title: Serologic testing for reactive arthritis.
abstract: The objective of the study was to determine the sensitivity and specificity of quantitative serum antibody response to Salmonella enteritidis lipopolysaccharide (LPS) as a diagnostic test for post-Salmonella reactive arthritis (ReA). In a single food-source outbreak of Salmonella enteritidis, serum was collected from dysenteric individuals with and without ReA at 6, 12, and 24 months post infection. Serum was also collected from control patients with no prior exposure to Salmonella infection. Quantitative measurements of isotypic antibodies to Salmonella enteritidis LPS were performed by an ELISA. Sensitivity and specificity of quantitative isotypic antibody levels over time were plotted on receiver operator characteristic (ROC) curves. Serum IgG and IgA anti-LPS were found to be present in higher levels in the ReA patients than in controls. Using the optimal cutoff of 0.10 selected from an ROC curve, IgG anti-LPS is 88% sensitive and 94% specific, and IgA anti-LPS is 75% sensitive and 100% specific. We conclude that IgA anti-LPS is both sensitive and specific in distinguishing prior exposure to Salmonella LPS in ReA patients compared to unexposed controls.
authors.affiliation: St. Boniface Arthritis Research Unit, Medical Microbiology Department, St. Boniface General Hospital, Winnipeg, Manitoba.
authors.forename: G T
authors.initials: GT
authors.lastname: Thomson
authors.forename: M
authors.initials: M
authors.lastname: Alfa
authors.forename: K
authors.initials: K
authors.lastname: Orr
authors.forename: B R
authors.initials: BR
authors.lastname: Thomson
authors.forename: N
authors.initials: N
authors.lastname: Olson
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D016918:Arthritis, Reactive / Q000097:blood* / Q000175:diagnosis / Q000382:microbiology; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D010003:Osteoarthritis / Q000097:blood / Q000175:diagnosis; D000091402:Prohibitins; D012372:ROC Curve; D012478:Salmonella Food Poisoning / Q000097:blood* / Q000276:immunology; D012477:Salmonella enteritidis; D012680:Sensitivity and Specificity; D012698:Serologic Tests
chemical_list: D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; C000717331:PHB2 protein, human; D000091402:Prohibitins