Sarcoidosis is an inflammatory disease characterized by small nodules (granulomas) of immune cells. The granulomas can occur in virtually any organ, but the lungs are the predominant site. Sarcoidosis looks similar to tuberculosis, some fungal infections, and chronic beryllium disease. These possibilities must be ruled out before sarcoidosis is diagnosed. About 1.3% of women will experience sarcoidosis sometime in their lives. The majority of cases last 12 – 36 months, while more serious cases persist for up to 5 years, and a few last for decades.
The cause of sarcoidosis is not well understood. Various antigens are thought to trigger an exaggerated immune response in genetically susceptible individuals. Young and middle-aged adults are most at risk. A recent study at the University of Pennsylvania identified mold, musty odors, and insecticides as environmental factors that may trigger the disease. A research team in Belgium reported that interferon, used to treat conditions including hepatitis C, induces the development of several immune diseases, including sarcoidosis.
The main treatment option is corticosteroids. Other drug options include antimalarials, aminoquinolins, methotrexate, azathioprine, cyclophosphamide, and thalidomide. Current research suggests the use of tumor necrosis factor inhibitors for some patients. These include infliximab (Remicade), adalimumab (Humira), and etanercept (Enbrel). These are all biologics (proteins) which are FDA approved to treat rheumatoid arthritis and similar autoimmune conditions. They all have serious potential side effects, including lymphoma and other cancers. These drugs reduce the body's ability to fight infection. The FDA strengthened its requirements for warnings about opportunistic fungal infections in September 2008 after reports of several deaths. In addition, a recent article reports that a patient developed sarcoidosis during etanercept therapy for rheumatoid arthritis. However, a review article in the medical literature in December 2008 recommended the use of tumor necrosis factor inhibitors for selected patients with chronic sarcoidosis. See Reference 5.
Other treatments recommendations include low calcium diet and avoidance of sunlight exposure. The probability of spontaneous healing is reported as 55 – 90% for stage I sarcoidosis; 40 – 70% for stage II; 10 – 20% for stage III, and 0% for stage IV (overt lung fibrosis).
by Linda Fugate, Ph.D.
References:
1. Nunes H et al, “Sarcoidosis”, Orphanet Journal of Rare Diseases 2007;2:46.
2. Rossman MD et al, “HLA and environmental interactions in sarcoidosis”, Sarcoidosis Vasc Diffuse Lung Dis. 2008 Dec;25(2):125-32.
3. Froidure A et al, “Multisystemic sarcoidosis associated with a second therapy for chronic hepatitis C”, Acta Gastroenterol Belg. 2009 Apr-Jun;72(2):249-51.
4. Ishiguro T et al, “Development of sarcoidosis during etanercept therapy”, Intern Med. 2008;47(11)1021-5.
5. Baughman RP et al, “Inhibitors of temor necrosis factor (TNF) in sarcoisosis: who, what, and how to use them”, Sarcoidosis Vasc Diffuse Lung Dis. 2008 Dec;25(2):76-89.
6.http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/DrugSafetyInformationforHeathcareProfessionals/ucm174474.htm
7.http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2008/ucm116942.htm