Role of beta-2-microglobulin as a biomarker in very preterm and extremely preterm infants with CNS inflammation.

BACKGROUND: Premature infants are at risk for severe sepsis and meningitis, both infections associated with high mortality and morbidity. Cerebro-spinal fluid (CSF) culture is the gold standard method for meningitis diagnosis, but interpretation of biochemical parameters of CSF is essential at the moment of the analysis in order to start the appropriate treatment. The main objective of this study was to determine whether levels of CSF beta-2-microglobulin (B2M) were elevated in preterm infants with CNS infections or other inflammatory processes, and to establish if there were differences in B2M concentrations amongst various inflammatory settings (sepsis, meningitis, and progressive post-hemorrhagic ventricular dilatation (PHVD)). METHODS: This is a retrospective study of all very preterm and extremely preterm infants (< 32 weeks of gestation) admitted to our NICU between 2012 and 2017. All those who underwent a lumbar puncture during their stay as part of a sepsis work-up or PHVD were considered for inclusion. CSF biochemical parameters and B2M were tested in all of the patients. RESULTS: Fifty-nine patients were included in the study. In patients with CNS infections, the median value of B2M was 8.69 mg/L (3.92-18.5). B2M levels above 3.92 mg/L showed greater sensitivity and specificity than leukocyte levels in discriminating between patients with CNS infections or other inflammatory processes and those without CNS inflammation. CONCLUSIONS: In this population, CSF B2M proved to be an effective biomarker to discriminate between patients with CNS infections and other inflammatory processes and those without CNS inflammation.

Plasticity of neonatal neuronal networks in very premature infants: Source localization of temporal theta activity, the first endogenous neural biomarker, in temporoparietal areas.

Temporal theta slow-wave activity (TTA-SW) in premature infants is a specific signature of the early development of temporal networks, as it is observed at the turning point between non-sensory driven spontaneous local processing and cortical network functioning. The role in development and the precise location of TTA-SW remain unknown. Previous studies have demonstrated that preterms from 28 weeks of gestational age (wGA) are able to discriminate phonemes and voice, supporting the idea of a prior genetic structural or activity-dependent fingerprint that would prepare the auditory network to compute auditory information at the onset of thalamocortical connectivity. They recorded TTA-SW in 26-32 wGA preterms. The rate of TTA-SW in response to click stimuli was evaluated using low-density EEG in 30 preterms. The sources of TTA-SW were localized by high-density EEG using different tissues conductivities, head models and mathematical models. They observed that TTA-SW is not sensory driven. Regardless of age, conductivities, head models and mathematical models, sources of TTA-SW were located adjacent to auditory and temporal junction areas. These sources become situated closer to the surface during development. TTA-SW corresponds to spontaneous transient endogenous activities independent of sensory information at this period which might participate in the implementation of auditory, language, memory, attention and or social cognition convergent and does not simply represent a general interaction between the subplate and the cortical plate. Hum Brain Mapp 38:2345-2358, 2017. © 2017 Wiley Periodicals, Inc.