Diagnostic potential of rapid electron microscopic analysis of joint effusions

Update on identification of pathogenic crystals in joint fluid

Crystal identification in joint fluid has been an essential part of diagnosis of joint disease. Recent advances have included progress in crystal identification on stained slides, attention to aspiration techniques, and arthrocenteses of asymptomatic joints. Challenges remain to increase use and optimize techniques.

Arthritis associated with crystals containing calcium

Varying combinations of acute inflammatory and/or chronic degenerative arthritis have been found to be associated with crystals of calcium pyrophosphate dihydrate (CPPD) and/or basic calcium phosphates (BCPs). Since the arthropathies associated with CPPDs and/or BCPs occur in older individuals, while diagnosis and treatment for monosodium urate monohydrate crystal deposition disease (gout) have become extremely precise and effective, joint problems associated with calcium crystals have become more common than those associated with monosodium urate monohydrate crystals. The classification, pathogenesis, clinical manifestations, and treatment of CPPD and BCP crystal deposition are discussed.

Canine platelet factors stimulate glycosaminoglycan synthesis by synovial cell and organ cultures

Glycosaminoglycan (GAG) synthesis in both canine synovial cell and organ cultures was stimulated by the addition of canine platelet extracts. Canine platelet factor (CPF) biologic activity obtained from acidic ethanol platelet extracts was partially purified, and resembled CTAP-III, a characterized human platelet protein known to stimulate human synovial cell GAG synthesis. These results identify a canine platelet CTAP factor activity, and indicate that the synoviocytes of organ-cultured synovial villi can respond to platelet factors which are potential mediators of synovial GAG synthesis.

The acutely swollen joint. First impressions may mislead

An acutely swollen joint may be indicative of a number of disease entities. A thorough history and physical examination are the cornerstones of evaluation. Laboratory findings can be useful in diagnosis, as can response to therapy (eg, response to penicillin in gonococcal arthritis is often the only criterion for diagnosis, as the organism is difficult to culture). Patients with malignancy (especially leukemia) or who are immunosuppressed or otherwise debilitated are at particular risk for a septic cause of swelling. Infectious arthritis should be the first potential cause looked for in these patients as well as in patients with such preexisting joint diseases as rheumatoid arthritis. The diagnosis of joint sepsis is confirmed by examination of aspirated joint fluid. In no case should a swollen joint be injected with corticosteroids until all possibility of infection has been eliminated.