Clinical investigation for the mechanisms of anaphylactic symptoms in osteoarthritis patients after diclofenac etalhyaluronate administration.

OBJECTIVE

This study was conducted to investigate the mechanisms of anaphylaxis in patients with osteoarthritis of the knee and hip after diclofenac etalhyaluronate [product name: JOYCLU® (JCL)] intra-articular injection and to determine the utility of tests to investigate the mechanism involved.

METHODS

In this observational study in Japan, patients aged ≥20 years with knee or hip osteoarthritis who received JCL intra-articular injection experienced anaphylactic symptoms considered related to JCL ('experienced patients') or did not experience allergic symptoms considered related to JCL ('non-experienced patients'). Basophil activation tests (BATs), specific immunoglobulin E (IgE) antibody testing by enzyme-linked immunosorbent assays (ELISAs) or immunochromatographic kit, and genome-wide association studies (GWASs) were conducted using patient blood and saliva.

RESULTS

Thirteen experienced patients and 14 non-experienced patients were tested. Seven experienced patients tested positive by BAT using diclofenac etalhyaluronate-containing test substances. Diclofenac-specific IgE antibodies were detected in four of seven BAT-positive patients but not in the non-experienced patients. Specific IgE antibody testing by immunochromatographic kit and genome-wide association study showed no clear results.

CONCLUSIONS

These findings suggest that anaphylaxis occurs after JCL administration via an IgE-mediated mechanism and that diclofenac etalhyaluronate may be involved in this mechanism. BAT and diclofenac -specific IgE enzyme-linked immunosorbent assay may be useful tests for investigating the mechanisms of anaphylactic reactions after JCL administration.