Comparison of immune assays for the detection of anti-HSP70 antibodies in patients with idiopathic sensorineural hearing loss.
BACKGROUND
Detection of anti-heat-shock protein 70 (HSP70) IgG response by Western blot (WB) is of clinical utility in a subset of patients with idiopathic sensorineural hearing loss (SNHL) due to autoimmunity.


METHODS
To validate an immune assay for the detection of anti-HSP70 antibody responses in the clinical laboratory, we employed a commercial anti-human HSP70 IgG/A/M ELISA and developed an anti-HSP70 IgG WB test. Using sera from 81 patients with idiopathic SNHL and 100 healthy controls, we assessed each assay performance with results from another diagnostic laboratory that utilizes a WB test.


RESULTS
Our results showed a significant lack of agreement between either WB assay and the anti-human HSP70 IgG/A/M ELISA for antibody-positive samples. Comparison of WB assays revealed a significant level of agreement (89.7%) for all samples tested.


CONCLUSIONS
Our data suggest that the antigenic targets in WB and ELISA immunoassays differ and demonstrate that the anti-HSP70 IgG WB test is reproducible within and between clinical laboratories. Thus, in the absence of disease-specific markers, the anti-HSP70 IgG WB assay could be of use to detect patients with idiopathic SNHL who might benefit from steroid treatment.
Tebo
Anne E
AE
Associated Regional and University Pathologists (ARUP) Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, United States. anne.tebo@aruplab.com
Jaskowski
Troy D
TD
Keith
Lindsay L
LL
Litwin
Christine M
CM
Hill
Harry R
HR
D000328:Adult; D000906:Antibodies / Q000032:analysis*; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology*; D006319:Hearing Loss, Sensorineural / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007118:Immunoassay; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis
D000906:Antibodies; D018840:HSP70 Heat-Shock Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M