PT  - JOURNAL ARTICLE
AU  - O H Meurman
AU  - B R Ziola
TI  - IgM-class rheumatoid factor interference in the solid-phase radioimmunoassay of rubella-specific IgM antibodies.
AID  - 10.1136/jcp.31.5.483
DP  - 1978 May 01
TA  - Journal of Clinical Pathology
PG  - 483--487
VI  - 31
IP  - 5
4099  - http://jcp.bmj.com/content/31/5/483.short
4100  - http://jcp.bmj.com/content/31/5/483.full
SO  - J Clin Pathol1978 May 01; 31
AB  - The interference of IgM-class rheumatoid factor (RF) in the solid-phase radioimmunoassay (RIA) of rubella virus IgM antibodies was studied. Acute rubella infections did not significantly activate RF. False-positive rubella antibody results were obtained, however, when patients with raised RF levels were tested. If a low rubella IgG antibody titre was present, a high level of RF was required to cause a false-positive IgM result; conversely, in sera with high IgG titres, only a low level of RF was required for interference. Although the false-positive IgM titres obtained were generally low, thet did show a positive correlation to both RF levels and rubella IgG titres. False-positive results were successfully avoided by removing the RF by absorption with heat-aggregated human gamma globulin. The absorption procedure did not affect true rubella IgM antibody titres.