Integrating pretest probability for rheumatoid arthritis with likelihood ratios of RF and ACPA to improve clinical utility of rheumatoid arthritis autoantibody testing.

BACKGROUND AND AIMS: Rheumatoid arthritis (RA) manifests through various symptoms and systemic manifestations. Diagnosis involves serological markers like rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). Past studies have shown the added value of likelihood ratios (LRs) in result interpretation. LRs can be combined with pretest probability to estimate posttest probability for RA. There is a lack of information on pretest probability. This study aimed to estimate pretest probabilities for RA. MATERIALS AND METHODS: This retrospective study included 133 consecutive RA patients and 651 consecutive disease controls presenting at a rheumatology outpatient clinic. Disease characteristics, risk factors associated with RA and laboratory parameters were documented for calculating pretest probabilities and LRs. RESULTS: Joint involvement, erosions, morning stiffness, and positive CRP, ESR tests significantly correlated with RA. Based on these factors, probabilities for RA were estimated. Besides, LRs for RA were established for RF and ACPA and combinations thereof. LRs increased with antibody levels and were highest for double high positivity. Posttest probabilities were estimated based on pretest probability and LR. CONCLUSION: By utilizing pretest probabilities for RA and LRs for RF and ACPA, posttest probabilities were estimated. Such approach enhances diagnostic accuracy, offering laboratory professionals and clinicians insights in the value of serological testing during the diagnostic process.

PD-1 Targeted Antibody Discovery Using AI Protein Diffusion.

The programmed cell death protein 1 (PD-1, CD279) is an important therapeutic target in many oncological diseases. This checkpoint protein inhibits T lymphocytes from attacking other cells in the body and thus blocking it improves the clearance of tumor cells by the immune system. While there are already multiple FDA-approved anti-PD-1 antibodies, including nivolumab (Opdivo® from Bristol-Myers Squibb) and pembrolizumab (Keytruda® from Merck), there are ongoing efforts to discover new and improved checkpoint inhibitor therapeutics. In this study, we present multiple anti-PD-1 antibody fragments that were derived computationally using protein diffusion and evaluated through our scalable, in silico pipeline. Here we present nine synthetic Fv structures that are suitable for further empirical testing of their anti-PD-1 activity due to desirable predicted binding performance.

Association between celiac disease and fibromyalgia and their severity: a cross-sectional study.

Background: Fibromyalgia (FMS) is a common musculoskeletal disorder with many causes. People with fibromyalgia often have the same symptoms as people with celiac disease (CD). Demonstration of the coordination and frequency of FMS and CD is important for effective treatment. Methods: This is a single center cross-sectional clinical study. The study included 60 patients who were diagnosed with CD by the Gastroenterology Clinic based on American College of Gastroenterology (ACG) criteria. Patients were also asked to complete the Widespread Pain Index (WPI), Symptom Severity Scale (SSS), and Fibromyalgia Impact Questionnaire (FIQ) to diagnose fibromyalgia and assess its severity. The results were used to analyze the frequency of concomitance and relationship between the two diseases. Results: The relationship between the clinical types of CD and the presence of fibromyalgia was insignificant. Analysis of the relationship between the pathologic typing of biopsy and fibromyalgia frequency was insignificant. Those with antibodies more frequently met criteria for fibromyalgia (P = 0.04, P = 0.04, respectively). Conclusions: Presence of clinical extraintestinal manifestations in patients with CD should lead clinicians to consider FMS as a possible diagnosis. This points to the importance for clinicians in all subspecialties to be aware of the various symptoms and diseases associated with FMS.

A rare case of systemic lupus erythematosus-associated neuromyelitis optica spectrum disorder with cystic lesions and dual seropositivity for anti-AQP4 and anti-MOG antibodies.

