Human JAK1 gain of function causes dysregulated myelopoeisis and severe allergic inflammation.

Primary atopic disorders are a group of inborn errors of immunity that skew the immune system toward severe allergic disease. Defining the biology underlying these extreme monogenic phenotypes reveals shared mechanisms underlying common polygenic allergic disease and identifies potential drug targets. Germline gain-of-function (GOF) variants in JAK1 are a cause of severe atopy and eosinophilia. Modeling the JAK1GOF (p.A634D) variant in both zebrafish and human induced pluripotent stem cells (iPSCs) revealed enhanced myelopoiesis. RNA-Seq of JAK1GOF human whole blood, iPSCs, and transgenic zebrafish revealed a shared core set of dysregulated genes involved in IL-4, IL-13, and IFN signaling. Immunophenotypic and transcriptomic analysis of patients carrying a JAK1GOF variant revealed marked Th cell skewing. Moreover, long-term ruxolitinib treatment of 2 children carrying the JAK1GOF (p.A634D) variant remarkably improved their growth, eosinophilia, and clinical features of allergic inflammation. This work highlights the role of JAK1 signaling in atopic immune dysregulation and the clinical impact of JAK1/2 inhibition in treating eosinophilic and allergic disease.

Biliary Atresia in 2021: Epidemiology, Screening and Public Policy.

Biliary atresia (BA) is a rare newborn liver disease with significant morbidity and mortality, especially if not recognized and treated early in life. It is the most common cause of liver-related death in children and the leading indication for liver transplantation in the pediatric population. Timely intervention with a Kasai portoenterostomy (KPE) can significantly improve prognosis. Delayed disease recognition, late patient referral, and untimely surgery remains a worldwide problem. This article will focus on biliary atresia from a global public health perspective, including disease epidemiology, current national screening programs, and their impact on outcome, as well as new and novel BA screening initiatives. Policy challenges for the implementation of BA screening programs will also be discussed, highlighting examples from the North American, European, and Asian experience.

Cholangitis Definition and Treatment after Kasai Hepatoportoenterostomy for Biliary Atresia: A Delphi Process and International Expert Panel.

(1) Background: Acute cholangitis during the first year after Kasai hepatoportoenterostomy (HPE) has a negative impact on patient and native liver survival. There are no consistent guidelines for the definition, treatment, and prophylaxis of cholangitis after HPE. The aim of this study was to develop definition, treatment, and prophylaxis guidelines to allow for expeditious management and for standardization in reporting. (2) Methods: the Delphi method, an extensive literature review, iterative rounds of surveys, and expert panel discussions were used to establish definition, treatment, and prophylaxis guidelines for cholangitis in the first year after HPE. (3) Results: Eight elements (pooled into two groups: clinical and laboratory/imaging) were identified to define cholangitis after HPE. The final proposed definitions for suspected and confirmed cholangitis are a combination of one element, respectively, two elements from each group; furthermore, the finding of a positive blood culture was added to the definition of confirmed cholangitis. The durations for prophylaxis and treatment of suspected and confirmed cholangitis were uniformly agreed upon by the experts. (4) Conclusions: for the first time, an international consensus was found for guidelines for definition, treatment, and prophylaxis for cholangitis during the first year after Kasai HPE. Applicability will need further prospective multicentered studies.

The effects of child anxiety and depression on concordance between parent-proxy and self-reported health-related quality of life for pediatric liver transplant patients.

BACKGROUND: HRQOL is a key outcome following pediatric LT. Parent-proxy reports may substitute for patients unable to report their own HRQOL. This study compared parent-proxy and self-reported HRQOL in children who have undergone LT. METHODS: Pediatric LT recipients between the ages of 8 and 18 years, and a parent, completed self and proxy versions of the PeLTQL questionnaire, PedsQL Generic and Transplant modules, and standardized measures of depression and anxiety. RESULTS: Data from 129 parent-patient dyads were included. Median parent age was 44 years, and most (89%) were mothers. Median patient age was 2.5 years at LT and 13.6 years at the time of study participation. Parents had significantly lower scores than patients on PedsQL total generic (70.8 ± 18.5 and 74.3 ± 19.0, p = .01), PeLTQL coping and adjustment (63.0 ± 15.6 and 67.3 ± 16.2, p < .01), and social-emotional (66.3 ± 14.9 and 71.9 ± 15.6, p < .001) domains. Higher patient anxiety and depression were related to larger absolute differences between parent-proxy and self-reported scores on all HRQOL measures (all p < .05). In this disparity, parents reported higher HRQOL scores than their child as self-reported anxiety and depression scores increased. CONCLUSIONS: Differences in concordance between parent-proxy and self-reported HRQOL scores can be more prominent when children have more symptoms of anxiety and depression. Children's mental health symptoms should be queried, if feasible, when interpreting differences in parent and child reports of HRQOL.

