Lumbar Cerebrospinal Fluid Biomarkers of Posthemorrhagic Hydrocephalus of Prematurity: Amyloid Precursor Protein, Soluble Amyloid Precursor Protein α, and L1 Cell Adhesion Molecule.

BACKGROUND: Intraventricular hemorrhage (IVH) is the most frequent, severe neurological complication of prematurity and is associated with posthemorrhagic hydrocephalus (PHH) in up to half of cases. PHH requires lifelong neurosurgical care and is associated with significant cognitive and psychomotor disability. Cerebrospinal fluid (CSF) biomarkers may provide both diagnostic information for PHH and novel insights into its pathophysiology. OBJECTIVE: To explore the diagnostic ability of candidate CSF biomarkers for PHH. METHODS: Concentrations of amyloid precursor protein (APP), soluble APPα (sAPPα), soluble APPß, neural cell adhesion molecule-1 (NCAM-1), L1 cell adhesion molecule (L1CAM), tau, phosphorylated tau, and total protein (TP) were measured in lumbar CSF from neonates in 6 groups: (1) no known neurological disease (n = 33); (2) IVH grades I to II (n = 13); (3) IVH grades III to IV (n = 12); (4) PHH (n = 12); (5) ventricular enlargement without hydrocephalus (n = 10); and (6) hypoxic ischemic encephalopathy (n = 13). CSF protein levels were compared using analysis of variance, and logistic regression was performed to examine the predictive ability of each marker for PHH. RESULTS: Lumbar CSF levels of APP, sAPPα, L1CAM, and TP were selectively increased in PHH compared with all other conditions (all P < .001). The sensitivity, specificity, and odds ratios of candidate CSF biomarkers for PHH were determined for APP, sAPPα, and L1CAM; cut points of 699, 514, and 113 ng/mL yielded odds ratios for PHH of 80.0, 200.0, and 68.75, respectively. CONCLUSION: Lumbar CSF APP, sAPPα, L1CAM, and TP were selectively increased in PHH. These proteins, and sAPPα, in particular, hold promise as biomarkers of PHH and provide novel insight into PHH-associated neural injury and repair.

Cerebrospinal fluid levels of amyloid precursor protein are associated with ventricular size in post-hemorrhagic hydrocephalus of prematurity.

BACKGROUND: Neurological outcomes of preterm infants with post-hemorrhagic hydrocephalus (PHH) remain among the worst in infancy, yet there remain few instruments to inform the treatment of PHH. We previously observed PHH-associated elevations in cerebrospinal fluid (CSF) amyloid precursor protein (APP), neural cell adhesion molecule-L1 (L1CAM), neural cell adhesion molecule-1 (NCAM-1), and other protein mediators of neurodevelopment. OBJECTIVE: The objective of this study was to examine the association of CSF APP, L1CAM, and NCAM-1 with ventricular size as an early step toward developing CSF markers of PHH. METHODS: CSF levels of APP, L1CAM, NCAM-1, and total protein (TP) were measured in 12 preterm infants undergoing PHH treatment. Ventricular size was determined using cranial ultrasounds. The relationships between CSF APP, L1CAM, and NCAM-1, occipitofrontal circumference (OFC), volume of CSF removed, and ventricular size were examined using correlation and regression analyses. RESULTS: CSF levels of APP, L1CAM, and NCAM-1 but not TP paralleled treatment-related changes in ventricular size. CSF APP demonstrated the strongest association with ventricular size, estimated by frontal-occipital horn ratio (FOR) (Pearson R = 0.76, p = 0.004), followed by NCAM-1 (R = 0.66, p = 0.02) and L1CAM (R = 0.57,p = 0.055). TP was not correlated with FOR (R = 0.02, p = 0.95). CONCLUSIONS: Herein, we report the novel observation that CSF APP shows a robust association with ventricular size in preterm infants treated for PHH. The results from this study suggest that CSF APP and related proteins at once hold promise as biomarkers of PHH and provide insight into the neurological consequences of PHH in the preterm infant.

Biological and environmental factors as predictors of language skills in very preterm children at 5 years of age.

OBJECTIVE: Language problems are thought to occur more frequently in very preterm children compared with healthy term born children. The primary aim of this study was to examine the contributions of biological and environmental risk factors to language outcomes in very preterm children at 5 years of age. METHODS: A cohort of 227 very preterm infants (birth weight <1250 g or gestational age <30 weeks) were recruited at birth and followed up at 2 and 5 years of age (corrected for prematurity) in a prospective, longitudinal study in Melbourne, Australia. Outcomes at 5 years of age were the Expressive and Receptive Language Scales from the Kaufman Survey of Early Academic and Language Skills. A range of hypothesized biological and environmental factors identified from past research were examined as predictors of language outcomes at 5 years of age using linear regression models. RESULTS: Lower maternal education and poorer communication skills in the child at 2 years of age were predictive of poorer expressive and poorer receptive language outcomes at 5 years of age. Lower expressive language scores were also associated with the presence of moderate-severe white matter abnormalities on neonatal magnetic resonance imaging. CONCLUSIONS: Results support the role of both biological and environmental factors in the evolution of language difficulties and highlight the need to consider these factors in the follow-up of preterm infants.