[Laboratory diagnostics in rheumatology]

Peripheral blood cytology and acute phase reactants are used to distinguish between non-inflammatory and inflammatory rheumatic diseases, whereas chronic phase reactants and immunoglobulins can give guidance in distinguishing acute from chronic inflammatory conditions. The complicated path to a well-defined diagnosis of rheumatic disease involves autoimmune serology. This review puts special emphasis on the rational use of autoantibody results for diagnosis, prognosis, planning of follow-up, and estimating the need for therapy. A clinically important use of serodiagnostics can only be implemented by a close collaboration between clinicians and laboratory specialists. A tentative diagnosis is the best basis for ordering and interpreting laboratory results.