Autoantibody mediated deficiency of IL-36-receptor antagonist in a subset of patients with psoriasis and psoriatic arthritis.

Objective: Psoriatic arthritis (PsA) is known as a seronegative form of spondylarthropathy. The interleukin-36 cytokine family may have a major role in disease pathogenesis and particularly the related cutaneous manifestations. In light of our recent observations on (transient) autoantibody phenotypes neutralizing endogenous anti-inflammatory receptor antagonists (progranulin, IL-1Ra) in different inflammatory conditions, we set out to investigate the potential role of such antibodies targeting IL-36 cytokine family members in PsA and psoriasis without arthritic manifestations (Pso).

An inherited genetic variant of the CEP72 gene is associated with the development of vincristine-induced peripheral neuropathy in female patients with aggressive B-cell lymphoma.

Vincristine-induced peripheral neuropathy (VIPN) is an adverse effect of regimens used for the treatment of aggressive B-cell non-Hodgkin lymphoma (B-NHL). A single-nucleotide polymorphism (SNP) in the promotor region of the CEP72 gene has been identified as risk factor for the development of VIPN in children. To validate these results in adults we aimed to determine the association of the high-risk CEP72 (rs924607 TT genotype) with the occurrence and severity of VIPN.

Hyper-N-glycosylated SEL1L3 as auto-antigenic B-cell receptor target of primary vitreoretinal lymphomas.

Primary vitreoretinal lymphoma (PVRL) is a rare subtype of DLBCL and can progress into primary central nervous system lymphoma (PCNSL). To investigate the role of chronic antigenic stimulation in PVRL, we cloned and expressed B-cell receptors (BCR) from PVRL patients and tested for binding against human auto-antigens. SEL1L3, a protein with multiple glycosylation sites, was identified as the BCR target in 3/20 PVRL cases.

Autoantibody-Mediated Depletion of IL-1RA in Still's Disease and Potential Impact of IL-1 Targeting Therapies.

Background: Adult-onset Still's disease (AOSD) and systemic juvenile idiopathic arthritis (sJIA) resemble a continuum of a rare, polygenic IL-1β-driven disease of unknown etiology.

Objective: In the present study we sought to investigate a potential role of recently described autoantibodies neutralizing the interleukin-1(IL-1)-receptor antagonist (IL-1-Ra) in the pathogenesis of Still's disease.

Methods: Serum or plasma samples from Still's disease patients (AOSD, n = 23; sJIA, n = 40) and autoimmune and/or inflammatory disease controls (n = 478) were analyzed for autoantibodies against progranulin (PGRN), IL-1Ra, IL-18 binding protein (IL-18BP), and IL-36Ra, as well as circulating IL-1Ra and IL-36Ra levels by ELISA.

B-cell receptor reactivity against in nodular lymphocyte-predominant Hodgkin lymphoma.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a Hodgkin lymphoma expressing functional B-cell receptors (BCR). Recently, we described a dual stimulation model of IgD+ lymphocyte-predominant cells by Moraxella catarrhalis antigen RpoC and its superantigen MID/hag, associated with extralong CDR3 and HLA-DRB1*04 or HLADRB1* 07 haplotype. The aim of the present study was to extend the antigen screening to further bacteria and viruses.

Ars2-containing bispecific, Fab- and IgG1-format BAR-bodies to target DLBCL cells.

Despite recent advances in the therapy of diffuse large B-cell lymphoma, not otherwise specified (DLBCL), around 30% of patients develop refractory disease or relapse after first-line treatment. Recently, Ars2 was reported as the auto-antigenic target of the B-cell receptor (BCR) in approximately 25% of activated B-cell DLBCL cases. Ars2 could be used to specifically target B cells expressing Ars2-reactive BCRs.

Autoantibodies against SUMO1-DHX35 in long-COVID.

Long COVID is a collection of symptoms as a late sequelae of SARS-CoV-2 infection. It often includes mental symptoms such as cognitive symptoms, persisting loss of smell and taste, in addition to exertional dyspnea. A role of various autoantibodies (autoAbs) has been postulated in long-COVID and is being further investigated.

