Surface Antibody Research Articles

Changes in the Rate of Leucine-Rich Glioma-Inactivated 1 Seropositivity During the COVID-19 Lockdown

This case-control study investigates the positivity rates of the most prevalent neuroglial surface antibodies during the COVID-19 pandemic.

Effect of Anti-HBs on Mortality Among Resolved HBV Infection: a Population-Based Prospective Cohort Study.

Surveillance programs after hepatitisB surface antigen (HBsAg) loss are not yet well established, and the role of hepatitisB surface antibodies (anti-HBs) remains controversial. We aimed to evaluate the risk factors for increased mortality and the association between anti-HBs and all-cause and cause-specific mortality in a representative US (United States) population of patients with resolved HBV (Hepatitis B virus) infections. Data were taken from the US National Health and Nutrition Examination Survey (NHANES) 1999-2018. A total of 3455 US adults with resolved HBV infection [defined as hepatitisB surface antigen (HBsAg) negative/anti-hepatitisB core antigen (anti-HBc) positive] were enrolled in this study. The primary outcome measures were all-cause and cause-specific mortality from baseline until 31December 2019. During a mean follow-up of 10.3years, 741 deaths occurred. Age, race, marital status, smoking status, physical activity level, and presence of cirrhosis, diabetes, cardiovascular diseases, chronic obstructive pulmonary diseases, cancer, and anti-HBs were significant factors forincreased mortality, and a nomogram tool was developed and validated for the risk stratification of mortality. Compared with participants who were anti-HBs positive, those who were anti-HBs negative had a 23% (hazard ratio 1.23, 95%CI 1.02-1.46) higher risk of all-cause mortality in NHANES 1999-2018. For cause-specific mortality, the fully adjusted hazard ratios of participants who were anti-HBs negative were 0.71 (95%CI 0.48-1.06) for heart disease, 1.44 (95%CI 1.01-2.05) for cancer, and 1.44 (95%CI 1.13-1.83) for other conditions, compared to those of participants who were anti-HBs positive. Among US adults with resolved HBV infections, anti-HBs-negative status was associated with an increased risk of death from all causes and cancer, implying that the role of anti-HBs in resolved HBV infection should not be ignored. On the public health level, more rigorous surveillance was needed for populations of individuals who were isolated anti-HBc positive.

Changing incidence of hepatitis B and persistent infection risk in adults: a population-based follow-up study from 2011 in China

BackgroundThis study aimed to estimate hepatitis B incidence and chronicity risk in rural adults in China under the background of eliminating viral hepatitis.MethodsHepatitis B surface antigen (HBsAg) screening was conducted every 2 years in demonstration areas since 2011. Individuals with baseline HBsAg-negative were included. Incidence was calculated as the number of HBsAg-positive cases divided by the total person-times. HBsAg-positive individuals were followed up to study the persistent infection (> 6 months), chronic infection (> 12 months), and recovery with hepatitis B surface antibody (anti-HBs). The chi-square test and cox proportional regression analysis were performed.ResultsThere were 8,942 incident cases over 2,138,532 person-years, yielding an average incidence of 0.42 per 100 person-years. HBV incidence decreased rapidly in both genders and all age groups and then kept stable. Male gender, low population density, low gross domestic product per capita, and islanders were associated with higher incidence. Of the positive cases, 4,989 (55.8%) patients were followed up. The persistent infection, chronic infection, and recovery with anti-HBs rates were 32.3%, 31.0%, and 31.4%, respectively. Persistent or chronic infection was more common in younger adults and males, while seroconversion had no concern with gender or age.ConclusionsHBV incidence in adult rural residents was decreasing and stayed low. The chronicity rate was relatively high and protective antibodies were induced in only one third. The importance of population-based screening and vaccination for susceptible individuals should be addressed.

Epidemiology of Chronic Hepatitis B Infection in the Cohort of College Students with Vaccination in Taiwan.

