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

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

methodsMonocentric 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.

resultsEight 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%.

conclusionA 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.