Background
Levels of serum D-dimer (D-D) in children with mycoplasma pneumoniae pneumonia (MPP) were assessed to explore the clinical significance of D-D level in refractory MPP(RMPP).
Method:
A total of 430 patients with MPP were enrolled between January 2015 and December 2015, and divided into a genera MPP (GMPP) group (n = 306) and a RMPP group (n = 124). Clinical data, D-D level, white blood cell (WBC) count, C-reactive protein (CRP), blood sedimentation (ESR), and lactate dehydrogenase (LDH) were compared between the two groups.
Results
(1) Hospitalization time, fever duration, WBC, CRP, LDH, ESR, and D-D were significantly higher in the RMPP group than in the GMPP group, (all P < 0.05). (2) Correlation analysis showed that D-D was positively correlated with WBC, CRP, ESR, and LDH, and could be used to jointly evaluate the severity of the disease. (3) The predictive values of WBC, CRP, ESR, LDH, and D-D for RMPP were further compared using area under the receiver operating characteristic curve(AUC) analysis. D-D had the highest predictive power for RMPP (AUC = 0.923, P < 0.01). When the D-D level was > 738 ng/ml, the predicted sensitivity of RMPP occurrence was 79.8% and the specificity was 93.5%. D-D level also had a good ability to predict pleural effusion and liver injury (AUC = 0.740, P < 0.01 and AUC = 0.812, P < 0.01, respectively). (4) After 1 week of treatment, the levels of D-D in both groups were lower than those before treatment (p < 0.01), but remained outside the normal range in 91.4% of participants, and were moderately or severely increased in 27.1% of the participants, all of whom were in the RMPP group.
Conclusion
Serum D-D levels were significantly increased in patients with RMPP, indicating that severe hypercoagulability and vascular endothelial injury with prolonged duration existed in this patient population. Increased levels of serum D-D may be used as an early predictor of RMPP and the occurrence of complications. Our findings provide a theoretical basis for the early diagnosis of RMPP, early intervention of hypercoagulability, and improvement of microcirculation therapy.