LUBAC is essential for embryogenesis by preventing cell death and enabling haematopoiesis.

The linear ubiquitin chain assembly complex (LUBAC) is required for optimal gene activation and prevention of cell death upon activation of immune receptors, including TNFR1 1 . Deficiency in the LUBAC components SHARPIN or HOIP in mice results in severe inflammation in adulthood or embryonic lethality, respectively, owing to deregulation of TNFR1-mediated cell death2-8. In humans, deficiency in the third LUBAC component HOIL-1 causes autoimmunity and inflammatory disease, similar to HOIP deficiency, whereas HOIL-1 deficiency in mice was reported to cause no overt phenotype9-11. Here we show, by creating HOIL-1-deficient mice, that HOIL-1 is as essential for LUBAC function as HOIP, albeit for different reasons: whereas HOIP is the catalytically active component of LUBAC, HOIL-1 is required for LUBAC assembly, stability and optimal retention in the TNFR1 signalling complex, thereby preventing aberrant cell death. Both HOIL-1 and HOIP prevent embryonic lethality at mid-gestation by interfering with aberrant TNFR1-mediated endothelial cell death, which only partially depends on RIPK1 kinase activity. Co-deletion of caspase-8 with RIPK3 or MLKL prevents cell death in Hoil-1-/- (also known as Rbck1-/-) embryos, yet only the combined loss of caspase-8 with MLKL results in viable HOIL-1-deficient mice. Notably, triple-knockout Ripk3-/-Casp8-/-Hoil-1-/- embryos die at late gestation owing to haematopoietic defects that are rescued by co-deletion of RIPK1 but not MLKL. Collectively, these results demonstrate that both HOIP and HOIL-1 are essential LUBAC components and are required for embryogenesis by preventing aberrant cell death. Furthermore, they reveal that when LUBAC and caspase-8 are absent, RIPK3 prevents RIPK1 from inducing embryonic lethality by causing defects in fetal haematopoiesis.

Postmortem microfocus computed tomography for noninvasive autopsies: experience in >250 human fetuses.

BACKGROUND: Noninvasive imaging autopsy alternatives for fetuses weighing <500 grams are limited. Microfocus computed tomography has been reported as a viable option in small case series with the potential to avoid an invasive autopsy. Implementation of postmortem microfocus computed tomography in a large cohort as part of routine clinical service has yet been unreported, and realistic "autopsy prevention rates" are unknown. OBJECTIVE: This study aimed to describe the range of abnormalities detectable on fetal microfocus computed tomography in a clinical setting and additional findings identified on the antenatal ultrasound and to estimate the invasive autopsy avoidance rate (ie, cases in which imaging was sufficient to deem autopsy unnecessary). STUDY DESIGN: A prospective observational case series of all fetuses referred for microfocus computed tomography imaging at a single institution was conducted for 3 years (2016-2019). Imaging was reported by 2 pediatric radiologists before autopsy, with "decision to proceed" based on the specialist perinatal pathologists' judgment and parental consent. Agreement rates between microfocus computed tomography and antenatal ultrasound were evaluated, and where feasible, diagnostic accuracy for microfocus computed tomography was calculated using autopsy as a reference standard. RESULTS: A total of 268 fetuses were included (2-350 grams body weight; 11-24 weeks' gestation), with cause for demise in 122 of 268 (45.5%). Of the 122 fetuses, 64 (52.5%) exhibited fetal anomalies. Although 221 of 268 (82.5%) fetuses had consent for invasive autopsy, only 29 of the 221 (13.1%) underwent this procedure, which implied an autopsy avoidance rate of 192 of 221 (86.9%). Complete agreement was present for all brain, thoracic, and abdominal pathologies, whereas sensitivity and specificity for cardiac anomalies were 66.7% and 91.7%, respectively. Microfocus computed tomography and antenatal ultrasound agreement was found in 219 of 266 cases (81.9%), with partial agreement in 21 of 266 (7.9%) and disagreement in 26 of 266 (10.5%), mostly because of additional cardiac, soft tissue, or genitourinary findings by microfocus computed tomography, which were not seen on the ultrasound. CONCLUSION: Fetal microfocus computed tomography imaging is a viable and useful tool for imaging early gestational fetuses and can avoid the need for invasive autopsy. Confirmation of antenatal diagnoses is achieved in most cases, and additional anomalies may also be detected.

