Background Because immunity against Staphylococcus aureus has not been fully elucidated, there is no diagnostic test to gauge how robust a patient's host response is likely to be. Therefore, we aimed to develop a test for specific antibodies in serum with diagnostic and prognostic potential. Questions/Purposes We describe the development and validation of a multiplex immunoassay for characterizing a patient's immune response against 14 known S aureus antigens, which we then used to answer four questions: (1) Do certain antigens predominate in the immune response against S aureus? (2) Is there a predominant pattern of antigens recognized by patients and mice with infections? (3) Is the immunoglobulin G (IgG) response to any single antigen a useful predictor of ongoing S aureus infection? (4) Does measurement of the combined response against all 14 antigens provide a better predictor of ongoing infection? Methods A case-control study was performed. Sera were collected from 35 consecutive patients with S aureus culture-confirmed (methicillin-sensitive S aureus or methicillin-resistant S aureus) musculoskeletal infections The institution of one or more of the authors (EMS, SLK, JLD, CAB) has received, during the study period, funding from the National Institutes of Health, NIAMS (Bethesda, MD, USA) and (EMS, SLK, JLD) the AOTrauma Clinical Priority Program (Davos, Switzerland). One of the authors certifies that he (JLD) or she or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of USD 10,000 to 100,000 from Telephus Medical LLC (San Diego, CA, USA) and an amount of less than USD 10,000 from Calorics Pharmaceuticals (Waltham, MA, USA). One of the authors certifies that he (EMS) or she or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of USD 10,000 to 100,000 from Telephus Medical LLC (San Diego, CA, USA). One of the authors certifies that he (SLK) or she or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of less than USD 10,000 from Surgical Excellence Healthcare Quality Consulting, and an amount of USD 10,000 to 100,000 from Sage Publications (Thousand Oaks, CA, USA) One of the authors certifies that he (CAB) or she or a member of his or her immediate family, has received or may receive payments or benefits, during the study period, an amount of USD 10,000 to 100,000 from the FDA (Silver Spring, MD, USA), and an amount of USD 10,000 to 100,000 from Boston Scientific (Marlborough, MA, USA), an amount of USD 10,000 to 100,000 from Lundbeck Inc (Deerfield, IL, USA), an amount of USD 10,000 to 100,000 from Patient-Centered Outcomes Research Institute (PCORI, Washington, DC, USA), and an amount of less than USD 10,000 from Auspex Pharmaceuticals (La Jolla, CA, USA). All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board mem...