Sequential paternal haploidentical donor liver and HSCT in EPP allow discontinuation of immunosuppression post-organ transplant.

BACKGROUND: EPP is characterized by photosensitivity and by liver disease. When LT is performed in EPP, recurrence often occurs in the allograft due to ongoing protoporphyrin production in bone marrow. Therefore, curative treatment requires allogeneic HSCT after LT. Long-term immunosuppression could be spared by using the same donor for both transplants. METHODS: A 2-year-old girl with EPP in liver failure underwent liver transplant from her father. Transfusion and apheresis therapy were used to lower protoporphyrin levels before and after liver transplant. Ten weeks after liver transplant, she underwent HSCT, using the same donor. Conditioning was with treosulfan, fludarabine, cyclophosphamide, and ATG. GVHD prophylaxis was with abatacept, methotrexate, MMF, and tacrolimus. We followed the patient's erythrocyte protoporphyrin and liver and skin health for 2 years after transplant. RESULTS: After hematopoietic stem cell engraftment, a decline in protoporphyrin levels was observed, with clinical resolution of photosensitivity. Liver biopsies showed no evidence of EPP. Mild ACR occurred and responded to steroid pulse. Two years post-HSCT, the patient has been weaned off all immunosuppression and remains GVHD and liver rejection free. CONCLUSIONS: Sequential liver and HSCT from the same haploidentical donor are feasible in EPP. This strategy can allow for discontinuation of immune suppression.

Post-traumatic stress as a determinant of quality of life in pediatric solid-organ transplant recipients.

Living with end-stage organ failure is associated with an accumulation of traumatic medical events, and despite recovery after solid-organ transplantation (SOT), many children continue to exhibit lower quality of life (QOL). Few studies have examined the relationship between post-traumatic stress disorder (PTSD) and QOL among pediatric SOT recipients. We conducted a retrospective, cross-sectional review of 61 pediatric SOT recipients (12 heart, 30 kidney, and 19 liver) to evaluate the association of PTSD with self-reported QOL. PTSD was measured by the Child Trauma Screening Questionnaire (CTSQ), and QOL was measured using the PedsQL and PedsQL Transplant Module (PedsQL-TM) surveys. Demographics, baseline, and contemporaneous factors were tested for independent association. SOT recipients were 15.2 (12.1-17.6) years old at survey completion. Median CTSQ score was 2 (1-3), highest in kidney recipients, and 13% were identified as high risk for PTSD. Median PedsQL score was 83 (70-91) and significantly associated with the CTSQ score (r = -.68, p < .001). Median PedsQL Transplant Module score was 89 (83-95) and similarly associated with the CTSQ score (r = -.64, p < .001). Age at time of surveys and presence of any disability were also independently associated with PedsQL and PedsQL-TM, respectively. When adjusted for Emotional Functioning, CTSQ remained associated with PedsQL subscores (r = -.65, p < .001). Trauma symptoms are a major modifiable risk factor for lower self-perceived QOL and represent a potentially important target for post-transplant rehabilitation. Additional research is needed to understand the root contributors to PTSD and potential treatments in this population.

Idiopathic splenomegaly in childhood and the spectrum of RAS-associated lymphoproliferative disease: a case report.

