Synovial fluid lipids in normal individuals and patients with rheumatoid arthritis

Abstract

Normal human synovial fluid contains trace amounts of phospholipids and cholesterol. Phospholipid composition is similar to that in serum. Rheumatoid synovial fluid contains increased amounts of phospholipid, cholesterol, and neutral lipids. I n most cases the concentration is 40 to 60 per cent of that found in simultaneously collected serum specimens. A direct relationship appears to exist between total synovial fluid protein and lipid concentration. No relationship could be established between lipid content in rheumatoid synovial fluid, and totaI cell content, hyaluronic acid, severity or duration of synovitis in the involved joint.Normal liquido synovial in humanos contine quantitates tracia de phospholipidos e de cholesterol. Iste phospholipidos es simile in composition a illos del sero. Le liquido synovial ab patientes rheumatoide contine augmentate quantitates de phospholipido, de cholesterol, e de lipidos neutre. In le majoritate del casos, le concentration es 40 a 60 pro cento de ill0 trovate in simultaneemente colligite specimens de sero. Un relation directe pare exister inter le proteina total e le concentration lipidic in le liquido synovial. Nulle relation poteva esser establite inter le contento de lipidos in liquido synovial ab patientes rheumatoide e le parametros del total contento cellular, de acido hyaluronic, e del severitate o del duration de synovitis in le afficite articulation.NTEREST in further studies on the lipids of rheumatoid synovial fluid I was prompted by increasing evidence that a variety of cells synthesize both neutral lipids and phospholipids. Of considerable importance is the suggestion that several types of cells can contribute to extracellular lipid concentration. Recent investigations by Buchanan,l and Marks2 have shown that leukocytes possess this capacity. Preliminary reports by Jackson3 indicate the cells of the carrageenin granuloma synthesize lipids, and studies in this laboratory4 indicate that the cells of the polyvinyl granuloma will incorporate glycerol-C14 into phospholipids and neutral lipids. By comparing the lipid composition of serum with that of the cells, and the cell poor fraction of synovial fluid, it was hoped that additional information as to the source of these lipids might be obtained.Over a century ago Frerichs5 reported that traces of fat were present in bovine synovial fluid. Ropes and Bauers found no lipid in bovine fluid, but did report the presence of cholesterol in rheumatoid joint fluid. It was their impressicn that synovial lipids accumulated in joints where excessive tissue destruction had occurred. This observation was in agreement with earlier work by

A comparative evaluation of the metabolic profiles of normal and inflammatory knee‐joint synovial fluids by high resolution proton NMR spectroscopy

“…1.5-3.1 mM [6] which are approximately 2-fold greater than those of healthy human serum samples. However, in 'H Hahn spin-echo spectra of RA SF (Fig.…”

Lipoproteins containing apoprotein B are a major regulator of neutrophil responses to monosodium urate crystals.

“…It has been suggested that LDL is a major plasma regulator of HeLa cell adhesion to glass (62), which is a negatively charged surface like monosodium urate crystals. In addition, there is evidence that human serum enhances the stimulation by urate crystals ofnonmitogenic synovial fibroblast responses in vitro (63,64 (19,(55)(56)(57)(58), LDL may well represent an important factor in modulation of gouty inflammation.…”

Effect of extracellular fatty acids on lipid metabolism in cultured rabbit articular chondrocytes

“…This work indicates that the supply of lipids to cartilage, through the synovial fluid, is responsive to the dietary supply. Lipid content of synovial fluid has been shown to be low and to differ qualitatively from that of blood (5). Articular chondrocytes can synthesize oleic acid from carbohydrate sources, but linoleic and, indirectly arachidonic acids in the cells must be supplied primarily from synovial fluid.…”