Combinatorial Host-Response Biomarker Signature (BV Score) and Its Subanalytes TRAIL, IP-10, and C-Reactive Protein in Children With Mycoplasma pneumoniae Community-Acquired Pneumonia.

Background: Host-response biomarkers to differentiate bacterial from viral etiology in children with respiratory infections have shown high accuracies, but are understudied in Mycoplasma pneumoniae (Mp) infections.

Methods: We compared BV scores (0-34 indicating viral etiology, and 66-100 indicating bacterial etiology), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL; pg/mL), interferon-γ inducible protein 10 (IP-10; pg/mL), and C-reactive protein (CRP; mg/L) serum levels between Mp-positive (Mp+) and Mp-negative (Mp-) community-acquired pneumonia (CAP) patients. We performed receiver operating characteristic (ROC) curve analyses for clinical features and biomarkers.

Results: Of 80 CAP patients (median age, 6.3 years; 57.5% male), 26 had Mp+CAP. In Mp+CAP patients, compared to Mp-CAP patients, BV scores were lower (14.0 [3.0-27.8] vs 54.0 [12.0-84.8]; P = .0008), TRAIL levels were higher (86.5 [67.4-123.0] vs 65.5 [42.5-103.9]; P = .025), CRP levels were lower (12.9 [4.0-22.3] vs 36.7 [13.0-132.8]; P = .0019), and IP-10 levels were comparable (366.0 [150.2-603.8] vs 331.0 [154.3-878.8]; P = .73) (all median [interquartile range]). ROC analyses yielded a comparable discriminatory accuracy for the combination of age, fever duration, and duration of respiratory symptoms, with either procalcitonin or BV score (area under the ROC curve, 0.87 vs 0.86; P = .94).

Conclusions: Children with Mp+CAP have atypically low, viral levels of the BV score, underscoring the complementary role of microbiological testing.