Euroimmun Medizinische Labordiagnostika (Germany)

[This corrects the article DOI: 10.3389/frdem.2024.1455619.].

Abstract BackgroundIn 2023, the FDA approved LEQEMBI, a monoclonal antibody therapy targeting beta‐amyloid plaques, for patients with early‐stage Alzheimer’s disease (AD). However, anti‐amyloid drug trials demonstrated an elevated risk for amyloid‐related imaging abnormalities with cerebral edema (ARIA‐E) in carriers of the AD risk allele apolipoprotein E epsilon 4 (APOE‐ɛ4), especially in ɛ4/ɛ4 homozygous individuals. Here, we report on the evaluation of a new real‐time polymerase chain reaction (PCR) test for APOE genotyping.MethodThe EURORealTime APOE (EUROIMMUN), which enables simultaneous testing for all six APOE genotypes (ɛ2/ɛ2, ɛ2/ɛ3, ɛ2/ɛ4, ɛ3/ɛ3, ɛ3/ɛ4, and ɛ4/ɛ4) by real‐time PCR, was performed using genomic DNA (gDNA) isolated from EDTA blood samples. The PCR amplification results were evaluated using the EURORealTime Analysis Software (EUROIMMUN). Samples from healthy blood donors (HBD) were used to assess intra‐assay, inter‐assay and between‐lot precision (n=6) as well as analytical sensitivity (n=21), with each APOE genotype represented by at least one sample. Assay accuracy was analyzed by comparing genotype assignments to the results of the CE‐IVD‐marked EUROArray APOE (EUROIMMUN) and bidirectional Sanger sequencing using 110 samples (100 AD, 10 HBD). APOE genotype frequencies were compared between patients (100 AD) and controls (250 HBD).ResultPrecision testing of the EURORealTime APOE resulted in 100% correct genotype calls. Assessment of the analytical sensitivity revealed valid and correct genotype assignment in all 21 samples, confirming 1 ng/µl as the recommended minimum gDNA concentration. The analytical accuracy amounted to 100% based on agreement with the two reference methods in 110/110 cases. Comparison of the APOE genotype distribution showed a higher proportion of ɛ4 allele carriers (i.e., ɛ2/ɛ4, ɛ3/ɛ4, and ɛ4/ɛ4) in AD patients than in HBD (50.0% vs. 25.2%). The prevalence of the ɛ4/ɛ4 genotype in these cohorts was 25.0% for AD patients compared with 2.8% for HBD.ConclusionThe well‐established high prevalence of the APOE‐ɛ4/ɛ4 genotype in AD patients, together with the increased risk of ARIA‐E in these homozygous carriers, substantiates the relevance of APOE genotyping prior to anti‐amyloid treatment. The EURORealTime APOE test provides sensitive and reliable determination of APOE alleles, thus presenting a suitable tool to improve risk stratification for potential LEQEMBI recipients.

Anti-p200 pemphigoid is an autoimmune blistering disease that often resembles other pemphigoid disorders. We developed a test for the detection of autoantibodies against laminin β4, an autoantigen in anti-p200 pemphigoid, to facilitate its diagnosis. The test demonstrated excellent sensitivity and specificity, making it a valuable tool for diagnosing this disease and distinguishing it from similar skin disorders.

BackgroundPurkinje cytoplasmic autoantibody type 1 (PCA-1)/anti-Yo autoimmunity is a common high-risk paraneoplastic neurological disorder, traditionally attributed antigenically to cerebellar degeneration–related protein 2 (CDR2), predominantly affecting women with gynecologic or breast adenocarcinoma. Single-modality CDR2 testing may produce false-positive results. We assessed the performance characteristics of the more recently purported major PCA-1/Yo antigen, CDR2-like (CDR2L), side by side with CDR2, in a line blot format.MethodsCDR2 and CDR2L were tested in six specimen groups (serum and cerebrospinal fluid (CSF)). Group 1, PCA-1/Yo mouse brain indirect immunofluorescence assay (IFA) positives; Group 2, PCA-1/Yo IFA mimics; Group 3, suspected CDR2 line blot false positives; Group 4, consecutive patient samples tested for neural antibodies over 1 year; Group 5, healthy subject serums; and Group 6, polyclonal (non-specific) immunoglobulin G (IgG)-positive serums.ResultsGroup 1: Of 64 samples tested, all but two were CDR2 positive (both CSF samples) and all were CDR2L positive. In individual patients, CDR2L values were always higher than CDR2. The two “CDR2L-only” positives were CSF samples with low titer PCA-1/Yo by IFA with serum negativity but with typical clinical phenotype. Group 2: All 51 PCA-1/Yo mimics were CDR2/CDR2L negative. Group 3: Nine samples [six of 1289 (0.47%) serums and three of 700 CSF samples (0.43%) were PCA-1/Yo IFA negative/CDR2 positive; two of the six available (serums from the same patient) were also CDR2L positive; the other four CDR2L negative had low CDR2 values (17–22). Group 4: Twenty-two patients had unexpected CDR2 or CDR2L positivity; none had tissue IFA positivity. Eleven of the 2,132 serum (0.5%) and three of the 677 CSF (0.4%) samples were CDR2 positive; median value was 19 (range, 11–48). Seven of the 2,132 serum (0.3%) and three of the 677 CSF (0.4%) samples were CDR2L positive; median value was 18 (range, 11–96). Group 5: All 151 healthy serum samples were negative. Group 6: One of the 46 polyclonal serum samples was CDR2L positive. Optimum overall performance was accomplished by requiring both CDR2 and CDR2L positivity in serum (sensitivity, 100%; and specificity, 99.9%) and positivity for CDR2L in CSF (sensitivity, 100%; and specificity, 99.6%).ConclusionCDR2L provides additional PCA-1/anti-Yo sensitivity in CSF, and dual positivity with CDR2 provides additional specificity assurance in serum. Combining antigen-specific and tissue-based assays optimizes PCA-1/anti-Yo testing.

