1. Exhausted natural killer cells in adult IgA vasculitisMatija Bajželj, Emanuela Senjor, Nika Boštic, Matjaž Hladnik, Snežna Sodin-Šemrl, Milica Perišić, Janko Kos, Alojz Ihan, Alojzija Hočevar, Andreja Nataša Kopitar, Katja Lakota, 2025, izvirni znanstveni članek Povzetek: Introduction. IgA vasculitis nephritis (IgAVN) manifests in up to 84% of adult patients with IgA vasculitis (IgAV) and is associated with an elevated risk of progression to chronic kidney failure. The underlying pathogenic mechanism of adult IgAVN in leukocytes remain largely uncharacterised. Although natural killer (NK) cells were investigated in paediatric IgAV, their specific role in the pathogenesis of adult IgAV has yet to be elucidated. Methods. RNA sequencing of leukocytes from adult IgAV patients and healthy controls (HC) was performed. NK cells’ cytotoxicity was assessed using calcein-AM stained K562 cells, and exocytosis was measured by LAMP-1/CD107a expression. Intracellular perforin and granzyme B were analyzed via flow cytometry, and cytokine secretion was measured by Luminex xMAP. Interferon-induced genes were validated with qPCR. Results. Principal component analysis (PCA) of leukocyte gene expression profiles distinguished IgAV patients from HC. Pathway enrichment analysis showed differences in patients’ subsets - Interferon signalling Reactome pathway was observed only in sample from patients with skin-limited IgAV (sl-IgAV) and was confirmed by increased expression of interferon-induced genes using qPCR. Only in samples from IgAVN patients enrichment of NK cell-mediated cytotoxicity KEGG pathway was found. NK cells from IgAVN patients showed significantly decreased cytotoxicity compared to samples from sl-IgAV patients (p = 2.53 × 10− 2). The % of CD107a+-NK cells significantly increased after stimulation in HC (p = 9.7 × 10− 3) and in sl-IgAV patient samples (p = 2.21 × 10− 2) while only a minor increase was observed in samples of IgAVN patients. IgAVN patients exhibited a decreased % of perforin+ NK cells compared to HC. Following phytohemagglutinin (PHA)/interleukin (IL)-2 stimulation, a significant reduction in intracellular perforin level was observed in HC (p = 2.53 × 10− 2), but not in IgAVN patients NK cells. Interferon (IFN)-ϒ and macrophage inflammatory protein (MIP)-1β were significantly decreased in NK cell culture supernatants from IgAVN patients (p = 2.64 × 10− 2 and p = 2.65 × 10− 2 respectively). Conclusion. Patients with IgAVN exhibited impaired cytotoxic and immunomodulatory functions of NK cells, along with a marked absence of interferon signaling in PBMCs. Further studies are needed to confirm if discrimination of patient subsets based on leukocyte samples might be of clinical use and if deregulated NK function might contribute to the pathogenesis of nephritis in adult IgAV.
Ključne besede: immunoglobulin A, IgAVN, IgA vasculitis, RNA sequencing, kidney diseases, immunoglobulins, killer cells, adults
Objavljeno v DiRROS: 12.11.2025; Ogledov: 312; Prenosov: 142
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2. Establishment of ELISA-comparable moderate and high thresholds for anticardiolipin and anti-β2 glycoprotein I chemiluminescent immunoassays according to the 2023 ACR/EULAR APS classification criteria and evaluation of their diagnostic performancePolona Žigon, Nika Boštic, Aleš Ambrožič, Žiga Rotar, Elizabeta Blokar, Manca Ogrič, Saša Čučnik, 2025, izvirni znanstveni članek Povzetek: Objectives: Recently published 2023 ACR/EULAR APS classification criteria emphasize the importance of quantifying single-, double-, and triple-antiphospholipid antibody positivity, distinguishing between IgG and IgM isotypes, and delineating moderate/high levels of anticardiolipin (aCL) and anti-β2 glycoprotein I (anti-β2GPI) antibodies. We aimed to establish clinically important moderate/high thresholds for aCL and anti-β2GPI IgG/IgM chemiluminescent immunoassays (CLIA), in particular QUANTA Flash, comparable to our in-house ELISAs used for over two decades, and to evaluate their diagnostic performance. Methods: QUANTA Flash CLIA and in-house ELISAs were used to measure aCL and anti-β2GPI IgG/IgM. Moderate thresholds for QUANTA Flash CLIA were determined using a non-parametric approach, calculating a 99th percentile on serum samples from 139 blood donors, and by mirroring the diagnostic performance of in-house ELISA on 159 patient samples. Results: Thresholds for QUANTA Flash CLIA achieving diagnostic performance equivalent to in-house ELISAs were 40 CU for moderate and 80 CU for high levels for aCL and anti-β2GPI IgG and IgM. The assays showed good qualitative agreement, ranging from 76.10 to 91.19 %. When considering in-house ELISA results, 14 out of 80 (17.5 %) patients did not fulfill the new ACR/EULAR laboratory classification criteria, while 27 out of 80 (33.8 %) did not when considering QUANTA Flash CLIA results. Conclusions: We determined moderate and high thresholds for aCL and anti-β2GPI IgG and IgM detected with QUANTA Flash CLIA, aligning with long-established in-house ELISA thresholds. These thresholds are crucial for seamlessly integrating of the new 2023 ACR/EULAR classification criteria into future observational clinical studies and trials.
Ključne besede: anti-β2GPI, anticardiolipin, antiphospholipid syndrome, classification criteria
Objavljeno v DiRROS: 10.11.2025; Ogledov: 253; Prenosov: 132
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