Antibodies to Newcastle disease virus in various human diseases.

Sera of patients with infectious mononucleosis (IM) and various other diseases were studied for agglutinins against Newcastle disease virus (NDV)-modified human group O red blood cells (NDVO) and antibodies to the NDV preparations. In agreement with previous studies, the NDVO antibodies are found in a wide variety of diseases in addition to IM, including Japanese IM-like syndrome (22%), syphilis (24%), lepromatous leprosy (30%), systemic lupus erythematosus (29%), multiple sclerosis (18%) and cancer (17%); these antibodies were also found in patients with renal allografts (29%). It was also noted that the Victoria (VIC), Roakin and Herts strains, but not B1 strain of NDV are active in the NDVO agglutination, and VIC and Roakin strains, but not B1 strain in the immunodiffusion. Immunodiffusion and enzyme immunoassay with various preparations of the VIC strain revealed that the major antigen(s) of the virus under study is carried by the hemagglutinin-neuraminidase (H-N) glycoproteins. The H-N molecule was also shown to be able to modify human erythrocytes for the agglutination by the pathologic sera.