Successful IVIG treatment of human parechovirus-associated dilated cardiomyopathy in an infant.

Human parechoviruses (HPeVs) are closely related to human enteroviruses and exhibit many similarities in disease spectrum and symptoms. HPeV1 is most commonly associated with mild disease, but rare associations with severe disease such as myocarditis have been reported. Currently, no treatment is available for severe HPeV infections. In this case report we describe an infant with a severe, dilated cardiomyopathy in whom HPeV1 was revealed to be the only identifiable cause. The infant was treated with intravenous immunoglobulins (IVIGs) and recovered completely. In vivo blood samples revealed a high HPeV1 antibody titer after treatment with IVIGs. In vitro IVIGs contained high titers of neutralizing antibodies against HPeV1. Our hypothesis is that patients with myocarditis caused by viruses with a high prevalence in the population and hence high antibody titers in IVIGs are likely to benefit from treatment with IVIGs. More research combining virological and clinical data is needed to see whether this hypothesis is true.