Changes In Antibody Titers Research Articles

Analyses of the association between Helicobacter pylori antibody titre and pathogenicity before and after eradication: results of the Kyushu and Okinawa population study, a retrospective observational cohort study

ObjectivesTo assess the utility of Helicobacter pylori antibody testing, we evaluated the correlation between the H. pylori antibody titre and H. pylori-associated pathogenicity and the changes in antibody titre after...

Antibody levels against respiratory syncytial virus fusion protein conformations and lack of association with life-threatening infection in previously healthy infants

BackgroundHumoral immune response against the pre-fusion (pre-F) conformation of respiratory syncytial virus (RSV) F protein has been proposed to play a protective role against infection. An RSV pre-F maternal vaccine has been recently approved in several countries to protect young infants against RSV. We aimed to assess serum IgG titers against the pre-F and post-F conformations of RSV F protein and their association with life-threatening RSV disease (LTD) in previously healthy infants. MethodsA prospective cohort study including hospitalized infants <12 months with a first RSV infection was conducted during 2017–2019. Patients with LTD required intensive care and mechanical respiratory assistance. RSV pre-F exclusive and post-F antibody responses were determined by post-F competition and non-competition immunoassays, respectively, and neutralizing activity was measured by plaque reduction neutralization test. ResultsFifty-eight patients were included; the median age was 3.5 months and 41 % were females. Fifteen patients developed LTD. RSV F-specific antibody titers positively correlated with neutralizing antibody titers in acute and convalescent phases but, importantly, they did not associate with LTD. Acute RSV pre-F exclusive and post-F IgG titers negatively correlated with patient age (P = 0.0007 and P < 0.0001), while a positive correlation was observed between the fold changes in RSV F-specific antibody titers between convalescent and acute phase and patient age (P = 0.0014 and P < 0.0001). Infants ≤2 months exhibited significantly lower fold-changes in RSV F-specific and neutralizing antibody titers between convalescence and acute phase than older infants. Additionally, acute RSV antibody titers showed no correlation with nasal RSV load and, furthermore, nasal viral load was not associated with the development of LTD. ConclusionsThis study highlights that protection against life-threatening RSV disease is not necessarily antibody-dependent. Further characterization of the immune response against RSV and its role in protection against severe disease is important for the development of the safest possible preventive strategies.

A significant outbreak of respiratory human adenovirus infections among children aged 3-6 years in Hokkaido, Japan, in 2023.

Human adenovirus (HAdV) infections present diverse clinical manifestations upon infecting individuals, with respiratory infections predominating in children. We surveyed pediatric hospitalizations due to respiratory HAdV infections across 18 hospitals in Hokkaido Prefecture, Japan, from July 2019 to March 2024, recording 473 admissions. While hospitalizations remained below five cases per week from July 2019 to September 2023, a notable surge occurred in late October 2023, with weekly admissions peaking at 15-20 cases from November to December. There were dramatic shifts in the age distribution of hospitalized patients: during 2019-2021, 1-year-old infants and children aged 3-6 years represented 51.4%-54.8% and 4.1%-13.3%, respectively; however, in 2023-2024, while 1-year-old infants represented 19.0%-20.1%, the proportion of children aged 3-6 years increased to 46.2%-50.0%. Understanding the emergence of significant outbreaks of respiratory HAdV infections and the substantial changes in the age distribution of hospitalized cases necessitates further investigation into the circulating types of HAdV in Hokkaido Prefecture and changes in children's neutralizing antibody titers against HAdV.

Positive Outcome in a Pregnancy with Anti-kell Alloimmunization Treated with Intravenous Immunglobulin and Therapeutic Plasma Exchange Despite Persistence of High Titre Antibody: A Case Report

