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Published on: July 5, 2017
Activation of Conjunctiva-Associated Lymphoid Tissue in Patients With Infectious Keratitis Using In Vivo Confocal
Yuting Liu1,2, Rui Zhu1,2, Xin Jin1,2
1Eye Hospital, The First Affiliated Hospital of Harbin Medical University, Harbin City, Nangang District, Heilongjiang Province, Harbin, China.
Insights
Conjunctiva-associated lymphoid tissue (CALT) is activated in patients with keratitis, playing a key role in the disease. This immune response was also observed in the unaffected eye of affected individuals.
Area of Science:
- Ophthalmology
- Immunology
- Microbiology
Background:
- Conjunctiva-associated lymphoid tissue (CALT) is a crucial component of ocular immunity.
- Its role in infectious eye diseases like keratitis is not fully understood.
- Understanding CALT activation can provide insights into keratitis pathogenesis.
Purpose of the Study:
- To evaluate the activation of CALT in patients diagnosed with keratitis.
- To investigate the role of CALT in the pathogenesis of keratitis.
- To compare CALT characteristics in keratitis patients versus healthy controls.
Main Methods:
- In vivo confocal microscopy (IVCM) to visualize conjunctival structures.
- Conjunctival impression cytology (CIC) for cellular analysis.
- Immunofluorescence staining to identify immune cell populations (CD4+, CD8+).
Main Results:
- Significantly higher diffuse lymphoid tissue cell density, perifollicular lymphocyte density, and follicular area in keratitis patients.
- Increased CD4+ and CD8+ T-cell proportions in the conjunctiva of keratitis patients.
- Evidence of CALT activation in the contralateral, unaffected eye of keratitis patients.
Conclusions:
- CALT is activated in keratitis, indicating its significant role in the disease's development.
- This activation extends to the contralateral eye, suggesting a systemic ocular immune response.
- CALT's involvement in keratitis pathogenesis has been previously underestimated.
Purpose:
We aimed to evaluate activation of conjunctiva-associated lymphoid tissue (CALT) in patients with keratitis using in vivo confocal microscopy (IVCM) and conjunctival impression cytology (CIC).
Methods:
In addition to anterior segment photography and corneal fluorescein staining, IVCM revealed the palpebral conjunctiva in all subjects, and CIC and immunofluorescence staining were performed.
Results:
Diffuse lymphoid tissue cell density in the eyes of patients with keratitis was significantly greater compared with healthy volunteers (P < 0.001). Similar trends were found in perifollicular lymphocyte density (P < 0.001), follicular density (P = 0.029), follicular center reflection intensity (P = 0.011), and follicular area (P < 0.001). Immunofluorescence staining showed that the proportions of CD4+ (61.7% ± 8.0% vs. 17.3% ± 10.2%, respectively, P < 0.001) and CD8+ (46.9% ± 10.0% vs. 19.6% ± 11.5%, respectively, P < 0.001) cells in patients with keratitis was greater compared with healthy volunteers. Interestingly, we also observed changes in the contralateral eye in subjects with keratitis.
Conclusions:
Our research suggests that CALT, as an ocular immune structure, is activated and plays an important role in the pathogenesis of keratitis. This has been overlooked previously. CALT is also active in the contralateral eye of subjects with keratitis.
