Hot topics in allergen immunotherapy, 2023: Current status and future perspective.

The importance of allergen immunotherapy (AIT) is multifaceted, encompassing both clinical and quality-of-life improvements and cost-effectiveness in the long term. Key mechanisms of allergen tolerance induced by AIT include changes in memory type allergen-specific T- and B-cell responses towards a regulatory phenotype with decreased Type 2 responses, suppression of allergen-specific IgE and increased IgG1 and IgG4, decreased mast cell and eosinophil numbers in allergic tissues and increased activation thresholds. The potential of novel patient enrolment strategies for AIT is taking into account recent advances in biomarkers discoveries, molecular allergy diagnostics and mobile health applications contributing to a personalized approach enhancement that can increase AIT efficacy and compliance. Artificial intelligence can help manage and interpret complex and heterogeneous data, including big data from omics and non-omics research, potentially predict disease subtypes, identify biomarkers and monitor patient responses to AIT. Novel AIT preparations, such as synthetic compounds, innovative carrier systems and adjuvants, are also of great promise. Advances in clinical trial models, including adaptive, complex and hybrid designs as well as real-world evidence, allow more flexibility and cost reduction. The analyses of AIT cost-effectiveness show a clear long-term advantage compared to pharmacotherapy. Important research questions, such as defining clinical endpoints, biomarkers of patient selection and efficacy, mechanisms and the modulation of the placebo effect and alternatives to conventional field trials, including allergen exposure chamber studies are still to be elucidated. This review demonstrates that AIT is still in its growth phase and shows immense development prospects.

Immunosuppressive properties of human PD-1 + , PDL-1 + and CD80 + dendritic cells from lymph nodes aspirates of lung cancer patients.

Dendritic cells (DCs) play a pivotal role in the homeostasis of the immune system. The tumor microenvironment impairs the proper function of DCs. The immunomodulatory properties of DCs in lung cancer are of interest. In the present study, we analysed DCs subsets and immune cells with the expression of immunomodulatory molecules: PD-1 and PD-L1 and co-stimulatory molecule CD80 in metastatic, non-metastatic lymph nodes (LNs) and peripheral blood (PB). LNs aspirates were obtained during the EBUS/TBNA procedure of 29 patients with primary lung cancer. The cells were analyzed by flow cytometry. We reported a higher percentage of DCs in the metastatic than in the non-metastatic LNs and the PB (0.709% vs. 0.166% vs. 0.043%, p < 0.0001). The proportions of PD-1 + , PD-L1 + and CD80 + DCs were higher in the metastatic LNs than in the non-metastatic ones. A higher proportion of regulatory DCs (DCregs) was found in the metastatic ones than in the non-metastatic LNs (22.5% vs. 3.1%, p = 0.0189). We report that DCs cells show increased expression of PD-1, PD-L1 and CD80 molecules that can interact with T lymphocytes. It can be assumed that mature DCs infiltrating metastatic LNs can develop into DCregs, which are involved in the suppression of anti-tumor response.

Secondary immunodeficiencies with predominant antibody deficiency: multidisciplinary perspectives of Polish experts.

At present, secondary immune deficiencies have become a clinical problem, recognized in different specialties. The aim of this paper was to increase awareness and support the need for screening at-risk populations. Secondary immune deficiencies result in variety of conditions, but not all of them require immunoglobulin replacement therapy, as specific antibody response might be preserved. Moreover, the management of secondary immune deficiencies vary between countries and different medical disciplines. This literature review presents the most common causes and clinical presentation of secondary immunodeficiencies with predominant impaired antibody production. We present diagnostic guidelines for patients at-risk, with an emphasis on the role of prophylactic vaccination as a treatment and diagnostic tool. This review considers the specificity and disparities of the Polish healthcare system and ultimately, suggests that management teams should include a clinical immunologist experienced in the treatment of humoral immunodeficiencies.

Angioedema. Interdisciplinary diagnostic and therapeutic recommendations of the Polish Dermatological Society (PTD) and Polish Society of Allergology (PTA).

