Wiskott-Aldrich syndrome: a study of 577 patients defines the genotype as a biomarker for disease severity and survival.

ABSTRACT: Wiskott-Aldrich syndrome (WAS) is a multifaceted monogenic disorder with a broad disease spectrum and variable disease severity and a variety of treatment options including allogeneic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT). No reliable biomarker exists to predict disease course and outcome for individual patients. A total of 577 patients with a WAS variant from 26 countries and a median follow-up of 8.9 years (range, 0.3-71.1), totaling 6118 patient-years, were included in this international retrospective study. Overall survival (OS) of the cohort (censored at HSCT or GT) was 82% (95% confidence interval, 78-87) at age 15 years and 70% (61-80) at 30 years. The type of variant was predictive of outcome: patients with a missense variant in exons 1 or 2 or with the intronic hot spot variant c.559+5G>A (class I variants) had a 15-year OS of 93% (89-98) and a 30-year OS of 91% (86-97), compared with 71% (62-81) and 48% (34-68) in patients with any other variant (class II; P < .0001). The cumulative incidence rates of disease-related complications such as severe bleeding (P = .007), life-threatening infection (P < .0001), and autoimmunity (P = .004) occurred significantly later in patients with a class I variant. The cumulative incidence of malignancy (P = .6) was not different between classes I and II. It confirms the spectrum of disease severity and quantifies the risk for specific disease-related complications. The class of the variant is a biomarker to predict the outcome for patients with WAS.

Humoral and cellular immunogenicity, effectiveness and safety of COVID-19 mRNA vaccination in patients with pediatric rheumatic diseases: A prospective cohort study.

OBJECTIVES: To evaluate immunogenicity, effectiveness and safety of COVID-19 vaccination in patients with pediatric autoimmune inflammatory rheumatic disease (pedAIIRD). METHODS: A prospective cohort study was performed at the pediatric rheumatology department of the Wilhelmina Children's Hospital in Utrecht, the Netherlands. Vaccination dates, COVID-19 cases and vaccine-related adverse events (AEs) were registered for all pedAIIRD patients during regular clinic visits from March 2021 - August 2022. SARS-CoV-2 IgG antibody levels and T-cell responses were measured from serum samples after vaccination, and clinical and drug therapy data were collected from electronic medical records. Rate of COVID-19 disease was compared between vaccinated and unvaccinated patients in a time-varying Cox regression analysis. RESULTS: A total of 157 patients were included in this study and 88 % had juvenile idiopathic arthritis (JIA). One hundred thirty-seven patients were fully vaccinated, of which 47 % used biological agents at the time of vaccination, and 20 patients were unvaccinated. Geometric mean concentrations (GMCs) of post-vaccine antibody levels against SARS-CoV-2 were above the threshold for positivity in patients who did and did not use biological agents at the time of vaccination, although biological users demonstrated significantly lower antibody levels (adjusted GMC ratio: 0.38, 95 % CI: 0.21 - 0.70). T-cell responses were adequate in all but two patients (9 %). The adjusted rate of reported COVID-19 was significantly lower for fully vaccinated patients compared to non-vaccinated patients (HR: 0.53, 95 % CI: 0.29 - 0.97). JIA disease activity scores were not significantly different after vaccination, and no serious AEs were reported. CONCLUSIONS: COVID-19 mRNA vaccines were immunogenic (both cellular and humoral), effective and safe in a large cohort of pedAIIRD patients despite their use of immunosuppressive medication.

Pulmonary Computed Tomography Screening Frequency in Primary Antibody Deficiency.

