Antibodies最新文献

Background: Podocalyxin (PODXL) has been identified as a promising therapeutic target and a potential diagnostic biomarker in various tumors. Despite the therapeutic potential of anti-PODXL monoclonal antibodies (mAbs), their further development has been limited by concerns regarding potential on-target off-tumor toxicities. To minimize adverse effects on normal tissues, developing a cancer-specific mAb (CasMab) against PODXL is essential. Methods: Our group established a cancer-specific anti-PODXL mAb, PcMab-60 (IgM, κ), through the screening of over one hundred hybridoma clones. In this study, PcMab-60 was engineered into a humanized IgG₁-type mAb (humPcMab-60), and its antitumor activity was examined using mouse xenograft models of pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer. Results: HumPcMab-60 retains cancer-specific reactivity; humPcMab-60 reacted to PDAC cell lines (PK-45H and MIA PaCa-2) and the colorectal cancer cell line (Caco-2), but not to a normal lymphatic endothelial cell line in flow cytometry. Furthermore, humPcMab-60 exerted antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity against PODXL-expressing cell lines and showed antitumor effects against the tumor xenografts. Conclusions: A humanized anti-PODXL CasMab, humPcMab-60, could be a promising mAb-based tumor therapy.

Background/Objectives: Anti-p200 pemphigoid is a rare and likely underdiagnosed autoimmune blistering disorder. Laminin γ1 and laminin β4 have been implicated as potential target antigens in its pathogenesis. Recently, a novel indirect immunofluorescence assay targeting anti-laminin β4 antibodies has been developed, demonstrating high sensitivity and specificity, and offering a valuable tool for improved diagnosis. Methods: Of the 451 patients, 21 were selected for further laboratory analysis based on medical records. Sera from 10 patients, which showed a positive direct immunofluorescence (DIF) result and negative results in multiplex enzyme-linked immunosorbent assays (ELISAs) and/or mosaic six-parameter indirect immunofluorescence (IIF) for various autoimmune bullous diseases, were tested for the presence of anti-laminin β4 antibodies. Additionally, sera from 11 patients with positive DIF and positive ELISA for antibodies against BP180 and/or BP230 were analyzed. Results: Among the 10 patients with positive DIF and negative ELISA and/or mosaic six-parameter IIF, 6 sera were positive for anti-laminin β4 antibodies. These patients presented with atypical clinical features. In contrast, all 11 sera from patients with both positive DIF and positive ELISA for BP180 and/or BP230 were negative for anti-laminin β4 antibodies. Conclusions: In patients with a positive DIF result but negative ELISA and/or mosaic six-parameter IIF findings, testing for anti-laminin β4 antibodies should be considered. Furthermore, in cases presenting with atypical clinical features-such as acral distribution of lesions, intense pruritus, or erythematous-edematous plaques-the possibility of anti-p200 pemphigoid should be included in the differential diagnosis.

Antibody-mediated autoimmune diseases are common, can involve any organ system, and pose a large burden for patients and healthcare systems. Most antibody-mediated diseases are mediated by IgG antibodies. Selective targeting of pathogenic antibodies is an attractive treatment option which has already proven to be effective in antibody-positive generalized myasthenia gravis, maternal-fetal alloimmune cytopenias, and immune thrombocytopenic purpura. Warm autoimmune hemolytic anemia (wAIHA) is an autoimmune disorder mediated by pathogenic antibodies mainly of the IgG class with no approved therapy. Current treatment includes non-specific immunosuppression with corticosteroids, rituximab, and other immunosuppressive agents. With most therapies, time to response can be delayed and transfusions may be needed. Neonatal Fc receptor (FcRN) therapies provide rapid and sustained reduction of pathogenic IgG levels providing potential for fast, effective therapy in antibody-mediated autoimmune diseases including warm autoimmune hemolytic anemia. This review focuses on the emerging role of FcRn inhibition in autoimmune hematologic diseases, and their therapeutic potential in wAIHA.

Pompe disease is a rare autosomal-recessive neuromuscular disorder caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA), leading to the pathological accumulation of glycogen and impaired autophagy. Enzyme replacement therapy (ERT) with recombinant human alpha-glucosidase (rhGAA) has been available since 2006, but may lead to the formation of anti-drug antibodies (ADAs) against the recombinant human enzyme, which, in turn, may adversely affect the response to ERT. Knowledge of the antigenic determinants of rhGAA involved in interaction with ADAs may facilitate the development of strategies to attenuate the anti-drug immune response in patients. Here, we determined the rhGAA ADA epitopes in the plasma of Pompe disease patients using a series of affinity purifications combined with epitope extraction and label free quantitation LC-MS.