Background: Few reports have been published about the current clinical management of anti-Kell alloimmunization in pregnancy; its low frequency of occurrence means that the few long series published have covered an extensive time period in which different treatment approaches have overlapped. The objective of the present paper is to present our experience in the clinical management of a pregnant woman who was positive for the anti-Kell antibody. Materials and Methods: The laboratory follow-up included the weekly measurement of the antibody titre, and identification of the paternal and fetal genotype. The clinical management included TPE and IVIG administration. Obstetric monitoring included ultrasonographic monitoring of the fetus. Case Description: We report a case of anti-Kell alloimmunization with high antibody titre at first observation. Testing for fetal DNA circulating in maternal blood confirmed positivity for KEL1 gene. The patient underwent fifteen sessions of TPE after 18 weeks of gestational age, followed by weekly IVIG infusion, which continued until 27 weeks of pregnancy. Anti-Kell titres were measured before and after each TPE session. The patient had no need for IUBT and delivered by cesarean section at 34 weeks of gestational age. Pregnancy resulted in a live birth with mild HDFN. Discussion: HDFN is a potentially lethal complication of alloimmunization, and IUBT is the standard treatment for severe fetal anemia. TPE and IVIG are two alternative treatment modalities described in the literature to avoid or postpone the need for IUBT transfusion. In the case reported, despite any substantial change in antibody titre, pregnancy resulted in a live birth. This result suggests that the use of TPE and IVIG in alloimmunization during pregnancy could be an effective treatment strategy.

Target engagement and immunogenicity of an active immunotherapeutic targeting pathological α-synuclein: a phase 1 placebo-controlled trial

Investigational therapeutics that target toxic species of α-synuclein (αSyn) aim to slow down or halt disease progression in patients with Parkinson’s disease (PD). Here this 44-week, randomized, placebo-controlled, double-blind, single-center phase 1 study investigated safety, tolerability and immunogenicity of UB-312, an active immunotherapeutic targeting pathological αSyn, in patients with PD. The primary outcome measures were adverse event frequency and change in anti-αSyn antibody titers in blood and cerebrospinal fluid (CSF). Exploratory outcomes were changes in clinical scales and biomarker-based target engagement as measured by seed amplification assays. Twenty patients were randomized 7:3 (UB-312:placebo) into 300/100/100 μg or 300/300/300 μg (weeks 1, 5 and 13) intramuscular prime-boost dose groups. Safety was similar across groups; adverse events were mostly mild and transient. Two patients experienced three serious adverse events in total, one possibly treatment related; all resolved without sequalae. Anti-αSyn antibodies in serum from 12/13 and CSF from 5/13 patients who received three UB-312 doses confirmed immunogenicity. Mean serum titers (in log-dilution factor) increased from baseline by 1.398 and 1.354, and peaked at week 29 at 2.520 and 2.133, for 300/100/100 μg and 300/300/300 μg, respectively. CSF titers were 0 at baseline and were 0.182 and 0.032 at week 21, respectively. Exploratory analyses showed no statistical differences in clinical scales but a significant reduction of αSyn seeds in CSF of a subset of UB-312-treated patients. These data support further UB-312 development. ClinicalTrials.gov:NCT04075318.

Investigation of the pathogen-specific antibody response in periprosthetic joint infection.

Periprosthetic joint infections (PJIs) are a very demanding complication of arthroplasty. Diagnosis of PJI and pathogen identification pose considerable challenges in clinical practice. We hypothesized that the pathogen-specific immune response to PJI reflects the infection process, provides clinically relevant information on disease course, and has the potential to further optimize antimicrobial therapy. We conducted a prospective matched cohort pilot study with 13 patients undergoing two-stage septic revision arthroplasty (PJI patients) between 06/2020 and 06/2021, as well as 11 control patients undergoing one-stage aseptic revision arthroplasty (Non-PJI patients). Pre-, intra- and postoperative serum samples were collected at standardized time points. We developed a custom Luminex®-based quantitative bead-based suspension array (Infection Array; IA), and used it for simultaneous measurement of antibody specificities against 32 pathogens commonly associated with PJI in 267 serum samples. The IA was able to trace the dynamics of the pathogen-specific humoral immune response in all patients against PJI-related pathogens, prominently coagulase-negative staphylococci and streptococci. Pathogen-specific serum antibody titers declined in 62% of PJI patients over the course of treatment, while no changes in antibody titers were observed in 82% of Non-PJI patients during this study. Our serological data strongly suggested that antibody signatures reflect an immune response to microbial invasion. Our results provide insights into the pathophysiology of PJI and information on the individual disease courses. The IA is therefore a promising and novel serological tool of high resolution for monitoring the immunoproteomic footprints of infectious pathogens in the course of PJI.

