SARS-CoV-2 antibody research in patients with unprovoked pulmonary embolism in COVID-19 pandemic period.

OBJECTIVE: Due to the coronavirus disease 2019 (COVID-19) pandemic, a significant increase has been observed in patients diagnosed with pulmonary embolism (PE) in our clinic. In addition to COVID-19-related PE, the increase in the number of patients with unprovoked or idiopathic PE was also noteworthy. Although it is not surprising that PE due to immobilization was observed in elderly patients and patients with comorbidities at risk for PE during the pandemic, it is important to investigate the increase in the number of unprovoked PE. Thus, we aimed to show that a previous COVID-19 infection may be a risk factor in these patients by examining the presence of severe acute respiratory syndrome-causing coronavirus (SARS-CoV-2) antibodies in patients diagnosed with unprovoked PE. MATERIALS AND METHODS: The participants of the study consisted of 45 consecutive patients who were diagnosed with PE in our clinic, had no risk factors for PE, were considered unprovoked (idiopathic) PE, and had no history of COVID-19. SARS-CoV-2 antibody titers were measured in the serum samples of the patients for detecting immunity as a result of encountering COVID-19. RESULTS: Of the 45 patients diagnosed with PE, 24 (53.3%) patients were diagnosed with computed tomography pulmonary angiogram (CTPA), and 21 (46.7%) patients were diagnosed with perfusion single-photon emission computed tomography (Q-SPECT/CT). Immunity acquired after encountering COVID-19 was checked with the NCP kit, which revealed positive results in 9 (20%) patients. CONCLUSION: It should be kept in mind that some of the patients diagnosed with idiopathic PE during the pandemic may have embolism due to asymptomatic COVID-19. In addition, it is now known that COVID-19 also creates a tendency toward thrombosis in asymptomatic patients.

Investigation of perfusion defects by Q-SPECT/CT in patients with mild-to-moderate course of COVID-19 and low clinical probability for pulmonary embolism.

OBJECTIVE: Pulmonary embolism is a severe source of mortality and morbidity in patients with severe and critical coronavirus disease 2019. It is not yet clear whether the tendency to thrombosis is increased in the mild-to-moderate course of COVID-19. Our research aims to show the clinical benefit of Q-SPECT/CT in diagnosing PD in outpatients treated with mild-to-moderate course of COVID-19 and to determine the frequency of perfusion defects in these patients having relatively lower risk. METHODS: All patients who underwent Q-SPECT/CT with suspicion of embolism were examined retrospectively. Only patients with low clinical probability and mild-to-moderate course of COVID-19 for PE were included in the study. The patients were evaluated comparatively as those with and without perfusion defects. Patients were divided into laboratory suspicion, clinical suspicion, or clinical and laboratory suspicion. RESULTS: In outpatients with mild-to-moderate COVID-19 with low clinical probability for PE, PD without CT abnormality was detected with a rate of 36.6% with Q-SPECT/CT performed for complaints of high D-dimer and/or dyspnea. None of the patients had PD at more proximal level than the segment level. PD with no concomitant CT abnormality was observed with a rate of 56.5% in patients with both clinical and laboratory suspicion. For D-dimer = 0.5 mg/dL cut-off sensitivity is 85%, for D-dimer = 1.5 mg/dL cut-off specificity 81%. CONCLUSION: Thrombosis tendency is also present in outpatients with mild-to-moderate COVID-19, and these patients should also be offered anticoagulant prophylaxis during the COVID-19 period.