title: Enhancement of cryoprecipitation from hypotonic serum: a comparative study in normals and in patients with connective tissue diseases.
abstract: In a study of 17 normals and 26 patients we have established a normal range for cryoglobulins in a standard and a simple hypotonic system. In a comparison of standard and hypotonic cryoprecipitates in patients with connective tissue diseases we showed a significant increase in protein content (p less than 0.001), IgM (p less than 0.01) and IgM rheumatoid factor (p less than 0.01) in the hypotonic samples. The ratios of IgM RF/IgM in hypotonic cryoglobulins compared to standard cryoglobulins were significantly increased as shown by a chi 2 analysis in both normals (p less than 0.05) and patients (p less than 0.01). Estimation of cryoglobulins in a hypotonic system is a useful simple test which may detect distinct groups of proteins and rheumatoid factors. Precipitates were demonstrated in patients who had previously been considered serologically normal.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003240:Connective Tissue Diseases / Q000276:immunology*; D003450:Cryoglobulins / Q000032:analysis*; D006801:Humans; D007038:Hypotonic Solutions; D007075:Immunoglobulin M / Q000032:analysis; D008875:Middle Aged; D011233:Precipitin Tests / Q000379:methods; D011863:Radioimmunoassay; D012217:Rheumatoid Factor / Q000032:analysis
chemical_list: D003450:Cryoglobulins; D007038:Hypotonic Solutions; D007075:Immunoglobulin M; D012217:Rheumatoid Factor