BACKGROUND: KRAS (KRAS proto-oncogene, GTPase; OMIM: 190,070) encodes one of three small guanosine triphosphatase proteins belonging to the RAS family. This group of proteins is responsible for cell proliferation, differentiation and inhibition of apoptosis. Gain-of-function variants in KRAS are commonly found in human cancers. Non-malignant somatic KRAS variants underlie a subset of RAS-associated autoimmune leukoproliferative disorders (RALD). RALD is characterized by splenomegaly, persistent monocytosis, hypergammaglobulinemia and cytopenia, but can also include autoimmune features and lymphadenopathy. In this report, we describe a non-malignant somatic variant in KRAS with prominent clinical features of massive splenomegaly, thrombocytopenia and lymphopenia. CASE PRESENTATION: A now-11-year-old girl presented in early childhood with easy bruising and bleeding, but had an otherwise unremarkable medical history. After consulting for the first time at 5 years of age, she was discovered to have massive splenomegaly. Clinical follow-up revealed thrombocytopenia, lymphopenia and increased polyclonal immunoglobulins and C-reactive protein. The patient had an unremarkable bone marrow biopsy, flow cytometry showed no indication of expanded double negative T-cells, while malignancy and storage disorders were also excluded. When the patient was 8 years old, whole exome sequencing performed on DNA derived from whole blood revealed a heterozygous gain-of-function variant in KRAS (NM_004985.5:c.37G > T; (p.G13C)). The variant was absent from DNA derived from a buccal swab and was thus determined to be somatic. CONCLUSIONS: This case of idiopathic splenomegaly in childhood due to a somatic variant in KRAS expands our understanding of the clinical spectrum of RAS-associated autoimmune leukoproliferative disorder and emphasizes the value of securing a molecular diagnosis in children with unusual early-onset presentations with a suspected monogenic origin.

Role of transient elastography and APRI in the assessment of pediatric cystic fibrosis liver disease.

Background: Diagnosis and monitoring of cystic fibrosis liver disease (CFLD) is challenging. Transient elastography (TE) is a rapid, non-invasive method for assessing liver fibrosis. Its role in detecting fibrosis in CFLD has only begun to be explored. The aspartate aminotransferase to platelet ratio index (APRI) has been validated as a predictor of hepatic fibrosis in other chronic liver diseases. The purpose of this study was to assess the utility of APRI and TE in identifying liver fibrosis in pediatric CF patients. Methods: Patients aged 2-18 years were recruited from the British Columbia Children's Hospital CF clinic. Patients were determined to have CFLD using standard criteria. Charts were reviewed, and each patient underwent TE. Results: Of the 55 patients included in the study (50.9% male, mean age 11.6 y), 22 (40%) had CFLD. All mean liver enzymes were higher in the CFLD group, notably alanine transaminase (p = 0.031). Mean liver stiffness (LS) and APRI were also higher in the CFLD group (LS: 5.9 versus 4.5 kPa, p = 0.015; APRI: 0.40 versus 0.32, p = 0.119). Linear regression showed a mild positive association between the two (r 2 = 0.386). Conclusions: TE values were higher among CFLD patients and correlated with APRI values, suggesting that these tools may have clinical applications for identifying and following this population. Further research is needed on a larger scale to determine the relative value and clinical utility of TE and APRI among patients with CFLD.

Fontan-Associated Liver Disease: Spectrum of Disease in Children and Adolescents.

Background Information is evolving on liver disease in pediatric patients with Fontan physiology. The purpose of this investigation is to evaluate the spectrum of liver disease in a pediatric population of patients with Fontan physiology and evaluate transient elastography (TE) as a noninvasive marker of liver disease. Methods and Results We prospectively enrolled all children with Fontan physiology. All patients underwent comprehensive liver evaluation including liver enzymes (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase), aspartate transaminase to platelet ratio index, albumin, bilirubin, international normalized ratio, complete blood cell count, abdominal ultrasound, and TE. Transjugular liver biopsies and hemodynamic measurements were performed in a subset of patients. A total of 76 children (median, 11.7; interquartile range, 8.4-14.8 [56% male]) were evaluated, with 17 having a transjugular liver biopsy (median 14.8 years; interquartile range, 14.3-17.4). All biopsies showed pathological changes. The severity of liver pathology did not correlate with TE. There was a positive correlation between TE and time since Fontan (R=0.42, P<0.01), aspartate transaminase to platelet ratio index (R=0.29, P=0.02), aspartate transaminase (R=-0.42, P<0.01), and platelets (R=-0.42, P<0.01). Splenomegaly on abdominal ultrasound was correlated with TE (z=-2.2, P=0.03), low platelet count (z=1.9, P=0.05), low aspartate transaminase (z=1.9, P=0.02), and low alkaline phosphatase (z=2.4, P=0.02). Conclusions Liver disease was ubiquitous in our cohort of pediatric patients with Fontan Physiology. Given the correlation between TE and time from Fontan, TE shows potential as a prospective marker of liver pathology. However, individual measurements with TE do not correlate with the severity of pathology. Given the prevalence of liver disease in this population, protective measures of liver health as well as routine liver health surveillance should be implemented with consideration for hepatology consultation and biopsy in the event of abnormal liver biochemical markers or imaging.

Stability of hepatitis B viral load during pregnancy and implications for antepartum prophylaxis: A prospective cohort study.

