Relapsing pericarditis: Peripheral blood neutrophilia, lymphopenia and high neutrophil-to-lymphocyte ratio herald acute attacks, high-grade inflammation, multiserosal involvement, and predict multiple recurrences.

Peripheral blood neutrophilia and lymphopenia are typical of acute idiopathic pericarditis. Acute attacks of pericarditis are associated with neutrophilia and lymphopenia, as compared with disease remission. During acute attacks, neutrophilia and lymphopenia reflect the extent of serosal inflammation and could help to customize therapeutic management after remission has been achieved.