Immunological Evaluation Research Articles

Polysaccharide, Conjugate, and mRNA-based Vaccines are Immunogenic in Patients with Netherton Syndrome

BackgroundNetherton syndrome (NS) is a rare, severe genetic skin disorder, currently classified as an inborn error of immunity (IEI) due to previously reported immune dysregulation. We recently reported the results of an immunological evaluation showing no evidence for a relevant B- and/or T-cell mediated immunodeficiency, but immune responses after vaccination were not evaluated in that study. Therefore, we evaluated immune responses to three vaccine platforms in adult NS patients to further investigate the presence of a clinically relevant B- and/or T-cell immunodeficiency.MethodsVaccination responses in eight adult NS patients were assessed in a cross-sectional study performed between January and August 2022. Clinical patient data were retrospectively retrieved from electronic patient files. Immune responses to a polysaccharide Streptococcus pneumoniae vaccine (PPV23) and conjugate Haemophilus influenzae type b vaccine (ActHiB) were measured. SARS-CoV-2-specific (functional) antibody and T-cell responses following booster vaccination with an mRNA-based COVID-19 vaccine were compared to controls.ResultsNone of the included patients suffered from recurrent and/or severe infections that could be attributed to a B- and/or T-cell immunodeficiency. ActHiB induced immune responses were normal in 7/7 NS patients. PPV23 induced responses were absent in 1/7, diminished in 2/7, and normal in 4/7 patients. Levels of SARS-CoV-2-specific binding and neutralizing antibodies after mRNA-based COVID-19 booster vaccination in NS patients were comparable to controls. SARS-CoV-2-specific CD4 + T-cell responses were detectable in all NS patients. In contrast, SARS-CoV-2-specific CD8 + T-cell responses were detectable in only 2/6 NS patients. T-cell responses to a positive control antigen pool were comparable to controls.ConclusionsVaccine-induced immune responses were detectable after polysaccharide, conjugate and mRNA-based vaccination in our cohort of NS patients. A spectrum of responsiveness to vaccine challenges was found, with the ranges of vaccine responses overlapping those demonstrated in healthy control populations.

Long-term immunological changes after corrective cardiacsurgery.

Infants with congenital heart disease (CHD) often undergo thymectomy during corrective cardiac surgery (CCS). The long-term immunological effects remain controversial, with concerns regarding increased susceptibility to infections, allergies, autoimmunity due to compromised immune tolerance mechanisms. This study aims to elucidate the long-term immunological effects of early thymectomy. We enrolled 22 patients who underwent thymectomy in infancy and were followed up in the Pediatric Allergy and Immunology Clinic at Marmara University. We performed demographic characteristics and detailed immunological evaluation, including immunoglobulins, vaccine responses, lymphocyte subset analyses, upregulation, proliferation of T cells and T-cell receptor excision circles (TRECs). Sixteen patients had a history of infection, including six serious infections, all in the first year. Lymphopenia was observed in 27% of patients, with a significant decrease in naive CD4+ and recent thymic emigrant T cells counts and an increase in the proportion of memory T-cells, indicating premature immune senescence. Low levels of IgG, IgA and IgM were found in 36%, 40% and 22% of patients respectively. Vaccine responses were positive in 90% of patients. TREC levels were low in all 10 patients analysed. Seven of nine patients had normal proliferation. Twenty-two percent of patients had allergic disease, and autoimmunity was not observed. Early thymectomy leads to permanent immunological changes that are indicative of early immunosenescence. It is recommended to preserve thymic tissue during surgery and requires long-term follow-up in terms of findings such as allergy and autoimmunity as well as infections due to impaired immune tolerance mechanisms.

