Proteins in fluid from non-keratinizing jaw cysts

Abstract. Contents of IgG, IgA and IgM in the fluids from 45 non-keratinizing jaw cysts, and of albumin, α₁-acid glycoprotein (orosomucoid), α₁-antitrypsin, α₂-macroglobulin, ceruloplasmin, C3 (C3/C3c-globulin), and transferrin in 15 of these cyst fluids have been determined by single radial immunodiffusion. In addition, cystic "fibrinogen" was measured in 37 cyst fluids. The mean ratios of IgG:IgA:IgM were for cyst fluid 20.1:4.8:1 and for the autologous serum 14.6:2.5:1. On the average, cyst fluid contained IgG, IgA and IgM in concentrations 1.2, 1.7 and 0.9 times, respectively, that of autologous serum. These ratios as well as data obtained from other calculations indicate partly local synthesis of cyst fluid immunoglobulins, mainly IgA and IgG. Remarkably high IgA levels were found in some cyst fluids. In apical periodontal cyst fluid there was a highly statistically significant positive correlation ( P <0.001) between the concentrations of IgG and IgA. No statistically significant differences were found between the Ig quantities in fluid from apical periodontal, follicular and residual cysts. The non-immunoglobulin proteins other than fibrinogen, which is structurally altered when present in cyst fluid, occurred in lower concentrations than in autologous serum. Cyst fluid to autologous serum concentration ratios (C_CF/C_S ratios) for the different proteins have been calculated. Considerably higher C_CF/C_S ratios were found for immunoglobulins than for non-immunoglobulin proteins with similar molecular weights. The implications of the findings for cyst wall permeability and clearance of proteins in cyst fluid arc discussed.