There are no specific diagnostic laboratory findings associated with non-bacterial thrombotic endocarditis. Tests are usually conducted to detect the underlying cause of NBTE and differentiate it from infective endocarditis;.

• There are no specific diagnostic laboratory findings associated with non-bacterial thrombotic endocarditis.
• The following laboratory tests are usually conducted to detect the underlying cause of NBTE and differentiate it from infective endocarditis;

• CBC: may show neutrophilia and anemia
• Prothrombin time, partial thromboplastin time, fibrinogen, thrombin time, D-dimers, and cross-linked fibrin degradation products (abnormal values may depict DIC).

• Multiple blood cultures (minimum to 3 blood cultures prior to antibiotic use) to rule out infective endocarditis and other infectious etiologies^[1].

• Antinuclear antibodies (SLE screening)
• Anti-dsDNA antibodies (SLE confirmation and to monitor the progress of disease and lupus nephritis)
• Anti-Smith antibodies
• Anti-RNP
• Antiphospholipid antibodies
• Anticardiolipin antibodies (associated with an increased risk of cardiac abnormalities)
• Anti-Ro/SSA
• Anti-La/SSB
• False-positive serology in the form of VDRL is also common in SLE

The following inflammatory markers are often elevated

• C-reactive protein
• Erythrocyte sedimentation rate (ESR)

• PCR is a rapid and reliable method to detect the culture-negative endocarditis by fastidious organisms^[4][5].