Serum Clusterin Concentration and Its Glycosylation Changes as Potential New Diagnostic Markers of SARS-CoV-2 Infection and Recovery Process

COVID-19 is an infectious disease caused by the SARS-CoV-2 virus. Glycoprotein clusterin (CLU) has many functions such as phagocyte recruitment, complement system inhibition, apoptosis inhibition, hormone and lipid transport, as well as in the immune response. The study aimed to assess the changes in CLU concentrations and the profile and degree of CLU glycosylation between patients with severe COVID-19, convalescents, and healthy subjects (control). The profile and degree of serum CLU N-glycosylation were analyzed using lectin-ELISA with specific lectins. CLU concentrations were significantly lower and relative reactivities of CLU glycans with SNA (Sambucus nigra agglutinin) were significantly higher in severe COVID-19 patients in comparison to convalescents and the control group. The relative reactivities of CLU glycans with MAA (Maackia amurensis agglutinin), together with relative reactivity with LCA (Lens culinaris agglutinin), were also significantly higher in patients with severe COVID-19 than in convalescents and the control group, but they also significantly differed between convalescents and control. The development of acute inflammation in the course of severe COVID-19 is associated with a decrease in CLU concentration, accompanied by an increase in the expression of α2,3-linked sialic acid, and core fucose. Both of these parameters can be included as useful glycomarkers differentiating patients with severe COVID-19 from convalescents and the control group, as well as convalescents and healthy subjects.

Are Changes in Serum IgG Glycosylation Related to the Severe Course of SARS-CoV-2 Infection and Recovery Process? In Search of New Diagnostic and Prognostic Biomarkers

Introduction

Immunoglobulin G (IgG) glycosylation affects its effector functions and is essential in many steps of the inflammatory cascade. Therefore, it may be an important parameter for assessing the body's immune response during the course of COVID-19 (Coronavirus disease 2019).

Methods

The N- and O-glycosylation of serum IgG in severe COVID-19 patients (n=87), convalescents (n=50), and healthy subjects (n=65) were examined using a modified lectin-ELISA method with specific biotinylated lectins. The obtained data were analyzed using STATISTICA 13.3PL software.

Results

We showed significantly higher expression of Lewisx oligosaccharide structures in severe COVID-19 patients than in the other two groups. Moreover, significantly lower expression of Lewisy sugar structures in IgG glycans was observed in the convalescents when compared with COVID-19 patients and healthy subjects. The lowest expression of highly branched N-glycans in cases of severe COVID-19 indicates that the development of the disease is associated with the presence of typical IgG biantennary N-glycans. The lack of significant differences in the expression of Tn antigen in IgG between studied groups and the significantly lower expression of T antigen in convalescents compared to the patients with severe COVID-19 and healthy subjects indicates a decrease in the content of the T antigen in IgG O-glycans in subjects recovered from COVID-19. Substantially higher reactivities of IgG O-glycans with Jacalin observed in COVID-19 patients and convalescents in comparison to the control group were most probably caused by increased expression of core 3 O-glycans in IgG.

Conclusion

Severe COVID-19 is accompanied by the expression in serum IgG of sialylated biantennary and highly branched N-glycans, decorated by fucose of Lewisx and Lewisy structures. The higher reactivity of IgG O-glycans with Jacalin in severe COVID-19 patients and convalescents indicates that the disease development and the recovery process are most probably accompanied by increased expression of the core 3 O-glycans.

GC-MS analysis of the composition of serum IgG glycans as a potential diagnostic marker of advanced endometriosis - Preliminary report

BACKGROUND

Endometriosis is an immune-mediated inflammatory disease that causes the growth of endometrial-like tissue outside the uterus. Diagnostics of this disease are difficult, often invasive, and time-consuming, therefore non-invasive diagnostic methods and parameters are very desirable in endometriosis detection.

