Evolution of previous sarcoidosis under type 1 interferons given for severe associated disease

Sarcoidosis is a granulomatous disorder with a well-known T helper (Th) type 1 cell commitment and a key pathogenic role of interferon (IFN)-gamma. However, little is known about the influence of type 1 IFNs, such as IFN-alpha and IFN-beta, on the course of previous sarcoidosis. The aim of this study was to determine whether type 1 IFNs can safely be used in patients with sarcoidosis for severe associated disease. The present study examined a series of four patients with sarcoidosis, treated by IFN-alpha or IFN-beta for viral hepatitis (three cases) or multiple sclerosis (one case). IFN was initiated soon after apparent recovery (three cases) or during a worsening phase of sarcoidosis (one case). Hydroxychloroquine was added in the case with active disease. Patients received interferon for 6-24 months and had close monitoring during and after IFN therapy. Interestingly, no recurrence or exacerbation of sarcoidosis had occurred at 4 yrs of follow up. Two patients were cured from viral hepatitis, whilst treatment for another failed. No neurological progression was observed in the remaining patient. This series suggests that, despite the T helper type 1 phenotype of sarcoid granulomatous reaction, type 1 interferons do not exacerbate sarcoidosis in remission and this makes their use possible if indicated. However, their effect in persistent forms of the disease needs further evaluation.