Neuroinflammation and Oxidative Stress in Individuals Affected by DiGeorge Syndrome.

DiGeorge syndrome (DGS) is a rare genetic disease caused by microdeletions of the 22q11.2 region (DGS1). A haploinsufficiency at 10p level has been proposed also as a DGS cause (DGS2). Clinical manifestations are variable. The most frequent features are thymic hypoplasia or aplasia with consequent immune deficiency, cardiac malformations, hypoparathyroidism, facial and palatine abnormalities, variable degrees of cognitive impairment and psychiatric disorders. The specific aim of this descriptive report is to discuss the correlation between oxidative stress and neuroinflammation in DGS patients with microdeletions of the 22q11.2 region. The deleted chromosomic region maps various genes involved in mitochondrial metabolisms, such as DGCR8 and TXNRD2, that could lead to reactive oxygen species (ROS) increased production and antioxidant depletion. Furthermore, increased levels of ROS in mitochondria would lead to the destruction of the projection neurons in the cerebral cortex with consequent neurocognitive impairment. Finally, the increase in modified protein belonging to the family of sulfoxide compounds and hexoses, acting as inhibitors of the IV and V mitochondria complex, could result in direct ROS overproduction. Neuroinflammation in DGS individuals could be directly related to the development of the syndrome's characteristic psychiatric and cognitive disorders. In patients with psychotic disorders, the most frequent psychiatric manifestation in DGS, Th-17, Th-1 and Th-2 cells are increased with consequent elevation of proinflammatory cytokine IL-6 and IL1ß. In patients with anxiety disorders, both CD3 and CD4 are increased. Some patients with autism spectrum disorders (ASDs) have an augmented level of proinflammatory cytokines IL-12, IL-6 and IL-1ß, while IFNγ and the anti-inflammatory cytokine IL-10 seem to be reduced. Other data proposed that altered synaptic plasticity could be directly involved in DGS cognitive disorders. In conclusion, the use of antioxidants for restoring mitochondrial functionality in DGS could be a useful tool to protect cortical connectivity and cognitive behavior.

Severe Acute Respiratory Syndrome Coronavirus 2 Monoclonal Antibody Combination Therapy in Patients With Coronavirus Disease 2019 and Primary Antibody Deficiency.

BACKGROUND: Previous reports highlighted the efficacy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific monoclonal antibodies (mAbs) against coronavirus disease 2019. METHODS: We conducted a prospective study on the clinical outcome and antiviral effects of mAbs added to standard of care therapy in SARS-CoV-2-infected patients with primary antibody defects. RESULTS: Median time of SARS-CoV-2 quantitative polymerase chain reaction (qPCR) positivity was shorter in 8 patients treated with mAbs (22 days) than in 10 patients treated with standard of care therapy only (37 days, P=.026). Median time of SARS-CoV-2 qPCR positivity from mAb administration was 10 days. CONCLUSIONS: The SARS-CoV-2 mAbs treatment was effective and well tolerated in patients with primary antibody defects.

COVID-19 infection and vaccination in immunodeficiency.

During the last 2 years and a half, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide, causing about 6 million deaths. Clinical manifestations are highly variable, ranging from entirely asymptomatic infection to multiorgan failure and death. The outcome in immunocompromised patients is still a matter of debate, and so are the optimal strategies to prevent or treat the infection in these high-risk populations.

Selective IgA Deficiency and Allergy: A Fresh Look to an Old Story.

