800. Misdiagnosis of Late Lyme Arthritis by Synovial Fluid Borrelia burgdorferi Western Blot Testing
Session: Abstracts: Oral Abstract Session: Bacterial Clinical Studies I
Friday, October 22, 2010: 3:30 PM
Background: Arthritis due to late Lyme disease is typically diagnosed by characteristic epidemiologic risk factors and history, presence of joint effusion and positive Borrelia burgdorferi serum IgG antibody results. Despite these diagnostic criteria, some commercial laboratories offer B. burgdorferi Western blot testing using synovial fluid specimens. The reliability, validity and utility of using this specimen type have not been studied

Methods: Demographic, diagnostic, treatment and outcomes data were analyzed from a retrospective case series of 11 patients who were referred to the infectious diseases clinic of a tertiary academic medical center with a diagnosis of Lyme disease based upon a previously obtained synovial fluid B. burgdorferi Western blot test.

Results: Ten of eleven (91%) patients who had been diagnosed with late Lyme arthritis based upon synovial fluid B. burgdorferi Western blot testing had negative serological tests for Lyme disease by standardized two-tier testing and did not satisfy published diagnostic criteria for Lyme arthritis. These patients had received an average of 79d of antibiotic therapy including 5/11 (45%) patients who received an average of 38d of parenteral ceftriaxone. None of these patients had a clinical response to antibiotics.

Conclusion: This first clinical analysis of synovial fluid B. burgdorferi Western blot testing found that 91% of patients diagnosed with Lyme arthritis based upon this laboratory test did not satisfy standard diagnostic criteria and lacked the expected therapeutic response to antibiotics. Synovial fluid B. burgdorferi Western blot testing should not be used to diagnose Lyme disease. Unless validation studies prove otherwise, reliance solely on this test may lead to significant antibiotic use without efficacy.

Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Sam S. Barclay , Imperial College School of Medicine, London, England
Paul Auwaerter, MD, FIDSA , Division of Infectious Diseases and General Internal Medicine, Johns Hopkins University, Baltimore, MD
Michael T. Melia, MD , Johns Hopkins University School of Medicine, Baltimore, MD


S. S. Barclay, None

P. Auwaerter, None

M. T. Melia, None

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 21 with the exception of research findings presented at IDSA press conferences.


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