Rituximab for Pediatric Central Nervous System Inflammatory Disorders in Alberta, Canada.

BACKGROUND: Early and effective treatment of central nervous system (CNS) inflammatory disorders is vital to reduce neurologic morbidity and improve long-term outcomes in affected children. Rituximab is a B-cell-depleting monoclonal antibody whose off-label use for these disorders is funded in the province of Alberta, Canada, by the Short-Term Exceptional Drug Therapy (STEDT) program. This study describes the use of rituximab for pediatric CNS inflammatory disorders in Alberta. METHODS: Rituximab applications for CNS inflammatory indications in patients <18 years of age were identified from the STEDT database between January 1, 2012, and December 31, 2019. Patient information was linked to other provincial datasets including the Discharge Abstract Database, Pharmaceutical Information Network, and Provincial Laboratory data. Analysis was descriptive. RESULTS: Fifty-one unique rituximab applications were identified, of which 50 were approved. New applications increased from one in 2012 to a high of 12 in 2018. The most common indication was autoimmune encephalitis without a specified antibody (n = 16, 31%). Most children were approved for a two-dose (n = 33, 66%) or four-dose (n = 16, 32%) induction regimen. Physician-reported outcomes were available for 24 patients, of whom 14 (58%) were felt to have fully met outcome targets. CONCLUSION: The use of rituximab for pediatric CNS inflammatory disorders has increased, particularly for the indication of autoimmune encephalitis. This study identified significant heterogeneity in dosing practices and laboratory monitoring. Standardized protocols for the use of rituximab in these disorders and more robust outcome reporting will help better define the safety and efficacy of rituximab in this population.

ARF1-related disorder: phenotypic and molecular spectrum.

PURPOSE: ARF1 was previously implicated in periventricular nodular heterotopia (PVNH) in only five individuals and systematic clinical characterisation was not available. The aim of this study is to provide a comprehensive description of the phenotypic and genotypic spectrum of ARF1-related neurodevelopmental disorder. METHODS: We collected detailed phenotypes of an international cohort of individuals (n=17) with ARF1 variants assembled through the GeneMatcher platform. Missense variants were structurally modelled, and the impact of several were functionally validated. RESULTS: De novo variants (10 missense, 1 frameshift, 1 splice altering resulting in 9 residues insertion) in ARF1 were identified among 17 unrelated individuals. Detailed phenotypes included intellectual disability (ID), microcephaly, seizures and PVNH. No specific facial characteristics were consistent across all cases, however microretrognathia was common. Various hearing and visual defects were recurrent, and interestingly, some inflammatory features were reported. MRI of the brain frequently showed abnormalities consistent with a neuronal migration disorder. CONCLUSION: We confirm the role of ARF1 in an autosomal dominant syndrome with a phenotypic spectrum including severe ID, microcephaly, seizures and PVNH due to impaired neuronal migration.

Detailed genetic analysis of feeding behaviour in Romane lambs and links with residual feed intake.

Breeding strategies based on feed efficiency are now implemented in most animal species using residual feed intake (RFI) criteria. Although relevant, the correlated responses of feeding behaviour traits resulting from such selection on RFI are poorly documented. We report the estimated feeding behaviour at three time levels (visit, meal and day) and genetic parameters between the feeding behaviour traits and their links with RFI and its components. Feed intake, feeding duration at three time levels (per visit, meal and day), feeding rate, number of visits and time-between-visits were estimated for 951 Romane lambs fed via automatic concentrate feeders. Heritability estimates of feeding behaviour traits ranged from 0.19 to 0.54 with higher estimates for the day level than the visit level. Daily feed intake was not genetically linked to feed intake at the visit level, whereas feeding duration between visit and day levels was moderately correlated (Rg  = +0.41 ± 0.12). RFI was not significantly correlated with feeding rate, but was positively linked to feed intake and feeding duration at the day level (+0.73 ± 0.09 and +0.41 ± 0.13, respectively) and negatively at the visit level (-0.33 ± 0.14 and -0.22 ± 0.17, respectively). Selecting animals with lower RFI values might modify their feeding behaviour by increasing feed intake and feeding duration at the visit level but decrease the number of visits per day (+0.51 ± 0.14).