OBJECTIVES

The study aimed to check whether there are any differences in the monosaccharide composition of N-glycans in serum IgG of women with advanced endometriosis and women with mild gynecological diseases.

MATERIALS AND METHODS

The study material consisted of IgG samples isolated from blood sera derived from patients diagnosed with advanced endometriosis and women without endometriosis but with other gynecological diseases. To determine the monosaccharide composition of N-glycans in IgG, the gas chromatography-mass spectrometry (GC-MS) method was used.

RESULTS

It was observed a significantly higher content of GlcNAc in the group of women with mild gynecological diseases, compared to the group of patients with advanced endometriosis (6.5 ± 5.2 and 4.5 ± 5.7; p = 0.0007704, respectively). In addition, the content of fucose was significantly higher in the group of women with mild gynecological diseases compared to women with advanced endometriosis (1.9 ± 0.5 and 1.7 ± 1.2; p = 0.000274, respectively).

CONCLUSIONS

The content of GlcNAc and fucose in serum IgG may be useful markers differentiating patients with advanced endometriosis from women without endometriosis but with mild gynecological diseases.

O-Glycosylation Changes in Serum Immunoglobulin G Are Associated with Inflammation Development in Advanced Endometriosis

Endometriosis is a gynecological disease, the pathogenesis of which seems to be directly related to inflammatory processes with an immune basis. Our study aimed to analyze the O-glycosylation of native serum IgG and IgG isolated from sera of women with advanced endometriosis, without endometriosis but with benign gynecological diseases, and from a control group of healthy women, in the context of its utility for differentiation of advanced endometriosis from the other two groups of women studied. For the analysis of serum IgG O-glycosylation and the expression of multi-antennary N-glycans, lectin-ELISA with lectins specific to O-glycans (MPL, VVL, and Jacalin) and highly branched N-glycans (PHA-L) was used. The relative reactivities of isolated serum IgG O-linked glycans with specific lectins as well as the MPL/VVL O-glycosylation ratio were significantly higher in patients with advanced endometriosis and those with other gynecological diseases when compared to the control group of healthy women. We also showed significantly higher expression of PHA-L-reactive multi-antennary N-glycans in isolated IgG in the advanced endometriosis and the non-endometriosis groups in comparison to the control group. Additionally, significantly higher expression of Jacalin-reactive O-glycans in isolated IgG was observed in the non-endometriosis than in the advanced endometriosis group. The results of the ROC curve and cluster analysis additionally confirmed that the lectin-based analysis of isolated serum IgG O-glycosylation and the expression of highly branched N-glycans may help distinguish women with advanced endometriosis from healthy women. Moreover, the analysis of the expression of Jacalin-reactive i-IgG O-glycans may be helpful in differentiation between women with advanced endometriosis and patients with other gynecological diseases with an inflammatory background. In the case of non-endometriosis patients, the observed differences were most probably caused by increased expression of core 3 type O-glycans.

The Alterations of Serum IgG Fucosylation as a Potential Additional New Diagnostic Marker in Advanced Endometriosis

BACKGROUND

Endometriosis is an inflammatory disease leading to the growth of endometrial-like tissue outside of the uterus, which affects approximately 10% of young women of reproductive potential. The diagnosis of this disease is difficult, often invasive and time-consuming, therefore non-invasive diagnostic methods are strongly desirable in endometriosis detection. The aim of our project was to investigate whether any associations exist between the expression of serum IgG fucosylation and advanced stages of endometriosis. We were also interested in whether native serum IgG (s-IgG) fucosylation analysis, without prior IgG isolation, could provide a panel of parameters helpful in non-invasive diagnostics of advanced endometriosis.

METHODS

IgG fucosylation was examined using a lectin-ELISA test with fucose-specific lectins: AAL and LCA, specific for core fucose α1,6-linked, as well as LTA and UEA which recognize α1,3- and α1,2-linked fucose, respectively.

RESULTS

ROC curve and cluster analysis showed s-IgG reactivities with the panel of fucose-specific lectins AAL, LCA and LTA.