After the mass vaccination project in Taiwan, the prevalence of the hepatitis B virus (HBV) infection for the college-aged population of 18 to 21 years is uncertain. We aimed to investigate the prevalence of hepatitis B markers in different birth cohorts. A total of 38,075 students in universities in Kaohsiung area undergoing entrance examinations between July 2006 to September 2020 were included. Seroprevalence of the hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (anti-HBs) status and laboratory data were collected. The seropositive rate of HBsAg was less than 1% for students born after 1991. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were significantly higher, and body mass index (BMI) was significantly lower in HBV carriers compared to those who were not carriers (all p < 0.001). Multivariate logistic regression showed that age, male, higher BMI, and positive HBsAg were risk factors of abnormal ALT value. A decrease in the positive rate of anti-HBs which was significantly higher in the cohort of plasma-derived vaccines than recombinant vaccines was found. We concluded that there were decreasing trends in seropositive rates of HBsAg and anti-HBs for students of the college-aged population in the Kaohsiung area. The status of HBsAg was a predictive factor of abnormal ALT levels. The period effect on anti-HBs seropositivity for DNA recombinant vaccine somehow existed.

Vesicular Antibodies: Shedding Light on Antibody Therapeutics with Cell Membrane Nanotechnology.

The high stability of antibodies and their ability to precisely bind to antigens and endogenous immune receptors, as well as their susceptibility to protein engineering, enable antibody-based therapeutics to be widely applied in cancer, inflammation, infection, and other disorders. Nevertheless, the application of traditional antibody-based therapeutics has certain limitations, such as high price, limited permeability, and protein engineering complexity. Recent breakthroughs in cell membrane nanotechnology have deepened the understanding of the critical role of membrane protein receptors in disease treatment, enabling vesicular-antibody-based therapeutics. Here, the concept of vesicular antibodies that are obtained by modifying target antibodies onto cell membranes for biomedical applications is proposed. Given that an antibody is basically a protein, as an extension of this concept, vesicles or membrane-coated nanoparticles that use surface antibodies and protein receptors on cell membranes for biomedical applications as vesicular antibodies are defined. Furthermore, several engineering strategies for vesicular antibodies are summarized and how vesicular antibodies can be used in a variety of situations is highlighted. In addition, current challenges and future prospects of vesicular antibodies are also discussed. It is anticipated this perspective will provide new insights on the development of next-generation antibodies for enhanced therapeutics.

Occult hepatitis B in patients with cancer during immunotherapy with or without chemotherapy: A real-life retrospective single-center cohort study.

Few data about the safety of immune checkpoint inhibitors (ICIs) in the patients with solid tumor with Occult Hepatitis B Virus (OBI) are available. According to the Taormina Workshop on Occult HBV Infection Faculty Members we defined as potential-OBI (pOBI) the HBV DNA negativity with anti-hepatitis B core antibody (anti-HBc) positivity (pOBI seropositive), and the patients with HBsAg-negative and anti-HBc-negative and Hepatitis B surface antibody (anti-HBs)-negative are defined pOBI seronegative. The aim of this study is to investigate the prevalence of OBI in patients with solid tumors undergoing ICIs with or without chemotherapy and the incidence of reactivation (HBVr). We retrospectively enrolled all HBsAg negative subjects who had received ICIs for at least three months. HBsAg and HBV DNA levels were repeated every 3 months until the end of the study and/or in case of ALT alterations. A univariate analysis was conducted in order to study for each variable available its ability to distinguish a potential OBI seropositive patient from a seronegative one. 150 patients in our Oncology Unit were eligible. One hundred and seventeen patients (78%) received ICI as monotherapy, whereas 33 patients (22%) were treated with chemo-immunotherapy. The mainly used drugs for the ICI monotherapy were Pembrolizumab (47%), Nivolumab (33%) and Atezolizumab (11%). The prevalence of pOBI seropositive patients was 25.3%. We did not observe alterations of liver biochemistry nor HBVr. This study highlights that about a quarter of our population had a potential occult hepatitis B. Immunotherapy might be considered as low risk of reactivation, regardless of the potential presence of episomal covalently closed circular DNA (cccDNA) in the liver, but the correct management still represents a challenge for oncologists and hepatologists.

