B. Bucki et al., RICE BODIES CONTAINING CALCIUM MICROCRYST ALS IN OSTEOARTHRITIC SYNOVIAL-FLUIDS - A REPORT OF 4 CASES STUDIED BY TRANSMISSION ELECTRON-MICROSCOPY, Revue du rhumatisme, 61(6), 1994, pp. 415-420
Rice bodies are often found in inflammatory joint fluid specimens, esp
ecially from rheumatoid arthritis patients, but have rarely been repor
ted in osteoarthritis. We found rice bodies in knee joint fluid specim
ens from four of 88 patients with osteoarthritis. There were three mal
es and one female. Age ranged from 61 to 86 years. Three patients had
slowly progressive knee osteoarthritis and one had rapidly destructive
disease. Abundant, recurrent effusions occurred in all four patients
despite one to five local corticosteroid injections per patient and ra
diation synovectomy in two patients. The joint fluid specimens contain
ed 120 to 320 cellS/mm3 and large numbers of rice bodies that stained
with alizarin red S. Transmission electron microscopy studies showed t
hat the rice bodies were composed of fibrin and contained numerous int
ra- and extra-cellular calcium crystals composed of apatite alone in t
wo cases and of a combination of apatite and calcium pyrophosphate dih
ydrate in the two others. Collagen fibers and fragments of bone and ca
rtilage were present in a few rice bodies. Phagocytic cells, type C sy
noviocytes, chrondrocytes and a few inflammatory cells were also seen.
These rice bodies composed mainly of fibrin and apatite may have play
ed a role in the pathogenesis of the recurrent joint effusions in our
patients.