BACKGROUND: We examined changes in hepatitis B virus (HBV) viral loads (VLs) in pregnancy, their association with hepatitis B e antigen (HBeAg), and the associated infant outcomes. METHODS: We prospectively followed 132 mothers positive for hepatitis B surface antigen (HBsAg) and their 135 infants from 2011 to 2015 in Vancouver, British Columbia. Outcome measures included association between maternal HBeAg and high (>200,000 IU/mL) or low (≤200,000 IU/mL) HBV VL, changes in HBV VL through pregnancy, infant HBsAg status, and infant completion of the HBV vaccination series. RESULTS: f the 91 participants with an available HBV VL, 13 (14.3%) had an HBV VL of more than 200,000 IU/mL. Of 59 participants with paired HBeAg and HBV VL in pregnancy, 6 had an HBV VL of more than 200,000 IU/mL; of interest, 2 of the 6 (33.3%) were HBeAg-negative. Thirty-eight participants had HBV VL results at both mid-trimester and delivery. For these 38 participants, Wilcoxon signed-ranks test for paired data found that an HBV VL remained stable (p = .58). We observed no perinatal transmissions. However, 20.7% of infants did not have a documented complete HBV vaccination series, 20.0% did not have post-vaccination HBsAg testing completed, and 18% did not have anti-HBs titres measured by age 12 months. CONCLUSIONS: Our study demonstrates that HBeAg and HBV VL are not reliably predictive of each other. This supports the improved predictive value of VL measurement in pregnancy to risk stratify pregnant patients to offer antiviral treatment when indicated and further minimize the risk of perinatal transmission.

Province-wide Biliary Atresia Home Screening Program in British Columbia: Evaluation of First 2 Years.

BACKGROUND AND OBJECTIVES: Biliary atresia (BA), a rare newborn liver disease, is the leading cause of liver-related death in children. Early disease recognition and timely surgical Kasai hepatoportoenterostomy (KP) offers long-term survival without liver transplant. Universal BA screening in Taiwan using infant stool color cards (ISCCs) has proven effectiveness. We report our experience with infant stool color card (ISCC) BA screening in a province-wide program in British Columbia (BC). The objective of this study is to assess program performance and cost from launch April 1, 2014 to March 31, 2016. METHODS: ISCCs distributed to families upon maternity ward discharge. Parents were instructed to monitor their infant's stool color for 1 month and contacted the screening center with concerns. The number of live births, ISCC distribution, BA cases, and costs were recorded. Cases with Program screen success had both acholic stool recognition (ISCC screen success) and timely referral for BA. RESULTS: All 126 maternity units received ISCCs. Of 87,583 live births there were 6 BA cases. Of the 5 cases with ISCC Screen Success 3 had Program Screen Success. The median KP age in the program screen success and failure groups was 49 (42-52) and 116 (49-184) days, respectively. Program sensitivity was 50%, specificity 99%, positive predictive value 4%, and negative predictive value 99%. A random sample of 1054 charts at BC Children's Hospital found an ISCC distribution rate of 94%. After a phase-in period, the annual program cost was $30,033.82, and the ISCC cost per birth was $0.68. CONCLUSIONS: The screening program has high specificity and distribution with low cost. Successful program case identification had earlier age at KP. Program modifications aim to improve sensitivity. Longer-term studies will determine program impact on health outcomes.

Antenatal Treatment with Intravenous Immunoglobulin to Prevent Gestational Alloimmune Liver Disease: Comparative Effectiveness of 14-Week versus 18-Week Initiation.

BACKGROUND: Antenatal therapy with high-dose intravenous immunoglobulin (IVIG) may prevent gestational alloimmune liver disease (GALD). OBJECTIVE: The objective of this study was to determine the effectiveness of this approach in a large cohort of women at risk for poor pregnancy outcome due to GALD. METHODS: Women with a history of affected offspring were provided antenatal IVIG treatment and data were acquired prospectively from 1997 to 2015. The outcomes of treated pregnancies were compared to those of untreated pregnancies, and the effectiveness of starting at 14 weeks was compared to that of starting at 18 weeks. RESULTS: A total of 188 treated pregnancies in 151 women were analyzed. Only 30% (n = 105) of untreated gestations resulted in healthy offspring as compared to 94% (n = 177) of treated pregnancies (p < 0.0001). Treated gestations of both the 14-week (n = 108) and the 18-week (n = 80) start cohort showed a decreased rate of fetal loss relative to untreated gestations (p < 0.0001). Equivalent outcomes were recorded in the 18-week versus the 14-week start cohort (p > 0.05). Few adverse events or complications of antenatal therapy were recorded. CONCLUSION: Antenatal therapy with high-dose IVIG initiated at either 18 or 14 gestational weeks effectively prevents poor outcome of pregnancies at risk for GALD.