B-cell receptors of EBV-negative Burkitt lymphoma bind modified isoforms of autoantigens.

Burkitt lymphoma (BL) represents the most aggressive B-cell-lymphoma. Beside the hallmark of -translocation, surface B-cell receptor (BCR) is expressed, and mutations in the BCR pathway are frequent. Coincidental infections in endemic BL, and specific extra-nodal sites suggest antigenic triggers.

Autoantibodies against interleukin-1 receptor antagonist in multisystem inflammatory syndrome in children: a multicentre, retrospective, cohort study.

Background: Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious complication of infection with SARS-CoV-2. A possible involvement of pathogenetically relevant autoantibodies has been discussed. Recently, neutralising autoantibodies against inflammatory receptor antagonists progranulin and interleukin-1 receptor antagonist (IL-1Ra) were found in adult patients with critical COVID-19.

KIR2DS1-HLA-C status as a predictive marker for benefit from rituximab: a post-hoc analysis of the RICOVER-60 and CLL8 trials.

Background: The addition of rituximab to chemotherapy has substantially improved outcomes for patients with B-cell malignancies. The mechanisms of action of rituximab include activation of natural killer cells. Killer-cell immunoglobulin-like receptors (KIRs) mediate natural killer cell function through interaction with HLA.

The B-cell Receptor Autoantigen LRPAP1 Can Replace Variable Antibody Regions to Target Mantle Cell Lymphoma Cells.

Mantle cell lymphoma (MCL) accounts for 5%-10% of all lymphomas. The disease's genetic hallmark is the t(11; 14)(q13; q32) translocation. In younger patients, the first-line treatment is chemoimmunotherapy followed by autologous stem cell transplantation.

LRPAP1 autoantibodies in mantle cell lymphoma are associated with superior outcome.

Low-density lipoprotein (LDL) receptor-related protein-associated protein 1 (LRPAP1) had been identified by B-cell receptor (BCR) expression cloning and subsequent protein array screening as a frequent and proliferation-inducing autoantigen of mantle cell lymphoma (MCL). Of interest, high-titered and light chain-restricted LRPAP1 autoantibodies were detected in 8 of 28 patients with MCL. In the present study, LRPAP1 autoantibodies in sera of patients treated within the Younger and Elderly trials of the European MCL Network were analyzed regarding frequency, association with disease characteristics, and prognostic impact.

Integration of the B-Cell Receptor Antigen Neurabin-I/SAMD14 Into an Antibody Format as New Therapeutic Approach for the Treatment of Primary CNS Lymphoma.

Recently, neurabin-I and SAMD14 have been described as the autoantigenic target of approximately 66% of B-cell receptors (BCRs) of primary central nervous system lymphomas (PCNSL). Neurabin-I and SAMD14 share a highly homologous SAM domain that becomes immunogenic after atypical hyper-N-glycosylation (SAMD14 at ASN339 and neurabin-I at ASN1277). This post-translational modification of neurabin-I and SAMD14 seems to lead to a chronic immune reaction with B-cell receptor activation contributing to lymphoma genesis of PCNSLs.

VEGFR2 and VEGFA polymorphisms are not associated with an inferior prognosis in Caucasian patients with aggressive B-cell lymphoma.

Purpose: Previous published data showed an impact of single-nucleotide polymorphisms in the VEGF A and VEGFR2 genes on the survival of patients with various malignancies, among others diffuse large B-cell lymphoma (DLBCL).

Patients And Methods: We investigated the role of four VEGF-A and two VEGFR-2 gene polymorphisms on the outcome of 273 patients with diffuse large B-cell lymphoma who were treated with R-CHOP within a prospective, randomized trial of the German High-Grade Non-Hodgkin Lymphoma Study Group (DSHNHL). The genomic DNA samples were analyzed using commercial DNA Probes (Applied Biosystems, USA) to detect single-nucleotide polymorphisms in the VEGF A rs699947, rs1570360, rs2010963, rs3025039 and rs1870377, and rs2305948 in the VEGFR2 receptor.