Integration of bioinformatics and cellular experiments unveils the role of SYT12 in gastric cancer

ObjectiveThis study employs integrated bioinformatics analysis and in vitro cellular experiments to elucidate the role of Synaptotagmin-12 (SYT12) in the progression of gastric cancer.MethodsWe utilized databases and platforms such as Xiantao Academic Tools, UALCAN, Kaplan-Meier plotter analysis, and The Cancer Genome Atlas (TCGA) to extract datasets on SYT12 in gastric cancer. We analyzed the relationship between SYT12 expression and the clinicopathological features, prognosis, diagnosis, and immune infiltration of stomach adenocarcinoma (STAD) patients. Verification was conducted using samples from 31 gastric cancer patients. Additionally, in vitro cellular experiments were performed to determine the role and potential mechanisms of SYT12 in the malignant behavior of gastric cancer cells.ResultsComprehensive bioinformatics analysis indicated that SYT12 is highly expressed in most cancers and is associated with promoter DeoxyriboNucleic Acid (DNA) methylation levels. SYT12 expression correlated with clinicopathological features, immune cell infiltration, immune checkpoint gene expression, and poor prognosis in STAD patients. In vitro experiments suggest that SYT12 may promote the proliferation and migration of gastric cancer cells by inducing epithelial-mesenchymal transition (EMT).ConclusionsThis study highlights the significant role of SYT12 in gastric cancer, suggesting its potential as a new target for early diagnosis, treatment, immunological, and prognostic evaluation in gastric cancer, offering new insights for precision medicine in this disease.

Dissecting Secondary Immunodeficiency: Identification of Primary Immunodeficiency within B-Cell Lymphoproliferative Disorders

Distinguishing between primary (PID) and secondary (SID) immunodeficiencies, particularly in relation to hematological B-cell lymphoproliferative disorders (B-CLPD), poses a major clinical challenge. We aimed to analyze and define the clinical and laboratory variables in SID patients associated with B-CLPD, identifying overlaps with late-onset PIDs, which could potentially improve diagnostic precision and prognostic assessment. We studied 37 clinical/laboratory variables in 151 SID patients with B-CLPD. Patients were classified as “Suspected PID Group” when having recurrent-severe infections prior to the B-CLPD and/or hypogammaglobulinemia according to key ESID criteria for PID. Bivariate association analyses showed significant statistical differences between “Suspected PID”- and “SID”-groups in 10 out of 37 variables analyzed, with “Suspected PID” showing higher frequencies of childhood recurrent-severe infections, family history of B-CLPD, significantly lower serum Free Light Chain (sFLC), immunoglobulin concentrations, lower total leukocyte, and switch-memory B-cell counts at baseline. Rpart machine learning algorithm was performed to potentially create a model to differentiate both groups. The model developed a decision tree with two major variables in order of relevance: sum κ + λ and history of severe-recurrent infections in childhood, with high sensitivity 89.5%, specificity 100%, and accuracy 91.8% for PID prediction. Identifying significant clinical and immunological variables can aid in the difficult task of recognizing late-onset PIDs among SID patients, emphasizing the value of a comprehensive immunological evaluation. The differences between “Suspected PID” and SID groups, highlight the need of early, tailored diagnostic and treatment strategies for personalized patient management and follow up.

Inborn Errors of Immunity in Pediatric Intensive Care: Prevalence, Characteristics, and Prognosis.

Inborn errors of immunity (IEI) are a heterogeneous group of genetic diseases characterized by impaired immune system function. This prospective study aimed to determine the frequency, characteristics, and clinical course of IEI patients admitted to the pediatric intensive care unit (PICU) and identify mortality-related factors. Using a comprehensive immunological evaluation protocol, we screened 753 PICU admissions for potential IEIs during three years. Patients with pre-existing IEI diagnoses, chronic diseases, ongoing chronic medication regimens, other known comorbidities, trauma cases, post-surgical cases, and poisonings were excluded. Thirty-three patients were newly diagnosed with IEIs during or as a result of their PICU stay, representing an incidence of 4.39%. The most common disorders were immunodeficiencies with immune dysregulation (48.5%), followed by combined immunodeficiencies (24.2%). Severe viral infections (61%) and life-threatening infections (51.7%) were the most frequent warning signs. Only 31% of patients exhibited at least two Jeffrey Modell Foundation warning signs. The mortality rate was 58%, highlighting the need for early diagnosis and treatment. Newborn screening and family segregation studies are crucial to improving outcomes for IEI patients in intensive care settings.

