Anti-survival motor neuron complex antibodies as a novel biomarker for pulmonary arterial hypertension and interstitial lung disease in mixed connective tissue disease

OBJECTIVE

The presence of anti-U1 RNP antibodies (Abs) is critical for diagnosing MCTD. The aim of this study is to evaluate the clinical relevance of anti-survival motor neuron (SMN) complex Abs, which often coexist with anti-U1 RNP Abs.

METHODS

A total of 158 newly diagnosed consecutive cases of SLE, SSc or MCTD with anti-U1 RNP Abs were enrolled in this multicentre observational study between April 2014 and August 2022. Serum anti-SMN complex Abs were screened by immunoprecipitation of 35S-methionine-labelled cell extracts, and associations between anti-SMN complex Abs positivity and clinical characteristics were analysed.

RESULTS

Anti-SMN complex Abs were detected in 36% of MCTD patients, which was significantly higher than that in SLE (8%) or SSc (12%). Among MCTD patients classified based on the combination of the clinical features of SLE, SSc and idiopathic inflammatory myopathies, anti-SMN complex Abs showed the highest prevalence in a subset with clinical features of all three components. Anti-SMN complex Abs-positive MCTD had a higher prevalence of pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD), which are related to poor prognosis, than negative patients. Moreover, all three cases of death within 1 year of the treatment were positive for anti-SMN complex Abs.

CONCLUSIONS

Anti-SMN complex Abs is the first biomarker of a typical subset of MCTD which bears organ damages such as PAH and ILD.

Estimation of genetic parameters for bull conception rate and its genetic correlations with semen production traits in Japanese Black bulls

The P of achieving pregnancy is an important trait of bull fertility in beef cattle and is defined as the bull conception rate (BCR). This study aimed to clarify and better understand the genetic architecture of the BCR calculated using artificial insemination and pregnancy diagnosis records from a progeny testing program in Japanese Black bulls. In this study, we estimated the genetic parameters of the BCR and their correlation with semen production traits. In addition, we assessed the correlated responses in BCR by considering the selection of semen production traits. Nine hundred and sixteen Japanese Black bulls were selected based on fertility, with 28 869 pregnancy diagnostic records from the progeny testing program. Our results showed that the heritability estimate was 0.04 in the BCR at the first service and 0.14 in BCR for the three services, and an increase in the inbreeding coefficient led to a significant decrease in BCR. The phenotypic trend of BCR remained almost constant over the years, whereas the genetic trend increased. In addition, the changes in the progeny testing year effect showed a similar tendency to the phenotypic trends, suggesting that the phenotypic trends could be mainly due to non-genetic effects, including progeny testing year effects. The estimated genetic correlation of BCR with sperm motility traits was favorably moderate to high (ranging from 0.49 to 0.97), and those with sperm quantity traits such as semen volume were favorably low to moderate (ranging from 0.23 to 0.51). In addition, the correlated responses in BCR at the first service by selection for sperm motility traits resulted in a higher genetic gain than direct selection. This study provides new insights into the genetic factors affecting BCR and the possibility of implementing genetic selection to improve BCR by selecting sperm motility traits in Japanese Black bulls.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Analytic and Clinical Validity of Myositis-Specific Antibodies by Line-Blot Immunoassay Is Essential

OBJECTIVES

This study assessed the concordance between line blot (LB) and immunoprecipitation (IP) assays for detecting myositis-specific antibodies (MSAs) in idiopathic inflammatory myopathies (IIMs) and their association with IIM subtypes.

METHODS

One hundred patients with IIM were enrolled, and MSA was detected using LB and IP. The IIM subtypes, including immune-mediated necrotizing myopathy-like, anti-tRNA synthetase syndrome-like, and clinically amyopathic dermatomyositis-like, were clinically diagnosed. The validity and reliability of the LB compared with the IP were evaluated. Optimal cutoff levels for LB were determined using various statistical methods including Cohen κ, Gwet's AC, diagnostic odds ratios, and receiver operating characteristic analysis.

RESULTS

Line blot exhibited lower specificity and accuracy than IP in predicting IIM subtypes. Some MSAs performed better at higher LB cutoff values. Anti-signal recognition particle antibodies showed poor performance in predicting the immune-mediated necrotizing myopathy-like subtype using LB. Raising the cutoffs improved the reliability of anti-threonyl-tRNA synthetase and anti-signal recognition particle antibodies. Anti-histidyl-tRNA synthetase antibodies performed well at lower positivity, whereas diagnostic odds ratios increased for anti-transcription intermediary factor 1γ and anti-nuclear matrix protein 2 with higher cutoffs.

CONCLUSIONS

Inconsistencies between LB and IP have been observed in patients with IIM. Individual optimal cutoffs for MSA by LB correlating with IP were determined. Rheumatologists should consider the differences between LB and IP results when classifying IIM subtypes.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Update on autoantibodies and related biomarkers in autoimmune inflammatory myopathies

Purpose of review

This manuscript reviews recently published advances in the identification of autoimmune inflammatory myopathies (AIM)-specific and AIM-related autoantibodies considered of value in the workup of patients suspected of having AIM. Newer autoantibodies, developments, and advances in the methodology of testing, the gaps and pitfalls in using these assays as diagnostic biomarkers, and the importance of considering overlap diseases and unique clinical AIM phenotypes are discussed.

Recent findings

Summary

The spectrum of autoantibodies and related biomarkers in AIM continues to expand. Many of these have clear clinical implications in regard to subsets and overlap conditions of AIM, associated malignancy and pathological findings.

Anti-SMN autoantibodies in mixed connective tissue disease are associated with a severe systemic sclerosis phenotype

OBJECTIVES

The survival of motor neuron (SMN) complex has an essential role in the assembly of small nuclear ribonucleoproteins (RNP). Recent reports have described autoantibodies (aAbs) to the SMN complex as novel biomarkers in anti-U1RNP+ myositis patients. The aim of this study was to compare phenotypic features of anti-U1RNP+ mixed connective tissue disease (MCTD) patients with and without anti-SMN aAbs.

