An evaluation of the effectiveness of three immunoglobulin G (IgG) removal procedures for routine IgM serological testing.
Three procedures for the removal of immunoglobulin G (IgG) from human serum were evaluated for their effectiveness in eliminating false-positive results caused by rheumatoid factor and in removing IgG from serum to reduce competing-IgG interference in IgM enzyme-linked immunosorbent assay (ELISA) testing. The procedures investigated employed two anti-human IgG diluents and a recombinant protein G-filled tube. The anti-human IgG was more effective than the protein G method in eliminating false-positive results caused by rheumatoid factor and removed 5.4% more IgG from serum samples in the normal range (< 1,700 mg/dl) and up to 16.4% more of the IgG from samples with elevated levels (> 1,700 mg/dl). The recombinant protein G removed less IgM than the anti-human IgG diluents; however, this difference did not affect the results of the ELISA. For these reasons, the in-house-developed anti-human IgG diluent proved to be the most effective and economical for IgM serological testing.
Martins
T B
TB
Department of Immunology, Associated Regional and University Pathologists, Salt Lake City, UT 84108.
Jaskowski
T D
TD
Mouritsen
C L
CL
Hill
H R
HR
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology; D036022:Capsid Proteins; D002498:Centrifugation; D004797:Enzyme-Linked Immunosorbent Assay; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D005189:False Positive Reactions; D006041:Goats; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000302:isolation & purification*; D007075:Immunoglobulin M / Q000097:blood*; D007163:Immunosorbent Techniques; D009391:Nephelometry and Turbidimetry; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D015203:Reproducibility of Results; D012217:Rheumatoid Factor / Q000302:isolation & purification / Q000494:pharmacology; D013205:Staphylococcal Protein A
D000888:Antibodies, Anti-Idiotypic; D000936:Antigen-Antibody Complex; D000956:Antigens, Viral; D036022:Capsid Proteins; C041788:Epstein-Barr viral capsid antigen; C029152:G-substrate; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; D013205:Staphylococcal Protein A; D012217:Rheumatoid Factor