Recent advances in understanding the pathogenesis and biological treatment of multiple sclerosis.

Multiple sclerosis is the most common demyelinating disease that develops in genetically predisposed individuals through various immunopathological mechanisms induced by environmental factors, especially viral infections. Th1, Th17, γδ T cells, activated macrophages, MAIT cells, and proinflammatory cytokines, particularly IFN-γ, TNF, IL-17, and GM-CSF, are the principal pathological players whose activities cause damage to the white matter. Furthermore, a recently identified subset of CD4+ T cells has been found to migrate directly to the brain cortex and cause damage to neurons. In 2022, a new mechanism was discovered in addition to these processes. It was shown that molecular mimicry between the EBNA-1 antigen of the Epstein-Barr virus and the GlialCAM molecule of glial cells forms the basis that triggers the entire pathological process. EBV is a highly B cell-tropic human herpesvirus that placed B cells at the centre of our attention. As a result, we must down-regulate their numbers using anti-CD20 monoclonal antibodies to treat such patients (Tab. 1, Fig. 1, Ref. 37). Keywords: multiple sclerosis, GlialCAM, HLA-DR15, T-, B-, MAIT-cells, EBV, monoclonal antibodies.

HMGB1 as a potential new marker of disease activity in patients with multiple sclerosis.

OBJECTIVES: Neuroinflammation represents one of the two major pathological components of multiple sclerosis (MS). The aim of our study was to find the role of the late pro-inflammatory cytokine HMGB1 (high mobility group box) in MS pathogenesis. SUBJECTS AND METHODS: A total of 165 patients from three MS centers in Slovakia were enrolled in the study. Patients underwent a complex clinical investigation and their plasma levels of HMGB1 were analyzed by a sandwich ELISA test. RESULTS: MS patients had 4.5 times higher plasma level of HMGB1 (median, 13.529 ng/mL; IQR = 2.330-113.45) than healthy controls (median, 2.999 ng/mL; IQR = 1.686-9.844; P < 0.0001). The concentrations of HMGB1 were significantly associated with increased number of affected areas diagnosed by MRI (P < 0.0001) (the median for one affected area, 4.205 ng/mL; median for five affected areas, 17.843 ng/mL; P < 0.05). Patients with at least one active lesion in any of the affected areas in the brain had significantly higher plasma levels of HMGB1 (median, 20.118 ng/mL; IQR, 3.693-100.12) than those without any active lesion (median, 16.695 ng/mL; IQR, 3.255-113.45; P < 0.0235). We found also a very highly significant association of HMGB1 plasma levels with clinical condition expressed as EDSS (expanded disability status scale) (P < 0.0001); patients with higher EDSS had higher levels of HMGB1 (EDSS ≤ 2.5, 11.648 ng/mL vs. EDSS ≥ 3, 17.549 ng/mL; P = 0.0115). CONCLUSION: Our results suggest chronic low-grade inflammation in MS patients that correlates with clinical conditions of MS patients, and for HMGB1 as a possible target molecule in future therapy.

Association of HLA-G Polymorphisms in the 3'UTR Region and Soluble HLA-G with Kidney Graft Outcome.