Longitudinal changes in serum immunoglobulin G testing in patients with fibrotic avian hypersensitivity pneumonitis

BackgroundEvaluation of the antigen responsible for fibrotic hypersensitivity pneumonitis (HP) is challenging. Serum immunoglobulin (Ig) G testing against HP-associated antigens is performed. Although single-serum IgG testing has been investigated, multiple-serum IgG testing has not yet been studied.MethodsThis study included patients who underwent histopathological examination and positive inhalation challenge test as well as those with moderate or high HP guideline confidence level. Serum IgG testing against pigeon serum was conducted twice using two methods: enzyme linked-immunosorbent assay (ELISA) and ImmunoCAP. The association between changes in serum IgG antibody titers and changes in forced vital capacity (FVC) and other parameters was investigated.ResultsIn this study, 28 patients (mean age, 64.5 years; mean FVC, 85.3%) with fibrotic avian HP were selected, of whom 20 and 8 underwent surgical lung biopsy and transbronchial lung cryobiopsy, respectively. Of the 28 patients, 19 had been keeping birds for more than 6 months. A correlation was observed between the annual changes in serum IgG antibody titers by ELISA and changes in relative FVC (r = − 0.6221, p < 0.001). Furthermore, there was a correlation between the annual changes in serum IgG antibody titers by ImmunoCAP and changes in relative FVC (r = − 0.4302, p = 0.022). Multiple regression analysis revealed that the change in serum IgG antibody titers by both ELISA and ImmunoCAP also influenced the relative FVC change (p = 0.012 and p = 0.015, respectively). Moreover, 13 patients were given additional treatments between the first and second blood test; however, the additional treatment group was not significantly different in relative FVC change compared to the group with no additional treatment (p = 0.982).ConclusionsIn patients with fibrotic avian HP, the annual changes in serum IgG testing were correlated with FVC changes, highlighting the importance of serum IgG testing over time.

Elucidating the role of macrophage galactose-type lectin 1 (MGL-1) in the pathogenesis and resolution of SARS-CoV2

Abstract The C-type lectin receptor (CLR) family plays an important role in mediating the innate immune responses to some viruses. The Macrophage galactose-type lectin (MGL), or CLEC10, is a CLR that binds SARS-CoV-2 Spike. This binding event is dispensable for virus entry but has been implicated in an increased inflammatory response. Downstream immune responses relevant to host protection against SARS-CoV-2 are not well described. We investigated the role of MGL in disease pathogenesis by utilizing MGL-1 deficient mice (KO) and wild type (WT) control mice. Male and female mice were intranasally infected with the mouse-adapted SARS-CoV-2 strain CMA3p20 for 3 and 7-days. Lung tissues were assessed for viral load, pathology, and changes in leukocyte populations. Viral load was similar in mouse strains at 3 days post-infection (dpi), while virus persisted in MGL-1-/-, but not WT, at 7 days. This observed difference was more pronounced in female mice. Histology analysis indicated no difference in lung pathology between wild type and MGL deficient mice at 3 dpi. Immunohistochemistry and flow cytometric analysis of lung tissue for CD3 also indicated similar numbers and distribution of T cell populations. By using full spectrum flow cytometry, preliminary clustering analysis shows an increase in activated B cells and plasma cells in MGL-1-/- compared to WT mice. We are exploring the implications of altered B cell populations by investigating changes in antibody titers and isotypes.

COVID-19 antibody titers after tixagevimab–cilgavimab injection in patients with hematologic diseases; a single-center, prospective study

Knowledge of the SARS-CoV-2 antibody titers induced by tixagevimab–cilgavimab in patients with hematologic diseases remains insufficient. Here, we performed a single-center, prospective study to reveal the changes in antibody titer after administration of tixagevimab–cilgavimab in 78 patients with hematologic diseases. The median peak titer was 155.4 U/mL, and the median AUC was 46556 days·U/mL. First, we compared several characteristics between patients with low titers (peak titer ≤ 155.4 U/mL) and high titers (peak titer > 155.4 U/mL). We extracted 6 factors (patient age, sex, ECOG-PS, serum albumin level, and cross-sectional area and computed tomographic number of the psoas major muscle) as candidates influencing the antibody titers. Multiple regression analysis revealed that antibody titer was closely associated with these 6 factors (contribution rate = 0.76, p = 0.02). Our data support the inability of tixagevimab–cilgavimab to induce sufficient antibody titers against SARS-CoV-2, especially in older, frailer, female patients.

Relationship of various COVID-19 antibody titer with individual characteristics and prediction of future epidemic trend in Xiamen City, China.