Angioedema is a non-inflammatory oedema of the subcutaneous tissue and/or mucosal membranes. It most commonly coexists with urticaria wheals and is considered to be a deep form of urticaria. Less commonly, it occurs in isolation and can take two basic forms: acquired angioedema and hereditary angioedema. Currently, there are 4 defined types of acquired angioedema and 7 types of hereditary angioedema. Treatment of angioedema depends on its form and etiological factors. Especially the genetic form, i.e. hereditary angioedema, is a considerable challenge for medical specialists, particularly dermatologists and allergists.

Biological drugs in the treatment of atopic dermatitis - current recommendations of the Polish Dermatological Society, the Polish Society of Allergology, the Polish Pediatric Society and the Polish Society of Family Medicine.

Atopic dermatitis (AD) is secondary to genetic, immunological and microbiological disorders as well as epidermal barrier defects, which are the main targets of therapy. The disease proceeds with periodic exacerbations. Its development and course are influenced by numerous environmental and individual factors. In recent decades, in industrialized countries, there has been a threefold increase in the incidence of AD. There is also an increasing number of cases resistant to topical treatment. Effective treatment of AD should provide control of clinical symptoms, prevent exacerbations and improve the quality of life of patients. The multifactorial etiopathogenesis and various endotypes and phenotypes of AD justify the tendency to optimize and personalize the therapy. Currently, we recommend the use of dupilumab for the treatment of patients from 12 years of age with moderate and severe atopic dermatitis, who do not respond to topical treatment.

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome persisting to adulthood - an example of a diagnostic and therapeutic challenge.

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is the most common cause of periodic fever in childhood. Reports of adult patients are sparse. In adults the clinical picture is more heterogeneous than in children, so PFAPA can be a real diagnostic challenge. Data regarding treatment efficacy and disease outcome are available mainly for children, whereas for adult patients they are limited and conflicting. Our aim is to increase the awareness about PFAPA among clinical practitioners. We present a case of PFAPA beginning in childhood and without resolution of symptoms in maturity. In our case the diagnostic delay was 15 years. We treated the patient with a prophylactic dose of colchicine. Colchicine helped to control flares and significantly improved the patient's quality of life. Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis in adults is a rare disease, but it should be included in the differential diagnosis of fever of unknown origin in adults.

Epidemiology and direct costs of atopic dermatitis in Poland based on the National Health Fund register (2008-2017).

INTRODUCTION: Epidemiological data indicate significant differences in atopic dermatitis (AD) prevalence between countries. AIM: The purpose of this study is to (i) analyse the recorded prevalence of atopic dermatitis (diagnoses of AD reported to the Polish National Health Fund (NHF)) and to (ii) estimate direct costs of medical care for AD incurred by the NHF. MATERIAL AND METHODS: The analysis was based on data reported to the database of the public payer (NHF). The prevalence rates were calculated using the NHF data and population estimates were obtained from the Central Statistical Office of Poland (GUS). RESULTS: In 2017, the annual prevalence rate of AD in the Polish population was 32.5 per 10,000 inhabitants (34.7/10,000 for women and 30.1/10,000 for men). The highest prevalence was observed in the youngest age groups (300/10,000 in children up to 4 years of age and 141/10,000 in 5-9-year-olds). The prevalence rate decreased with age and AD was the least prevalent in patients over 85 years of age (4/10,000). In 2008-2017, NHF expenditure on AD treatment varied between PLN 19.9 million (EUR 5.6 million) in 2008 and PLN 28.4 million (EUR 6.5 million) in 2016. CONCLUSIONS: The prevalence rates of AD in Poland estimated on the basis of NHF data are significantly lower than those reported in previous epidemiological studies conducted in Poland and worldwide. This may indicate that the prevalence of AD in the Polish population is underestimated or that there are no adequate disease control measures in patients with a confirmed diagnosis.

Clinical and economic impact of a one-year treatment with omalizumab in patients with severe allergic asthma within a drug programme in Poland.