The Power of Reagent Titration in Flow Cytometry.

Flow cytometry facilitates the detection of multiple cell parameters simultaneously with a high level of resolution and throughput, enabling in-depth immunological evaluations. High data resolution in flow cytometry depends on multiple factors, including the concentration of reagents used in the staining protocol, and reagent validation and titration should be the first step in any assay optimization. Titration is the process of finding the concentration of the reagent that best resolves a positive signal from the background, with the saturation of all binding sites, and minimal antibody excess. The titration process involves the evaluation of serial reagent dilutions in cells expressing the antigen target for the tested antibody. The concentration of antibody that provides the highest signal to noise ratio is calculated by plotting the percentage of positive cells and the intensity of the fluorescence of the stained cells with respect to the negative events, in a concentration-response curve. The determination of the optimal antibody concentration is necessary to ensure reliable and reproducible results and is required for each sample type, reagent clone and lot, as well as the methods used for cell collection, staining, and storage conditions. If the antibody dilution is too low, the signal will be too weak to be accurately determined, leading to suboptimal data resolution, high variability across measurements, and the underestimation of the frequency of cells expressing a specific marker. The use of excess antibodies could lead to non-specific binding, reagent misuse, and detector overloading with the signal off scale and higher spillover spreading. In this publication, we summarized the titration fundamentals and best practices, and evaluated the impact of using a different instrument, sample, staining, acquisition, and analysis conditions in the selection of the optimal titer and population resolution.

A Rare Case of TP63-Associated Lymphopenia Revealed by Newborn Screening Using TREC

The expanded newborn screening (NBS) program in the Russian Federation was initiated in 2023, among which severe combined immunodeficiency (SCID) is screened using TREC/KREC assays. Here, we report a rare case of a TP63-associated disease identified through this NBS program. Dried blood spots from newborns were initially screened for TREC/KREC levels, and those with values below the cut-off underwent confirmatory testing and further genetic analysis, including whole-exome sequencing (WES). A male newborn was identified with significantly reduced TREC values, indicative of T cell lymphopenia. Genetic analysis revealed a heterozygous NM_003722.5:c.1027C>T variant in TP63, leading to the p.(Arg343Trp) substitution within the DNA binding domain. This mutation has been previously associated with Ectrodactyly–Ectodermal Dysplasia–Cleft lip/palate syndrome (EEC) syndrome and shown to reduce the transactivation activity of TP63 in a dominant-negative manner. This case represents one of the few instances of immune system involvement in a patient with a TP63 mutation, highlighting the need for further investigation into the immunological aspects of TP63-associated disorders. Our findings suggest that comprehensive immunological evaluation should be considered for patients with TP63 mutations to better understand and manage potential immune dysfunctions.

Investigating Concomitant RAG-2 and LRBA Mutations in SCID and Autoimmunity.