METHODS

A retrospective MCTD cohort was studied. Addressable laser bead immunoassay was used to detect specific anti-SMN aAbs with <300 mean fluorescence intensity (MFI) as normal reference range, 300-999 MFI as low-titre and ≥1000 MFI as high-titre positivity. Comparison of clinical features between anti-SMN+ and anti-SMN- subgroups used two-tailed Fisher's exact test, and logistic regression analyses.

RESULTS

Sixty-six patients were included. Median age at MCTD diagnosis was 40.6 years, and duration of follow-up was 12 years. Based on the highest available titre, 39 (59%) were anti-SMN+: 10 (26%) had low titre and 29 (74%) had high titre. Anti-SMN+ patients had a higher frequency of fingertip pitting scars (anti-SMN+ 23% vs anti-SMN- 4%, p=0.04), lower gastrointestinal (GI) involvement (26% vs 4%, p=0.04), and myocarditis (16% vs 0%, p=0.04). The combined outcome of pitting scars and/or lower GI involvement and/or myositis and/or myocarditis was highest among high-titre anti-SMN+ patients: adjusted OR 7.79 (2.33 to 30.45, p=0.002).

CONCLUSIONS

Anti-SMN aAbs were present in 59% of our MCTD cohort. Their presence, especially at high-titres, was associated with a severe systemic sclerosis (scleroderma) phenotype including myositis, myocarditis and lower GI involvement.

Detection of antinuclear antibodies: recommendations from EFLM, EASI and ICAP

OBJECTIVES

Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA).

METHODS

A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group "Autoimmunity Testing"; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP).

RESULTS

In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations.

CONCLUSIONS

These recommendations are an important step to achieve high quality ANA testing.

Analysis of COVID-19 mRNA Vaccine-induced Mouth Ulcers Using the Japanese Adverse Drug Event Report Database

There are case reports of mouth ulcers caused by the coronavirus disease 2019 (COVID-19) messenger ribonucleic acid (mRNA) vaccine; however, the actual number and characteristics of cases are unknown. Therefore, we examined this issue using the Japanese Adverse Drug Event Report (JADER), a large Japanese database. We calculated the reported odds ratio (ROR) of drugs that may be specifically associated with mouth ulcers and assumed that a signal was present if the lower limit of the calculated ROR's 95% confidence interval (CI) was > 1. In addition, the time to symptom onset after administration of the COVID-19 mRNA and influenza HA vaccines was investigated. We found that the JADER database contained 4,661 mouth ulcer cases between April 2004 and March 2022. The COVID-19 mRNA vaccine was the eighth most common causative drug for mouth ulcers, with 204 reported cases. The ROR was 1.6 (95% CI, 1.4-1.9) and a signal was detected. There were 172 mouthulcer cases associated with the Pfizer-BioNTech's COVID-19 mRNA vaccine, 76.2% of which were female. The outcome was no unrecovered cases with the influenza HA vaccine, whereas the COVID-19 mRNA vaccine showed unrecovered cases (Pfizer-BioNTech: 12.2%, Moderna: 11.1%). The median time-to-onset of the mouth ulcers was two days for the COVID-19 mRNA vaccine and one day for the influenza HA vaccine, indicating that mouth ulcers caused by the COVID-19 mRNA vaccine were delayed adverse events. In this study, the COVID-19 mRNA vaccine was shown to cause mouth ulcers in a Japanese population.

The structure and modified properties of a self-dimerised Cu(II) inclusion complex in γ-cyclodextrins

Inclusion structures incorporating more than one guest molecule are elusive because confinement alters their molecular properties. We report the solid-state characterization of an inclusion complex comprising two γ-cyclodextrins and two [Cu(2-pyridinemethanolate)(2-pyridinemethanol)]PF₆ units. Quantum calculation reveals that interfragment charge transfer occurs. The confined Cu fragment and the unincluded "linear chain [Cu(2-pyridinemethanolate)(2-pyridinemethanol)]PF₆" exhibit different properties.

Association between antinuclear antibody positivity and chemical exposure among pregnant Japanese women: A cross-sectional study based on the Japan environment and Children's study

Antinuclear antibodies (ANAs) are detected in healthy individuals, they are more prevalent in women than in men. Pregnant women are immunologically unique, but epidemiological data on ANA positivity in them remain limited. The exposure received from the mother during the fetal period impacts the future health of the fetus and has thus received increased attention in recent years. Thus, we investigated the association between ANA positivity and chemical exposure among pregnant Japanese women, registered in the Japan Environment and Children's Study (JECS). ANA titers were assessed by indirect immunofluorescence with HEp-2 cells at a cutoff dilution of 1:40. Sociodemographic and other data were obtained in the JECS from a self-administered questionnaire. We analyzed 1,235 Japanese women in their first trimester of pregnancy. The ANA prevalence was 17.2%. Among ANA-positive women, a speckled pattern was the most common (95.3%), followed by a homogeneous pattern (72.3%). Exposure to chemicals more than once a week significantly increased the probability of ANA positivity (kerosene, petroleum, benzene, or gasoline: adjusted odds ratio [AOR], 2.11; 95% confidence interval [95% CI], 1.03-4.34; chlorine bleach or germicide: AOR, 1.97; 95% CI, 1.10-3.54; organic solvents: AOR, 5.34; 95% CI, 1.40-20.36; and photocopying machines or laser printers: AOR, 1.73; 95% CI, 1.17-2.54). ANA positivity was associated with exposure to several chemicals in Japanese women. Our exploratory results suggested that ANAs as potential markers of chemical exposure warrant further research.

Clinical significance of serum autoantibodies in patients with sarcoidosis

BACKGROUND

The association between sarcoidosis and autoimmunity has been reported for years. However, the significance of autoantibodies in the pathophysiology and clinical management of sarcoidosis is not well understood. No autoantibodies that can be used as serologic biomarkers to diagnose the disease, monitor the state of the disease, and predict the prognosis of patients are established.

METHODS

We performed a comprehensive analysis of serum autoantibodies and analyzed their associations with clinical features of sarcoidosis.

RESULTS

Patients with systemic autoimmune rheumatic diseases-associated autoantibodies had a higher prevalence of advanced radiographic stage and consolidations in high-resolution computed tomography than patients without autoantibodies (p < .05). Age, sex, clinical history, pulmonary function tests, serum angiotensin-converting enzyme levels, rheumatoid factor, and the number of involved organs were not significantly different between the two groups.

