POS0123 MAJOR SALIVARY GLAND ULTRASONOGRAPHY AND MRI WITH DIFFUSION WEIGHTED IMAGING (DWI) AS COMPLEMENTARY TOOLS TO IDENTIFY FEATURES OF MALT IN PRIMARY SJÖGREN’S SYNDROME (pSS): A SINGLE CENTER CROSS SECTIONAL STUDY

Background

Salivary MALT lymphoma represents the major complication of primary Sjögren’s Syndrome (pSS). However, the early recognition of MALT lymphoma may be challenging due to its indolent, slow clinical course.

Objectives

1. to identify salivary gland ultrasonographic (SGUS) features and magnetic resonance (MRI) abnormal findings with Diffusion Weighted Imaging (DWI) and Apparent Diffusion Coefficient (ADC) of MALT in pSS patients 2. To evaluate the correlation between salivary gland ultrasonography (SGUS) and MRI in pSS patients with suspected lymphoma.

Methods

consecutive patients with pSS (2016 ACR/EULAR criteria) and suspected MALT lymphoma undergoing histological examination were included in this cross sectional study from September 2017 to November 2021. The US echostructure of each gland on B-mode images was graded using the latest 2019 OMERACT semiquantitative SGUS scoring systems (0-3). Sonographic features of focal lesions were described. Conventional MRI techniques (i.e T1WI, T2WI, and STIR images) combined with MR sialography was performed in all the cases. DWI was acquired at b-value 0, 500 and 1000. ADC values were calculated. Patients’ clinical and histological data were collected. Data were presented as mean±SD, or percent frequency as appropriate. Intergroup comparisons were made using the t-test/Mann–Whitney test for continuous variables and Fisher’s exact test for categorical variables.

Results

45 pSS (mean age, S.D=55±15 yrs) were included. MALT lymphoma was histologically confirmed in 14/45 pSS patients and, specifically in 18/180 major salivary glands (17 parotids and 1 submandibular glands). At SGUS examination, MALT salivary glands presented an OMERACT grade 3 in 16/18 and a grade 2 in 2/18, significantly higher than the OMERACT scoring observed in no-MALT pSS glands (p=0.0001). The sonographic features more commonly detected in MALT were: hypoecoich macroareas with posterior enhancement, presence of septa or hyperechogenic strands and anarchic intralesional vascularization. At MRI, 15/18 (83.3%) MALT lymphoma appeared as intraglandular solid lesions: 9/15 (60%) were solid-cystic lesions and 6/15 (40%) were solid lesions without cystic changes. The frequency of solid lesions in pSS patients without lymphoma was 3/124 (2.4%), significanlty lower than in MALT-pSS. Furthermore 15/18 (83.3%) MALT lymphoma showed glandular fatty substitution. The presence of fatty substitution did not differ in MALT lymphoma and in no-MALT pSS glands. The mean (SD) ADC value of MALT lesions was significantly lower than the ADC of the parotid glands in pSS without lymphoma (0.63±0.07 x 10^-3 mm2/s vs 1.13± 0.19 x 10^-3 mm2/s, p =0.001). A negative correlation between SGUS OMERACT score and mean glandular ADC values (r = – 0.776, p < 0.001) was found; patients with OMERACT score 3 presented the lowest mean salivary gland ADC when compared to the other OMERACT scores (0-2) (p=0.001).

Conclusion

OMERACT semiquantitative SGUS scoring systems and MRI with DWI represent promising complementary tools in the differential diagnosis of pSS MALT lymphoma, particularly useful to guide parotid biopsy. Patients with an OMERACT score 3 in their SGUS deserve a careful screening for lymphoma.

Disclosure of Interests

None declared

POS0778 ULTRA HIGH-RESOLUTION ULTRASOUND (UHFUS) OF LABIAL GLANDS IS A STRONG PREDICTOR OF SALIVARY GLAND HISTOPATHOLOGY IN SJÖGREN’S SYNDROME (PSS)

Background:

Last-generation ultra high-resolution ultrasound (UHFUS) transducers, producing frequencies up to 70 MHz and achieving tissue resolution up to 30 μm, are opening up new possibilities for the study of labial salivary glands (LSG) in patients clinically suspected with primary Sjögren’s syndrome (pSS).