Inborn errors of immunity (IEI) are a large heterogenous group of diseases characterized by immunodeficiency, immune dysregulation, allergy, auto-inflammation and predisposition for malignancies. Most are inherited in an autosomal recessive trait. We studied a patient with severe combined immunodeficiency (SCID) and immune dysregulation who harbored two distinct bi-allelic IEI-associated genetic mutations. Clinical, immunological and genetic data were collected. Genetic investigation included whole exome sequencing on DNA extracted from skin fibroblasts. Family segregation was performed by Sanger sequencing. Immunological evaluation included absolute and functional evaluation of lymphocytes and chimerism analysis post hematopoietic stem cell transplantation (HSCT). Treg subsets, LRBA and CTLA4 expression levels were measured by flow-cytometric analysis. A nineteen-year-old female patient from a consanguine background underwent unconditioned matched sibling related HSCT during infancy due to clinical presentation of SCID with an Omenn phenotype. At that time her underlying genetic defect was not defined. Years after HSCT, severe auto-immune phenomena were noted, including a systemic lupus erythematosus-like syndrome and ophthalmic manifestations. Genetic evaluation revealed bi-allelic homozygous mutations in RAG-2 (c.685C>T, p.Arg229Trp) and a previously undescribed mutation in LRBA (c.3325G>T, p.Asp1109Tyr). LRBA and CTLA4 expression levels were normal, suggesting that the LRBA variant identified in these kindred is unlikely to be pathogenic. Multiple genetic defects causing complex IEIs may be identified in the same individual in highly consanguineous populations. Functional immunological testing is essential for evaluation of novel genetic variants.

Transplantation Genetics: The Importance of non-HLA Antibodies, Genetic Insights and Future Perspectives

Solid organ transplantation is an effective and life-saving treatment method for patients with end-stage organ failure. Immunological evaluation is of great importance in the achievement of transplantation, and the determination of HLA incompatibility forms the basis of immunological transplantation success. The presence of donor HLA-related antibodies is known to be asssociated with graft loss and decreased survival rates. However, recent studies have shown clinical and experimental findings related to the important role of non-HLA antibodies in the antibody-mediated rejection and chronic rejection process. The mechanisms triggering auto-antibody production in organ transplantation are an important area of research. These mechanisms stimulate auto-antibody production in the patient causing the expression of organ-origin autoantigens such as ischaemia-reperfusion damage, surgical trauma, alloimmune responses, soluble antigens, extracellular vesicles and apoptotic bodies. In patients with a risk of non-HLA antibody-mediated rejection, there is an urgent need to determine the recipient immunological phenotypes, both for the development of targetted treatments and to increase both graft and patient survival. The aim of this review was to evaluate non-HLA antibody types and their effects on transplantation.

The lung in inborn errors of immunity.

The lungs are integral to immune defense, and inborn errors of immunity (IEI) often manifest as lung disease. Lung complications of IEI can involve the airways, alveolar spaces, interstitium, vasculature, and pleura. Accurate identification of these lung disease patterns requires a thorough clinical history, physical examination, and high-resolution computed tomography (HRCT), as lung imaging patterns guide further respiratory and immunological evaluations. Respiratory assessment may also include pulmonary function tests, bronchoscopy with bronchoalveolar lavage, and, in some cases, lung biopsy. Additionally, molecular diagnosis of underlying immune defects, typically through comprehensive clinical phenotyping, functional immune studies, and genetic testing, is crucial for informing patient management and guiding targeted therapies. Importantly, given the complexity of IEI, a multidisciplinary approach is necessary. Furthermore, ongoing research is required to refine therapies and improve outcomes for lung complications.

Systematic Evaluation of Regiochemistry and Lipidation of Aryl Trehalose Mincle Agonists.

The Macrophage-Inducible C-type Lectin receptor (Mincle) plays a critical role in innate immune recognition and pathology, and therefore represents a promising target for vaccine adjuvants. Innovative trehalose-based Mincle agonists with improved pharmacology and potency may prove useful in the development of Th17-mediated adaptive immune responses. Herein, we report on in vitro and in silico investigations of specific Mincle ligand-receptor interactions required for the effective receptor engagement and activation of Th17-polarizing cytokines. Specifically, we employed a library of trehalose benzoate scaffolds, varying the degree of aryl lipidation and regiochemistry that produce inflammatory cytokines in a Mincle-dependent fashion. In vitro interleukin-6 (IL-6) cytokine production by human peripheral blood mononuclear cells (hPBMCs) indicated that the lipid regiochemistry is key to potency and maximum cytokine output, with the tri-substituted compounds inducing higher levels of IL-6 in hPBMCs than the di-substituted derivatives. Additionally, IL-6 production trended higher after stimulation with compounds that contained lipids ranging from five to eight carbons long, compared to shorter (below five) or longer (above eight) carbon chains, across all the substitution patterns. An analysis of the additional cytokines produced by hPBMCs revealed that compound 4d, tri-substituted and five carbons long, induced significantly greater levels of interleukin-1β (IL-1β), tumor necrosis factor- α (TNF-α), interleukin-23 (IL-23), and interferon- γ (IFN-γ) than the other compounds tested in this study. An in silico assessment of 4d highlighted the capability of this analogue to bind to the human Mincle carbohydrate recognition domain (CRD) efficiently. Together, these data highlight important structure-activity findings regarding Mincle-specific cytokine induction, generating a lead adjuvant candidate for future formulations and immunological evaluations.