BACKGROUND: Allergic asthma is the most prevalent phenotype of severe asthma where treatment with omalizumab (OMB) has been proven to be particularly beneficial. In Poland, OMB therapy is available and reimbursed within a drug programme where strict inclusion and exclusion criteria are defined. The objective of this study was to present a descriptive analysis regarding the trends in outcomes (clinical, quality of life, costs) among a cohort of patients who satisfy inclusion criteria for the initiation of OMB treatment and who successfully responded to OMB according to a set of objective criteria. METHODS: A retrospective analysis of data collected during the 52 weeks of OMB treatment was carried out. The study population was adolescents and adults with severe allergic asthma that was uncontrolled despite a combination of high-dose inhaled corticosteroids (ICS)/long-acting beta-agonists (LABA) and/or other controllers (leukotriene receptor antagonists (LTRA), sustained-release theophylline, and short- or long-acting muscarinic antagonists (SAMA/LAMA), who were the first to finish the one-year treatment. A clinical and cost analysis for patients included in the programme was conducted comparing the one-year pre-treatment period to the one-year treatment period outcomes. RESULTS: Data of 85 patients who completed the first year of therapy were reviewed and analysed. Add-on OMB treatment resulted in a median decrease in exacerbation rate of 66% relative to the baseline and a reduction in oral steroid (OCS) dose by an average of 7.7 mg. At the end of the 52 weeks of therapy the changes in the quality of life questionnaire (AQLQ) and the asthma control questionnaire (ACQ) scores were 1.86 and 1.45 points, respectively. The mean cost of asthma treatment increased by an average of 15,979 EUR per patient per year (baseline period - 802 EUR/patient/year; OMB treatment - 16,781 EUR/patient/year). The cost to avoid one exacerbation was 17721 EUR. CONCLUSION: The clinical outcomes for the observed subset of patients were highly improved. At the same time, costs of the treatment increased, mainly due to the high OMB costs. Other costs associated with a lower number of hospitalizations and ED and office visits and a reduction in OCS dose decreased. These descriptive data can be used for further investigation in defining patients who benefit the most from OMB treatment in clinical practice.

Anaphylaxis in Poland: the epidemiology and direct costs.

INTRODUCTION: Epidemiological data on anaphylaxis have been underestimated both in Poland and worldwide. AIM: To evaluate the prevalence of anaphylaxis in Poland, including a classification by gender, age and residential region. MATERIAL AND METHODS: The data used in the analysis were derived from two sources, the National Health Fund records of healthcare services for 2008-2015 (official statistics) and a questionnaire-based survey conducted in 2015 on a sample of 305 allergists practicing in different regions of Poland. RESULTS: In 2015, 3144 people received treatment for anaphylactic shock (T78.0, T78.2, T80.5, T88.6) with an estimated prevalence rate of anaphylaxis of 8.2 per 100,000 (8.4 for females and 7.9 for males). The highest prevalence rate was found for women aged 50-54 years (14.5 per 100,000). There was a very large difference in the prevalence of anaphylaxis between rural and urban areas (13.1 vs. 0.8 per 100,000). In 2015, the Polish NHF spent PLN 3.5 million (EUR 835,000) on the management of anaphylaxis. Of the allergists surveyed, 73% had been currently managing patients who had experienced anaphylactic shock. The most common causes of anaphylaxis included insect venom (41.4%), food (29.8%) and drugs (17.4%). CONCLUSIONS: A central anaphylaxis registry should be established in Poland. This is the only approach that would allow collecting a wide range of reliable information on the cases, management and consequences of anaphylaxis. Ongoing management of patients who have experienced anaphylactic shock should be improved.

[Autoimmune connective tissue diseases and vaccination]. / Autoimmunizacyjne ukladowe choroby tkanki lacznej a szczepienia ochronne.

