DESIGN: A comparative cross sectional study.
PARTICIPANTS: Patients were divided into Group 1 (allergic rhinitis without conjunctivitis), Group 2 (allergic rhinoconjunctivitis), and Group 3 (normal population).
METHODS: A comparative cross-sectional study was conducted. Patients were divided into; Group 1 (allergic rhinitis without conjunctivitis), Group 2 (allergic rhinoconjunctivitis), and Group 3 (normal controls). Tears were collected using Schirmer strips and cytokine analysis performed using enzyme linked immunosorbent assay.
RESULTS: There were a total of 68 subjects. Median values of cytokines in the allergic rhinitis group were as follows; TNFa (45.34 pg/ml), IL-4 (61.91 pg/ml), IL-5 (8.92 pg/ml), IL-6 (538.37 pg/ml) and IL-8 (1438.72 pg/ml). Cytokine levels in the group with allergic rhinoconjunctivitis were approximately two-fold higher than in the group with allergic rhinitis only. The median cytokine level in the control group was lowest. A significant inter-group difference was observed for TNF-alpha, IL-4, IL-6 and IL-8 levels, with allergic rhinoconjunctivitis patients demonstrating significantly elevated cytokines compared to those with allergic rhinitis only (p<0.001). These four cytokines were also significantly higher in those with allergic rhinitis than in controls (p<0.005). Although the group with allergic rhinoconjunctivitis had the highest levels of IL-5, no statistically significant inter-group difference was noted (p=0.479).
CONCLUSION: This study demonstrated the presence of raised tear film inflammatory cytokines even in allergic rhinitis patients without ocular symptoms. These patients may be at increased risk of developing allergic conjunctivitis. These findings not only substantiate the immunological theory of the naso-ocular reflex, but have clinical and therapeutic implications for the holistic management of allergic rhinitis and conjunctivitis.
OBJECTIVE: This study aimed to compare the mean percentages and absolute counts of CD4+ memory T cell subsets between: (i) non-allergic controls and AR patients; (ii) mild AR patients and moderate-severe AR patients.
METHODS: Sensitization to Dermatophagoides farinae and Dermatophagoides pteronyssinus were determined in 33 non -allergic controls, 28 mild AR and 29 moderate-severe AR patients. Flow cytometry was used to determine the percentage of CD4+ na?ve (TN; CD45RA+CCR7+), central memory (TCM; CD45RA-CCR7+), effector memory (TEM; CD45RA-CCR7-) and TEMRA (CD45RA+CCR7-) T cells from the peripheral blood. The absolute counts of CD4+ T cell subsets were obtained by dual platform method from flow cytometer and hematology analyzer.
RESULTS: There were no significant differences in the mean percentages and absolute counts of CD4+ T cell subsets between non-allergic controls and AR patients sensitized to HDMs. However, there were significant reduction in the mean percentage (p=0.0307) and absolute count (p=0.0309) of CD4+ TEMRA cells in moderate-severe AR patients compared to mild AR patients sensitized to HDMs and 13/24 (54.2%) moderate-severe AR patients sensitized to HDMs had persistent symptoms.
CONCLUSION: Reduction in the mean percentage and absolute count of CD4+CD45RA+CCR7- TEMRA cells were observed in moderate-severe AR patients compared to mild AR patients in our population of AR patients sensitized to HDMs.