Aims To investigate the hypothesis that lymphopenia is an independent predictor of sarcoidosis in new patients presenting with uveitis.

Patients and methods Retrospective case–control study of 112 patients with sarcoidosis-associated uveitis (SAU) against 398 controls with other forms of uveitis.

Results Of the patients with SAU, 30/112 (26.8%) had significant lymphopenia (<1.0×10⁹/L), compared with 24/398 (6.0%) for other uveitis (p≤0.0001, OR 5.7 (95% CI 3.2 to 10.3)). The mean lymphocyte count for patients with SAU was 1.43 vs 2.04 for other uveitis (p≤0.0001). Logistic regression modelling using diagnosis of SAU as the independent variable identified age, ACE levels and lymphocyte count as independent predictors of SAU. A new patient with uveitis with significant lymphopenia has a risk of sarcoidosis (from this parameter alone) of 31.6%.

Conclusions Significant lymphopenia (<1.0×10⁹/L) is an independent predictor of sarcoidosis in new patients presenting with uveitis. We recommend that diagnostic criteria for SAU should be modified to include this phenomenon.