Clinical Characteristics and Complications of Pediatric Liver Biopsy: A Single Centre Experience.

INTRODUCTION: Percutaneous liver biopsy (LB) is the gold standard method for evaluation and management of patients with liver disease. The purpose of this study was to characterize pediatric patients undergoing LB at British Columbia Children's Hospital, and to determine the rate and timing of complications following the procedure. MATERIAL AND METHODS: The medical records of all pediatric patients who underwent LB during a six-year retrospective study were reviewed to collect demographic and procedure-related data. RESULTS: 223 LBs were performed, and 179 of these biopsies were percutaneous or transjugular. Elevated liver enzymes and cholestasis together accounted for almost 70% of the indications for LB, and the histological analysis of liver tissue yielded a specific diagnosis in 89 % of the cases. There were no deaths and no major complications related to LB. The most frequent minor complication was pain (59% of LBs) and the other complications were bleeding-related and classified as minor. The vast majority of complications (88%) were recognized within 8 h of the LB. CONCLUSIONS: LB is a valuable and safe procedure in pediatric patients with a low rate of complications. Pediatric patients can be discharged home safely should no complications occur within the first 8-12 h after the procedure.

Management of Pediatric Nonalcoholic Fatty Liver Disease by Academic Hepatologists in Canada: A Nationwide Survey.

BACKGROUND: The literature on the optimal clinical management of pediatric patients with nonalcoholic fatty liver disease (NAFLD) is limited. The objective of this study was to identify discrepancies in the care provided to patients with NAFLD by hepatologists practicing in academic centers across Canada. METHODS: A nationwide survey was distributed electronically to all pediatric hepatologists practicing in university-affiliated hospitals using the infrastructure of the Canadian Pediatric Hepatology Research Group. The responses were anonymous. RESULTS: The response rate to the survey was 79%. Everyone reported diagnosing NAFLD based on a combination of elevated transaminases and imaging suggestive of steatosis in the context of an otherwise negative workup for other liver diseases. Only 14% use liver biopsy to confirm the diagnosis. There are significant discrepancies in the frequency of screening for other comorbidities (eg, hypertension, sleep apnea, etc) and in the frequency of laboratory investigations (eg, lipid profile, transaminases, international normalized ratio, etc). Frequency of outpatient clinic follow-up varies significantly. Treatment is consistently based on lifestyle modifications; however, reported patient outcomes in terms of body mass index improvements are poor. CONCLUSIONS: There are significant discrepancies in the care provided to children with NAFLD by hepatologists practicing in academic centers across Canada.

A national retrospective study of paediatric end-stage liver disease as a predictor of change to second-line therapy in children with autoimmune hepatitis.

BACKGROUND & AIMS: Adult studies of autoimmune hepatitis (AIH) have shown that the model of end-stage liver disease is associated with resistance to first-line treatment. Using a multicentre retrospective database, we sought to determine if the paediatric end-stage liver disease (PELD) score would similarly predict treatment resistance in paediatric AIH. METHODS: One hundred and seventy-one children from 13 Canadian centres who fulfilled the International Autoimmune Hepatitis Group (IAIHG) criteria were included and assessed for change to second-line therapy within 24 months of primary treatment onset. Those with PSC overlap at presentation, or missing data on the PELD variables were excluded. PELD was calculated for all remaining patients. Univariate analysis and receiver-operator characteristic (ROC) curves were performed to determine the predictive ability of the PELD score to change to second-line therapy. RESULTS: A total of 103 children were included with median age of 11 years (range 2-17). Mean PELD was -2.51±8.58. Second-line therapy was used within 24 months of diagnosis in 13 patients. Univariate analysis revealed that change to second-line therapy was associated with higher PELD (P=.028) and internal normalized ratio (INR) (P=.011). ROC curves for PELD and its individual components were performed. The strength of association was strongest with INR (AUC 0.72; CI: 0.58-0.86) although the composite PELD score also showed some predictive ability (AUC 0.67; CI: 0.52-0.81). CONCLUSION: In this paediatric AIH cohort, higher PELD at presentation predicted change to second-line therapy within the first 2 years of follow-up. INR appeared to be the main contributor to that association.