Chondroid and Osseous Metaplasia of the Central Fibrous Body in Adolescent Hearts with Mutations in TNNI3 and TNNT2 genes.

The histological spectrum of the central fibrous body (CFB) of the heart, particularly in humans, is not fully characterized. Herein, we describe the presence of cartilage and bone within the CFB of 2 explanted heart specimens from patients with known mutation-driven cardiomyopathy involving the TNNI3 and TNNT2 genes, review the existing literature on the identified variants particularly TNNI3 (p.Asn185Thrfs*14) and TNNT2 (p.Arg141Trp), and provide insights into the plausible nature of such histopathological observation based on animal studies and the few reported cases in humans.

Reappraising myocardial fibrosis in severe aortic stenosis: an invasive and non-invasive study in 133 patients.

Aims: To investigate myocardial fibrosis (MF) in a large series of severe aortic stenosis (AS) patients using invasive biopsy and non-invasive imaging. Methods and results: One hundred thirty-three patients with severe, symptomatic AS accepted for surgical aortic valve replacement underwent cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) and extracellular volume fraction (ECV) quantification. Intra-operative left ventricular (LV) biopsies were performed by needle or scalpel, yielding tissue with (n = 53) and without endocardium (n = 80), and compared with 10 controls. Myocardial fibrosis occurred in three patterns: (i) thickened endocardium with a fibrotic layer; (ii) microscopic scars, with a subendomyocardial predominance; and (iii) diffuse interstitial fibrosis. Collagen volume fraction (CVF) was elevated (P < 0.001) compared with controls, and higher (P < 0.001) in endocardium-containing samples with a decreasing CVF gradient from the subendocardium (P = 0.001). Late gadolinium enhancement correlated with CVF (P < 0.001) but not ECV. Both LGE and ECV correlated independently (P < 0.001) with N-terminal pro-brain natriuretic peptide and high-sensitivity-troponin T. High ECV was also associated with worse LV remodelling, left ventricular ejection fraction and functional capacity. Combining high ECV and LGE better identified patients with more adverse LV remodelling, blood biomarkers and histological parameters, and worse functional capacity than each parameter alone. Conclusion: Myocardial fibrosis in severe AS is complex, but three main patterns exist: endocardial fibrosis, microscars (mainly in the subendomyocardium), and diffuse interstitial fibrosis. Neither histological CVF nor the CMR parameters ECV and LGE capture fibrosis in its totality. A combined, multi-parametric approach with ECV and LGE allows best stratification of AS patients according to the response of the myocardial collagen matrix.

Interstitial Lung Disease in Children Made Easier Well, Almost.

Interstitial lung disease (ILD) in pediatric patients is different from that in adults, with a vast array of pathologic conditions unique to childhood, varied modes of presentation, and a different range of radiologic appearances. Although rare, childhood ILD (chILD) is associated with significant morbidity and mortality, most notably in conditions of disordered surfactant function, with respiratory failure in 100% of neonates with surfactant protein B dysfunction and 100% mortality without lung transplantation. The authors present a summary of lung development and anatomy, followed by an organized approach, using the structure and nomenclature of the 2013 update to the chILD Research Network classification system, to aid radiologic diagnosis of chILD. Index radiologic cases with contemporaneous histopathologic findings illustrate a summary of recent imaging studies covering the full spectrum of chILD. chILD is best grouped by age at presentation from infancy (diffuse developmental disorders, lung growth abnormalities, specific conditions of unknown origin, surfactant dysfunction mutations) to later childhood (disorders of the normal host, disorders related to systemic disease processes, disorders related to immunocompromise). Appreciation of the temporal division of chILD into infant and later childhood onset, along with a sound understanding of pulmonary organogenesis and surfactant homeostasis, will aid in providing useful insight into this important group of pediatric conditions. Application of secondary lobular anatomy to interpretation of thin-section computed tomographic images is pivotal to understanding patterns of ILD and will aid in selecting and narrowing a differential diagnosis. ©RSNA, 2017.