Selective IgA deficiency (SIgAD) is the most common human primary immune deficiency (PID). It is classified as a humoral PID characterized by isolated deficiency of IgA (less than 7 mg/dL but normal serum IgG and IgM) in subjects greater than 4 years of age. Intrinsic defects in the maturation of B cells and a perturbation of Th cells and/or cytokine signals have been hypothesized to contribute to SIgAD pathogenesis. The genetic basis of IgA deficiency remains to be clarified. Patients with SIgAD can be either asymptomatic or symptomatic with clinical manifestations including allergy, autoimmunity and recurrent infections mainly of the respiratory and gastrointestinal tract. Studies analyzing allergy on SIgAD patients showed prevalence up to 84%, supporting in most cases the relationship between sIgAD and allergic disease. However, the prevalence of allergic disorders may be influenced by various factors. Thus, the question of whether allergy is more common in SIgAD patients compared to healthy subjects remains to be defined. Different hypotheses support an increased susceptibility to allergy in subjects with SIgAD. Recurrent infections due to loss of secretory IgA might have a role in the pathogenesis of allergy, and vice versa. Perturbation of microbiota also plays a role. The aim of this review is to examine the association between SIgAD and atopic disease and to update readers on advances over time at this important interface between allergy and SIgAD.

SARS-CoV-2 Vaccine Induced Atypical Immune Responses in Antibody Defects: Everybody Does their Best.

BACKGROUND: Data on immune responses to SARS-CoV-2 in patients with Primary Antibody Deficiencies (PAD) are limited to infected patients and to heterogeneous cohorts after immunization. METHODS: Forty-one patients with Common Variable Immune Deficiencies (CVID), six patients with X-linked Agammaglobulinemia (XLA), and 28 healthy age-matched controls (HD) were analyzed for anti-Spike and anti-receptor binding domain (RBD) antibody production, generation of Spike-specific memory B-cells, and Spike-specific T-cells before vaccination and one week after the second dose of BNT162b2 vaccine. RESULTS: The vaccine induced Spike-specific IgG and IgA antibody responses in all HD and in 20% of SARS-CoV-2 naive CVID patients. Anti-Spike IgG were detectable before vaccination in 4 out 7 CVID previously infected with SARS-CoV-2 and were boosted in six out of seven patients by the subsequent immunization raising higher levels than patients naïve to infection. While HD generated Spike-specific memory B-cells, and RBD-specific B-cells, CVID generated Spike-specific atypical B-cells, while RBD-specific B-cells were undetectable in all patients, indicating the incapability to generate this new specificity. Specific T-cell responses were evident in all HD and defective in 30% of CVID. All but one patient with XLA responded by specific T-cell only. CONCLUSION: In PAD patients, early atypical immune responses after BNT162b2 immunization occurred, possibly by extra-follicular or incomplete germinal center reactions. If these responses to vaccination might result in a partial protection from infection or reinfection is now unknown. Our data suggests that SARS-CoV-2 infection more effectively primes the immune response than the immunization alone, possibly suggesting the need for a third vaccine dose for patients not previously infected.

Long-term follow-up of 168 patients with X-linked agammaglobulinemia reveals increased morbidity and mortality.

BACKGROUND: X-linked agammaglobulinemia (XLA) is the prototype of primary humoral immunodeficiencies. Long-term follow-up studies regarding disease-related complications and outcome are scarce. OBJECTIVE: Our aim was to describe the natural history of XLA. METHODS: A nationwide multicenter study based on the Italian Primary Immunodeficiency Network registry was established in 2000 in Italy. Affected patients were enrolled by documenting centers, and the patients' laboratory, clinical, and imaging data were recorded on an annual base. RESULTS: Data on the patients (N = 168) were derived from a cumulative follow-up of 1370 patient-years, with a mean follow-up of 8.35 years per patient. The mean age at diagnosis decreased after establishment of the Italian Primary Immunodeficiency Network registry (84 months before vs 23 months after). Respiratory, skin, and gastrointestinal manifestations were the most frequent clinical symptoms at diagnosis and during long-term follow-up. Regular immunoglobulin replacement treatment reduced the incidence of invasive infections. Affected patients developed chronic lung disease over time (47% after 40 years of follow-up) in the presence of chronic sinusitis (84%). Malignancies were documented in a minority of cases (3.7%). Overall survival for affected patients was significantly reduced when compared with that for the healthy male Italian population, and it further deteriorated in the presence of chronic lung disease. CONCLUSIONS: This is the first detailed long-term follow-up study for patients with XLA, revealing that although immunoglobulin replacement treatment reduces the incidence of invasive infections, it does not appear to influence the development of chronic lung disease. The overall survival of affected patients is reduced. Further studies are warranted to improve patients' clinical management and increase awareness among physicians.

