Distinctive Inflammatory Traits of Parvovirus B19 Infection Associated with Persisting Autoimmunity.

BACKGROUND

Adult parvovirus B19 (B19V) infection occurs with cyclic outbreaks and can be associated with inflammatory manifestations mimicking or heralding the onset of systemic autoimmune diseases. Little is known about clinical traits distinguishing patients with transient vs. persisting manifestations.

METHODS

Leveraging data from the 2024 B19V infection outbreak, we set up a retrospective, multicentre, observational study investigating the epidemiology and clinical phenotypes of patients with B19V infection presenting to tertiary care for immune-mediated manifestations, including patients with pre-existing autoimmunity.

RESULTS

A total of 39 B19V infections were identified, yielding an annual incidence of 1.78 cases/1000 patients. Autoimmune rheumatic diseases were pre-existing in 7/39 and newly diagnosed in 5/39. One patient was hospitalised. Arthritis was more frequent in new-onset (89%) than in pre-existing (14%; p = 0.010) or no autoimmunity (19%; p < 0.001). Anaemia was not found in patients with pre-existing autoimmunity in contrast to those with new autoimmune disease diagnoses (40%; p = 0.039) or transient manifestations (52%; p = 0.013). Skin manifestations were numerically less frequent in this latter group (56%) than in patients with pre-existing (100%) or newly onset autoimmunity (80%). Autoantibodies were detected in 44% of cases and were more frequent in patients with constitutional symptoms but were not confirmed in the long term in most cases. Glucocorticoids were more frequently employed in patients with new-onset rather than pre-existing autoimmune diseases (p = 0.006) or without chronic autoimmunity (p = 0.027).

CONCLUSION

B19V-associated new-onset autoimmunity may occur in one in six cases observed in tertiary immunology care, show distinct clinical features, and require significant immunosuppression.