Senecavirus A (SVA) is a major viral pathogen causing disease in pigs, and effective monitoring of SVA infection is critical for disease control. In this study, we aimed to develop a reliable ELISA method for rapidly detecting neutralizing antibodies against SVA. We used HEK293F cells to express an SVA-specific porcine Fab antibody and verified the biological activity of the Fab antibody by indirect ELISA, immunofluorescence assay, virus neutralization test, and Western blotting. The Fab antibody was biotinylated and used as a competitive antibody to establish a competitive ELISA (C-ELISA) for detecting neutralizing antibodies against SVA. We then evaluated the C-ELISA in terms of sensitivity, specificity, repeatability, and result agreement rate with the VNT. The results showed that we successfully prepared an SVA-specific porcine Fab antibody, which showed high affinity for SVA. We named this antibody 1M33Fab and designated it as Bio-1M33Fab after biotin labeling. The assay conditions were optimized as follows: the coating concentration of SVA particles being 1 μg/mL, the working concentration of Bio-1M33Fab being 0.5 μg/mL, the optimal serum dilution of 1:10, and the optimal dilution of enzyme-labeled avidin being 1:30 000. At a percent inhibition (PI) of 47%, the assay demonstrated the highest sensitivity (96.88%) and specificity (100%), with no cross-reactivity observed with the positive sera of major porcine viral diseases. The intra-assay coefficient of variation ranged from 1.12% to 7.34%, while the inter-assay coefficient of variation ranged from 1.10% to 8.97%, indicating good repeatability. In the detection of 224 clinical pig serum samples, C-ELISA and VNT showed a result agreement rate of 93.75%. In conclusion, we successfully develop a C-ELISA method for detecting neutralizing antibodies against SVA by using a porcine-derived Fab antibody, which lays a foundation for the development of detection kits.
Animals ; Swine ; Antibodies, Neutralizing/immunology* ; Enzyme-Linked Immunosorbent Assay/methods* ; Immunoglobulin Fab Fragments/immunology* ; Antibodies, Viral/immunology* ; Picornaviridae/immunology* ; Humans ; HEK293 Cells ; Swine Diseases/diagnosis* ; Picornaviridae Infections/diagnosis*

In this study, we constructed a series of recombinant Fc variants of immunoglobulin G4 (IgG4), screened the fragment crystallizable (Fc) variants with significantly prolonged serum half-lives, and analyzed the relationship between mutation site and half-life, aiming to provide a theoretical basis for the development of IgG4 antibodies and Fc fusion protein-based drugs. Nine gene sites were selected for mutation, and different mutation sites were combined. The variant expression plasmids pET24b-Fc were constructed by molecular cloning and point mutation. The plasmids were transformed into Escherichia coli BL21(DE3) for the expression of different recombinant proteins of Fc. Fc2 and Fc3 variants had slightly lower recombinant protein yields, and the expression of other variants was not affected. The toxicity of different Fc variants was determined by cell counting kit-8 (CCK-8) and calcein acetoxymethyl ester/ propidium iodide (calcein AM/PI) in vitro and enzyme-linked immuno sorbent assay (ELISA) in vivo. The results showed that the recombinant Fc variants had good biocompatibility and safety. Finally, the Fc variants were labeled with fluorescent markers, and the effects of different mutations on their serum half-lives were investigated by in vivo experiments. The Fc5 variant with prolonged serum half-life was successfully screened out, which provided a theoretical and practical basis for the optimal design of IgG4 subtype antibody and Fc fusion protein drugs.
Immunoglobulin G/blood* ; Immunoglobulin Fc Fragments/biosynthesis* ; Half-Life ; Animals ; Escherichia coli/metabolism* ; Humans ; Recombinant Fusion Proteins/biosynthesis* ; Recombinant Proteins/biosynthesis* ; Mice