The idea that infectious agents can induce autoimmune diseases in genetically susceptible subjects has been a matter of discussion for years. Moreover, increased incidence of autoimmune diseases and introduction of prophylactic vaccinations from early childhood suggest that these two trends are linked. In the medical literature and even non-professional media, case reports or events temporally related to vaccination are reported. It raises the issue of vaccination safety. In everyday practice medical professionals, physicians, rheumatologists and other specialists will be asked their opinion of vaccination safety. The decision should be made according to evidence-based medicine and the current state of knowledge. The purpose of this paper is to discuss a potential mechanism which links infections, vaccinations and autoimmunity. We present an overview of published case reports, especially of systemic connective tissue diseases temporally related to vaccination and results from case-nested studies. As yet, no conclusive evidence supports a causal relationship between vaccination and autoimmune diseases. It has to be determined whether the performed studies are sufficiently sensitive to detect the link. The debate is ongoing, and new data may be required to explain the pathogenesis of autoimmunity. We would like to underscore the need for prophylactic vaccination in patients with autoimmune rheumatic diseases and to break down the myth that the vaccines are contraindicated in this target group.

[The costs of asthma in Poland in 2012]. / Koszty astmy w Polsce w 2012 roku.

UNLABELLED: The costs incurred for treatment of patients with asthma are an important part of health care in the budget of each country. The aim of the study was to evaluate the direct and indirect costs of asthma in Poland. The study was based on questionnaires completed by professionals--allergists and pneumonologists of 13 centers in which is conducted the diagnosis and treatment of asthma. MATERIALS AND METHODS: The costs of asthma were determined from the payer perspective (NHF) and from the perspective of social security (ZUS). The study evaluated the direct costs of one patient with asthma in 2012, and indirect costs, as measured by human capital or friction costs. The study involved 128 people, including 84 women and 44 men, mean age 51.04+/11.41 years. RESULTS: Among the most frequent concomitant diseases: allergic rhinitis (93.75%), gastro-oesophageal reflux (38.54%), urticaria (16.67%), atopic dermatitis (21.88%) were present. The average monthly cost of drugs in 2012 amounted to PLN 251.32 (61.29 EURO, 2012 EURO 1 year=4.1 PLN), including patient,s copayment amounted to PLN 65.48 (EUR 15.97). The study showed that the direct cost per patient was 3240,88 PLN (790,46 EURO,). The Indirect cost, calculated using the human capital was for an average PLN 17,579.18 (4287.6 EURO) per patient, and using the method of friction costs was PLN 5974.06 (EUR 1,457.2). CONCLUSIONS: Estimating the cost of the disease often depends on the adopted method of analysis, but in the study group, a significant advantage of the indirect costs of the disease was observed. The effectiveness of the treatment of asthma in Poland should also be aimed at reducing the indirect costs of illness.

Epidemiology of asthma in Poland in urban and rural areas, based on provided health care services.

INTRODUCTION: Asthma is a serious health and social problem, also in Poland. The epidemiological data indicate that the problem of asthma concerns approximately 4 million people in Poland, whereas almost approximately 70% of them have no diagnosis and are not aware of their illness, and on the other hand in 39% of persons who declared the diagnosis of asthma in a survey the diagnosis was negatively verified (overdiagnosis of asthma). So far, no detailed comparative studies for asthma incidence rate in urban and rural areas were conducted in Poland. The aim of the study was to analyze patients with asthma in Poland in the years 2008-2012, with regard to province and type of commune (rural/urban). MATERIAL AND METHODS: The study used data from National Health Fund (NFZ) - reported by health care providers regarding the patients diagnosed with asthma. Using structured query language (SQL) a set of patients was selected and created, for whom at the same time ICD-10 code: J45.X-bronchial asthma was reported. In order to estimate the number of patients with asthma we used the PESEL social security number as a unique identifier of the patient. Code of the patient's commune of residence in conjunction with the Central Statistical Office data formed the basis for the division of municipalities into urban and rural areas. The analysis of asthma incidence trends in Poland was performed on the basis of health services provided to patients. The analysis was performed by using the Statistica 10 software using a negative binomial regression model. RESULTS: In 2009 a significant increase in the number of patients with asthma was observed compared with the previous year, whereas after 2009 the number of patients diagnosed with asthma remained relatively constant. A significant increase of predominance of women among asthma patients in recent years can be noticed: from 107% in 2008 to almost 115% in 2012 (F:M ratio). Regardless of the analyzed year and the diagnosis the incidence rate remained constant: approximately 55-57% for urban areas and about 43-45% in rural areas. CONCLUSIONS: The average prevalence rate for rural areas is significantly lower than for urban areas. The use of adjusted incidence rate leads to the conclusion that the number of sufferers in urban areas is higher (about 10%) of the number of sufferers in the rural areas. The results of the analysis are consistent with information from previous studies in Poland and in the world.

