Conditional Autoantibodies in Urticaria Patients: A Unifying Hypothesis

Chronic urticaria may be characterized by conditional autoantibodies against the α-chain of the high-affinity receptor for IgE (FceRI). These autoantibodies are termed conditional as they only recognize unoccupied FceRI. The same conditional reactivity pattern has also been found in sera of atopic and normal healthy donors. Any condition resulting in accessibility of FceRI will render these autoantibodies anaphylactogenic. This finding offers a unifying hypothesis for the manifestation of different forms of urticaria. Non-immunologic triggers may thereby influence directly or indirectly the number of accessible FceRI allowing the conditional autoantibodies to induce urticaria symptoms.