AB0572 USEFULNESS OF MINOR SALIVARY GLAND BIOPSY IN THE DIAGNOSIS OF PATIENTS WITH SUSPECTED PRIMARY SJÖGREN’S SYNDROME

Abstract

BackgroundThe classification system for Sjögren’s syndrome (SS) proposed by the American-European Consensus Group (AECG) and the revised diagrams proposed by the American College of Rheumatology (ACR) include an altered minor salivary gland biopsy (MSGB) or positive antiRo, among other findings. Thus, an altered MSGB is a particularly important finding in patients with autoantibody-negative. A retrospective cohort study showed that a positive biopsy result led to a definitive diagnosis in 80% of patients1.ObjectivesTo assess the usefulness of MSGB in the diagnosis of SS in anti-SSA/SSB (Ro/La) negative patients.MethodsRetrospective descriptive study in patients with suspected SS in which MSGB were collected according to standard clinical practice over a consecutive period (from September 2020 to May 2021) in the Rheumatology Department of a tertiary hospital.Patients were grouped according to the reason for requesting the biopsy: 1) Dry eye/oral syndrome (DEOS), 2) DEOS + altered Saxon/Schirmer, 3) DEOS + positive antinuclear antibodies (ANA+), 4) DEOS + (ANA+) + other serological alterations (hypergammaglobulinaemia, rheumatoid factor (RF), hypocomplementemia), 5) DEOS + extraglandular manifestations (EG) + (ANA+) +/- other serological alterations. The following variables were collected: age, sex, dry eye/oral syndrome, Raynaud’s phenomenon, EG manifestations (arthritis, autoimmune hepatitis, primary biliary cirrhosis, interstitial lung disease, pleuropericarditis, autoimmune chronic nephropathy suspected or tubulointerstitial nephritis and/or neurological manifestations), ANA, hypergammaglobulinaemia, RF, hypocomplementemia, Saxon and Schirmer tests and histological result of MSGB according to its Focus Score (FS); MSGB was considered altered when FS was ≥1. Descriptive analysis was performed (means and frequencies); Chi-square test was used to compare the reasons for requesting MSGB between patients with altered and unaltered results and to compare whether any of the groups (Groups 2-5) were more frequently associated with an altered MSGB compared to patients presenting only with dry syndrome (Group 1).ResultsSeventy-eight MSGB were collected. Mean age of patients was 55 years; 90% were women. ANA were present in 17% of patients with altered MSGB. DEOS was the suspected manifestation in 83% of patients, 13% had Raynaud’s phenomenon and 47% had some EG manifestation. MSGB was compatible with a diagnosis of SS (according to 2002/2016 classification criteria) in 28% of anti-SSA/SSB negative patients. Patients with dry syndrome and positive ANA (Group 3) were significantly associated with MSGB altered (Table 1).Table 1. Comparative table of patterns inidicated in the reasons for requesting a MSGB. *Not significant (NS).Reason for request (%)MSGB alteredMSGB unalteredpp vs drynessDEOS (50)19460.65DEOS + Saxon/Schirmer (38)15340.47NSDEOS + ANA (30)11270.67NSDEOS + ANA + others (8)640.410.05DEOS + EG + ANA (14)9150.69NSConclusionMSGB was compatible with a diagnosis of SS in 28% of anti-SSA/SSB negative patients. The data suggest that patients presenting with objectified dryness with Saxon and/or Schirmer test, as well as those with extraglandular manifestations and ANA+ and/or other serological alterations, are more likely to have a compatible with SS result on MSGB. Studies with larger numbers of patients are needed.