Correlation of Mantoux Test and Serum Angiotensin-Converting Enzyme (ACE) Levels with Clinically and Radiologically Diagnosed Ocular Tuberculosis and Ocular Sarcoidosis

Abstract

Abstract Aim: To evaluate the role of combined Mantoux test and serum angiotensin-converting enzyme (ACE) levels in the diagnosis of ocular tuberculosis (TB) and ocular sarcoidosis. Materials and Methods: A prospective and observational study including patients with bilateral granulomatous uveitis diagnosed both radiologically and clinically as ocular TB or ocular sarcoidosis within a six-month period. CT Thorax/CT abdomen was done, and findings were noted. Mantoux test and serum ACE levels were recorded, and findings were correlated. Results: The study included a total of 60 patients: 32 patients with ocular TB and 28 patients with ocular sarcoidosis. Using Mantoux test, 84.4% in the TB group tested positive and were correctly identified (sensitivity), and 96.4% in the sarcoid group tested negative and were correctly identified as sarcoidosis. Hence, the association between Mantoux test and diagnoses was statistically significant (P < 0.001). In the TB group, 25 subjects had normal and seven had elevated serum ACE levels. In the sarcoidosis group, 22 subjects had elevated and six had normal serum ACE levels. Hence, 78.1% were correctly identified with normal serum ACE levels (sensitivity) in the TB group and 78.6% were identified with elevated serum ACE levels in the sarcoidosis group, and the proportion difference was statistically significant (P < 0.001). Conclusion: Mantoux test and serum ACE levels are cost-effective investigations and can be used for the diagnosis of ocular TB and sarcoidosis when combined with clinical and radiological evidence. The combined use of serum ACE and Mantoux test is useful in differentiating between sarcoidosis and TB.