Is It Antiphospholipid Syndrome?

The diagnosis of bacterial endocarditis remains a challenge, as nearly half of cases develop in the absence of preexistent heart disease and known risk factors. Not infrequently, a blunted clinical course at onset can lead to erroneous diagnoses. We present the case of a 47-year-old previously healthy man in which a presumptive diagnosis of antiphospholipid syndrome was made based on the absence of echocardiographically detected heart involvement, a negative blood culture, normal C-reactive protein (CRP) levels, a positive lupus anticoagulant (LAC) test, and evidence of splenic infarcts. The patient eventually developed massive aortic endocarditic involvement, with blood cultures positive for Streptococcus bovis, and was referred for valvular replacement. This case not only reminds us of the diagnostic challenges of bacterial endocarditis, but also underlines the need for a critical application of antiphospholipid syndrome diagnostic criteria. 1. Introduction Antiphospholipid syndrome (APS) and infective endocarditis (IE) are difficult-to-diagnose diseases and share several clinical features. To increase the probability of excluding temporary infection-associated antibodies, current diagnostic criteria for APS require Antiphospholipid Antibodies (APA) positivity on two separate occasions at least twelve weeks apart [1]. We describe here the case of a 47-year-old male in whom an erroneous diagnosis of presumptive APS, waiting for confirmatory laboratory test, was made, leading to a potentially dangerous delay in the treatment of infective endocarditis. The diagnostic challenges presented by this patient are discussed. 2. Case Report A 47-year-old previously healthy man was admitted to our department because of arthralgias, remittent fever, and pericardial effusion. His medical history was unremarkable. Approximately one year earlier he had had an episode of paroxysmal atrial fibrillation with pharmacological restoration of sinus rhythm. For the past six months before admission, he reported remittent low-grade fever, tachycardia, night sweats, cervical pain, and migratory arthralgias with transient joint swelling. The patient was evaluated by an internal medicine specialist. Blood test revealed WBC 7.000/mmc, Hb 14.0？g/dL, and C-reactive protein (CRP) 9.3？mg/L. C3 and C4 complement components were within normal limits, and antinuclear antibodies were absent. A small IgG-K monoclonal gammopathy (7.94？g/L) was detected, with negative Bence-Jones proteinuria. A blood culture was negative. Silica clotting time, lupus anticoagulant (LAC) screening (LAR 1.97),