Plasma and ovarian oestradiol and the variability in the LH surge induced in ewes by the ram effect.

The proportion of anoestrous ewes ovulating after exposure to a sexually active ram is variable mainly due to whether an LH surge is induced. The aim of this study was to determine the role of oestradiol (E2) in the ram-induced LH surge. In one study, we measured the plasma concentrations of E2 in ewes of different breeds before and after the 'ram effect' and related these patterns to the presence and latency of the LH surge, while another compared ovarian responses with the 'ram effect' following exposure to rams for 2 or 12 h. In all ewes, the concentration of E2 increased 2-4 h after rams were introduced and remained elevated for 14.5 ± 0.86 h. The quantity of E2 secreted before the LH surge varied among breeds as did the mean concentration of E2. The granulosa cells of IF ewes collected after 12 h exposure to rams secreted more E2 and progesterone and had higher levels of StAR than the 2 h group but in MV ewes there was no differences between these groups for any of these parameters. These results demonstrate that the LH surge induced by the rams is a result of increased E2 secretion associated with increased levels of STAR in granulosa cells and that these responses varied among breeds. The results suggest that the variable occurrence of a LH surge and ovulation may be the result of variable ovarian responses to the 'ram effect' and insensitivity of the hypothalamus to the E2-positive feedback signal.

Identification of QTLs for behavioral reactivity to social separation and humans in sheep using the OvineSNP50 BeadChip.

BACKGROUND: Current trends in sheep farming practices rely on animals with a greater level of behavioral autonomy than before, a phenotype that actively contributes to the sustainability of animal production. Social reactivity and reactivity to humans are relevant behavioral traits in sheep, known for their strong gregariousness and weak tolerance to handling, which have previously been reported with moderate to high heritabilities. To identify loci underlying such behaviors, we performed a genome study in Romane lambs. RESULTS: The experiment was carried out on 934 male and female lambs allocated into 9 half-sib families (average of 103 lambs per family) and reared outside. After weaning, all the lambs were individually exposed to 4 standardized behavioral tests combining social isolation, exposure to humans or handling, confinement and novelty (i.e. arena test, corridor test, isolation box test, shearing test). A broad range of behaviors including vocalizations, locomotion, vigilance and flight distance, as well as the cortisol response to handling, were collected. All lambs were genotyped using the Illumina OvineSNP50 BeadChip. QTL detection was performed by linkage, association and joint linkage and association analyses using the QTLmap software. Five main QTL regions were identified on sheep chromosomes (Ovis Aries Region, OAR) 12, 16, 19, 21 and 23 among many other QTLs with small to moderate effects. The QTLs on OAR12, 16 and 21 showed significant associations with social reactivity. The QTLs on OAR19 and 23 were found to be associated with reactivity to humans. No overlapping QTLs were identified for the different traits measured in the behavioral tests, supporting the hypothesis that different genetic factors influence social reactivity and tolerance to humans. CONCLUSION: The results of this study using ovine SNP data suggest that in domestic sheep the behavioral responses to social separation and exposure to humans are under polygenic influence. The most relevant QTLs reported in the present study contain interesting candidate genes previously described to be associated with various emotional and social behaviors in mammals.

Impaired functionality and homing of Fancg-deficient hematopoietic stem cells.

Fanconi anemia (FA) is a human rare genetic disorder characterized by congenital defects, bone marrow (BM) failure and predisposition to leukemia. The progressive aplastic anemia suggests a defect in the ability of hematopoietic stem cells (HSC) to sustain hematopoieis. We have examined the role of the nuclear FA core complex gene Fancg in the functionality of HSC. In Fancg-/- mice, we observed a decay of long-term HSC and multipotent progenitors that account for the reduction in the LSK compartment containing primitive hematopoietic cells. Fancg-/- lymphoid and myeloid progenitor cells were also affected, and myeloid progenitors show compromised in vitro functionality. HSC from Fancg-/- mice failed to engraft and to reconstitute at short and long term the hematopoiesis in a competitive transplantation assay. Fancg-/- LSK cells showed a loss of quiescence, an impaired migration in vitro in response to the chemokine CXCL12 and a defective homing to the BM after transplantation. Finally, the expression of several key genes involved in self-renewal, quiescence and migration of HSC was dysregulated in Fancg-deficient LSK subset. Collectively, our data reveal that Fancg should play a role in the regulation of physiological functions of HSC.