Reinfection of coronavirus disease 2019 (COVID-19) has raised concerns about how reliable immunity from infection and vaccination is. With mass testing for the virus halted, understanding the current prevalence of COVID-19 is crucial. This study investigated 1,191 public health workers at the Xiamen Center for Disease Control, focusing on changes in antibody titers and their relationship with individual characteristics. The study began by describing the epidemiological characteristics of the study participants. Multilinear regression (MLR) models were employed to explore the associations between individual attributes and antibody titers. Additionally, group-based trajectory models (GBTMs) were utilized to identify trajectories in antibody titer changes. To predict and simulate future epidemic trends and examine the correlation of antibody decay with epidemics, a high-dimensional transmission dynamics model was constructed. Analysis of epidemiological characteristics revealed significant differences in vaccination status between infected and non-infected groups (χ2=376.706, P<0.05). However, the distribution of antibody titers among the infected and vaccinated populations was not significantly different. The MLR model identified age as a common factor affecting titers of immunoglobulin G (IgG), immunoglobulin M (IgM), and neutralizing antibody (NAb), while other factors showed varying impacts. History of pulmonary disease and hospitalization influenced IgG titer, and factors such as gender, smoking, family history of pulmonary diseases, and hospitalization impacted NAb titers. Age was the sole determinant of IgM titers in this study. GBTM analysis indicated a "gradual decline type" trajectory for IgG (95.65%), while IgM and NAb titers remained stable over the study period. The high-dimensional transmission dynamics model predicted and simulated peak epidemic periods in Xiamen City, which correlated with IgG decay. Age-group-specific simulations revealed a higher incidence and infection rate among individuals aged 30-39 years during both the second and third peaks, followed by those aged 40-49, 50-59, 18-29, and 70-79 years. Our study shows that antibody titer could be influenced by age, previous pulmonary diseases as well as smoking. Furthermore, the decline in IgG titers is consistent with epidemic trends. These findings emphasize the need for further exploration of these factors and the development of optimized self-protection countermeasures against reinfection.

Anti-spike protein IgG antibody responses up to 3 months after the third dose of the BNT162b2 mRNA vaccine in medical care workers.

This study aimed to assess the changes in anti-spike protein IgG antibody titer over time following mRNA vaccination (BNT162b2) against severe acute respiratory syndrome coronavirus 2. We monitored IgG levels in 23 medical care workers (MCWs) for up to 3 months after administering the third dose of BNT162b2. Blood samples were periodically collected from all participants. Following the third dose, the median antibody titer increased to 252 and 327% compared with antibody levels at 1 and 3 months after the second dose, respectively. Additionally, compared with 1 month after the second dose, the median antibody titer decreased to 30.2 and 9.8% at 3 and 6 months, respectively, and to 39.1% at 3 months, compared with 1 month after the third dose. Antibody levels declined quickly after the second dose but declined more slowly after the third dose, showing a booster effect. This study provides insights into the immunogenicity of booster doses and time intervals for booster vaccination strategies.

Rituximab may affect T lymphocyte subsets balance in primary membranous nephropathy

BackgroundThe aim of this study was to investigate the effects and significance of rituximab (RTX) on the levels of T lymphocyte subsets in patients diagnosed with primary membranous nephropathy (PMN).MethodsA total of 58 PMN patients and 25 healthy donors were chosen as the subjects. Among the PMN patients, 40 individuals received RTX treatment and completed at least 6 months of follow-up. All subjects underwent flow cytometry analysis to determine the peripheral blood lymphocyte subsets. The changes in anti-PLA2R antibody titers and 24-hour urinary protein levels were evaluated by ELISA and Biuret method before and after treatment.Results(1) The PMN group exhibited a significantly greater percentage of peripheral blood CD3−CD19+ B cells than the healthy group, which is consistent with the findings of previous reports. Additionally, compared with those in the peripheral blood of healthy individuals, the numbers of CD4+ central memory T cells, CD4+ effector memory T cells, CD4+/CD8+, and CD4+CD25+ T cells in the PMN peripheral blood were markedly greater. However, the number of peripheral blood Treg cells was reduced in the PMN group. (2) After 6 months of RTX treatment, PMN patients exhibited significant decreases in anti-PLA2R antibody titers, 24-hour urinary protein levels, and peripheral blood CD3−CD19+ B cells. Importantly, RTX administration decreased CD4+CD25+ T cells and CD4+/CD8+ in the peripheral blood of PMN patients and improved Treg cell levels. (3) RTX treatment induced alterations in the CD4+ T lymphocyte subsets in PMN patients, which did not correlate with B lymphocyte counts or anti-PLA2R antibody titers.ConclusionsRTX treatment might have a beneficial impact on cellular immunity by effectively restoring the balance of CD4+ T lymphocyte subsets in PMN patients, which is beyond its effects on B cells and antibody production.Trial registrationThe research was registered at the First Affiliated Hospital of Soochow University. Registration Number: MR-32-23-016211. Registration Date: May 31, 2023.