Background: Human leukocyte antigen G (HLA-G) belongs to nonclassical HLA I molecule involving in the suppression of immune response. Besides its profound effect to induce fetal tolerance, HLA-G expression has been associated with allograft acceptance. For the regulation of HLA-G levels, polymorphic sites within the 3' untranslated region (3'UTR) are of crucial importance. The aim of the study was to analyze the association between several HLA-G 3'UTR variants (+3003T/C, +3010C/G, +3027C/A, +3035C/T, +3142G/C, +3187A/G, and +3196C/G), soluble HLA-G (sHLA-G) level, and kidney graft outcome in the Slovak Caucasian population. Methods: We investigated 69 kidney transplant recipients (45 males, 24 females) of age 27-65 years. Out of this group, 37 recipients developed acute rejection that was biopsy proven. Recipient's plasma was obtained at 1 day before transplantation and analyzed by ELISA. The HLA-G 3'UTR polymorphisms were typed by direct sequencing. Results: In the recipients with stable allograft function, significantly higher values of sHLA-G were found in the homozygous +3010GG, +3142CC, +3187GG, and +3196CC carriers in comparison to the acute rejection recipients (P = 0.01-0.05). Conclusion: The study demonstrated genetic association between HLA-G 3'UTR variants and sHLA-G level in kidney recipients leading to graft acceptance. We suggest to monitor the pretransplantation sHLA-G level as additional marker to predict kidney graft outcome. Abbreviations: AMR: Antibody-mediated rejection; APC: antigen-presenting cell; CD: cluster of designation; del: deletion; HLA: human leukocyte antigen; ILT: immunoglobulin-like transcript; ins: insertion; KIR: killer-cell immunoglobulin-like receptor; NK: natural killer; sHLA-G: soluble HLA-G; SNP: single nucleotide polymorphism; TCMR: T cell-mediated rejection; URR: upstream regulatory region; UTR: untranslated region.

Heterogeneity of lymphocytes as central operating units of the immune system.

Immune response is divided into natural and adaptive although such strict division is rather contentious as one type of immunity influences another one and vice-versa; moreover, there are cells and immune mechanisms, which stay somewhere in an interface. B and T lymphocytes represent principal cells of adaptive immunity. Not one of them form a uniform population. B cells comprise of three subpopulations (follicular, B1, marginal zone). Concerning T cells, the situation is more complicated. There are two basic populations, that expressing T cell receptors α, β and that expressing γ, δ receptors. T cells αβ are very heterogeneous; we can distinguish helper, cytotoxic and regulatory cells. Moreover, among T helper cell, are there seven subsets. Except the above-mentioned effector B and T cells, each group has its counterpart in the form of memory cells, wherein the memory T cell are of three types. The other group of lymphocytes represent so-called unconventional cells. NK, NKT a MAIT are their representatives; they are also heterogeneous. Ultimately, a novel group of cells appeared recently. It stays just on the interphase between natural and adaptive immunity. We know these cells under the name innate lymphoid cells (ILCs). They are also not uniform - three basic populations are well characterized: ILC1, ILC2, ILC3. Moreover, in the frame of each family, we can distinguish more subsets. Enumeration of said cell types indicates complexity and mutual interconnection of immune processes in order to maintain biological integrity of an individual.

[Current and prospective biologics and small molecules in the treatment of inflammatory bowel diseases]. / Súcasné a perspektívne biologiká a malé molekuly v liecbe idiopatických zápalových chorôb creva.

Crohns disease (CD) and ulcerative colitis (UC) belong to chronic inflammatory bowel diseases, which are induced by autoimmune processes. While CD is characterized by over-activity of Th1, ILC1, and MAIT cells, UC is mediated by exaggerated activities of Th2 and ILC2 cells and cytokines they produce. Knowledge of the pathogenesis enabled a rational therapy based mostly on biologics and small molecules. TNF is the principal proinflammatory cytokine in both diseases. Anti-TNF monoclonal antibodies, mostly infliximab or adalimumab were therefore introduced to their treatment. Approximately 50-70 % of CD and more than 33 % of UC patients respond to primary treatment only, which resulted in the development of other biologics and small molecules. Out of them, monoclonal antibodies targeting adhesive molecules (vedolizumab, etrolizumab) and p40 chains shared by IL12 and IL23 (ustekinumab) have been already in clinical practice. There are also other small molecules in clinical trials: mongersen, tafacitinib, and ozanimod. Mongersen supports immunosuppressive activity of TGFß; it has been tried for the treatment of CD. Tofacitinib inhibits activity of JAK kinases; it was shown to be effective in UC management. Ozanimod interferes with migrations of activated T cells to the site of inflammation and is a promising drug for the UC treatment.Key words: Crohns disease - mongersen - monoclonal antibodies - ozanimod - tofacitinib - ulcerative colitis.

Analysis of ICAM1 gene polymorphism in Slovak multiple sclerosis patients.

