Predictive value of Thomsen-Friedenreich antigen activation for Streptococcus pneumoniae infection and severity in pediatric lobar pneumonia

Abstract Background Most cases of complicated pneumonia in children are caused by pneumococcal infections. Thomsen-Friedenreich antigen (TA) is present on erythrocytes, platelets and glomeruli, and it can be activated during pneumococcal infection. The aim of this study was to investigate the predictive value of TA activation for pneumococcal infection and association with the severity of complicated pneumonia. Materials and methods Patients with lobar pneumonia were routinely tested for TA at the Department of Pediatrics, Mackay Memorial Hospital from January 2010 to December 2015. We retrospectively reviewed and analyzed their charts and data including age, sex, etiology of infection, chest tube insertion or video-assisted thoracoscopic surgery, length of hospital stay, TA activation, white blood cell count and level of C reactive protein. Results A total of 142 children with lobar pneumonia were enrolled, including 35 with empyema, 31 with effusion, 11 with necrotizing pneumonia and four with lung abscess. Streptococcus pneumoniae was the most commonly identified pathogen. Twenty-two patients (15.4%) had activated TA, all of whom were infected with S . pneumoniae . TA activation had 100% specificity and 100% positive predictive value for pneumococcal infection. In the multivariate analysis in lobar pneumonia, TA activation (OR, 15.8; 95% CI, 3.0–83.5; p  = 0.001), duration of fever before admission (OR, 1.2; 95% CI, 1.1–1.5; p  = 0.013) and initial CRP level (OR, 1.1; 95% CI, 1.0–1.1; p  = 0.004) were independent predictors of empyema. Conclusions TA activation is a specific marker for pneumococcal pneumonia and might indicate higher risk for complicated pneumonia.