Seroconversion following Heplisav-B, hepatitis B vaccine (recombinant), adjuvanted, in patients with end-stage renal disease at an urban safety net hospital.

Heplisav-B is a novel recombinant adjuvanted vaccine for hepatitis B virus (HBV) that has been approved as a 2-dose regimen and shown to have similar seroconversion rates in healthy adults as single-antigen HBV vaccines. More data are needed to determine whether similarly high rates of seroconversion and immunity are observed in immunocompromised patient populations such as in patients with end-stage renal disease (ESRD) on hemodialysis. Patients with ESRD who presented for emergency-only hemodialysis and either were HBV vaccine naive or had a hepatitis B surface antibody (anti-HBs) titer of less than 10 IU/mL received 3 standard 20-μg doses of Heplisav-B at week 0, week 4 (±2 weeks), and week 24 (±2 weeks), with anti-HBs titer measured at week 28 (±2 weeks). Thirty-two patients received at least one dose in the study timeframe, with 24 patients completing the vaccine series and measurement of anti-HBs titer. The mean age of the patients was 46 years, and 58% of patients were male. Of the 24 patients who completed the vaccine series, 20 (83%) seroconverted after the third dose. Three of the 4 patients who did not seroconvert after 3 doses were revaccinated with an additional 20-μg dose, and 2 of the 3 patients had an anti-HBs titer of greater than 10 IU/mL 4 weeks after this dose. Patients with ESRD who received three 20-μg doses of recombinant HBV vaccine had a seroconversion rate of 83%, representing a similar seroconversion rate and fewer doses of vaccine as compared to the standard HBV vaccine regimen for patients with ESRD.

Neuronal surface antigen-specific immunostaining pattern on a rat brain immunohistochemistry in autoimmune encephalitis.

A variety of neuronal surface (NS) antibodies (NS-Ab) have been identified in autoimmune encephalitis (AE). Tissue-based assay (TBA) using a rodent brain immunohistochemistry (IHC) is used to screen NS-Ab, while cell-based assay (CBA) to determine NS antigens. Commercial rat brain IHC is currently available but its clinical relevance remains unclear. Immunostaining patterns of NS antigens have not been extensively studied yet. To address these issues, we assessed a predictive value of "neuropil pattern" and "GFAP pattern" on commercial IHC in 261 patients, and characterized an immunostaining pattern of 7 NS antigens (NMDAR, LGI1, GABAaR, GABAbR, AMPAR, Caspr2, GluK2). Sensitivity and specificity of "neuropil pattern" for predicting NS-Ab were 66.0% (95% CI 55.7-75.3), and 98.2% (95% CI 94.8-99.6), respectively. False-positive rate was 1.8% (3/164) while false-negative rate was 34.0% (33/97). In all 3 false-positive patients, neuropil-like staining was attributed to high titers of GAD65-Ab. In 33 false-negative patients, NMDAR was most frequently identified (n=18 [54.5%], 16/18 [88.9%] had low titers [< 1:32]), followed by GABAaR (n=5). Of 261 patients, 25 (9.6%) had either GFAP (n=21) or GFAP-mimicking pattern (n=4). GFAP-Ab were identified in 21 of 31 patients examined with CBA (20 with GFAP pattern, 1 with GFAP-mimicking pattern). Immunostaining pattern of each NS antigen was as follows: 1) NMDAR revealed homogenous reactivity in the dentate gyrus molecular layer (DG-ML) with less intense dot-like reactivity in the cerebellar granular layer (CB-GL); 2) both GABAaR and GluK2 revealed intense dot-like reactivity in the CB-GL, but GABAaR revealed homogenous reactivity in the DG-ML while GluK2 revealed intense reactivity along the inner layer of the DG-ML; and 3) LGI1, Caspr2, GABAbR, and AMPAR revealed intense reactivity in the cerebellar ML (CB-ML) but LGI1 revealed intense reactivity along the middle layer of the DG-ML. Whereas, Caspr2, GABAbR, and AMPAR revealed similar reactivity in the DG-ML but some difference in other regions. TBA is useful not only for screening NS- or GFAP-Ab but also for estimating NS antigens; however, negative results should be interpreted cautiously because "neuropil pattern" may be missed on commercial IHC when antibody titers are low. Antigen-specific immunoreactivity is a useful biomarker of AE.