Health-Related Quality of Life and Emotional Difficulties in Chronic Granulomatous Disease: Data on Adult and Pediatric Patients from Italian Network for Primary Immunodeficiency (IPINet).

Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by life-threatening infections, inflammation, and autoimmunity with an impact on health-related quality of life (HRQoL). Few data are available for children, whereas no study has been conducted in adults. Here, we investigated HRQoL and emotional functioning of 19 children and 28 adults enrolled in Italian registry for CGD. PEDsQL and SDQ were used for children and their caregivers, and adults completed the SF-12 questionnaire. Mean scores were compared with norms and with patients affected by chronic diseases. Comparisons were made for CGD patients who underwent or not hematopoietic stem cell transplantation (HSCT). When compared with norms, CGD children exhibited higher difficulties in social/school areas, peer relationship, and conduct/emotional problems (< 5 years of age), as scored by proxies. Differently, CGD adults reported higher difficulties both in mental and physical area than norms. Only for children, clinical status had a damaging effect on psychosocial and school dimensions, whereas age had a negative impact on social areas. No significant difference was observed between patients treated or not with HSCT. When compared with patients affected by chronic diseases, CGD children and adults both displayed fewer physical disabilities. Differently, in mental scale adults scored lower than those with rheumatology diseases and had similar impairment in comparison with patients with diabetes mellitus and cancer. This study emphasized the impact of CGD on HRQoL since infancy and its decline in adulthood, with emotional difficulties occurring early. HRQoL impairment should be considered in clinical picture of CGD and pro-actively assessed and managed by clinicians.

Double-blind, placebo-controlled, randomized trial on low-dose azithromycin prophylaxis in patients with primary antibody deficiencies.

BACKGROUND: Lacking protective antibodies, patients with primary antibody deficiencies (PADs) experience frequent respiratory tract infections, leading to chronic pulmonary damage. Macrolide prophylaxis has proved effective in patients with chronic respiratory diseases. OBJECTIVE: We aimed to test the efficacy and safety of orally administered low-dose azithromycin prophylaxis in patients with PADs. METHODS: We designed a 3-year, double-blind, placebo-controlled, randomized clinical trial to test whether oral azithromycin (250 mg administered once daily 3 times a week for 2 years) would reduce respiratory exacerbations in patients with PADs and chronic infection-related pulmonary diseases. The primary end point was the number of annual respiratory exacerbations. Secondary end points included time to first exacerbation, additional antibiotic courses, number of hospitalizations, and safety. RESULTS: Eighty-nine patients received azithromycin (n = 44) or placebo (n = 45). The number of exacerbations was 3.6 (95% CI, 2.5-4.7) per patient-year in the azithromycin arm and 5.2 (95% CI, 4.1-6.4) per patient-year in the placebo arm (P = .02). In the azithromycin group the hazard risk for having an acute exacerbation was 0.5 (95% CI, 0.3-0.9; P = .03), and the hazard risk for hospitalization was 0.5 (95% CI, 0.2-1.1; P = .04). The rate of additional antibiotic treatment per patient-year was 2.3 (95% CI, 2.1-3.4) in the intervention group and 3.6 (95% CI, 2.9-4.3) in the placebo group (P = .004). Haemophilus influenzae and Streptococcus pneumoniae were the prevalent isolates, and they were not susceptible to macrolides in 25% of patients of both arms. Azithromycin's safety profile was comparable with that of placebo. CONCLUSION: The study reached the main outcome centered on the reduction of exacerbation episodes per patient-year, with a consequent reduction in additional courses of antibiotics and risk of hospitalization.