Identification of the atypically modified autoantigen Ars2 as the target of B-cell receptors from activated B-cell-type diffuse large B-cell lymphoma.

It has been suggested that B-cell receptor (BCRs) stimulation by specific antigens plays a pathogenic role in diffuse large B-cell lymphoma (DLBCL). Here, it was the aim to screen for specific reactivities of DLBCL-BCRs in the spectrum of autoantigens and antigens of infectious origin. Arsenite resistance protein 2 (Ars2) was identified as the BCR target of 3/5 ABC-type DLBCL cell lines and 2/11 primary DLBCL cases.

Lymphocyte predominant cells detect Moraxella catarrhalis-derived antigens in nodular lymphocyte-predominant Hodgkin lymphoma.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma of B-cell origin with frequent expression of functional B-cell receptors (BCRs). Here we report that expression cloning followed by antigen screening identifies DNA-directed RNA polymerase beta' (RpoC) from Moraxella catarrhalis as frequent antigen of BCRs of IgD LP cells. Patients show predominance of HLA-DRB1*04/07 and the IgVH genes encode extraordinarily long CDR3s.

Progranulin autoantibodies in systemic sclerosis and autoimmune connective tissue disorders: A preliminary study.

Objective: The present study aimed to investigate progranulin autoantibodies in systemic sclerosis and autoimmune connective tissue disorders. Progranulin is a physiologic tumor necrosis factor (TNF) antagonist. Progranulin antibodies decrease progranulin levels.

Saposin C is a frequent target of paraproteins in Gaucher disease-associated MGUS/multiple myeloma.

Patients with Gaucher disease (GD) have an increased risk of monoclonal gammopathies for which antigenic targets might play a role in their pathogenesis. Here we report the identification of saposin C (sapC) as high-titre (1:1 000 000) target structure of 7/16 GD-associated paraproteins. Anti-sapC immunoglobulin (Ig) showed identity with the paraprotein Ig type and subclass in each patient that showed anti-sapC immunoreactivity.

Hyper--glycosylated SAMD14 and neurabin-I as driver autoantigens of primary central nervous system lymphoma.

To address the role of chronic antigenic stimulation in primary central nervous system lymphoma (PCNSL), we searched for autoantigens and identified sterile α-motif domain containing protein 14 (SAMD14) and neural tissue-specific F-actin binding protein I (neurabin-I) as autoantigenic targets of the B-cell receptors (BCRs) from 8/12 PCNSLs. In the respective cases, SAMD14 and neurabin-I were atypically hyper--glycosylated (SAMD14 at ASN339 and neurabin-I at ASN1277), explaining their autoimmunogenicity. SAMD14 and neurabin-I induced BCR pathway activation and proliferation of aggressive lymphoma cell lines transfected with SAMD14- and neurabin-I-reactive BCRs.

LRPAP1 is a frequent proliferation-inducing antigen of BCRs of mantle cell lymphomas and can be used for specific therapeutic targeting.

The predominant usage of VH4-34 and V3-21 and reports of stereotyped CDR3s suggest a shared antigenic target of B-cell receptors (BCR) from mantle cell lymphomas (MCL). To identify the target antigens of MCL-BCRs, BCRs from 21 patients and seven MCL cell lines were recombinantly expressed and used for antigen screening. The BCRs from 8/21 patients and 2/7 MCL cell lines reacted specifically with the autoantigen low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1).

Autoantibodies against lamin C, NA14 and CK15 in primary vasculitides or autoimmune diseases with secondary vasculitis.

Objectives: Autoantibodies may play a role in the pathogenesis of primary vasculitides (PVs) like giant cell arteritis (GCA). We recently identified 3 cytoskeletal proteins (lamin C [laC], nuclear autoantigen of 14kD [NA14] and cytokeratin 15 [CK15]) as autoantigens in GCA and postulated a frequent autoantibody response against these antigens in PVs.

Methods: To test this hypothesis we studied a cohort of patients with PVs (n=61) and healthy individuals (n=27) for the presence of these autoantibodies using a recombinant cDNA expression library.