Intranasal Self-Adjuvanted Lipopeptide Vaccines Elicit High Antibody Titers and Strong Cellular Responses against SARS-CoV-2.

Despite concerted efforts to tackle the COVID-19 pandemic, the persistent transmission of SARS-CoV-2 demands continued research into novel vaccination strategies to combat the virus. In light of this, intranasally administered peptide vaccines, particularly those conjugated to an immune adjuvant to afford so-called "self-adjuvanted vaccines", remain underexplored. Here, we describe the synthesis and immunological evaluation of self-adjuvanting peptide vaccines derived from epitopes of the spike glycoprotein of SARS-CoV-2 covalently fused to the potent adjuvant, Pam2Cys, that targets toll-like receptor 2 (TLR2). When administered intranasally, these vaccines elicited a strong antigen-specific CD4+ and CD8+ T-cell response in the lungs as well as high titers of IgG and IgA specific to the native spike protein of SARS-CoV-2. Unfortunately, serum and lung fluid from mice immunized with these vaccines failed to inhibit viral entry in spike-expressing pseudovirus assays. Following this, we designed and synthesized fusion vaccines composed of the T-cell epitope discovered in this work, covalently fused to epitopes of the receptor-binding domain of the spike protein reported to be neutralizing. While antibodies elicited against these fusion vaccines were not neutralizing, the T-cell epitope retained its ability to stimulate strong antigen-specific CD4+ lymphocyte responses within the lungs. Given the Spike(883-909) region is still completely conserved in SARS-CoV-2 variants of concern and variants of interest, we envision the self-adjuvanting vaccine platform reported here may inform future vaccine efforts.

Experimental Vitamin D Deficiency in Rats: Clinical Chemistry, Histopathological, and Immunological Evaluation.

Vitamin D deficiency is a significant global health concern. Experimental models are essential to elucidate the biochemical, histopathological, and immunological consequences of this deficiency. This study established a vitamin D deficiency rat model to mimic insufficient vitamin D intake and examine the resulting health impacts, particularly on liver, kidney, and immune functions. Sprague-Dawley male rats were randomly assigned to two groups. The control group received a standard rodent diet, while the experimental group was fed a modified diet with reduced vitamin D for three months. Analyses included serum vitamin D levels, clinical chemistry, renal and liver histopathology, and blood immunophenotyping and cytokine analysis for both the control (n=7) and experimental (n=7) groups. Serum vitamin D 25-OH levels were threefold lower in the experimental group (p < 0.001), indicating the induction of vitamin D deficiency. No significant differences in weight gain were observed between the groups. All clinical chemistry parameters remained within reference ranges. However, the experimental group showed significant declines in triglycerides (TG, p=0.0441), alkaline phosphatase (ALP, p=0.0021), and alanine aminotransferase (ALT, p=0.0002). Histopathology revealed normal liver and kidney architecture in the control group, while the experimental group exhibited hepatic cord deterioration, severe vacuolization in the liver, and edema and dilatation in the renal cortex tubular epithelium. Immunophenotyping analysis of lymphocyte subsets and assessment of serum cytokines did not reveal any differences between the two groups. A vitamin D deficiency model without complications such as obesity, parathyroid issues, or mortality was established in rats. This method could be applied in specific disease experimental models.

