Circulating NK and NKT cells in the diagnosis and treatment of immunological causes of female infertility - retrospective data analysis from the tertiary clinical center.

Immune dysregulation can cause embryo implantation failure, possibly due to mechanisms of innate non-adaptive immunity, including natural killer (NK) and natural killer T (NKT) cells. Retrospective analysis of relative counts and functional properties of NK and NKT peripheral blood cells in women with cellular immunopathology before and after immunomodulatory treatment was realized to evaluate these values in a proportion of clinical post-treatment pregnancies. For retrospective analysis, data were collected from 184 infertile women treated for abnormal functional properties and/or numbers of NK and NKT cells after stimulation with sperm and trophoblast antigens. Flow cytometric analyses of peripheral blood both before and during/after immunomodulatory treatment were performed to determine whether clinical pregnancy was achieved. Of 184 cases, immunomodulatory treatment contributed to clinical pregnancy in 109 women (59 %), all but 25 of whom required assisted reproduction techniques to become pregnant. Clinical pregnancy was associated with significantly lower numbers of circulating NK cells (p = 0.03) and significantly less activation of NK cells by trophoblasts (p < 0.001). Increased numbers of peripheral blood NK cells and their pathological activation by trophoblast antigens are immunological factors of infertility in women. However, when appropriately chosen, immunomodulatory treatment can make clinical pregnancy more likely.

COVID-19-free workplace: Measuring the level of antibodies against coronavirus as a basis for testing strategy in companies.

The Czech Republic is one of the countries most affected by the coronavirus pandemic - approximately 16% of the population had a positive PCR test, 2-3 times more people underwent infection without undergoing this examination. It is particularly useful for employers to know how many employees have already contracted the infection and for how many people are still at risk of the coronavirus infection. For this purpose, it is appropriate to examine IgG antibodies. However, the testing strategy is different at present - antigen testing is mandatory to look for infectious individuals, regardless of human immunity. The aim of the pilot study was to determine the number of immune individuals after infection at three clinics of GENNET s.r.o. At the same time, unvaccinated individuals who had not had COVID-19 or had undergone it more than three months ago were tested with antigen tests. The cohort included 297 subjects, of whom 182 were not vaccinated (61.3 %) and 115 subjects (38.7 %) were after the vaccination. Of the unvaccinated, 71 people had in the past a positive PCR test (39 %), another 18 people had positive IgG antibodies without infection (9.9 %) and 38 people (20.9 %) had negative IgG antibodies. So far, 55 persons (30.2 %) have not been examined. If we add people vaccinated and people with antibodies, then 74.3 % of employees of the GENNET Archa clinic, 68 % of employees from the GENNET Kostelní clinic and 58.1 % from the GENNET Liberec clinic were immune to infection. 153 individuals on average (60 of whom had antibodies) were tested for the antigen test in four rounds. The infection was detected in two people. Both belonged to the group without tested antibodies. No person with antibodies was tested positive for antigen. People who have antibodies after vaccination or infection are substantially less prone to infection and have a low risk of continuing to spread the virus. By examining antibodies, employers will gain a better overview of the situation in the workplace. Based on our study, we recommend including antibody testing into antiepidemic measures and limit antigen testing to seronegative individuals.

Current possibilities of diagnostics and treatment of immunological causes of female infertility.

The immune system plays an important role in many processes of human reproduction. During pregnancy, mother's body has to accept the semialogenic fetus, therefore the role of immune processes has a high importance. Tolerance of the fetus by the mother's immune system is ensured by a complex of immune mechanisms, the knowledge of which brings us to the new insights into human reproduction processes and in seeking of new ways to modulate immunity in repeated embryo implantation failures, miscarriages, premature births, preeclampsia, and other fertility disorders and pregnancy complications. The review article is a summary of current possibilities of immunological laboratory diagnostics in reproductive immunology, presents indications for these tests and their interpretation, and mentions possible methods of therapeutic immune intervention.

Anti-SARS-CoV-2 antibody testing in IBD healthcare professionals: are we currently able to provide COVID-free IBD clinics?

Coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has spread worldwide triggering a pandemic during the year 2020. The proportion of persons infected with SARS-CoV-2 whose infection remained subclinical is not known. However, such information is important to determine whether the control measures currently employed are sufficient to halt the spread of the virus. Current study has examined the seroprevalence of anti-SARS-CoV-2 antibodies in a population of 92 healthcare professionals working with patients with inflammatory bowel disease (IBD). The enzyme-linked immunosorbent assay (ELISA) test system for SARS-CoV-2 IgG from EUROIMMUN Medizinische Labordiagnostika AG (Germany) was used. Very low herd antibody-mediated immunity was proven, less than 2%, although we have been faced with the COVID-19 pandemic for several months. Anti-SARS-CoV-2 IgG antibody testing is currently unable to provide sufficient information about our anti-infectious immunity.

Testing for COVID-19: a few points to remember.

Diagnostic approaches to COVID-19 include clinical history, PCR tests for the presence of SARS-CoV-2 virus and detection of antibodies. By combining these three approaches, the seroprevalence of anti-SARS-CoV-2 antibodies can be examined in healthcare teams. The aim of the study was to examine the seroprevalence of anti-SARS-CoV-2 antibodies in a population of healthcare professionals 6 - 8 weeks after the first COVID-19 case was detected in the Czech Republic. A total of 269 subjects were enrolled in the study (187 women, 82 men) with a median age of 45.9 years (21 - 71 years). We used a questionnaire to ascertain travel history and clinical signs of any respiratory tract infection. Blood samples were collected, and IgG levels were analysed in all samples. The level of IgA antibodies was analysed in those positive for IgG. PCR testing was performed in cases testing positive for presence of antibodies. The enzyme-linked immunosorbent assay (ELISA) test system for SARS-CoV-2 from Euroimmun (Germany) was used to analyse immunoglobulin levels. 17 % of the tested cohort reported symptoms compatible with COVID-19 and 35.8 % reported history of international travel. There were 5 subjects positive IgG cases (of 269; 1.85 %), and one IgA positive and IgG borderline positive subject (0.37 %). There was only one PCR positive subject. Anti SARS-CoV-2 antibodies were thus detected in 2.22% of participating health professionals. This article shows the pitfalls of the testing methods and highlights the necessity of using a correct testing algorithm, considering the character of the tested population and the expected low prevalence.