Heterophilic antibody interference in commercial immunoassays; a screening study using paired native and pre-blocked sera

Abstract

Background: Heterophilic antibodies are still an important source of interference in immunoassays. We have conducted a screening study for interference in a panel of commercially available assays using two sera known to contain high titer Fc-reactive heterophilic antibodies. Methods: The sera were distributed to laboratories participating in the Nordic External Quality Assessment cooperation (EQANord). Duplicate samples pre-blocked with aggregated murine monoclonal MAK33 were also supplied. Discrepancies ()50%) between the results for native and blocked samples were used to classify the tested assays as susceptible to interference. A total of 170 different assay kits covering 91 analytes were tested. Results: We found that 21 assays, covering 19 different analytes, were susceptible to interference from the heterophilic antibodies in the two sera. Many of these are clinically and commercially important assays. Some of the false results were grossly elevated and could have been detrimental to patient care in a clinical setting. Conclusions: Heterophilic antibodies with Fc-reactivity remain a threat. A more widespread use of antibody fragments and aggregated immunoglobulin could potentially improve the heterophilic antibody resistance of assays intended for clinical use.

Cytokines as Biomarkers in Rheumatoid Arthritis

“…RF is an autoantibody directed against the Fc portion of IgG and is found in 75% of patients presenting with RA as well as other diseases such as Sjögren's syndrome, infective endocarditis, systemic sclerosis, and systemic lupus erythematous (SLE) [24]. RF was shown to exhibit most of the heterophilic antibody properties with several antigen cross-reactions [25] and hence immunoassay in RA is particularly sensitive to this issue and needs careful evaluation for RF interference [12, 150–153]. Heterophilic immunoglobulin may further develop as a result of treatment with drugs attached to mouse (or humanised) monoclonal antibodies.…”

Reversible adrenal insufficiency and heterophile antibodies in a case of autoimmune polyendocrinopathy syndrome

“…After thyroxin replacement he became clinically euthyroid but his hormonal profile showed elevated TSH levels. Discordantly elevated TSH can be due to heterophillic antibodies,[3] anti-TSH antibodies[4] or macro-TSH. [5] Heterophile antibodies are antibodies induced by external antigens (heterophile antigens) that cross-react with self-antigens.…”

“…He had discordantly elevated thyrotropin (TSH) with normal T3 and T4 levels and clinical euthyroidism on adequate thyroxin replacement. Spuriously high TSH in assay can be due to heterophillic antibodies,[3] anti-TSH antibodies[4] or macro-TSH. [5] In our case discordant result were found to be due to heterophile antibody.…”

How many biomarkers to discriminate neurodegenerative dementia?

“…Indeed, it is worth noting that the variability of the results is very high among the many studies on oligomeric aggregates in CSF. Actually, in the majority of these studies, Ab and aSyn oligomers have been measured using immunometric or cytofluorimetric assay, which can give false positive results 152,159 due to the presence of interfering factors, such as heterophilic antibodies 160 , or the presence of RIPA buffer 151,153 . Therefore, the search for CSF oligomers may be very promising for the diagnosis and the comprehension of pathological pathways of neurodegenerative diseases, but a great effort is required to validate a reliable method of analysis.…”