A preliminary study conducted by a team at the National Institutes of Health has identified a promising new treatment in children for the most common form of a rare disorder. The syndrome is called periodic fever associated with aphthous stomatitis, pharyngitis and cervical adenitis - or PFAPA - and is characterized by monthly flare-ups of fever, accompanied by sore throat, swollen glands and mouth lesions.
The proposed treatment, which will be validated in a larger study before it is recommended in treating PFAPA syndrome, wards off an inappropriate immune system attack without increasing the frequency of flare-ups, a problem caused by the current standard treatment with corticosteroids. The team of researchers from the National Human Genome Research Institute (NHGRI) and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) reported their findings in the April 8, 2011, early online edition of the Proceedings of the National Academy of Sciences.
"Until now, the basis of PFAPA has been a mystery," said senior author and NHGRI Scientific Director Daniel Kastner, M.D., Ph.D. "Advances in genomic analysis have allowed us to define a major role for the innate immune system, the body's first line of defense against infection. Targeting a specific product of white blood cells at the first sign of fever appears to abort the attacks."
Children with PFAPA syndrome experience attacks of fever, each lasting three to six days, usually three to eight weeks apart. Their predictability is so regular that parents have been known to make pediatric appointments a week ahead of when they expect their child to experience a PFAPA episode. Affected children experience their first attack before the age of 5, with fever episodes usually abating in adolescence or young adulthood. The only remedy for PFAPA, besides corticosteroids, is removal of an affected child's tonsils, which has a good rate of success in eliminating PFAPA syndrome, but is an invasive alternative.
The new experimental treatment resulted from the researchers using a systems biology approach, which entailed gene and protein expression and cell biology analysis in carefully selected patient and healthy control subjects, to determine the underlying disturbance of the immune system. They analyzed patient blood samples to detect which gene and protein networks are involved in the cell signaling and metabolic pathways activated in the disease.
The research group studied 21 patients with PFAPA syndrome along with an equal number of healthy children and 12 children with a distinctly different set of hereditary fever syndromes. They analyzed gene expression during episodes of fever and intervening periods when the children were well. The analysis revealed gene expression profiles that uniquely identified PFAPA immune response.
"Gene profiles during PFAPA flares are remarkably distinct from when children are asymptomatic," said Dr. Kastner, noting that the analysis also distinguished PFAPA syndrome from other periodic fevers. But when PFAPA patients are asymptomatic, their gene expression is similar to healthy children.