[Quantification of macrophages and granulocytes at the joint cartilage-pannus junction in rheumatoid arthritis]

Rheumatoid-Arthritis (RA) is a systemic disease with chronic joint inflammation caused by complex immune mechanisms. Aim of our study was the analysis of the distributions of macrophages and neutrophils at the cartilage-pannus junction in order to assess the possible functional relationship of both cell types in cartilage damage. We used 39 samples of synovectomies from patients suffering from RA. The samples were stained by histological (Hematoxilin-Eosin, HE), enzymehistological (Naphtol-ASD) and immunohistochemical (Peroxidase-antiperoxidase, alkaline phosphatase-antialkaline phosphatase) techniques and examined by light microscopy. Lysozyme alpha-1-antitrypsin and alpha-1-antichymotrypsin were stained with peroxidase-antiperoxidase-technique, the monoclonal antibody for macrophages CD 68 were used in alkaline phosphatase-antialkaline phosphatase technique. We found a clear domination of macrophages at the cartilage-pannus junction compared to the number of neutrophils. Over 90% of the analyzed cells were identified as macrophages, which were presumably activated macrophages. The macrophages accumulated directly underneath the erosion front and infiltrated the cartilage. The cartilage showed erosions with clear infiltrations by macrophages. We conclude that this distribution is a clear sign of active cartilage destruction by macrophages and emphasize their role in perpetuation of the rheumatoid inflammation.