Background: An unclassified primary antibody deficiency (unPAD) is a widely heterogeneous clinical entity, recently identified within the spectrum of Inborn Errors of Immunity (IEIs). Since unPAD has been traditionally considered as a mild condition, it has incorrectly received little attention, resulting in the paucity of extensive and comparable studies describing its natural history. To address the gaps in characterizing, understanding, and managing pediatric unPAD patients, the Italian Primary Immunodeficiency Network (IPINet) Ped-unPAD study has recently been launched. Methods: Seventeen IPINeT Centers have expressed interest to participate, and data collection is still on-going. Hereby, we anticipate preliminary key issues emerging from the first 110 enrolled patients, attending three IPINet Centers. Results: A proportion of unPAD patients have experienced a severe infectious phenotype, which required hospitalization in a quarter of patients and antibiotic prophylaxis or Immunoglobulin Replacement Therapy in approximately 10% of patients. In this partial cohort, a mean follow-up (FU) of 5 years confirmed unPAD diagnosis in fifty percent of cases, with the remaining being reclassified as the Transient Hypogammaglobulinemia of Infancy (25%) and other IEIs (25%), such as a Common Variable Immunodeficiency, Selective IgA deficiency, Selective IgM deficiency, and IgG3 subclass deficiency. Conclusions: Despite a phenotype overlap at diagnosis, clinicians should be aware that unPAD is a mutable condition that deserves comprehensive evaluation and long-term monitoring to dissect the final diagnosis for optimal treatment.

Hypogammaglobulinemia without B-cells is a subgroup of inborn errors of immunity (IEI) which is characterized by a significant decline in all serum immunoglobulin isotypes, coupled with a pronounced reduction or absence of B-cells. Approximately 80 to 90% of individuals exhibit genetic variations in Bruton\'s agammaglobulinemia tyrosine kinase (BTK), whereas a minority of cases, around 5-10%, are autosomal recessive agammaglobulinemia (ARA). Very few cases are grouped into distinct subcategories. We evaluated phenotypically and genetically 27 patients from 13 distinct families with hypogammaglobinemia and no B-cells. Genetic analysis was performed via whole-exome and Sanger sequencing. The most prevalent genetic cause was mutations in BTK. Three novel mutations in the BTK gene include c.115 T > C (p. Tyr39His), c.685-686insTTAC (p.Asn229llefs5), and c.163delT (p.Ser55GlnfsTer2). Our three ARA patients include a novel homozygous stop-gain mutation in the immunoglobulin heavy constant Mu chain (IGHM) gene, a novel frameshift mutation of the B-cell antigen receptor complex-associated protein (CD79A) gene, a novel bi-allelic stop-gain mutation in the transcription factor 3 (TCF3) gene. Three patients with agammaglobulinemia have an autosomal dominant inheritance pattern, which includes a missense variant in PIK3CD, a novel missense variant in PIK3R1 and a homozygous silent mutation in the phosphoinositide-3-kinase regulatory subunit (RASGRP1) gene. This study broadens the genetic spectrum of hypogammaglobulinemia without B-cells and presented a few novel variants within the Iranian community, which may also have implications in other Middle Eastern populations. Notably, disease control was better in the second affected family member in families with multiple cases.

