Case report: Virus-induced hemophagocytic lymphohistiocytosis in a patient with APECED.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive inborn error of immunity (IEI), which is accompanied by immune dysregulation. Hypoparathyroidism, adrenocortical failure and candidiasis are its typical manifestations. Here we report about recurrent COVID-19 in a 3-year-old boy with APECED, who developed retinopathy with macular atrophy and autoimmune hepatitis after the first episode of SARS-CoV-2 infection. Primary Epstein-Barr virus infection and a new episode of SARS-CoV-2 infection with COVID pneumonia triggered the development of severe hyperinflammation with signs of hemophagocytic lymphohistiocytosis (HLH): progressive cytopenia (thrombocytopenia, anemia, lymphopenia), hypoproteinemia, hypoalbuminemia, high levels of liver enzymes, hyperferritinemia, increased triglycerides levels; and coagulopathy with a low level of fibrinogen. Treatment with corticosteroids and intravenous immunoglobulins did not lead to a significant improvement. The progression of HLH and COVID-pneumonia resulted in a fatal outcome. The rarity and varied presentation of the HLH symptoms led to diagnostic difficulties and diagnosis delay. HLH should be suspected in a patient with immune dysregulation and impaired viral response. Treatment of infection-HLH is a major challenge due to the difficulties in balancing immunosuppression and management of underlying/triggering infection.

Newborn screening for severe combined immunodeficiency: The results of the first pilot TREC and KREC study in Ukraine with involving of 10,350 neonates.

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 (TlowB+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.

Evaluation of awareness about primary immunodeficiencies among physicians before and after implementation of the educational program: A longitudinal study.

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.

Novel compound heterozygous variants in NHLRC2 in a patient with FINCA syndrome.

Two variants in the ubiquitously expressed NHLRC2 gene have been reported to cause a lethal fibrotic cerebropulmonary disease termed fibrosis, neurodegeneration, and cerebral angiomatosis (FINCA) syndrome in three Finnish children. Our objective was to determine the genetic basis of disease in a new patient with clinical features of FINCA syndrome using whole-exome sequencing (WES) and confirmation by Sanger sequencing. The patient has one known and one novel variant in NHLRC2 (c.442T>G, p.D148Y and c.428C>A, p.H143P, respectively). p.H143P is extremely rare and is not present in the gnomAD database of >140,000 allele sequences from healthy humans. Both variants affect the highly conserved N-terminal thioredoxin (Trx)-like domain of NHLRC2 and are predicted to be damaging. We conclude that a compound heterozygous combination of a known and a novel variant in NHLRC2 causes FINCA syndrome in a 2-year-old Ukrainian patient, underscoring the importance of NHLRC2 as a central regulator of fibrosis.

The impact of combining educational program with the improving of infrastructure to diagnose on early detection of primary immunodeficiencies in children.

Early detection of primary immunodeficiency diseases (PID) is vital for adequate prevention and management of PID infectious complications. The objective of this study was to evaluate the impact of a model combining physician education and public awareness with the infrastructure to diagnose PID to improve its early detection in children. Three approaches were combined and the results were followed from February 2017 to February 2019 in Ternopil region, Ukraine: the education of primary care physicians and other specialists on early PID detection using workshops, trainings, and targeted publications; organization of public events and media appearances to raise PID awareness; performing immunological testing for patients with suspected PID. Among the 150 individuals that were screened, PID was diagnosed in 19 patients (12.7%). The majority of diagnosed PID cases were combined immunodeficiency with associated or syndromic features, followed by antibody deficiencies. Patients referred by the specialist doctors had the highest percentage of confirmed PID compared with those referred by primary care physicians (p = 0.0273) and risk group patients (p = 0.0447). Among warning signs in patients with PID, two or more pneumonias within 1 year occurred most often (26.3%), followed by failure of an infant to gain weight or grow normally (21.1%). Among other signs of PID, dysmorphic features and microcephaly were the most prevalent (31.6%). In conclusion, a program combining physician education and public awareness with infrastructure needed to diagnose primary immunodeficiency diseases is an effective tool for early PID diagnosis. Physician education was a more effective tool compared with rising public awareness.