[The Polish Task Force position statement on safety of biologic treatment with monoclonal antibodies and soluble receptors]. / Stanowisko Polskiej Grupy Ekspertów dotyczace bezpieczenstwa leczenia przeciwcialami monoklonalnymi i bialkami fuzyjnymi.

UNLABELLED: The introduction of biologic therapies for treatment in many fields of medicine such as rheumatology oncology, dermatology, hematology and allergology, became one of the most important achievements of the modem medicine. The first biological therapeutics have already reached patent expiration date and corresponding biosimilars were approved by EMA (European Medicine Agency) and FDA (Food and Drug Administration). Many more biosimilar products are currently under review for marketing authorization around the world. The approval of products similar, but not identical to already known innovative biologics, due to complexity of structure and manufacturing technology, stirs a lot of discussions regarding safety concerns related to differences in posttranslational processing and in immunogenicity between reference and biosimilar products, and relevance of these differences to the clinical practice. Critical issues involve extrapolation to different clinical indication, automatic substitution and switching. Despite EMA recommendation and advocacy for biosimilars, it is beyond this regulatory authority to establish definitive regulation for each EU member, which it is expected to be country related. The aim of the study was an attempt to define the stance regarding particular aspects of biological treatment conducted in Poland is undertaken. METHODS: The Task Force of 13 experts involved in various aspects of biologic therapies in Poland was established. A modified Delphi voting was performed to achieve consensus regarding the most important aspects of biologic treatment in Poland, with particular concern of biosimilars. RESULTS: Ten final statements were discussed and voted upon. The statements cover general aspects of biosimilars including expected cost-benefit ratios, extrapolation of clinical indications, interchange switching, patient information and requirement of patient consent. The state of post marketing pharmacovigilance of biologics (innovative ones as well as biosimilars) was also discussed. CONCLUSIONS: The Task Force agreed that introduction of biosimilars is an important achievement in the biological therapies, with potential for reduction of treatment cost and increased treatment availability. Experts also agree that the safety of biological treatment should be monitored more carefully in Poland. Other discussed issues sparked more questions. There is no consensus among experts as to the automatic interchangeability of biosimilar and their innovative biopharmaceuticals. However, the switching might be acceptable in clinical practice on the case by case basis. There is an unmet need in Poland to create registry collecting data sufficient for assessment of safety and efficacy of both biosimilars and reference products in accordance with the experience and principles introduced in the European countries.

[Influence of inhaler and fine particle on efficacy of inhalation therapy in COPD]. / Wplyw doboru inhalatora i czastki na skutecznosc terapii wziewnej w POChP.

Orally inhaled products delivered via inhalation exert their effect directly to the target organ. This allows to administer a very low dose of a drug compared with an oral route with similar clinical effect and significantly reduced toxicity. However inhalation therapy is also limited by several factors. Delivery of the desired dose of the drug to the airways depends on a type of the inhaler - pressurised metered-dose inhaler (pMDI) or dry powder inhaler (DPI), inhaler characteristics (low or high internal resistance, diameter of particles and distribution of the generated aerosol fine particles), thermal conditions of air, and ability of patient to generate sufficient inspiratory flow (for DPI) or to coordinate actuation with inhalation (for pMDI). Unlike pMDIs, DPIs are breath- -actuated, hence avoiding the need for the patient to coordinate actuation with inspiration. Furthermore, DPIs are propellant-free and do not produce the cold sensation on inhalation. Currently available DPIs vary widely in design, operating characteristics and performance. And poor inhalation technique may compromise treatment efficacy. Hence, there is a clear need for a careful selection of DPIs for different patient groups, including children, elderly patients and those with severe airway obstruction.

