title: Virus-induced interferon production in leukocyte cultures from children with recurrent respiratory infections. A follow-up study.
abstract: BACKGROUND
  Lowered yields of virus-induced interferon (IFN) by leukocyte cultures were previously suggested to be associated with recurrent respiratory infections in children (Pitkaranta et al. (1993) Clin. Diagn. Virol. 1, 101-108).
  
  
  OBJECTIVE
  To investigate if the observed lowered IFN producing capacity was secondary to the underlying disease and, consequently, would be normalized after recovery of the child from the chain of infections.
  
  
  METHODS
  Forty-eight 3-12-year-old children suffering from recurrent upper respiratory tract infections (acute otitis media included) were followed-up for 2 years. Their clinical condition and virus-induced interferon production in cultures of peripheral blood leukocytes were examined at the beginning and end of this period.
  
  
  RESULTS
  In 24 children the health improved strikingly during the follow-up, in 12 children a mild improvement took place, while 12 children remained constantly ill. IFN yields in cultures stimulated with corona- and respiratory syncytial viruses improved along with the clinical situation of the children. Parallel cultures induced with adeno-, influenza A or rhinoviruses did not show a similar correlation.
  
  
  CONCLUSIONS
  These results suggest that the relationship between interferon production by leukocyte cultures and recurrent infections is complex and may be virus-specific.
authors.affiliation: Department of Otolaryngology, University of Helsinki, Haartmaninkatu 4, 00290 Helsinki, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Pitkäranta
authors.forename: P
authors.initials: P
authors.lastname: Karma
authors.forename: T
authors.initials: T
authors.lastname: Hovi