Infiltration of immune cells into CNS is one of the essential events in multiple sclerosis (MS) development. Adhesion molecules like the intercellular adhesion molecule 1 (ICAM-1) play critical role in this process. Therefore, the ICAM1 gene containing two important single-nucleotide polymorphisms (SNPs) belongs to candidate loci with possible involvement in MS susceptibility and/or severity. The objective of our case-control study was to analyze the association of two functional ICAM1 polymorphisms rs1799969 (or G241R) and rs5498 (or K469E) with susceptibility to MS and evaluate their influence on the age at disease onset, severity, neurological disability and progression rate. Two hundred forty-eight MS subjects (mean 39.2 years) and 208 age-matched controls (mean 35.6 years) were involved in the study. Genotyping of ICAM1 rs1799969 and rs5498 SNPs was performed by PCR-RFLP. Presence of the rs3135388 polymorphism tagging the major MS risk allele HLA-DRB1*15:01 allele was determined as well. Our analysis revealed no statistically significant association of ICAM1 polymorphisms with risk of MS development in the Slovak population. Stratification of study cohorts by gender, age at onset and presence of the HLA-DRB1*15:01 risk allele showed only moderate changes. Correlation of clinical findings as age at onset, Kurtzke Expanded Disability Status Scale, Multiple Sclerosis Severity Score and progression index with ICAM1 genotypes in MS patients revealed no significant association; however, patients with earlier onset of MS showed slightly higher frequencies of the homozygous G allele at rs5498 in comparison to other genotypes (P = 0.04), suggesting that GG carriers tend to induce MS at an earlier age.

The +190 G/A (rs1799864) polymorphism in the C-C chemokine receptor 2 (CCR2) gene is associated with susceptibility to multiple sclerosis in HLA-DRB1*15:01-negative individuals.

C-C chemokine receptor 2 (CCR2) is one of the key players involved in the transmigration of mononuclear cells into the central nervous system (CNS) and subsequent development of multiple sclerosis (MS). The aim of the current study was to analyse the association of CCR2 +190 G/A (rs1799864) polymorphism with susceptibility to MS and its influence on the age at onset, severity and neurological disability in MS. CCR2 genotyping was carried out by a polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP) in 301 MS patients and 342 healthy controls. Logistic regression analysis suggested a marginally significant association between MS and rs1799864 A allele (AA+GA vs. GG, P=0.047, OR=1.50, 95% CI=1.00-2.25), however, after stratification of study groups for the presence of HLA-DRB1*15:01 risk allele, this association could be found in HLA-DRB1*15:01-negative individuals only (AA+GA vs. GG, P=0.014, OR=1.84, 95% CI=1.13-2.98). Furthermore, there was no association between CCR2 polymorphism and clinical features of MS. In conclusion, our results suggest that CCR2 +190 G/A polymorphism may increase the susceptibility to MS, but its action seems to be restricted to individuals who do not possess the major risk allele HLA-DRB1*15:01.

HLA DRB1* and DQB1* alleles are associated with disease severity in patients with pemphigus vulgaris.

BACKGROUND: Pemphigus vulgaris (PV) is a rare autoimmune disease that involves the skin and mucosa. The etiology of PV is multifactorial and includes genetic, environmental, hormonal, and immunological factors. OBJECTIVES: The purpose of this study was to examine the relationships between human leukocyte antigen (HLA) class II alleles associated with PV and variations in the disease phenotype. METHODS: Forty-four PV patients were diagnosed and analyzed at the Bullous Disorders Unit in cooperation with the Institute of Immunology, Faculty of Medicine, Comenius University, Bratislava, Slovakia. HLA class II alleles previously found to be associated with PV (DRB1*04:02, DRB1*04:04, DRB1*14:54, DRB1*14:04, DRB1*14:05, DQB1*03:02 and DQB1*05:03) were analyzed according to disease severity, PV type, and gender distribution. RESULTS: Correlations emerged between PV severity scores and HLA alleles. The DRB1*04:02 and DQB1*03:02 alleles were associated with severe PV (P = 0.001); DRB1*04:02 was associated with the mucocutaneous type (P = 0.024), and DQB1*03:02 was found more frequently in female than in male patients (P = 0.016). Analyses of the other alleles did not reveal significant associations with the clinical parameters evaluated. CONCLUSIONS: The HLA DRB1* and DQB1* alleles influence susceptibility to PV and may contribute to PV severity and type. These results suggest that genetic background may contribute to disease outcome by affecting the disease course and efficacy of treatment because some of the alleles were found significantly more frequently in patients with severe disease.