Spontaneous regression of immunoglobulin G4-related dacryoadenitis and multiple organ involvement: A case report

Immunoglobulin G4 (IgG4)-related dacryoadenitis is rarely resolved spontaneously without steroids. Here, we report a case of IgG4-related dacryoadenitis and extra-ophthalmic lesions with spontaneous regression. This is a clinical case report. A 56-years-old man had a 1-year and 7-month-old histories of neck and eyelid swelling, respectively. On the first examination, the lacrimal and submandibular glands were palpable bilaterally. Computed tomographic images showed enlargement of the lacrimal gland on both sides, right pulmonary hilar lymph node, and pancreas, and thickening of the abdominal aortic wall. Blood tests demonstrated elevated serum IgG4 level and positive hepatitis B surface antibody. Pathological examination of the biopsied lacrimal gland specimens revealed marked IgG4-positive plasma cell infiltration. The patient was monitored carefully without steroid administration. Serum IgG4 level had gradually decreased during follow-up period and reached the normal range 3 years after the biopsy. At 4-year follow-up, the lacrimal and submandibular glands were not palpable on either side. Computed tomographic images demonstrated no enlargement of the lacrimal gland, submandibular gland, or lymph nodes, and improvement of the enlarged pancreas and thickened abdominal aortic wall. Our case indicates that careful observation can be an option in selected cases with risks of steroid treatment or silent clinical course.

Immune Status for Hepatitis B and Risk for Occupational Exposure Virus Among Italian Nurses

Background: Healthcare workers (HCWs) are considered at higher risk for hepatitis B virus infection compared to the general population, due to their potential contact with blood or body fluids and possible needle stick injuries. In turn, infected HCWs may be a risk for patients. Hepatitis B vaccination programs represent a strategic approach to control the infection. Objectives: In this study, we aimed to evaluate the serological status of HCWs employed at the teaching hospital of Rome Tor Vergata and their risk of occupational injuries after the adoption of directive 2010/32/EU. Methods: Medical records of 539 HCWs were evaluated during their occupational medical examination at the Tor Vergata teaching hospital (PTV). All subjects were screened for specific viral markers: Hepatitis B surface antibodies (anti-HBs IgG), antibodies to hepatitis core antigen (anti-HBc IgG), and hepatitis B surface antigen (HBsAg). Data regarding needlestick injuries were collected by the prevention service team during the same year. Results: In this sample population, we found five subjects (0.9%) positive to the HBsAg, and most of them (four) were born in foreign countries. Moreover, seven subjects (1.3% of our population) were HBsAg-positive and anti-HBc-positive. A protective anti-HBs titer was found in 462 out of 527 (85.7%) subjects. The risk of being serologically unprotected was higher in males and subjects aged 40 years or older. The nurses were more protected than other healthcare professionals considering the anti-hepatitis B surface antibody titer. In 2018, 16 needlestick injuries were reported among our population of HCWs, with a global risk of 2.9% per year. Conclusions: Although hepatitis B virus (HBV) infection rate among HCWs was similar to that of the general population, the risk of HBV transmission in HCWs was likely to be high due to suboptimal vaccination coverage.

Immune Status for Hepatitis B and Risk for Occupational Exposure Virus Among Italian Nurses