Objectives:

To explore the value of LSG-UHFUS as a predictor of the intensity of the histological inflammation in LSG biopsy in an inception cohort of patients with sicca symptoms derived from daily clinical practice.

Methods:

Consecutive patients undergoing a LSG for clinically suspected pSS were included in this study from January 2018 to October 2020. UHFUS of LSG was performed by using VEVO MD, equipped with a 70 MHz probe, scanning first the central compartment of the inferior lip, and then both peripheral compartments. Parenchymal homogeneity was graded on a scale of 0 (normal) to 3 (evident). UHFUS imaging was used to locate the LSG for the US-guided biopsy. For each of the LSG specimens the area of the glandular tissue, the presence and number of foci and the focus score (FS) were assessed. Immunostaining for CD21 was performed to evaluate the presence of follicular dendritic cells (FDC) in foci.

Results:

We included a total of 171 patients with suspected pSS: out of them, 83 (48.5%) received a diagnosis of pSS (ACR 2016 criteria) and 88 (51.5 %) were diagnosed as no-SS sicca controls. Out of the 171 LSG biopsies, 73/171 (42.7%) were characterized by a nonspecific chronic sialadenitis (NSCS) whereas a focal lymphocytic sialadenitis (FLS) was described in the remaining 98/171 (57.3%). UHFUS-LSG scores were differently distributed in pSS patients with respect to no-SS sicca controls: a score 0 was detected in 16/88 no-SS sicca controls and in none of the 83 pSS patients, whereas a score 3 was detected in 12/83 pSS and in none of no-SS sicca controls. (p<0.001). The higher was the UHFUS grading, the higher was the number of foci (from a mean (S.D) = 0.38 (0.72) in UHFUS-score 0 to 4.58 (3.11) in UHFUS-score 3, p<0.001) and the focus score (from 0.17 (0.32) in UHFUS-score 0 to 1.88 (0.90) in UHFUS-score 3, p<0.001) of the samples. Overall, out of the 16 no-SS controls with LSG-UHFUS score 0, only 4/16 showed histological features of focal lymphocytic infiltrate; however, the mean FS of those 4/16 samples was 0.17 (0.32). In fact, considering a FS≥1, negative UHFUS-LSG was highly predictive of a negative histology (100 %). By contrast, out of the 12 pSS patients with the highest score at LSG-UHFUS (score 3), 10/12 presented FDC networks in their biopsies, with a positive predictive value of 83% of the severity of the infiltrate.

Conclusion:

UHFUS of LSG appeared feasible and sensitive in pSS; due to its striking negative predictive value this novel tool can help to identify negative patients on subsequent lip biopsy, thus avoiding invasive procedures in selected cases. Besides its diagnostic role, considering the association with the presence of FDC networks, UHFUS-LGS may also have a role in patients prognostic stratification.

Disclosure of Interests:

None declared

FRI0153 ULTRA HIGH-RESOLUTION ULTRASOUND (UHFUS) OF LABIAL SALIVARY GLANDS: POTENTIAL APPLICATIONS IN PRIMARY SJÖGREN’S SYNDROME

Background:

Major salivary gland ultrasonography has an established role in diagnosis and assessment of pSS. Nowadays, however, interest is also growing in last-generation ultra high resolution ultrasound (UHFUS) transducers, which can produce frequencies up to 70 MHz and achieve tissue resolution up to 30 μm, opening up new possibilities for the study labial salivary glands (LSG).

Objectives:

To investigate the usefulness of UHFUS in LSG ultrasound-guided biopsy and preoperative planning.

Methods:

Consecutive patients undergoing a LSG for clinically suspected pSS were included in this study from January 2018 to December 2019. UHFUS of LSG was performed by using VEVO MD, equipped with a 70 MHz probe, scanning first the central compartment of the inferior lip, and then both peripheral compartments. The following parameters were evaluated: distribution of the glands, parenchymal inhomogeneity (score 0-3, from normal to evident), and fibrosis. UHFUS imaging was used to help locate the LSG for the US-guided biopsy. The same expert pathologist calculated the surface area of gland sections examined, the LSG focus score (FS), the number of foci and evaluated the presence of ectopic germinal centers (GCs). Consecutive patients that had undergone a traditional LSG biopsy from December 2016 to December 2017 were included as controls.

