Mass spectrometry-based identification of new anti-Ly and known antisynthetase autoantibodies.

OBJECTIVES: To discover new and detect known antisynthetase autoantibodies (ASAs) through protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS). METHODS: IP-MS was performed using sera of individuals showing features of antisynthetase syndrome (ASyS) without (n=5) and with (n=12) previously detected ASAs, and healthy controls (n=4). New candidate aminoacyl-tRNA-synthetase (ARS) autoantigens identified through unbiased IP-MS were confirmed by IP-western blot. A targeted IP-MS assay for various ASA specificities was developed and validated with sera of patients with known ASAs (n=16), disease controls (n=20) and healthy controls (n=25). The targeted IP-MS assay was applied in an additional cohort of patients with multiple ASyS features or isolated myositis without previously detected ASAs (n=26). RESULTS: Autoantibodies to cytoplasmic cysteinyl-tRNA-synthetase (CARS1) were identified by IP-MS and confirmed by western blot as a new ASA specificity, named anti-Ly, in the serum of a patient with ASyS features. Rare ASAs, such as anti-OJ, anti-Zo and anti-KS, and common ASAs could also be identified by IP-MS. A targeted IP-MS approach for ASA detection was developed and validated. Application of this method in an additional cohort identified an additional patient with anti-OJ autoantibodies that were missed by line and dot immunoassays. DISCUSSION: CARS1 is the dominant cognate ARS autoantigen of the newly discovered anti-Ly ASA specificity. Rare and common ASA specificities could be detected by both unbiased and targeted IP-MS. Unbiased and targeted IP-MS are promising methods for discovery and detection of autoantibodies, especially autoantibodies that target complex autoantigens.

Autoantibodies against the NineTeen complex and U5 RNP in systemic sclerosis.

ObjectiveMultiple spliceosome components are known autoantigens in systemic sclerosis (SSc). Here we aim to identify new and characterize rare anti-spliceosomal autoantibodies in patients with SSc without known autoantibody specificity. MethodsSera that precipitated spliceosome subcomplexes, as detected by immunoprecipitation-mass spectrometry (IP-MS), were identified from a database of 106 patients with SSc without known autoantibody specificity. New autoantibody specificities were confirmed with immunoprecipitation-western blot. The IP-MS pattern of new anti-spliceosomal autoantibodies was compared with anti-U1 RNP-positive sera of patients with different systemic autoimmune rheumatic diseases and anti-SmD-positive sera of patients with systemic lupus erythematosus (n = 24). ResultsThe NineTeen Complex (NTC) was identified and confirmed as new spliceosomal autoantigen in one patient with SSc. U5 RNP, as well as additional splicing factors, were precipitated by the serum of another patient with SSc. The IP-MS patterns of anti-NTC and anti-U5 RNP autoantibodies were distinct from those of anti-U1 RNP- and anti-SmD-positive sera. Furthermore, there was no difference in IP-MS patterns between a limited number of anti-U1 RNP-positive sera of patients with different systemic autoimmune rheumatic diseases. ConclusionAnti-NTC autoantibodies are a new anti-spliceosomal autoantibody specificity, here first identified in a patient with SSc. Anti-U5 RNP autoantibodies are a distinct but rare anti-spliceosomal autoantibody specificity. All major spliceosomal subcomplexes have now been described as target of autoantibodies in systemic autoimmune diseases.

Identification of new telomere- and telomerase-associated autoantigens in systemic sclerosis.

