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A flow cytometric study about the immunopathology of vernal keratoconjunctivitis
A M Avunduk1, M C Avunduk, V Dayanir
1Karadeniz Technical University, School of Medicine, Department of Ophthalmology, Trabzon, Turkey.
Insights
Vernal keratoconjunctivitis (VKC) involves T lymphocyte immune responses. Increased CD4+ and CD4/29+ cells in tears during spring may worsen VKC symptoms.
Area of Science:
- Ophthalmology
- Immunology
- Allergy
Background:
- Vernal keratoconjunctivitis (VKC) is a seasonal, bilateral inflammation of the conjunctiva.
- The precise pathogenesis of VKC remains unclear, though T-lymphocyte-mediated immune reactions are implicated.
Purpose of the Study:
- To investigate the specific role of T lymphocytes and their subsets in the development of VKC.
- To correlate T cell populations in tear samples with VKC activity and symptom severity.
Main Methods:
- Tear samples were collected from VKC patients and healthy volunteers during active (spring) and quiescent (winter) phases.
- Flow cytometry was used to quantify percentages of CD4/29+, CD4/45RA+, CD4+, and CD8+ T cells in tear samples.
- Statistical analysis included Wilcoxon matched-pair signed-rank and Mann-Whitney U tests to compare groups.
Main Results:
- Tear samples from VKC patients showed significantly higher percentages of CD4+ and CD4/29+ T cells during the active spring period.
- These T cell populations returned to normal levels during the quiescent winter stage.
- No significant seasonal changes in CD4/45RA+ or CD8+ T cells were observed; patient symptoms correlated with disease activity.
Conclusions:
- Elevated levels of CD4+ and CD4/29+ T cells in tears are associated with VKC exacerbation during the spring.
- These findings suggest a key role for specific T cell subsets in the seasonal inflammatory response of VKC.
Background:
Vernal keratoconjunctivitis (VKC) is a bilateral seasonal conjunctival inflammation. Exact pathogenesis of the disease is unknown, but some evidences suggest TH lymphocyte-mediated immune reactions.
Objective:
The aim of this study was to investigate the role of the T lymphocyte and its subsets in the pathogenesis of VKC.
Methods:
We obtained tear samples from patients with VKC and normal volunteers during active (spring) and quiescent (winter) periods. The patients' records were also obtained for assessment of symptom scores. The percentages of CD4/29+, CD4/45RA+, CD4+, and CD8+ in tear samples were established by using flow cytometry, and the results of all three groups were compared with each other by using the Wilcoxon matched-pair signed-rank test and the Mann-Whitney U test.
Results:
The percentages of CD4/29+ and CD4+ cells in tears of patients with VKC increased significantly in the active period and decreased to normal levels in the quiescent stage. In contrast, the percentages of CD4/45RA+ and CD8+ cells in tears of patients with VKC did not show any significant change between spring and winter. The patients' symptoms were significantly lower in the quiescent period (winter) compared with the active stage (spring).
Conclusion:
We propose that increased numbers of CD4+ and CD4/29+ cells in tears may be exacerbating the disease during the spring season.