Key Clinical Message: In patients with SLE, concurrent NMOSD can manifest with optic neuritis and transverse myelitis. AQP-4 antibody positivity confirms the diagnosis. Prompt treatment is critical to manage the acute symptoms and prevent relapses, as highlighted by a young patient's case with optic neuritis and extensive spinal cord lesions. Abstract: Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disorder of the central nervous system that affects the optic nerve and spinal cord. It is associated with autoantibodies against aquaporin-4 (AQP-4) and/or myelin oligodendrocytes glycoproteins. It is diagnosed based on clinical, radiological, and serological criteria, and treated with immunosuppressants in the acute phase. Long-term immunosuppression is essential to prevent potential relapses. In this case report, we present the case of a 19-year-old female patient with systemic lupus erythematosus (SLE), who presented with blurriness and loss of vision in her left eye. Optical coherence tomography was normal, but a gadolinium-enhanced cervico-dorsal MRI showed multiple lesions extending from the brainstem to the C7-T1 junction suggestive of longitudinally extensive transverse myelitis (LETM), the largest of which was a cystic lesion at the cervico-spinal junction. A contrast injection also revealed left optic neuritis. Cerebrospinal fluid analysis showed elevated IgG and red blood cell count, but no oligoclonal bands. The patient tested positive for AQP-4 autoantibodies, confirming the diagnosis of NMOSD. Treatment with intravenous methylprednisolone led to partial improvement, but the patient experienced a relapse with severe neurological symptoms, including tetraplegia and bladder and bowel dysfunction. This case illustrates the importance of considering NMOSD in the differential diagnosis of patients with SLE who present with optic neuritis and/or myelitis, especially when MRI findings are suggestive of LETM. Early diagnosis and adherence to treatment are crucial to prevent further relapses and deleterious sequelae.

Rational structure-guided design of a blood stage malaria vaccine immunogen presenting a single epitope from PfRH5.

There is an urgent need for improved malaria vaccine immunogens. Invasion of erythrocytes by Plasmodium falciparum is essential for its life cycle, preceding symptoms of disease and parasite transmission. Antibodies which target PfRH5 are highly effective at preventing erythrocyte invasion and the most potent growth-inhibitory antibodies bind a single epitope. Here we use structure-guided approaches to design a small synthetic immunogen, RH5-34EM which recapitulates this epitope. Structural biology and biophysics demonstrate that RH5-34EM is correctly folded and binds neutralising monoclonal antibodies with nanomolar affinity. In immunised rats, RH5-34EM induces PfRH5-targeting antibodies that inhibit parasite growth. While PfRH5-specific antibodies were induced at a lower concentration by RH5-34EM than by PfRH5, RH5-34EM induced antibodies that were a thousand-fold more growth-inhibitory as a factor of PfRH5-specific antibody concentration. Finally, we show that priming with RH5-34EM and boosting with PfRH5 achieves the best balance between antibody quality and quantity and induces the most effective growth-inhibitory response. This rationally designed vaccine immunogen is now available for use as part of future malaria vaccines, alone or in combination with other immunogens.

Peripheral facial palsy in children: Serum Borrelia antibodies may reduce the need for lumbar puncture.

AIM: We aimed to investigate the causes of acute peripheral facial palsy (PFP) in Danish children and to explore whether neuroborreliosis-related PFP could be diagnosed without lumbar puncture using clinical symptoms and serum Borrelia burgdorferi (Bb) antibodies. METHODS: This retrospective population-based cohort study included children undergoing lumbar puncture for PFP between 2019 and 2023 in Denmark's Capital Region. Diagnostic performance measures for neuroborreliosis-related PFP were compared between serum Bb IgG alone and clinical risk scores combining Bb IgG with clinical parameters. RESULTS: Of the 326 patients with PFP, 137 (42%) were diagnosed with neuroborreliosis and 151 (46%) had Bell's palsy. Positive predictive value for serum Bb IgG alone was 88% (95% CI 79-93) and negative predictive value was 83% (95% CI 75-88). The positive predictive value of a risk score with seven additional parameters was 90% (95% CI 81-95) and negative predictive value 87% (95% CI 80-92). CONCLUSION: The positive predictive value of serum Bb IgG alone was high in our setting, where nearly half of children with PFP had neuroborreliosis. In high endemic settings, lumbar punctures may be reduced by (i) treating all children with PFP with doxycycline or (ii) treating Bb IgG positive children and performing lumbar puncture in seronegative children.

Next-Generation Therapeutic Antibodies for Cancer Treatment: Advancements, Applications, and Challenges.