PURPOSE: In up to 20% of patients with systemic sclerosis (SSc) no known autoantibody specificity can be identified. Recently discovered autoantigens, such as telomeric repeat binding factor 1 (TERF1), as well as established autoantigens, like RuvBL1/2, are associated with telomere and telomerase biology. We aimed to identify new telomere- and telomerase-associated autoantigens in patients with SSc without known autoantibody specificity. METHODS: Unlabelled protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS) was performed with sera of 106 patients with SSc from two tertiary referral centres that had a nuclear pattern on HEp-2 indirect immunofluorescence without previously identified autoantibody. Telomere- or telomerase-associated proteins or protein complexes precipitated by individual sera were identified. Candidate autoantigens were confirmed through immunoprecipitation-western blot (IP-WB). A custom Luminex xMAP assay for 5 proteins was evaluated with sera from persons with SSc (n = 467), other systemic autoimmune rheumatic diseases (n = 923), non-rheumatic disease controls (n = 187) and healthy controls (n = 199). RESULTS: Eight telomere- and telomerase-associated autoantigens were identified in a total of 11 index patients, including the THO complex (n = 3, all with interstitial lung disease and two with cardiac involvement), telomeric repeat-binding factor 2 (TERF2, n = 1), homeobox-containing protein 1 (HMBOX1, n = 2), regulator of chromosome condensation 1 (RCC1, n = 1), nucleolar and coiled-body phosphoprotein 1 (NOLC1, n = 1), dyskerin (DKC1, n = 1), probable 28S rRNA (cytosine(4447)-C(5))-methyltransferase (NOP2, n = 1) and nuclear valosin-containing protein-like (NVL, n = 2). A Luminex xMAP assay for THO complex subunit 1 (THOC1), TERF2, NOLC1, NOP2 and NVL revealed high reactivity in all index patients, but also in other patients with SSc and disease controls. However, the reactivity by xMAP assay in these other patients was not confirmed by IP-WB. CONCLUSION: IP-MS revealed key telomere- and telomerase-associated proteins and protein complexes as autoantigens in patients with SSc.

Anti-TIF1-γ autoantibodies: warning lights of a tumour autoantigen.

Anti-transcription intermediary factor 1 (TIF1)-γ autoantibodies are robustly linked with cancer-associated DM in adults. This review aims to give an overview of the physiological context of TIF1-γ and to determine whether there is a pathophysiological link between anti-TIF1-γ autoantibodies and the occurrence of cancer. Detection of anti-TIF1-γ autoantibodies has a high sensitivity and specificity for cancer-associated DM in adults and is therefore useful for both diagnosis and cancer risk stratification. The function of the autoantigen, TIF1-γ, may provide insight into the mechanism behind this association. TIF1-γ is a ubiquitously present protein involved in various biological pathways, including TGF-ß signalling. In cancer, it can act either as a tumour suppressor or promoter, depending on the cellular context and cancer stage. Evolving data provide pathophysiological insights, linking anti-TIF1-γ autoantibodies to both the anti-tumour response and to muscle and skin damage. TIF1-γ expression is increased in muscle and skin tissue of patients with DM. Mutations or loss-of-heterozygosity in TIF1-γ alleles in malignant tissue may result in the expression of tumour-specific neo-antigens stimulating autoantibody production. The newly formed autoantibodies are hypothesized to cross-react with antigens in muscle and skin, driving the development of DM. Based on the current evidence, anti-TIF1-γ autoantibodies should be considered warning lights of a potential tumour autoantigen and should alert the physician to the possibility of an underlying cancer.

Detection of circulating anti-skin antibodies by indirect immunofluorescence and by ELISA: a comparative systematic review and meta-analysis.

Background Both enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) are available for the diagnosis of autoimmune bullous diseases (AIBD). Many studies have reported on the performance of ELISAs and concluded that ELISAs could replace IIF. This study compares the diagnostic accuracy of ELISA and IIF for the detection of autoantibodies to desmoglein 1 (DSG1), desmoglein 3 (DSG3), bullous pemphigoid antigen 2 (BP180) and bullous pemphigoid antigen 1 (BP230) to support the diagnosis of pemphigus vulgaris (PV), pemphigus foliaceus (PF) and bullous pemphigoid (BP). Methods A literature search was performed in the PubMed database. The meta-analysis was performed using summary values and a bivariate random effect model. Results The five included studies on PV did not demonstrate significant differences between IIF and DSG3-ELISA (sensitivity 82.3% vs. 81.6%, p = 0.9284; specificity 95.6% vs. 93.9%, p = 0.5318; diagnostic odds ratio [DOR] 101.60 vs. 67.760, p = 0.6206). The three included studies on PF did not demonstrate significant differences between IIF and DSG1-ELISA (sensitivity 80.6% vs. 83.1%, p = 0.8501; specificity 97.5% vs. 93.9%, p = 0.3614; DOR 160.72 vs. 75.615, p = 0.5381). The eight included studies on BP showed that BP230-ELISA differed significantly from both IIF on monkey esophagus (MO) and BP180-ELISA with regard to DOR (11.384 vs. 68.349, p = 0.0008; 11.384 vs. 41.699, p = 0.0125, respectively) Conclusions Our meta-analysis shows that ELISA performs as well as IIF for diagnosing PV, PF and BP.

