Molecular-based diagnosis of multiple sclerosis and its progressive stage

OBJECTIVE

Biomarkers aid diagnosis, allow inexpensive screening of therapies, and guide selection of patient-specific therapeutic regimens in most internal medicine disciplines. In contrast, neurology lacks validated measurements of the physiological status, or dysfunction(s) of cells of the central nervous system (CNS). Accordingly, patients with chronic neurological diseases are often treated with a single disease-modifying therapy without understanding patient-specific drivers of disability. Therefore, using multiple sclerosis (MS) as an example of a complex polygenic neurological disease, we sought to determine whether cerebrospinal fluid (CSF) biomarkers are intraindividually stable, cell type-, disease- and/or process-specific, and responsive to therapeutic intervention.

METHODS

We used statistical learning in a modeling cohort (n = 225) to develop diagnostic classifiers from DNA-aptamer-based measurements of 1,128 CSF proteins. An independent validation cohort (n = 85) assessed the reliability of derived classifiers. The biological interpretation resulted from in vitro modeling of primary or stem cell-derived human CNS cells and cell lines.

RESULTS

The classifier that differentiates MS from CNS diseases that mimic MS clinically, pathophysiologically, and on imaging achieved a validated area under the receiver operating characteristic curve (AUROC) of 0.98, whereas the classifier that differentiates relapsing-remitting from progressive MS achieved a validated AUROC of 0.91. No classifiers could differentiate primary progressive from secondary progressive MS better than random guessing. Treatment-induced changes in biomarkers greatly exceeded intraindividual and technical variabilities of the assay.

INTERPRETATION

CNS biological processes reflected by CSF biomarkers are robust, stable, disease specific, or even disease stage specific. This opens opportunities for broad utilization of CSF biomarkers in drug development and precision medicine for CNS disorders. Ann Neurol 2017;82:795-812.

[Application of long term video electroencephalogram and resting-state functional magnetic resonance imaging in detection of cognition in patients with benign epilepsy of childhood with centrotemporal spikes]

Objective: To study the relationship between the changes of brain network and cognition in patients with benign epilepsy of childhood with centrotemporal spikes (BECTS) by using long term video electroencephalogram (VEEG) and resting-state functional magnetic resonance imaging (RS-fMRI) technology. Methods: Eleven patients with right-handed were recruited (from April 2015 to September 2016) from epilepsy specialist outpatients and functional department of neurosurgery of Tianjin Medical University General Hospital. They all underwent the long term VEEG monitoring (one sleep cycle was included at least). According to the spike-wave index (SWI) during slow ware sleep, they were divided into two groups: SWI<50% (5 cases) and SWI≥50% (6 cases). All the patients were assessed with cognitional test including language, execution, memory and attention. They also underwent the head MRI, RS-fMRI examinations. Then the results were comparatively analysed. Results: (1)There were no statisticaly significance in sex, age, age of onset, disease course, total number of seizures, years of education (P>0.05). The Full Intelligence Quotient (FIQ) (87±18), Verbal Intelligence Quotient (VIQ) (88±15) and Performance Intelligence Quotient (PIQ) (89±20) of SWI≥50% group were lower than SWI<50% group(118±8, 114±11, 119±5) and the differences were statistically significant(P<0.05). (2)There was a negative correlation between the FIQ (P=0.002), VIQ (P=0.006), PIQ (P=0.001) and SWI. The FIQ, VIQ and PIQ had no correlation with the sex, age, age of onset, disease course, total number of seizures, years of education (P>0.05). (3)Compared with SWI<50% group, SWI≥50% group showed increased regional homogeneity (ReHo) in the bilateral precentral gyrus, premotor area and the subcortical structure, the right temporal lobe and the bilateral insular lobe(P<0.05); while they showed decreased ReHo in the posterior cingulate gyrus, right posterior inferior temporal lobe and right occipital lobe(P<0.05). Conclusion: The change of the brain network which is caused by the paradoxical and constant discharge during slow ware sleep in patients with BECTS may affect the development of cognition.

