Browsing by Author "Miljanovic, Danijela (57403944300)"

Nasopharyngeal carcinoma (NPC) is an aggressive tumor with a complex etiology. Although Epstein–Barr virus (EBV) infection is known environmental factor for NPC development, the degree to which EBV naturally infects nasopharyngeal epithelium and the moment when and why the virus actively begins to affect cell transformation remains questionable. The aim of this study was to explore the association between LMP1 gene variability and potential contribution to NPC development. A systematic review was performed through searches of PubMed, Web of Science (WoS) and SCOPUS electronic databases. Additionally, meta-analysis of the difference in the frequency of seven LMP1 gene variants in NPC and control individuals was accomplished. The results from this study give a proof of concept for the association between 30 bp deletion (OR = 3.53, 95% CI = 1.48–8.43) and Xhol loss (OR = 14.17, 95% CI = 4.99–40.20) and NPC susceptibility when comparing biopsies from NPC and healthy individuals. Otherwise, 30 bp deletion from NPC biopsies could not distinguish NPC from EBV-associated non-NPC tumors (OR = 1.74, 95% CI = 0.81–3.75). However, B95-8, China1 and North Carolina variants were uncommon for NPC individuals. Much more efforts remains to be done to verify the biological significance of the differences observed, define so-called “high-risk” EBV variants and make it available for clinical application. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Nasopharyngeal carcinoma (NPC) is an aggressive tumor with a complex etiology. Although Epstein–Barr virus (EBV) infection is known environmental factor for NPC development, the degree to which EBV naturally infects nasopharyngeal epithelium and the moment when and why the virus actively begins to affect cell transformation remains questionable. The aim of this study was to explore the association between LMP1 gene variability and potential contribution to NPC development. A systematic review was performed through searches of PubMed, Web of Science (WoS) and SCOPUS electronic databases. Additionally, meta-analysis of the difference in the frequency of seven LMP1 gene variants in NPC and control individuals was accomplished. The results from this study give a proof of concept for the association between 30 bp deletion (OR = 3.53, 95% CI = 1.48–8.43) and Xhol loss (OR = 14.17, 95% CI = 4.99–40.20) and NPC susceptibility when comparing biopsies from NPC and healthy individuals. Otherwise, 30 bp deletion from NPC biopsies could not distinguish NPC from EBV-associated non-NPC tumors (OR = 1.74, 95% CI = 0.81–3.75). However, B95-8, China1 and North Carolina variants were uncommon for NPC individuals. Much more efforts remains to be done to verify the biological significance of the differences observed, define so-called “high-risk” EBV variants and make it available for clinical application. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Until now, the treatment protocols for COVID-19 have been revised multiple times. The use and approval of therapeutic monoclonal antibodies (mAbs) for COVID-19 treatment represent exceptional achievements in modern science, technology and medicine. SARS-CoV-2 Omicron evasion of pre-existing immunity represents a serious public health problem nowadays. This systematic review with meta-analysis provided comprehensive and up-to-date evidence of the clinical efficacy of therapeutic anti-SARS-CoV-2 mAbs against Omicron subvariants in COVID-19 patients and included 10 articles. The prevalence of hospitalisation among Omicron-positive patients treated with anti-SARS-CoV-2 mAbs was 2.8% (89/3169) while it controls (Omicron-positive patients treated with other therapies) 11% (154/1371). There was a statistically significantly different number of hospitalisations between the two studied groups in favour of the anti-SARS-CoV-2 mAbs treated group. (OR = 0.56, 95% CI OR = 0.41–0.77, p < 0.001, respectively). Eight deaths (0.30%) out of 2619 Omicron-positive patients occurred in the anti-SARS-CoV-2 mAbs treated group, while in the control group (Omicron-positive patients treated with other therapies), 27 patients died out of 1401 (1.93%). There was a significantly different number of deaths between the two studied groups in favour of Omicron-positive patients treated with anti-SARS-CoV-2 mAbs (OR = 0.38, 95% CI OR = 0.17–0.85, p = 0.020). Using sotrovimab in treating Omicron-positive patients indicated a reduction of hospitalisation and mortality for 49% and 89% in favour of sotrovimab, respectively (OR = 0.51, 95% CI OR = 0.34–0.79, p = 0.002; OR = 0.11, 95% CI OR = 0.03–0.39, p = 0.001). We could only provide evidence of the positive impact in reducing hospitalisation and mortality rates when anti-SARS-CoV-2 mAbs were used to treat patients infected with Omicron variants BA.1 or BA.2 and not on other Omicron variants. © 2023 John Wiley & Sons Ltd.