Disease-associated mutations identify a novel region in human STING necessary for the control of type I interferon signaling.

BACKGROUND: Gain-of-function mutations in transmembrane protein 173 (TMEM173) encoding stimulator of interferon genes (STING) underlie a recently described type I interferonopathy called STING-associated vasculopathy with onset in infancy (SAVI). OBJECTIVES: We sought to define the molecular and cellular pathology relating to 3 individuals variably exhibiting the core features of the SAVI phenotype including systemic inflammation, destructive skin lesions, and interstitial lung disease. METHODS: Genetic analysis, conformational studies, in vitro assays and ex vivo flow-cytometry were performed. RESULTS: Molecular and in vitro data demonstrate that the pathology in these patients is due to amino acid substitutions at positions 206, 281, and 284 of the human STING protein. These mutations confer cGAMP-independent constitutive activation of type I interferon signaling through TBK1 (TANK-binding kinase), independent from the alternative STING pathway triggered by membrane fusion of enveloped RNA viruses. This constitutive activation was abrogated by ex vivo treatment with the janus kinase 1/2 inhibitor ruxolitinib. CONCLUSIONS: Structural analysis indicates that the 3 disease-associated mutations at positions 206, 281, and 284 of the STING protein define a novel cluster of amino acids with functional importance in the regulation of type I interferon signaling.

Effects of implementing a vaccination tool in the electronic medical record on vaccination coverage of patients with immune-mediated inflammatory diseases: a prospective cohort study.

BACKGROUND: The rising incidence of immune-mediated inflammatory diseases (IMID) requires innovative management strategies, including effective vaccination. We aimed to assess the impact of an electronic medical record (EMR)-integrated vaccination tool on vaccination coverage among patients with inflammatory bowel diseases (IBD), rheumatological and dermatological conditions. METHODS: A prospective observational study compared vaccination coverage before (2018) and after (2021) implementing the module. Vaccination data for influenza, pneumococcus, hepatitis B and tetanus, and potential predictors were collected from 1430 IMID patients (44.9% male, median age (interquartile range [IQR]) 54 (40-66) years, 789 with IBD, 604 with rheumatological and 37 with dermatological conditions). Data were analysed using McNemar, chi-square tests and multinominal logistic regression. RESULTS: Significant increases in pneumococcus (56.6% to 73.1%, p < .001) and hepatitis B vaccination (62.2% to 75.9%, p < .001) were observed. Influenza vaccination rates increased among IBD (76.2% to 80.5%, p = .006) but remained stable overall (73.1% to 73.2%, p = 1.000). Tetanus vaccination rates decreased (71.5% to 55.0%, p < .001). The proportion of fully vaccinated patients (against influenza in the past year for patients >50 years old and/or under immunosuppressive therapy, against pneumococcus in the past 5 years for patients >65 years old and/or under immunosuppressive therapy and additionally against hepatitis B for IBD patients) rose from 41.3% to 54.8% (p < .001 all using McNemar). Factors associated with vaccinations included age, immunosuppressive therapy and education level. CONCLUSIONS: Increased vaccination coverage was measured after implementing the vaccination tool. The COVID19 pandemic and the 2018 measurement might have increased vaccination awareness. Education of patients and healthcare professionals remains crucial.

Proposition of standardized protocol for photodynamic therapy for vulvar lichen sclerosus.

