Mycoplasma pneumoniae​ pneumonia associated thrombosis at Beijing Children’s Hospital

Abstract

Background: With the increase of awareness of mycoplasma pneumoniae pneumonia (MPP), we found thrombosis in severe MPP (SMPP) was not rare. The aim of the study was to investigate the clinical characteristics, treatment, and long-term prognosis of MPP-associated thrombosis. Methods: We retrospectively reviewed the medical records of 43 children with MPP-associated thrombosis between January 2013 and June 2019 at Beijing Children’s Hospital. The results of blood coagulation studies, autoimmune antibody, thrombophilia screening, contrast-enhanced lung computed tomography, echocardiography, and blood vessel ultrasonography were analyzed, as were treatment outcomes. Results: Forty-two patients were diagnosed with SMPP. D-dimer was higher than 5.0 mg/L in 58.1% (25/43) of patients. The mean D-dimer level was 11.1 ± 12.4 mg/L. Anticardiolipin-IgM was positive in 60.0% of patients, β2-glycoprotein-IgM in 64.0%, and lupus anticoagulant in 42.1%. Chest imaging revealed pulmonary consolidation with lobe distribution in all patients (2/3–1 lobe in 10 patients, > 1 lobe in 29 patients). In our experience, thrombosis can occur in a vessel of any part of the body, and it can be initially detected as late as 31 days after disease onset. Thrombosis in the brain and abdomen can occur early, at 5 days after disease onset. Pulmonary vessels were the most commonly involved sites in the current study, and accordingly chest pain was the most common symptom (32.6%), followed by neurological symptoms (14.0%) and abdominal pain (9.3%). Thirty-five percent of patients were asymptomatic with regard to thrombosis. All patients underwent anticoagulant therapy, and thrombus absorption took > 3 months in most patients. All patients were followed until October 2019, at which time 41 were asymptomatic and 2 had mild recurrent cough. Conclusions: SMPP with pulmonary consolidation (> 2/3 lobe) was the most strongly associated risk factor for thrombosis. Thrombosis-associated symptoms may be subtle, even absent. Elevated D-dimer, specifically > 11.1 mg/L (even > 5.0mg/L), would assist in the early diagnosis of thrombosis. The long-term prognosis of thrombosis was good after timely administration of anticoagulant therapy.

Clinical significance of D-dimer level in refractory Mycoplasma pneumoniae pneumonia

“…Regarding complications, previous studies have reported that the D-D level was positively correlated with extrapulmonary complications in pediatric patients with MPP [21]; however, extensive research on the D-D level and complications has not been reported to date. In a previous study, a higher D-D level was associated with more extensive and serious thrombosis [4]. Our results show that elevated levels of D-D had a good predictive ability for pleural effusion and liver injury and that the incidence of pleural effusion increased with increasing levels of D-D, but there was no signi cant difference between the moderately elevated group and the severely elevated group.…”

“…Refractory M. pneumoniae pneumonia (RMPP) has become increasingly common in recent years. RMPP frequently shows no improvement in clinical and radiological ndings despite appropriate macrolide treatment and even present with necrotizing pneumonia, airway occlusion, or thrombosis [4]. The speci c pathogenesis of RMPP remains unclear, and pathogenic substances or other host factors may be the cause of lung injury associated with an excessively strong immune response [5][6][7][8].…”

“…Several cases of MPP complicated with thrombus have recently been reported [4,15], indicating that children with MPP have abnormal coagulation. The serum D-dimer (D-D) level can be used as a molecular marker for hypercoagulability [4], as well as an indicator for monitoring in ammation and severe infection, such as coronavirus disease 2019(Covid-19) [16]. The present study further explored the role of hypercoagulability in the pathogenesis of RMPP by evaluating D-D levels and changes in D-D levels in children with MPP.…”

An Unusual Case of Myocarditis, Left Ventricular Thrombus, and Embolic Stroke Caused by Mycoplasma pneumoniae

“…Besides lung involvement, patients may develop several extra-pulmonary manifestations including cardiovascular, dermatological, gastrointestinal, hematological, and neurological involvement [2]. Thrombosis, especially cardiac thrombosis associated with M. pneumonia, is extremely rare [3,4]. We present such an unusual case of M. pneumoniae infection presenting with left ventricular thrombus and an embolic stroke in an adult.…”

Clinical significance of D-dimer level in refractory Mycoplasma pneumoniae pneumonia

“…pneumoniae pneumonia (RMPP) has become increasingly common in recent years. RMPP frequently shows no improvement in clinical and radiological ndings despite appropriate macrolide treatment and even present with necrotizing pneumonia, airway occlusion, or thrombosis [4]. The speci c pathogenesis of RMPP remains unclear, and pathogenic substances or other host factors may be the cause of lung injury associated with an excessively strong immune response [5][6][7][8].…”