Multiple Cardiac Rhabdomyomas Visualised Using Micro-CT in a Case of Tuberous Sclerosis.

Cardiac rhabdomyoma is the most common tumour of the heart in infancy and childhood, representing approximately 60% of all primary cardiac tumours in these age groups. Though they have a tendency to regress with advancing age and are histologically benign, rhabdomyomas may cause mechanical obstruction to blood flow, arrhythmia, congestive cardiac failure and death and may be associated with underlying genetic syndromes such as tuberous sclerosis. We present the case of a primigravida in her early 20s with no significant medical history who was referred to the Fetal Medicine Unit at 34 weeks' gestation following the detection of an irregular fetal heartbeat. An anomaly scan at 20 weeks had been reported as normal.

Postmortem cardiovascular magnetic resonance imaging in fetuses and children: a masked comparison study with conventional autopsy.

BACKGROUND: Perinatal and pediatric autopsies have declined worldwide in the past decade. We compared the diagnostic accuracy of postmortem, cardiovascular magnetic resonance (CMR) imaging with conventional autopsy and histopathology assessment in fetuses and children. METHODS AND RESULTS: We performed postmortem magnetic resonance imaging in 400 fetuses and children, using a 1.5-T Siemens Avanto magnetic resonance scanner before conventional autopsy. A pediatric CMR imager reported the CMR images, masked to autopsy information. The pathologists were masked to the information from CMR images. The institutional research ethics committee approved the study, and parental consent was obtained. Assuming a diagnostic accuracy of 50%, 400 cases were required for a 5% precision of estimate. Three cases were excluded from analysis, 2 with no conventional autopsy performed and 1 with insufficient CMR sequences performed. Thirty-eight CMR data sets were nondiagnostic (37 in fetuses ≤24 weeks; 1 in a fetus >24 weeks). In the remaining 359 cases, 44 cardiac abnormalities were noted at autopsy. Overall sensitivity and specificity (95% confidence interval) of CMR was 72.7% (58.2-83.7%) and 96.2% (93.5-97.8%) for detecting any cardiac pathology, with positive and negative predictive values of 72.7% (58.2-83.7%) and 96.2% (93.5-97.8%), respectively. Higher sensitivity of 92.6% (76.6-97.9%), specificity of 99.1% (97.4-99.7%), positive predictive value of 89.3% (72.8-96.3%), and negative predictive value of 99.4% (97.8-99.8%) were seen for major structural heart disease. CONCLUSIONS: Postmortem CMR imaging may be a useful alternative to conventional cardiac autopsy in fetuses and children for detecting cardiac abnormalities. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01417962.

Reference ranges for organ weights of infants at autopsy: results of >1,000 consecutive cases from a single centre.

BACKGROUND: Infancy is the most common period for childhood death, including both neonatal deaths from obstetric or medical complications and sudden unexpected infant deaths. The weighing of organs at autopsy is an established process and is recommended in current protocols. However, minimal contemporary data is available regarding reference ranges for organ weights of infants. METHODS: Organ weight data for consecutive infant autopsies over a 14 year period performed at a single tertiary centre, including >1,000 cases, were examined in order to provide up to date reference ranges across this age range, using linear regression modelling and the standard LMS method. RESULTS: 1,525 infant autopsies were analysed, of which 1,190 were subsequently used in the creation of linear regression models prior to performance of the LMS method. Organ weight charts were produced for the 5th, 25th, 50th, 75th and 95th centiles for the heart, lungs, liver, spleen, kidneys, pancreas, thymus gland and adrenal glands. CONCLUSION: This study provides the largest single centre contemporary dataset of infant autopsies allowing provision of up-to-date 'normal' ranges for all major organ weights across this age range.

Immersion-related deaths in infants and children: autopsy experience from a specialist center.