CONCLUSIONS

There may be an association between autoantibodies and more advanced pulmonary lesions in patients with sarcoidosis. Further investigations are needed to establish the significance of autoantibodies.

Myositis with prominent B cell aggregates may meet classification criteria for sporadic inclusion body myositis

The objective of this study was to report the clinical, serological and pathological features of patients with autoimmune myositis other than dermatomyositis, who displayed both muscle weakness on physical examination and prominent B cell aggregates on muscle pathology, defined as ≥ 30 CD20+ cells/aggregate. Specifically, the presence of a brachio-cervical inflammatory myopathies or a sporadic inclusion body myositis (sIBM) phenotype was recorded. Over a three-year period, eight patients were identified from two university neuropathology referral centers. Seven of 8 (88%) patients had an associated connective tissue disease (CTD): rheumatoid arthritis (n=3), systemic sclerosis (n=2), Sjögren's syndrome (n=1) and systemic lupus erythematosus (n=1), while one patient died on initial presentation without a complete serological and cancer investigation. A brachio-cervical phenotype, i.e. neck weakness, proximal weakness more than distal and shoulder abduction weakness greater than hip flexors, was seen in two patients (25%), while one patient had both proximal and diaphragmatic weakness. In contrast, an IBM-like clinical phenotype was seen in the last five patients (63%), who either had finger flexor weakness and/or quadriceps weakness ≤ 4 on the manual muscle testing MRC-5 scale. Although these 5 patients met at least one set of classification criteria for sIBM, an integrated clinico-sero-pathological approach argued against a diagnosis of sIBM. In summary, in a weak patient with myositis plus an associated CTD and lymphoid aggregates at muscle pathology, B cell predominant aggregates may represent a morphological biomarker against a diagnosis of sIBM.

[Allergy and immunotoxicology in preventive and clinical medicine from theory to practice: Occupational allergy and isocyanate-induced asthma]

Genetic and environmental factors and their interactions cause diseases and deteriorate health (Genetic and Environmental Interaction). Exposure to environmental factors plays a major role in the deterioration of health in the workplace.Occupational asthma (OA) is a common disorder in the workplace. Approaches to OA are well described and discussed in "Japanese Guideline for Diagnosis and Management of Occupational Allergic Diseases" by the Japanese Society of Occupational and Environmental Allergy. According to the guideline, OA and work-aggravated asthma comprise work-related asthma, and OA can be further divided into two disease entities: sensitizer-induced OA and irritant-induced OA. The guidelines also describe diagnostic and therapeutic strategies for OA. Since a definitive diagnosis of OA requires a comprehensive decision based on a detailed interview on clinical symptoms related to employment status and clinical tests, including inhalation tests of suspected substances as needed, the possibility of OA should be considered as the first step toward diagnosis of the patient. Otherwise, OA may not be diagnosed. Therapeutic strategies include exposure avoidance, environmental arrangements in the workplace, utilization of social resources for workers, and conventional pharmacotherapy for asthma.Artificially synthesized small compounds are used in various industries and can cause allergies. For example, isocyanates are small compounds in the -NCO group, which have been toxicologically studied. It was later shown that isocyanate could cause various nontoxic adverse health effects, including allergic reactions. Since small agents with low molecular weights bind to proteins, detecting their specific immunoglobulin E (IgE) antibodies targeting small compounds is generally difficult. In contrast, isocyanate-specific IgE antibodies are detectable in individuals with isocyanate allergies.Suspecting OA is essential in cases exposed to newly synthesized compounds, or to those that are already known but applied to new uses, which can be better understood and predicted by studying the health effects of isocyanates.Academic interest in various issues related to allergies, immunology, and toxicology in the workplace includes clinical medicine, epidemiology, and epigenetics related to environmental exposure. Further advanced research in these areas is necessary and promising.

Deciphering the Autoantibody Response to the OJ Antigenic Complex

(1) Background: Myositis specific antibodies (MSA) are important diagnostic biomarkers. Among the rarest and most challenging MSA are anti-OJ antibodies which are associated with anti-synthetase syndrome (ASS). In contrast to the other tRNA synthetases that are targets of ASS autoantibodies (e.g Jo-1, PL-7, PL-12, EJ, KS, Zo), OJ represents a macromolecular complex with several ribonucleoprotein subunits. Therefore, the choice of the antigen in autoantibody assays can be challenging. (2) Methods: We collected two independent cohorts with anti-OJ antibodies, one based on a commercial line immunoassay (LIA) (n = 39), the second based on protein immunoprecipitation (IP) (n = 15). Samples were tested using a particle-based multi-analyte technology (PMAT) system that allows for the simultaneous detection of antibodies to various autoantigens. For the detection of anti-OJ antibodies, two different antigens were deployed (KARS, IARS) on PMAT. The reactivity to the two antigens KARS and IARS was analyzed individually and combined in a score (sum of the median fluorescence intensities). (3) Results: In the cohort selection based on LIA, 3/39 (7.7%) samples were positive for anti-KARS and 7/39 (17.9%) for anti-IARS and 14/39 (35.9%) when the two antigens were combined. In contrast, in samples selected by IP the sensitivity of anti-KARS was higher: 6/15 (40.0%) samples were positive for anti-KARS, 4/15 (26.7%) for anti-IARS and 12/15 (80.0%) for the combination of the two antigens. 18/39 (46.2%) of the LIA samples generated a cytoplasmic IIF pattern (compatible with anti-synthetase antibodies), but there was no association with the antibody levels, neither with LIA nor with PMAT. (4) Conclusions: The combination of IARS and KARS might represent a promising approach for the detection of anti-OJ antibodies on a fully automated platform.

