Introduction Haploinsufficiency of A20 (HA20) is a monogenic disease caused by heterozygous TNFAIP3 variants. Despite the marked clinical variability, no genotype–phenotype correlation or validated laboratory biomarkers have been identified so far. Neurobehavioural abnormalities have been reported in murine models, but their prevalence in humans remains unclear.Objectives To describe a cohort of patients with HA20 from two centres, evaluating age-related clinical variability; to assess the prevalence of neuropsychiatric symptoms; to explore the inflammatory profile of the patients, including interferon (IFN)-γ-inducible chemokines (CXCL9/10) and type 1 IFN signature (IS), as well as the therapies administered.Methods Clinical and laboratory data of 17 subjects from six families heterozygous for TNFAIP3 variants (American College of Medical Genetics and Genomics class 4–5) were retrospectively collected. Disease activity, treatments, CXCL9/10 and IS levels were collected. Continuous variables were expressed as medians (IQR). Age at onset was compared using the Kruskal-Wallis test, and groups were compared through the Wilcoxon test or Fisher’s exact test.Results Clinical manifestations included oral aphthosis (88%), recurrent fever (53%), gastrointestinal inflammation (53%), autoimmunity (47%), genital ulcers (47%), neuropsychiatric symptoms (41%), arthritis/tenosynovitis (18%) and skin inflammation (12%). Disease onset before 5 years of age was associated with a higher prevalence of neuropsychiatric symptoms during lifetime (p=0.004), whereas arthritis was more common in patients with later onset. The median age at onset differed significantly according to the type of clinical manifestation (p<0.001). Higher IS levels were found in patients with active disease (p<0.01).Conclusions HA20 shows marked clinical heterogeneity both between and within families. Clinical manifestations appear age-related and early disease onset was associated with increased neuropsychiatric involvement lifetime. Finally, type 1 IS may represent a potential biomarker of disease activity in HA20.

BackgroundAutoinflammatory diseases (AIDs) are a group of disease characterized by excessive activation of the innate immune system with episodes of spontaneous inflammation that can affect different organs. Many monogenic or acquired autoinflammatory diseases are described in literature. More recently the concept of disease with polygenic or complex inheritance has been introduced. Nucleotide binding oligomerization domain containing 2 (NOD2) gene variants are associated with Crohn’s disease (CD), Blau syndrome and most recently with a polygenic autoinflammatory disease with onset in adult called NOD2-associated autoinflammatory disease (NAID).ObjectiveThe aim of our study is to describe a pediatric cohort of patients with autoinflammatory disease carrying NOD2 variants and to evaluate genotype-phenotype correlation.MethodsTwenty-five children with autoinflammatory disease and NOD2 variants were enrolled in the study. Patients were divided into 3 groups based on the protein domain involved. Demographic and clinical features, imaging, laboratory exams and treatment were analyzed. The characteristics of our patients were compared with those of the adult cohort described by Yao in 2016-2018.ResultsFever was the main clinical characteristic of our children (68%) with long episodes and irregular pattern of recurrence. The disease typically affected skin (40%), joints (72%), bowel (60%) and lymphatic system (52%). Serositis and sensorineural deafness were less frequent. Excluding non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids were frequently used with satisfactory clinical response in the majority of patients. In patients with poor disease control or new flares after glucocorticoid tapering, non-biologic and biologic drugs were used with variable response. The comparison between the two most represented groups showed that patients with variants located on the NOD domain presented more homogeneous clinical characteristics with involvement of some target organs. Our patients were compared with the adult cohort described in literature with few differences.ConclusionThis is the first study to evaluate genotypic/phenotypic characteristics of children with systemic autoinflammatory disease and NOD2 variants. The results, albeit preliminary and affected by the sample size, do not allow a definitive conclusion on a monogenic disease caused by mutation in NOD2, with the obvious exception of Blau syndrome. Variants in the NOD domain seem to be associated with a more homogenous clinical phenotype.

