ROLE OF PHAGOCYTOSIS IN ACUTE GOUTY ARTHRITIS
The mere presence of urate crystals in the joint cannot be correlated with the appearance of acute gouty arthritic symptoms. Individuals who have never had any gouty arthritic problems have nonetheless been found to have uric acid deposited on their articular cartilage. Acute attacks are generally the result of granulocytic phagocytosis of the urate crystals. This engulfing of the crystals is accompanied by cellular release of chemotac-tic lipids, lysosomal enzymes, and acidic substances into the synovial tissues. The lipids appear to trigger further phagocytosis, whereas the acidic compounds decrease local pH to the point that increased urate crystal for-mation is favored.
In addition to the phagocytic activity of the leuko-cytes, small peptide substances, such as the kinins, which are thought to be partially responsible for the local in-flammatory response in gouty arthritis, accumulate in the joint space. The inflammation is associated with lo-cal vasodilation, increased vascular permeability, and pain.