Radioimmunoassay of interleukin-6 in plasma.
We present a double-antibody radioimmunoassay for determining human interleukin-6 (IL-6) in biological fluids. The detection limit of the assay is 20 ng/L (B0 - 2 SD). Bound radioactivity in the range of 30% to 90% of the B0 counts corresponds to IL-6 concentrations of 100 to 14,000 ng/L. Analytical recovery of IL-6 added to EDTA-treated plasma averaged 25% more than that added to serum. The plasma concentration of IL-6 was therefore approximately 85 ng/L more than the concentration in simultaneously drawn serum. The mean serum concentration of IL-6 in 45 healthy subjects was 83 ng/L (range 20-290 ng/L), in 20 patients with multiple myeloma 303 ng/L, in 20 patients with rheumatoid arthritis 234 ng/L, and in 13 patients with systemic lupus erythematosus 183 ng/L. Markedly increased (greater than 3000 ng/L) concentrations of IL-6 were found in sera of patients with meningococcus meningitis and infectious peritonitis.
IV Department of Medicine, Helsinki University Central Hospital, Finland.
A M
AM
Teppo
K
K
Metsärinne
F
F
Fyhrquist
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D015850:Interleukin-6 / Q000097:blood*; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000097:blood; D010538:Peritonitis / Q000097:blood; D011863:Radioimmunoassay; D012016:Reference Values
D015850:Interleukin-6; D007457:Iodine Radioisotopes