Comparison of the data mining and machine learning algorithms for predicting the final body weight for Romane sheep breed.

The current study aimed to predict final body weight (weight of fourth months of age to select the future reproducers) by using birth weight, birth type, sex, suckling weight, age at suckling weight, weaning weight, age at weaning weight, and age of final body weight for the Romane sheep breed. For this purpose, classification and regression tree (CART), multivariate adaptive regression splines (MARS), and support vector machine regression (SVR) algorithms were used for training (80%) and testing (20%) sets. Different data mining and machine learning algorithms were used to predict final body weight of 393 Romane sheep (238 female and 155 male animals) were used with different artificial intelligence algorithms. The best prediction model was obtained by CART model, both training and testing set. Constructed CART models indicated that sex, suckling weight, weaning weight, age of weaning weight, and age of final weight could be used as an indirect selection measure to get a superior sheep flock on the final body weight of Romane sheep. If genetically established, the Romane sheep whose sex is female, age of final weight is over 142 days, and weaning weight is over 28 kg could be chosen for affording genetic improvement in final body weight. In conclusion, the usage of CART procedure may be worthy of reflection for identifying breed standards and choosing superior sheep for meat yield in France.

Fetal hippocampal development: analysis by magnetic resonance imaging volumetry.

The hippocampal formation plays an important role in learning and memory; however, data on its development in utero in humans are limited. This study was performed to evaluate hippocampal development in healthy fetuses using 3D reconstructed MRI. A cohort of 20 healthy pregnant women underwent prenatal MRI at a median GA of 24.9 wk (range, 21.3-31.9 wk); six of the women also had a second fetal MRI performed at a 6-wk interval. Routine 2D ultrafast T2-weighted images were used to reconstruct a 3D volume image, which was then used to manually segment the right and left hippocampi. Total hippocampal volume was calculated for each subject and compared against GA. There was a linear increase in total hippocampal volume with increasing GA (p < 0.001). For subjects scanned twice, there was an increase in hippocampal size on the second fetal MRI (p = 0.0004). This represents the first volumetric study of fetal hippocampal development in vivo. This normative volumetric data will be helpful for future comparison studies of suspected developmental abnormalities of hippocampal structure and function.

Heterogeneity of variance components for preweaning growth in Romane sheep due to the number of lambs reared.

BACKGROUND: The pre-weaning growth rate of lambs, an important component of meat market production, is affected by maternal and direct genetic effects. The French genetic evaluation model takes into account the number of lambs suckled by applying a multiplicative factor (1 for a lamb reared as a single, 0.7 for twin-reared lambs) to the maternal genetic effect, in addition to including the birth*rearing type combination as a fixed effect, which acts on the mean. However, little evidence has been provided to justify the use of this multiplicative model. The two main objectives of the present study were to determine, by comparing models of analysis, 1) whether pre-weaning growth is the same trait in single- and twin-reared lambs and 2) whether the multiplicative coefficient represents a good approach for taking this possible difference into account. METHODS: Data on the pre-weaning growth rate, defined as the average daily gain from birth to 45 days of age on 29,612 Romane lambs born between 1987 and 2009 at the experimental farm of La Sapinière (INRA-France) were used to compare eight models that account for the number of lambs per dam reared in various ways. Models were compared using the Akaike information criteria. RESULTS: The model that best fitted the data assumed that 1) direct (maternal) effects correspond to the same trait regardless of the number of lambs reared, 2) the permanent environmental effects and variances associated with the dam depend on the number of lambs reared and 3) the residual variance depends on the number of lambs reared. Even though this model fitted the data better than a model that included a multiplicative coefficient, little difference was found between EBV from the different models (the correlation between EBV varied from 0.979 to 0.999). CONCLUSIONS: Based on experimental data, the current genetic evaluation model can be improved to better take into account the number of lambs reared. Thus, it would be of interest to evaluate this model on field data and update the genetic evaluation model based on the results obtained.