Background/Objectives: The nuclear factor (NF)-kB essential modulator (NEMO) has a crucial role in the NFκB pathway. Hypomorphic IKBKG pathogenic variants cause ectodermal dysplasia with immunodeficiency (EDA-ID) in affected males. However, heterozygous amorphic IKBKG variants could be responsible for Incontinentia Pigmenti (IP) in female carriers. Typically, IP patients do not exhibit immunodeficiency, although hypomorphic variants might lead to immunodeficiency in female IP patients. Here, we report the case of an IKBKG female carrier, with no IP but an unexpected picture of immunodeficiency. She had a positive family history for the same genetic condition. Methods: We performed immunological, molecular, and functional analysis to evaluate NEMO contribution. Results: The patient was healthy until the age of 25 when severe asthma and Hashimoto thyroiditis occurred. She had HLAB27-positive ankylosing spondylitis, non-tubercular mycobacteriosis, and pulmonary aspergillosis infections. We found CD19+ B cell lymphopenia and T cell subset alterations. Sanger sequencing revealed a heterozygous IKBKG variant at position +1 of the 5' UTR of the gene which disrupted the normal pre-mRNA splicing. We observed a decreased NEMO protein expression, a reduced level of mRNA, and a defective NF-κB pathway. Conclusions: These findings suggest a possible correlation between the partial loss of NEMO function and the immunodeficiency observed in this patient. This case could expand our understanding of NEMO deficiency in female carriers.

Chronic granulomatous disease (CGD) is a human IEI caused by mutations in genes encoding the NADPH oxidase subunits, the enzyme responsible for the respiratory burst. CGD patients have severe life-threatening infections, hyperinflammation and immune dysregulation. Recently, an additional autosomal recessive AR-CGD (type 5) caused by mutations in CYBC1/EROS gene was identified.We report a AR-CGD5 patient with a novel loss of function (LOF) homozygous deletion c.8_7del in the CYBC1 gene including the initiation ATG codon that leads to failure of CYBC1/EROS protein expression and presenting with an unusual clinical manifestation of childhood-onset sarcoidosis-like disease requiring multiple immuno-suppressive therapies. We described an abnormal gp91phox protein expression/function in the patient's neu-trophils and monocytes (about 50%) and a severely compromised B cell subset (gp91phox < 15%; DHR+ < 4%).Our case-report emphasized the importance of considering a diagnosis of AR-CGD5 deficiency even in absence of typical clinical and laboratory findings.

ObjectiveTo evaluate the impact of early treatment and IL1RN genetic variants on the response to anakinra in systemic juvenile idiopathic arthritis (JIA).MethodsResponse to anakinra was defined as achievement of clinically inactive disease (CID) at 6 months without glucocorticoid treatment. Demographic, clinical, and laboratory characteristics of 56 patients were evaluated in univariate and multivariate analyses as predictors of response to treatment. Six single‐nucleotide polymorphisms (SNPs) in the IL1RN gene, previously demonstrated to be associated with a poor response to anakinra, were genotyped by quantitative polymerase chain reaction (qPCR) or Sanger sequencing. Haplotype mapping was performed with Haploview software. IL1RN messenger RNA (mRNA) expression in whole blood from patients, prior to anakinra treatment initiation, was assessed by qPCR.ResultsAfter 6 months of anakinra treatment, 73.2% of patients met the criteria for CID without receiving glucocorticoids. In the univariate analysis, the variable most strongly related to the response was disease duration from onset to initiation of anakinra treatment, with an optimal cutoff at 3 months (area under the curve 84.1%). Patients who started anakinra treatment ≥3 months after disease onset had an 8‐fold higher risk of nonresponse at 6 months of treatment. We confirmed that the 6 IL1RN SNPs were inherited as a common haplotype. We found that homozygosity for ≥1 high‐expression SNP correlated with higher IL1RN mRNA levels and was associated with a 6‐fold higher risk of nonresponse, independent of disease duration.ConclusionOur findings on patients with systemic JIA confirm the important role of early interleukin‐1 inhibition and suggest that genetic IL1RN variants predict nonresponse to therapy with anakinra.