N-acetylcysteine (NAC) was found to improve transplantation-free survival in only those adults with non-acetaminophen (non-APAP) acute liver failure (ALF) and grade 1–2 hepatic encephalopathy (HE). Because non-APAP ALF differs significantly between children and adults, the Pediatric Acute Liver Failure (PALF) Study Group evaluated NAC in non-APAP PALF. Children from birth through age 17 years with non-APAP ALF enrolled in the PALF registry were eligible to enter an adaptively allocated, doubly masked, placebo-controlled trial using a continuous intravenous infusion of NAC (150 mg/kg/day in 5% dextrose in water [D5W]) or placebo (D5W) for up to 7 days. The primary outcome was 1-year survival. Secondary outcomes included liver transplantation-free survival, liver transplantation (LTx), length of ICU and hospital stays, organ system failure and maximum HE score. A total of 184 participants were enrolled in the trial with 92 in each arm. The 1-year survival did not differ significantly (p=0.19) between the NAC (73%) and placebo (82%) treatment groups. The 1-year LTx-free survival was significantly lower (p=0.03) in those who received NAC (35%) than those who received placebo (53%), particularly, but not significantly so, among those less than 2 years old with HE grade 0–1 (NAC 25%; placebo 60%; p=0.0493). There were no significant differences between treatment arms for hospital or ICU length of stay, organ systems failing, or highest recorded grade of HE. Conclusion NAC did not improve 1-year survival in non-APAP PALF. 1-year LTx-free survival was significantly lower with NAC, particularly among those < 2 years old. These results do not support broad use of NAC in non-APAP PALF and emphasizes the importance of conducting controlled pediatric drug trials, regardless of results in adults.

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Background Dedicator of cytokinesis 8 (DOCK8) deficiency can be cured by allogeneic hematopoietic stem cell transplantation (HSCT). Reports of outcome are still limited. Objective To analyze the results of HSCT in patients with DOCK8 deficiency and report whether approaches resulting in mixed chimerism result in clinically relevant immune reconstitution. Methods We performed retrospective chart review of 11 patients with DOCK8 deficiency, and measured DOCK8 expression and cytokine production. Results Of 11 patients, 7 received HSCT from related and 4 from unrelated donors; nine patients received busulfan-based conditioning regimens. Survival was excellent (10/11 patients alive, 91%), including a patient who had undergone liver transplantation. Patients showed significant improvements in the frequency and severity of infections. While eczema resolved in all, food allergies and high IgE levels persisted in some patients. Lymphopenia, eosinophilia, low numbers of naïve CD8+ T cells and switched memory B cells, and Th1/Th2 cytokine imbalance improved in most patients. While the 8 matched related or unrelated donor recipients had full donor chimerism, all 3 recipients of mismatched unrelated donor HSCT had high levels of donor T cell chimerism, and low B and myeloid chimerism (0–46%). Almost all switched memory B cells were of donor origin. All patients including those with mixed chimerism mounted robust antibody responses to vaccination. Conclusion Allogeneic HSCT ameliorated the infectious and atopic symptoms of DOCK8 deficiency. In patients with mixed chimerism, selective advantage for donor-derived T cells and switched memory B cells promoted restoration of cellular and humoral immunity and protection against opportunistic infection.

Background Immune cytopenias are a recognized life-threatening complication following pediatric solid organ transplants (SOT), but treatment responses and overall outcome are not well described. The aim of this study was to evaluate the demographic characteristics, response to treatments, and outcomes of a cohort of patients who developed immune cytopenias following SOT. Methods In this single center retrospective review, patients with immune cytopenias after SOT were identified by electronic medical record (EMR) search and transplant databases from 1995-2012. Results Of 764 SOT patients, 19 (2.4%) developed immune cytopenias. Incidence varied widely by transplant type from 1.2% (renal) to 23.5% (multivisceral). Autoimmune hemolytic anemia (AIHA) was the most common immune cytopenia. Overall median time from transplant to immune cytopenia was 8 m and varied by transplant type from 3 m (liver) to 74 m (heart). Standard therapies for immune cytopenias were often used and ineffective. The most effective therapy for the immune cytopenia was changing immunosuppression from tacrolimus to another agent. Three of 19 patients died; none directly attributed to the immune cytopenia. Conclusions Immune cytopenias are not rare after SOT, and patients usually do not respond well to traditional first line therapies. Provided that the risk of organ rejection is otherwise manageable, temporary cessation of tacrolimus could be more widely explored in this challenging clinical context.

Objective: Increased mortality risk because of severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) infection in adults with native liver disease (LD) and liver transplant (LT) is associated with advanced age and comorbid conditions. We aim to report outcomes for children with LD and LT enrolled in the NASPGHAN/SPLIT SARS-CoV2 registry. Methods: In this multicenter observational cohort study, we collected data from 91 patients <21 years (LD 44, LT 47) with laboratory-confirmed SARS-CoV2 infection between April 21 and September 17, 2020. Results: Patients with LD were more likely to require admission (70% vs 43% LT, P = 0.007) and pediatric intensive care unit (PICU) management (32% vs 4% LT, P = 0.001). Seven LD patients required mechanical ventilation (MV) and 2 patients died; no patients in the LT cohort died or required MV. Four LD patients presented in pediatric acute liver failure (PALF), 2 with concurrent multisystem inflammatory syndrome in children (MIS-C); all recovered without LT. Two LD patients had MIS-C alone and 1 patient died. Bivariable logistic-regression analysis found that patients with nonalcoholic fatty LD (NAFLD) (odds ratio [OR] 5.6, P = 0.02) and LD (OR 6.1, P = 0.01, vs LT) had higher odds of severe disease (PICU, vasopressor support, MV, renal replacement therapy or death). Conclusions: Although not directly comparable, LT recipients had lower odds of severe SARS-CoV2 infection (vs LD), despite immunosuppression burden. NAFLD patients reported to the registry had higher odds of severe SARS-CoV2 disease. Future controlled studies are needed to evaluate effective treatments and further stratify LD and LT patients with SARS-CoV2 infection.