Health-Related Quality of Life in Patients with CVID Under Different Schedules of Immunoglobulin Administration: Prospective Multicenter Study.

OBJECTIVE: We assessed the health-related quality of life (HRQoL) in CVID adults receiving different schedules of immunoglobulin replacement therapy (IgRT) by intravenous (IVIG), subcutaneous (SCIG), and facilitated (fSCIG) preparations. For these patients, IgRT schedule was chosen after a period focused on identifying the most suitable individual option. METHODS: Three hundred twenty-seven participants were enrolled in a prospective, observational, 18-month study. Participants received IgRT for at least 2 years. The first 6 months were devoted to the educational process during which the choices related to IgRT were regularly re-assessed, and the shift to alternative regimen was permitted. During the following 12 months, clinical data were prospectively collected, and only patients who did not further modify their IgRT schedule were included in the analysis of HRQoL measured by CVID_QoL, a specific instrument, and by GHQ-12, a tool to assess minor psychiatric nonpsychotic disorders. RESULTS: Three hundred four patients were included in the analysis. CVID_QoL global score and its dimensions (emotional functioning, relational functioning, gastrointestinal symptoms) were similar in IVIG, SCIG, and fSCIG recipients. Patients receiving IgRT by different routes of administration reported similar capacity to make long-term plans, discomfort due to therapy, and concern to run out of medications. Multivariate analysis revealed the GHQ-12 status, but not the IgRT mode of administration, as the major factor impacting on treatment-related QoL items, and a significant impact of age on discomfort related to IgRT. CONCLUSIONS: IgRT schedules do not impact the HRQoL in CVID if the treatment is established after an extensive educational period focused on individualizing the best therapeutic regimen.

The high mortality of patients with common variable immunodeficiency and small bowel villous atrophy.

OBJECTIVES: Common variable immunodeficiency (CVID) is a primary humoral immunodeficiency characterised by reduced serum levels of immunoglobulins, recurrent infections, autoimmune phenomena and lymphoproliferative disorders. Gastrointestinal symptoms are very common in these patients and a coeliac-like villous atrophy was described in some of them. Since mortality in CVID is much higher than in the general population, our aim was to evaluate mortality rates and clinical predictors of survival in patients with both CVID and duodenal villous atrophy. PATIENTS AND METHODS: Sex, date of diagnosis of villous atrophy, HLA genomic typing, date of death/last follow-up, type of complication were retrospectively collected from medical files. Univariate analysis for each predictor was conducted and Kaplan-Meier curves were generated to evaluate survival. RESULTS: Twenty-three patients were enrolled (9 females, mean age at diagnosis of villous atrophy 38 ± 13 years) and 8 of them died after a median time of 96 months (25th-75th 60-120 months) corresponding to a mortality rate of 3.9 per 100 person-years (95% CI 1.9-7.7). Mortality was higher in men compared to women (60 vs. 11/1000 person-years), although not statistically significant. Causes of death included onco-haematological disorders and infections. CONCLUSIONS: Although based on a small cohort, our results confirm that patients with CVID and villous atrophy are burdened by a very high mortality mainly due to onco-immunological disorders and infections. Strict follow-up is required in these patients.

Hyper-IgE in the allergy clinic--when is it primary immunodeficiency?

The 2017 International Union of Immunological Societies (IUIS) classification recognizes 3 hyper-IgE syndromes (HIES), including the prototypic Job's syndrome (autosomal dominant STAT3-loss of function) and autosomal recessive PGM3 and SPINK5 syndromes. Early diagnosis of PID can direct life-saving or transformational interventions; however, it remains challenging owing to the rarity of these conditions. This can result in diagnostic delay and worsen prognosis. Within increasing access to "clinical-exome" testing, clinicians need to be aware of the implication and rationale for genetic testing, including the benefits and limitations of current therapies. Extreme elevation of serum IgE has been associated with a growing number of PID syndromes including the novel CARD11 and ZNF341 deficiencies. Variable elevations in IgE are associated with defects in innate, humoral, cellular and combined immunodeficiency syndromes. Barrier compromise can closely phenocopy these conditions. The aim of this article was to update readers on recent developments at this important interface between allergy and immunodeficiency, highlighting key clinical scenarios which should draw attention to possible immunodeficiency associated with extreme elevation of IgE, and outline initial laboratory assessment and management.

