We describe 2 patients with prolonged autoimmune alterations following parvovirus B19 infection. B19 induced aplastic crises were the revealing manifestations of asymptomatic hemolytic conditions in the 2 patients: a Coombs' positive hemolytic anemia induced by D-penicillamine in the first and congenital spherocytosis in the second. Both patients had transient clinical and serological manifestations highly suggestive of systemic lupus erythematosus. In addition, prolonged clinical and serological remission of rheumatoid arthritis was observed in the first patient, while arthralgias, FANA, and anti-Ro antibodies persisted in the second, previously healthy patient. Our data suggest that parvovirus B19 infection may lead to chronic modulation of the autoimmune response in predisposed individuals.