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Higher C6 enzyme immunoassay index values correlate with a diagnosis of noncutaneous Lyme disease. Diagn Microbiol Infect Dis 2019 Jun;94(2):160-164



Pubmed ID




Scopus ID

2-s2.0-85059810141   8 Citations


The correlation between the Food and Drug Administration-cleared C6 enzyme immunoassay (EIA) C6 index values and a diagnosis of Lyme disease has not been examined. We used pooled patient-level data from 5 studies of adults and children with Lyme disease and control subjects who were tested with the C6 EIA. We constructed a receiver operating characteristic curve using regression clustered by study and measured the area under the curve (AUC) to examine the accuracy of the C6 index values in differentiating between patients with noncutaneous Lyme disease and control subjects. In the 4821 included patients, the C6 index value had excellent ability to distinguish between patients with noncutaneous Lyme disease and control subjects [AUC 0.99; 95% confidence interval (CI) 0.99-1.00]. An index value cut point of ≥3.0 had a sensitivity of 90.9% (95% CI, 87.8-93.3) and specificity of 99.0% (95% CI, 98.6-99.2%) for Lyme disease.

Author List

Nigrovic LE, Lipsett SC, Molins CR, Wormser GP, Bennett JE, Garro AC, Levas MN, Balamuth F, Neville D, Lingampalli N, Robinson WH, Branda JA


Michael Levas MD Associate Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Complement C6
Immunoenzyme Techniques
Lyme Disease
ROC Curve
Sensitivity and Specificity
Serologic Tests