Contribution of the Leukocyte Adherence Inhibition Test to the Diagnosis of Immunoreactivity against Cobalt

Aims: To evaluate the potential of the Leukocyte Adherence Inhibition Test (LAIT) as a tool for evaluating immunoreactivity against cobalt in patients with clinical suspicion of cobalt hypersensitivity.

Study Design: We retrospectively examined the medical charts of a population of 97 patients diagnosed with Allergic Contact Dermatitis (ACD) and/or dyshidrotic eczema (DE) with clinical suspicion of cobalt hypersensitivity who were investigated with an ex vivo challenge monitored by LAIT against CoCl₂·6H₂O.

Place and Duration of Study: Instituto Alergoimuno de Americana – São Paulo – Brazil – between January 2018 and June 2023.

Methodology: The percentage of Leukocyte Adherence Inhibition (LAI) promoted by the ex vivo challenges with CoCl₂·6H₂O was distributed in ranges through Cascade Distribution Charts to observe the variability of the results.

Results: The LAI mean was 44.8%, SD 26.9%, range 0% to 94%, mode = 0% (appeared 14 times). There was a wide range of distribution of LAI results, suggesting that some patients had immunoreactivity against cobalt, while others do not.

Conclusion: Our preliminary results support the fact that the LAIT performed with CoCl₂·6H₂O may differentiate diverse degrees of ex vivo immunoreactivity against cobalt in allergic patients.