Positive Autoantibody Is Associated with Malignancies in Patients with Idiopathic Interstitial Pneumonias

Various autoantibodies are associated with clinical outcomes in patients with idiopathic interstitial pneumonias (IIPs). We retrospectively analyzed the association between autoantibodies and malignancies in IIP patients. Comprehensive analyses of autoantibodies were performed using immunoprecipitation and enzyme-linked immunosorbent assays in 193 consecutive IIP patients. Cancer-related factors were analyzed using logistic regression analysis. In total, 22 of 193 patients (11.4%) with IIP had malignant disease. In univariate analysis, positivity for any autoantibody (odds ratio (OR), 3.1; 95% confidence interval (CI), 1.2-7.7; p = 0.017) and antinuclear antibody titer ≥1:320 (OR, 3.4; CI, 1.2-9.8; p = 0.024) were significantly associated with malignancies. Positive anti-aminoacyl tRNA synthetase (ARS) (OR, 3.7; CI, 0.88-15.5; p = 0.074) and anti-Ro52 antibody (OR, 3.2; CI, 0.93-11.2; p = 0.065) tended to be associated with malignancies. In multivariate analysis, independent risk factors were male sex (OR, 3.7; CI, 1.0-13.5; p = 0.029) and positivity for any autoantibody (OR, 3.9; CI, 1.5-10.1; p = 0.004) in model 1, and male sex (OR, 3.9; CI, 1.0-15.3; p = 0.049), antinuclear antibody titer ≥1:320 (OR, 4.2; CI, 1.4-13.3; p = 0.013), and positivity for anti-ARS antibody (OR, 6.5; CI, 1.2-34.1; p = 0.026) in model 2. Positivity for any autoantibody, antinuclear and anti-ARS antibodies, and male sex were independent risk factors for malignancies in IIP patients. Testing autoantibodies in IIP patients might help the early diagnosis of malignancies.

Clinical Significance of Antinucleolar Antibodies: Biomarkers for Autoimmune Diseases, Malignancies, and others

Nucleolar staining is one of the standard patterns in immunofluorescence antinuclear antibodies (ANA), seen in 5-9% of ANA in various conditions. Antinucleolar antibodies (ANoA) are classified into 3 patterns in the International Consensus on ANA Patterns (ICAP) classification; AC-8 homogeneous pattern, AC-9 clumpy pattern, and AC-10 punctate pattern. Specificities known to show AC-8 include anti-Th/To, -PM-Scl, -nucleophosmin/B23, -nucleolin/C23, -No55, and others. AC-9 is seen by anti-fibrillarin/U3RNP and AC-10 by anti-RNA polymerase I and hUBF/NOR-90. ANoA has been classically known to be associated with scleroderma (SSc) and the characterization of nucleolar antigens identified several autoantigens recognized by SSc autoantibodies. The clinical association of anti-Th/To, PM-Scl, fibrillarin/U3RNP, and RNA polymerase I with SSc or SSc-overlap syndrome is well established, and commercial assays are developed. Anti-hUBF/NOR90, nucleophosmin/B23, and nucleolin/C23 are known for decades and reported in systemic autoimmune rheumatic diseases (SARDs), malignancies, graft versus host disease (GVHD), and others; however, their clinical significance remains to be established.

A cell-based assay for detection of anti-fibrillarin autoantibodies with performance equivalent to immunoprecipitation

Anti-fibrillarin autoantibodies are useful for the diagnosis and prognosis of systemic sclerosis (SSc). Anti-fibrillarin produces a clumpy nucleolar pattern in indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA). Here we develop and validate a reliable cell-based anti-fibrillarin assay (Fibrillarin/CBA) for use in clinical diagnostic laboratories. A TransMembrane Signal was fused to the human fibrillarin gene (TMS-fibrillarin). HEp-2 cells overexpressing transgenic TMS-fibrillarin at the cytoplasmic membrane were used as IFA substrate in the Fibrillarin/CBA. Sixty-two serum samples with nucleolar pattern in the HEp-2 IFA (41 clumpy; 21 homogeneous/punctate) were tested for anti-fibrillarin using Fibrillarin/CBA, immunoprecipitation (IP), line-blot and ELISA. In addition, samples from 106 SSc-patients were evaluated with Fibrillarin/CBA and the results were correlated with disease phenotypes. Thirty-eight of 41 samples with the clumpy nucleolar pattern (92.7%) were positive in the Fibrillarin/CBA, while all 21 samples with other nucleolar patterns were negative. Fibrillarin/CBA results agreed 100% with IP results. Among the 38 Fibrillarin/CBA-positive samples, only 15 (39.5%) and 11 (29%) were positive for anti-fibrillarin in line-blot and ELISA, respectively. Higher frequency of diffuse cutaneous SSc (dcSSc) phenotype (72.7% vs 36.8%; p=0.022), cardiac involvement (36.4% vs 6.5%; p=0.001) and scleroderma renal crisis (18.2% vs 3.3% p = 0.028) was observed in SSc patients with positive compared to negative Fibrillarin/CBA result. Performance of Fibrillarin/CBA in the detection of anti-fibrillarin autoantibodies was comparable to the gold standard IP. Positive Fibrillarin/CBA results correlated with disease phenotypes known to be associated with anti-fibrillarin autoantibodies, underscoring the clinical validation of this novel assay.

Capillary pathology with prominent basement membrane reduplication is the hallmark histopathological feature of scleromyositis

AIMS

To perform ultrastructural and histopathological analysis of muscle biopsies from a large group of systemic sclerosis (SSc) patients, including some with early/mild SSc features, and examine whether capillary pathology differentiates 'scleromyositis' (SM) from other auto-immune myositis (AIM) subsets.

METHODS

Muscle biopsies from a total of 60 SM patients and 43 AIM controls from two independent cohorts were examined by electron microscopy, collagen-4 immunofluorescence (Col4IF) and routine light microscopy.

RESULTS

Ultrastructural examination revealed prominent capillary basement membrane (BM) reduplication (4+ layers in >50% of capillaries) in 65% of SM vs 0% of AIM controls (p<0.001). In SM cases without prominent BM reduplication, capillary dilation was the most distinctive feature, present in 8% of capillaries in SM vs 2% in controls (p=0.001). Accumulation of ensheathed pericyte processes was another characteristic feature of SM and closely correlated with the degree of BM reduplication (r=0.833, p<0.001). On light microscopy, BM marker Col4IF revealed more frequent capillary enlargement in SM than in controls (84% vs 21%, p<0.001). SM cases were classified as non-inflammatory myopathy (36%), non-specific myositis (33%) or immune-mediated necrotizing myopathy (31%), but despite this histopathological heterogeneity, prominent BM reduplication remained a constant finding. In the 16 SM patients with early/mild SSc features, 63% showed prominent BM reduplication.

