Prelimenary evaluation of β₂ microglobulin as determined by radioimmunoassay (RIA)

β₂ microglobulin（β₂ m）concentrations of 246 serum and 58 urine specimens in various diseases were measured by RIA.The results showed that:1.Serum β₂ m was superior in reflecting the GFR to the serum creatinine,being helpful in detecting minor impairment of renal glomerular function.2.Serum β₂ m was elevated to varying degrees in liver diseases and appears to be diagnostic aid in such conditions.3.Serum β₂ m was increased in most of malignant hematological diseases,more markedly in the active stage than in the remission stage of malignant lymphoma and acute lymphocytic leukemia,and might being,perhaps,useful in monitoring the courses of these diseases.Serum β₂ m did notshow significant difference examined at the pre or at the post-operatively stage in the patients with stomach cancers and whether it would be a marker for gastrointestinal cancer or not remains to be seen.4.Urinary β₂ m secretions were markedly increased in diabetic nephropathy,particularly higher in diabetics without protein uria than normal while decreased after insulin and/or oral hypoglycemic agents treatment.It was, therefore suggested that the renal tubular functions were also impaired in diabetics and can be reversed in part when metabolic status was put under control.