Is colchicine more effective to prevent periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis episodes in Mediterranean fever gene variants?

BackgroundPeriodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is the most frequent repetitive fever syndrome in childhood. It is characterized by fever episodes lasting for approximately 3-6 days, once every 3-8 weeks. MethodsClinical and laboratory data for PFAPA syndrome patients between January 2010 and December 2014 followed up at a tertiary pediatric care hospital were reviewed. ResultsFour hundred children (256 male, 144 female; mean age at diagnosis, 4.2 2.2 years), were enrolled in the study. During the episodes, mean leukocyte number was high (12 725/mm(3)) with predominant neutrophils. The mean number of monocytes was 1256/mm(3), and 90.2% had monocytosis. Serum amyloid A and C-reactive protein were high in 84.6% and in 77.8% of the patients, respectively. Mediterranean fever (MEFV) gene heterozygous mutation was identified in 57 of the 231 patients (24.7%) in whom genetic analysis had been performed. The most frequent mutation was heterozygous M694V (10%, n = 23). Extension of between-episode interval following prophylaxis was noted in 85% of those on regular colchicine treatment (n = 303). In the colchicine group, between-episode interval was prolonged from 18.8 +/- 7.9 days (before colchicine treatment) to 49.5 +/- 17.6 days on prophylactic colchicine therapy; also, prophylactic treatment was more effective in reducing episode frequency in patients with MEFV gene variant (n = 54, 96%) than in those without (n = 122, 80%; P = 0.003). ConclusionsThis study has involved the largest number of PFAPA syndrome patients in the literature. It is particularly important to assess and to demonstrate the high rate of response to colchicine prophylaxis in PFAPA syndrome patients, especially those with MEFV variant. On blood screening, neutrophilia associated with monocytosis and low procalcitonin could contribute to diagnosis.