Antiphospholipid Antibody Syndrome With Valvular Vegetations in Acute Q Fever

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.

Mouse Model of Coxiella burnetii Aerosolization

“…Atzpodien et al described myocardium, endocardium, and valvular inflammatory infiltrates 10 days after peritoneal infection, resolving at day 150 (13,39,42). Interestingly, C. burnetiirelated transient endocarditis has recently been published in humans combined with antiphospholipid syndrome (39). Here, nonimmunosuppressed animals appeared to clear the bacterial infection and develop self-limited disease, whereas immunosuppressed animals reached the limit point at 2 months p.i.…”

“…In line with clinical patterns (37), our model was able to produce cardiac infections compatible with the valvular affinity of C. burnetii in immunosuppressed animals, even in the absence of preexisting valvular disease. Cardiac involvement has been well described in guinea pigs (38) and after intraperitoneal infection in mice (39). Originally, we described C. burnetii endocarditis 2 months after aerosol infection in mice (13).…”

“…Originally, we described C. burnetii endocarditis 2 months after aerosol infection in mice (13). Atzpodien et al described myocardium, endocardium, and valvular inflammatory infiltrates 10 days after peritoneal infection, resolving at day 150 (13,39,42). Interestingly, C. burnetiirelated transient endocarditis has recently been published in humans combined with antiphospholipid syndrome (39).…”

Thrombosis and antiphospholipid antibody syndrome during acute Q fever

“…[1] Cardiovascular complications are the main risk of C burnetii infection, including acute and chronic endocarditis and vascular infections. [1,2] During primary infection, antiphospholipid antibodies and specifically IgG anticardiolipin antibodies (IgG aCL) are highly prevalent (57 to 80%) and are associated with fever, thrombocytopenia, valvular heart disease, and progression toward chronic endocarditis. [3–5] This prevalence is characteristic of acute Q fever since prevalence is only 1% to 5% in the general population and 10% to 30% in other infections including HCV and parvovirus B19.…”

No Such Thing as Chronic Q Fever

“…Use of the term chronic to define cardiovascular infections in patients with Q fever is misleading. Indeed, valvular vegetations were recently reported in acute Q fever ( 8 ). Q fever vascular infections must be distinguished in the context of mycotic aneurisms, small saccular and embolic consequences of endocarditis that may go unnoticed, and underlying vascular disease.…”