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A Non-invasive Way to Isolate and Phenotype Cells from the Conjunctiva
Published on: July 5, 2017
No apparent association between periocular and ocular microcolonization and the degree of inflammation in patients
E Nivenius1, P G Montan, E Chryssanthou
1Department of Clinical Sciences, Karolinska Institutet, Division of Ophthalmology, St Erik's Eye Hospital, Stockholm, Sweden.
Background:
The cause of the chronic inflammation in atopic keratoconjunctivitis (AKC), the ocular manifestation of atopic eczema/dermatitis syndrome, is largely unknown.
Objective:
To investigate the possibility that microorganisms may be important in the inflammatory activity in AKC.
Methods:
Fifteen patients with AKC participated in the study. The presence of aerobic bacteria and fungi was related to the severity of clinical signs, the numbers of inflammatory cells in tears and conjunctival biopsies, and the concentration of various cytokines in tears. In addition, serological evidence for IgE sensitization to Staphylococcus aureus B antigen and Malassezia sympodialis antigen was investigated. Twelve healthy subjects were included for control purposes.
Results:
The patients exhibited moderate clinical signs of AKC. No relation was found between the severity of AKC and the presence of microorganisms, despite the fact that S. aureus was frequently isolated. AKC patients showed significantly higher levels of IFN-gamma, TNF-alpha (tumour necrosis factor-alpha), IL-2, IL-4, IL-5 and IL-10 than controls. An association was found between conjunctival signs and the levels of all cytokines except IL-5.
Conclusion:
We found no evidence to suggest that periocular and ocular microcolonization are related to inflammatory parameters in AKC. However, confirmation of the present results in a longitudinal study with repeated clinical examinations and samplings in the same individual is required before the contribution of S. aureus to on-going inflammation in AKC can be dismissed.
Insights
Microorganisms like Staphylococcus aureus were frequently found in atopic keratoconjunctivitis (AKC) but not linked to inflammation severity. Elevated cytokine levels were observed in AKC patients, suggesting other inflammatory pathways are involved.
Area of Science:
- Ophthalmology
- Immunology
- Microbiology
Background:
- Atopic keratoconjunctivitis (AKC) is an ocular condition linked to atopic eczema/dermatitis syndrome.
- The underlying causes of chronic inflammation in AKC remain largely unknown.
Purpose of the Study:
- To explore the potential role of microorganisms in the inflammatory processes of AKC.
- Investigate the association between microbial presence and clinical manifestations of AKC.
Main Methods:
- Studied 15 AKC patients and 12 healthy controls.
- Assessed aerobic bacteria and fungi, inflammatory cells in tears and biopsies, and tear cytokine concentrations.
- Examined serological evidence for IgE sensitization to Staphylococcus aureus and Malassezia sympodialis antigens.
Main Results:
- No correlation found between microbial presence and AKC severity, despite frequent isolation of S. aureus.
- AKC patients exhibited significantly higher levels of multiple cytokines (IFN-gamma, TNF-alpha, IL-2, IL-4, IL-10) compared to controls.
- Conjunctival signs were associated with elevated levels of most tested cytokines, excluding IL-5.
Conclusions:
- No evidence suggests periocular or ocular microcolonization directly relates to inflammatory parameters in AKC.
- Further longitudinal studies are needed to definitively assess the role of S. aureus in ongoing AKC inflammation.
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