Purchase this article with an account.
Andrea Leonardi, Giuseppe DeFranchis, Francesca Zancanaro, Giovanna Crivellari, Massimo De Paoli, Mario Plebani, Antonio G. Secchi; Identification of Local Th2 and Th0 Lymphocytes in Vernal Conjunctivitis by Cytokine Flow Cytometry. Invest. Ophthalmol. Vis. Sci. 1999;40(12):3036-3040.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. Th2 lymphocytes may play a key role in the development of allergic diseases such as
vernal keratoconjunctivitis (VKC). Cytokine flow cytometry of tear
samples was used to identify the phenotypical and functional properties
of lymphocytes at the actual site of the allergic reaction.
methods. Tear and blood samples were obtained from patients affected by active
VKC (n = 12) and from normal control subjects (n= 10). Tears were obtained after gentle scraping of the tarsal
and bulbar conjunctiva. Tear and blood samples were placed in a
solution of brefeldin-A, phorbol myristate acetate (PMA),
ionomycin, and RPMI for 4 hours and then processed for flow cytometry.
Lymphocytes were marked with the monoclonal antibodies, anti-IFN-γ
and anti-interleukin (IL)-4. Levels of IL-4, IL-2, IFN-γ, IL-2R,
total IgE, eosinophil cationic protein (ECP), eosinophil protein
X/neurotoxin (EPX), and myeloperoxidase (MPO) were also evaluated in
results. Expression of IL-4 was observed in 9.2% ± 9.5% of lymphocytes in
tears of patients with VKC. Of the 12 patients with VKC, 8 (67%) had
tear lymphocytes positive for IL-4 (Th2). Two patients (17%) had a
double population of lymphocytes: One was positive for Th2, and the
other was positive for both IL-4 and IFN-γ (Th0). One patient (8%)
was positive for IFN-γ (Th1) only, and one patient was negative for
both ILs. No differences in the percentage of Th2 lymphocytes were
found between tarsal and limbal patients. The percentage of Th2
lymphocytes was significantly correlated with the severity of the
disease. No positive lymphocytes were found in tears of control
subjects. Eosinophils, serum IgE, ECP, and EPX were all significantly
higher in VKC than in control subjects.
conclusions. In ocular allergic diseases, local lymphocytes expressed the Th2
phenotype and, to a lesser degree, the Th0 phenotype. Although results
of systemic allergic markers can be inconclusive in patients with VKC,
flow cytometry demonstrated a local lymphocyte phenotype that can
account for the clinical and histologic abnormalities of
This PDF is available to Subscribers Only