The immunological and pharmacokinetic evaluation of Lipid-PLGA hybrid nanoparticle-based oxycodone vaccines

The current opioid epidemic is one of the most profound public health crises facing the United States. Despite that it has been under the spotlight for years, available treatments for opioid use disorder (OUD) and overdose are limited to opioid receptor ligands such as the agonist methadone and the overdose reversing drugs such as naloxone. Vaccines are emerging as an alternative strategy to combat OUD and prevent relapse and overdose. Most vaccine candidates consist of a conjugate structure containing the target opioid attached to an immunogenic carrier protein. However, conjugate vaccines have demonstrated some intrinsic shortfalls, such as fast degradation and poor recognition by immune cells. To overcome these challenges, we proposed a lipid-PLGA hybrid nanoparticle (hNP)-based vaccine against oxycodone (OXY), which is one of the most frequently misused opioid analgesics. The hNP-based OXY vaccine exhibited superior immunogenicity and pharmacokinetic efficacy in comparison to its conjugate vaccine counterpart. Specifically, the hNP-based OXY vaccine formulated with subunit keyhole limpet hemocyanin (sKLH) as the carrier protein and aluminum hydroxide (Alum) as the adjuvant (OXY-sKLH-hNP(Alum)) elicited the most potent OXY-specific antibody response in mice. The induced antibodies efficiently bound with OXY molecules in blood and suppressed their entry into the brain. In a following dose-response study, OXY-sKLH-hNP(Alum) equivalent to 60 μg of sKLH was determined to be the most promising OXY vaccine candidate moving forward. This study provides evidence that hybrid nanoparticle-based vaccines may be superior vaccine candidates than conjugate vaccines and will be beneficial in treating those suffering from OUD.

Extracellular vesicles from the microalga Tetraselmis chuii are biocompatible and exhibit unique bone tropism along with antioxidant and anti-inflammatory properties

Extracellular vesicles (EVs) are membrane-enclosed bio-nanoparticles secreted by cells and naturally evolved to transport various bioactive molecules between cells and even organisms. These cellular objects are considered one of the most promising bio-nanovehicles for the delivery of native and exogenous molecular cargo. However, many challenges with state-of-the-art EV-based candidates as drug carriers still exist, including issues with scalability, batch-to-batch reproducibility, and cost-sustainability of the final therapeutic formulation. Microalgal extracellular vesicles, which we named nanoalgosomes, are naturally released by various microalgal species. Here, we evaluate the innate biological properties of nanoalgosomes derived from cultures of the marine microalgae Tetraselmis chuii, using an optimized manufacturing protocol. Our investigation of nanoalgosome biocompatibility in preclinical models includes toxicological analyses, using the invertebrate model organism Caenorhabditis elegans, hematological and immunological evaluations ex vivo and in mice. We evaluate nanoalgosome cellular uptake mechanisms in C. elegans at cellular and subcellular levels, and study their biodistribution in mice with accurate space-time resolution. Further examination highlights the antioxidant and anti-inflammatory bioactivities of nanoalgosomes. This holistic approach to nanoalgosome functional characterization demonstrates that they are biocompatible and innate bioactive effectors with unique bone tropism. These findings suggest that nanoalgosomes have significant potential for future therapeutic applications.

Preparation and immunological activity evaluation of an intranasal protein subunit vaccine against ancestral and mutant SARS-CoV-2 with curdlan sulfate/O-linked quaternized chitosan nanoparticles as carrier and adjuvant

