Data on 100 patients: 50 with Sjögren's disease (SD) and 50 with Sjögren's syndrome (SS) accompanied by systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic scleroderma (SSD) were analysed. It was characteristic of SD to have hyperproteinemia, hypergammaglobulinemia, high levels of the rheumatoid factor (RF), circulating immune complexes (CIC), and cryoglobulins, anti-Ro and anti-La; SD + RA was characterized by RF, hypercomplementemia; SS + SLE was characterized by various antibodies to nucleic acids (nDNA, DNP (and anti-Sm, antinuclear factor (ANF) of homogenous and peripheral types of glow, hypercomplementemia. The main systemic manifestations of SD (arthritis, vasculitis) and a high activity of the process was associated with the presence of anti-Ro/La, and marked local manifestations of the dry syndrome--with antibodies to nDNA and dDNA. And vice versa in SS + SLE anti-nDNA antibodies correlated with anemia, serositis, nephritis, vasculitis and the presence of anti-Ro/La--with a comparatively mild renal pathology. The presence of high titres of RF in SB correlated with the absence of the adequate therapy, the presence of hypergammaglobulinemic purpura, weakly pronounced local manifestations; but a decrease in the titres of RF and an increase in the titres of ANF; anti-nDNA, anti-DNP in young patients with SD proved to be a prognostically unfavourable factor. The presence of CIC was associated with hypergammaglobulinemic purpura and affection of the eyes, and hypocomplementemia--with affection of the kidneys, joints and salivary glands in patients with SD.