BACKGROUND: Patients with primary antibody deficiency (PAD) frequently suffer from pulmonary complications, associated with severe morbidity and mortality. Hence, regular pulmonary screening by computed tomography (CT) scanning is advised. However, predictive risk factors for pulmonary morbidity are lacking. OBJECTIVE: To identify patients with PAD at risk for pulmonary complications necessitating regular CT screening. METHODS: A retrospective, longitudinal cohort study of patients with PAD (median follow-up 7.4 [2.3-14.8] years) was performed. CTs were scored using the modified Brody-II scoring system. Clinical and laboratory parameters were retrospectively collected. Potential risk factors were identified by univariate analysis when P < .2 and confirmed by multivariable logistic regression when P < .05. RESULTS: The following independent risk factors for progression of airway disease (AD) were identified: (1) diagnosis of X-linked agammaglobulinemia (XLA), (2) recurrent airway infections (2.5/year), and (3) the presence of AD at baseline. Signs of AD progression were detected in 5 of 11 patients with XLA and in 17 of 80 of the other patients with PAD. Of the 22 patients who progressed, 17 had pre-existent AD scores ≥7.0%. Increased AD scores were related to poorer forced expiratory volume in 1 second values and chronic cough. Common variable immunodeficiency and increased CD4 effector/memory cells were risk factors for an interstitial lung disease (ILD) score ≥13.0%. ILD ≥13.0% occurred in 12 of 80 patients. Signs of ILD progression were detected in 8 of 80 patients, and 4 of 8 patients showing progression had pre-existent ILD scores ≥13.0%. CONCLUSION: We identified risk factors that distinguished patients with PAD at risk for AD and ILD presence and progression, which could guide future screening frequency; however, independent and preferably prospective validation is needed.

Neurological phenotype of adenosine deaminase 2 deficient patients: a cohort study.

BACKGROUND AND PURPOSE: Patients with adenosine deaminase 2 (ADA2) deficiency can present with various neurological manifestations due to vasculopathies and autoinflammation. These include ischaemic and hemorrhagic stroke, but less clearly defined neurological symptoms have also been reported. METHODS: In this cohort study, patients with confirmed ADA2 deficiency from seven university hospitals in the Netherlands were included. The frequency and recurrence rates of neurological manifestations before and after initiation of tumor necrosis factor α (TNF-α) inhibiting therapy were analyzed. RESULTS: Twenty-nine patients were included with a median age at presentation of 5 years (interquartile range 1-17). Neurological manifestations occurred in 19/29 (66%) patients and were the presenting symptom in 9/29 (31%) patients. Transient ischaemic attack (TIA)/ischaemic stroke occurred in 12/29 (41%) patients and was the presenting symptom in 8/29 (28%) patients. In total, 25 TIAs/ischaemic strokes occurred in 12 patients, one after initiation of TNF-α inhibiting therapy and one whilst switching between TNF-α inhibitors. None was large-vessel occlusion stroke. Two hemorrhagic strokes occurred: one aneurysmatic subarachnoid hemorrhage and one spontaneous intracerebral hemorrhage. Most neurological symptoms, including cranial nerve deficits, vertigo, ataxia and seizures, were caused by TIAs/ischaemic strokes and seldom recurred after initiation of TNF-α inhibiting therapy. CONCLUSIONS: Neurological manifestations, especially TIA/ischaemic stroke, are common in patients with ADA2 deficiency and frequently are the presenting symptom. Because it is a treatable cause of young stroke, for which antiplatelet and anticoagulant therapy are considered contraindicated, awareness amongst neurologists and pediatricians is important. Screening for ADA2 deficiency in young patients with small-vessel ischaemic stroke without an identified cause should be considered.

Antibody deficiencies in children are associated with prematurity and a family history of infections.

BACKGROUND: Recurrent respiratory tract infections (rRTIs) frequently affect young children and are associated with antibody deficiencies. We investigated the prevalence of and epidemiological risk factors associated with antibody deficiencies in young children with rRTIs and their progression over time, and linked these to prospectively measured RTI symptoms. METHODS: We included children <7 years with rRTIs in a prospective cohort study. Patient characteristics associated with antibody deficiencies were identified using multivariable logistic regression analysis. RESULTS: We included 146 children with a median age of 3.1 years. Daily RTI symptoms were monitored in winter in n = 73 children and repeated immunoglobulin level measurements were performed in n = 45 children. Antibody deficiency was diagnosed in 56% and associated with prematurity (OR 3.17 [1.15-10.29]) and a family history of rRTIs (OR 2.37 [1.11-5.15]). Respiratory symptoms did not differ between children with and without antibody deficiencies. During follow-up, antibody deficiency diagnosis remained unchanged in 67%, while 18% of children progressed to a more severe phenotype. CONCLUSION: Immune maturation and genetic predisposition may lie at the basis of antibody deficiencies commonly observed in early life. Because disease severity did not differ between children with and without antibody deficiency, we suggest symptom management can be similar for all children with rRTIs. IMPACT: An antibody deficiency was present in 56% of children <7 years with recurrent respiratory tract infections (rRTIs) in a Dutch tertiary hospital setting. Prematurity and a family history of rRTIs were associated with antibody deficiencies, suggesting that immune maturation and genetic predisposition may lie at the basis of antibody deficiencies in early life. RTI symptoms did not differ between children with and without antibody deficiency, suggesting that symptom management can be similar for all children with rRTIs, irrespective of humoral immunological deficiencies. During follow-up, 18% of children progressed to a more severe phenotype, emphasizing that early diagnosis is warranted to prevent long-term morbidity and increase quality of life.

