Toward Personalized Medicine: The Utility of Enthesis and Joint Ultrasound Examination in Defining the Phenotype of Patients with Acute Anterior Uveitis

Background/Objectives: Patients with acute anterior uveitis (AAU) have a high prevalence of occult spondyloarthropathy (SpA). Only one previous study investigated ultrasonographic (US) changes at peripheral entheses and joints in patients with acute anterior uveitis (AAU) and no study has used these data in recognizing unknown SpA as defined by ASAS criteria. No previous study compared non-granulomatous (NGAU) with granulomatous uveitis (GAU) for these US features. The objective of this study was to investigate the prevalence of US enthesis and joint abnormalities in a consecutive series of GAU and NGAU patients and to use these data in recognizing unknown SpA as defined by ASAS criteria. Methods: A total of 152 consecutive patients diagnosed with AAU [103 NGAU (42 B27−, 61 B27+) and 49 GAU] from the Immunology Eye Unit (AUSL-IRCCS Reggio Emilia, Italy) were enrolled in this study. Six peripheral entheses as well as knee and ankle joints were bilaterally evaluated by US according to standard methods. The presence of any elementary lesion, structural damage and active enthesitis, according to OMERACT definitions, was recorded. ASAS classification criteria of SpA were integrated with the US data of active enthesitis and joint synovitis in defining the presence of enthesitis and arthritis. Results: NGAU patients had a higher prevalence of entheseal erosions (11.9% vs. 9%, P0 0.009), of enthesis exhibiting a PD signal (29.7% vs. 12.2%, p = 0.025) and of active enthesitis (23% vs. 8.2%, p = 0.026) compared with GAU group. Unknown SpA as defined by ASAS criteria was recognized in 29 patients by clinical and MR/Rx examination of sacroiliac joints and in 13 additional patients with the use of US data. Conclusions: Acute entheseal lesions and erosions are associated with NGAU, without apparent influence of HLA-B27 positivity. US examination helps to recognize previously unknown SpA and to define the disease phenotype of patients, moving toward more personalized treatment.