The field of cancer treatment has evolved significantly over the last decade with the emergence of next-generation therapeutic antibodies. Conventional treatments like chemotherapy pose significant challenges, including adverse side effects. Monoclonal antibodies have paved the way for more targeted and effective interventions. The evolution from chimeric to humanized and fully human antibodies has led to a reduction in immunogenicity and enhanced tolerance in vivo. The advent of next-generation antibodies, including bispecific antibodies, nanobodies, antibody-drug conjugates, glyco-engineered antibodies, and antibody fragments, represents a leap forward in cancer therapy. These innovations offer increased potency, adaptability, and reduced drug resistance. Challenges such as target validation, immunogenicity, and high production costs exist. However, technological advancements in antibody engineering techniques provide optimism for addressing these issues. The future promises a paradigm shift, where ongoing research will propel these powerful antibodies to the forefront, revolutionizing the fight against cancer and creating new preventive and curative treatments. This review provides an overview of three next-generation antibody-based molecules, namely bispecific antibodies, antibody-drug conjugates, and nanobodies that have shown promising results in cancer treatment. It discusses the evolution of antibodies from conventional forms to next-generation molecules, along with their applications in cancer treatment, production methods, and associated challenges. The review aims to offer researchers insights into the evolving landscape of next-generation antibody-based cancer therapeutics and their potential to revolutionize treatment strategies.

Anti-sulfatide antibodies in neurological disorders: should we test?

OBJECTIVE: Neurological autoimmune peripheral and central nervous system disorders can be associated with anti-sulfatide antibodies. These antibodies are considered potential diagnostic biomarkers, although their additional diagnostic value in neurological fields has been increasingly questioned. Given the little evidence of anti-sulfatide antibodies' frequency and diagnostic value in neurology, we aimed to fill this knowledge gap by investigating 10 years of data. METHODS: This retrospective study analyzed the results of the anti-ganglioside dot kits (GA Generic Assays GmbH) from 1318 serum samples and 462 cerebrospinal fluid (CSF) samples for the frequency, sensitivity, and specificity of anti-sulfatide antibodies in neurological disorders. RESULTS: Although anti-sulfatide antibodies are rarely present in neurological autoimmune disorders (serum IgM 2.5%, IgG 4.6%), they are also present in non-autoimmune diseases (serum IgM 1.2%, IgG 2.5%) and lack sensitivity and specificity towards being a diagnostic marker. Furthermore, anti-sulfatide antibodies are rarely found in CSF (e.g., no positive results for IgM), and including so-called borderline results ((+)) increases sensitivity and the false-positive rate in serum and CSF. DISCUSSION: While anti-sulfatide antibodies appear more frequently in neurological autoimmune diseases, they are rare overall and provide very limited diagnostic value in determining specific neurological diseases and-more importantly-if a neurological disease has a potential autoimmune etiology.

Matching-adjusted indirect comparison of talquetamab vs selinexor-dexamethasone and vs belantamab mafodotin in patients with relapsed/refractory multiple myeloma.

OBJECTIVE: Talquetamab is the first GPRC5D-targeting bispecific antibody approved for the treatment of triple-class exposed (TCE) relapsed/refractory multiple myeloma (RRMM). This matching-adjusted indirect comparison (MAIC) study was conducted to compare the effectiveness of talquetamab vs selinexor-dexamethasone (sel-dex) and vs belantamab mafodotin (belamaf) in patients with TCE RRMM. METHODS: An unanchored MAIC was performed using individual patient-level data from patients treated with subcutaneous talquetamab 0.4 mg/kg weekly (QW) and 0.8 mg/kg every other week (Q2W) from MonumenTAL-1 (NCT03399799/NCT04636552) and published summary data for sel-dex from STORM (NCT02336815) and belamaf from DREAMM-2 (NCT0325678). Patients from MonumenTAL-1 who met key eligibility criteria for STORM and DREAMM-2 were included. Outcomes of interest were overall response rate (ORR), complete response or better (≥CR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS). RESULTS: After adjustment for cross-trial differences, patients treated with both dosing schedules of talquetamab showed significantly better ORR, ≥CR, and DOR vs sel-dex and significantly higher ORR and ≥ CR vs belamaf; DOR was relatively similar to belamaf. PFS was significantly improved with talquetamab Q2W and numerically in favor of talquetamab QW vs sel-dex and significantly improved with both dosing schedules of talquetamab vs belamaf. OS was significantly improved with both dosing schedules of talquetamab vs sel-dex and was numerically in favor of both dosing schedules of talquetamab vs belamaf. CONCLUSION: These analyses show superior effectiveness of both talquetamab dosing schedules vs sel-dex and vs belamaf for most outcomes and highlight talquetamab as an effective treatment option for patients with TCE RRMM.

Immune correlates analysis of the Imbokodo (HVTN 705/HPX2008) efficacy trial of a mosaic HIV-1 vaccine regimen evaluated in Southern African people assigned female sex at birth: a two-phase case-control study.