Background: Healthcare workers (HCWs) are considered at higher risk for hepatitis B virus infection compared to the general population, due to their potential contact with blood or body fluids and possible needle stick injuries. In turn, infected HCWs may be a risk for patients. Hepatitis B vaccination programs represent a strategic approach to control the infection. Objectives: In this study, we aimed to evaluate the serological status of HCWs employed at the teaching hospital of Rome Tor Vergata and their risk of occupational injuries after the adoption of directive 2010/32/EU. Methods: Medical records of 539 HCWs were evaluated during their occupational medical examination at the Tor Vergata teaching hospital (PTV). All subjects were screened for specific viral markers: Hepatitis B surface antibodies (anti-HBs IgG), antibodies to hepatitis core antigen (anti-HBc IgG), and hepatitis B surface antigen (HBsAg). Data regarding needlestick injuries were collected by the prevention service team during the same year. Results: In this sample population, we found five subjects (0.9%) positive to the HBsAg, and most of them (four) were born in foreign countries. Moreover, seven subjects (1.3% of our population) were HBsAg-positive and anti-HBc-positive. A protective anti-HBs titer was found in 462 out of 527 (85.7%) subjects. The risk of being serologically unprotected was higher in males and subjects aged 40 years or older. The nurses were more protected than other healthcare professionals considering the anti-hepatitis B surface antibody titer. In 2018, 16 needlestick injuries were reported among our population of HCWs, with a global risk of 2.9% per year. Conclusions: Although hepatitis B virus (HBV) infection rate among HCWs was similar to that of the general population, the risk of HBV transmission in HCWs was likely to be high due to suboptimal vaccination coverage.

Underlying diseases, nutritional assessment, viral incidence and HBV immunity status in patients undergoing hemodialysis

Introduction: Underlying kidney diseases and their progression cease the function of kidney and raise the need for regular maintenance dialysis. Furthermore, nutritional requirements and blood born viral infections affect their quality of life. Objectives: This study aims to investigate viral incidence, underlying kidney diseases, nutritional status; and hepatitis B virus (HBV) immunity status in hemodialysis (HD) patients. Patients and Methods: A total of 330 end-stage renal disease (ESRD) patients were assessed for human immunodeficiency virus (HIV), HBV, hepatitis C virus (HCV) viruses using Enzyme-linked immunosorbent assay (ELISA) assay. The underlying kidney diseases were confirmed by a physician. Eighty-two subjects with diabetic nephropathy are referred to dietitian for nutritional assessments and body mass index (BMI) measurement. Hepatitis B surface antibody (Anti-HBs) tests were done at two different times of year for 94 qualified subjects. Results: Out of 330 patients 82 (24.8%) had diabetic mellitus (DM), 5 (1.5%) myocardial infarction (MI), 3 (0.9%) systemic lupus erythematosus (SLE), 55 (16.7%) hypertensive nephrosclerosis (HN), 3 (0.9%) obstructive nephropathy, 5 (1.5%) autosomal dominant polycystic kidney disease (ADPKD), and 4 (1.2%) glomerulonephritis. 45 cases (13.6%) had DM and HTN simultaneously. Eleven percent of diabetic nephropathy (DN) patients had severe malnutrition. Only five men (1.51%) were positive for HBV. No incidence of HCV and HIV was seen. Findings showed a dramatic change for anti-HBs after 6 months. Conclusion: Despite the advances in medicine, malnutrition and viral diseases still threaten dialysis patients. DM was the most common underlying disease. The safety of dialysis patients for HBV is compromised after regular dialysis, underscoring the importance of strict adherence to vaccination program.

Protective Antibody Titer against Hepatitis B in Healthcare Workers: A Cross-sectional Study from Tertiary Care Hospital of Kashmir

Introduction: Hepatitis B is not only the most transmissible blood borne viral infection, but also the only one that is preventable by vaccination. In developing countries, Hepatitis B vaccination coverage among Healthcare Workers (HCWs) is very low for various reasons. Aim: To evaluate Hepatitis B Virus (HBV) immunisation status and Hepatitis B surface antibody (anti-HBs) titer among HCWs in a tertiary care hospital in Kashmir. Materials and Methods: This cross-sectional study was conducted in the Department of Microbiology, Government Medical College, Srinagar, India from April 2019 to June 2019. Serum samples were collected from 196 HCWs and their vaccination history was collected. Those who had taken all three doses of hepatitis B were considered to be fully vaccinated those that had taken two doses as partially vaccinated. Triple serology was done for all which included testing for HBV, Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) infection, one HCW turned out to be Hepatitis B Surface Antigen (HBsAg) positive and was dropped out of study. Those negative (195/196) were further tested for anti-HBs titer by enzyme immunoassay method. Parametric data are expressed as mean±Standard Deviation (SD) and categorical values as percentages. Results: Out of 195 HCWs selected for the study, 112 (57.4%) were males and 84 (43%) were females with mean age 38.4±6.9 years. Among them fully vaccinated were 46 (23.5%), partially vaccinated were 84 (43.07%) and not vaccinated were 65 (33.33%). Anti-HBs titers were protective in 54 (27.7%) which belonged 81.5% (44/54) to vaccinated category and 18.5% (10/54) to partially vaccinated category. Conclusion: Fully vaccinated HCWs (95.6%) had a protective antibody titer but unfortunately there are low vaccination rates among HCWs. There is a need for well-planned and clear policies for HBV screening and vaccination in HCWs, especially those who are at a greater risk of exposure to blood or other potentially infectious material.