Lung magnetic resonance imaging with diffusion weighted imaging provides regional structural as well as functional information without radiation exposure in primary antibody deficiencies.

PURPOSE: Primary antibody deficiency patients suffer from infectious and non-infectious pulmonary complications leading over time to chronic lung disease. The complexity of this pulmonary involvement poses significant challenge in differential diagnosis in patients with long life disease and increased radio sensitivity. We planned to verify the utility of chest Magnetic Resolution Imaging with Diffusion-Weighted Imaging as a radiation free technique. METHODS: Prospective evaluation of 18 patients with Common Variable Immunodeficiency and X-linked Agammaglobulinemia. On the same day, patients underwent Magnetic Resonance Imaging with Diffusion Weighted Imaging sequences, High Resolution Computerized Tomography and Pulmonary Function Tests, including diffusing capacity factor for carbon monoxide. Images were scored using a modified version of the Bhalla scoring system. RESULTS: Magnetic Resonance Imaging was non-inferior to High Resolution Computerized Tomography in the capacity to identify bronchial and parenchymal abnormalities. HRCT had a higher capacity to identify peripheral airways abnormalities, defined as an involvement of bronchial generation up to the fifth and distal (scores 2-3). Bronchial scores negatively related to pulmonary function tests. One third of consolidations and nodules had Diffusion Weighted Imaging restrictions associated with systemic granulomatous disease and systemic lymphadenopathy. Lung Magnetic Resolution Imaging detected an improvement of bronchial and parenchymal abnormalities, in recently diagnosed patients soon after starting Ig replacement. CONCLUSIONS: Magnetic Resonance Imaging with Diffusion Weighted Imaging was a reliable technique to detect lung alterations in patients with Primary Antibody Deficiencies.

Hemolysis in patients with antibody deficiencies on immunoglobulin replacement treatment.

BACKGROUND: Immunoglobulin (Ig)G replacement with intravenous or subcutaneous immunoglobulins is a lifelong substitutive therapy in patients with primary antibody deficiencies (PADs). Hemolysis after immunoglobulin therapy was described in patients receiving high immunoglobulin dosages. The issue of hemolysis after immunoglobulin administration at replacement doses has been considered of little clinical significance. STUDY DESIGN AND METHODS: This was a single-center observational study over a 2-year period on immunoglobulin-induced hemolysis in a cohort of 162 patients with PADs treated with immunoglobulin administered at replacement dosages. RESULTS: Six patients had signs and symptoms of immunoglobulin-induced hemolysis. Two additional asymptomatic patients were identified by a short-term study run on 16 randomly selected asymptomatic patients. Alloantibodies eluted from patients' red blood cells (RBCs) had anti-A and Rh specificities (anti-D and anti-C). The immunoglobulins contained alloantibodies with the same specificities of the antibodies eluted from patients' RBCs. CONCLUSION: Hemolysis occurred in patients receiving immunoglobulin at replacement dosages. Polyvalent immunoglobulin preparations contained multiple clinically significant antibodies that could have unexpected hemolytic consequences, as anti-C whose research and titration are not required by the European Pharmacopoeia. The issue of hemolysis in long-term recipients of immunoglobulin treatment administered at replacement dosages should be more widely recognized.

Adequate patient's outcome achieved with short immunoglobulin replacement intervals in severe antibody deficiencies.