Chitosan and its derivatives are ideal nasal vaccine adjuvant to deliver antigens to immune cells. Previously, we successfully used a chitosan derivative, O-(2-Hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (O-HTCC), and a β-glucan derivative, curdlan sulfate (CS), to prepare a nanoparticle adjuvant CS/O-HTCC which could deliver ovalbumin to antigen presenting cells (APCs) through nasal inhalation. In this article, we used SARS-CoV-2 spike receptor binding domain (S-RBD) as the antigen and CS/O-HTCC nanoparticles as the adjuvant to develop a nasal mucosal protein subunit vaccine, CS/S-RBD/O-HTCC. The humoral immunity, cell-mediated immunity and mucosal immunity induced by vaccines were evaluated. The results showed that CS/S-RBD/O-HTCC could induce desirable immunization with single or bivalent antigen through nasal inoculation, giving one booster vaccination with mutated S-RBD (beta) could bring about a broad cross reaction with ancestral and different mutated S-RBD, and vaccination of the BALB/c mice with CS/S-RBD/O-HTCC containing S-RBD mix antigens (ancestral and omicron) could induce the production of binding and neutralizing antibodies against both of the two antigens. Our results indicate that CS/O-HTCC is a promising nasal mucosal adjuvant to prepare protein subunit vaccine for both primary and booster immunization, and the adjuvant is suitable for loading more than one antigen for preparing multivalent vaccines.

Quantitative indicators of TREC and KREC excision circles in malignancies: a prospective cohort study

Background. In oncology, of particular interest is the study of the T-cell receptor excision circles (TREC) and the κ-deletion B-cell receptor excision circles (KREC), which are extrachromosomal DNA structures. In many malignancies, the effectiveness of immune checkpoint inhibitors depends on the mutational load of the tumor, which correlates with the formation of specific antitumor immunity. Quantitative indicators of recombination excision circles reflect the occurrence of a different repertoire of T-cell receptors, an integral component in the formation of specific immunity. Understanding the change in quantitative values of TREC and KREC in cancer patients can improve the selection of patients for immunotherapy. Aim. To determine quantitative indicators of TREC and KREC for immunological evaluation of patients with malignancies. Materials and methods. The study included 55 healthy individuals and 180 patients with malignancies. Among healthy individuals, 49.1% (27/55) were males and 50.9% (28/55) females. Among patients with malignancies, 20.5% (37/180) were males and 79.5% (143/180) females. The median age in healthy individuals was 36 years [Q1–Q3: 26–58]. The median age in the group of patients with malignancies was 57 years [Q1–Q3: 47.5–67]. Results. In the general population of healthy individuals, the median TREC level was 60.1 [Q1-Q3: 31.3-188.9] and the median KREC level was 256 [Q1-Q3: 149.8-353]. In the general population of patients with malignancies, the median TREC rate was 4.6 [Q1-Q3: 0.9-17.3] and the median KREC was 111.9 [Q1-Q3: 29.3-339.28]. According to the results of the study, we noted statistically significant differences in TREC and KREC indices between all patients with malignancies and healthy individuals (p0.001, p=0.001). Analysis of TREC and KREC indices in patients with malignancies of various localizations (breast cancer, ovarian cancer, lung cancer, colorectal cancer, skin melanoma, lymphomas) in comparison with healthy individuals statistically significant differences in TREC level were noted (p=0.001, p0.001). When analyzing the KREC level in the studied groups, statistically significant differences in patients with ovarian malignancies (p0.001), lymphoma (p0.001), colorectal cancer (p=0.001) and melanoma (p=0.039) in comparison with healthy individuals were obtained. When comparing groups pairwise, it was found that TREC level in patients with malignancies in the age group of 25–44 years was significantly higher than in the age group of 45–60 years (p=0.03); TREC level in the age group of 25–44 years was significantly higher than in the age group of persons over 60 years (p0.001); TREC level in the age group of 45–60 years was significantly higher than in the age group over 60 years (p0.001). Statistically significant differences of KREC level in the studied patients with malignancies depending on the age group were not established (p=0.16), there were no age differences of groups by KREC level. Conclusion. The results demonstrate a significant decrease in TREC and KREC levels in patients with malignancies compared to healthy individuals. The study of TREC and KREC excision circles in peripheral blood is one of the promising approaches for the immunological evaluation of cancer patients.

