anti - neutrophil cytoplasmic antibodies ( ancas ) correlate well with a wide spectrum of vasculitis manifestations , including wegener 's granulomatosis , microscopic polyangiitis , and churg - strauss syndrome , all of which are commonly referred to as anca - associated vasculitis ( 1 ) .
several infections , particularly infective endocarditis , have been reported to show positive findings on anca tests ; furthermore , their clinical features have been acknowledged to mimic anca - associated vasculitis , which may lead to a misdiagnosis and inappropriate treatment ( 2,3 ) .
however , to our knowledge , infected aortic aneurysms have not been reported to show positive findings on anca tests .
we herein report a patient with an infected thoracic aortic aneurysm mimicking anti - proteinase 3-antineutrophil cytoplasmic antibody ( pr3-anca)-associated vasculitis .
vegetations in the descending aorta , which were detected using transesophageal echocardiography , contributed to the diagnosis in this case .
a woman in her 60s was admitted to the nagoya city university hospital complaining of a fever , which had persisted for three weeks , along with a loss of appetite , proteinuria , hematuria , and renal dysfunction .
her renal function test values had been in the normal range three months prior to the admission .
she also had a history of orbital mucosa - associated lymphoid tissue lymphoma , which was in remission after treatment with only radiation therapy .
a physical examination at the time of admission revealed a body temperature of 38.1 , pulse rate 109 beats / min , and blood pressure 104/53 mmhg .
the laboratory tests revealed a white blood cell count of 18,900/mm , hemoglobin 6.6 g / dl , blood urea nitrogen 30.8 mg / dl , serum creatinine 2.24 mg / dl , and c - reactive protein ( crp ) 9.44 mg / dl ( table ) .
the pr3-anca titer was 47.4 iu / ml ( normal range < 10 iu / ml ) , although her myeloperoxidase - antineutrophil cytoplasmic antibody ( mpo - anca ) titer was not elevated .
a urinalysis gave results of 2 + for protein and 3 + for occult blood in a dipstick examination , and a microscopic examination detected more than 100 red blood cells per high - power field .
alt : alanine aminotransferase , ana : antinuclear antibodies , ast : aspartate transaminase , c3 : compliment 3 , c4 : compliment 4 , ch50 : 50% hemolytic unit of complement , crp : c - reactive protein , dna : deoxyribonucleic acid , ldh : lactate dehydrogenase , mpo - anca : myeloperoxidase - antineutrophil cytoplasmic antibody , rf : rheumatic factor , pr3-anca : anti - proteinase 3-antineutrophil cytoplasmic antibody she was initially diagnosed with pr3-anca - associated vasculitis and was thereafter treated with methylprednisolone pulse therapy ( 500 mg / day ) for three days ( fig .
however , streptococcus sanguis was serially detected in blood cultures ; therefore , the administration of steroids was stopped .
transesophageal echocardiography also revealed no vegetation in the heart ; however , it showed many oscillating masses attached to the intima in the descending aorta ( fig .
2 ) . contrast - enhanced computed tomography ( ct ) revealed a new descending aortic aneurysm ( fig .
effects of antibiotics on fever and c - reactive protein during hospitalization . the patient finally became afebrile and has c - reactive protein levels within the normal range after receiving antibiotics .
crp : c - reactive protein , dap : daptomycin , pcg : penicillin g , taz / pipc : tazobactam / piperacillin , tx : therapy transesophageal echocardiographic images of the descending aorta , with sectioning planes at 90 ( a ) and 0 ( b ) .
many oscillating masses attached to the intima were seen in the lumen of the descending aorta .
contrast - enhanced computed tomographic images in the axial ( a ) and frontal ( b ) sections .
these images show a descending aortic pseudoaneurysm and a contrast defect ( arrow ) beside the aneurysm that is compatible with echo - documented vegetation .
based on the results of microbiological testing , antibiotic treatment with intravenous penicillin g ( 24,000,000 unit / day ) was started , after which she became afebrile .
we added intravenous daptomycin ( 300 mg every 24 hours ) and tazobactam / piperacillin ( 2.25 g every 6 hours ) to the penicillin g because recurrent fever was observed two weeks later .
this additional antibiotic treatment made her afebrile again , and her renal function was recovered ( fig .
, she developed a janeway lesion , which was confirmed by the pathological finding of a skin biopsy specimen ( fig .
4 ) . transesophageal echocardiography finally demonstrated that the vegetation had disappeared after the antibiotic treatment ( fig .
5 ) , but contrast - enhanced ct revealed that the aneurysm remained unchanged in form . a nontender hemorrhagic macular on the sole of the foot ( a ) .
photomicrograph of the macular lesion shows microembolization with fibrin and infiltration of neutrophilic cells hematoxylin and eosin staining ( b , c ) .
a transesophageal echocardiographic image of the descending aorta after the antibiotic treatment , with the sectioning plane at 90. many oscillating masses have disappeared . on the 54th hospital day , she underwent endovascular aortic repair ( evar ) of the aneurysm ( fig .
