The prognostic value of serological titres for clinical outcomes during treatment and follow-up of patients with chronic Q fever.

Abstract

OBJECTIVES:

We assessed the prognostic value of phase I IgG titres during treatment and follow-up of chronic Q fever.

METHODS:

We performed a retrospective cohort study to analyse the course of phase I IgG titres in chronic Q fever. We used a multivariable time-varying Cox regression to assess our primary (first disease-related event) and secondary (therapy failure) outcomes. In a second analysis, we evaluated serological characteristics after 1 year of therapy (fourfold decrease in phase I IgG titre, absence of phase II IgM and reaching phase I IgG titre of ≤1:1024) with multivariable Cox regression.

RESULTS:

In total, 337 patients that were treated for proven (n = 284, 84.3%) or probable (n = 53, 15.7%) chronic Q fever were included. Complications occurred in 190 (56.4%), disease-related mortality in 71 (21.1%) and therapy failure in 142 (42.1%) patients. The course of phase I IgG titres was not associated with first disease-related event (HR 1.00, 95% CI 0.86-1.15) or therapy failure (HR 1.02, 95% CI 0.91-1.15). Similar results were found for the serological characteristics for the primary (HR 0.97, 95% CI 0.62-1.51; HR 1.12, 95% CI 0.66-1.90; HR 0.99, 95% CI 0.57-1.69, respectively) and secondary outcomes (HR 0.86, 95% CI 0.57-1.29; HR 1.37, 95% CI 0.86-2.18; HR 0.80, 95% CI 0.48-1.34, respectively).

DISCUSSION:

Coxiella burnetii serology does not reliably predict disease-related events or therapy failure during treatment and follow-up of chronic Q fever. Alternative markers for disease management are needed, but, for now, management should be based on clinical factors, PCR results, and imaging results.

• Authors: Sheila B Buijs, Sonja E van Roeden, Cornelis H van Werkhoven, Andy I M Hoepelman, Peter C Wever, Chantal P Bleeker-Rovers, Jan Jelrik Oosterheert
• Journal: Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases (Clin Microbiol Infect) Vol. 27 Issue 9 Pg. 1273-1278 (Sep 2021) ISSN: 1469-0691 [Electronic] England
• PMID: 33813120 (Publication Type: Journal Article)
• Copyright: Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Chemical References

• Antibodies, Bacterial
• Immunoglobulin G
• Immunoglobulin M

Topics

• Antibodies, Bacterial (blood)
• Coxiella burnetii
• Follow-Up Studies
• Humans
• Immunoglobulin G (blood)
• Immunoglobulin M (blood)
• Prognosis
• Q Fever (diagnosis, drug therapy)
• Retrospective Studies