Sheila B Buijs1, Sonja E van Roeden2, Cornelis H van Werkhoven3, Andy I M Hoepelman2, Peter C Wever4, Chantal P Bleeker-Rovers5, Jan Jelrik Oosterheert2. 1. Department of Internal Medicine and Infectious Diseases, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands. Electronic address: sb.buijs1@gmail.com. 2. Department of Internal Medicine and Infectious Diseases, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands. 3. Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands. 4. Department of Medical Microbiology and Infection Control, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands. 5. Department of Internal Medicine and Infectious Diseases, Radboud Expert Centre for Q Fever, Radboud University Medical Centre, Nijmegen, the Netherlands.
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.
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: Daphne F M Reukers; Pieter T de Boer; Alfons O Loohuis; Peter C Wever; Chantal P Bleeker-Rovers; Arianne B van Gageldonk-Lafeber; Wim van der Hoek; Aura Timen Journal: Emerg Infect Dis Date: 2022-07 Impact factor: 16.126