Until now, the treatment protocols for COVID-19 have been revised multiple times. The use and approval of therapeutic monoclonal antibodies (mAbs) for COVID-19 treatment represent exceptional achievements in modern science, technology and medicine. SARS-CoV-2 Omicron evasion of pre-existing immunity represents a serious public health problem nowadays. This systematic review with meta-analysis provided comprehensive and up-to-date evidence of the clinical efficacy of therapeutic anti-SARS-CoV-2 mAbs against Omicron subvariants in COVID-19 patients and included 10 articles. The prevalence of hospitalisation among Omicron-positive patients treated with anti-SARS-CoV-2 mAbs was 2.8% (89/3169) while it controls (Omicron-positive patients treated with other therapies) 11% (154/1371). There was a statistically significantly different number of hospitalisations between the two studied groups in favour of the anti-SARS-CoV-2 mAbs treated group. (OR = 0.56, 95% CI OR = 0.41–0.77, p < 0.001, respectively). Eight deaths (0.30%) out of 2619 Omicron-positive patients occurred in the anti-SARS-CoV-2 mAbs treated group, while in the control group (Omicron-positive patients treated with other therapies), 27 patients died out of 1401 (1.93%). There was a significantly different number of deaths between the two studied groups in favour of Omicron-positive patients treated with anti-SARS-CoV-2 mAbs (OR = 0.38, 95% CI OR = 0.17–0.85, p = 0.020). Using sotrovimab in treating Omicron-positive patients indicated a reduction of hospitalisation and mortality for 49% and 89% in favour of sotrovimab, respectively (OR = 0.51, 95% CI OR = 0.34–0.79, p = 0.002; OR = 0.11, 95% CI OR = 0.03–0.39, p = 0.001). We could only provide evidence of the positive impact in reducing hospitalisation and mortality rates when anti-SARS-CoV-2 mAbs were used to treat patients infected with Omicron variants BA.1 or BA.2 and not on other Omicron variants. © 2023 John Wiley & Sons Ltd.

The present-day management of hepatitis B virus (HBV) infection relies on constant and appropriate monitoring of viral activity, disease progression and treatment response. Traditional HBV infection biomarkers have many limitations in predicting clinical outcomes or therapy success. Quantitation of HBV core antibodies (qAnti-HBc) is a new non-invasive biomarker that can be used in solving multiple diagnostic problems. It was shown to correlate well with infection phases, level of hepatic inflammation and fibrosis, exacerbations during chronic infection and presence of occult infection. Further, the level of qAnti-HBc was recognised as predictive of spontaneous or therapy-induced HBeAg and HBsAg seroclearance, relapse after therapy discontinuation, re-infection after liver transplantation and viral reactivation upon immunosuppression. However, qAnti-HBc cannot be relied upon as a single diagnostic test to solve all dilemmas, and its diagnostic and prognostic power can be much improved when combined with other diagnostic biomarkers (HBV DNA, HBeAg, qHBsAg and anti-HBs antibodies). The availability of commercial qAnti-HBc diagnostic kits still needs to be improved. The comparison of results from different studies and definitions of universal cut-off values continue to be hindered because many methods are only semi-quantitative. The clinical utility of qAnti-HBc and the methods used for its measurement are the focus of this review. © 2023 by the authors.