Serologic status and vaccine response against hepatitis B virus after allogeneic hematopoietic cell transplantation in pediatric patients.

Although vaccination against hepatitis B virus (HBV) is recommended for hematopoietic cell transplantation (HCT) recipients, previous studies evaluating serologic status and immunologic response to HBV vaccination in pediatric allogeneic HCT recipients are not enough. This study aimed to evaluate serologic status against HBV and immunologic responses to HBV vaccination in children and adolescents receiving allogeneic HCTs. Medical records of the enrolled 61 pediatric patients < 19 years of age who received their first allogeneic HCTs were retrospectively reviewed. Twenty-two (36.1%) of the enrolled patients were positive for hepatitis B surface antibody (HBsAb) after HCT. Chronic graft-versus-host disease was significantly associated with negative HBsAb status after HCT (p = 0.01). With one dose of HBV vaccination after HCT, 40.5% of the vaccinated patients became positive for HBsAb. No clinical factor was associated with the positive conversion of HBsAb after vaccination. Considering the unsatisfactory seropositive rate and vaccine response against HBV and the lack of significant clinical and laboratory factors predicting serostatus in HCT recipients, universal three doses of HBV vaccination should be necessary after allogeneic HCT.

Hepatitis B antibody levels after different doses of hepatitis B vaccination: a retrospective study based on hospitalized children.

Many studies have investigated the positivity rate of hepatitis B surface antibody (HBsAb) after hepatitis B vaccine (HepB) immunization. However, the antibody level, assessed monthly or at more frequent intervals after each of the three doses, particularly within the first year after birth, has not been previously reported. To elucidate the level of antibody formation at various times after vaccination, the current study used the available detection data of HBsAb in hospitalized children to analyze the HBsAb level after immunization combined with their vaccination history. Both the positivity rate and geometric mean concentration (GMC) increased sequentially with immunization doses, reaching their peaks earlier after the third dose than after the first two doses, and the rate of HBsAb positivity was able to reach 100% between 11 and 90days after completing the three doses of HepB. Within one year after receiving the three doses, the antibody positivity rate and GMC were maintained above 90% and 100 mIU/mL, respectively, and subsequently steadily declined, reaching the lowest value in the 9th and 10th years. The current findings reveal, in more detail, the level of antibody formation at different times following each dose of HepB in hospitalized children, particularly in the age group up to one year after vaccination. For the subjects of this study, we prefer to believe that the proportion of HBsAb non-response should be less than 5% after full immunization with HepB, provided that the appropriate time for blood collection is chosen.

Cell surface glycoproteomics: deciphering glycoproteins through a unique analytical capture approach.

Cell surface proteins (CSPs) are often involved in various biological processes such as cell-cell interactions, immune responses, and molecular transport. The abnormal expression of CSP usually indicates the occurrence and development of human diseases. Most CSPs are glycosylated and have been explored as potential drug targets and disease biomarkers; however, efficient isolation of CSPs from intracellular proteins is difficult due to their low abundance and strong hydrophobicity. The comprehensive characterization of surface glycoproteins remains a great challenge and is often underrepresented in proteomics. In recent years, unprecedented progress has been made in the mass spectrometry analysis of surface proteins, and CSP capture methods and mass spectrometry have been greatly developed. In this article, we aim to give a comprehensive overview of innovative analytical methods that can enrich CSPs, including centrifugation-based separation, phase partitioning, adhesion-based capture of surface proteins, antibody or lectin affinity, and biotin-based chemical labeling. Surface glycoproteins are captured by chemical oxidation of glycans or click chemistry for carbohydrate metabolic labeling. These techniques offer a wide range of applications for studying the function of cell surface receptors and identifying markers for diagnostic and therapeutic development.