PURPOSE: The optimal immune globulin replacement dosages required over time to minimize infection risks in patients with Primary Antibody Deficiencies are not definitely established. As with many interventions, there may be specific subgroups of patients who are more likely to benefit from treatment with higher or lower dosages. The aim of the study was to verify the efficacy of a rationale for individualized immune globulin utilization and to elucidate the effects of care on patient outcome. METHODS: Single centre interventional study on 108 patients with Primary Antibody Deficiencies. The objective was to determine for each patient the best interval between immune globulins administration in order to: • Keep IgG trough levels >500 mg/dL, • Minimize of major infections (pneumonias and infections requiring hospitalization), • Minimize of adverse events (AE). RESULTS: Ninthly eight per cent of patients achieved the objective of the study. Patients who had low switched memory B cells and low IgA serum levels and/or are affected by bronchiectasis and/or enteropathy and/or continued to experience adverse events despite pre-medications, achieved the study objective by shortening the administration intervals to 2-weeks or to 1-week without the need to increase the monthly cumulative immunoglobulin dosage and its relative cost. The adverse events were reduced by administrating low Ig dosages in a single setting. Patients without risk factors achieved the study objective with immune globulin replacement administered with the widely used interval of 3 or 4 weeks. CONCLUSIONS: The exact timing and optimal immunoglobulin prophylaxis regimen might be tailored according to clinical and immunological markers.

Oropharyngeal microbial ecosystem perturbations influence the risk for acute respiratory infections in common variable immunodeficiency.

Background: The respiratory tract microbiome is essential for human health and well-being and is determined by genetic, lifestyle, and environmental factors. Patients with Common Variable Immunodeficiency (CVID) suffer from respiratory and intestinal tract infections, leading to chronic diseases and increased mortality rates. While CVID patients' gut microbiota have been analyzed, data on the respiratory microbiome ecosystem are limited. Objective: This study aims to analyze the bacterial composition of the oropharynx of adults with CVID and its link with clinical and immunological features and risk for respiratory acute infections. Methods: Oropharyngeal samples from 72 CVID adults and 26 controls were collected in a 12-month prospective study. The samples were analyzed by metagenomic bacterial 16S ribosomal RNA sequencing and processed using the Quantitative Insights Into Microbial Ecology (QIME) pipeline. Differentially abundant species were identified and used to build a dysbiosis index. A machine learning model trained on microbial abundance data was used to test the power of microbiome alterations to distinguish between healthy individuals and CVID patients. Results: Compared to controls, the oropharyngeal microbiome of CVID patients showed lower alpha- and beta-diversity, with a relatively increased abundance of the order Lactobacillales, including the family Streptococcaceae. Intra-CVID analysis identified age >45 years, COPD, lack of IgA, and low residual IgM as associated with a reduced alpha diversity. Expansion of Haemophilus and Streptococcus genera was observed in patients with undetectable IgA and COPD, independent from recent antibiotic use. Patients receiving azithromycin as antibiotic prophylaxis had a higher dysbiosis score. Expansion of Haemophilus and Anoxybacillus was associated with acute respiratory infections within six months. Conclusions: CVID patients showed a perturbed oropharynx microbiota enriched with potentially pathogenic bacteria and decreased protective species. Low residual levels of IgA/IgM, chronic lung damage, anti antibiotic prophylaxis contributed to respiratory dysbiosis.

Salivary α-Synuclein as a Candidate Biomarker of Parkinsonism in 22q11.2 Deletion Syndrome.

BACKGROUND: 22q11.2 deletion syndrome (22q11.2DS) has been linked to an increased risk of early-onset Parkinson's disease. However, the pathophysiological mechanisms underlying parkinsonism remain poorly understood. OBJECTIVE: The objective is to investigate salivary total α-synuclein levels in 22q11.2DS patients with and without parkinsonian motor signs. METHODS: This cross-sectional study included 10 patients with 22q11.2DS with parkinsonism (Park+), ten 22q11.2DS patients without parkinsonism (Park-), and 10 age and sex-comparable healthy subjects (HS). Salivary and serum α-synuclein levels were measured using enzyme-linked immunosorbent assay. RESULTS: Salivary total α-synuclein concentration was significantly lower in Park (+) patients than in Park (-) patients and HS (P = 0.007). In addition, salivary α-synuclein showed good accuracy in discriminating Park (+) from Park (-) patients (area under the curve = 0.86) and correlated with motor severity and cognitive impairment. CONCLUSION: This exploratory study suggests that the parkinsonian phenotype of 22q11.2DS is associated with a reduced concentration of monomeric α-synuclein in biological fluids.