OBJECTIVE: To investigate the clinical characteristics and prognosis of patients with IgD multiple myeloma (MM). METHODS: The clinical data of 8 patients with IgD MM admitted to Gansu Provincial Hospital from September 2013 to February 2023 were collected, and their clinical characteristics and prognosis were retrospectively analyzed and summarized. RESULTS: Among the 8 enrolled patients, there were 4 males and 4 females, with a median age of 60 (44-74) years. All patients had symptoms of renal insufficiency and anemia. There were 3 cases of bone invasion, 3 cases of splenomegaly, 7 cases of IgD-λ type, and 1 case of IgD-κ type. FISH examination was performed in 7 cases, and 6 of them were positive for 1q21 . There were 6 cases in DS stage III and 2 cases in DS stage II; According to ISS staging, there were 6 cases in stage III, 1 case in stage II, and 1 case in stage I; According to R-ISS staging, there were 5 cases in stage III and 3 cases in stage II. All patients received bortezomib-based combination chemotherapy, with 1 case undergoing autologous stem cell transplantation (ASCT) and 2 cases receiving daratumumab in combination. The median treatment period was 6 (1-15) cycles. The short-term efficacy was evaluated after 4-6 courses of treatment. Among the 6 patients with assessable efficacy, 1 case experienced disease progression (PD), and 5 cases achieved complete remission (CR). The median follow-up time was 26 (11-33) months, and the median progression-free survival (PFS) and median overall survival (OS) of the patients were 11.25 (3-26) months and 18.5 (4-33) months, respectively. Among the 8 patients, 4 cases died. Among the deceased patients, 3 cases were in R-ISS stage III and 3 cases were 1q21 positive. 2 of the 5 patients with early CR died due to disease progression. CONCLUSION The incidence of IgD MM is low, the symptoms of early renal damage, blood system damage and bone erosion in IgD MM patients are obvious, and the median survival time is short. ASCT and / or daratumumab may bring lasting relief for IgD MM patients, but large-scale clinical studies are still needed.
Humans ; Multiple Myeloma/therapy* ; Middle Aged ; Male ; Female ; Aged ; Prognosis ; Immunoglobulin D ; Adult ; Retrospective Studies

OBJECTIVE: To analyze the origin and influencing factors the titer of ABO blood group antibody in neonates. METHODS: A total of 303 newborn blood samples collected in our hospital from August 2023 to March 2024 were selected for the detection of ABO blood group settings and the determination of the total titers of IgG and IgM blood group antibodies in plasma. IgM antibodies were treated with dithithreitol (DTT) to determine the titers of IgG antibodies. The total titer of the blood group antibody was compared with that of the IgG antibody. The clinical data of mothers and newborns were collected, and the correlation between the antibody titer and these clinical data was analyzed. RESULTS: Among the 303 newborn specimens, 14 cases (4.62%) were identified to possess blood group antibodies. The influence of the maternal ABO blood group on the generation of high-potency blood group antibodies in newborns was observed to follow the order of O>B>A>AB, with a significant statistical difference ( P < 0.01). Of the 123 (40.59%) newborns born to mothers of type O, 121 (98.37%) had blood group antibody titers > 2. Of the 20 (6.60%) newborns born to mothers of type AB, all 20 (100.00%) had blood group antibody titers < 2. Among 89 (29.37%) mothers of type A and 71 (23.43%) mothers of type B, the titer of 100% newborn blood group antibody was less than 2, when the newborn blood group was incompatible with the mother's blood group; the titer of the newborn blood type antibody was higher or lower, when the newborn blood type was compatible with the mother's blood type. The titer of the newborn blood group antibodies is related to the number of pregnancies of the mothers and has no association with other clinical data (such as the mother's number of obortions), the number of production, fetal gestation age. CONCLUSION The majority of ABO blood group antibodies in neonates are IgG antibodies from the mothers, and few are produced by the neonates themselves. In some neonates, IgG anti-A and/or anti-B can agglutinate with anti-stereotyped cells at room temperature. The maternal ABO blood type is the primary factor influencing the titer of the newborn blood type. The number of maternal pregnancies is a factor affecting the high titer ABO blood group antibodies in newborns.
Humans ; Infant, Newborn ; ABO Blood-Group System/immunology* ; Female ; Immunoglobulin G/blood* ; Immunoglobulin M/blood* ; Pregnancy ; Blood Grouping and Crossmatching