Molecular-based diagnosis of Multiple Sclerosis and its progressive stage

Biomarkers aid diagnosis, allow inexpensive screening of therapies and guide selection of rational patient-specific polypharmacy regimens in most internal medicine disciplines. In contrast, there are no clinically-validated measurements of the physiological status, or dysfunction(s) of cellular components of the central nervous system (CNS). Accordingly, patients with chronic neurological diseases are generally treated with a single disease-modifying therapy without understanding patient-specific drivers of disability.

Therefore, using multiple sclerosis (MS) as an example of a complex polygenic neurological disease, we sought to determine if cerebrospinal fluid (CSF) biomarkers are intra-individually stable, cell type-, disease- and/or process-specific and responsive to therapeutic intervention.

Using DNA-aptamer-based multiplex assay, in-vitro- and statistical models, we developed in a training cohort (n=225) and validated in an independent-cohort (n=85) two biomarker-based classifiers that differentiate: 1. MS from CNS diseases that mimic MS clinically, pathophysiologically and on imaging, and 2. relapsing-remitting from progressive MS with ~90% accuracy. Treatment-induced changes in biomarkers greatly exceeded intra-individual-and technical variabilities of the assay.

The observation that CNS biological processes reflected by combinatorial CSF biomarkers are robust, stable and disease- or even disease-stage specific opens opportunities for broad utilization of CSF biomarkers in drug development and precision medicine for CNS disorders.

Systemic arterial stiffness in infants with bronchopulmonary dysplasia: potential cause of systemic hypertension

OBJECTIVE

Systemic hypertension is common among preterm infants with severe bronchopulmonary dysplasia (BPD); the exact cause is unknown. The objective of this preliminary hypothesis generating study was to examine systemic arterial structure and vasomotor function in a cohort of preterm infants with severe BPD, using a cohort of preterm infants without BPD and a cohort of term infants for comparison.

STUDY DESIGN

After obtaining informed consent, we measured aortic wall thickness and vasomotor function by ultrasonography in 20 infants with severe BPD, 7 infants with no BPD, and compared them with 20 healthy term infants.

RESULTS

Maximum aortic thickness was significantly higher in infants with BPD (827±163 μm) compared to those with no BPD (674±22 μm) and term infants (657±67 μm) (unadjusted P<0.0001). The input impedance was similarly elevated in the infants with BPD (574±127 dynes s( )cm(-5)) compared to those with no BPD (325±24 dynes s cm(-)(5)) or term infants (328±113 dynes s cm(-)(5)) (unadjusted P<0.0001). Stiffness index was significantly higher in the infants with BPD (3.4±0.6) compared to those with no BPD (2.6±0.3) or term infants (2.3±0.4) (unadjusted P<0.0001). Systemic vascular resistance was also significantly elevated in the infants with BPD. The results remained significant even after adjusting for gestational age and birth weight. Measures of vasomotor function significantly correlated with blood pressure.

CONCLUSION

The aortic wall thickness and vasomotor function are significantly altered in preterm infants with severe BPD. These findings may explain the higher incidence of systemic hypertension in this population.

Development of Immunoassays for the Quantitative Assessment of Amyloid-β in the Presence of Therapeutic Antibody: Application to Pre-Clinical Studies