The present-day management of hepatitis B virus (HBV) infection relies on constant and appropriate monitoring of viral activity, disease progression and treatment response. Traditional HBV infection biomarkers have many limitations in predicting clinical outcomes or therapy success. Quantitation of HBV core antibodies (qAnti-HBc) is a new non-invasive biomarker that can be used in solving multiple diagnostic problems. It was shown to correlate well with infection phases, level of hepatic inflammation and fibrosis, exacerbations during chronic infection and presence of occult infection. Further, the level of qAnti-HBc was recognised as predictive of spontaneous or therapy-induced HBeAg and HBsAg seroclearance, relapse after therapy discontinuation, re-infection after liver transplantation and viral reactivation upon immunosuppression. However, qAnti-HBc cannot be relied upon as a single diagnostic test to solve all dilemmas, and its diagnostic and prognostic power can be much improved when combined with other diagnostic biomarkers (HBV DNA, HBeAg, qHBsAg and anti-HBs antibodies). The availability of commercial qAnti-HBc diagnostic kits still needs to be improved. The comparison of results from different studies and definitions of universal cut-off values continue to be hindered because many methods are only semi-quantitative. The clinical utility of qAnti-HBc and the methods used for its measurement are the focus of this review. © 2023 by the authors.

Real-time reverse transcription polymerase chain reaction (RT-qPCR) is the most sensitive and specific assay and, therefore, is the “gold standard” diagnostic method for the diagnosis of SARS-CoV-2 infection. The aim of this study was to compare and analyze the detection performance of three different commercially available SARS-CoV-2 nucleic acid detection kits: Sansure Biotech, GeneFinder™, and TaqPath™ on 354 randomly selected samples from hospitalized COVID-19 patients. All PCR reactions were performed using the same RNA isolates and one real-time PCR machine. The final result of the three evaluated kits was not statistically different (p = 0.107), and also had a strong positive association and high Cohen’s κ coefficient. In contrast, the average Ct values that refer to the ORF1ab and N gene amplification were significantly different (p < 0.001 and p < 0.001, respectively), with the lowest obtained by the TaqPath™ for the ORF1ab and by the Sansure Biotech for the N gene. The results show a high similarity in the analytical sensitivities for SARS-CoV-2 detection, which indicates that the diagnostic accuracy of the three assays is comparable. However, the SanSure Biotech kit showed a bit better diagnostic performance. Our findings suggest that the imperative for improvement should address the determination of cut-off Ct values and rapid modification of the primer sets along with the appearance of new variants. © 2021 by the authors.

