Explanations on the request form of the Clinical Department of Rheumatology and Immunology

Plasma proteins:

  • Immunoglobulins: useful in cases of autoimmune diseases, hypogammaglobulinemia, gammopathies, immunodeficiencies, chronic inflammation
  • CRP highly sensitive: elevated in all inflammatory processes, e.g. acute rheumatoid arthritis, bacterial infections, barely or moderately elevated in SLE, viral infections and tumors, prognostic factor in coronary heart disease
  • ß2-microglobulin: useful in lymphomas, plasmocytomas, tubulointerstitial kidney damage, dialysis patients
  • IgG subclasses: For upper and lower respiratory tract infections, susceptibility to infections, chronic intestinal diseases, autoimmune diseases


Complement analysis:

  • Total complement (CH50): Screening test for the diagnosis of conditions with hypocomplementary activity. Determination only possible in fresh serum (max. 4h); useful in combination with the determination of C3 and C4
  • AP50: Screening test for the alternative complement pathway
  • C3 and C4: The reduction of C3 and C4 indicates complement activation. Decreased in active SLE, membranoproliferative GN, cryoglobulinemia
  • C1 inhibitor concentration and activity: Regulator of the classic complement cascade, inhibitor of C1r and C1s. Decrease in angioneurotic edema, CLL, malignant lymphomas, liver cirrhosis, pneumonia and other infections. Always send in citrated plasma to determine activity!


Streptococcus and staphylococcus antibodies:

  • Anti-streptolysin-O: Detection of a previous infection with group A streptococcus (GAS) e.g. rheumatic fever, scarlet fever, tonsilitis, GN, myositis, pneumonia
  • Anti-streptococcal denase B: The antibody response starts later and is stronger than that against streptolysin-O
  • Antistaphylolysin: increase in antibodies after approx. 3 weeks in the case of infection with S. Aureus


Rheumatoid factors:

  • RF: In rheumatic and other diseases such as rheumatoid arthritis, SLE, Sjögren's syndrome, MCTD, hepatitis, cryoglobulinemia
  • CCP: CCP antibodies are a very specific marker of rheumatoid arthritis and have a high predictive value for the transition from undifferentiated to rheumatoid arthritis


Paraproteins:

  • Immunofixation: For the diagnosis and classification of gammopathies
  • Bence-Jones protein (urine): Submission of 20 ml of a 24-hour urine collection. For the detection of free immunoglobulin light chains excreted in the urine


Collagenosis markers:

  • Antinuclear antibodies (ANA): Indirect immunofluorescence test with polyvalent FITC-labeled antisera. If the result is positive >= 1:160, the anti-DNA and anti-ENA antibodies are automatically determined. High titres especially in collagenoses such as SLE and Sjögren's syndrome, also in rheumatoid arthritis, autoimmune hepatitis
  • Anti-DNA antibodies: detection of AK against dsDNA in SLE using various analysis methods: RIA, Elisa, Crithidia (ind. fluorescence)
  • Anti-ENA antibodies: antibodies against extractable nuclear antigens AK against Sm in SLE; U1-snRNP in mixed collagenoses and SLE, Sharp syndrome; SS-A (Ro) and SS-B (La) in Sjögren's syndrome, SLE; Scl-70 and CENP in scleroderma and CREST syndrome; Jo-1 in poly- and dermatomyositis
  • AK against alpha-fodrin: screening marker for Sjögren's syndrome (prevalence 93%), correlates with inflammatory activity
  • Anti-cardiolipin antibodies: In antiphospholipid syndrome, SLE and related autoimmune diseases, thromboses, coagulation disorders


Vasculitis markers:

  • Anticytoplasmic antibodies (ANCA): Marker for vasculitis diagnostics (Wegener's granulomatosis and microscopic polyangiitis) and chronic inflammatory diseases
  • Cryoglobulins: For rheumatic and infectious diseases, liver inflammation, autoimmune diseases. In the case of positive findings and sufficient precipitate, immunofixation is performed to classify cryoglobulinemia
  • Cryocrit: Quantitative determination of cryoglobulins


Further specific AK markers:

  • PM-Scl, Mi-2 : PM-Scl: in patients with an overlap of scleroderma and myositis, overall in approx. 5 % of scleroderma patients. Mi-2: in 10 % of patients with autoimmune myositis, especially dermatomyositis
  • Rib-P: specific marker of SLE, activity-dependent in up to 30 % of SLE patients
  • RNA polymerase III: specific marker of scleroderma, in approx. 15 % of patients, associated with renal crisis
  • Fibrillarin: high-titer antibodies are associated with scleroderma
  • Myositis panel: (Jo-1, SRP, Ku, PL7, PL12, PmScl100): specific markers of autoimmune myositis
  • GBM: specific marker of anti-GBM disease (Goodpasture syndrome), with glomerulonephritis and alveolitis


Organ antibodies:

  • Anti-mitochondrial antibodies (AMA): In primary biliary cirrhosis, hepatitis, partly in SLE, Sjögren's syndrome, rheum. Arthritis
  • AK against gastric parietal cells: Chronic gastritis, pernicious anemia and autoimmune thyroid diseases
  • AK against smooth muscle: In autoimmune hepatitis and other chronic liver diseases
  • AK against striated muscle: In myasthenia gravis, thymoma, thymus dysplasia, polymyositis
  • AK against heart muscle: In post-myocardial infarction syndrome, post-myocardiotomy syndrome, endocarditis lenta, myocarditis, cardiomyopathies
  • AK against parotid gland: In Sjögren's syndrome, parotid gland tumors
  • AK against adrenal gland: for adison's disease