CONCLUSION

s-IgG reactivity with the panel of fucose-specific lectins AAL, LCA and LTA can be taken into account as a useful diagnostic and clinical tool to differentiate women with advanced endometriosis. Moreover, it has been shown that the analysis of native IgG fucosylation directly in serum, without prior time-consuming, expensive IgG isolation, is sufficient to distinguish advanced stages of endometriosis from a control group of healthy women.

Variability of serum IgG sialylation and galactosylation degree in women with advanced endometriosis

Endometriosis is an inflammatory disease which diagnostics is difficult and often invasive, therefore non-invasive diagnostics methods and parameters are needed for endometriosis detection. The aim of our study was to analyse the glycosylation of native serum IgG and IgG isolated from sera of women classified as: with endometriosis, without endometriosis but with some benign ginecological disease, and control group of healthy women, in context of its utility for differentiation of advanced endometriosis from the group of healthy women. IgG sialylation and galactosylation/agalactosylation degree was determined using specific lectins: MAA and SNA detecting sialic acid α2,3- and α2,6-linked, respectively, RCA-I and GSL-II specific to terminal Gal and terminal GlcNAc, respectively. The results of ROC and cluster analysis showed that the serum IgG MAA-reactivity, sialylation and agalactosylation factor may be used as supplementary parameters for endometriosis diagnostics and could be taken into account as a useful clinical tool to elucidate women with high risk of endometriosis development. Additionally, we have shown that the analysis of native serum IgG glycosylation, without the prior time-consuming and expensive isolation of the protein, is sufficient to differentiation endometriosis from a group of healthy women.

Sirtuins: Enzymes with multidirectional catalytic activity

Sirtuins (SIRT) are NAD+-dependent histone deacetylases that play an important role in the functioning of the human body. They participate in numerous processes taking place in cells, including in the post-translational modification of proteins, silencing gene transcription, inducing repair processes, as well as in the regulation of metabolic processes. Sirtuins have also been shown to play an important role in reducing the level of reactive oxygen species as well as in stimulating cell growth, aging and death. Such a wide range of processes, which are affected by sirtuins, have recently made sirtuins the object of many studies aimed at a detailed understanding of the mechanisms of their action and the role they play. The aim of our study was to collect and systematize information on sirtuins, mainly from the last 10 years, both regarding the human body and based on the results of research on animal models or cell lines. The article discusses the structure, function and biological role of sirtuins in cellular processes.

Diagnostic Significance of Selected Serum Inflammatory Markers in Women with Advanced Endometriosis

Endometriosis is a gynecological disease, the pathogenesis of which seems to be directly associated with inflammatory processes. Serum concentrations of IL-1β, IL-6, hs-CRP, IgG, YKL 40 and PRL, in comparison to the well-known CA 125 levels, were studied with the aim of identifying an additional noninvasive inflammatory marker or set of markers characteristic for endometriosis. The study group included 43 women with endometriosis (E), 35 women with benign gynecological disorders but without endometriosis (NE, non-endometriosis) as a comparative group, and a control group consisting of 18 healthy subjects (C). The serum concentrations of IL-1β, IL-6, hs-CRP, YKL-40, PRL and CA 125 were significantly higher in the E group (median values: 0.41 pg/mL, 2.42 pg/mL, 2.33 mg/L, 79.30 ng/mL, 21.88 ng/mL and 68.00 U/mL, respectively) than in the control group (median values: 0.21 pg/mL, 0.98 pg/mL, 0.52 mg/L, 49.77 ng/mL, 12.08 ng/mL and 12.20 U/mL respectively), with the significance of p = 0.011, p < 0.001, p = 0.028, p = 0.005, p < 0.001 and p < 0.001, respectively. The IgG concentrations were significantly lower in the endometriosis group (median value: 1061.21 mg/dL) as compared to healthy women (median value: 1210.50 mg/dL; p = 0.025). Significant differences in concentrations of IL-6 (p = 0.040), hs-CRP (p = 0.007) and CA 125 (p < 0.001) were observed in stage III vs. stage IV of endometriosis. Significantly higher concentrations of IL-6 (p = 0.010), hs-CRP (p = 0.037) and PRL (p < 0.001) were observed in the NE group vs. the control group. Only CA 125 concentrations were significantly higher in endometriosis patients as compared to the non-endometriosis group (p < 0.001). The proposed panel of inflammatory markers, especially IL-6, PRL and CA 125, may become a useful tool to identify women with advanced endometriosis who could qualify for treatment.