Prevalence of hepatitis B virus infection among pregnant women in the mountainous regions of southern China: A retrospective single‐center study

Hepatitis B virus (HBV) infection remains a major public health issue worldwide. Moreover, its prevalence varies significantly in different geographic areas of China. The current study aimed to assess the prevalence of HBV infection among Hakka pregnant women in Meizhou, a remote mountainous region in southern China. This research was performed between January 2015 and December 2020. In total, 16,727 pregnant women receiving antenatal care at Meizhou People's Hospital were included in the analysis. All pregnant women were screened for serum HBV markers. The prevalence rates of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody positivity among the participants were 11.74% (n=1964) and 48.00% (n=8029), respectively. The overall prevalence rates of susceptibility to infection, HBV immunity, previous/occult infection, inactive HBsAg carrier, and active infection were 36.16%, 33.61%, 16.94%, 8.11%, and 2.30%, respectively. According to age distribution, the prevalence rate of HBsAg positivity elevated concomitantly with increasing age (p < 0.001). From 2015 to 2020, the prevalence rate of HBsAg positivity decreased from 14.50% to 8.19% and that of hepatitis B pre-core antigen positivity from 4.42% to 2.31%. In addition, pregnant women with HBsAg-positive status were more likely to present with gestational diabetes, thrombocytopenia, and anemia than those with HBsAg-negative status. The HBV infection rate remains high among pregnant women in the indigenous Hakka population in southern China. To prevent vertical transmission, cautious surveillance of maternal HBV infection status should be considered in Hakka pregnant women in Meizhou.

Role of lower dose hepatitis B immune globulin prophylaxis in liver transplantation: A single center perspective.

Prevention of hepatitis B virus (HBV) reinfection is important for long-term outcomes following liver transplantation (LT). Hepatitis B immunoglobulin (HBIG) is used among recipients who have (i) native HBV disease, (ii) hepatitis B core antibody positivity (HBcAb positivity), or (iii) received HBcAb positive organs. Nucleos(t)ide analogue (NA) monotherapy is emerging for treating patients in this setting. There is no generalized consensus on the ideal dosage of HBIG. The aim of this study was to evaluate the efficacy of low-dose HBIG (1560 international unit [IU]) for post-LT HBV prevention. HBcAb positive patients who received either HBcAb positive or hepatitis B core antibody negative (HBcAb negative) organs and HBcAb negative patients who received HBcAb positive organs between January 2016 and December 2020 were reviewed. Pre-LT HBV serologies were collected. HBV-prophylaxis strategy included NA with/without HBIG. HBV recurrence was defined as HBV deoxyribonucleic acid (DNA) positivity during the 1-year, post-LT follow-up. No HBV surface antibody titers were followed. A total of 103 patients with a median age of 60 years participated in the study. Hepatitis C virus was the most common etiology. Thirty-seven HBcAb negative recipients and 11 HBcAb positive recipients with undetectable HBV DNA received HBcAb positive organs and underwent prophylaxis with 4 doses of low-dose HBIG and NA. None of the recipients in our cohort had a recurrence of HBV at 1 year. Low-dose HBIG (1560 IU) × 4 days and NA, for HBcAb positive recipients and HBcAb positive donors, appear to be effective in preventing HBV reinfection during the post-LT period. Further trials are needed to confirm this observation.

EGF‑IL2 bispecific and bivalent EGF fusion toxin efficacy against syngeneic head and neck cancer mouse models.