Sero and Carriage Epidemiology of Pertussis in Urban and Rural Regions in Vietnam.

The underestimation of the pertussis burden prompted our study to investigate the prevalence of recent pertussis infection, its associated factors, and antibody titer changes in the same individuals in Vietnam. Two cross-sectional surveys were conducted in Nha Trang in 2017 and Quang Ngai in 2019, representing high- and low-vaccine-coverage areas, respectively. Serum anti-pertussis toxin immunoglobulin-G (anti-PT IgG) ≥ 62.5 IU/mL by ELISA indicated infection in the previous 12 months. In Nha Trang, the participants of the 2017 survey were followed up in 2019. Logistic regression was used to determine the odds ratios for the characteristics associated with anti-PT IgG ≥ 62.5. The age-stratified prevalence in patients aged >2 years ranged from 2.1% (age 26-35) to 9.6% (3-5) in Nha Trang (2017) and from 7.2% (age 26-35) to 11.4% (6-15) in Quang Ngai. The prevalence tended to be higher in Quang Ngai across all age groups. Cough, recent antibiotic use, and smoking in Nha Trang were positively associated with an anti-PT IgG of ≥62.5, and having been diagnosed with pertussis and persistent cough with paroxysms/whoop in Quang Ngai were positively associated with an anti-PT IgG of ≥62.5. No nasopharyngeal swabs were positive for Bordetella pertussis using real-time PCR. The geometric mean of the IgG titer ratio from 2019 to 2017 was 1.45 in the paired samples. This study emphasizes Bordetella pertussis circulation across all age groups in both low- and high-vaccine-coverage settings in Vietnam, underscoring the need for continuous and standardized surveillance for a comprehensive understanding of its epidemiology.

Changes in antibody titer after four and five doses of the SARS-CoV-2 vaccine in Japanese post-kidney transplant patients.

Immunosuppressed patients exhibit low antibody acquisition rates following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. Kidney transplant recipients previously exhibited low antibody acquisition rates after two vaccine doses, which increased after the third dose. We evaluated antibody titers of Japanese post-kidney transplant patients after the fourth and fifth vaccinations. Antibody titers for SARS-CoV-2 spike protein were measured between 3 weeks and 3 months after the fourth or fifth vaccination. Increased antibody acquisition rates were observed after the fourth (75.0% antibody-positive) and fifth (81.5% antibody-positive) vaccinations. The antibody-acquired group after the fourth vaccination exhibited a higher body mass index and estimated glomerular filtration rate (eGFR) than the non-acquired group. A higher eGFR was associated with antibody acquisition after the fifth vaccination. In Japanese post-kidney transplant patients, the antibody acquisition rate increased with each vaccine additional dose. Additional vaccinations are recommended to protect against SARS-CoV-2 infection.

Immune Responses to Anti-Hepatitis C Virus Antibodies during Pre-Liver Transplantation Direct-Acting Antiviral Therapy in Hepatitis C Virus-Infected Recipients Associated with Post-Liver Transplantation Allograft Injury.

The impact of antibody responses following direct-acting antiviral (DAA) therapy in hepatitis C virus (HCV)-infected recipients before and after liver transplantation (LT) is still undetermined. In this observational cohort study, we aimed to explore the association between changes in anti-HCV antibody titers following pre-LT DAA therapy and allograft injury, including biliary complications (BCs) and acute cellular rejection (ACR). A total of 153 cases were enrolled from January 2015 to February 2021. Serum anti-HCV antibody titers were assessed before and after (day 30) LT. Among all recipients, 31/153 (20.3%) had pre-LT DAA therapy (the DAA group) and 122/153 (79.7%) did not undergo pre-LT DAA therapy (the DAA-naïve group). A higher incidence of post-LT BCs was observed in the DAA group (p = 0.028). Compared with the DAA-naïve group, the DAA group had a significantly higher mean level of anti-HCV titer upregulation (p = 0.0024); furthermore, among the recipients with BCs (n = 28) and ACR (n = 41), those in the DAA group exhibited significantly higher mean levels of anti-HCV antibody titer upregulation (p < 0.005). In conclusion, we speculate that the upregulation of anti-HCV antibody titers, which might have been induced via the restoration of HCV-specific immune responses through pre-LT DAA therapy, was associated with post-LT allograft injury.