Clinical Symptoms, Laboratory Parameters and Long-Term Follow-up in a National DADA2 Cohort.

Deficiency of adenosine deaminase-2 (DADA2) is an autosomal recessive autoinflammatory disease with an extremely variable disease presentation. This paper provides a comprehensive overview of the Dutch DADA2 cohort. We performed a retrospective cohort study in 29 ADA2-deficient patients from 23 families with a median age at inclusion of 26 years. All patients had biallelic pathogenic variants in the ADA2 gene. The most common clinical findings included cutaneous involvement (79.3%), (hepato)splenomegaly (70.8%) and recurrent infections (58.6%). Stroke was observed in 41.4% of the patients. The main laboratory abnormalities were hypogammaglobulinemia and various cytopenias. Patients presented most often with a mixed phenotype involving vasculopathy, immunodeficiency and hematologic manifestations (62.1%). In this cohort, malignancies were reported in eight patients (27.6%), of whom five presented with a hematologic malignancy and two with a basal cell carcinoma. Four patients developed hemophagocytic lymphohistiocytosis (HLH) or an HLH-like episode, of whom three passed away during or shortly after the occurrence of HLH. TNF-inhibitors (TNFi) were effective in treating vasculopathy-associated symptoms and preventing stroke, but were hardly effective in the treatment of hematologic manifestations. Three patients underwent hematopoietic cell transplantation and two of them are doing well with complete resolution of DADA2-related symptoms. The overall mortality in this cohort was 17.2%. In conclusion, this cohort describes the clinical, genetic and laboratory findings of 29 Dutch DADA2 patients. We describe the occurrence of HLH as a life-threatening disease complication and report a relatively high incidence of malignancies and mortality.

Development of a primary care screening algorithm for the early detection of patients at risk of primary antibody deficiency.

BACKGROUND: Primary antibody deficiencies (PAD) are characterized by a heterogeneous clinical presentation and low prevalence, contributing to a median diagnostic delay of 3-10 years. This increases the risk of morbidity and mortality from undiagnosed PAD, which may be prevented with adequate therapy. To reduce the diagnostic delay of PAD, we developed a screening algorithm using primary care electronic health record (EHR) data to identify patients at risk of PAD. This screening algorithm can be used as an aid to notify general practitioners when further laboratory evaluation of immunoglobulins should be considered, thereby facilitating a timely diagnosis of PAD. METHODS: Candidate components for the algorithm were based on a broad range of presenting signs and symptoms of PAD that are available in primary care EHRs. The decision on inclusion and weight of the components in the algorithm was based on the prevalence of these components among PAD patients and control groups, as well as clinical rationale. RESULTS: We analyzed the primary care EHRs of 30 PAD patients, 26 primary care immunodeficiency patients and 58,223 control patients. The median diagnostic delay of PAD patients was 9.5 years. Several candidate components showed a clear difference in prevalence between PAD patients and controls, most notably the mean number of antibiotic prescriptions in the 4 years prior to diagnosis (5.14 vs. 0.48). The final algorithm included antibiotic prescriptions, diagnostic codes for respiratory tract and other infections, gastro-intestinal complaints, auto-immune symptoms, malignancies and lymphoproliferative symptoms, as well as laboratory values and visits to the general practitioner. CONCLUSIONS: In this study, we developed a screening algorithm based on a broad range of presenting signs and symptoms of PAD, which is suitable to implement in primary care. It has the potential to considerably reduce diagnostic delay in PAD, and will be validated in a prospective study. Trial registration The consecutive prospective study is registered at clinicaltrials.gov under NCT05310604.

Meningococcal ACWY conjugate vaccine immunogenicity and safety in adolescents with juvenile idiopathic arthritis and inflammatory bowel disease: A prospective observational cohort study.