CONCLUSIONS

These results show that capillary pathology, and in particular prominent capillary BM reduplication, is the hallmark histopathological feature of SM even in patients with early/mild SSc and support the concept of SM as an organ manifestation of SSc and a distinct subset of AIM.

Clinical characteristics of idiopathic interstitial pneumonias with anti-Ro52/tripartite motif-containing 21 antibodies

Antibodies to Ro52/tripartite motif-containing 21 (TRIM21), referred to as anti-Ro52, are found in patients diagnosed with diverse systemic autoimmune rheumatic disease and associated with interstitial lung diseases. However, little is known about the clinical characteristics of anti-Ro52 in patients with idiopathic interstitial pneumonias (IIPs). We aimed to analyze the prevalence, co-existent autoantibodies, and clinical characteristics of anti-Ro52 in patients with IIP. The study enrolled 288 patients diagnosed with IIP. Clinical, laboratory and radiographic findings of IIP patients were compared between anti-Ro52 positives and negatives. Anti-Ro52 (20/288; 6.9%), anti-ARS (18/288; 6.3%), and anti-Ro60/SS-A (16/288; 5.6%) were the most common autoantibodies detected in IIP patients. Among 20 IIP patients who had anti-Ro52, anti-ARS was present in 8 (40%) patients. The criteria for interstitial pneumonia with autoimmune features (IPAF) were significantly better fulfilled by patients with anti-Ro52 than those without (P = 0.001). Meeting serological domain (P < 0.001) and Raynaud’s phenomenon (P = 0.009) were significantly more common in the anti-Ro52-positive patients. Anti-Ro52-positive IIP patients have clinical features consistent with IPAF. Anti-Ro52 may have an important role in detecting the autoimmune phenotype in IIP patients.

P-218 Mitochondria transfer from adipose stem cell ameliorates the development potential of cryopreserved oocytes

Study question

Could autologous adipose stem cell (ASC) mitochondria supplementation restore the post-fertilization development potentialin vitrified-thawed oocytes?

Summary answer

Autologous ASC mitochondria supplementation could rejuvenate the quality of vitrified-thawed oocytes and enhance the embryo’s developmental capacity.

What is known already

Pre- and post-implantation developmental potential of embryos derived from vitrified oocytes are remarkedly lower than those of fresh oocytes. Despite its’ low efficacy, oocyte cryopreservation is becoming prevalent in assisted reproductive technologies to cater the growing demands due to patients' sociological and pathological conditions. Unfavorable effects to mitochondrial membrane potential, mitochondrial structure, ATP production, reactive oxygen species (ROS), meiotic spindle and microfilaments, and Ca2+ ion regulation are reported as detrimental damages in oocytes following the cryopreservation, that adversely affect the development potential. Furthermore, autologous stem cell mitochondria supplementation can rescue the aging-related oocyte mitochondrial damages.

Study design, size, duration

The mature oocytes, autologous ASC, and mitochondria were collected from young mice and analyzed at Osaka City University, Japan. In total, 600 young mouse mature oocytes were occupied in this prospective study.

Participants/materials, setting, methods

Young C57BL/6JJmsmouse (8weeks) mature oocytes that have been pre-vitrified were thawed before the start of the ICSI procedure.ASC specificity and ASC mitochondria function and ultrastructure were pre-analyzed. ASC mitochondria were isolated on the same day and supplemented with intracellular sperm injection (ICSI) and as the control, the mitochondrial buffer was injected. The survival rate, fertilization rate, blastulation, mitochondria function, ROS level in 2 cell embryos, and live birth rates were compared between the 2 groups.

Main results and the role of chance

The ASC mitochondriashowed higher membrane potential compared to the somatic cells and were spherical in shape with low cristae numbers. The survival rate and the fertilization ratewere comparable in both mitochondria supplemented and control groups. However, theASC mitochondria supplementation seemed to havesignificantly improvedthe blastocyst development capacity from 2cell embryos compared to the control group (P &lt; 0.05;56.8% & 38.2%, respectively).And interestingly, a significantly higher ATP level was found in the mitochondria supplemented group’s 2 cell embryos thanin the control group (P &lt; 0.05;905.6pmol & 561.1pmol respectively). And though it was not statistically significant, a higher potential ofgetting live birth was found in the mitochondria supplemented group thanthe control group after 2 cell embryo transfer.

Limitations, reasons for caution

We acknowledge that the absence of compared data with fresh oocytes’ ICSI, the detailed cellular mechanism behind theimprovement of embryo development, and transgenerational safety in offspring developed fromthe mitochondria supplementation werethe limitations of this study.

Wider implications of the findings

With these results, we propose that ASC mitochondria supplementation could rejuvenate the quality of cryopreserved oocytes and enhance the embryo developmental capacity, signifying another possible approach of mitochondrial transplantation therapy.

Trial registration number

not applicable

Significance of Autoantibodies to Ki/SL as Biomarkers for Systemic Lupus Erythematosus and Sicca Syndrome

Anti-Ki/SL antibodies were first described in 1981 and have been associated with systemic lupus erythematosus (SLE) and Sicca syndrome. Despite the long history, very little is known about this autoantibody system, and significant confusion persists. Anti-Ki/SL antibodies target a 32 kDa protein (also known as PSME3, HEL-S-283, PA28ƴ, REGƴ, proteasome activator subunit 3), which is part of the proteasome complex. Depending on the assay used and the cohort studied, the antibodies have been reported in approximately 20% of SLE patients with high disease specificity as compared to non-connective tissue disease controls. The aim of this review is to summarize the history and key publications, and to explore future direction of anti-Ki/SL antibodies.

AB0697 Dramatic reduction of mortality rate by tofacitinib in anti-MDA-5 antibody-positive patients with rapidly progressive interstitial lung disease

Background

Rapidly progressive interstitial lung disease (RP-ILD) is often seen in dermatomyositis patients with anti-melanoma differentiation-associated gene 5 (anti-MDA-5) antibody. They often have a poor prognosis with rapid decline in pulmonary function, leading to respiratory failure (1). Aggressive immunosuppressive therapy has been reported with improved prognosis, however; it may lead to opportunistic infections, including cytomegalovirus (CMV) or Pneumocystis pneumonia (PCP) infection (2, 3).

