GELATINASE-B IN CHRONIC SYNOVITIS - IMMUNOLOCALIZATION WITH A MONOCLONAL-ANTIBODY

Gelatinase B is a matrix metalloproteinase (MMP-9) involved in the rem odelling of extracellular matrices of connective tissues. With the use of specific monoclonal antibodies against human gelatinase B, the pro ducer cell types were pinpointed in histopathological sections of a nu mber of arthritic diseases. In cases of acute joint trauma, chondromat osis, villonodular synovitis and a cyst of a bursa, high numbers of st rongly immunopositive neutrophils were observed in additon to weaker s taining macrophages. Activated macrophages with giant cell morphology clearly stained with the gelatinase B-specific monoclonal antibody in the case of villonodular synovitis and in an epidermoid cyst. However, in the sections from patients with rheumatoid arthritis, no immunosta ining was seen. Tn other cases of chronic synovitis, however, within t he lymphocyte nodular aggregates a strong gelatinase B expression tvas observed in morphologically identified dendritic cells. In conclusion , gelatinase B production in joint disease seems to be predominantly b y neutrophils and cell types of the macrophage/antigen-presenting cell lineage.