Plasma proadrenomedullin (proADM) is a promising biomarker to predict disease severity in community-acquired pneumonia (CAP). Urinary biomarkers offer advantages over blood, including ease of collection. We evaluated the association between urinary proADM and disease severity in pediatric CAP.
We performed a prospective cohort study of children 3 months to 18 years with CAP. Urinary proADM/creatinine (Cr) was calculated. Disease severity was defined as: mild (discharged home), mild-moderate (hospitalized but not moderate-severe or severe), moderate-severe (eg, hospitalized with supplemental oxygen and complicated pneumonia) and severe (eg, vasopressors and invasive ventilation). Outcomes were examined using logistic regression within the cohort with suspected CAP and in a subset with radiographic CAP.
Of the 427 children included, higher proADM/Cr was associated with increased odds of severe disease compared with nonsevere disease [suspected CAP, odds ratio (OR) 1.02 (95% confidence interval (CI) 1.003, 1.04); radiographic CAP, OR 1.03 (95% CI 1.01, 1.06)] when adjusted for other covariates. ProADM/Cr had an area under the receiver operating characteristic curve of 0.56 (threshold 0.9 pmol/mg) to differentiate severe from nonsevere disease in suspected CAP and 0.65 in radiographic CAP (threshold 0.82 pmol/mg). Healthy controls had less proADM in their urine (median, 0.61 pmol/mg) compared with suspected (0.87 pmol/mg, P = 0.018) and radiographic (0.73 pmol/mg, P = 0.016) CAP.
Urinary proADM/Cr ratio measured at the time of emergency department visit was statistically associated with the development of severe outcomes in children with CAP, with stronger discriminatory performance in radiographic disease.