Abstract Background Previous retrospective has been demonstrated the concentration of chemokine ligand CXCL13 in cerebrospinal fluid (CSF-CXCL13) is a promising biomarker in the diagnosis of neurosyphilis (NS) and monitoring of therapeutic efficacy. The goal of this study was to measure CXCL13 concentrations in CSF of NS suspected patients and compare with patients with syphilis non-NS and patients with treated syphilis. Methods One hundred and eleven NS-suspected participants from Rio de Janeiro (Brazil) were investigated for the detection of IgG antibodies against Treponema pallidum, using ELISA and Indirect Immunofluorescence tests (EUROIMMUN, Lübeck, Germany). CSF-CXCL13 concentration was prospectively performed by ELISA (EUROIMMUN, Lübeck, Germany) assay in all participants at baseline and in participants diagnosed with NS in follow-up visits at 3, 6, and 12 months after therapy. Results CSF-CXCL13 concentrations were significantly higher in patients with established NS presenting a median concentration of 207.4 pg/mL (IQR 69.3–1515.5 pg/mL) than in patients with syphilis non-NS with a median of 1.0 pg/mL (IQR 0.1–11.0 pg/mL, P < 0.001) or patients with treated syphilis with a median of 0.1 pg/mL (IQR 0.1–7.1 pg/mL, P < 0.001). The CSF-CXCL13 concentrations decreased after 3, 6 and 12 months of therapy compared to baseline in all cases of NS. The added concentration of CSF-CXCL13 above 62.8 pg/mL plus CSF-FTA-ABS reactivity agreed with diagnosis of NS in 88.9% of People Living with HIV (PLWHs) and plus CSF-TPHA reactivity agreed with the diagnosis of NS in 100% of HIV-uninfected patients. Conclusion The study suggests that the clinical use of CSF-CXCL13 is useful for supplementary biomarker for NS and as monitoring the effectiveness of NS therapy, especially in PLWHs with nonreactive CSF-VDRL, excluded other neurologic diseases.

Onychomycosis (OM) is a common fungal nail infection. Based on the rich mycobial diversity in healthy toenails, we speculated that this is lost in OM due to the predominance of a single pathogen. We used next generation sequencing to obtain insights into the biodiversity of fungal communities in both healthy individuals and OM patients. By sequencing, a total of 338 operational-taxonomic units were found in OM patients and healthy controls. Interestingly, a classifier distinguished three distinct subsets: healthy controls and two groups within OM patients with either a low or high abundance of Trichophyton. Diversity per sample was decreased in controls compared to cases with low Trichophyton abundance (LTA), while cases with a high Trichophyton abundance (HTA) showed a lower diversity. Variation of mycobial communities between the samples showed shifts in the community structure between cases and controls—mainly driven by HTA cases. Indeed, LTA cases had a fungal β-diversity undistinguishable from that of healthy controls. Collectively, our data provides an in-depth characterization of fungal diversity in health and OM. Our findings also suggest that onychomycosis develops either through pathogen-driven mechanisms, i.e., in HTA cases, or through host and/or environmental factors, i.e., in cases with a low Trichophyton abundance.

BackgroundEvidence shows that dysfunctional SSc keratinocytes contribute to fibrosis by altering dermal homeostasis (1, 2). Whether interleukin-25 (IL-25), an IL-17 family member regulating many epidermal functions (3), takes part in skin fibrosis is unknown.ObjectivesTo investigate the role of IL-25 in skin fibrosis.MethodsThe expression of IL-25 was evaluated by immunofluorescence and in situ hybridization in 10 SSc and 7 healthy donors (HD) skin biopsies. Epidermal equivalents (EE) reconstituted by primary HD keratinocytes were used as a model to study transcriptomic changes induced by IL-25 in the epidermis. RNA expression profile in EE was characterized by RNAseq. The conditioned medium (CM) from primary SSc and HD keratinocytes primed with IL-25 was used to stimulate fibroblasts. IL-6, IL-8, MMP-1, type-I collagen (col-I), and fibronectin production by fibroblasts was assessed by ELISA.ResultsSSc epidermis expressed lower levels of IL-25 compared to HD. In EE, IL-25 regulated several molecular pathways related to wound healing and extracellular matrix (ECM) remodeling. Compared to control CM, the CM from IL-25-primed keratinocytes enhanced the fibroblast production of MMP-1, IL-6, IL-8, but not of Col-I nor fibronectin. However, IL-25 significantly reduced the production of Col-I when applied directly to fibroblasts and partially inhibit α-smooth muscle actin (α-SMA) expression promoted by TGFβ. The activation of keratinocytes by IL-25 was receptor-dependent and evident after a very short incubation time (10 min), largely mediated by IL-1, suggesting enhanced and specific release of preformed mediators.ConclusionThese results show that IL-25 participates to skin homeostasis and its decreased expression in SSc may contribute to skin fibrosis by favoring ECM deposition over degradation.