The epidermal growth factor receptor (EGFR) remains one of the best molecules for developing targeted therapy for multiple human malignancies, including head and neck squamous cell carcinoma (HNSCC). Small molecule inhibitors or antibodies targeting EGFR have been extensively developed in recent decades. Immunotoxin (IT)‑based therapy, which combines cell surface binding ligands or antibodies with a peptide toxin, represents another cancer treatment option. A total of 3 diphtheria toxin (DT)‑based fusion toxins that target human EGFR‑monovalent EGFR IT (mono‑EGF‑IT), bivalent EGFR IT (bi‑EGF‑IT), and a bispecific IT targeting both EGFR and interleukin‑2 receptor (bis‑EGF/IL2‑IT) were recently generated by the authors. Improved efficacy and reduced toxicity of bi‑EGF‑IT compared with mono‑EGF‑IT in immunocompromised HNSCC mouse models was reported. In the present study, bis‑EGF/IL2‑IT were generated using a unique DT‑resistant yeast expression system and evaluated the invitro and invivo efficacy and toxicity of the 3 EGF‑ITs in immunocompetent mice. The results demonstrated that while the three EGF‑ITs had different efficacies invitro and invivo against HNSCC, bi‑EGF‑IT and bis‑EGF/IL2‑IT had significantly improved invivo efficacy and remarkably less off‑target toxicity compared with mono‑EGF‑IT. In addition, bis‑EGF/IL2‑IT was superior to bi‑EGF‑IT in reducing tumor size and prolonging survival in the metastatic model. These data suggested that targeting either the tumor immune microenvironment or enhancing the binding affinity could improve the efficacy of IT‑based therapy. Bi‑EGF‑IT and bis‑EGF/IL2‑IT represent improved candidates for IT‑based therapy for future clinical development.

639. Vaccination in Kidney Transplant Candidates

Abstract Background Kidney transplant (KT) candidates have historically low immunization rates against recommended vaccines. A retrospective study of KT candidates was conducted to assess contemporary vaccination rates and vaccine uptake during pre-transplant evaluation. Methods All KT candidates ≥ 18 years referred to Transplant Infectious Disease Clinic for pre-transplant evaluation between January 1, 2020 and August 31, 2020 were retrospectively studied for history of prior vaccination against Tdap, 13 valent pneumococcal conjugate vaccine (PCV13), 23 valent pneumococcal polysaccharide vaccine (PPSV23), Hepatitis A and B (using Hepatitis A total IgG and Hepatitis B surface antibodies as surrogate markers) and recombinant zoster vaccine (RZV). Seropositivity (as a marker of immunity) against measles, mumps, rubella and varicella was also assessed. Results 109 KT candidates were evaluated (tables 1 &amp; 2). Rates of prior vaccination against Tdap, PCV13 and PPSV23 were 33%, 58%, and 67%. Only 5 (8%) of 61 patients ≥ 50 years of age had received 2 doses of RZV. Thirty (28%) had positive Hepatitis A total IgG and 72 (66%) patients had a positive Hepatitis B surface antibody. Among 37 patients with negative Hepatitis B surface antibody, most had received at least one dose of Hepatitis B vaccine (five were non responders, 19 had had initiated the vaccine series and one had waning antibody response). 79-96% patients had immunity against measles, mumps, rubella and varicella. Patients ≥ 50 years (vs under 50 years) had numerically higher immunization rates against PCV13 and PPSV23 (67% vs 46% and 74% vs 58%) and higher rates of immunity against measles, mumps, rubella and varicella (95% vs 73%; 85% vs 69%, 95% vs 81% and 100% vs 92% respectively). Dialysis patients had a higher Hepatitis B surface antibody compared to non-dialysis patients (78% vs 39%). Only 6 of 109 patients were fully immunized. Among 103 vaccine eligible patients, 99 (96%) agreed to get vaccinated. Table 1Baseline characteristics of kidney transplant candidates Table 2 Vaccination in kidney transplant candidates Conclusion KT candidates have low rates of prior immunization against Tdap, PCV13, PPSV23, Hepatitis A and B and RZV but high rates of serological immunity against measles, mumps, rubella and varicella. The vaccine uptake during pre-transplant evaluation was high and it provides an unique opportunity to improve immunization in this population. Disclosures All Authors: No reported disclosures.