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.

Local allergic conjunctivitis: a phenotype of allergic conjunctivitis.

PURPOSE: Local allergic rhinitis (LAR) has been reported in the field of otolaryngology; however, the concept of local allergic conjunctivitis (LAC) has not been widely studied in the ophthalmologic community. We routinely examined total IgE levels in tear fluids (t-tIgE) and antigen-specific IgE levels in serum (s-sIgE) in patients with suspected allergic conjunctivitis, on the basis of Japanese guidelines for allergic conjunctival diseases. There are several cases in which the results of t-tIgE and s-sIgE testing are divergent. We suggest that these divergent cases correspond to LAR in otolaryngology. METHODS: The study included 148 patients (33 men and 115 women) with clinical symptoms and signs of allergic conjunctivitis. Allerwatch Tear IgE® was used for measurement of t-tIgE levels. ImmunoCAP Rapid® and View Allergy 39® were used for measurement of s-sIgE levels. Conjunctival cytology using spatula was used to identify eosinophils on the conjunctiva. RESULTS: A total of 83 patients (56.1%) were positive and 65 patients were negative for t-tIgE in the AW. In the ICR, 97 patients (65.5%) were positive for at least one of the eight allergens, whereas 51 (34.5%) were negative for all allergens. Among 83 patients positive for t-tIgE, 14 (16.9%) had no detectable s-sIgE. Therefore, we considered the possibility of LAC in cases in which only local IgE could be detected. Among 28 cases (18.9%) who were negative for t-tIgE and s-sIgE, 21 underwent conjunctival scraping; eosinophils were found in four cases and eosinophilic granules in two. Accordingly, we considered the possibility of non-IgE-type AC in these six cases. CONCLUSIONS: These results suggest the existence of LAC that is a candidate of a phenotype of AC.

Microarray-based IgE detection in tears of patients with vernal keratoconjunctivitis.

BACKGROUND: A specific allergen sensitization can be demonstrated in approximately half of the vernal keratoconjunctivitis (VKC) patients by conventional allergic tests. The measurement of specific IgE in tears using a multiplex allergen microarray may offer advantages to identify local sensitization to a specific allergen. METHODS: In spring-summer 2011, serum and tears samples were collected from 10 active VKC patients (three females, seven males) and 10 age-matched normal subjects. Skin prick test, symptoms score and full ophthalmological examination were performed. Specific serum and tear IgE were assayed using ImmunoCAP ISAC, a microarray containing 103 components derived from 47 allergens. RESULTS: Normal subjects resulted negative for the presence of specific IgE both in serum and in tears. Of the 10 VKC patients, six resulted positive to specific IgE in serum and/or tears. In three of these six patients, specific IgE was found positive only in tears. Cross-reactivity between specific markers was found in three patients. Grass, tree, mites, animal but also food allergen-specific IgE were found in tears. Conjunctival provocation test performed out of season confirmed the specific local conjunctival reactivity. CONCLUSIONS: Multiple specific IgE measurements with single protein allergens using a microarray technique in tear samples are a useful, simple and non-invasive diagnostic tool. ImmunoCAP ISAC detects allergen sensitization at component level and adds important information by defining both cross- and co-sensitization to a large variety of allergen molecules. The presence of specific IgE only in tears of VKC patients reinforces the concept of possible local sensitization.

Allergen Testing: A Review of the Indications, Procedures, and Limitations in Ocular Allergy.

Allergen-based diagnostics are essential in the management algorithm of allergic diseases. Unlike systemic allergy, where the indications and interpretation of these diagnostic modalities are well established, their utility in ocular allergy is not well-defined. With the rising prevalence of ocular allergies and the need for personalized treatment strategies, there is a growing demand for precision allergen diagnostics. This review describes the commonly used tests with their indications, procedures, and limitations. A review of the literature was carried out on articles on allergen diagnostics in ocular allergy, and after excluding articles that were not relevant, 82 papers were included in the current review. IgE-mediated pathways contribute significantly to seasonal and perennial ocular allergy and partly to vernal keratoconjunctivitis. Most diagnostic techniques aim to detect IgE sensitization. In vivo tests include skin prick (SPT), intradermal, and patch tests. SPT is considered the gold standard and directly evaluates the presence of allergen-specific IgE in the skin. In vitro tests measure total and specific IgE from either tears or sera. Tear IgE measurement is relatively specific for allergic conjunctivitis and can provide insight into the potential allergens responsible for local sensitization. The conjunctival provocation test can help establish true allergy, especially in patients with polysensitization. This review also provides an overview of evidence in literature segregated based on the test employed. This includes 17 studies on only SPT; 42 studies on IgE measured in serum, tears, or both; and 20 studies which have evaluated both SPT and IgE. The pattern of allergen sensitization can guide recommendations for avoidance measures and immunotherapy. Thus, this could create a corticosteroid-sparing therapy avenue in these patients, reducing disease severity and resulting visual morbidity.