Parvovirus B19-associated haemophagocytic syndrome with prominent neutrophilia.

We describe a patient with both haemophagocytic syndrome and acute myocarditis probably associated with parvovirus B19 infection. The patient had a marked neutrophilia instead of neutropenia more usually observed in virus-associated haemophagocytic syndrome (VAHS). Endogenous serum concentrations of macrophage colony-stimulating factor (M-CSF), granulocyte colony-stimulating factor (G-CSF), and tumour necrosis factor-alpha (TNF-alpha) were higher than normal, suggesting that these cytokines may be involved in the genesis of the observed syndrome.