BACKGROUND: Photodynamic therapy (PDT) is an alternative treatment modality for vulvar lichen sclerosus (VLS) which is a chronic inflammatory mucosal condition. In literature, no consensus of optimal parameters of PDT for VLS is reached so far. OBJECTIVES: The aim of this narrative review is to develop a standardized treatment protocol for PDT in VLS. METHODS: A systematic literature search was conducted to identify studies reporting on PDT in VLS and used treatment parameters, side-effects, and clinical outcomes were summarized. RESULTS: Thirteen studies used 5-aminolevulinic acid (5-ALA) with concentrations of 20%, 10%, 5% and three studies used methyl aminolevulinate (MAL). Generally, the light source was red light (median 630 nm). Light dose varied between 9 and 180 J/cm2 and light intensity between 40 and 700 mW/cm2. Incubation period with the photosensitizer ranged from 2 to 6 h. All studies showed a substantial improvement in VLS-related pruritus, burning and pain. CONCLUSIONS: Based on a literature review, we suggest the following protocol for PDT in VLS: 5% 5-ALA as a photosensitizer applied for 3 h under occlusion before irradiation at the dose of 120 J/cm2 with red light (590-760 nm) and intensity of 204 mW/cm2.

Correct approach in urticarial vasculitis made early diagnosis of lupus nephritis possible: a case report.

BACKGROUND: Urticarial vasculitis is a clinicopathologic entity defined by recurrent episodes of urticarial lesions that persist > 24 hours and demonstrate the histopathologic features of leukocytoclastic vasculitis. The most important prognostic feature is the presence of normo- or hypocomplementemia. In the latter, patients are much more likely to have systemic manifestations. Urticarial vasculitis is most often idiopathic, but it can arise in association with autoimmune connective diseases, cryoglobulinemia, infections, medications, and hematologic malignancies. CASE PRESENTATION: We present the case of a 61-year-old Caucasian woman with a skin eruption that consisted of erythematous plaques on the trunk and limbs that lasted > 24 hours but were asymptomatic. The skin eruption had an acute onset and persisted for 3 months upon initial presentation in our dermatology department. A punch biopsy showed signs of a leukocytoclastic vasculitis in the superficial dermis. On laboratory examination, signs of activation of the complement system were found with low complement C3, C4, and C1q, and with a high anti-C1q antibody titer. The clinical, histological, and lab results fit the diagnosis of hypocomplementemic urticarial vasculitis. There was also a positive antinuclear factor with elevated U1 small nuclear ribonucleoprotein and high double-stranded DNA determined by Farr method. On urinalysis, marked proteinuria and massive hematuria were found. Kidney biopsy showed focal crescentic and focal mesangial type of glomerular damage with a full-blown positivity of immunoglobulin A, immunoglobulin G, and C1q, leading to lupus nephritis class III-A (according to the International Society of Nephrology/Renal Pathology Society 2003 classification of lupus nephritis). The patient was treated with hydroxychloroquine, corticosteroids, and low-dose intravenous cyclophosphamide (Euro-Lupus regimen) as remission-inducing agent, followed by azathioprine as remission-maintaining agent. This treatment regimen gave good results, with total clearance of the skin lesions and remission of the lupus nephritis. CONCLUSION: Clinicopathologic recognition of urticarial vasculitis with correct screening for extracutaneous disease can lead to early diagnosis of serious organ involvement and thereby improve prognosis for the patient.

Detection of multiple myositis-specific autoantibodies in unique patients with idiopathic inflammatory myopathy: A single centre-experience and literature review: Systematic review.

INTRODUCTION: Myositis-specific autoantibodies (MSAs) are thought to be mutually exclusive in patients with idiopathic inflammatory myopathies (IIM) based on studies with immunoprecipitation-based (IP) detection methods. Recently, detection of multiple MSAs in unique patients is increasingly reported, but the extent of this phenomenon remains unclear. METHODS: At our centre, we reviewed results from two line immunoassays and one dot immunoassay in 145 IIM patients and 240 controls for the presence of multiple MSAs. Pubmed and Embase were systematically searched for articles mentioning detection of multiple MSAs in IIM patients, published until February 2019. We assessed the frequency, detection method, the precise combinations and clinical phenotypes of participants with multiple MSAs. RESULTS: At our centre, detection of multiple MSAs occurred in 3.4-8.3% of patients with IIM, depending on the assay. However, no cases with full concordance across all three assays were identified. Forty-four articles reported detection of multiple MSAs, representing a total of 133 cases, including four patients with a connective tissue disease other than IIM and two healthy controls. In 101 cases all MSAs were detected using only one detection method: 40 cases with IP-based methods (most frequently used technique) and 61 cases with other assay types. In most cases the phenotype of patients with multiple MSAs matched the predicted presentation associated with one MSA and in few cases the phenotype matched with both MSAs. CONCLUSION: Detection of multiple MSAs in unique IIM patients is less rare than commonly accepted. Specificity issues of the commercially available multiplex immunoassays may, at least partly, explain the higher frequency compared to IP-based methods. 'True multiple MSA-positive' patients may exist, though they are most likely rare.

