Results
Eighteen patients with VKC (15 males and 3 females, mean age 10.7±5.7 years) were included in the study. Ten healthy subjects (6 males, 4 females, mean age 8±3years) were included as control group. Nine patients with VKC (7 males, 2 females, mean age 9±2.3 years) were in the active phase (group A) of VKC, 5 (4 males, 1 female, mean age 8.5±4.4 years) were in the quiescent phase (group Q) and 4 patients (4 males, mean age 22±5 years) were included in the recovery group (R). Eleven (61%) out of 18 patients showed positive skin prick test for aeroallergens. Demographic and clinical characteristics of patients included in this study are summarized in Table 1.
Patients with VKC showed significant decrease of tear sCD14 expression when compared with healthy controls (0.58±0.27 a.u. vs 1±0.14 a.u., p<0.001). By comparing the different groups, patients with VKC in the active phase showed a significant decrease of tear sCD14 (0.45±0.2 a.u.) when compared with healthy subjects (p<0.001) and with both VKC group Q (0.87±0.16 a.u., p=0.005) and group R (1.1±0.13, p<0.001). VKC group Q and group R (1.1±0.16) did not show significant changes when compared with healthy controls. (Figure 1A).
Conjunctival epithelium expression of CD14 showed similar results. In fact, conjunctival CD14 expression was significantly decreased in patients with VKC when compared with healthy subjects (0.7±0.29 a.u. vs 1±0.1 a.u., p=0.013). Patients with VKC group A showed significant decrease of conjunctival CD14 (0.49±0.14 a.u.) when compared with healthy subjects (p=0.001) and with VKC in both group Q (1.02±0.58 a.u., p<0.001) and R (1.18±0.02 a.u., p<0.001). Patients with VKC in the quiescent phase and after VKC recovery did not show significant difference in conjunctival expression of CD14, when compared with healthy controls. (Figure 1 B)
Conjunctival epithelium expression of TLR-4 was significantly decreased in patients with VKC when compared with healthy controls (0.4±0.27 a.u. vs 1.06±0.07 a.u., p<0.001), while conjunctival expression of TLR-9 did not show significant changes (0.82±0.4 a.u. vs 1±0.12 a.u.). VKC patients in the active phase showed a significant decrease of both TLR-4 and TLR-9 when compared with healthy controls (TLR-4: 0.17±0.03 a.u., p=0.028; TLR-9: 0.54±0.08 a.u., p=0.011) and with VKC group Q (TLR-4: 0.65±0.12 a.u., p=0.004; TLR-9: 1.3±0.12 a.u., p<0001) and VKC group R (TLR-4: 0.5±0.18 a.u, p=0.035; TLR-9: 1.1±0.08 a.u., p<0.001). (Figure 2 A, B)
VKC in the quiescent phase showed significant decrease of conjunctival TLR-4 when compared with healthy controls (p=0.010) while TLR-9 was significantly increased (p=0.025). VKC group R showed significant decrease of TLR-4 (p=0.005) when compared with healthy subjects while TLR-9 did not show significant changes.
In patients with VKC, the higher papillary reaction score was significantly correlated with the lower expression of tear sCD14 (p=0.005, R=-0.779), and of conjunctival CD14 (p=0.049, R=-0.668), TLR-4 (p=0.015, R=-0.850) and TLR-9 (p=0.001, R=-0.891). Conjunctival hyperemia scores were also significantly correlated with tear sCD14 expression (p=0.044, R=-0.767).
No significant difference were found between patients with vs without other allergic diseases (tear sCD14: 0.63±0.29 a.u vs 0.75±0.36 a.u; conjunctival CD14: 0.75±0.34 a.u vs 0.79±0.37 a.u, TLR-4: 0.43±0.30 a.u vs 0.38±0.22 a.u, TLR-9: 0.88±0.42 a.u vs 0.82±0.35 a.u; respectively)
Six out of nine patients in the active group were treated with topical Hydrocortisone 4 times daily and were evaluated after 7 days. All patients showed improvement of signs and symptoms, with absence of conjunctival hyperemia and corneal involvement and mild to absent ocular symptoms. With except of tear sCD14 (0.48±0.17 a.u vs 0.51±0.16 a.u), all the biological parameter evaluated showed decrease of conjunctival expression however, only TLR-4 reached significant values when compared with baseline (TLR4: 0.18±0.11 a.u vs 0.09±0.03 a.u, p=0.035; CD14: 0.46±0.1 a.u vs 0.29±0.17 a.u, TLR-9: 0.5±0.06 a.u vs 0.31±0.13). (Figure 3)