Life-threatening human herpes virus-6 infection in early childhood: presenting symptom of a primary immunodeficiency?

Hennus, Marije P; van Montfrans, Joris M; van Vught, Adrianus J; Tesselaar, Kiki; Boelens, Jaap-Jan; Jansen, Nicolaas J

OBJECTIVE To report two previously healthy children with a life-threatening course of human herpes virus type 6 (HHV-6) infection and prolonged pediatric intensive care treatment. DESIGN Case reports. SETTING A 16 bed pediatric intensive care unit at a tertiary care children's hospital. PATIENTS Two children with life-threatening HHV-6 disease. INTERVENTIONS Both children were mechanically ventilated because of respiratory failure. A detailed viral and immunologic workup was performed and treatment with antiviral medication started. MEASUREMENTS Polymerase chain reaction assays of plasma, cerebrospinal fluid, bronchoalveolar lavage, and lung biopsies yielded HHV-6 in both patients. Immunophenotyping and lymphocyte stimulation tests with both mitogens and antigens indicated an immunodeficiency in both patients. CONCLUSION HHV-6 infection should be considered in infants and young children with respiratory failure or meningo-encephalitis without clear causative agent or failure to respond to empirical treatment. A thorough immunologic workup and early start with antiviral therapy in any patient with a life-threatening course of HHV-6 infection is mandatory, because a severe HHV-6 infection can be the first indication of a primary immunodeficiency.