To the Editor:
Cryopyrin-associated periodic fever syndrome (CAPS) is a group of genetic diseases consisting of familial cold autoinflammatory syndrome (FCAS) and presenting with urticaria triggered by cold, Muckle-Wells syndrome (MWS) with fever, hearing loss, rash and joint pain, and neonatal onset multisystem inflammatory disease (NOMID), a severe neonatal disease. CAPS is associated with mutations in the NLRP3 gene1,2. NLRP3 associates with the proteins ASC and pro-caspase 1 to form the NLRP3 inflammasome, which is important for activation of pro–inter-leukin 1β (IL-1β) to mature IL-1β. Consequently, CAPS can be treated with anti-IL-1β therapy. Some patients with more diffuse inflammatory symptoms together with NLRP3 mutations have been classified as “atypical” CAPS3. We describe a patient with inflammatory symptoms fulfilling criteria of adult-onset Still disease (AOSD) but with a genotype typical of CAPS.
A 32-year-old man with previously known thrombophlebitis related to activated protein C resistance presented in May 2009 with sore throat, relapsing fever above 39°C especially in the afternoon, cervical adenitis, and transient maculopapular exanthema. C-reactive protein (CRP) was 192 mg/l, leukocyte count 11.3 × 109/l (ref < 8.8), neutrophils 8.2 × 109/l, aspartate aminotransferase 1.6 μkat/l (ref < 0.76), alanine aminotransferase 2.5 μkat/l (ref < 1.2), and lactate dehydrogenase 9.7 μkat/l (ref < 3.5). …
Address correspondence to Dr. P. Eriksson, Department of Rheumatology, University Hospital, 581 85 Linköping, Sweden. E-mail: per.eriksson{at}lio.se