Diagnostic value of lymphopaenia and elevated serum ACE in patients with uveitis

Abstract

Aim: To evaluate the diagnostic worth of elevated serum ACE (sACE) and lymphopaenia, singly or combined, in diagnosing sarcoid uveitis.

Methods: Monocentric retrospective study, on a cohort of 996 adult patients referred to our department between March 2001 and December 2018 for a diagnostic work-up of uveitis. The sensitivity (SE), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of the two biomarkers were calculated in different contexts.

Results: Eight hundred and sixty-eight patient cases were reviewed. The mean age at uveitis onset was 49.4 (±18.6) years. Of them, 144 patients had a diagnosis of sarcoid uveitis. An elevated sACE had SE of 45.8%, Sp of 88.8%, PPV of 44.9% and NPV of 89.2% in diagnosing sarcoid uveitis. For lymphopaenia, SE was 15.3%, Sp was 96.7%, PPV was 47.8% and NPV was 85.2%. For the combination of elevated sACE and lymphopaenia, SE was 18.9%, Sp was 99.0%, PPV was 73.9% and NPV was 89.5%. The value of this combination varied according to patient age at diagnosis plus anatomoclinical entities: for patients aged ≤50 years, SE was 31.3%, Sp was 99.7%, PPV was 90.9% and NPV was 94.3%. For granulomatous uveitis, SE was 26.2%, Sp was 97.3%, PPV was 73.3% and NPV was 82.5%.

Conclusion: A combination of elevated serum ACE and lymphopaenia more convincingly suggests sarcoid uveitis than these investigational tests used alone, especially in patients with granulomatous uveitis, while a lack of these markers corresponds to a high NPV.

Trial registration number: NCT03863782.

Keywords: Diagnostic tests/Investigation; Inflammation.