Case report: VEXAS as an example of autoinflammatory syndrome in pulmonology clinical practice.

Lung involvement is not widely recognized as a complication of auto-inflammatory diseases. We present a broad approach to diagnose a severe form of autoinflammatory syndrome in an adult male patient. A 63-year-old Caucasian male presented with recurrent episodes of high fever, interstitial lung infiltration, and pleural effusion. Laboratory tests performed during the flares revealed lymphopenia and increased levels of C-reactive protein and ferritin. Broad diagnostic research on infections, connective tissue diseases, and malignancies yielded negative results. The patient's symptoms promptly resolved upon the administration of glucocorticoids; however, they reappeared when the prednisone dose was reduced. All attempts to administer immunomodulatory and immunosuppressive medications were ineffective. During follow-up, autoinflammatory syndrome was suspected; however, no pathological variants of monogenic autoinflammatory diseases were identified by genome-exome sequencing. The patient did not respond to interleukin 1 blockade with anakinra. He died due to multi-organ failure, and his condition remained unresolved until the first reported description of vacuole, E1 enzyme, X-linked, autoinflammatory, and somatic syndrome (VEXAS). We describe the diagnostic traps and reasoning process involved in establishing that the patient's symptoms were autoinflammatory in nature based on clinical symptoms, in addition to the proof of concept gained from genetic reevaluation and identification of pathogenic variants in the UBA1 gene. The aim of this review is to increase the awareness of VEXAS among pulmonologists. Genetic screening for UBA1 should be considered in patients with recurrent pneumonitis of unknown origin with elevated inflammatory markers and signs of cytopenia, especially if they require chronic steroids to control the disease. Respiratory manifestations are part of VEXAS; these may be dominant in the course of the disease and severe at presentation.

Quality of Life in Follow-Up up to 9 Months after COVID-19 Hospitalization among the Polish Population-A Prospective Single Center Study.

The consequences of COVID-19 constitute a significant burden to healthcare systems worldwide. Conducting an HRQoL assessment is an important aspect of the evaluation of the impact of the disease. The aim of this study was to investigate the prevalence of persistent symptoms and their impact on HRQoL and health status in COVID-19 convalescents. The study group consists of 46 patients who required hospitalization due to respiratory failure and who were subsequently evaluated 3 and 9 months after hospital discharge. At the follow-up visits, the patients were asked to assess their HRQoL using the EQ-5D-5L questionnaire. The results of chest CT, 6MWT, as well as the severity of the course of COVID-19 were also considered in the analysis. The obtained results have identified fatigue as the most common persistent symptom. The majority of the convalescents reported an impairment of HRQoL in at least one domain (80% and 82% after 3 and 9 months, respectively), of which the most common was that of pain/discomfort. The presence of ongoing symptoms may affect HRQoL in particular domains. The 6MWT outcome correlates with HRQoL 3 months after hospital discharge. Therefore, it may be useful in identifying patients with reduced HRQoL, allowing early interventions aimed at its improvement.

Pulmonary Function, Computed Tomography Lung Abnormalities, and Small Airway Disease after COVID-19: 3-, 6-, and 9-Month Follow-Up.

