Cold agglutinin hemolytic anemia in a patient with adult-onset Still's disease.

We report on a patient with adult Still's disease who developed, at the onset of her illness, an autoimmune hemolytic anemia (AHA) due to cold agglutinin (CA). Hemolysis spontaneously subsided and CA disappeared before starting therapy with aspirin and prednisone. The occurrence of AHA in patients affected with collagen diseases is currently explained by a loss of tolerance, leading to the emergence of multiple autoreactive clones. In our case the self-limiting course of AHA leads us to propose another interpretation, i.e. that the cold reactive autoantibody might have been related to a transient infection able to play a pathogenetic role in the systemic disease, as suggested by several authors.