SAT0425 Phenotyping primary sjÖgren’s syndrome (PSS) by using salivary gland ultrasonography: a step forward to individualised therapies
Authors: C. Baldini, F. Ferro, N. Luciano, E. Calabresi, E. Elefante, V. Donati, M. Mosca, S. Bombardieri
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Salivary gland ultrasonography (SGUS) has recently appeared as a useful tool to non invasively assess major salivary glands inflammation and damage in primary Sjögren's syndrome (pSS). To date, relatively few studies have evaluated the usefulness of SGUS in characterising different disease phenotypes ultimately providing information on which patients might be most likely to benefit from specific interventions. <h3>Objectives</h3> to explore whether SGUS may be useful in identifying different clinical-serological and histopathological phenotypes of pSS, ultimately allowing individualised treatments. <h3>Methods</h3> Sonographic data were retrieved from a large monocentric cohort of pSS patients. The echostructure of each gland on B-mode images was graded on a 5-point scale (0–4), and a SGUS score ≥2 was defined as pathological. Hypo-anechoic areas in the glands were defined as isolated (&lt;25% of the surface), localised (25%–50%) and diffuse-scattered (&gt;50%). The biggest hypo or anechoic area in each gland was measured. SGUS was repeated in 150 pSS patients at least twice over a median follow up of 24 months. All the patients received a complete rheumatological assessment: disease activity was measured by the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI), histopathological evaluation included the assessment of the focus score (FS) and the reporting of the number of germinal centre (GC)-like structures. <h3>Results</h3> We included in this study 311 patients (300 F: 11 M; median age=58 years (IQR, 49–69)) and median disease duration of 3 years (IQR 0–9). Out of them 136/311 (43.7%) had a SGUS score &lt;2 with none or isolated hypo-anechoic areas in their glands. Localised areas were detected in 87/311 (28%) pSS patients and diffuse-scattered areas in 88/311 (28.3%). Patients with none or isolated hypo-anechoic areas tended to be older (p=0.06) and presented a significantly lower FS, a lower ESSDAI and a higher unstimulated salivary flow rate when compared to the other pSS patients (p&lt;0.001). Patients with localised or diffuse-scattered echographic pattern were more frequently seropositive for anti-Ro/SSA, anti-La/SSB and rheumatoid factor, presented more frequently hypergammaglobulinemia and low C3/C4 levels and had a higher frequency of GC-like structures in their biopsies (p&lt;0.001). Patients with diffuse-scattered hypo-anechoic areas presented the highest disease activity, in particular in the ESSDAI glandular, cutaneous and haematological domains. Notably, the SGUS score did not change over the time in patients who underwent repeated SGUS evaluations. Out of 136 patients with a SGUS score &lt;2, 58 underwent additional SGUS evaluations over the follow-up. The SGUS was unchanged in all the cases and still associated with a low systemic disease activity. <h3>Conclusions</h3> This study highlighted the potential usefulness of SGUS in phenotyping pSS subsets. Patients with none or isolated hypoechoic areas in their glands are likely to present a low systemic disease activity during the disease course, being therefore candidate to less aggressive treatments. By contrast, patients with highest SGUS scores tend to present a more active systemic involvement and are candidate to receive a more aggressive therapy. <h3>Disclosure of Interest</h3> None declared