CLINICAL AND LABORATORY FEATURES OF ANTICENTROMERE ANTIBODY-POSITIVE SJö GREN’S SYNDROME

Objective : to study the clinical and laboratory features of patients with anticentromere antibody (ACA) positive Sjö gren’s syndrome (SjS); to assess the spectrum of autoantibodies in patients of this group; to determine the frequency with which the SjS patients who are highly positive for ACA, meet the international classification criteria for SjS and systemic sclerosis (SS); to reveal the incidence of MALT lymphomas in this patient group; to estimate the incidence of primary biliary cirrhosis (PBC)/biliary lesions as part of autoimmune epithelitis in SjS in this patient group. Material and methods . A total of 83 patients with ACA positive SjS were comprehensively examined at the V.A. Nasonova Research Institute of Rheumatology during the period 2012 to 2018. The inclusion criteria were con formity to the 2001 Russian SjS criteria and a high ACA level. MALT lymphomas were diagnosed on the basis of histological and immunohistochemical studies and polymerase chain reaction-based determination of B-cell clonality in the biopsy samples of affected organs according to the World Health Organization classification of Hematopoietic Tumors. The diagnosis of PBC/biliary lesions was made on the basis of histological and immunohistochemical studies of liver biopsy specimens. Results and discussion . The investigation revealed low detection rates for anti-Ro antibodies (32.5%), anti-La antibodies (7.2%) and rheumatoid factor (RF) (21.7%), which were typical for the classical SjS immunophenotype), increased ESR (14%), leukopenia (7%), hypergammaglobulinemia (17.6%), elevated levels of IgG (9.5%) and IgA (18.7%), and hypocomplementemia (16.1%) in the ACA positive SjS patients. Despite the low detection rate of RF, 15 (18%) patients in this group developed MALT lymphomas: 14 patients had salivary gland MALT lymphoma and one patient had tonsil MALT lymphoma with peripheral lymph node involvement (generalized marginal zone lymphoma). Also, the patients of this group showed high detection rates for AMA antibodies (34.6%), increased IgM level (29.7%) and a higher risk for PBC/biliary lesions as a manifestation of autoimmune epithelitis in SjS (14.5%). AMA-antibodies were absent in only two patients who were diagnosed with liver disease according to biopsy specimens. Nervous system and renal lesions, antiphospholipid syndrome, rheumatoid arthritis, hypergammaglobulinemic purpura, and cryoglobulinemic vasculitis were much less common and sporadic. Also ACA-positive SjS patie