Serology in chronic Q fever is still surrounded by question marks.

Abstract

Detection of antibodies using immunofluoresence tests (IFAT) is recommended for diagnosis of chronic Q fever, but other commercial antibody assays are also available. We compared an enzyme-linked immunosorbent assay (ELISA) (Virion/Serion) and a complement fixation test (CFT) (Virion/Serion) for the detection of Coxiella burnetii IgG phase I and IgA phase I in early- and follow-up serum samples from patients with chronic Q fever, diagnosed according to an algorithm that involves IFAT. For this, we tested sera of 49 patients, including 30 proven, 14 probable and five possible chronic Q fever cases. Sensitivity of CFT for diagnosis of chronic Q fever was suboptimal (85 %), as eight patients, including five with chronic Q fever, tested negative at time of diagnosis, whereas IgG phase I antibodies were detected in these five patients by ELISA. Sensitivity of ELISA was higher, although three probable patients were missed. No differences in ELISA IgA phase I detection between proven chronic Q fever and probable were observed; instead possible patients were in majority IgA negative (60 %). Serological examination using ELISA and CFT in follow-up sera from 26 patients on treatment was unsatisfactory. Like IFAT, all kinetic options were possible: decreasing, remaining stable or even increase during time. This study demonstrated that the sensitivity of CFT-based phase I antibody detection is low and therefore not recommended for diagnosis of chronic Q fever. Based on our results, serological follow-up to guide treatment decisions was of limited value.

• Authors: M C A Wegdam-Blans, H T Tjhie, J M Korbeeck, M N Nabuurs-Franssen, L M Kampschreur, T Sprong, J A W Teijink, M P Koopmans
• Journal: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (Eur J Clin Microbiol Infect Dis) Vol. 33 Issue 7 Pg. 1089-94 (Jul 2014) ISSN: 1435-4373 [Electronic] Germany
• PMID: 24430618 (Publication Type: Comparative Study, Evaluation Study, Journal Article)

Chemical References

• Antibodies, Bacterial
• Immunoglobulin A
• Immunoglobulin G

Topics

• Antibodies, Bacterial (blood)
• Complement Fixation Tests (methods)
• Coxiella burnetii (immunology)
• Enzyme-Linked Immunosorbent Assay (methods)
• Fluorescent Antibody Technique
• Humans
• Immunoglobulin A (blood)
• Immunoglobulin G (blood)
• Q Fever (diagnosis, immunology)
• Sensitivity and Specificity