Objectives

This study aimed to evaluate the effectiveness of tofacitinib (TOF) in combination with CMV and PCP prophylaxis in anti-MDA-5-positive patients.

Methods

Medical records of 17 anti-MDA-5-positive RP-ILD patients enrolled during Mar 2017 to May 2021 were reviewed. RP-ILD was defined by the presence of deteriorated dyspnea, with a decrease in PaO2 levels and emerging radiographic anomalies within 4 weeks without evidence of infection (4). Chest CT was scored using Ichikado score (5). Clinical parameters including ferritin levels, white counts (WBC), Lactate dehydrogenase (LDH) levels, GAP scores (Gender, Age, and Physiology score for idiopathic pulmonary fibrosis) were recorded. Medications included cyclophosphamide (CyP), intravenous immunoglobulin (IVIG), mycophenolic acid derivatives (MPA), rituximab (RTX), and calcineurin inhibitor (CNI). Kaplan-Meier survival analysis and Log-rank test were used to evaluate one-year mortality differences (MedCalc version 19.6). The Ethics Committee approved our study (CE17038B).

Results

Six anti-MDA-5-positive RP-ILD patients were treated with tofacitinib; five had concomitant CMV prophylaxis with valganciclovir (VGCV); 4 had PCP prophylaxis with trimethoprim/sulfamethoxazole (TMP-SMX). Patients’ demographic data are shown in Table 1. The median age, clinical manifestations, laboratory data, and chest CT scores were comparable between tofacitinib and non-tofacitinib groups. Prevalence of MPA use was higher in the non-TOF group. Kaplan-Meier survival analysis (Figure 1) indicated that patients with tofacitinib treatment (p=0.001), valganciclovir (p=0.003), and TMP-SMX (p=0.028) prophylaxis exhibited better 1-year survival rates compared with those without TOF therapy, VGCV, and TMP-SMX prophylaxis.

Table 1.

Clinical characteristics of anti-MDA-5 antibody-positive patients with RP-ILD receiving tofacitinib vs non-tofacitinib treatment.

Tofacitinib (n=6)Non-tofacitinib (n=11)p valueAge (years)58 (42.3-77)57 (50.0-62.0)0.884Female sex, n (%)2 (33.3)6 (54.5)0.620Diabetes mellitus, n (%)0 (0)5 (45.5)0.102Fever, n (%)5 (83.3)10 (90.9)1.000Mechanic’s hands, n (%)4 (66.7)5 (45.5)0.620Ferritin (n=16, ng/ml))2670.9 (719.7-4209.7)1563.5 (967.8-3169.0)0.635WBC (x1000μl)8.7 (6.5-9.9)8.7 (6.0-12.9)0.884LDH (n=16, U/l)367.0 (218.0-557.5)433.0 (331.0-625.3)0.313GAP score5 (2.5-8)5 (2-6)0.808CT score200.0 (124.2-214.2)196.7 (153.3-273.3)0.733TMP-SMX, n (%)4 (66.7)0 (0)0.006**VGCV, n (%)5 (83.3)0 (0)0.001**CyP, n (%)1 (16.7)4 (36.4)0.600IVIG, n (%)1 (16.7)6 (54.5)0.304MPA, n (%)0 (0)7 (63.6)0.035*RTX, n (%)3 (50.0)5 (45.5)1.000CNI, n (%)2 (33.3)6 (54.5)0.620

Continuous variables were expressed as median (inter-quartile range).

*p<0.05, **p<0.01 by Mann–Whitney U test or Fisher’s Exact test.

Figure 1.

Conclusion

The study demonstrated the efficacy of tofacitinib treatment in anti-MDA-5-positive RP-ILD. In addition, CMV and PCP prophylaxis appeared to improve in 1-year survival. Rheumatologists might consider TOF with prophylaxis as an option for anti-MDA-5-positive patients in daily practice.

References

[1]Sato S, et al. Arthritis Rheum 2009;60(7):2193-200.

[2]Sekiguchi A, et al. J Dermatol 2020;47(8):876-81.

[3]Sabbagh SE, et al. Rheumatology 2021;60(2):829-36.

[4]Kurasawa K, et al. Rheumatology 2018;57(12):2114-19.

[5]Ichikado K, et al. Radiology 2006;238(1):321-9.

Acknowledgements

We are grateful to the Biostatistics Task Force staff of Taichung Veterans General Hospital for their assistance in performing the statistical analyses and Tomoko Hasegawa for her technical assistance with the immunoassays. We also thank Dr. Wen-Nan Huang, Dr. Pin-Kuei Fu, Dr. Chia-Wei Hsieh, Dr. Yi-Hsing Chen, and Dr. Der-Yuan Chen for their help on resources and supervision.

Disclosure of Interests

None declared

AB0723 Anti-TIF1-beta autoantibodies in a patient with cancer-associated dermatomyositis

Background

Anti-transcriptional intermediary factor 1-gamma (TIF1-gamma) autoantibodies are strongly linked to cancer-associated dermatomyositis (DM). In addition to anti-TIF1-gamma autoantibodies, autoantibodies to TIF1-alpha and TIF1-beta have been described, often coexisting with TIF1-gamma or other known autoantibodies [1,2]. Thus far, anti-TIF1-beta autoantibodies without other known autoantibodies have been identified in only 3 patients with dermatomyositis, of which none had cancer [1,2].

Objectives

To report on a patient with cancer-associated dermatomyositis and isolated anti-TIF1-beta autoantibodies.

Methods

Serum of a patient with cancer-associated dermatomyositis without known autoantibody specificity was evaluated by immunoprecipitation combined with liquid chromatography-tandem mass spectrometry (IP + LC-MS/MS). Mass spectrometry data were matched against the Uniprot Homo Sapiens database with the Mascot search engine using Proteome Discoverer. Additional immunoprecipitation of radiolabeled cell extract followed by autoradiography were performed. Clinical and laboratory data were retrieved from the electronic health record.

