Life-threatening “breakthrough” cases of critical COVID-19 are attributed to poor or waning antibody (Ab) response to SARS-CoV-2 vaccines in individuals already at risk. Preexisting auto-Abs neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; their contribution to hypoxemic breakthrough cases in vaccinated people is unknown. We studied a cohort of 48 individuals (aged 20 to 86 years) who received two doses of a messenger RNA (mRNA) vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Ab levels to the vaccine, neutralization of the virus, and auto-Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal Ab response to the vaccine. Among them, 10 (24%) had auto-Abs neutralizing type I IFNs (aged 43 to 86 years). Eight of these 10 patients had auto-Abs neutralizing both IFN-α2 and IFN-ω, whereas two neutralized IFN-ω only. No patient neutralized IFN-β. Seven neutralized type I IFNs at 10 ng/ml and three at 100 pg/ml only. Seven patients neutralized SARS-CoV-2 D614G and Delta efficiently, whereas one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only type I IFNs at 100 pg/ml neutralized both D614G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating Abs capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a notable proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population.

Severe combined immunodeficiency (SCID) is a group of inborn errors of immunity (IEI) characterized by severe T- and/or B-lymphopenia. At birth, there are usually no clinical signs of the disease, but in the first year of life, often in the first months the disease manifests with severe infections. Timely diagnosis and treatment play a crucial role in patient survival. In Ukraine, the expansion of hemostatic stem cell transplantation and the development of a registry of bone marrow donors in the last few years have created opportunities for early correction of IEI and improving the quality and life expectancy of children with SCID. For the first time in Ukraine, we initiated a pilot study on newborn screening for severe combined immunodeficiency and T-cell lymphopenia by determining T cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs). The analysis of TREC and KREC was performed by real-time polymerase chain reaction (RT-PCR) followed by analysis of melting curves in neonatal dry blood spots (DBS). The DBS samples were collected between May 2020 and January 2022. In total, 10,350 newborns were screened. Sixty-five blood DNA samples were used for control: 25 from patients with ataxia-telangiectasia, 37 - from patients with Nijmegen breakage syndrome, 1 – with X-linked agammaglobulinemia, 2 – with SCID (JAK3 deficiency and DCLRE1C deficiency). Retest from the first DBS was provided in 5.8% of patients. New sample test was needed in 73 (0.7%) of newborns. Referral to confirm or rule out the diagnosis was used in 3 cases, including one urgent abnormal value. CID (T^lowB+NK+) was confirmed in a patient with the urgent abnormal value. The results of a pilot study in Ukraine are compared to other studies (the referral rate 1: 3,450). Approbation of the method on DNA samples of children with ataxia-telangiectasia and Nijmegen syndrome showed a high sensitivity of TRECs (a total of 95.2% with cut-off 2000 copies per 10⁶ cells) for the detection of these diseases. Thus, the tested method has shown its effectiveness for the detection of T- and B-lymphopenia and can be used for implementation of newborn screening for SCID in Ukraine.

The aim of the study was to determine the frequency and the course of COVID-19 infection in children with juvenile idiopathic arthritis (JIA). The study involved 51 patients with JIA aged 2 to 18 years. Evidence of COVID-19 was found in 10 (19.6%) patients with JIA. COVID-19 infection occurred more often in patients with systemic arthritis (OR = 6.1667, 95% CI: 1.2053–31.5511, p = 0.0289). The course of COVID-19 infection in patients with JIA was generally similar to the course in the pediatric population, despite immunosuppressive therapy. In 3 out of 10 patients the infection caused an exacerbation of JIA, which required therapy escalation.

22q11.2 deletion syndrome (22q11.2 DS) is a disorder that has multiple symptoms and affects various organs and systems. Despite the great variability of clinical manifestations, common 22q11.2 DS includes congenital heart defect, immunodeficiency, characteristic facial features, palatal defects, developmental and/or learning disabilities, and hypocalcaemia. We present the cases of three patients with 22q11.2 DS that we have observed. Heart defects were revealed in all cases, and tetralogy of Fallot in one of them. Immune system disorders in these cases were highly variable and did not correlate with aplasia or hypoplasia of the thymus. Cleft palate was diagnosed only in one case. Characteristic facial features were presented in all cases but they were not significant and varied from subtle to mild. Developmental disability was presented by motor delays in two cases. Hypocalcaemia was revealed in one patient, and seizures were absent. Only one case completely fit CATCH-22 syndrome (cardiac defects, abnormal facies, thymic hypoplasia, cleft palate, and hypocalcaemia caused by22q11.2 deletion). The other cases had three out of the five main features, with some other, less significant signs also presented. In some cases, even just a few signs should be the reason for further examination to exclude 22q11.2 deletion syndrome. Currently, immunological disorders are not a significant determinant in the diagnosis of this syndrome, and timely correction of heart defects can reduce the number of recurrent respiratory infections. A multidisciplinary approach to the management of these patients and providing timely, complex medical care will prevent serious complications.

Increasing physicians’ awareness is one of the main ways to improve early diagnosis of rare diseases. A survey among physicians of different specialties to evaluate the knowledge about primary immunodeficiencies (PID) was conducted in 2016 and in 2019 –before and after the implementation of an educational program. We compare responses from 82 doctors who participated in the 2016 survey, and 67 doctors who have taken part in the survey in 2019: pediatricians, general practitioners / family physicians and physicians of pediatric sub specialties. The percentage of correct answers to all survey questions after the implementation of the educational program has significantly increased (79.0% in 2019 versus 58.3% in 2016, P<0.0001). This increase in the percentage of correct answers was noted among the surveyed doctors of all specialties. Particular progress was found among pediatricians, who have achieved more than 80% of correct answers. In 2019 the doctors demonstrated better knowledge on the warning signs of PID and specific features of Nijmegen breakage syndrome, DiGeorge syndrome and ataxia-telangiectasia syndrome. Thus, the implementation of an educational program improved physicians’ awareness of PIDs, and will contribute to early detection of PIDs and their medical care.

Introduction Primary immunodeficiencies (PID) are genetic defects of the immune system that result in chronic, serious, and often life-threatening infections if they are not diagnosed and treated. Worldwide, from 70 to 90% of PID sufferers remain undiagnosed because of poor awareness. Early...