Sirtuins as Important Factors in Pathological States and the Role of Their Molecular Activity Modulators

Sirtuins (SIRTs), enzymes from the family of NAD⁺-dependent histone deacetylases, play an important role in the functioning of the body at the cellular level and participate in many biochemical processes. The multi-directionality of SIRTs encourages scientists to undertake research aimed at understanding the mechanisms of their action and the influence that SIRTs have on the organism. At the same time, new substances are constantly being sought that can modulate the action of SIRTs. Extensive research on the expression of SIRTs in various pathological conditions suggests that regulation of their activity may have positive results in supporting the treatment of certain metabolic, neurodegenerative or cancer diseases or this connected with oxidative stress. Due to such a wide spectrum of activity, SIRTs may also be a prognostic markers of selected pathological conditions and prove helpful in assessing their progression, especially by modulating their activity. The article presents and discusses the activating or inhibiting impact of individual SIRTs modulators. The review also gathered selected currently available information on the expression of SIRTs in individual disease cases as well as the biological role that SIRTs play in the human organism, also in connection with oxidative stress condition, taking into account the progress of knowledge about SIRTs over the years, with particular reference to the latest research results.

The Influence of Serum Sample Storage Conditions on Selected Laboratory Parameters Related to Oxidative Stress: A Preliminary Study

The present work aims at accessing the stability of biological material stored for diagnostic and scientific purposes. The influence of the temperature, storage time, and cyclic thawing on concentration stability of selected oxidative stress parameters in human serum was investigated. The study group consisted of 20 serum samples collected from healthy volunteers aged 18–52. The parameters whose reference ranges were not determined and to which validated determination methods did not correspond were examined by manual methods (FRAP and AOPP). Automatic methods were used to determine routine laboratory tests (albumin, total protein, bilirubin, uric acid) using the Konelab 20i^® analyzer. The samples were stored at various temperatures (room temperature, 4 °C, −20 °C, −80 °C) for max 6 months and were subjected to cyclic thawing at 1 month intervals. In order to check whether any differences between the concentrations of the studied parameters existed when the samples were stored in various conditions, the paired Student t-test or Wilcoxon test and comparison to desirable bias were applied. Based on the obtained results, it was found that the temperature and time of serum sample storage significantly affected the stability of the analyzed parameters and determined different shelf lives of serum samples for oxidative stress examination. Therefore, continuing the investigation concerning the impact of storage conditions on various serum parameters seems justified due to the discrepancy between the individual results obtained by different researchers and the inconsistencies between the results of scientific research and the applicable recommendations.

[Erythropoietin and blood loss in selected orthopedic procedures]

Orthopedic surgical procedures, especially in the lower limbs, are associated with a high risk of massive bleeding and, consequently, the development of anemia and the need for blood transfusions and its preparations. This creates the need to look for effective methods of prevention and treatment of anemia that will be safe for the patient and reduce the cost of treatment. One of the most common methods of limiting the allogenic blood usage in orthopedic procedures is the use of autologus transfusions. In addition to many benefits, they may contribute to the patient's anemia, which is a serious health problem in the post-operative period. Analyzed data from the literature indicate that the use of recombinant human erythropoietin significantly reduces the need for blood transfusion in the perioperative period and may reduce the cost of treatment.