PURPOSE: To investigate the demographics, circumstances and autopsy findings in infants and children dying following immersion. METHODS: A retrospective review of a pediatric autopsy database at a specialist center over a 16-year period (1995-2010) was undertaken to identify deaths between 7 days and 16 years of age in whom death occurred following immersion. RESULTS: 28 infants and children died following immersion during the study period. 82 % were aged <4 years, with peak age of death between 1 and 2 years. Immersion occurred at home in a bath or private pool in 70 % of cases. There was a lack of direct supervision in all but two cases where the information was recorded (91 %); one of these cases occurred in a public swimming lesson, and in the other the carer was incapacitated. Autopsy findings were non-specific. Facial or subconjunctival petechial hemorrhages were a feature of 18 % of cases. There was increased lung weight, or histological pulmonary edema/intra-alveolar hemorrhage in all but one case. CONCLUSIONS: The data suggest that the majority of pediatric immersion-related deaths were potentially preventable with appropriate supervision. The findings strongly support the role of education regarding adequate carer supervision of infants and children while bathing, particularly in children with underlying conditions such as epilepsy. As private pools and "hot tubs" become more common in the UK and other jurisdictions, specific recommendations such as fencing pools will need to be included in advice to carers. So-called 'dry drowning" appears to be an uncommon mechanism of death in this age group.

Sudden unexpected infant deaths associated with car seats.

The purpose of this study was to investigate the frequency, circumstances, demographics, and causes of death of infants dying while seated in car safety seats. A retrospective review of a pediatric autopsy database at a specialist center over a 16-year period was undertaken to identify any infant deaths (aged <1 year), in whom death occurred while seated in a car safety seat. Fourteen car seat-associated deaths were identified from a total of 1,465 coronial infant autopsies (0.96 %). Four involved infants were being appropriately transported in the car seat, all of whom had a medical underlying cause of death (one infection and three congenital heart disease). The majority (10 cases; 70 %) occurred while car seats were being inappropriately used, outside of the car, including as an alternative to a cot or high-chair. Five of these infants died of explained causes, but four deaths remained unexplained after autopsy, and in one no cause of death was available. There were no cases of previously healthy infants dying unexpectedly in a car seat when it was being used appropriately, and in this series there were no cases of traumatic death associated with car seats, either during road traffic accidents, or from falling or being suspended from a car seat. Infant deaths in car seats are rare. These data support the recommendation that car seats be used only for transport and not as alternatives for cots or high-chairs. More research is required to investigate the effect of travel in car seats on infants with underlying conditions. There appears to be no increased risk of unexpected deaths of healthy infants transported appropriately in car seats.

Measurement of myocardial extracellular volume fraction by using equilibrium contrast-enhanced CT: validation against histologic findings.

PURPOSE: To develop and validate equilibrium contrast material-enhanced computed tomography (CT) to measure myocardial extracellular volume (ECV) fraction by using a histologic reference standard and to compare equilibrium CT with equilibrium contrast-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: A local ethics committee approved the study, and all subjects gave fully informed written consent. An equilibrium CT protocol was developed using iohexol at 300 mg of iodine per milliliter (bolus of 1 mg per kilogram of body weight administered at a rate of 3 mL/sec, followed immediately by an infusion of 1.88 mL/kg per hour with CT imaging before and at 25 minutes after injection of bolus of contrast agent) and ECV within the myocardial septum measured using both equilibrium CT and equilibrium MR imaging in patients with severe aortic stenosis. Biopsy samples of the myocardial septum collected during valve replacement surgery were used for histologic quantification of extracellular fibrosis with picrosirius red staining. Equilibrium CT- and equilibrium MR imaging-derived ECV measurements were compared with histologically quantified fibrosis by using Pearson correlation. Agreement between equilibrium CT and equilibrium MR imaging was assessed by using Bland-Altman comparison. RESULTS: Twenty-three patients (16 male, seven female; mean age, 70.8 years; standard deviation, 8.3) were recruited. The mean percentage of histologic fibrosis was 18% (intersubject range, 5%-40%). There was a significant correlation between both equilibrium CT- and equilibrium MR imaging-derived ECV and percentage of histologic fibrosis (r = 0.71 [P < .001] and r = 0.84 [P < .0001], respectively). Equilibrium CT-derived ECV was significantly correlated to equilibrium MR imaging-derived ECV (r = 0.73). CONCLUSION: ECV measured by using equilibrium CT in patients with aortic stenosis correlates with histologic quantification of myocardial fibrosis and with ECV derived by using equilibrium MR imaging.

