1st order laboratory parameters – obligatory laboratory tests.
- Complete blood count [anemia (anemia); leukopenia (decreased white blood cell count); thrombocytopenia (< 100,000/μl/decreased platelet count)]
- Inflammatory parameters – CRP (C-reactive protein) [usually unremarkable] and ESR (erythrocyte sedimentation rate) [↑]
- Gamma globulins (antibodies) [polyclonal hypergammaglobulinemia]
- Detection of autoantibodies (IgG) vs.
- Antigens in the cytoplasm of the salivary duct epithelium (biopsy material) (SS-A and SS-B (specific antibodies of ANA)) and
- Autoantibodies against α-fodrin [SS-A (anti-Ro/SSA antibody. Abbreviation: SS-A (Ro)/SSA(Ro) antibodies) pos: 40-80%; SS-B pos: 40-80%; ANA pos: 70% of cases].
- Mucosal biopsy (tissue sample) – from the inside of the lip or an enlarged salivary gland [lymphocyte infiltration (enforcement of the mucosa or salivary glands with lymphocytes/belong to the white blood cells) → is considered a crucial diagnostic criterion]
- Rheumatoid diagnostics – rheumatoid factor (RF), CCP-AK (cyclic citrulline peptide antibodies), ANA (antinuclear antibodies).
- Rheumatoid factors are detectable in approximately 50% of affected individuals without suffering from rheumatoid arthritis.
Since approximately 5% of patients with Sjögren’s syndrome develop non-Hodgkin’s syndrome in the course, regular laboratory tests are required. In this context, attention must be paid to the occurrence of monoclonal hypergammaglobulinemia.
