjunctivitis

“…This result was comparable with those observed previously for conjunctival phlyctens. 28 We postulate that P. acnes may be able to survive even during monocyte and neutrophil infiltration, thus prolonging the DTH response, and possibly causing granulomatous lesions such as phlyctenular keratitis on the ocular surface. …”

Inflamed Obstructive Meibomian Gland Dysfunction Causes Ocular Surface Inflammation

“…This finding is compatible with those of immunohistochemical studies of conjunctival phlyctens. 45 P. acnes, in concert with coagulase-negative staphylococci, are known to be the most common commensal bacteria of the eyelid and conjunctiva. 46 S. aureus is also known to produce previously characterized triglyceride lipases.…”

Dual Role of Cutibacterium acnes: Commensal Bacterium and Pathogen in Ocular Diseases

“…Laboratory research has proven that C. acnes can induce DTH response in the rat cornea; heat-killed C. acnes can induce inflammatory cellular infiltration in the C. acnes -immunized rat cornea [ 60 ]. An immunohistochemical study revealed that CD4+ T cells infiltrated predominately over CD8+ T cells [ 60 ], a finding which is compatible with those of immunohistochemical studies of conjunctival phlyctenules [ 62 ]. Therefore, C. acnes can be causative for both meibomitis and corneal/conjunctival phlyctenules (cellular infiltrates) in MRKC.…”

Meibomitis-Related Keratoconjunctivitis

“…This result was comparable with those observed previously for conjunctival phlyctens. 28 We postulate that P. acnes may be able to survive even during monocyte and neutrophil infiltration, thus prolonging the DTH response, and possibly causing granulomatous lesions such as phlyctenular keratitis on the ocular surface. …”

Inflamed Obstructive Meibomian Gland Dysfunction Causes Ocular Surface Inflammation

“…This finding is compatible with those of immunohistochemical studies of conjunctival phlyctens. 45 P. acnes, in concert with coagulase-negative staphylococci, are known to be the most common commensal bacteria of the eyelid and conjunctiva. 46 S. aureus is also known to produce previously characterized triglyceride lipases.…”