Autopsy findings of co-sleeping-associated sudden unexpected deaths in infancy: relationship between pathological features and asphyxial mode of death.

AIM: Co-sleeping is associated with increased risk of sudden unexpected death in infancy (SUDI)/sudden infant death syndrome (SIDS). The aim of this study is to examine autopsy findings from a single U.K. specialist centre to determine the relationship between co-sleeping and cause of death. METHODS: Retrospective analysis of >1500 paediatric autopsies carried out by paediatric pathologists over a 10-year period. SUDI was defined as sudden unexpected death of an infant aged 7-365 days; deaths were categorised into explained SUDI (cause of death was determined) and unexplained SUDI (equivalent to SIDS). RESULTS: There were 546 SUDI; sleeping arrangements were specifically recorded in 314; of these, 174 (55%) were co-sleeping-associated deaths. Almost two thirds (59%) of unexplained SUDI were co-sleeping compared to 44% explained SUDI (95% confidence interval (CI) 1.0-27.2%, P=0.03); however, this difference remained statistically significant only for the first 5 months of life (95% CI 3.5-33.2%, P=0.01). In unexplained SUDI aged < 6 months, there were no significant differences between co-sleeping and non-co-sleeping deaths with respect to ante-mortem symptoms, intrathoracic petechiae, macroscopic lung appearances, pulmonary haemosiderin-laden macrophages, and isolation of specific bacterial pathogens; however, fresh intra-alveolar haemorrhage was reported more commonly in co-sleeping (54%) than in those that were not (38%; 95% CI 1.4-30.5%, P=0.03). CONCLUSIONS: Co-sleeping is associated with unexplained SUDI/SIDS in infants aged < 6 months, suggesting that co-sleeping is related to the pathogenesis of death in younger infants. The finding that intra-alveolar haemorrhage is more common in co-sleeping suggests that a minority of co-sleeping-associated deaths may be related to an asphyxial process.

Clinicopathological features of fatal cardiomyopathy in childhood: an autopsy series.

AIM: Cardiomyopathy, a group of primary myocardial disorders, is an uncommon, but important, cause of death in childhood. This study examines the demographic, clinical and pathological features of fatal cardiomyopathy in childhood with particular reference to its classification and autopsy findings. METHOD: The method of this study was a retrospective structured review of all paediatric autopsies performed at a single specialist centre from 1995 to 2009 inclusive, in order to determine the demographic, clinical and pathological features of fatal cardiomyopathy. RESULTS: From a total of 2229 autopsies performed at the centre during the study period on live-born infants and children, 34 confirmed cases of cardiomyopathy were identified (1.5%). More than half (59%) of these cases occurred in infants (less than 1 year of age). Heart weight of cardiomyopathy cases was significantly greater than those with normal hearts (P < 0.001), and 77% had heart weights above the 95th percentile of the normal expected range for age, including all of those over 1 year age. Of cardiomyopathy cases, 50% were primary dilated cardiomyopathy and 27% were primary hypertrophic cardiomyopathy. Twelve of 34 cases (35%) presented as sudden unexpected death, the diagnosis of cardiomyopathy being only made at autopsy. CONCLUSION: Cardiomyopathy is an uncommon cause of death in infancy and childhood. It can present as sudden unexpected death and encompasses a range of aetiologies. Heart weight above the 95th percentile at autopsy is present in most cases but heart weight may be within the normal range in infants.

Postmortem tandem mass spectrometry profiling for detection of infection in unexpected infant death.

