Background and Purpose: It is a matter of research, whether children with immunodeficiencies are able to generate an effective immune response to prevent SARS-CoV-2 reinfection. This study aimed to evaluate and compare the seroconversion rates and changes of lymphocyte subsets during COVID-19 in immunocompetent children and those with secondary immunodeficiencies. Methods: In 55 children — 28 immunocompromised and 27 immunocompetent — hospitalized with confirmed SARS-CoV-2 infection, the level of IgG antibodies against the Spike protein was determined on two to three occasions. In those children from the study group whose immunosuppressive treatment did not alter during the study (n = 13) and in selected children from the control group (n = 11), flow cytometric evaluation of lymphocyte subsets was performed twice — 2 weeks and 3 months post-infection. Results: Seroconversion reached 96.3% in both studied groups; however, the immunocompromised cohort achieved lower titers of detectable anti-S antibodies. There was no correlation between seroconversion or titers of antibodies and the total number of lymphocytes or their subsets. In the immunocompetent cohort, we reported a significant decrease in NK cells during the infection. In this group and the entire study population, a positive correlation was noticed between the CD4 + /CD8 + T cell ratio and the severity of COVID-19 pneumonia. Conclusions: Children with secondary immunodeficiencies seroconvert in equal percentages but with a significantly lower titer of anti-S antibodies compared to their immunocompetent peers. The lower number of NK cells in the immunocompetent cohort may result from their participation in antiviral immunity, whereas reduced CD4 + /CD8 + T cell ratios among immunocompromised children may be a protective factor against a severe COVID-19.

Even after two years of the Coronavirus Disease 2019 (COVID-19) pandemic, despite known risk factors, we are still unable to predict the severity of the infection in specific patients. Due to the contradictory data, the protective role of immunosuppression in preventing the severe course of the infection remains uncertain. Therefore, we want to discuss the influence of several immunosuppressive factors on the COVID-19 pattern in children, based on two case reports regarding 17-year-old boys with other immunosuppressive factors and a completely different course of the disease. The first patient suffered from AIDS, syphilis and primary central nervous system B-cell lymphoma, treated with radiotherapy. He experienced a light path of the infection, presenting only periodically appearing cough with no X-ray inflammatory changes. Nevertheless, due to the risk of severe COVID-19 and transient hypoxia, remdesivir was administered. He remained in a generally good condition and his follow-up did not reveal any noticeable complications. The second patient was characterised by Down syndrome, obesity, polyarteritis nodosa and chronic immunosuppressive therapy. He developed massive pneumonia, required treatment in the intensive care unit with the use of mechanical ventilation, remdesivir and anakinra. Despite the initial improvement of his general condition, including the degree of lung involvement and respiratory function, he developed an intracerebral haemorrhage, leading to brain herniation and ultimately death. In conclusion, HIV infection, oncological and immunosuppressive treatment do not seem to predispose to the severe course of COVID-19, whereas Down syndrome and obesity do.

In the course of atopic dermatitis (AD), the overactivity of the immune system, associated with predominant Th2 lymphocyte responses, is observed, which leads to an increased inflammatory reaction. Cases of a severe course of atopic dermatitis lead to the search for new therapeutic options. The aim of this study was to assess the effects of hyperbaric oxygen therapy (HBOT) treatment for severe cases of AD in children. A total of 15 children with severe AD underwent therapy. The influence of HBOT on the clinical course of AD and immunomodulatory effect of the therapy was analyzed by the SCORAD and objective SCORAD (oSCORAD) scales and by determining the serum concentration of immunological parameters (blood: nTreg lymphocytes, CD4+CD25highCD127-FOXP3+, NKT lymphocytes CD3+, CD16/56+, and serum: total IgE, cytokines IL-4, IL-6, and IL-10, before and after the 30-day treatment cycle). The study showed a significant effect of the therapy on the improvement of the skin condition. In all children, a reduction in the extent and intensity of skin lesions, reduction of redness, swelling, oozing/crusting, scratch marks and skin lichenification after HBOT was observed. Patients also reported a reduction in the intensity of pruritus and an improvement in sleep quality after therapy. In all children, a statistically significant decrease in the serum level of IgE was observed. However, no statistically significant changes in the blood levels of IL-4, IL-6 and IL-10, as well as the percentage of CD4⁺CD25^highCD127⁻FOXP3⁺ Treg and NKT lymphocytes, were found. In conclusion, the use of hyperbaric therapy has a positive impact on treatment results in children with a severe course of atopic dermatitis.

The aim of this retrospective study was the assessment of the prevalence, clinical characteristics, and the comparison of the course of SARS-CoV-2 infection in children with and without immunodeficiency that were admitted to the COVID-19 Subunit of the tertiary referral hospital in Warsaw, Poland. We analysed 313 children hospitalised in the COVID-19 Subunit. The analysis was performed on the total study group and subgroups of children with and without immunodeficiency. In each group, clinical data and laboratory test results were analysed. Of the 68 children with isolated fevers, only seven (11.76%) were diagnosed with COVID-19, whereas among those with the accompanying features of respiratory or gastrointestinal infection, only one (3.23%) and ten (16.95%) patients tested positive, respectively. In both groups, the course of the infection was mainly asymptomatic or mild. The children with immunodeficiencies had lower white blood cell and lymphocyte counts, lower haemoglobin levels, and higher urea levels but did not differ in other biochemical variables. To conclude, the most frequently reported symptoms of COVID-19 indicate that this disease among children is only a small percentage. In both groups, the responses to the infection were comparable in terms of the mild clinical symptoms and the laboratory test results. Therefore, SARS-CoV-2 infection should not alter the chronic treatment of underlying diseases.

Background and PurposeIt is a matter of research, whether children with immunodeficiencies are able to generate an effective immune response to prevent SARS-CoV-2 reinfection. This study aimed to evaluate and compare the seroconversion rates and cellular immunity to COVID-19 in immunocompetent children and those with secondary immunodeficiencies. MethodsIn 55 children — 28 immunocompromised and 27 immunocompetent — hospitalized with confirmed SARS-CoV-2 infection, the level of IgG antibodies against the Spike protein was determined on two to three occasions. In those children from the study group, whose immunosuppressive treatment did not alter during the study (n=13) and in selected children from the control group (n=11), flow-cytometric evaluation of lymphocyte subsets was performed twice — two weeks and three months post-infection. ResultsSeroconversion reached 96.3% in both studied groups, however, the immunocompromised cohort achieved lower titers of detectable anti-S antibodies. There was no correlation between seroconversion or titers of antibodies and the total number of lymphocytes or their subsets. In the immunocompetent cohort, we reported a significant decrease in NK cells during the infection. In this group and the entire study population, a positive correlation was noticed between the CD4+/CD8+ T cell ratio and the severity of COVID-19 pneumonia. ConclusionsChildren with secondary immunodeficiencies seroconvert in equal percentages but with a significantly lower titer of anti-S antibodies compared to their immunocompetent peers. Lower number of NK cells in the immunocompetent cohort may result from their participation in antiviral immunity. Whereas reduced CD4+/CD8+ T cell ratios among immunocompromised children can be a protective factor against a severe COVID-19.