BACKGROUND: The HVTN 705 Imbokodo trial of 2636 people without HIV and assigned female sex at birth, conducted in southern Africa, evaluated a heterologous HIV-1 vaccine regimen: mosaic adenovirus 26-based vaccine (Ad26.Mos4.HIV) at Months 0, 3, 6, 12 and alum-adjuvanted clade C gp140 at Months 6, 12. Per-protocol vaccine efficacy (VE) against HIV-1 diagnosis from seven to 24 months was 14.1% (95% CI: -22.0% to 39.5%). Immune correlates analysis was performed for markers selected based on prior evidence in efficacy trials and/or nonhuman primate models. METHODS: Humoral and cellular immune response markers at Month 7 were evaluated as immune correlates of risk and of protection in a breakthrough case-control cohort (n = 52 cases, 246 non-cases). Primary markers were IgG binding to vaccine-strain gp140, IgG3 binding to diverse Env antigens (IgG3 Env breadth), IgG3 binding to diverse V1V2 antigens (IgG3 V1V2 breadth), antibody-dependent phagocytosis against the vaccine-strain gp140, Env-specific CD4+ and CD8+ T-cell responses, and multi-epitope functions. FINDINGS: No immune markers were statistically significant correlates of risk. IgG3 V1V2 breadth trended toward an inverse association: hazard ratio 0.70 (95% CI: 0.36 to 1.35; p = 0.29) per 10-fold increase and 0.51 (95% CI: 0.21 to 1.24; p = 0.14) in a Cox model with all primary markers. The VE estimate was 11.8% (95% CI: -17.9% to 34.0%) at all IgG3 V1V2 breadth values below 667 weighted geometric mean net MFI; just above this value, the VE estimate sharply increased to 62.6% (95% CI: -17.9% to 89.6%), and further increased to 80.9% (95% CI: -17.9% to 99.5%) at 1471 MFI, the 95th percentile of the marker distribution. Mediation analysis yielded a VE of 35.7% (95% CI: 15.0% to 51.3%) attributable to the vaccine's impact on this marker. INTERPRETATION: The trend in association of greater IgG3 V1V2 antibody breadth with lower likelihood of HIV acquisition is consistent with the identification of antibodies against V1V2 as immune correlates in three other HIV vaccine efficacy trials and suggests that a greater emphasis should be placed on studying this region in the HIV-1 envelope as a vaccine immunogen. FUNDING: National Institute of Allergy and Infectious Diseases and Janssen Vaccines & Prevention BV.

Denovo glomerulonephritis associated with IgA anti-GBM alloantibodies after kidney transplantation in Alport syndrome: A case report with diagnostic implications.

Alport syndrome (AS) is a hereditary disorder caused by pathogenic variants in COL4A3, COL4A4, or COL4A5 genes expressing α3, α4, and α5 chains of basement membrane type IV collagen (COL4). The triple-helical α3α4α5(IV) protomer is a major component of the mature glomerular basement membrane (GBM) whose defective formation in AS leads to structural GBM disruption and kidney dysfunction, often resulting in kidney replacement therapy. A genetically intact renal graft exposes the immune system to a non-tolerized α3α4α5(IV) component and an alloimmune response eventually ensues. So far, only IgG alloantibodies reacting against COL4 have been reported in AS alloimmune responses. Here, we report alloimmune glomerulonephritis mediated by IgA antibodies against the non-collagenous C-terminal domain 1 of the α5(IV) chain in a patient with autosomal recessive AS following a second kidney transplantation. The patient presented a not previously described biallelic variant in the COL4A4 gene. Immunological, diagnostic, and clinical implications are discussed.

Efficient α and ß- radionuclide therapy targeting fibroblast activation protein-α in an aggressive preclinical mouse tumour model.