Real-time reverse transcription polymerase chain reaction (RT-qPCR) is the most sensitive and specific assay and, therefore, is the “gold standard” diagnostic method for the diagnosis of SARS-CoV-2 infection. The aim of this study was to compare and analyze the detection performance of three different commercially available SARS-CoV-2 nucleic acid detection kits: Sansure Biotech, GeneFinder™, and TaqPath™ on 354 randomly selected samples from hospitalized COVID-19 patients. All PCR reactions were performed using the same RNA isolates and one real-time PCR machine. The final result of the three evaluated kits was not statistically different (p = 0.107), and also had a strong positive association and high Cohen’s κ coefficient. In contrast, the average Ct values that refer to the ORF1ab and N gene amplification were significantly different (p < 0.001 and p < 0.001, respectively), with the lowest obtained by the TaqPath™ for the ORF1ab and by the Sansure Biotech for the N gene. The results show a high similarity in the analytical sensitivities for SARS-CoV-2 detection, which indicates that the diagnostic accuracy of the three assays is comparable. However, the SanSure Biotech kit showed a bit better diagnostic performance. Our findings suggest that the imperative for improvement should address the determination of cut-off Ct values and rapid modification of the primer sets along with the appearance of new variants. © 2021 by the authors.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. In addition to known risk factors, oncoviruses have attracted exceptional attention from recent research. Numerous hypotheses on interactions between the Epstein–Barr virus (EBV) and Human papillomavirus (HPV) in CRC are still based on sparse prevalence data of these coinfections. The aim of this study was to perform a comprehensive literature search regarding EBV/HPV coinfection in patients with CRC and to provide its prevalence in the target population. Three electronic databases (PubMed, SCOPUS, and WoS) were searched, and after a double reviewer check, six publications were included in the qualitative and quantitative analyses. This systematic review showed the limited number of studies dealing with the prevalence and role of EBV/HPV coinfection in CRC and the heterogeneity of methodology and reported results. However, in a total of 635 patients, it also showed that the identified 15% EBV/HPV prevalence in CRC (15%, 95% CI: 7–23%) could suggest that further investigations are needed. Histopathologically, all coinfected CRCs were adenocarcinomas, from intermediate to intermediate and high grade, reported across four studies. Increased knowledge about the infectious origin of various cancers, including CRC, has the potential to enhance the vigilance of scientists to design future large-scale multicenter prospective studies. © 2024 by the authors.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. In addition to known risk factors, oncoviruses have attracted exceptional attention from recent research. Numerous hypotheses on interactions between the Epstein–Barr virus (EBV) and Human papillomavirus (HPV) in CRC are still based on sparse prevalence data of these coinfections. The aim of this study was to perform a comprehensive literature search regarding EBV/HPV coinfection in patients with CRC and to provide its prevalence in the target population. Three electronic databases (PubMed, SCOPUS, and WoS) were searched, and after a double reviewer check, six publications were included in the qualitative and quantitative analyses. This systematic review showed the limited number of studies dealing with the prevalence and role of EBV/HPV coinfection in CRC and the heterogeneity of methodology and reported results. However, in a total of 635 patients, it also showed that the identified 15% EBV/HPV prevalence in CRC (15%, 95% CI: 7–23%) could suggest that further investigations are needed. Histopathologically, all coinfected CRCs were adenocarcinomas, from intermediate to intermediate and high grade, reported across four studies. Increased knowledge about the infectious origin of various cancers, including CRC, has the potential to enhance the vigilance of scientists to design future large-scale multicenter prospective studies. © 2024 by the authors.

Introduction: The relationship between Systemic lupus erythematosus (SLE) and Epstein-Barr virus (EBV) infection has been suggested for decades, but the underlying mechanism of the EBV influence on SLE development remains to be elucidated. Methods: The goals of this research, which included 103 SLE patients and 99 controls, were to investigate the association of the parameters of EBV infection and SLE, to explore whether pooled demographic, clinical and EBV markers achieve a more significant effect on SLE development than each of them individually, and to evaluate EBV nuclear antigen 1 (EBNA1) and latent membrane protein 1 (LMP1) gene polymorphisms in isolates from SLE patients. Results: Comprehensive results related to serological, molecular and sequence markers of EBV infection in SLE patients demonstrated even 24 times higher possibility of having SLE if there is the presence of anti-EBV-EA(D) (early antigen) IgG antibodies (OR=24.086 95%CI OR=2.86-216.07, p=0.004). There was the same distribution of glucocorticoids (p=0.130), antimalarials (p=0.213), and immunosuppressives (p=0.712) in anti-EBV-EA(D) IgG positive and negative SLE patients. Further, higher anti-EBV-EA(D) IgG antibodies titers were identified as independent factors associated with lymphopenia, hematological SLE manifestation (OR=1.041, 95%CI OR=1.01-1.08, p=0.025, while a higher titer of anti-CA (viral capsid antigen) IgG antibodies (OR=1.015, 95%CI OR=1.01-1.03, p=0.019) and positive RF (rheumatoid factors) (OR=4.871, 95%CI OR=1.52-15.61, p=0.008) were identified as independent factors associated with alopecia within SLE. Finally, novel data on EBV EBNA1 and LMP1 gene polymorphisms in lupus are reported. Conclusion: The results support further investigation targeting EBV as a prognostic marker and therapeutic goal for lupus. Copyright © 2023 Banko, Cirkovic, Miskovic, Jeremic, Grk, Basaric, Lazarevic, Raskovic, Despotovic and Miljanovic.

