Clinical Phenotype of a First Unprovoked Acute Pulmonary Embolism Associated with Antiphospholipid Antibody Syndrome

Abstract

BackgroundAntiphospholipid antibody syndrome (APS), an important cause of acquired thrombophilia, is diagnosed when vascular thrombosis or pregnancy morbidity occurs with persistently positive antiphospholipid antibodies (aPL). APS is a risk factor for unprovoked recurrence of pulmonary embolism (PE). Performing laboratory testing for aPL after a first unprovoked acute PE is controversial. We investigated if a specific phenotype existed in patients with unprovoked with acute PE, suggesting the need to evaluate them for APS.MethodsWe retrospectively reviewed patients with PE and APS (n=24) and those with unprovoked PE with aPL negative (n=44), evaluated 2006–2016 at the Asan Medical Center. We compared patient demographics, clinical manifestations, laboratory findings, and radiological findings between the groups.ResultsOn multivariate logistic regression analysis, two models of independent risk factors for APS-PE were suggested. Model I included hemoptysis (odds ratio [OR], 12.897; 95% confidence interval [CI], 1.025–162.343), low PE severity index (OR, 0.948; 95% CI, 0.917–0.979), and activated partial thromboplastin time (aPTT; OR, 1.166; 95% CI, 1.040–1.307). Model II included age (OR, 0.930; 95% CI, 0.893–0.969) and aPTT (OR, 1.104; 95% CI, 1.000–1.217).ConclusionWe conclude that patients with first unprovoked PE with hemoptysis and are age <40; have a low pulmonary embolism severity index, especially in risk class I–II; and/or prolonged aPTT (above 75th percentile of the reference interval), should be suspected of having APS, and undergo laboratory testing for aPL.

Antiphospholipid Syndrome-Related Pulmonary Embolism: Clinical Characteristics and Early Recognition

“…In this study, there were more low-risk patients observed in the APS-PE group, especially in triple positive aPLs patients. This was consistent with previous studies, which found 62.5% of low-risk patients in the APS-PE group and only 29.5% in the non-APS-PE group ( 19 ). Therefore, the aPLs test should not be ignored for patients with low-risk pulmonary embolism.…”

“…Consistent with previous studies ( 19 ), prolonged APTT was an indicator of APS in young PE patients. The LA antibody may inhibit the formation of prothrombinase complexes, leading to prolonged APTT ( 32 ).…”

“…The average age of the APS-PE group was 39.7 years, while the average age of the non-APS-PE group was 60.4 years (19), which could be related to the younger age of APS onset (4,20). Therefore, aPLs should be tested in patients younger than 40 years old who first experienced symptomatic PE or in young patients (<50 years old) with unexplained thrombotic events at an abnormal site or in patients who suffered from pregnancy complications (19,21,22). Compared to patients without thrombosis, there was a higher proportion of males in APS patients with thrombosis and arterial thrombosis complications (23).…”

“…The average age of patients with primary APS who experienced their first thrombotic event was younger than 50 years old (18). The average age of the APS-PE group was 39.7 years, while the average age of the non-APS-PE group was 60.4 years (19), which could be related to the younger age of APS onset (4,20). Therefore, aPLs should be tested in patients younger than 40 years old who first experienced symptomatic PE or in young patients (<50 years old) with unexplained thrombotic events at an abnormal site or in patients who suffered from pregnancy complications (19,21,22).…”

Incidence and Risk Factors of Recurrent Venous Thromboembolism after Pulmonary Embolism

“…Third, the time in therapeutic range of the international normalized ratio was not available for assessing the degree of quality control in the study. Fourth, antiphospholipid syndrome is an important risk factor for an increased risk for the first and recurrent VTE343536. However, in this study, the test for antiphospholipid antibody was rarely performed and excluded from the variables for risk factors.…”