BACKGROUND: Immunogenicity to meningococcal serogroup ACWY (MenACWY) conjugate vaccine has not been studied in immunocompromised minors with juvenile idiopathic arthritis (JIA) or inflammatory bowel disease (IBD). We determined immunogenicity of a MenACWY-TT vaccine in JIA and IBD patients at adolescent age and compared results to data from aged-matched healthy controls (HCs). METHODS: We performed a prospective observational cohort study in JIA and IBD patients (14-18 years old), who received a MenACWY vaccination during a nationwide catch-up campaign (2018-2019) in the Netherlands. Primary aim was to compare MenACWY polysaccharide-specific serum IgG geometric mean concentrations (GMCs) in patients with HCs and secondary between patients with or without anti-TNF therapy. GMCs were determined before and 3-6, 12, and 24 months postvaccination and compared with data from HCs at baseline and 12 months postvaccination. Serum bactericidal antibody (SBA) titers were determined in a subset of patients at 12 months postvaccination. RESULTS: We included 226 JIA and IBD patients (66 % and 34 % respectively). GMCs were lower for MenA and MenW (GMC ratio 0·24 [0·17-0·34] and 0·16 [0·10-0·26] respectively, p < 0·01) in patients compared to HCs at 12 months postvaccination. Anti-TNF users had lower MenACWY GMCs postvaccination compared with those without anti-TNF (p < 0·01). The proportion protected (SBA ≥ 8) for MenW was reduced in anti-TNF users (76 % versus 92 % in non-anti-TNF and 100 % in HCs, p < 0.01). CONCLUSION: The MenACWY conjugate vaccine was immunogenic in the vast majority of JIA and IBD patients at adolescent age, but seroprotection was lower in patients using anti-TNF agents. Therefore, an extra booster MenACWY vaccination should be considered.

Evaluation and Management of Deficiency of Adenosine Deaminase 2: An International Consensus Statement.

Importance: Deficiency of adenosine deaminase 2 (DADA2) is a recessively inherited disease characterized by systemic vasculitis, early-onset stroke, bone marrow failure, and/or immunodeficiency affecting both children and adults. DADA2 is among the more common monogenic autoinflammatory diseases, with an estimate of more than 35 000 cases worldwide, but currently, there are no guidelines for diagnostic evaluation or management. Objective: To review the available evidence and develop multidisciplinary consensus statements for the evaluation and management of DADA2. Evidence Review: The DADA2 Consensus Committee developed research questions based on data collected from the International Meetings on DADA2 organized by the DADA2 Foundation in 2016, 2018, and 2020. A comprehensive literature review was performed for articles published prior to 2022. Thirty-two consensus statements were generated using a modified Delphi process, and evidence was graded using the Oxford Center for Evidence-Based Medicine Levels of Evidence. Findings: The DADA2 Consensus Committee, comprising 3 patient representatives and 35 international experts from 18 countries, developed consensus statements for (1) diagnostic testing, (2) screening, (3) clinical and laboratory evaluation, and (4) management of DADA2 based on disease phenotype. Additional consensus statements related to the evaluation and treatment of individuals with DADA2 who are presymptomatic and carriers were generated. Areas with insufficient evidence were identified, and questions for future research were outlined. Conclusions and Relevance: DADA2 is a potentially fatal disease that requires early diagnosis and treatment. By summarizing key evidence and expert opinions, these consensus statements provide a framework to facilitate diagnostic evaluation and management of DADA2.

Retropharyngeal abscess-like as an atypical presentation of Kawasaki disease: a case report and literature review.

BACKGROUND: Kawasaki disease (KD) is a systemic inflammatory condition primarily affecting young children. Although 90% of KD patients present with variable head and neck manifestations, especially cervical lymphadenopathy, peritonsillar, retropharyngeal and parapharyngeal involvement are uncommonly reported as initial manifestations of KD. CASE REPORT: Eight-year-old girl with prolonged fever, clinical and a radiological picture suggestive of retropharyngeal abscess, unresponsive to three changes in the antibiotic regimen and surgical drainage. The disease progressed with the development of additional signs and symptoms as non-purulent conjunctivitis (with uveitis), mucosal involvement (strawberry tongue and cracked lips), edema of her hands and feet, and arthritis. A diagnosis of Kawasaki disease was reached with complete remission after Intravenous Immunoglobulin (IVIG) treatment. In addition, we present a literature review of similar cases reported in the last thirty years. CONCLUSION: Kawasaki disease requires a high index of suspicion and awareness of unusual presentations. It should be kept in mind as one of the differential diagnosis of patients with febrile inflammation of the retropharyngeal and parapharyngeal spaces who do not respond to antibiotic treatment in the relevant clinical context.