OBJECTIVE: To investigate the serological prevalence of high-titer IgG antibodies against 2019-nCoV among voluntary blood donors in Zunyi. METHODS: The blood plasma specimens were diluted at 1∶160 or 1∶320, then tested for the presence of 2019-nCoV IgG antibodies by using an indirect enzyme-linked immunosorbent assay(ELISA). The differences of antibody reactive rate among different genders, ages, and blood types were analyzed. RESULTS: 1 523 reactive specimens were identified in 5 378 specimens which were diluted at a ratio of 1∶160. Similarly, 329 reactive specimens were identified in 2 988 diluted at 1∶320. The overall reactive rate for antibodies was 22.1%. It was observed that females, individuals over the age of 40, and those with blood type AB exhibited higher high-titer antibody reactive rate. CONCLUSION After entering a new stage of 2019-nCoV infection prevention and control, there is a relatively high detection rate of high-titer 2019-nCoV IgG antibodies among voluntary blood donors in Zunyi. The reactive rate of antibodies varies among different genders, ages, and blood types.
Humans ; Blood Donors ; Immunoglobulin G/blood* ; Antibodies, Viral/blood* ; SARS-CoV-2/immunology* ; COVID-19 ; Female ; Enzyme-Linked Immunosorbent Assay ; Adult ; China ; Male ; Middle Aged

OBJECTIVE: To retrospectively analyze the clinical characteristics, prognosis and prognostic factors of patients with light-chain (AL) amyloidosis, so as to provide reference for the diagnosis and treatment of AL amyloidosis. METHODS: Clinical data of 52 patients diagnosed with AL amyloidosis at two hospitals from January 2017 to November 2022 were collected. The clinical characteristics, differences in clinical indexes between the deceased group and the survival group were analyzed. Kaplan-Meier curves were used for overall survival (OS) analysis, and Cox regression models were used to analyze the factors affecting the prognosis. RESULTS: The median age of the 52 patients at diagnosis was 61(41-81) years old, and 63.5% of the patients were male. Heart (69.2%) and kidney (67.3%) were the most involved organs, and 67.3% of the patients had two or more organs involved. Most patients (71.2%) received chemotherapy regimens containing bortezomib, including 5 patients (9.6%) who received treatment with daratumumab in combination with bortezomib. The proportion of male patients (81.0%), the proportion of patients with cardiac involvement (95.2%), and the proportion of patients with Mayo 2012 stage ≥III (95.2%), as well as the levels of hs-cTnI and NT-proBNP in the deceased group were significantly higher than those in the survival group ( P < 0.05). The median OS time of the enrolled patients was 33.4(2.6-60.2) months, with 1-year, 2-year, 3-year and 5-year OS rates of 83.7%, 79.3%, 58.9% and 32.7%, respectively. The Kaplan-Meier survival curve analysis revealed that patients with male gender (P =0.040), NT-proBNP ≥3 600 ng/L ( P < 0.001), Mayo 2012 stage ≥III ( P < 0.001), and cardiac involvement (P =0.008) had poor prognosis and shorter overall survival (OS) time. The multivariate regression analysis showed that Mayo 2012 stage ≥III was an independent risk factor for prognosis. CONCLUSION In recent years, the survival rate of patients with AL amyloidosis has improved significantly, but the 5-year survival rate is still relatively low. Cardiac biomarkers (NT-proBNP and hs-cTnI) and Mayo 2012 stage at diagnosis continue to provide important prognostic information. Bortezomib-based regimens were used as the primary treatment in most patients, and the addition of daratumumab is becoming increasingly common.
Humans ; Retrospective Studies ; Prognosis ; Middle Aged ; Male ; Female ; Aged ; Immunoglobulin Light-chain Amyloidosis/diagnosis* ; Adult ; Aged, 80 and over ; Kaplan-Meier Estimate