Kabuki Syndrome (KS) is a multisystemic genetic disorder. A portion of patients has immunological manifestations characterized by increased susceptibility to infections and autoimmunity. Aiming to describe the clinical and laboratory immunological aspects of KS, we conducted a retrospective multicenter observational study on patients with KS treated in centers affiliated to the Italian Primary Immunodeficiency Network.Thirty-nine patients were enrolled, with a median age at evaluation of 10 years (range: 3 m-21y). All individuals had organ malformations of variable severity. Congenital heart defect (CHD) was present in 19/39 patients (49%) and required surgical correction in 9/39 (23%), with associated thymectomy in 7/39 (18%). Autoimmune cytopenia occurred in 6/39 patients (15%) and was significantly correlated with thymectomy (p < 0.002), but not CHD. Individuals with cytopenia treated with mycophenolate as long-term immunomodulatory treatment (n = 4) showed complete response. Increased susceptibility to infections was observed in 22/32 patients (69%). IgG, IgA, and IgM were low in 13/29 (45%), 13/30 (43%) and 4/29 (14%) patients, respectively. Immunoglobulin substitution was required in three patients. Lymphocyte subsets were normal in all patients except for reduced naïve T-cells in 3/15 patients (20%) and reduced memory switched B-cells in 3/17 patients (18%). Elevated CD3 + TCRαβ + CD4-CD8-T-cells were present in 5/17 individuals (23%) and were correlated with hematological and overall autoimmunity (p < 0.05).In conclusion, immunological manifestations of KS in our cohort include susceptibility to infections, antibody deficiency, and autoimmunity. Autoimmune cytopenia is correlated with thymectomy and elevated CD3 + TCRαβ + CD4-CD8-T-cells, and benefits from treatment with mycophenolate.

Newborn screening (NBS) for severe inborn errors of immunity (IEI), affecting T lymphocytes, and implementing measurements of T cell receptor excision circles (TREC) has been shown to be effective in early diagnosis and improved prognosis of patients with these genetic disorders. Few studies conducted on smaller groups of newborns report results of NBS that also include measurement of kappa-deleting recombination excision circles (KREC) for IEI affecting B lymphocytes. A pilot NBS study utilizing TREC/KREC detection was conducted on 202,908 infants born in 8 regions of Russia over a 14-month period. One hundred thirty-four newborns (0.66‰) were NBS positive after the first test and subsequent retest, 41% of whom were born preterm. After lymphocyte subsets were assessed via flow cytometry, samples of 18 infants (0.09‰) were sent for whole exome sequencing. Confirmed genetic defects were consistent with autosomal recessive agammaglobulinemia in 1/18, severe combined immunodeficiency - in 7/18, 22q11.2DS syndrome - in 4/18, combined immunodeficiency - in 1/18 and trisomy 21 syndrome - in 1/18. Two patients in whom no genetic defect was found met criteria of (severe) combined immunodeficiency with syndromic features. Three patients appeared to have transient lymphopenia. Our findings demonstrate the value of implementing combined TREC/KREC NBS screening and inform the development of policies and guidelines for its integration into routine newborn screening programs.

OBJECTIVE: To investigate the incidence, clinical and genetic characteristics of pediatric lymphoma patients of China with inborn errors of immunity (IEI)-related gene mutations, which have not been fully studied.
METHODS: From Jan. 2020 to Mar. 2023, IEI-related genetic mutations were retrospectively explored in 108 children with lymphomas admitted to Beijing Children\'s Hospital by NGS. Genetic rule and clinical characteristics as well as treatment outcomes were compared between patients with or without IEI-related gene mutations.
RESULTS: A total of 17 patients (15.7 %) harbored IEI-associated mutations, including 4 cases with X-linked lymphoproliferative syndrome (XLP), 3 cases had mutations in tumor necrosis factor receptor superfamily 13B (TNFRSF13B), 2 cases with Activated p110 syndrome (APDS). Patients with IEI all had alteration of immunocompetence with decreased levels of immunoglobulin and lymphocyte subsets. Recurrent infection existed in 41.2 % of patients. The 18-month event-free survival (EFS) and the overall response rate (ORR) of patients with IEI are significantly lower than those without IEI (33.86% vs. 73.26 %, p = 0.011; 52.94% vs. 87.91 %, p = 0.002, respectively). In addition, patients with IEI had a higher progression disease (PD) rate of 23.5 % than those without IEI of 4.4 % (p = 0.006).
CONCLUSIONS: The present study demonstrated that IEI-associated lymphomas were much more common than originally appreciated in pediatric lymphomas, and those were insensitive to treatment and more likely to progress or relapse. The genomic analysis and a thorough review of the medical history of IEI can be used to distinguish them from pediatric lymphomas without IEI, which are beneficial for the early diagnosis and direct intervention.