Results

TIF1-beta was identified in the immunoprecipitate of the serum of the patient by IP + LC-MS/MS, but not TIF1-gamma or TIF1-alpha. These results were confirmed by immunoprecipitation of radiolabeled cell extract (Figure 1A). The HEp-2 indirect immunofluorescence assay showed a nuclear fine speckled pattern (AC-4, maximum titre > 1/1280, Figure 1B), which corresponds to the subcellular localization of TIF1-beta [3]. The patient, a 64-year old male, presented with dermatomyositis with classical cutaneous and muscular involvement (max. serum creatine kinase level 370 U/l). A renal cell carcinoma was found during the diagnostic work-up for which a partial nephrectomy was performed. There was a good response of both cutaneous and muscular disease activity to treatment with hydroxychloroquine and methylprednisolone.

Figure 1.

A Immunoprecipitation with 35S-methionine labeled K562 cells with subsequent radiography. C Positive control with anti-TIF1-beta and anti-U1-RNP autoantibodies, 1 anti-TIF1-beta-positive patient (patient here described), 2 negative patient, 3 anti-TIF1-gamma/alpha-positive patient B Nuclear fine speckled pattern on HEp-2 indirect immunofluorescence assay, 40X magnification

Conclusion

Isolated anti-TIF1-beta autoantibodies should be considered in patients with dermatomyositis without known myositis-specific autoantibodies and can be associated with cancer.

References

[1]Fujimoto M, Hamaguchi Y, Kaji K, et al. Myositis-specific anti-155/140 autoantibodies target transcription intermediary factor 1 family proteins. Arthritis Rheum 2012;64:513–22. doi:10.1002/art.33403

[2]Satoh M, Chan JYF, Ross SJ, et al. Autoantibodies to transcription intermediary factor (TIF)1β associated with dermatomyositis. Arthritis Res Ther 2012;14:1–8. doi:10.1186/AR3802/FIGURES/2

[3]Thul PJ, Åkesson L, Wiking M, et al. A subcellular map of the human proteome. Science 2017;356. doi:10.1126/science.aal3321

Disclosure of Interests

Jean-Baptiste Vulsteke: None declared, Petra De Haes: None declared, Minoru Satoh: None declared, Ellen De Langhe: None declared, Xavier Bossuyt Consultant of: Inova Diagnostics, Thermo Fisher Scientific

Autoimmune pulmonary alveolar proteinosis exacerbated by steroid therapy due to misdiagnosis as anti-aminoacyl-tRNA synthetase (ARS) antibody positive- interstitial pneumonia: a case report

BACKGROUND

Anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies are myositis-specific autoantibodies that have been identified in a subset of patients with interstitial pneumonia who do not present with dermatomyositis or polymyositis. Anti-ARS antibody-positive interstitial pneumonia is commonly treated with steroids or immunosuppressive agents and is usually responsive to these therapies. Here, we present in detail a case in which respiratory failure of a patient diagnosed with anti-ARS antibody-positive interstitial pneumonia was exacerbated by treatment with steroids and immunosuppressive agents. Further examination revealed misdiagnosis of this patient and a subsequent diagnosis of autoimmune pulmonary alveolar proteinosis.

CASE PRESENTATION

A 66-year-old man presented to the hospital with dyspnea on exertion, which resulted in the detection of interstitial pneumonia. Serum anti-ARS antibodies were detected; however, there were no other findings suggestive of myositis. Pulmonary alveolar proteinosis (PAP) was suspected based on the marked increase in serum KL-6 and chest computed tomography findings. The bronchoalveolar lavage revealed no milky changes in the lavage fluid. After treatment with steroids and initiation of immunosuppressive agents for anti-ARS antibody-positive interstitial pneumonia, respiratory failure and chest imaging findings showed worsening of the condition. Bronchoscopy was repeated, and milk-like alveolar lavage fluid was collected; serum anti-granulocyte macrophage colony-stimulating factor antibody was identified. Steroids and immunosuppressive agents were gradually tapered and discontinued, and the patient's condition stabilized after repeated alveolar lavage under general anesthesia.

CONCLUSION

Due to similar presentation, PAP can be misdiagnosed as interstitial pneumonia. If pulmonary lesions due to interstitial pneumonia are exacerbated by immunosuppressive treatment, physicians should reconsider the diagnosis and include PAP in the differential diagnosis.

Antigen Reactivity and Clinical Significance of Autoantibodies Directed Against the Pyruvate Dehydrogenase Antigen Complex in Patients With Connective Tissue Disease

Introduction

Antimitochondrial antibodies (AMAs) are the hallmark of primary biliary cholangitis (PBC) but can be identified also in patients with connective tissue disease, namely, systemic sclerosis (SSc). Protein immunoprecipitation (IP) and IP-Western blot (WB) can be used to confirm AMA positivity directed at the pyruvate dehydrogenase complex (PDC) subunits E1α, E1β, E2/E3, and E3BP in patients showing a cytoplasmic reticular pattern at indirect immunofluorescence when performed in a screening setting before the onset of overt cholestasis in rheumatic patients.

Patients and Methods

We studied sera from 285 patients affected by connective tissue disease [SSc, n = 144; dermato/polymyositis (DM/PM), n = 56; and undifferentiated connective tissue disease (UCTD), n = 85] by indirect immunofluorescence (IIF), protein-IP, and IP-WB to identify specific PDC subunits recognized by AMA.

Results

Twenty percent (57/285) of sera from patients with connective tissue disease had a cytoplasmic reticular pattern at IIF, and in 77% (44/57, including 20 SSc, 12 PM/DM, and 12 UCTD) of these, we detected different titers of autoantibodies against the PDC subunits, specifically against PDC-E2. Among these sera, 4 (9%) tested positive for anti-E1α, 15 (34%) for anti-E1β, and 16 (36%) for anti-E3BP. Four of the 20 AMA-positive SSc cases (20%) had been already diagnosed with PBC, and all were positive for autoantibodies against the subunits PDC-E2, E3, and E3BP.

Conclusions

Using IIF and IP, we confirm that autoantibodies against the PDC components are detected in rheumatic patients with PBC or without liver dysfunction. In view of the strong predictive value of AMA for PBC, a strict follow-up of these latter patients is warranted for an early diagnosis of the disease.