PURPOSE: Targeted radionuclide therapy (TRT) is a cancer treatment with relative therapeutic efficacy across various cancer types. We studied the therapeutic potential of TRT using fibroblast activation protein-α (FAP) targeting sdAbs (4AH29) labelled with 225Ac or 131I in immunocompetent mice in a human FAP (hFAP) expressing lung cancer mouse model. We further explored the combination of TRT with programmed cell death ligand 1 (PD-L1) immune checkpoint blockade (ICB). METHODS: We studied the biodistribution and tumour uptake of [131I]I-GMIB-4AH29 and [225Ac]Ac-DOTA-4AH29 by ex vivo γ-counting. Therapeutic efficacy of [131I]I-GMIB-4AH29 and [225Ac]Ac-DOTA-4AH29 was evaluated in an immunocompetent mouse model. Flow cytometry analysis of tumours from [225Ac]Ac-DOTA-4AH29 treated mice was performed. Treatment with [225Ac]Ac-DOTA-4AH29 was repeated in combination with PD-L1 ICB. RESULTS: The biodistribution showed high tumour uptake of [131I]I-GMIB-4AH29 with 3.5 ± 0.5% IA/g 1 h post-injection (p.i.) decreasing to 0.9 ± 0.1% IA/g after 24 h. Tumour uptake of [225Ac]Ac-DOTA-4AH29 was also relevant with 2.1 ± 0.5% IA/g 1 h p.i. with a less steep decrease to 1.7 ± 0.2% IA/g after 24 h. Survival was significantly improved after treatment with low and high doses [131I]I-GMIB-4AH29 or [225Ac]Ac-DOTA-4AH29 compared to vehicle solution. Moreover, we observed significantly higher PD-L1 expression in tumours of mice treated with [225Ac]Ac-DOTA-4AH29 compared to vehicle solution. Therefore, we combined high dose [225Ac]Ac-DOTA-4AH29 with PD-L1 ICB showing therapeutic synergy. CONCLUSION: [225Ac]Ac-DOTA-4AH29 and [131I]I-GMIB-4AH29 exhibit high and persistent tumour targeting, translating into prolonged survival in mice bearing aggressive tumours. Moreover, we demonstrate that the combination of PD-L1 ICB with [225Ac]Ac-DOTA-4AH29 TRT enhances its therapeutic efficacy.

Efficacy of Anti-Thyroid Medications in Patients with Graves' Disease.

INTRODUCTION: Graves' disease (GD) is an autoimmune disorder characterized by hyperthyroidism due to increased thyroid-stimulating hormone receptor antibodies (TRAb).The treatment of GD often consists of radioactive iodine therapy, anti-thyroid drugs (ATD), or thyroidectomy. Since few studies have collected data on remission rates after treatment with ATD in Saudi Arabia, our study aimed to assess the efficacy and the clinical predictors of GD long-term remission with ATD use. METHOD: We conducted a retrospective chart review study of 189 patients with GD treated with ATD between July 2015 and December 2022 at the endocrine clinics in King Abdulaziz Medical City in Riyadh. All GD patients, adults, and adolescents aged 14 years and older who were treated with ATD during the study period and had at least 18 months of follow-up were included in the study. Patients with insufficient follow-up and those who underwent radioactive iodine (RAI) therapy or thyroidectomy as first-line therapy for GD were excluded from the study. RESULTS: The study sample consisted of 189 patients, 72% of whom were female. The patients' median age was 38years (33, 49). A total of 103 patients (54.5%) achieved remission. The median follow-up period for the patients was 22.0 months (9, 36). Patients who achieved remission had lower mean free T4 levels (25.8pmol/l ± 8.93 versus 28.8pmol/l ± 10.82) (P value = 0.038) and lower median TRAb titer (5.1IU/l (2.9, 10.7)) versus (10.5IU/l (4.2, 22.5)) (P value = 0.001) than patients who did not achieve remission. Thirty-five out of 103 patients who achieved remission (34%) relapsed after ATD discontinuation. The patients who relapsed showed higher median thyroid uptake on 99mTc-pertechnetate scan than patients who did not relapse: 10.3% (5.19, 16.81) versus 6.0% (3.09, 12.38), with a P value of 0.03. They also received ATD for a longer period, 40.0 months (29.00, 58.00) versus 25.0 months (19.00, 32.50), with a P value of < 0.0001. CONCLUSION: The remission of GD was achieved in approximately half of the patients treated with ATD; however, approximately one-third of them relapsed. Lower Free T4 and TRAb levels at diagnosis were associated with remission. Longer ATD use and higher thyroid uptake upon diagnosis were associated with relapse after ATD discontinuation. Future studies are necessary to ascertain the predictors of ATD success in patients with GD.

Dynamics and implications of anti-drug antibodies against adalimumab using ultra-sensitive and highly drug-tolerant assays.