UNASSIGNED: Patients with inborn errors of immunity (IEI) experience recurrent infections, autoimmunity, and malignancies. Owing to repeated medical procedures, the need for constant treatment and surveillance, and the unpredictable course of the disease, patients with IEI are prone to develop mental health disorders, including anxiety. In this study, we aimed to assess the prevalence and level of anxiety symptoms in adult Polish patients with IEI and explore the determinants of anxiety in this group of patients.
UNASSIGNED: Data from 105 Polish patients with IEI were collected via the hospital anxiety and depression scale (HADS), brief illness perception questionnaire (B-IPQ), illness cognition questionnaire (ICQ), Pittsburgh sleep quality index (PSQI), and a questionnaire on general health and demographic data. For statistical analyses of data, the normality of distribution of quantitative data was assessed, and internal consistency of tests was investigated using Cronbach\'s alpha coefficient; moreover, we performed the analysis of correlations and between-group differences, and path analysis to explore causal relationships. Significance was considered at p < 0.050.
UNASSIGNED: Thirty-eight (36.2%) patients had anxiety symptoms (HADS-A ≥ 8); 14 (13.3%) patients had severe anxiety (score ≥ 11), and 24 (22.9%) had moderate anxiety (score of 8-10). Patients with poor sleep quality, higher pain frequency, younger age, and no fixed income had higher anxiety scores than others. Emotional and cognitive representations of illness were positively correlated with anxiety levels. Intense anxiety was related to more negative illness perception, higher helplessness, lower illness acceptance, and lower perceived benefits.
UNASSIGNED: Anxiety is common in patients with IEI. However, results indicate that it is not related to a more severe course of IEI or several comorbidities, whereas, pain frequency and poor sleep quality were identified to be important clinical factors for anxiety. Because anxiety was related to negative illness perception, psychological therapy may apply to this group of patients.

This phase 3, open-label, multidose study (NCT04346108) evaluated the pharmacokinetics, safety, tolerability, and efficacy of immunoglobulin subcutaneous (human) 20% solution (Ig20Gly) administered weekly and every 2 weeks in Japanese patients with primary immunodeficiency diseases (PIDs). The study was conducted at eight study sites in Japan and enrolled patients aged ≥2 years with PIDs treated using a stable intravenous immunoglobulin dose for ≥3 months prior to the study. Patients received intravenous immunoglobulin every 3 or 4 weeks at pre-study dose (200-600 mg/kg) for 13 weeks (Epoch 1), subcutaneous Ig20Gly (50-200 mg/kg) once weekly for 24 weeks (Epoch 2), and Ig20Gly (100-400 mg/kg) every 2 weeks for 12 weeks (Epoch 3). The primary endpoint was serum total immunoglobulin G (IgG) trough levels during Epochs 2 and 3. Overall, 17 patients were enrolled (median [range] age: 24 [5-69] years; 59% male) and participated in Epochs 1 and 2; seven patients entered Epoch 3. Serum total IgG trough levels were maintained at >8 g/l: geometric means (95% confidence intervals) at the end of Epochs 2 and 3 were 8.56 (8.03-9.12) g/l and 8.39 (7.89-8.91) g/l, respectively. Related treatment-emergent adverse events were all mild in severity; the most common treatment-emergent adverse events (excluding infections) in Epochs 2 and 3 were injection site swelling (24%) and injection site erythema (18%). This is the first trial to demonstrate the efficacy and favourable safety profile of 20% subcutaneous immunoglobulin administered every 2 weeks in adult and paediatric Japanese patients with PIDs.

Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) 20% will allow reduced infusion volumes and frequency versus existing subcutaneous therapies such as fSCIG 10% and conventional subcutaneous immunoglobulin 20%, respectively. We assessed the tolerability, safety, and immunogenicity of warmed and unwarmed fSCIG 20%.
This phase 1, single-dose, open-label, three-arm study enrolled healthy adults aged 19-50 years (inclusive) at a single US center (NCT05059977). Post-screening, participants received a single fSCIG 20% dose comprising recombinant human hyaluronidase and varying doses of in-line warmed or unwarmed immunoglobulin G (IgG) during a 4-day treatment period in a sentinel and sequential dosing design (treatment arm 1, warmed IgG 20% 0.4 g/kg; treatment arm 2, warmed IgG 20% 1.0 g/kg; treatment arm 3, unwarmed IgG 20% 1.0 g/kg). Participants were followed for 12 (± 1) weeks post-infusion. The primary endpoint was tolerability (\"tolerable\" infusions were not interrupted, stopped, or reduced in rate owing to fSCIG 20%-related treatment-emergent adverse events (TEAEs)). Secondary endpoints included occurrence of TEAEs.
Overall, 24 participants were included, 8 per treatment arm (mean age 39.0 years, 54.2% men). All participants tolerated the infusions. All TEAEs were mild (107 events, in all participants), and all participants experienced fSCIG 20%-related (105 events) and local (102 events) TEAEs. Infusion site erythema and infusion site swelling were most frequently reported. No serious TEAEs occurred, and no participants discontinued the study owing to TEAEs.
fSCIG 20% was well-tolerated with a favorable safety profile in healthy adults. Future studies will evaluate fSCIG 20% in primary immunodeficiency diseases. Trial registration number (ClinicalTrials.gov): NCT05059977 (registered 28 September 2021).

BACKGROUND: The European Society for Immunodeficiencies recommends that all patients with inborn errors of immunity (IEI) without contraindications should receive SARS-CoV-2 vaccination. The aim of this study was to investigate the reasons that discourage IEI patients from receiving the recommended vaccination and to assess vaccination coverage among IEI patients in Latvia.
METHODS: In this multicenter mixed-methods study, the vaccination status of all patients with IEI within two tertiary centers in Latvia was reviewed using electronic health records. Semi-structured interviews were conducted with 16 IEI patients who did not undergo vaccination, and a thematic analysis was performed.
RESULTS: A total of 341 patients (49.3% female; median age 19.7 years (IQR:17)) were included in the quantitative part. The proportion of fully vaccinated individuals aged ≥ 12 years was 66.8%-70.9% with patients with selective IgA deficiency and 58.8% with other IEI (χ² = 14.12, p < 0.001). The proportion of fully vaccinated individuals aged 5-11 years was 11.1%. Age was associated with vaccination status: younger patients were found to have a significantly lower likelihood of receiving vaccination (U = 8585, p < 0.001). The five main themes identified were as follows: (1) fear and uncertainty; (2) risk and benefit assessment: COVID-19 vaccine-is it worth it? (3) external influences: the dark horse of the decision-making-people around us; (4) individuals against the system; and (5) beliefs about vaccination and COVID-19. Under-representation of certain IEI groups and recall bias are possible limitations of this study.
CONCLUSIONS: While most reasons for hesitancy were similar to those previously described in the general population, disease-specific concerns were also identified.

Common variable immunodeficiency (CVID) associated liver disease is an underrecognized and poorly studied non-infectious complication that lacks an established treatment. We describe a CVID patient with severe multiorgan complications, including non-cirrhotic portal hypertension secondary to nodular regenerative hyperplasia leading to diuretic-refractory ascites. Remarkably, treatment with rituximab, administered for concomitant immune thrombocytopenia, resulted in the complete and sustained resolution of portal hypertension and ascites. Our case, complemented with a literature review, suggests a beneficial effect of rituximab that warrants further research.