Introduction: The relationship between Systemic lupus erythematosus (SLE) and Epstein-Barr virus (EBV) infection has been suggested for decades, but the underlying mechanism of the EBV influence on SLE development remains to be elucidated. Methods: The goals of this research, which included 103 SLE patients and 99 controls, were to investigate the association of the parameters of EBV infection and SLE, to explore whether pooled demographic, clinical and EBV markers achieve a more significant effect on SLE development than each of them individually, and to evaluate EBV nuclear antigen 1 (EBNA1) and latent membrane protein 1 (LMP1) gene polymorphisms in isolates from SLE patients. Results: Comprehensive results related to serological, molecular and sequence markers of EBV infection in SLE patients demonstrated even 24 times higher possibility of having SLE if there is the presence of anti-EBV-EA(D) (early antigen) IgG antibodies (OR=24.086 95%CI OR=2.86-216.07, p=0.004). There was the same distribution of glucocorticoids (p=0.130), antimalarials (p=0.213), and immunosuppressives (p=0.712) in anti-EBV-EA(D) IgG positive and negative SLE patients. Further, higher anti-EBV-EA(D) IgG antibodies titers were identified as independent factors associated with lymphopenia, hematological SLE manifestation (OR=1.041, 95%CI OR=1.01-1.08, p=0.025, while a higher titer of anti-CA (viral capsid antigen) IgG antibodies (OR=1.015, 95%CI OR=1.01-1.03, p=0.019) and positive RF (rheumatoid factors) (OR=4.871, 95%CI OR=1.52-15.61, p=0.008) were identified as independent factors associated with alopecia within SLE. Finally, novel data on EBV EBNA1 and LMP1 gene polymorphisms in lupus are reported. Conclusion: The results support further investigation targeting EBV as a prognostic marker and therapeutic goal for lupus. Copyright © 2023 Banko, Cirkovic, Miskovic, Jeremic, Grk, Basaric, Lazarevic, Raskovic, Despotovic and Miljanovic.

Objectives: Epstein-Barr virus (EBV) has been associated with several types of cancers, most often with nasopharyngeal carcinomas and hematological malignancies. It is also suggested that EBV has significant role in the pathogenesis of different types of autoimmune diseases including systemic lupus erythematosus (SEL). The exact mechanisms behind these processes are not elucidated. Case presentation: We present a case of a 52-years old female patients with moderately active SLE presenting with severe fatigue, purpuric lesions, alopecia, polyarthritis, mucosal ulcerations, and progressive thrombocytopenia over a period of 10 months. During the work-up, the patient was evaluated for several viral infections. Serology testing showed elevation of anti-EBV, anti-CMV and anti-HSV1/2 IgM antibodies with the presence of IgG antibodies against all mentioned viruses except HSV2. Corticosteroid therapy was escalated, and azathioprine was introduced. Due to the persistence of significant thrombocytopenia and monoclonal IgG sternal puncture was performed. Morphological and immunohistochemical analysis of bone marrow specimen presented infiltration with metastatic deposits of adenocarcinoma and monoclonal plasmacytosis. Esophagogastroduodenoscopy showed multiple prepyloric erosions of gastric mucosa, which were biopsied. Pathohistological analysis demonstrated infiltration of gastric mucosa with diffuse type adenocarcinoma. Further PCR testing of biopsied gastric adenocarcinoma revealed the presence of EBV DNA in carcinoma tissue. The patient was sent to the oncologist for further evaluation. Conclusions: Assessment of SLE patients with persistently active disease should include the analysis of the herpesvirus infection status. Reactivations of EBV may be considered as possible trigger for lupus flares and the factor for increased risk of developing malignancies. © 2023 the author(s), published by De Gruyter, Berlin/Boston.