Background: Adalimumab induces the production of anti-drug antibodies (ADA) that may lead to reduced drug concentration and loss-of-response, posing significant clinical challenges. However, traditional immunoassays have limitations in terms of sensitivity and drug-tolerance, hindering the insights of ADA response. Methods: Herein, we developed an integrated immunoassay platform combining the electrochemiluminescence immunoassay with immunomagnetic separation strategy. A longitudinal cohort study involving 49 patients with ankylosing spondylitis was carried out to analyze the dynamic profiles of ADA and to investigate the impact of ADA on adalimumab pharmacokinetics using a population pharmacokinetic model. Additionally, cross-sectional data from 12 patients were collected to validate the correlation between ADA levels and disease relapse. Results: The ADA assay demonstrated high sensitivity (0.4 ng/mL) and drug-tolerance (100 µg/mL), while the neutralizing antibodies (NAB) assay showed a sensitivity of 100 ng/mL and drug-tolerance of 20 µg/mL. Analysis of the longitudinal cohort revealed that a majority of patients (44/49, 90%) developed persistent ADA within the first 24 weeks of treatment. ADA levels tended to plateau over time after an initial increase during the early immune response phase. Further, nearly all of the tested patients (26/27, 96%) were classified as NAB positive, with a strong correlation between ADA levels and neutralization capacity (R2 = 0.83, P < 0.001). Population pharmacokinetic modeling revealed a significant positive association between model-estimated individual clearance and observed ADA levels. Higher ADA levels were associated with adalimumab clearance and disease relapse in a cross-sectional cohort, suggesting a promising ADA threshold of 10 for potential clinical application. Moreover, the IgG class was the primary contributor to ADA against adalimumab and the apparent affinity exhibited an increasing trend over time, indicating a T-cell dependent mechanism for ADA elicitation by adalimumab. Conclusion: In summary, this integrated immunoassay platform shows promise for in-depth analysis of ADA against biologics, offering fresh insights into immunogenicity and its clinical implications.

Anti-Smith Antibodies as a Predictive Factor for Developing Lupus Nephritis in Systemic Lupus Erythematosus Patients: A Systematic Review.

Lupus nephritis (LN) is the most frequent and lethal complication of systemic lupus erythematosus (SLE), often presenting with subtle or no initial symptoms. Therefore, it is crucial to identify SLE patients who are at risk of developing LN to ensure they receive timely intervention. Significant scientific efforts have been made to identify various genes and antibodies that could increase the risk of LN. Our objective is to review the role of anti-Smith antibodies in this disease and evaluate their potential as a predictive marker for LN. This review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We searched for different study types from 2019 onwards as per our inclusion and exclusion criteria, to look for the significance of anti-Smith antibodies. The following databases were used: PubMed, PMC, Google Scholar, Science Direct, and Scopus. Twenty-two studies were checked for eligibility, of which 17 studies passed, based on the commonly used quality assessment tool for each of the corresponding studies. The study results indicated that anti-Smith antibodies are highly specific for SLE and are part of its classification criteria. In addition, we observed that positive titers correlate with disease activity. The presence of anti-Smith antibodies is influenced by ethnicity being most common among Black patients. However, the data regarding their effectiveness as a predictive marker for LN is not fully established. A more sensitive investigation and larger cohorts on diverse ethnic populations could provide a definitive answer regarding the role of anti-Smith antibodies in LN, highlighting the need for additional research.

Short CDRL1 in intermediate VRC01-like mAbs is not sufficient to overcome key glycan barriers on HIV-1 Env.

VRC01-class broadly neutralizing antibodies (bnAbs) have been isolated from people with HIV-1, but they have not yet been elicited by vaccination. They are extensively somatically mutated and sometimes accumulate CDRL1 deletions. Such indels may allow VRC01-class antibodies to accommodate the glycans expressed on a conserved N276 N-linked glycosylation site in loop D of the gp120 subunit. These glycans constitute a major obstacle in the development of VRC01-class antibodies, as unmutated antibody forms are unable to accommodate them. Although immunizations of knock-in mice expressing human VRC01-class B-cell receptors (BCRs) with specifically designed Env-derived immunogens lead to the accumulation of somatic mutations in VRC01-class BCRs, CDRL1 deletions are rarely observed, and the elicited antibodies display narrow neutralizing activities. The lack of broad neutralizing potential could be due to the absence of deletions, the lack of appropriate somatic mutations, or both. To address this point, we modified our previously determined prime-boost immunization with a germline-targeting immunogen nanoparticle (426c.Mod.Core), followed by a heterologous core nanoparticle (HxB2.WT.Core), by adding a final boost with a cocktail of various stabilized soluble Env trimers. We isolated VRC01-like antibodies with extensive somatic mutations and, in one case, a seven-amino acid CDRL1 deletion. We generated chimeric antibodies that combine the vaccine-elicited somatic mutations with CDRL1 deletions present in human mature VRC01 bnAbs. We observed that CDRL1 indels did not improve the neutralizing antibody activities. Our study indicates that CDRL1 length by itself is not sufficient for the broadly neutralizing phenotype of this class of antibodies. IMPORTANCE: HIV-1 broadly neutralizing antibodies will be a key component of an effective HIV-1 vaccine, as they prevent viral acquisition. Over the past decade, numerous broadly neutralizing antibodies (bnAbs) have been isolated from people with HIV. Despite an in-depth knowledge of their structures, epitopes, ontogenies, and, in a few rare cases, their maturation pathways during infection, bnAbs have, so far, not been elicited by vaccination. This necessitates the identification of key obstacles that prevent their elicitation by immunization and overcoming them. Here we examined whether CDRL1 shortening is a prerequisite for the broadly neutralizing potential of VRC01-class bnAbs, which bind within the CD4 receptor binding site of Env. Our findings indicate that CDRL1 shortening by itself is important but not sufficient for the acquisition of neutralization breadth, and suggest that particular combinations of amino acid mutations, not elicited so far by vaccination, are most likely required for the development of such a feature.