Background/objectives: Immune-mediated necrotizing myopathy (IMNM) is a severe inflammatory myopathy marked by proximal muscle weakness, elevated creatine kinase (CK), and the presence of anti-HMGCR antibodies. Statin exposure is a recognized trigger for anti-HMGCR-positive IMNM, which may persist despite statin withdrawal. This pilot case series explores, for the first time, the use of bempedoic acid-a liver-specific lipid-lowering agent with minimal muscle toxicity-as an alternative to statins in these patients.

Methods: We report 10 anti-HMGCR-antibody-positive IMNM patients (6 females, 4 males) previously on statins for primary prevention (8 on atorvastatin, 2 on simvastatin) without prior cardiovascular events. Statins were discontinued at myositis onset. All patients received prednisone and immunosuppressants (methotrexate in 7, mycophenolate in 3), plus bempedoic acid. Anti-HMGCR antibodies were measured using a chemiluminescence method.

Results: Their mean anti-HMGCR antibody levels decreased significantly from 390.93 ± 275.22 to 220.89 ± 113.37 CU/L (p = 0.027) after 6 months of treatment. Their CK levels dropped from 1278.9 ± 769.39 to 315.1 ± 157.72 IU/L (p = 0.001), and aldolase dropped from 11.63 ± 2.18 to 6.61 ± 1.22 U/L (p = 0.0001). The mean LDL-C value was 96.1 ± 8.16 mg/dL. No disease recurrence was observed. Autoimmune panels were negative for other myositis-associated and/or -specific antibodies.

Conclusions: Bempedoic acid appears to be a safe, effective, and cost-efficient lipid-lowering alternative in statin-intolerant IMNM patients. Larger studies are warranted to confirm its efficacy across different subgroups and to optimize dyslipidemia management in this setting.

Background: Mepolizumab is an effective treatment for severe eosinophilic asthma, leading to a depletion of blood eosinophil levels, the clinical relevance of which remains unclear. Objective: The aim of this study was to assess the relationship between mepolizumab-induced blood eosinophil reduction and clinical outcome in patients with severe eosinophilic asthma, in particular, whether the magnitude of blood eosinophil reduction was associated with clinical remission. Methods: We conducted a real-world retrospective analysis of 58 adult patients with severe eosinophilic asthma treated with mepolizumab. Clinical and respiratory functional parameters were evaluated at the start of mepolizumab treatment (T0) and after two years of treatment (T2; mean follow-up: 22.8 ± 7.5 months). Blood eosinophil counts were recorded at T0 and during the first year of treatment (T1; mean follow-up: 7.7 ± 4.1 months). Results: After two years of mepolizumab treatment, 58 severe asthmatic patients showed significant improvements in ACT score, FVC, and FEV₁ and a reduction in acute exacerbations and the use of maintenance therapies. Clinical remission was achieved in 55.1% of patients. Lower blood eosinophil counts during the first year (T1) were associated with greater improvements in lung function and fewer exacerbations. A greater relative decrease in eosinophils from baseline to T1 (ΔEOS%) was significantly associated with remission, reductions in exacerbations, and no maintenance OCS use. ΔEOS% was the only independent predictor of remission in the multivariate analysis. A ≥90% reduction predicted remission with 80% specificity (AUC = 0.726). Conclusions: Monitoring blood eosinophils after mepolizumab initiation could be a useful tool for predicting long-term response to treatment. In particular, a reduction by over 90% of peripheral blood eosinophils during the first year of mepolizumab treatment predicts clinical remission with a specificity of 80%. Considering the accessibility and the low cost of this biomarker, it may help to optimize long-term asthma management.

Background/objectives: Anti-drug antibody (ADA) formation can impact the safety, pharmacokinetics, and/or efficacy of biotherapeutics, including monoclonal antibodies (mAbs). Current strategies for ADA/immunogenicity risk prediction of mAbs include in silico algorithms, T cell proliferation assays, MHC-associated peptide proteomics assays (MAPPs), and dendritic cell internalization assays. However, B cell-mediated responses are not assessed in these assays. B cells are professional antigen-presenting cells (APCs) and secrete antibodies toward immunogenic mAbs. Therefore, methods to determine B cell responses would be beneficial for immunogenicity risk prediction and may provide a more comprehensive assessment of risk.

Methods: We used a PBMC culture method with the addition of IL-4, IL-21, B cell activating factor (BAFF), and an anti-CD40 agonist mAb to support B cell survival and activation.

Results: B cells in this assay format become activated, proliferate, and secrete IgG. A panel of 51 antibodies with varying clinical immunogenicity rates were screened in this assay with IgG secretion used as a readout for immunogenicity risk. IgG secretion differed among test articles but did not correlate with the clinical immunogenicity rating.

Conclusions: This dataset highlights the challenges of developing a B cell assay for immunogenicity risk prediction and provides a framework for further refinement of a B cell-based assay for immunogenicity risk prediction of mAbs.

