This study demonstrates that similar RAG mutations can result in similar immunobiological effects but different clinical phenotypes, indicating that the level of residual recombinase activity is not the only determinant for clinical outcome. We postulate a model in which the type and moment of antigenic pressure affect the clinical phenotypes of these patients.

At the beginning of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, patients with inborn errors of immunity (IEI) appeared to be particularly vulnerable to a severe course of the disease. It quickly turned out that only some IEI groups are associated with a high risk of severe infection. However, data on the course of Coronavirus Disease 2019 (COVID-19) in patients with IEI are still insufficient, especially in children; hence, further analyses are required. The retrospective study included 155 unvaccinated people with IEI: 105 children and 50 adults (67.7% and 32.3%, respectively). Male patients dominated in the study group (94 people, 60.6%). At least two comorbidities were found in 50 patients (32.3%), significantly more often in adults (56% vs. 21%). Adult patients presented significantly more COVID-19 symptoms. Asymptomatic and mildly symptomatic course of COVID-19 was demonstrated in 74.8% of the entire group, significantly more often in children (88.6% vs. 46%). Moderate and severe courses dominated in adults (54% vs. 11.4%). Systemic antibiotic therapy was used the most frequently, especially in adults (60% vs. 14.3%). COVID-19-specific therapy was used almost exclusively in adults. In the whole group, complications occurred in 14.2% of patients, significantly more often in adults (30% vs. 6.7%). In the pediatric group, there were two cases (1.9%) of multisystem inflammatory syndrome in children. Deaths were reported only in the adult population and accounted for 3.9% of the entire study group. The death rate for all adults was 12%, 15.4% for adults diagnosed with common variable immunodeficiency, 12.5% for those with X-linked agammaglobulinemia, and 21.4% for patients with comorbidity. The results of our study imply that vaccinations against COVID-19 should be recommended both for children and adults with IEI. Postexposure prophylaxis and early antiviral and anti-SARS-CoV-2 antibody-based therapies should be considered in adults with IEI, especially in those with severe humoral immune deficiencies and comorbidity.

No abstract

Intravenous immunoglobulin (IVIG) therapy is commonly used to treat patients with primary antibody deficiency. This prospective, open-label, non-randomised, multicentre, phase III trial investigated the pharmacokinetics of a new 10% liquid IVIG product (panzyga®; Octapharma) in 51 patients aged 2-75 years with common variable immunodeficiency (n = 43) or X-linked agammaglobulinaemia (n = 8). Patients were treated with IVIG 10% every 3 (n = 21) or 4 weeks (n = 30) at a dose of 200-800 mg/kg for 12 months. Total immunoglobulin G (IgG) and subclass concentrations approximately doubled from pre- to 15 min post-infusion. The maximum concentration of total IgG (mean ± SD) was 21.82 ± 5.83 g/L in patients treated 3-weekly and 17.42 ± 3.34 g/L in patients treated 4-weekly. Median trough IgG concentrations were nearly constant over the course of the study, remaining between 11.0 and 12.2 g/L for patients on the 3-week schedule and between 8.10 and 8.65 g/L for patients on the 4-week schedule. The median terminal half-life of total IgG was 36.1 (range 18.5-65.9) days, with generally similar values for the IgG subclasses (26.7-38.0 days). Median half-lives for specific antibodies ranged between 21.3 and 51.2 days for anti-cytomegalovirus, anti-Haemophilus influenzae, anti-measles, anti-tetanus toxoid, anti-varicella zoster virus antibodies, and anti-Streptococcus pneumoniae subtype antibodies. Overall, IVIG 10% demonstrated pharmacokinetic properties similar to those of other commercial IVIG 10% preparations and 3- or 4-weekly administration achieved sufficient concentrations of IgG, IgG subclasses, and specific antibodies, exceeding the recommended level needed to effectively prevent serious bacterial infections.