Serum immunoglobulin levels are reported in 75 patients with jaundice: 32 with jaundice due to virus hepatitis and 43 with jaundice due to obstruction. The degrees and variations of serum immunoglobulins (Ig), (IgM, IgG and IgA) in virus hepatitis (IH and SH) with jaundice are compared with those found in obstructive jaundice. In 32 of the patients with jaundice from virus hepatitis, serum IgM (100%) and IgG (75%) were elevated above 2 Standard Deviations from the mean values. Neither IgM nor IgG levels were elevated above 2 Standard Deviations from the mean values in 33 of 43 patients (76.7%) with obstructive jaundice. In the other 10 patients, serum IgM (21%) and IgG (7%) were elevated above 2 Standard Devituions from the mean values. Case histories are presented of the five of nine patients, with obstructions and IgM elevations who had inflammatory reactions about the biliary tract
