Degradation of human normal immunoglobulin preparations and the level of measles virus antibodies.
Seventy-four batches of normal human immunoglobulin of placental origin (NHIp) and 25 batches of the preparation derived from the serum (NHIs) were tested. The batches were divided into groups (A-E) according to production date and presence of sediment. The degree of degradation of NHI preparations was determined measuring the components soluble in trichloroacetic acid (TCASC), performing molecular filtration or carrying out electrophoresis in polyacrylamide gel. The level of antibodies to measles virus was determined with the enzymatic immunoadsorption test (ELISA) and haemagglutination inhibition test (HIT). It was found that NHI preparations were undergoing significant degradation before their expiration date. The content of TCASC ranged from 1.83% for NHIs preparations recently produced (group E) to 10.57-10.63% respectively in NHIp preparations with sediment (groups B and A). Molecular filtration made possible isolation of a polymer, a monomer, and degradation products. The level of antibodies against measles virus was the lower (7,400) the greater was the degree of degradation of NHIp preparations in the relation of NHI preparations recently produced (21,500).