The hepatitis B surface antigen (HBsAg) is a multifunctional glycoprotein composed of large (LHB), middle (MHB), and small (SHB) subunits. HBsAg isoforms have numerous biological functions during HBV infection—from initial and specific viral attachment to the hepatocytes to initiating chronic infection with their immunomodulatory properties. The genetic variability of HBsAg isoforms may play a role in several HBV-related liver phases and clinical manifestations, from occult hepatitis and viral reactivation upon immunosuppression to fulminant hepatitis and hepatocellular carcinoma (HCC). Their immunogenic properties make them a major target for developing HBV vaccines, and in recent years they have been recognised as valuable targets for new therapeutic approaches. Initial research has already shown promising results in utilising HBsAg isoforms instead of quantitative HBsAg for correctly evaluating chronic infection phases and predicting functional cures. The ratio between surface components was shown to indicate specific outcomes of HBV and HDV infections. Thus, besides traditional HBsAg detection and quantitation, HBsAg isoform quantitation can become a useful non-invasive biomarker for assessing chronically infected patients. This review summarises the current knowledge of HBsAg isoforms, their potential usefulness and aspects deserving further research. © 2024 by the authors.

The hepatitis B surface antigen (HBsAg) is a multifunctional glycoprotein composed of large (LHB), middle (MHB), and small (SHB) subunits. HBsAg isoforms have numerous biological functions during HBV infection—from initial and specific viral attachment to the hepatocytes to initiating chronic infection with their immunomodulatory properties. The genetic variability of HBsAg isoforms may play a role in several HBV-related liver phases and clinical manifestations, from occult hepatitis and viral reactivation upon immunosuppression to fulminant hepatitis and hepatocellular carcinoma (HCC). Their immunogenic properties make them a major target for developing HBV vaccines, and in recent years they have been recognised as valuable targets for new therapeutic approaches. Initial research has already shown promising results in utilising HBsAg isoforms instead of quantitative HBsAg for correctly evaluating chronic infection phases and predicting functional cures. The ratio between surface components was shown to indicate specific outcomes of HBV and HDV infections. Thus, besides traditional HBsAg detection and quantitation, HBsAg isoform quantitation can become a useful non-invasive biomarker for assessing chronically infected patients. This review summarises the current knowledge of HBsAg isoforms, their potential usefulness and aspects deserving further research. © 2024 by the authors.