The prevalence of post-COVID-19 vaccination syndrome and quality of life among COVID-19-vaccinated individuals

BackgroundThere were many studies conducted to determine how immunization affects people with long-term COVID. The results of those studies have caused debate as they gave rise to varying outcomes. Some evidence indicates a change in, an improvement in, a continuation of, or even a worsening of long-term COVID symptoms following vaccination. The ratio of change in antibody titers was noticeably larger in the group of people whose illnesses became worse. Hence, this study aimed to explore potential post-COVID-19 vaccination syndrome (PCVS) in vaccinated individuals and also to assess their quality of life (QoL). MethodologyBetween September 2021 and May 2023, an ambidirectional, descriptive, follow-up cohort study was conducted, enrolling participants who were 18 years of age or older, met the vaccination requirements established by the Ministry of Health and Family Welfare, Government of India, and had completed the primary immunization series with the AZD1222® or BBV152® vaccine. The prevalence of PCVS and the QoL measured using EQ-5D-5L were assessed at 1 month, 6 months, and 12 months post-COVID-19 vaccination. ResultsAZD1222® vaccine was received by 84.28% (343) of the participants, and BBV152® vaccine was received by 15.72% (64) of the study participants. A month after the primary vaccination series, 52.8% (215) of the total participants had at least 1 PCVS, 39.8% (162) at 6 months, and 64.6% (263) at 12 months. Among those who had received vaccinations, the QoL increased at 6 months to 0.975±0.08 and declined at 12 months to 0.94±0.13 from 0.949±0.13 at 1 month after receiving a primary immunization. The overall prevalence of PCVS between AZD1222®-vaccinated individuals and BBV152®-vaccinated individuals at a month post-vaccination was 54.5% vs. 43.8%, at 6 months it was 41.1% vs. 32.8%, and at 12 months it was 65.59% vs. 59.4%. The QoL between AZD1222®-vaccinated individuals and BBV152®-vaccinated individuals at a month post-vaccination was 0.95±0.13 vs. 0.95±0.126, at 6 months it was 0.98±0.08 vs. 0.97±0.07, and at 12 months it was 0.94±0.12 vs. 0.92±0.20. However, there was no statistically significant difference in the prevalence of PCVS and QoL between AZD1222® and BBV152®-vaccinated individuals.The percentage of participants who had at least one PCVS was 83.9% (146) in the group that got booster doses and 50.2% (117) in the group that did not. The QoL was 0.9±0.15 in the group receiving booster dosages and 0.96±0.11 in the group not receiving them. There was a statistically significant difference in the prevalence of PCVS and QoL between booster dose recipients and no booster dose recipients. ConclusionIn the study, we observed the prevalence of PCVS and was similar to long-term COVID; it declined over time and increased following booster immunization. Contrary to PCVS prevalence, QoL rises with time and falls after booster doses. There is no difference in the prevalence of PCVS and the quality of life among AZD1222® and BBV152®.

Altered antibody titers in patients with neuromuscular diseases after high-dose intravenous immunoglobulin therapy

We investigated the changes in antibody titers after intravenous immunoglobulin (IVIg) administration in patients with neuromuscular diseases. Among patients who received IVIg from April 1, 2020, to August 31, 2022, we retrospectively evaluated 15 patients with antibody measurements before and after IVIg administration for any rise in the following antibody levels and examined the data for subsequent changes of false positive results to negative ones. The levels of anti SS-A, anti-thyroglobulin, anti-thyroid peroxidase, anti-glutamic acid decarboxylase, HBs, and HBc antibodies transiently increased after IVIg administration and showed false-positive results. However, levels of rheumatoid factor and anti-nuclear and antineutrophil cytoplasmic antibodies were not elevated. The false-positive results became negative after 3 months. Here, we report on the changes in antibody levels before and after IVIg administration and note that levels of hepatitis B virus-related antibodies and various autoantibodies transiently rise after IVIg administration.

Anti-A and anti-B titers, age, gender, biochemical parameters, and body mass index in Japanese blood donors.