Efficacy and safety of clozapine in treatment-resistant psychotic patients with DiGeorge syndrome (22q11.2 deletion syndrome): a case series.

Neuropsychiatric disorders are common manifestations in 22q11.2 deletion syndrome (22q11.2DS-DiGeorge Syndrome). Although many patients with 22q11.2DS receive antipsychotic treatment for psychotic disorders, little is known about the safety and tolerability of antipsychotics in 22q11.2DS and resistant psychosis. The aim of this case series is to describe the effectiveness as well as safety and tolerability profile coming from the real-world observation of three clinical cases affected by 22q11.2DS and treatment-resistant psychosis. We administered the following tests: the Columbia Suicide Severity Rating Scale, the Hamilton Rating Scale for Anxiety, the Positive and Negative Severity Scale, the Clinical Global Impression-Severity Scale, the Yale-Brown Obsessive-Compulsive Scale, the Beck Depression Inventory and the Beck Hopelessness Scale. All these questionnaires were administered at the first visit (T0), and then 3 (T1) 6 (T2) and 12 months after (T3). We observed a clinical improvement that remained stable at 12 months. Furthermore, in our patients, the clinical effectiveness was achieved with a very low dose of clozapine (<150 mg/day) concerning the standard dose used in idiopathic schizophrenia (>300 mg/day to 600 mg/day).

COVID-19 Severity, Cardiological Outcome, and Immunogenicity of mRNA Vaccine on Adult Patients With 22q11.2 DS.

BACKGROUND: The contemporaneous presence of immune defects and heart diseases in patients with 22q11.2 deletion syndrome (22q11.3DS) might represent risk factors for severe coronavirus 2019 disease (COVID-19). OBJECTIVE: To analyze severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outcome in 22q11.2DS patients and immunogenicity of different doses of mRNA SARS-CoV-2 vaccine. METHODS: Longitudinal observational study on SARS-CoV-2 outcome in 60 adults with 22q11.2DS (March 2020-June 2022). Anti-Spike, and anti-receptor binding domain (RBD) antibody responses, generation of Spike-specific memory B cells (MBCs) and Spike-specific T cells at different time points before and after the mRNA BNT162b2 vaccination were evaluated in 16 22q11.2DS patients. RESULTS: We recorded a 95% rate of vaccination, with almost all patients being immunized with the booster dose. Twenty-one patients had SARS-CoV-2 infection. Three patients were infected before vaccine availability, 6 after receiving 2 doses of vaccine, and 12 after one booster dose. The SARS-CoV-2- infection had a mild course, except in one unvaccinated patient with several comorbidities who died from acute respiratory distress syndrome (fatality rate 5%). Infected patients had more frequently moderate/severe intellectual disability, lymphopenia, and lower CD4+ count. Despite major congenital heart diseases, COVID-19 did not impact cardiological conditions. The BNT162b2 vaccine induced S1-immunoglobulin G (IgG) responses, low serum S1-IgA, and slightly impaired specific MBCs response. Specific T-cell responses observed were related to lymphocytes and CD4+ T cell counts. CONCLUSIONS: The SARS-CoV-2 infection had a mild course in most patients with 22q11.2DS, even in patients with major cardiovascular diseases. Immunization induced Spike-specific IgG responses and generated specific MBCs and memory T cells. The weaker memory responses in patients with lymphopenia suggested the need for additional doses.