Relevance of urinary excretion of alcian blue-glycosaminoglycans complexes and hydroxyproline to disease activity in rheumatoid arthritis.

Urinary excretion of glycosaminoglycans (GAG) and hydroxyproline was studied in 42 adult patients with rheumatoid arthritis (RA). A significant increase of GAG and hydroxyproline was found in RA patients compared to normal controls. RA patients fulfilling the criteria of disease activity were found to have urinary excretion of GAG and hydroxyproline higher than of RA patients not fulfilling these criteria. No significant correlation however was observed between urinary GAG and hydroxyproline. GAG and hydroxyproline excretion might be the expression of cartilage destruction and bone involvement and both may be related to the activity of the rheumatoid process.

Plasma proteins in human cortical bone: enrichment of alpha 2 HS-glycoprotein, alpha 1 acid-glycoprotein, and IgE.

Human cortical bones were extracted with EDTA, and the residue after EDTA extraction was digested with bacterial collagenase. Ten plasma proteins were identified and quantitated in the EDTA extracts. Three of them--IgE, IgD, and alpha 1acid-glycoprotein--had not previously been described in bone or dentine. Five plasma proteins identified in collagenase digests are albumin, IgG, IgA, IgE, and alpha 1acid-glycoprotein. IgE, alpha 1acid-glycoprotein, and alpha 2HS-glycoprotein were found to be concentrated in the bone more than other plasma proteins by factors between 11 and 525. The identification of plasma proteins was facilitated by the addition of polyethylene glycol in agarose gel. The presence of plasma proteins both in EDTA extracts and in collagenase digests suggests their structural role in bone.