Numerous hypotheses have been suggested to explain the cause of sudden unexpected infant death, including infection. As part of the autopsy, routine ancillary investigations are performed, including blood/bile tandem mass spectrometry (TMS) primarily for detection of metabolic disease. The aim of this study was to evaluate and assess TMS derived acylcarnitine profiles to determine whether infectious deaths were associated with characteristic profiles. As part of a retrospective study including >2,500 pediatric autopsies at a single specialist centre over a 14 year period, acylcarnitine profiles were reviewed. Using multiple linear regression, standardised residuals were prepared and findings compared between different cause of death groups, including unexplained, focal infection, microbiological infection and accidental injuries. 415 blood samples from SUDI autopsies were identified. Statistically significant differences in TMS profiles were identified between those dying of infection and the unexplained SUDI group, including changes in free carnitine, short chain acylcarnitines and octanoylcarnitine. Cases with microbiological infection diagnosed only from postmortem cultures did not show any significant difference from the unexplained group. Postmortem TMS profiling identifies SUDI deaths which are associated with histological evidence of infection, and an acylcarnitine profile suggesting perturbation of oxidative metabolism. Such findings raise the possibility that more comprehensive TMS profiling may offer additional diagnostic clues beyond screening for metabolic disorders, and may contribute to determination of mode of death.

Equilibrium contrast cardiovascular magnetic resonance for the measurement of diffuse myocardial fibrosis: preliminary validation in humans.

BACKGROUND: Diffuse myocardial fibrosis is a final end point in most cardiac diseases. It is missed by the cardiovascular magnetic resonance (CMR) late gadolinium enhancement technique. Currently, quantifying diffuse myocardial fibrosis requires invasive biopsy, with inherent risk and sampling error. We have developed a robust and noninvasive technique, equilibrium contrast CMR (EQ-CMR) to quantify diffuse fibrosis and have validated it against the current gold standard of surgical myocardial biopsy. METHODS AND RESULTS: The 3 principles of EQ-CMR are a bolus of extracellular gadolinium contrast followed by continuous infusion to achieve equilibrium; a blood sample to measure blood volume of distribution (1-hematocrit); and CMR to measure pre- and postequilibrium T1 (with heart rate correction). The myocardial volume of distribution is calculated, reflecting diffuse myocardial fibrosis. Clinical validation occurred in patients undergoing aortic valve replacement for aortic stenosis or myectomy in hypertrophic cardiomyopathy (n=18 and n=8, respectively). Surgical biopsies were analyzed for picrosirius red fibrosis quantification on histology. The mean histological fibrosis was 20.5+/-11% in aortic stenosis and 17.1+/-7.4% in hypertrophic cardiomyopathy. EQ-CMR correlated strongly with biopsy histological fibrosis: aortic stenosis, r(2)=0.86, Kendall Tau coefficient (T)=0.71, P<0.001; hypertrophic cardiomyopathy, r(2)=0.62, T=0.52, P=0.08; combined r(2)=0.80, T=0.67, P<0.001. CONCLUSIONS: We have developed and validated a new technique, EQ-CMR, to measure diffuse myocardial fibrosis as an add-on to a standard CMR scan, which allows for the noninvasive quantification of the diffuse fibrosis burden in myocardial diseases.

Pleuroparenchymal fibroelastosis in patients with pulmonary disease secondary to bone marrow transplantation.

This study presents four patients who underwent bone marrow transplantation and subsequently developed pleuroparenchymal fibroelastosis, hitherto reported as an idiopathic condition. All presented clinically with pneumothorax and subpleural fibrosis on high-resolution computed tomography. In addition to the expected obliterative bronchiolitis, histopathology showed coexistent subpleural changes, and the relationship of pathology in multiple anatomic compartments in post bone marrow transplantation pulmonary disease is discussed.

Micro-CT Imaging of Pediatric Thyroglossal Duct Cysts: A Prospective Case Series.