Association of interleukin-10 gene promoter polymorphisms with susceptibility to acute pyelonephritis in children.

Interleukin-10 (IL-10) is a potent inhibitor of leukocyte chemotaxis, bacterial killing in phagocytes and synthesis of pro-inflammatory cytokines and chemokines, and recent studies have suggested an important role for this immunoregulatory cytokine in the pathogenesis of urinary tract infections (UTIs). Therefore, the gene encoding IL-10 (IL10) is an attractive candidate for association studies attempting to identify susceptibility genes conferring risk of UTIs. In this case-control study, we aimed to investigate the association of single nucleotide polymorphisms (SNPs) in the promoter region of IL10 with acute pyelonephritis in the Slovak population. Polymerase chain reaction with sequence-specific primers was used to analyse IL10 -1082A/G (rs1800896), -819C/T (rs1800871) and -592C/A (rs1800872) SNPs in 147 children with acute pyelonephritis and 215 healthy controls. Comparison of patients with healthy controls using the logistic regression analysis revealed significantly increased risk of developing recurrent attacks of acute pyelonephritis for -1082 G allele in a dominant genetic model GG (GG + AG vs. AA, P = 0.019, odds ratio (OR) = 2.26). A similar tendency was also found when the recurrent acute pyelonephritis subgroup was compared to episodic pyelonephritis cases (GG + AG vs. AA, P = 0.009, OR = 3.38). In conclusion, our results suggest that IL10 -1082 A/G SNP is a susceptibility factor for development of recurrent attacks of acute pyelonephritis.

Donor non-specific MICA antibodies in renal transplant recipients.

Despite recent advances in solid organ transplantations, an antibody mediated rejection caused by donor specific antibodies is still a major problem in kidney graft survival. Besides HLA-induced humoral response, antibodies against MICA antigens have recently attracted attention because of their possible role in graft rejection. The aim of our study was to establish whether renal recipients produce antibodies against MICA molecules due to the transplantation and if they are specific for MICA antigens of the donors. MICA antibody screening was performed in 124 kidney recipient sera. 22 sera, that were found to be MICA antibody positive, were further examined for MICA antibody profiles and compared with donor MICA alleles. The analysis of MICA antibody positive sera showed mostly more complex reactivity patterns. A significant fraction of patient sera (59%) reacted not only with the donor MICA antigens, but also with other MICA patterns. A match between antibody specificities and MICA antigens was observed in 41% of renal recipients only. On the other hand, as much as in 36% of recipient sera were detected antibodies against their own MICA molecules. We did not prove a complete correlation between the recipient MICA antibody specificities and MICA antigens of the donor. We assume that MICA antibody induction occurs not only due to the allogeneic stimulation itself but also due to other factors that need to be elucidated.

Role of regulatory T cells in pathogenesis and biological therapy of multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory disease in which the myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms. It is caused by an autoimmune response to self-antigens in a genetically susceptible individual induced by unknown environmental factors. Principal cells of the immune system that drive the immunopathological processes are T cells, especially of TH1 and TH17 subsets. However, in recent years, it was disclosed that regulatory T cells took part in, too. Subsequently, there was endeavour to develop ways how to re-establish their physiological functions. In this review, we describe known mechanisms of action, efficacy, and side-effects of contemporary and emerging MS immunotherapeutical agents on Treg cells and other cells of the immune system involved in the immunopathogenesis of the disease. Furthermore, we discuss how laboratory immunology can offer physicians its help in the diagnosis process and decisions what kind of biological therapy should be used.