A monoclonal antibody targeting the Nipah virus fusion glycoprotein apex imparts protection from disease.

Nipah virus (NiV) is a highly pathogenic paramyxovirus capable of causing severe respiratory and neurologic disease in humans. Currently, there are no licensed vaccines or therapeutics against NiV, underscoring the urgent need for the development of countermeasures. The NiV surface-displayed glycoproteins, NiV-G and NiV-F, mediate host cell attachment and fusion, respectively, and are heavily targeted by host antibodies. Here, we describe a vaccination-derived neutralizing monoclonal antibody, mAb92, that targets NiV-F. Structural characterization of the Fab region bound to NiV-F (NiV-F-Fab92) by cryo-electron microscopy analysis reveals an epitope in the DIII domain at the membrane distal apex of NiV-F, an established site of vulnerability on the NiV surface. Further, prophylactic treatment of hamsters with mAb92 offered complete protection from NiV disease, demonstrating beneficial activity of mAb92 in vivo. This work provides support for targeting NiV-F in the development of vaccines and therapeutics against NiV.IMPORTANCENipah virus (NiV) is a highly lethal henipavirus (HNV) that causes severe respiratory and neurologic disease in humans. Currently, there are no licensed vaccines or therapeutics against NiV, highlighting a need to develop countermeasures. The NiV surface displays the receptor binding protein (NiV-G, or RBP) and the fusion protein (NiV-F), which allow the virus to attach and enter cells. These proteins can be targeted by vaccines and antibodies to prevent disease. This work describes a neutralizing antibody (mAb92) that targets NiV-F. Structural characterization by cryo-electron microscopy analysis reveals where the antibody binds to NiV-F to neutralize the virus. This study also shows that prophylactic treatment of hamsters with mAb92 completely protected against developing NiV disease. This work shows how targeting NiV-F can be useful to preventing NiV disease, supporting future studies in the development of vaccines and therapeutics.

Effects of Bushen Huoxue on integrin ß3 and integrin ß5 in the placental tissue of mice with repeated implantation failure caused by phospholipid antibodies.

BACKGROUND: This study aimed to investigate the effects of the Kidney-Tonifying and Blood-Activating Formula on combating the downregulation of integrin ß3 and integrin ß5 in mouse placental tissue induced by phospholipid antibodies. OBJECTIVE: This study aimed to investigate the effects of kidney-tonifying and blood-activating formulations on combating the downregulation of integrin ß3 and integrin ß5 in mouse placental tissue induced by phospholipid antibodies. METHODS: Mice in the phospholipid antibody group and phospholipid antibody + kidney-tonifying and blood-activating formula group underwent repeated implantation experiments, and the expression of integrin ß3 and integrin ß5 in placental tissue was observed. The effects of the kidney-tonifying and blood-activating formula on mouse placental tissue were evaluated through biochemical index tests, histopathological observations, and immunohistochemical staining. RESULTS: After intervention with the kidney-tonifying and blood-activating formula, the expression of integrin ß3 and integrin ß5 in placental tissue was notably upregulated, and placental structure was restored. Kidney-Tonifying and Blood-Activating Formula significantly improved abnormal biochemical indices and exerted a remarkable protective effect on placental tissue pathology. CONCLUSION: The kidney-tonifying and blood-activating formula effectively counteracted the downregulation of integrin ß3 and integrin ß5 in mouse placental tissue induced by phospholipid antibodies and alleviated placental tissue pathology through structural improvement and protection. Therefore, kidney-tonifying and blood-activating formulas may serve as potential therapeutic agents for recurrent implantation failure, offering new insights and approaches for clinical treatment.