Utilizing decision making biomarkers in drug development requires thorough assay validation. Special considerations need to be taken into account when monitoring biomarkers using immunoassays in the presence of therapeutic antibodies. We have developed robust and sensitive assays to assess target engagement and proof of mechanism to support the clinical progression of a human monoclonal antibody against the neurotoxic amyloid-β (Aβ)₄₂ peptide. Here we present the introduction of novel pre-treatment steps to ensure drug-tolerant immunoassays and describe the validation of the complete experimental procedures to measure total Aβ₄₂ concentration (bound and unbound) in cerebrospinal fluid (CSF) and plasma, free Aβ₄₂ concentration (unbound) in CSF, and Aβ₄₀ concentration in CSF. The difference in composition of the matrices (CSF and plasma) and antigen levels therein, in combination with the hydrophobic properties of Aβ protein, adds to the complexity of validation. Monitoring pharmacodynamics of an Aβ₄₂ specific monoclonal antibody in a non-human primate toxicology study using these assays, we demonstrated a 1500-fold and a 3000-fold increase in total Aβ₄₂ in plasma, a 4-fold and 8-fold increase in total Aβ₄₂ in CSF together with a 95% and 96% reduction of free Aβ₄₂ in CSF following weekly intravenous injections of 10 mg/kg and 100 mg/kg, respectively. Levels of Aβ₄₀ were unchanged. The accuracy of these data is supported by previous pre-clinical studies as well as predictive pharmacokinetic/pharmacodynamics modeling. In contrast, when analyzing the same non-human primate samples excluding the pre-treatment steps, we were not able to distinguish between free and total Aβ₄₂. Our data clearly demonstrate the importance of thorough evaluation of antibody interference and appropriate validation to monitor different types of biomarkers in the presence of a therapeutic antibody.

Investigation of serum IGF-I levels amongst diabetic and non-diabetic cats

Since insulin-like growth factor-I (IGF-I) was first discovered as a mediator of glucose homeostasis, it has been extensively investigated in diabetes research in humans, rodents and primates. To date, however, relatively little work has been carried out on this hormone in the cat, despite the pathophysiological similarities between human and feline diabetes mellitus, as well as the relatively common nature of the disease in cats. This study reports on the IGF-I concentrations of 42 insulin treated diabetic cats and 25 normal cats. Diabetic subjects were grouped according to length of insulin treatment as either short, medium or long term. Analysis of variance (ANOVA) and Fischer's pair-wise comparisons revealed that mean IGF-I levels in short-term diabetic cats were significantly lower than those in normal cats whilst mean levels in long-term diabetics were significantly higher. The direction and extent of these alterations may have implications for our understanding of the pathophysiology of feline diabetes mellitus and for the use of this hormone in the diagnosis of acromegaly in diabetic cats.

Primary spinal oligoastrocytoma mimicking longitudinally extensive transverse myelitis

Longitudinally extensive transverse myelitis (LETM) is most commonly associated with neuromyelitis optica spectrum disorders (NMOSD). However, a wide range of etiologies may produce longitudinally extensive spinal cord lesions (LESCLs) on imaging. We highlight the case of a patient with a spinal cord tumor whose imaging showed LESCL and was diagnosed with LETM. He did not respond to immunosuppression and subsequently developed a progressive and protracted clinical course. Thoracic cord biopsy performed 6 years after symptom onset showed primary spinal oligoastrocytoma. We discuss the features that should raise suspicion of a neoplasm in the context of LESCL and serve a reminder that not all LESCLs are inflammatory.

Chemical Composition, In vivo Digestibility and Metabolizable Energy Values of Caramba (Lolium multiflorum cv. caramba) Fresh, Silage and Hay

The experiment was conducted to determine nutritive values of caramba (Lolium multiflorum cv. caramba) fresh, silage and hay by in vivo and in vitro methods. There was a statistically significant difference (p<0.01) in crude protein content value between fresh caramba (12.83%) and silage (8.91%) and hay (6.35%). According to results of experiment, the crude fiber, neutral detergent fiber, acid detergent fiber (ADF), acid detergent lignin contents of the three forms of caramba varied between 30.22% to 35.06%, 57.41% to 63.70%, 35.32% to 43.29%, and 5.55% to 8.86% respectively. There were no significant differences between the three forms of caramba in digestibility of nutrients and in vivo metabolizable energy (ME) values (p>0.05). However, the highest ME_CN (ME was estimated using crude nutrients) and ME_ADF values were found in fresh caramba (p<0.01). As a result, it could be said that, there were no differences between the three forms of caramba in nutrient composition, digestibility and ME value, besides drying and ensiling did not affect digestibility of hay. Consequently, caramba either as fresh, silage or hay is a good alternative source of forage for ruminants.