Evaluation of pediatric patients with suspected polyethylene glycol and polysorbate allergy before mRNA SARS-CoV2 vaccination.

mRNA vaccines, particularly, have been associated with an increased risk of allergic reactions and rarely anaphylaxis. Although rare, vaccine reactions can cause significant anxiety and fear in the population, leading to indecision and vaccine refusal. This study aimed to retrospectively evaluate the role of polyethylene glycol (PEG) sensitivity in vaccination decision-making in pediatric patients at high risk of allergy or with suspected allergic reactions to the first dose of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccine. Seventeen enrolled patients were found to have decreased readiness to receive the Coronavirus Disease 2019 (COVID-19) vaccine after developing hypersensitivity to multiple and/or injectable drugs. Skin testing was performed. A basophil activation test with PEG-2000 and 4000 was performed on three patients who were ineligible for skin prick tests. Nine patients with negative tests received the vaccine without complications. One patient had urticarial angioedema despite negative tests. Three patients with positive tests did not agree to desensitization with the mRNA vaccine, and one of them was vaccinated with the inactivated COVID-19 vaccine. Four patients recurred despite negative tests. The general recommendation for patients describing severe reactions to drugs, foods, and allergens, such as toxins that do not contain the adjuvants of the SARS-CoV-2 vaccines, is to be routinely vaccinated with safety precautions. Excipients such as PEG and polysorbate-80 used in COVID-19 vaccines could be potential allergens, but this hypothesis is unclear. The predictive values of these adjuvants for skin testing and in vitro testing are controversial. Further research is needed on the hypersensitivity reactions of adjuvants, the predictive values of skin tests, and etiopathogenesis.

Altered immune response in organic acidemia.

BACKGROUND: Most patients with organic acidemia suffer from recurrent infections. Although neutropenia has been reported in multiple studies, other components of the immune system have not been evaluated thoroughly. This study was conducted to assess the immune status of patients with organic acidemia (OA). METHODS: Thirty-three patients with OA who were followed up in Istanbul University-Cerrahpasa, Cerrahpasa School of Medicine, Nutrition and Metabolism Department and a total of 32 age- and sex-matched healthy controls were enrolled to the study. The demographic and clinical data were recorded retrospectively from patient files. Complete blood counts, immunoglobulins, and lymphocyte immunophenotyping were recorded prospectively in a symptom- (infection-) free period. RESULTS: Of the 33 patients enrolled to the study, 21 (88%) were diagnosed with methylmalonic acidemia, 10 (33%) with propionic acidemia, and two (6.6%) with isovaleric acidemia. The mean age of the patients with OA and healthy subjects were 5.89 ± 4.11 years and 5.34 ± 4.36, respectively (P = 0.602). Twenty-nine (88%) of the patients had experienced frequent hospital admission, 13 (39%) were admitted to pediatric intensive care unit, and 18 (55%) suffered from sepsis. Naïve helper T cells and recent thymic emigrants were significantly lower in OAs (P < 0.001). Various defects in humoral immunity have also been documented including memory B cells and immunoglobulins. CONCLUSIONS: Patients with OAs may show adaptive immune defects rendering them susceptible to infections. Metabolic reprogramming based on nutritional modifications may be a promising therapeutic option in the future.

A novel pathogenic frameshift variant of CD3E gene in two T-B+ NK+ SCID patients from Turkey.

Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency, which is characterized by the dysfunction and/or absence of T lymphocytes. Early diagnosis of SCID is crucial for overall survival, and if it remains untreated, SCID is often fatal. Next-generation sequencing (NGS) has become a rapid, high-throughput technology, and has already been proven to be beneficial in medical diagnostics. In this study, a targeted NGS panel was developed to identify the genetic variations of SCID by using SmartChip-TE technology, and a novel pathogenic frameshift variant was found in the CD3E gene. Sanger sequencing has confirmed the segregation of the variant among patients. We found a novel deletion in the CD3E gene (NM000733.3:p.L58Hfs*9) in two T-B+ NK+ patients. The variant was not found in the databases of dbSNP, ExAC, and 1000G. One sibling in family I was homozygous and the rest of the family members were heterozygous for this variant. T cell receptor excision circle (TREC) and kappa-deleting recombination excision circle (KREC) analyses were performed for T and B cell maturation. TRECs were not detected in both patients and the KREC copy numbers were similar to the other family members. In addition, heterozygous family members showed decreased TREC levels when compared with the wild-type sibling, indicating that carrying this variant in one allele does not cause immunodeficiency, but does effect T cell proliferation. Here, we report a novel pathogenic frameshift variant in CD3E gene by using targeted NGS panel.