Background and objectives Sarcoidosis is a multisystem disease of unknown aetiology characterised by a Th1 granulomatous immune response. Predicting need for treatment in sarcoidosis is based on well-recognised prognostic indicators.1 We aimed to interrogate a large cohort of sarcoidosis patients in order to identify novel predictors for treatment and disease progression defined physiologically and radiologically.
Methods Clinical data from 338 patients with sarcoidosis was recorded retrospectively including; age at diagnosis, gender, Scadding CXR stage at presentation, presence of Erythema Nodosum (EN), baseline inflammatory markers, immunoglobulin levels, skin prick testing (SPT), pulmonary function tests, BAL results and vitamin D levels. There was a minimum follow up of 2 years for all patients. The primary outcome measure was the need for treatment, defined as requiring oral corticosteroids for 6 months or more. Secondary outcome measures included need for steroid sparing agents and progression defined radiologically using scadding criteria or HRCT when available and assessing pulmonary function test decline.
Results Multivariate analysis and modelling of all presenting features was performed. Patients were characterised into four groups-limited no treatment, limited requiring steroids, chronic but stable and chronic progressive steroid dependent. Overall the treatment rate was 50.4% in this cohort. In the chronic cohort 32% required steroid sparing agents. Initial analysis confirmed previously known prognostic indicators including Scadding CXR stage, age >40 and presence of EN OR 0.24 (0.13–0.45), p < 0.0001 at diagnosis. Additional predictors of prognosis included IgG levels, positive skin prick testing and vitamin D levels. In the group with elevated levels of IgG (IQR 15.7–19.8) at assessment the treatment rate was 77.1% OR 3.3 (1.5 to 7.6) p value 0.004. In the group with positive SPT, only 17.4% required treatment, OR 0.21 (0.07–0.62), p value 0.005.
Conclusions These results indicate possible new markers of prognosis in terms of treatment and disease progression in sarcoidosis. Phenotyping sarcoid patients in this way may be valuable in designing future clinical trials in sarcoidosis.
Reference 1 Neville E, Walker AN, Geraint James D. Prognostic factors predicting the outcome of sarcoidosis: an analysis of 818 patients. QJM 1983;4:525–533