Patterns of Brain Injury in Perinatal Arterial Ischemic Stroke and the Development of Infantile Spasms.

INTRODUCTION: Perinatal arterial ischemic stroke (PAIS) underlies approximately 10% of infantile spasms (IS). We aim to identify patterns of brain injury in ischemic stroke that may predispose infants to infantile spasms. METHODS: Sixty-four perinatal arterial ischemic stroke patients were identified meeting the following inclusion criteria: term birth, magnetic resonance imaging (MRI) showing ischemic stroke or encephalomalacia in an arterial distribution, and follow-up records. Patients who developed infantile spasms (PAIS-IS) were analyzed descriptively for ischemic stroke injury patterns and were compared to a seizure-free control group (PAIS-only). Stroke injury was scored using the modified pediatric ASPECTS (modASPECTS). RESULTS: The PAIS-IS (n = 9) group had significantly higher modASPECTS than the PAIS-only (n = 16) group (P = .002, Mann-Whitney). A greater proportion of PAIS-IS patients had injury to deep cerebral structures (67%) than PAIS-only (25%). CONCLUSION: Infarct size was significantly associated with infantile spasms development. Results support theories implicating deep cerebral structures in infantile spasms pathogenesis. This may help identify perinatal arterial ischemic stroke patients at risk of infantile spasms, facilitating more timely diagnosis.

High frequency of anti-protein Z antibodies in patients with anticardiolipin antibodies.

Protein Z (PZ) is a vitamin K-dependent protein involved in the down-regulation of coagulation by forming a complex with the protein Z-dependent protease inhibitor. The complex inhibits the activated factor X on phospholipid surface. Presence of anti-PZ (aPZ) antibodies was first described in women with pathological pregnancies but the significance of aPZ antibodies in other pathological situations was poorly studied. In this work we analyzed the frequency of aPZ antibodies in a series of 86 consecutive patients with anticardiolipin (aCL) antibodies and studied the association of aPZ with other antiphospholipid (aPL) antibodies [lupus anticoagulant (LAC) and anti-ß2GP-1 antibodies] and the clinical signification of these aPZ antibodies in term of thrombosis or fetal loss. Anti-PZ antibodies (IgG and IgM) were detected using commercially available ELISA assays. The frequency of aPZ antibodies was 40.7% in the patient group versus 6.8% in a group of 59 healthy volunteers (p < 0.0001). The frequency of aPZ antibodies significantly increases (p < 0.05) in patients with a double or triple positivity of aPL antibodies and a higher frequency of aPZ antibodies was observed in patients with LAC (57.7%) than in patients without LAC (25.6%, p = 0.02). There were no significant differences in aPZ antibodies frequency between patients with and without thrombotic events. Interestingly, among the 8 women with recurrent foetal losses, aPZ antibodies were observed in 7 cases, in agreement with previous observations suggesting that aPZ antibodies may be associated with obstetrical complications.

Longitudinal Study of Irradiation-Induced Brain Microstructural Alterations With S-Index, a Diffusion MRI Biomarker, and MR Spectroscopy.