It has been reported that anti-A and anti-B (ABO antibody) titers decrease with age, but little is known about the association between ABO antibody titers and physiologic/biochemical parameters such as body mass index (BMI), gamma-glutamyl transpeptidase (GGT), and total cholesterol (T-Cho). We investigated the present situation of ABO antibody titers among healthy blood donors in Japan and the physiologic/biochemical factors that may be associated with changes in ABO antibody titers. Plasma from 7450 Japanese blood donors was tested for ABO antibody titers using ABO reverse typing reagents by an automated microplate system; donor samples were classified into low, middle, and high titers according to the agglutination results obtained with diluted plasma samples. Multivariate regression analysis was performed to analyze the association between ABO antibody titers and age, gender, biochemical parameters (alanine transaminase [ALT], GGT, globulin, T-Cho, and glycosylated albumin [GA]), and BMI according to the ABO blood groups. A significant correlation between ABO antibody titers and age/gender, except for gender in anti-A of blood group B donors, was observed. BMI showed significant but negative correlations with anti-A and anti-B (β = -0.085 and -0.062, respectively; p < 0.01) in blood group O donors. In addition, significant but negative correlations between GGT and T-Cho with anti-B of blood group A donors (β = -0.055 and -0.047, respectively; p < 0.05) were observed. Although differences existed among the ABO blood groups, ABO antibody titers seem to be associated with physiologic and biochemical parameters of healthy individuals.

Exploring Appropriate Strategies for Vaccination against Classical Swine Fever under a Dynamic Change in Antibody Titer in Sows after Starting Vaccination in a Japanese Farm Setting

After 26 years of absence in Japan, a classical swine fever (CSF) outbreak occurred at a domestic pig farm in 2018. Vaccination against the CSF virus with a live attenuated vaccine at pig farms was restarted in October 2019, which was 13 years after the 2006 ban on vaccination. An individual-based simulation model for CSF antibody dynamics was developed to determine an effective CSF vaccination strategy for pig populations. In creating a simulated pig herd, the optimal vaccination age of piglets and the effect of vaccinating piglets twice were evaluated. Additionally, the herd immunity was monitored every 6 months for 4 years after the start of vaccination, and the effects of intensive sow replacement policies were assessed. The simulation results indicated that the vaccination age should be delayed relative to the age used before the 2006 ban on vaccination and shifted earlier, from 8 weeks to 6 weeks, as time elapses. The simulations indicated a tradeoff in protection between the weaning period (i.e., maternally derived antibodies) and the fattening period (i.e., by vaccine-induced antibodies). Mixing sows with high and low antibody titers, particularly sows that received the first vaccination and those born after the start of vaccination, resulted in a high variation in antibody titer among pigs on the farm. This study also clarified the positive effect of intensive sow replacement strategies on shortening the period in which sows show diverse titers. Differences in sow replacement rates among farms and/or the time lag in starting vaccination in different prefectures result in heterogeneity in herd immunity in Japan; thus, herd immunity status should be examined at every farm using this simulation model.

Review on Diagnostic Methods of Infectious Coryza in Chickens

The total poultry population in Ethiopia is estimated to be 51.35 million. The Poultry sector is a fastest growing among the animal production activities offers an opportunity to feed the fastest growing human population and provide income resources for poor farmers. There are different diseases which can affect chicken. Among the bacterial diseases, Infectious Coryza (IC) is an acute and contagious respiratory disease of chickens caused by the bacteria, Avibacterium paragallinarum. IC is distributed worldwide and typically transmitted by direct contact, airborne droplets and contamination of drinking water. But Egg transmission does not occur. The initial step in the pathogenesis of infectious coryza is adherence to and colonization of the nasal mucosa. The diagnosis can be based on a history of rapid disease spread, clinical symptoms, and pathological changes caused by IC. Diagnostic methods for IC include direct isolation, the HI test for serovar A and Polymerase Chain Reaction (PCR). Diagnosis of Avibacterium paragallinarum have been proposed as alternatives to conventional serotyping by the Page scheme. The HI test, which is one of the most widely used serological test, is often utilized to detect changes in antibody titers in cases of field infection or vaccination, and is useful for evaluating the prevalence of IC in certain areas. Rapid and accurate detection of respiratory IC has become a challenge because of the involvement of more than one agent with similar clinical signs and lesions, which complicates diagnostic decisions, as well as treatment and control strategies.