OBJECTIVE: To explore the role of semaphorin 4D (Sema4D) in immunoglobulin A (IgA) -mediated immune abnormalities in B lymphocytes of pediatric Henoch-Schonlein purpura (HSP). METHODS: One hundred HSP children admitted to Hengshui People's Hospital from January 2022 to January 2023 were selected as HSP group, and one hundred healthy children as control group. Sema4D expression was detected, and the relationship between Sema4D expression in children's serum and skin lesions and clinical characteristics of children was analyzed. Sema4D expression on the surface of lymphocytes of HSP children was detected. Different concentrations of human recombinant Sema4D protein was used to stimulate peripheral blood mononuclear cells in HSP children in vitro. The expression level of IgA in the supernatant was detected to verify whether Sema4D mediates immune abnormalities through IgA secreted by B lymphocytes. RESULTS: The Sema4D level in the HSP group was significantly higher than that in the control group (P <0.001). Sema4D level in HSP children with severe, renal involvement, and joint involvement was higher than those with mild to moderate disease, and no renal or joint involvement (all P <0.001). Compared with control group, IgA level, CD8 ⁺ T lymphocyte proportion, and CD19 ⁺ B lymphocyte proportion in the HSP group were significantly higher but CD4 ⁺ T lymphocyte proportion was lower (all P <0.001). The expression levels of Sema4D on the surface of CD4 ⁺ T lymphocytes, CD8 ⁺ T lymphocytes, and CD19 ⁺ B lymphocytes in the HSP group were significantly higher than those in the control group (all P <0.001). With the increase of human recombinant Sema4D protein concentration, the level of IgA expression in HSP children gradually increased (P <0.05). Correlation analysis showed that Sema4D was significantly positively correlated with IgA (r =0.667). CONCLUSION HSP children show high expression of Sema4D, especially on the surface of T and B lymphocytes. The shedding of Sema4D from membrane surface may stimulate B lymphocytes to secrete IgA by binding to CD72, leading to immune abnormalities.
Humans ; IgA Vasculitis/immunology* ; Semaphorins/metabolism* ; B-Lymphocytes/metabolism* ; Immunoglobulin A/immunology* ; Child ; Antigens, CD/metabolism* ; Male ; Female ; Child, Preschool

BACKGROUND: Epstein-Barr (EB) virus infection stimulates the production of vascular endothelial growth factor (VEGF), which contributes to the progression of angiogenesis. Angiogenesis plays an important role in the development of atherosclerosis. Since serum anti-early antigen EB virus IgG (EBV EA-IgG) titer is a sign of active EB virus infection, EBV EA-IgG titer could be associated with atherosclerosis. The number of minor (T) alleles in VEGF polymorphism rs3025039 has been reported to be inversely associated with serum VEGF concentration, suggesting that rs3025039 might have a strong influence on the association between EBV EA-IgG titer and atherosclerosis. By focusing on the role of VEGF in the development of atherosclerosis, this study aimed to investigate the association between active EB virus infection and atherosclerosis. METHODS: A cross-sectional study of 2,661 older Japanese individuals aged 60-89 years who participated in annual health check-ups during 2017-2019 was conducted. Logistic regression was used to evaluate the association between EBV EA-IgG titer and atherosclerosis in relation to rs3025039 genotype. The influence of rs3025039 (T) allele carrier status on the association between EBV EA-IgG titer and atherosclerosis was also evaluated by using logistic regression. RESULTS: Among rs3025039 CC-homozygotes, with the lowest EBV EA-IgG titer tertile as the reference, the multivariable odds ratio (95% confidence interval) was 1.11 (0.82, 1.50) for the medium tertile and 1.07 (0.78, 1.47) for the high tertile. Among rs3025039 (T) allele carriers, the corresponding values were 1.44 (0.88, 2.36) and 1.88 (1.15, 3.05), respectively. There was a significant interaction between rs3025039 (T) allele carrier status and the association between EBV EA-IgG titer and atherosclerosis (adjusted p = 0.0497). CONCLUSION EBV EA-IgG titer was significantly positively associated with atherosclerosis only among participants who are genetically less likely to have progressive angiogenesis. An angiogenesis-related genetic factor was revealed as a determinant of the association between EBV EA-IgG titer and atherosclerosis. These findings introduce a novel concept that could explain the association between viral infection and atherosclerosis.
Humans ; Aged ; Male ; Middle Aged ; Female ; Japan/epidemiology* ; Atherosclerosis/virology* ; Aged, 80 and over ; Vascular Endothelial Growth Factor A/genetics* ; Epstein-Barr Virus Infections/virology* ; Polymorphism, Single Nucleotide ; Cross-Sectional Studies ; Herpesvirus 4, Human ; Antigens, Viral/immunology* ; Antibodies, Viral/blood* ; Immunoglobulin G/blood* ; Genotype ; East Asian People