Background/Objectives: Coronavirus disease 2019 (COVID-19) course may differ among individuals-in particular, those with comorbidities may have severe pneumonia, requiring oxygen supplementation or mechanical ventilation. Post-COVID-19 long-term structural changes in imaging studies can contribute to persistent respiratory disturbance. This study aimed to investigate COVID-19 sequels affecting the possibility of persistent structural lung tissue abnormalities and their influence on the respiratory function of peripheral airways and gas transfer. Methods: Patients were divided into two groups according to severity grades described by the World Health Organization. Among the 176 hospitalized patients were 154 patients with mask oxygen supplementation and 22 patients with high-flow nasal cannula (HFNC) or mechanical ventilation. All tests were performed at 3, 6, and 9 months post-hospitalization. Results: Patients in the severe/critical group had lower lung volumes in FVC, FVC%, FEV1, FEV1%, LC, TLC%, and DLCO% at three months post-hospitalization. At 6 and 9 months, neither group had significant FVC and FEV1 value improvements. The MEF 25-75 values were not significantly higher in the mild/moderate group than in the severe/critical group at three months. There were weak significant correlations between FVC and FEV1, MEF50, MEF 75, plethysmography TLC, disturbances in DLCO, and total CT abnormalities in the severe/critical group at three months. In a mild/moderate group, there was a significant negative correlation between the spirometry, plethysmography parameters, and CT lesions in all periods. Conclusions: Persistent respiratory symptoms post-COVID-19 can result from fibrotic lung parenchyma and post-infectious stenotic small airway changes not visible in CT, probably due to persistent inflammation.

Increased Access to Immunoglobulin Replacement Therapy for Patients with Primary Immunodeficiency in Poland Based on Clinical Usage Data of Immunoglobulin G over a 5-Year Period.

Owing to the rising popularity and demand for immunoglobulins (IgG), obtaining supplies and rationalizing IgG use have become challenging. Herein, IgG consumption in Poland was analyzed through total IgG use and number of patients reported to the National Health Fund between 1 January 2016 and 31 December 2020. Total IgG used within 5 years increased by 27.48%, IgG use/1000 inhabitants/year was 23.13 g (2016) and 29.61 g (2020). In 2020, 35.5 % of IgG used was for neurological conditions, 25% for primary immunodeficiencies (PID), and 39.3% for all other indications. Within 5 years, 1,121,168.75 g IgG was used in PID; the use increased by 72%, from 783 in 2016 to 1153 patients in 2020. The proportion of patients who received subcutaneous immunoglobulin (SCIG) replacement therapy (IgRT) increased to 78% (2020). Within 5 years, 1,783,534.81 g IgG was used in neurological drug programs (+42.44%) and 2,327,513.88 g (+1.25%) outside neurological indications and outside PID. The annual IgG amount decreased in adult anesthesiology and intensive care (-46%), internal medicine (-55%), pneumonology (-50%), pediatric clinical immunology (-50%), and gynecology and obstetrics (-48%) and increased in dermatology (+178%), rheumatology (+103%), and clinical transplantation (+82%). IgG use significantly increased in Poland, mostly owing to PID. Subcutaneous IgG administration is currently the most common mode of IgRT in PID patients. An increase in SCIG administration may be expected for other indications. Implementing evidence-based clinical guidelines is key to prioritizing and rationalizing IgG use for immunomodulatory indications and secondary immune deficiencies.

Analysis of Leukocyte Subpopulations by Flow Cytometry during Hospitalization Depending on the Severity of COVID-19 Course.

The mechanisms underlying the immune response to coronavirus disease 2019 (COVID-19) and the recovery process have not been fully elucidated. The aim of the study was to analyze leukocyte subpopulations in patients at significant time points (at diagnosis, and 3 and 6 months after infection) selected according to the analysis of changes in the lungs by the CT classification system, considering the severity of the disease. The study groups consisted of severe and non-severe COVID-19 patients. There was a significant decrease in CD8+ T cells, NK and eosinophils, with an increasing percentage of neutrophils during hospitalization. We noticed lower levels of CD4 and CD8 T lymphocytes, eosinophils, basophils, and CD16+ monocytes and elevated neutrophil levels in severe patients relative to non-severe patients. Three months after infection, we observed higher levels of basophils, and after 6 months, higher CD4/CD8 ratios and T cell levels in the severe compared to non-severe group. Non-severe patients showed significant changes in the leukocyte populations studied at time of hospitalization and both within 3 months and 6 months of onset. The CT CSS classification with parameters of the flow cytometry method used for COVID-19 patients determined changes that proved useful in the initial evaluation of patients.