Scleroderma-like cutaneous lesions during treatment with paclitaxel and gemcitabine in a patient with pancreatic adenocarcinoma. Review of literature.

BACKGROUND: Chemotherapy-induced skin sclerosis is generally not associated with other manifestations of systemic sclerosis. It is featured by skin sclerosis without visceral involvement (i.e., Raynaud's phenomenon, esophageal dysmotility, and pulmonary fibrosis), temporal association with chemotherapy administration, and the absence of detectable autoantibodies. The clinical course of scleroderma-like changes induced by paclitaxel or gemcitabine are refractory to treatment and commonly progressive, even after discontinuation of the triggering drugs. OBJECTIVE: Report a case of scleroderma-like cutaneous lesions during combination treatment with nab-paclitaxel and gemcitabine in a patient with pancreatic adenocarcinoma and determine other published cases of scleroderma-like skin changes following treatment with nab-paclitaxel, paclitaxel, or gemcitabine through the period from 2002 to 2018. METHODS: Literature search from the year 2002 onwards using combinations of "Scleroderma" AND "paclitaxel," AND/OR "gemcitabine." RESULTS: Additional to our case report we reviewed 14 other cases in the literature. Most of these cases share three prominent features: skin sclerosis without systemic involvement, temporal association with chemotherapy administration, and absence of detectable scleroderma-specific autoantibodies. CONCLUSION: To our knowledge, this is the first case report of scleroderma-like cutaneous lesions during combination treatment with nab-paclitaxel and gemcitabine in a patient with pancreatic adenocarcinoma. However, given the current literature, these scleroderma-like lesions are most likely induced by nab-paclitaxel or paclitaxel, rather than by gemcitabine.

Dermal fibroblasts pretreated with a sterol Delta7-reductase inhibitor produce 25-hydroxyvitamin D3 upon UVB irradiation.

As dermis is a physiological site of vitamin D3 photoproduction, the photo-endocrine vitamin D3 system was studied in dermal fibroblasts. Dermal fibroblasts contain the vitamin D receptor and induce 1alpha,25-dihydroxyvitamin D3-24-hydroxylase [CYP24] mRNA upon stimulation with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. In addition, dermal fibroblasts contain mRNA of the vitamin D3-25-hydroxylases (CYP2R1 and CYP27A1). However, we could not detect any 25-hydroxyvitamin D3 [25OHD3]-1alpha-hydroxylase mRNA in dermal fibroblasts and no CYP24 mRNA was induced upon ultraviolet [UVB] irradiation, even when endogenous 7-dehydrocholesterol content was elevated by pretreatment with the sterol Delta7-reductase inhibitor BM15766. Nevertheless, dermal fibroblasts produce inactive vitamin D3 metabolites that can be activated by epidermal keratinocytes as CYP24 mRNA is induced in epidermal keratinocytes but not in dermal fibroblasts after transfer of medium or cellular suspensions from BM15766-pretreated, UVB-irradiated fibroblasts. This CYP24 induction was UVB-dose dependent and was inhibited by ketoconazole. As revealed in a competitive binding assay, BM15766-pretreated dermal fibroblasts are able to produce 25OHD3 upon UVB irradiation, but no 1,25(OH)2D3 was detected via combined high-performance liquid chromatography radioimmunoassay. The physiological relevance of dermal vitamin D3 photoproduction and its subsequent conversion into 25OHD3 remains elusive.