Food-borne zoonoses, particularly anisakiosis caused by Anisakis spp., are an increasing public health concern due to the rising consumption of raw fish. Anisakiosis results from the ingestion of third-stage larvae of Anisakidae nematodes, with the genus Anisakis re-sponsible for approximately 97% of human cases. While regulatory protocols exist to minimize infection risk in commercial settings, domestic food preparation often lacks such safeguards, creating a gap in public health protection. In the Canary Islands, a major Spanish aquaculture region, farmed fish exhibit a low Anisakis prevalence, suggesting minimal risk from aquaculture products. In contrast, wild-caught fish demonstrate varia-ble parasitism, with recent studies reporting a 25% prevalence among commercial species.

Methods: This study assessed Anisakis exposure in the Canary Islands by measuring specific IgG and IgE antibodies in 1043 serum samples collected from all seven islands between March 2014 and October 2015. ELISA assays detected anti-Anisakis antibodies, and the results were analyzed by age, sex, island, and isoclimatic zone.

Results: Overall, 16.9% of samples were IgG-positive and 6.8% were IgE-positive. Seroprevalence was significantly higher in indi-viduals aged 60 years and above. Geographic heterogeneity was notable: La Palma had the highest IgG seroprevalence (35.3%), while El Hierro showed the highest IgE prevalence (16.3%). Temperate isoclimatic zones exhibited higher antibody prevalence than dry zones. These findings indicate variable Anisakis exposure across the Canary Islands, likely influenced by environmental and behavioral factors.

Conclusions: The results highlight the need for targeted public health interventions to reduce the anisakiosis risk, particularly in regions and populations with elevated exposure.

Objectives: The durability and breadth of neutralizing antibodies following SARS-CoV-2 mRNA vaccination remain incompletely understood. This study aimed to investigate how longitudinal changes in antibody isotype composition impact neutralization against structurally diverse SARS-CoV-2 variants. Methods: After screening a broader cohort of mRNA-vaccinated sera, time-matched samples collected one month (1 mpv) and three months post-vaccination (3 mpv) were selected for detailed analysis. Neutralization assays against live virus variants, enzyme-linked immunosorbent assays (ELISA), and immunogold electron microscopy were performed to assess antibody titers, isotype levels, and virion morphology. Results: Neutralization titers declined markedly at 3 mpv, particularly against immune-evasive variants. Notably, the Lambda variant showed disproportionately high sensitivity to early-phase sera despite its divergence from the vaccine strain. Antibody isotyping showed that IgA and IgM decreased over time, while IgG levels were relatively more sustained. Electron microscopy revealed broader virion size heterogeneity in Lambda (50-200 nm) compared to Wuhan (80-120 nm), potentially enhancing multivalent antibody engagement. Consistently, ELISA under reduced spike density conditions showed that IgA and IgM retained stronger binding than IgG. Conclusions: These findings indicate that the decline of IgA and IgM compromises neutralization breadth, especially against structurally divergent variants such as Lambda. Sustaining dynamic multivalent isotype responses that adapt to diverse spike morphologies may be critical for broad cross-variant immunity.

Immunotherapy has emerged as a transformative approach in gastrointestinal (GI) cancers, addressing historically poor survival rates in advanced-stage disease. Immune checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 axis demonstrate remarkable efficacy in colorectal cancer with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), exemplified by trials like NICHE-2 achieving exceptional pathological response rates. However, significant limitations persist, including resistance in some dMMR/MSI-H tumors, minimal efficacy in proficient mismatch repair (pMMR) tumors, and low overall response rates across most GI malignancies due to tumor heterogeneity and immune evasion mechanisms. Predictive biomarkers such as tumor mutational burden (TMB) and PD-L1 expression are crucial for optimizing patient selection, while hypermutated pMMR tumors with POLE mutations represent emerging therapeutic opportunities. In pancreatic adenocarcinoma, where survival remains dismal, combination strategies with chemotherapy and novel approaches like cancer vaccines show promise but lack transformative breakthroughs. Esophagogastric cancers benefit from ICIs combined with chemotherapy, particularly in MSI-H and HER2-positive tumors, while hepatocellular carcinoma has achieved significant progress with combinations like atezolizumab-bevacizumab and durvalumab-tremelimumab surpassing traditional therapies. Biliary tract cancers show modest improvements with durvalumab-chemotherapy combinations. Despite these advances, immunotherapy faces substantial challenges including immune-related adverse events, acquired resistance through cancer immunoediting, and the need for biomarker-driven approaches to overcome tumor microenvironment barriers. This review discusses key clinical trials, therapeutic progress, and emerging modalities including CAR T-cell therapies and combination strategies, emphasizing the critical need to address resistance mechanisms and refine precision medicine approaches to fully realize immunotherapy's potential in GI malignancies.