The impact of donor-specific antibodies' presence on the outcome post-allogeneic hematopoietic stem cell transplantation: a survey from a single center.

Introduction: Donor-specific antibodies (DSAs) correspond to anti-HLA antibodies of the recipient that are specifically directed to a mismatched antigen of the donor. In the setting of solid organ transplantation DSAs are associated with rejection. Their role is still debated in allogeneic cell transplantation. International guidelines recommend testing patients for DSA before transplant, and if possible, choosing a donor with negative screening. Methods: We collected clinical data of 236 recipients of alloSCT, performed at our institution from March 2019 to October 2023, to evaluate their impact on engraftment. Serum from all patients was tested for DSA. Results: 186 patients (79%) achieved sustained myeloid engraftment within day 30 post alloSCT. Thirty-two out 236 (13%) patients engrafted after day 30 post alloSCT. The median times to neutrophil engraftment and platelet engraftment were respectively 21 days (range 11-121 days) and 19 days (range 10-203 days). Fourteen out 236 patients (6%) experienced PrGF. .Twenty-nine patients (12 %) were DSA-positive. Among 29 patients with DSA positivity, 17 had a haploidentical donor and 12 had a UD donor. DSA positivity directly correlates respectively with neutrophil and platelets engraftment failure at 30 days after alloSCT (p=0.01 and p= 0.0004). Univariate Cox analysis showed that factors, including DSAs positivity, disease type, disease status, donor type, conditioning regimen, patient's age, and CD34+ were correlated with neutrophil and platelet engraftment failure at 30 days after alloSCT. Younger patients with DSA negativity, with acute leukemia, in complete response at the time of transplant, who received a higher dose of CD34+ cells from a sibling donor after a myeloablative conditioning regimen, have a reduced risk of neutrophil and platelet engraftment failure at day +30 post alloSCT.Multivariate analysis confirmed the impact of the presence of DSA only for platelet engraftment, confirming the role of type and status disease, donor type, recipient age, and CD34+ cells infused on engraftment. DSA presence has no impact on TRM, DFS, and OS. Discussion: PrGF has a multifactorial pathogenesis, where DSA is not the only player, but its impact could vary depending on the transplant platform. Thus patient screening may be helpful to choose the best donor and transplant strategy.

An immunoassay based on bioluminescent sensors for rapid detection of African swine fever virus antibodies.

Serological assays for antibody detection have contributed significantly to the diagnosis and control of infectious diseases. African swine fever is the most devastating infectious disease of domestic pigs and wild boars, severely threatening the global pig industry in recent years. Here, we developed a rapid, simple, and sensitive immunoassay based on the split-luciferase system to detect IgG antibodies against African swine fever virus (ASFV). In this assay, the p30 protein of ASFV was genetically coupled to the LgBiT and SmBiT subunits of nanoluciferase, which were used as fusion probes for specific antibodies. Target engagement of the probes results in the reconstitution of a functional nanoluciferase, which further catalyzes bioluminescent reactions. Different orientations of the LgBiT and SmBiT-p30 fusion sensors were designed and investigated, and N-LgBiT/p30 and N-SmBiT/p30 were identified as a promising sensor pair for reforming active nanoluciferase in the presence of specific antibodies. After optimization, this split-luciferase complementation assay showed high sensitivity and specificity for the detection of ASFV antibodies. The analytical sensitivity of the assay was 16 times greater than that of the blocking enzyme-linked immunosorbent assay (ELISA) by the detection of serial dilutions of serum, and no cross-reaction was observed with other swine pathogens. As demonstrated in clinical samples, its performance is highly consistent with that of a commercial ELISA kit, with a concordance rate of 98.19%. This assay is simple and easy to perform, providing a more flexible and efficient approach for the measurement of ASFV antibodies in clinical applications. IMPORTANCE: The study is about a homogeneous split-luciferase assay for antibody detection. Split nanoluciferase biosensors for the detection of ASFV antibodies were designed. This sensor platform enables the sensitive and specific detection of antibodies. The split-luciferase assay is simple, rapid, and easy to use.