Clinical study on the utility of allergy tests to detect IgE-mediated anaphylaxis after diclofenac etalhyaluronate administration

Objectives: This study was conducted to investigate factors involved in anaphylaxis related to diclofenac etalhyaluronate (DEH) [product name: Joyclu^® (JCL)] (containing DEH and macrogol 400), which is used to treat patients with osteoarthritis. Methods: Patients with osteoarthritis were divided into two groups that had (experienced patients) or had not experienced anaphylactic symptoms after JCL administration (nonexperienced patients). Five tests performed to assess factors related to anaphylaxis consisted of a skin prick test as the primary endpoint and the other tests including basophil activation test, allergen-specific IgE tests using enzyme-linked immunosorbent assay or immunochromatographic kits, and genetic study were secondary endpoints. Results: The skin prick test showed 4 (wheal)/7 (erythema) of 15 experienced patients and 0/3 of 19 nonexperienced patients were positive for any of the test reagents containing DEH. The basophil activation test showed two experienced patients were positive for test reagents containing DEH. DEH- and diclofenac-allergen-specific IgE were detected in 3 and 1 of 12 experienced patients, respectively. No clear results were shown in the other tests. Conclusions: DEH may be the main factor involved in the development of anaphylaxis. The skin prick test was more sensitive than the basophil activation and allergen-specific IgE tests for identifying factors associated with anaphylaxis.