Genetic polymorphism and immunological evaluation of PD-1 in Iraqi patients with acute myeloid leukemia.

PD-1 has a noteworthy function in developing acute myeloid leukemia (AML). The expression of PD-1 on effector T cells is regulated at the protein level depending on the interactions between cells. The objective of the study was to evaluate the PD-1 concentration levels and the polymorphism genetic variants (rs36084323 G/A) in Iraqi Arab patients with AML. Sanger's DNA sequencing was used, and the assessments were done by enzyme-linked immunosorbent assay and PD-1 gene polymorphism SNP rs36084323 G/A. The frequency of rs36084323 was significantly different between AML and control, with a lower risk for AML seen in patients with GA genotype (odds ratio; 95% confidence interval: 0.53; 0.32-0.87). PD-1 elevated AML compared to control (213.1 pg/mL vs. 178.8 pg/mL). in AML patients, there is upregulation in PD-1, which indicates that PD-1 is a possible biomarker for AML. PD-1 rs36084323 G/A may have a role in AML risk.

PDE1B, a potential biomarker associated with tumor microenvironment and clinical prognostic significance in osteosarcoma

PDE1B had been found to be involved in various diseases, including tumors and non-tumors. However, little was known about the definite role of PDE1B in osteosarcoma. Therefore, we mined public data on osteosarcoma to reveal the prognostic values and immunological roles of the PDE1B gene. Three osteosarcoma-related datasets from online websites were utilized for further data analysis. R 4.3.2 software was utilized to conduct difference analysis, prognostic analysis, gene set enrichment analysis (GSEA), nomogram construction, and immunological evaluations, respectively. Experimental verification of the PDE1B gene in osteosarcoma was conducted by qRT-PCR and western blot, based on the manufacturer's instructions. The PDE1B gene was discovered to be lowly expressed in osteosarcoma, and its low expression was associated with poor OS (all P < 0.05). Experimental verifications by qRT-PCR and western blot results remained consistent (all P < 0.05). Univariate and multivariate Cox regression analyses indicated that the PDE1B gene had independent abilities in predicting OS in the TARGET osteosarcoma dataset (both P < 0.05). GSEA revealed that PDE1B was markedly linked to the calcium, cell cycle, chemokine, JAK STAT, and VEGF pathways. Moreover, PDE1B was found to be markedly associated with immunity (all P < 0.05), and the TIDE algorithm further shed light on that patients with high-PDE1B expression would have a better immune response to immunotherapies than those with low-PDE1B expression, suggesting that the PDE1B gene could prevent immune escape from osteosarcoma. The PDE1B gene was found to be a tumor suppressor gene in osteosarcoma, and its high expression was related to a better OS prognosis, suppressing immune escape from osteosarcoma.

Monogenic Inborn Errors of Immunity with impaired IgG response to polysaccharide antigens but normal IgG levels and normal IgG response to protein antigens.

In patients with severe and recurrent infections, minimal diagnostic workup to test for Inborn Errors of Immunity (IEI) includes a full blood count, IgG, IgA and IgM. Vaccine antibodies against tetanus toxoid are also frequently measured, whereas testing for anti-polysaccharide IgG antibodies and IgG subclasses is not routinely performed by primary care physicians. This basic approach may cause a significant delay in diagnosing monogenic IEI that can present with an impaired IgG response to polysaccharide antigens with or without IgG subclass deficiency at an early stage. Our article reviews genetically defined IEI, that may initially present with an impaired IgG response to polysaccharide antigens, but normal or only slightly decreased IgG levels and normal responses to protein or conjugate vaccine antigens. We summarize clinical, genetic, and immunological findings characteristic for these IEI. This review may help clinicians to identify patients that require extended immunologic and genetic evaluations despite unremarkable basic immunologic findings. We recommend the inclusion of anti-polysaccharide IgG antibodies as part of the initial routine work-up for possible IEI.