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 > 5.0 mg/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 levels in refractory Mycoplasma pneumoniae pneumonia

“…In recent years, the prevalence of RMPP has been increasing, particularly in Asian countries [ 2 , 6 ]. Clinical cases of MPP complicated with thrombosis are not unusual, and MPP complicated with deep vein thrombosis is frequently reported [ 4 , 15 ]. At present, the mechanism by which MPP causes vascular embolization is not fully understood, and it is primarily considered to be related to immune mediation after vascular injury [ 17 ].…”

“…Refractory M. pneumoniae pneumonia (RMPP) has become increasingly common in recent years. RMPP frequently shows no improvement in clinical and radiological findings despite appropriate macrolide treatment and even present with necrotizing pneumonia, airway occlusion, or thrombosis [ 4 ]. The specific 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 – 8 ].…”

“…There is no specificity in early clinical manifestations of RMPP, and early diagnosis is difficult; therefore, early predictors need to be identified. 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 inflammation and severe infection, such as coronavirus disease 2019(Covid-19) [ 16 ].…”

“…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 inflammation 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.…”

The Efficacy of High-frequency Chest Wall Oscillation (HFCWO) for the Improvement of Symptoms in Children with Mycoplasma pneumoniae

“…pneumoniaeinfection can lead to inflammatory edema in the airways, thus causing the tracheal wall to thicken; this effect is exacerbated by the accumulation of sputum. These factors can have an adverse effect on recovery time (20). Previous research also reported that M. pneumoniae adhesion inducesthe synthesis of hydrogen peroxide; this endogenous form of reactive oxygen species (ROS) can cause oxidative stress damage (21).…”