Relationship among total tear IgE, specific serum IgE, and total serum IgE levels in patients with pollen-induced allergic conjunctivitis

Background Recently, the number of patients with pollinosis, particularly Japanese cedar pollinosis, has markedly increased. We previously reported about local allergic conjunctivitis, which is a phenotype of allergic conjunctivitis (AC). AC cases are often sensitized by various antigens. This study aimed to investigate the relationship among total tear IgE (t-tIgE), specific serum IgE (s-sIgE), and total serum IgE (t-sIgE) levels in patients with pollen-induced AC. Methods In 2019, 1372 patients were clinically diagnosed with AC at the Yamana Eye Clinic using t-tIgE, t-sIgE, and s-sIgE tests against 39 allergens. Among the pollen-induced AC patients who underwent allergen testing, 99 tested positives for s-sIgE against pollen. The subjects comprised 33 (33.3%) male and 66 (66.7%) female individuals aged 9–86 years. Results The t-tIgE test was positive in 68 (68.7%) patients and negative in 31 (31.3%) patients. In the t-sIgE test, 45 (45.5%) patients had t-sIgE levels above the reference value of 170 IU/mL. The higher the total score of the positive class value of each pollen-specific IgE (pollen-sIgE) antibody, the higher the positive rate of t-tIgE (p < 0.001). Of 32 patients in whom food-specific IgE (food-sIgE) was detected, 81.3% of the pollen-sIgE-positive and food-sIgE-positive cases were also positive for t-sIgE and t-tIgE. However, significant difference was not found between the total score of food-sIgE of the t-tIgE positive group and negative group. Conclusions Pollen-induced AC is caused by pollen sensitization of the conjunctiva. Food-induced AC might be induced by the different pathological mechanism involved in pollen-induced AC.

Serum Concentrations of Antigen-Specific IgG4 in Patients with Japanese Cedar Pollinosis

Purpose: To elucidate the usefulness of Japanese cedar pollen (JCP)-specific antigen-specific immunoglobulin (IgG) 4 as a biomarker for predicting the efficacy of sublingual immunotherapy for cedar pollen-induced allergic rhinitis. Methods: We divided a total of 105 cases with Japanese cedar pollinosis into three groups: “SLIT Successful,” SLIT Unsatisfactory,” and “SCIT” groups. The SLIT group patients were treated with JCP Droplet (Torii Pharmaceutical Co. Ltd., Tokyo, Japan) for one year from 2015 and were divided into two groups, the SLIT Successful group or the SLIT Unsatisfactory group. The SLIT Successful group (n = 16) were subjects treated by SLIT only, who were able to experience control of their naso-ocular symptoms without the need for antiallergic rescue agents during the peak season of atmospheric pollen. The SLIT Unsatisfactory group (n = 76) comprised subjects treated with SLIT only, who did not respond successfully, and were administered with rescue agents to control their naso-ocular symptoms. The SCIT group had been treated with standardized JCP extract (Torii Pharmaceutical Co., Ltd., Tokyo, Japan) for three years from 2012, and were also able to experience control of their symptoms during the peak pollen season without the need for antiallergic rescue agents. We determined the serum level of JCP-specific immunoglobulin E (IgE), IgG, and IgG4 used in the 3gAllergy-specific IgE assay (3gAllergy). The serum levels of periostin and SCCA2 were measured using established ELISA procedures (clones SS18A and SS17B; Shino-Test, Japan) following the manufacturer’s instructions. We then made ROC curves for each group and assessed which index was best able to predict the efficacy of sublingual immunotherapy. Results: Serum JCP-specific IgE was significantly lower in the SCIT group than in the SLIT Successful group and the SLIT Unsatisfactory group (p < 0.05). Serum JCP-specific IgG was significantly higher in the SCIT group and the SLIT Successful group than in the SLIT Unsatisfactory group (p < 0.05). Serum JCP-specific IgG4 was also significantly higher in the SCIT group and the SLIT Successful group than in the SLIT Unsatisfactory group (p < 0.05). There was no significant difference among serum levels of periostin in the SCIT group, the SLIT Successful group, or the SLIT Unsatisfactory group. There was also no significant difference in SCCA2 among the three groups. In terms of ROC curves, a serum JCP-specific IgG4 value greater than 989.5 UA/mL showed the best sensitivity (93.3%) and specificity (94.7%) (p < 0.05) among other parameters. Conclusions: The serum JCP-specific IgG4 level is significantly correlated with the clinical efficacy of SLIT. Serum JCP-specific IgG4 cutoff levels greater than 989.5 UA/mL were correlated with an effective clinical response to SLIT, with a sensitivity of 93.3% and a specificity of 94.7%.