HLA-C, DRB1 and DQB1 alleles involved in genetic predisposition to psoriasis vulgaris in the Slovak population.

Psoriasis vulgaris is a complex chronic skin disease with immunological and genetic background. The most important predisposing genetic factors in psoriasis are genes of the human leukocyte antigen (HLA) region. Accumulative evidence has shown that several HLA alleles are closely associated with psoriasis; however, they tend to vary in different racial and ethnic backgrounds. One hundred forty-seven unrelated Slovak patients with psoriasis vulgaris (average age at onset 28 ± 14 years) were genotyped for the HLA-C, DQB1 and DRB1 alleles by the polymerase chain reaction using sequence-specific primers. Allele frequencies observed in the group of psoriatic patients were compared to those obtained in the ethnically matched control group comprising 194 subjects with no history of psoriasis. Susceptibility to psoriasis vulgaris in our study group is significantly associated with HLA-C*06 (odds ratio (OR) = 3.85), DRB1*07 (OR = 2.56) and DQB1*02 (OR = 1.09), respectively, whereas DRB*01 (OR = 0.05) is associated negatively. Hereby, we provide the first report on the association of HLA-C, DRB1 and DQB1 alleles with psoriasis in the Slovak population. Our findings confirm HLA-C*06 and DRB1*07 as the most important genetic risk factors for psoriasis. However, the role of HLA genes as causative in the pathogenesis of the disease remains unclear. Identification of genetic factors that increase the risk of psoriasis is a precondition that helps to elucidate the pathogenesis of this troubling disease and identify targets for a more specific and effective therapy.

No association between cytokine gene polymorphism and risk of Alzheimer's disease in Slovaks.

Clinical and immunopathological evidence support a potential role of inflammatory cytokines in Alzheimer's disease (AD). However, studies examining the association between cytokine gene polymorphisms and risk of developing AD yielded conflicting results. The objective of our study was to evaluate the association between the functional polymorphisms in the TNF-alpha, TGF-beta1, IL-10, IL-6 and IFN-gamma genes, respectively and the risk of AD in Slovak individuals. Fifty sporadic AD patients and 140 non-demented age-matched control subjects were genotyped in our case-control study. The observed allele and genotype frequencies in AD patients and controls did not reveal any statistically significant differences. In conclusion, our data suggest that there is no involvement of cytokine gene genetic variance in the development of AD in the Slovak population.

Polymorphisms in the genes encoding TGF-beta1, TNF-alpha, and IL-6 show association with type 1 diabetes mellitus in the Slovak population.

Numerous cytokines have been shown to participate in the pathogenesis of type 1 diabetes (T1D). As gene polymorphisms can influence cytokine production or function, they may potentially contribute to genetic predisposition to the disease. The aim of this study was therefore to investigate the role of 22 single nucleotide polymorphisms (SNPs) in 13 cytokine and cytokine receptor genes in genetic susceptibility to T1D. Polymerase chain reaction with sequence-specific primers was used to genotype cytokine SNPs and HLA-DRB1 alleles in 151 diabetics and 140 healthy individuals of Slovak origin. Univariate analysis showed that transforming growth factor (TGF)-beta1 codon 10 TT homozygotes were significantly more susceptible to developing T1D than C allele carriers (P (c) = 0.0066, OR = 2.46). Furthermore, tumor necrosis factor (TNF)-alpha -308 A allele carriers were also significantly overrepresented among the diabetics (P (c) = 0.0031, OR = 2.62); however, the association of the -308 A allele with T1D might be due to its strong linkage disequilibrium with the susceptibility allele HLA-DRB1*0301. An association was also found with interleukin (IL)-6 -174 G/C and nt565 G/A SNPs; however, its significance was lost when statistical correction was applied. These data suggest that the TGF-beta1 codon 10 SNP is among numerous genetic variations with small individual effects on T1D development. Moreover, a possible role of TNF-alpha and IL-6 SNPs cannot be ruled out, although their association with T1D was due to strong LD with the HLA class II susceptibility allele or did not withstand statistical correction, respectively.

