Antiphospholipid Antibody Syndrome With Valvular Vegetations in Acute Q Fever

Clin Infect Dis. 2016 Mar 1;62(5):537-44. doi: 10.1093/cid/civ956. Epub 2015 Nov 18.

Abstract

Background: Coxiella burnetii endocarditis is considered to be a late complication of Q fever in patients with preexisting valvular heart disease (VHD). We observed a large transient aortic vegetation in a patient with acute Q fever and high levels of IgG anticardiolipin antibodies (IgG aCL). Therefore, we sought to determine how commonly acute Q fever could cause valvular vegetations associated with antiphospholipid antibody syndrome, which would be a new clinical entity.

Methods: We performed a consecutive case series between January 2007 and April 2014 at the French National Referral Center for Q fever. Age, sex, history of VHD, immunosuppression, and IgG aCL assessed by enzyme-linked immunosorbent assay were tested as potential predictors.

Results: Of the 759 patients with acute Q fever and available echocardiographic results, 9 (1.2%) were considered to have acute Q fever endocarditis, none of whom had a previously known VHD. After multiple adjustment, very high IgG aCL levels (>100 immunoglobulin G-type phospholipid units; relative risk [RR], 24.9 [95% confidence interval {CI}, 4.5-140.2]; P = .002) and immunosuppression (RR, 10.1 [95% CI, 3.0-32.4]; P = .002) were independently associated with acute Q fever endocarditis.

Conclusions: Antiphospholipid antibody syndrome with valvular vegetations in acute Q fever is a new clinical entity. This would suggest the value of systematically testing for C. burnetii in antiphospholipid-associated cardiac valve disease, and performing early echocardiography and antiphospholipid dosages in patients with acute Q fever.

Keywords: Coxiella burnetii; Q fever; antiphospholipid antibodies; valvular heart disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Anticardiolipin / blood
  • Antiphospholipid Syndrome / etiology*
  • Antiphospholipid Syndrome / immunology
  • Coxiella burnetii
  • Endocarditis, Bacterial / etiology*
  • Endocarditis, Bacterial / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Follow-Up Studies
  • Heart Valve Diseases / etiology*
  • Heart Valve Diseases / immunology
  • Heart Valve Diseases / microbiology
  • Heart Valve Diseases / pathology
  • Heart Valves / pathology
  • Humans
  • Immunoglobulin G / immunology
  • Male
  • Middle Aged
  • Pregnancy
  • Pregnancy Complications, Infectious / microbiology
  • Q Fever / complications*
  • Q Fever / immunology
  • Treatment Outcome

Substances

  • Antibodies, Anticardiolipin
  • Immunoglobulin G