Objective:This study aims to evaluate the clinical utility of total IgE （tIgE） and specific IgE （sIgE） levels in nasal secretions for diagnosing allergic rhinitis. The investigation is enhanced through an improved method of nasal secretion collection and advanced quantum dot immunofluorescence detection technology. Methods:A total of 88 subjects were enrolled in this study, and demographic data and clinical characteristics were collected through standardized questionnaires. Anterior rhinoscope was used to check the local condition of the nasal cavity. Each participant underwent skin prick test（SPT）. The total IgE（tIgE） and sIgE in nasal secretions were quantitatively analyzed by improved nasal secretion collection strategy and quantum dot immunofluorescence method, and the correlation between them and clinical symptoms and signs was discussed. The receiver operating characteristic curve（ROC） was used to calculate the optimum threshold and detection efficiency of total IgE and sIgE in nasal secretions. Results:The improved method successfully collected nasal secretions from all subjects. Based on SPT results, participants were categorized into three groups: normal control （20 cases）, non-allergic rhinitis （22 cases）, and allergic rhinitis （46 cases）. Analysis showed that both tIgE and sIgE levels in nasal secretions correlated with nasal symptoms and signs. A tIgE level of ≥9.42 IU/mL was identified as a cut-off for allergic rhinitis diagnosis, demonstrating an 85.37% agreement with SPT results. Furthermore, cut-off values for house dust mite sIgE （≥0.34 IU/mL） and dermatophagoides Farinae sIgE （≥0.41 IU/mL） yielded a diagnostic agreement of 97.56% with SPT. Notably, two patients in the non-allergic rhinitis group tested negative for SPT but positive for dust mite sIgE in nasal secretions and exhibited positive results in the nasal provocation test, indicating potential local allergic rhinitis. Conclusion:The assessment of tIgE and mite-specific IgE levels in nasal secretions presents a rapid, reliable, and non-invasive approach for diagnosing allergic rhinitis, particularly in cases of local allergic rhinitis.
Humans ; Immunoglobulin E/analysis* ; Quantum Dots ; Male ; Female ; Adult ; Young Adult ; Middle Aged ; Rhinitis, Allergic/immunology* ; Adolescent ; Fluorescent Antibody Technique/methods* ; Case-Control Studies ; Nasal Mucosa/immunology*

Objective:To investigate the clinical diagnosis and treatment of IgG4-related disease（IgG4-RD） primarily involving the nasal cavity and skull base. Methods:A retrospective analysis was conducted on the clinical data of 8 patients with IgG4-RD primarily involving the nasal cavity and skull base who visited the Nasal and Skull Base Surgery Department at Xiangya Hospital from October 2017 to January 2024. The cohort comprised 4 males and 4 females, aged 8 to 69 years. Clinical data, laboratory examination results, imaging findings, histopathological results, and treatment plans were collected. The clinical manifestations, diagnosis, treatment and follow-up results of IgG4-RD primarily involving nasal cavity and skull base were summarized and previous literature were also reviewed. Results:The initial symptoms in the 8 patients included nasal congestion, headache, sensory function decline, and facial deformities. Three patients also had parotid and pulmonary involvement. Among the 8 patients, 4 underwent partial surgical resection combined with glucocorticoid therapy; 1 underwent partial surgical resection combined with glucocorticoid and immunosuppressant therapy; 1 received glucocorticoid therapy alone; and 2 received glucocorticoid combined with immunosuppressant therapy. Follow-up was conducted one month after treatment, lasting from 5 to 79 months. During the follow-up period, recurrence was observed in 1 patient treated with glucocorticoid combined with immunosuppressants and in 1 patient treated with glucocorticoid alone, while the other 6 patients achieved significant remission. Conclusion:The diagnosis of nasal cavity and skull base IgG4-RD requires the combination of histopathology, laboratory tests, and imaging results. Treatment primarily includes glucocorticoids or combined immunosuppressants. For patients with significant compression symptoms, sensory function impairment, or facial deformities, surgical resection is an important treatment option. Given the high risk of recurrence, early intervention, active treatment, and long-term follow-up are crucial.
Humans ; Male ; Skull Base/pathology* ; Female ; Middle Aged ; Retrospective Studies ; Aged ; Nasal Cavity/pathology* ; Adult ; Immunoglobulin G4-Related Disease/therapy* ; Immunoglobulin G ; Child ; Young Adult ; Adolescent