Immunopathogenesis of bronchial asthma.

Bronchial asthma is a common immune-mediated disorder characterized by reversible airway inflammation, mucus production, and variable airflow obstruction with airway hyperresponsiveness. Allergen exposure results in the activation of numerous cells of the immune system, of which dendritic cells (DCs) and Th2 lymphocytes are of paramount importance. Although the epithelium was initially considered to function solely as a physical barrier, it is now evident that it plays a central role in the Th2-cell sensitization process due to its ability to activate DCs. Cytokines are inevitable factors in driving immune responses. To the list of numerous cytokines already known to be involved in the regulation of allergic reactions, new cytokines were added, such as TSLP, IL-25, and IL-33. IgE is also a central player in the allergic response. The activity of IgE is associated with a network of proteins, especially with its high- and low-affinity Fc receptors. Understanding the cellular and molecular mechanisms of allergic reactions helps us not only to understand the mechanisms of current treatments, but is also important for the identification of new targets for biological intervention. An IgE-specific monoclonal antibody, omalizumab, has already reached the clinic and similar biological agents will surely follow.

Interleukin 1alpha single-nucleotide polymorphism associated with systemic sclerosis.

OBJECTIVE: In systemic sclerosis (SSc), constitutive expression of the proinflammatory and fibrogenic cytokine interleukin 1alpha (IL-1alpha) by dermal fibroblasts from the affected skin has been observed. We investigated the association of a single-nucleotide polymorphism at position -889 in the IL-1alpha gene in patients with SSc. METHODS: Genotyping of IL-1alpha-889 polymorphism was performed in 46 patients with SSc and in 150 healthy controls by polymerase chain reaction with sequence-specific primers. All subjects were unrelated Slovak Caucasians. RESULTS: In SSc patients, carriers of the IL-1alpha-889 T allele were significantly overrepresented in comparison with controls (63.0% vs 42.0%; p = 0.01, OR 2.3, 95% CI 1.2-4.6). The frequency of the IL-1alpha-889 T allele was increased in SSc patients (38.0%) in comparison with controls (25.7%; p = 0.02). CONCLUSION: The IL-1alpha-889 polymorphism, previously shown to predispose to increased IL-1 protein expression, may be involved in susceptibility to SSc.

Modulation of human lymphocyte proliferation by salivary gland extracts of ixodid ticks (Acari: Ixodidae): effect of feeding stage and sex.

Ixodid ticks remain attached to their hosts for several days to weeks. During this extended feeding process new proteins involved in the modulation of host immune responses are expressed in tick salivary glands. In our study a stimulatory or inhibitory effect of salivary gland extracts (SGE) of unfed and partially fed female Ixodes ricinus (Linnaeus, 1758), female and male Amblyomma variegatum (Fabricius, 1794) and Rhipicephalus appendiculatus Neumann, 1901 ticks on human lymphocyte proliferation induced by Concanavalin A (ConA) and phytohaemagglutinin (PHA), respectively, was investigated. SGE of all female ticks examined suppressed proliferation of ConA-induced lymphocytes; highly significant suppression was observed in the presence of unfed I. ricinus and 9-day fed A. variegatum SGE. SGE of partially fed A. variegatum and I. ricinus females suppressed PHA responses of lymphocytes. Lymphocytes showed reduced PHA and ConA responses in the presence of SGE of unfed and 2-day fed R. appendiculatus females, while SGE of 6-day fed females enhanced PHA responses, but reduced their ConA responses; generally SGE of 2-day fed females displayed the strongest inhibition. Amblyomma variegatum male SGE slightly enhanced PHA, but significantly reduced ConA responses of lymphocytes and their inhibitory effect increased during feeding. SGE of unfed and 2-day fed R. appendiculatus males enhanced PHA and ConA responses and those of 6-day fed males suppressed lymphocyte proliferation. The results suggest that (i) species- and sex-specific differences exist in the effects of tick salivary gland antigens on human lymphocyte proliferation and (ii) effect of SGE on human lymphocyte responses to mitogens varies depending on the tick feeding status.