Lymphocyte transformation in patients with cobalt dermatitis

Area of Science:

• Immunology
• Dermatology
• Allergy

Background:

• Cobalt allergy is a common cause of allergic contact dermatitis.
• Diagnosing cobalt allergy often relies on patch testing, but further in vitro confirmation can be beneficial.

Purpose of the Study:

• To evaluate the utility of a lymphocyte transformation test (LTT) using cobalt chloride for diagnosing cobalt-induced contact dermatitis.
• To determine if LTT can differentiate between patients with strongly and weakly positive cobalt patch tests and healthy controls.

Main Methods:

• A lymphocyte transformation test was conducted on 14 patients with cobalt-positive patch tests and dermatitis, and 9 controls.
• Cobalt chloride at a 1:5000 dilution in RPMI-1640 medium was used as the stimulant.
• Responses were compared to mitogens (phytohaemagglutinin, pokeweed mitogen, concanavalin A) and recall antigens (purified protein derivative, Candida albicans).

Main Results:

• Patients with strongly positive cobalt patch tests showed significantly higher lymphocyte transformation compared to controls.
• No significant difference in lymphocyte transformation was observed between patients with weakly positive patch tests and controls.
• The chosen cobalt chloride dilution effectively distinguished between strongly reactive patients and controls.

Conclusions:

• The lymphocyte transformation test with cobalt chloride is a valuable tool for diagnosing cobalt-induced contact dermatitis, particularly in patients with strong positive patch test reactions.
• LTT may offer a more objective measure of cellular hypersensitivity to cobalt than patch testing alone.
• Further investigation is warranted for patients with weakly positive patch tests.