Blood Test Could Detect Abusive Head Trauma in Infants

A blood test has been developed and refined that could help clinicians identify infants who may have had bleeding of the brain as a result of abusive head trauma, sometimes referred to as shaken baby syndrome.

Approximately 30% of abusive head trauma (AHT) diagnoses are missed when caretakers provide inaccurate histories or when infants have nonspecific symptoms such as vomiting or fussiness. Missed diagnoses can be catastrophic as AHT can lead to permanent brain damage and even death.

A team of scientists working with the Children's Hospital of Pittsburgh performed a retrospective study on a cohort of 99 patients followed by a prospective cohort of 599 patients to derive and validate the Biomarkers of Infant Brain Injury Score. The Biomarkers of Infant Brain Injury Score predicted intracranial hemorrhage with a higher sensitivity than clinical judgment, the current criterion standard.

Binary logistic regression was used to develop a multivariable model incorporating three serum biomarkers, matrix metallopeptidase-9, neuron-specific enolase, and vascular cellular adhesion molecule-1, and one clinical variable, total hemoglobin. The model was then prospectively validated. Multiplex biomarker measurements were performed using Flow-Thru microarray technology on the Ziplex System, which has potential as a point-of-care system. The Axela's automated testing system allowed the researchers to measure multiple biomarkers simultaneously using an extremely small amount of blood, an important characteristic of a test designed to be used in infants.

The test correctly detected acute intracranial hemorrhage because of abusive head trauma approximately 90% of the time, a much higher rate than the sensitivity of clinical judgement, which is approximately 70%. The specificity of the test was 48% and the sensitivity was 89.3%. The team aimed for the test to be highly sensitive rather than maximizing accuracy, since missing a diagnosis has more serious consequences than performing brain imaging in babies without the condition.

The authors concluded that The Biomarkers for Infant Brain Injury Score, a multivariable model using three serum biomarker concentrations and serum hemoglobin, can identify infants with acute intracranial hemorrhage. Rachel Pardes Berger, MD, MPH, a senior author of the study, said, “The test is not intended to replace clinical judgement, which is crucial. Rather, we believe that it can supplement clinical evaluation and in cases where symptoms may be unclear, help physicians make a decision about whether an infant needs brain imaging.” The study was published on April 10, 2017, in the journal JAMA Pediatrics.