6 ) after confirmation that her crp level was in the normal range and once blood cultures were consistently negative .
one year after the procedure , she continues to take oral antibiotics ; no complications related to stent - graft deployment or recurrent infections have been encountered .
her pr3-anca titer has normalized . a contrast - enhanced computed tomographic image after endovascular stent graft repair .
in this case , an infected aortic aneurysm exhibited elevated the patient 's pr3-anca level , and its clinical course mimicked pr3-anca - associated vasculitis .
the detection of ancas is highly specific for a diagnosis of anca - associated vasculitis ( 4 ) ; however , a number of infections can result in a positive anca test .
there are several reports of infective endocarditis with the presence of ancas that mimic the clinical manifestations of an anca - associated vasculitis such as glomerulonephritis ( 2,3 ) . in the present case , based on the finding of positive blood cultures
, we suspected that the patient was experiencing not anca - associated vasculitis but infective endocarditis .
however , no vegetations were detected in the cardiac chambers using transthoracic echocardiography or transesophageal echocardiography .
instead , contrast - enhanced ct revealed a pseudoaneurysm in the descending aorta , which suggested that the patient had an infected aneurysm .
her renal dysfunction and elevated pr3-anca levels normalized with clinical resolution of the infected aneurysm after the administration of appropriate antibiotic therapy and evar .
the patient has remained free of any evidence of systemic vasculitis during follow - up .
the presence of pr3-anca may have been falsely positive in the present patient . to our knowledge , this is the first report of an infected aortic aneurysm with a positive pr3-anca test and clinical features mimicking anca - associated vasculitis .
the presence of vegetations in the heart is one of the most characteristic findings of infective endocarditis .
these vegetations are composed of bacteria , platelets , and inflammatory cells interspersed with fibrin mesh , either on damaged endocardium , including native cardiac valves , or prosthetic valves ( 5 ) . in the present case ,
because these masses disappeared after antibiotic treatment , they were considered to be vegetations . a pathological examination of the macular hemorrhages on the patient 's sole indicated not a cholesterol embolization but rather a janeway lesion , which was the consequence of septic embolic events .
we therefore suspected that these masses were not mobile plaques but bacterial vegetations . to our knowledge ,
few cases of infected native aortic aneurysm manifesting vegetations in the aneurysm have been reported ( 6 - 8 ) .
several mechanisms have been proposed regarding how ancas are formed during the course of infection , such as autoantigen complementarity , molecular mimicry , epigenetics , neutrophil extracellular traps , and microbial - sensing proteins called toll - like receptors ( 9 ) . there may be a great degree of overlap in the clinical and laboratory manifestations between anca - associated vasculitis and anca - positive infected aortic aneurysm , potentially leading to a misdiagnosis .
it is important to correctly diagnose these cases in order to avoid administering inappropriate therapy , such as immunosuppressive treatment , which might have life - threatening consequences in a patient with an infected aortic aneurysm .
positive blood cultures and imaging findings , such as a pseudoaneurysm and/or vegetations in the aorta , suggest the presence of an infected aortic aneurysm . a combination of conventional surgical treatment with resection of the aneurysm , extensive local debridement , and revascularization by in situ reconstruction or extra - anatomic bypass may be the gold standard , but such a treatment strategy is accompanied by a high mortality and morbidity . in the present case ,
it was recently reported that evar of an infected aortic aneurysm is feasible and , for most patients , a durable treatment option ( 10 ) .
given that the continuous administration of antibiotics for the infected aneurysm should prevent a recurrence of local infection , we continued using antibiotics until the infection was controlled and carefully monitored the shape of the pseudoaneurysm on contrast - enhanced ct .
we were ready to perform an emergency surgical correction at any point during this patient 's treatment course . in conclusion
, we herein reported an unusual case of infected descending aortic pseudoaneurysm with luminal pathognomonic oscillating vegetation and with serological findings and clinical features mimicking pr3-anca - associated vasculitis .
 we herein report an unusual case of an infected descending aortic pseudoaneurysm with luminal pathognomonic oscillating vegetation with serological findings and clinical features mimicking anti - proteinase 3-antineutrophil cytoplasmic antibody - associated vasculitis . the positive blood cultures and imaging findings , including a pseudoaneurysm and vegetations in the aorta , suggested the presence of an infected aortic aneurysm . 
 the patient was successfully treated with antibiotics and endovascular aortic repair . 
 a precise diagnosis is crucial in order to avoid inappropriate therapy such as immunosuppressive treatment , which could result in life - threatening consequences in a patient with an infected aortic aneurysm . 
Introduction
Case Report
Discussion
The authors state that they have no Conflict of Interest (COI).