Despite the slow evolutionary rate of SARS‐CoV‐2 relative to other RNA viruses, its massive and rapid transmission during the COVID‐19 pandemic has enabled it to acquire signifi-cant genetic diversity since it first entered the human population. This led to the emergence of numerous variants, some of them recently being labeled “variants of concern” (VOC), due to their potential impact on transmission, morbidity/mortality, and the evasion of neutralization by antibodies elicited by infection, vaccination, or therapeutic application. The potential to evade neutralization is the result of diversity of the target epitopes generated by the accumulation of mutations in the spike protein. While three globally recognized VOCs (Alpha or B.1.1.7, Beta or B.1.351, and Gamma or P.1) remain sensitive to neutralization albeit at reduced levels by the sera of convalescent individuals and recipients of several anti‐COVID19 vaccines, the effect of spike variability is much more evident on the neutralization capacity of monoclonal antibodies. The newly recognized VOC Delta or lineage B.1.617.2, as well as locally accepted VOCs (Epsilon or B.1.427/29‐US and B1.1.7 with the E484K‐UK) are indicating the necessity of close monitoring of new variants on a global level. The VOCs characteristics, their mutational patterns, and the role mutations play in immune evasion are summarized in this review. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Despite the slow evolutionary rate of SARS‐CoV‐2 relative to other RNA viruses, its massive and rapid transmission during the COVID‐19 pandemic has enabled it to acquire signifi-cant genetic diversity since it first entered the human population. This led to the emergence of numerous variants, some of them recently being labeled “variants of concern” (VOC), due to their potential impact on transmission, morbidity/mortality, and the evasion of neutralization by antibodies elicited by infection, vaccination, or therapeutic application. The potential to evade neutralization is the result of diversity of the target epitopes generated by the accumulation of mutations in the spike protein. While three globally recognized VOCs (Alpha or B.1.1.7, Beta or B.1.351, and Gamma or P.1) remain sensitive to neutralization albeit at reduced levels by the sera of convalescent individuals and recipients of several anti‐COVID19 vaccines, the effect of spike variability is much more evident on the neutralization capacity of monoclonal antibodies. The newly recognized VOC Delta or lineage B.1.617.2, as well as locally accepted VOCs (Epsilon or B.1.427/29‐US and B1.1.7 with the E484K‐UK) are indicating the necessity of close monitoring of new variants on a global level. The VOCs characteristics, their mutational patterns, and the role mutations play in immune evasion are summarized in this review. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Hepatitis B virus (HBV) reactivation occurs as a major complication of immunosuppressive therapy among persons who have recovered from acute hepatitis and those who have controlled chronic infection. Recent literature data emphasize the presence of a high degree of S gene variability in HBV isolates from patients who developed reactivation. In reactivated HBV, the most frequently detected mutations belong to the second loop of “a” determinant in HBsAg. These mutations were identified to be immune escape and responsible for vaccine-and diagnostic-escape phenomena. Their emergence clearly provides survival in the presence of a developed humoral immune response and is often associated with impaired serological diagnosis of HBV reactivation. The knowledge of their existence and roles can elucidate the process of reactivation and strongly highlights the importance of HBV DNA detection in monitoring all patients with a history of HBV infection who are undergoing immunosuppression. This review discusses the possible influence of the most frequently found immune-escape mutations on HBV reactivation. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Hepatitis B virus (HBV) reactivation occurs as a major complication of immunosuppressive therapy among persons who have recovered from acute hepatitis and those who have controlled chronic infection. Recent literature data emphasize the presence of a high degree of S gene variability in HBV isolates from patients who developed reactivation. In reactivated HBV, the most frequently detected mutations belong to the second loop of “a” determinant in HBsAg. These mutations were identified to be immune escape and responsible for vaccine-and diagnostic-escape phenomena. Their emergence clearly provides survival in the presence of a developed humoral immune response and is often associated with impaired serological diagnosis of HBV reactivation. The knowledge of their existence and roles can elucidate the process of reactivation and strongly highlights the importance of HBV DNA detection in monitoring all patients with a history of HBV infection who are undergoing immunosuppression. This review discusses the possible influence of the most frequently found immune-escape mutations on HBV reactivation. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

Although the connection between Epstein–Barr virus (EBV) and rheumatoid arthritis (RA) has been studied for over 40 years, many questions still need clarification. The study aimed to analyze the possible association between anti-EBV antibody titers, EBV DNA viremia, EBV infection status and EBNA1 (Epstein–Barr nuclear antigen 1—EBNA1) variants and clinical parameters of RA patients. This prospective cohort study included 133 RA patients and 50 healthy controls. Active/recent EBV infection was more prevalent in RA patients than in controls (42% vs. 16%, p < 0.001). RA patients had higher titers of anti-EBV-CA-IgM (capsid antigen—CA) and anti-EBV-EA(D)-IgG (early antigen—EA) antibodies than controls (p = 0.003 and p = 0.023, respectively). Lower levels of anti-EBNA1-IgG and anti-EBV-CA-IgG were observed in RA patients who received methotrexate (anti-EBNA1 IgG p < 0.001; anti-EBV-CA IgG p < 0.001). Based on amino acid residue on position 487, two EBNA1 prototypes were detected: P-Thr and P-Ala. Patients with active/recent EBV infection had a five times more chance of having RA and a nearly six times more chance of getting RA. Also, EBV active/recent infection is twice more likely in newly diagnosed than in methotrexate-treated patients. Further studies are needed to clarify “who is the chicken and who is the egg” in this EBV–RA relationship. © 2023 by the authors.