Complement C4 deficiency and HLA homozygosity in patients with frequent intraoral herpes simplex virus type 1

M Seppänen1, M L Lokki, T Timonen

  • 1Department of Medicine, Division of Infectious Diseases, Helsinki University Central Hospital Helsinki, Finland. mikko.seppanen@hus.fi

Three consecutive patients with no apparent immunodeficiency who had frequent intraoral herpes simplex type 1 recurrences, a rare complication of herpes simplex virus infection, were found to have a total deficiency of either the A or B isotype of the complement component C4 and to be homozygous for the studied HLA antigens. A combination of HLA homozygosity, which may lead to impaired T cell recognition of viral peptides, and deficiency in the classical complement pathway, which can compromise virus neutralization, may predispose to severe and frequent herpes simplex virus infections.

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