Results:

We included a total of 249 patients with suspected pSS: 137 undergoing the UHFUS-guided LSGs and 112 the traditional LSG biopsy procedure. No demographic differences were observed between the two groups. No differences were also observed in the distribution of the final diagnosis. A diagnosis of pSS according the ACR 2016 criteria was made in 60/137 (43.8%) and 36/112 (32.1%) patients, respectively whereas a diagnosis of no-SS sicca was made in 44/137 (32.1%) and in 43/112 (38.4%) patients; the remaining diagnosis included secondary SS (4/137, 3% and 9/112, 8%) and undifferentiated connective tissue disease (UCTD) (29/137, 21.2%, and 24/112, 21.4%). With respect to no-SS sicca controls and UCTD patients, pSS patients presented higher UHFUS inhomogeneity scores in both central and peripheral labial compartments (p=0.001). There were no complications from the HUFUS-guided LSG biopsy. The mean glandular surface area obtained was significantly higher than the area obtained by traditional LSG biopsy procedure (7.4 ±4.0 mm2vs 6.3±3.7 mm2, p=0.02) thus facilitating the assessment of the FS. Interestingly, the latter showed a good correlation with the UHFUS inhomogeneity (r=0.509**, p=0.000).

Conclusion:

UHFUS of LSG appeared feasible and sensitive in pSS, potentially offering unique advantages in LSG ultrasound-guided biopsy.

Disclosure of Interests:

None declared

FRI0263 QUANTITATIVE MUSCLE ULTRASOUND IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES-A PRELIMINARY STUDY

Background:

Muscle involvement is the most frequent clinical feature in patients with idiopathic inflammatory myopathies (IIM). In addition to muscular enzymes, muscular magnetic resonance has been investigated for the assessment of disease activity, but it is limited by high costs and it is not readily available. Muscle ultrasound (MUS) has been recently proposed as a valuable tool for the diagnosis and activity assessment of muscle involvement in IIM patients.

Objectives:

To define the role of MUS in the diagnosis and assessment of disease activity in IIM through quantitative analysis of MUS

Methods:

This was a prospective study conducted from February 2019 to November 2019. 41 patients with IIM: 17 men and 24 women, median age 61.4 years, of which 20 were polymyositis (PM), 16 dermatomyositis (DM) and 5 inclusion body myositis (IBM) were included. 30 healthy subjects (HS), comparable in age and gender to patients, were recruited as controls. In every patient and control MUS of upper and lower extremities was performed (in total 10 muscles per side) and digital images were saved. Quantitative muscle echo intensity (QME) was calculated using an image processing program (ImageJ) to obtain the mean value of greyscale (mGS) for each muscle. For patients with IIM creatine phosphokinase (CPK) levels were recorded, duration of disease (in months) was calculated and clinical evaluation tools for the assessment of disease activity were performed, such as manual muscle testing (MMT8), patient and physician visual analogue scales (pVAS, phVAS), health assessment questionnaire (HAQ) and myositis disease activity assessment tool (MDAAT).

Results:

Patients had higher values of mGS across all muscles examined than controls (p<0.001). Among patients QME showed a negative correlation with MMT8 (p<0.001, -0.641<r<-0.412), but no correlation with CPK levels or duration of disease. A positive correlation was found between QME and HAQ (p<0.05; 0.320<r<0.599), pVAS (0.003<p<0.046; 0.314<r<0.455) and phVAS (0.029<p<0.002; 0.341<r<0.471). No significant correlation was found between QME and MDAAT and no statistically significant differences of muscle echo intensity were observed between patients with IBM, DM and PM.

Conclusion:

Quantitative analysis of MUS showed to be useful to differentiate IIM patients from healthy subjects, therefore it could be a helpful technique to screen patients with muscular symptoms in which perform additional investigations. In our study, the data collected did not allow to assess the disease activity of IIM patients and did not allow to distinguish between the 3 different subgroups of IIM patients, but further studies may help in the identification of different muscular patterns to guide the clinical suspect and the possible role of MUS in the follow-up of the patients.

Disclosure of Interests:

Alessandra Tripoli: None declared, Simone Barsotti: None declared, Andrea Delle Sedie Speakers bureau: MSD, Lilly, Novartis, Abbvie, Celgene, Giacomo Aringhieri: None declared, Saverio Vitali: None declared, Rossella Neri: None declared, Davide Caramella: None declared, Marta Mosca: None declared