PURPOSE: Radiation therapy is widely used for the treatment of brain tumors, but it may lead to severe cognitive impairments. Previous studies have shown that ionizing irradiation induces demyelination, blood-brain barrier alterations, and impaired neurogenesis in animal models. Hence, noninvasive and sensitive biomarkers of irradiation injury are needed to investigate these effects in patients and improve radiation therapy protocols. METHODS AND MATERIALS: The heads of 3-month-old male C57BL/6RJ mice (15 control mice and 15 irradiated mice) were exposed to radiation doses of 3 fractions of 5 Gy from a 60Co source with a medical irradiator. A longitudinal study was performed to investigate cranial irradiation-induced (3 fractions of 5 Gy) microstructural tissue alterations using water diffusion magnetic resonance imaging and magnetic resonance spectroscopy in different areas of the mouse brain (cortex, thalamus, striatum, olfactory bulbs [OBs], hippocampus, and subventricular zone [SVZ]). In addition to the quantification of standard non-Gaussian diffusion parameters, apparent diffusion coefficient (ADC0) and kurtosis (K), we evaluated a new composite diffusion metric, designated the S-index (ie, "signature index"). RESULTS: We observed a significant decrease in the S-index in the SVZ from 1 month to 8 months after brain irradiation (P < .05). An interesting finding was that, along with a decrease in taurine levels (up to -15% at 2 months, P < .01), a delayed S-index drop was observed in the OBs from 4 months after irradiation and maintained until the end of our experiment (P < .0001). These observations suggest that S-index variations revealed the irradiation-induced decline of neurogenesis that was further confirmed by a decrease in neural stem cells in the SVZ and in newborn neurons in the OBs of irradiated animals. CONCLUSIONS: This study demonstrates that diffusion magnetic resonance imaging, especially through the S-index approach, is a relevant imaging modality to monitor brain irradiation injury and probe microstructural changes underlying irradiation-induced cognitive deficits.

Severe prekallikrein deficiencies due to homozygous C529Y mutations.

Two consecutive severe prekallikrein deficiencies were investigated. The first was identified in a 63-year-old patient admitted for ischemic stroke. The second deficiency was identified in a 38-year-old patient admitted for a second-trimester pregnancy loss. A homozygous C529Y mutation was identified for both cases, whereas they are unrelated and no consanguineous marriage is known from the patients. These data point to a possible high frequency of this mutation as a cause of prekallikrein deficiency.

Prothrombin Suresnes: a case of homozygous F299V mutation responsible for hypodysprothrombinemia.

A patient with a severe prothrombin deficiency and a hemorrhagic diathesis was found to have positive cross-reactive material in plasma and a homozygous F299V mutation (F7V in the A chain). This mutation reinforces the previous conclusion that the A chain affects the geometry of the catalytic triad. Marked prolongation of the Taipan venom and Russell venom clotting times also demonstrated a defective activation mechanism and a defective interaction with factor Xa.

Decreased levels of procoagulant phospholipids in bleeding patients treated by vitamin K antagonists.

International Normalized Ratio (INR) is currently used to monitor vitamin K antagonist therapy, and the bleeding incidence becomes exponential for INR>4.5. Inversely, more than 50% of patients with a supratherapeutic INR are asymptomatic. Therefore it could be of interest to identify patients with a higher bleeding risk. Microparticles derived from different cell types express procoagulant phospholipids (PPL) which can be evaluated by a chronometric coagulation assay where a shortening of the clotting times is associated with increased levels of PPL. In a series of 174 consecutive patients referred to our Emergency Department with an INR>5, median level of PPL was significantly (p=0.004) lower (38.2s) in the 119 asymptomatic patients than in patients with nonmajor (43.6s, n=35) or major bleeding (46.6s, n=19), indicating higher levels of procoagulant phospholipids in asymptomatic patients. By receiver operating characteristic curve analysis, a cut-off of 43.5s discriminated patients with higher haemorrhagic risk (area under the curve=0.648). In contrast, thrombomodulin levels, quantified either by immunological or functional assays were not significantly different between both groups. In conclusion, evaluation of PPL could be of interest to define the haemorrhagic risk of VKA- treated patients.

Factor XI deficiency: identification of six novel missense mutations (P23L, P69T, C92G, E243D, W497C and E547K).

Factor XI (FXI) deficiency is a rare coagulation disorder associated with bleeding of variable severity but without a clear relationship between bleeding and FXI levels. This study reports the molecular genetic analysis of FXI deficiencies in thirteen patients. Six novel missense mutations were identified: P23L, P69T, C92G, E243D, W497C and E547K.