Objectives: To determine the feasibility of micro-CT as a high-resolution 3D imaging tool for thyroglossal duct cysts and to evaluate its role augmenting traditional histopathological examination of resected specimens. Methods: A single centre, prospective case series of consecutive children undergoing excision of a thyroglossal duct cyst was performed at a quaternary paediatric referral hospital in the United Kingdom. Consecutive children listed for excision of a thyroglossal duct cyst whose parents agreed to participate were included and there were no exclusion criteria. Results: Surgically excised thyroglossal duct cyst or remnant specimens from five patients (two males, three females) were examined using micro-CT alongside traditional histopathological examination. In all cases, micro-CT imaging was able to demonstrate 3D imaging datasets of the specimens successfully and direct radio-pathological comparisons were made (Figures 1-5, Supplementary Video 1). Conclusions: The study has shown the feasibility and utility of post-operative micro-CT imaging of thyroglossal duct cysts specimens as a visual aid to traditional histopathological examination. It better informs the pathological specimen sectioning using multi-planar reconstruction and volume rendering tools without tissue destruction. In the complex, often arborised relationship between a thyroglossal duct cyst and the hyoid, micro-CT provides valuable image plane orientation and indicates proximity of the duct to the surgical margins. This is the first case series to explore the use of micro-CT imaging for pediatric thyroglossal duct specimens and it informs future work investigating the generalizability of micro-CT imaging methods for other lesions, particularly those from the head and neck region where precisely defining margins of excision may be challenging.

Preclinical Optimization and Safety Studies of a New Lentiviral Gene Therapy for p47phox-Deficient Chronic Granulomatous Disease.

Chronic granulomatous disease (CGD) is an inherited blood disorder of phagocytic cells that renders patients susceptible to infections and inflammation. A recent clinical trial of lentiviral gene therapy for the most frequent form of CGD, X-linked, has demonstrated stable correction over time, with no adverse events related to the gene therapy procedure. We have recently developed a parallel lentiviral vector for p47phox-deficient CGD (p47phoxCGD), the second most common form of this disease. Using this vector, we have observed biochemical correction of CGD in a mouse model of the disease. In preparation for clinical trial approval, we have performed standardized preclinical studies following Good Laboratory Practice (GLP) principles, to assess the safety of the gene therapy procedure. We report no evidence of adverse events, including mutagenesis and tumorigenesis, in human hematopoietic stem cells transduced with the lentiviral vector. Biodistribution studies of transduced human CD34+ cells indicate that the homing properties or engraftment ability of the stem cells is not negatively affected. CD34+ cells derived from a p47phoxCGD patient were subjected to an optimized transduction protocol and transplanted into immunocompromised mice. After the procedure, patient-derived neutrophils resumed their function, suggesting that gene correction was successful. These studies pave the way to a first-in-man clinical trial of lentiviral gene therapy for the treatment of p47phoxCGD.

Filamin A (FLNA) mutation-A newcomer to the childhood interstitial lung disease (ChILD) classification.

AIM: Interstitial lung disease (ILD) in infants represents a rare and heterogenous group of disorders, distinct from those occurring in adults. In recent years a new entity within this category is being recognized, namely filamin A (FLNA) mutation related lung disease. Our aims are to describe the clinical and radiological course of patients with this disease entity to aid clinicians in the prognostic counseling and management of similar patients they may encounter. METHOD: A retrospective case note review was conducted of all patients treated at our institution (a specialist tertiary referral childrens' center) for genetically confirmed FLNA mutation related lung disease. The clinical presentation, evolution, management and radiological features were recorded and a medical literature review of Medline indexed articles was conducted. RESULTS: We present a case series of four patients with interstitial lung disease and genetically confirmed abnormalities within the FLNA gene. Their imaging findings all reveal a pattern of predominantly upper lobe overinflation, coarse pulmonary lobular septal thickening and diffuse patchy atelectasis. The clinical outcomes of our patients have been variable ranging from infant death, lobar resection and need for supplemental oxygen and bronchodilators. CONCLUSION: The progressive nature of the pulmonary aspect of this disorder and need for early aggressive supportive treatment make identification crucial to patient management and prognostic counseling.