Genome-wide detection of non-additive quantitative trait loci for semen production traits in beef and dairy bulls

Semen production traits are important aspects of bull fertility, because semen quantity leads to direct profits for artificial insemination centres, and semen quality is associated with the probability of achieving a pregnancy. Most genome-wide association studies (GWASs) for semen production traits have assumed that each quantitative trait locus (QTL) has an additive effect. However, GWASs that account for non-additive effects are also important in fitness traits, such as bull fertility. Here, we performed a GWAS using models that accounted for additive and non-additive effects to evaluate the importance of non-additive effects on five semen production traits in beef and dairy bulls. A total of 65 463 records for 615 Japanese Black bulls (JB) and 50 734 records for 873 Holstein bulls (HOL), which were previously genotyped using the Illumina BovineSNP50 BeadChip, were used to estimate genetic parameters and perform GWAS. The heritability estimates were low (ranged from 0.11 to 0.23), and the repeatability estimates were low to moderate (ranged from 0.28 to 0.45) in both breeds. The estimated repeatability was approximately twice as high as the estimated heritability for all traits. In this study, only one significant region with an additive effect was detected in each breed, but multiple significant regions with non-additive effects were detected for each breed. In particular, the region at approximately 64 Mbp on Bos taurus autosome 17 had the highest significant non-additive effect on four semen production traits in HOL. The rs41843851 single nucleotide polymorphism (SNP) in the region had a much lower P-value for the non-additive effect (P-value = 1.1 × 10^-31) than for the additive effect (P-value = 1.1 × 10^-8) in sperm motility. The AA and AB genotypes on the SNP had a higher phenotype than the BB genotype in HOL, and there was no bull with the BB genotype in JB. Our results showed that non-additive QTLs affect semen production traits, and a novel QTL accounting for non-additive effects could be detected by GWAS. This study provides new insights into non-additive QTLs that affect fitness traits, such as semen production traits in beef and dairy bulls.

Heritability and genetic correlation estimates of semen production traits with litter traits and pork production traits in purebred Duroc pigs

We estimated heritabilities of semen production traits and their genetic correlations with litter traits and pork production traits in purebred Duroc pigs. Semen production traits were semen volume, sperm concentration, proportion of morphologically normal sperms, total number of sperm, and total number of morphologically normal sperm. Litter traits at farrowing were total number born, number born alive, number stillborn, total litter weight at birth, mean litter weight at birth, and piglet survival rate at birth. Litter traits at weaning were litter size at weaning, total litter weight at weaning, mean litter weight at weaning, and piglet survival rate from birth to weaning. Pork production traits were average daily gain, backfat thickness, and loin muscle area. We analyzed 45,913 semen collection records of 896 boars, 6,950 farrowing performance records of 1,400 sows, 2,237 weaning performance records of 586 sows, and individual growth performance records of 9,550 animals measured at approximately 5 mo of age. Heritabilities were estimated using a single-trait animal model. Genetic correlations were estimated using a 2-trait animal model. Estimated heritabilities of semen production traits ranged from 0.20 for sperm concentration to 0.29 for semen volume and were equal to or higher than those of litter traits, ranging from 0.06 for number stillborn and piglet survival rate at birth to 0.25 for mean litter weight at birth, but lower than those of pork production traits, ranging from 0.50 for average daily gain to 0.63 for backfat thickness. In many cases, the absolute values of estimated genetic correlations between semen production traits and other traits were smaller than 0.3. These estimated genetic parameters provide useful information for establishing a comprehensive pig breeding scheme.

Genetic parameters of 5 semen production traits, 10 litter traits, and 3 pork production traits in purebred Duroc pigs was estimated. Heritabilities of semen production traits ranged from 0.20 for sperm concentration to 0.29 for semen volume and were equal to or higher than those of litter traits, ranging from 0.06 for number stillborn and piglet survival rate at birth to 0.25 for mean litter weight at birth, but lower than those of pork production traits, ranging from 0.50 for average daily gain to 0.63 for backfat thickness. In many cases, the absolute values of genetic correlations between semen production traits and other traits were smaller than 0.3. These estimated genetic parameters provide useful information for establishing a comprehensive pig breeding scheme.

Myositis with prominent B-cell aggregates causing shrinking lung syndrome in systemic lupus erythematosus: a case report

Background

Shrinking lung syndrome (SLS) is a rare manifestation of systemic lupus erythematosus (SLE) characterized by decreased lung volumes and diaphragmatic weakness in a dyspneic patient. Chest wall dysfunction secondary to pleuritis is the most commonly proposed cause. In this case report, we highlight a new potential mechanism of SLS in SLE, namely diaphragmatic weakness associated with myositis with CD20 positive B-cell aggregates.

Case presentation

A 51-year-old Caucasian woman was diagnosed with SLE and secondary Sjögren’s syndrome based on a history of pleuritis, constrictive pericarditis, polyarthritis, photosensitivity, alopecia, oral ulcers, xerophthalmia and xerostomia. Serologies were significant for positive antinuclear antibodies, anti-SSA, lupus anticoagulant and anti-cardiolopin. Blood work revealed a low C3 and C4, lymphopenia and thrombocytopenia. She was treated with with low-dose prednisone and remained in remission with oral hydroxychloroquine. Seven years later, she developed mild proximal muscle weakness and exertional dyspnea. Pulmonary function testing revealed a restrictive pattern with small lung volumes. Pulmonary imaging showed elevation of the right hemidiaphragm without evidence of interstitial lung disease. Diaphragmatic ultrasound was suggestive of profound diaphragmatic weakness and dysfunction. Based on these findings, a diagnosis of SLS was made. Her proximal muscle weakness was investigated, and creatine kinase (CK) levels were normal. Electromyography revealed fibrillation potentials in the biceps, iliopsoas, cervical and thoracic paraspinal muscles, and complex repetitive discharges in cervical paraspinal muscles. Biceps muscle biopsy revealed dense endomysial lymphocytic aggregates rich in CD20 positive B cells, perimysial fragmentation with plasma cell-rich perivascular infiltrates, diffuse sarcolemmal upregulation of class I MHC, perifascicular upregulation of class II MHC, and focal sarcolemmal deposition of C5b-9. Treatment with prednisone 15 mg/day and oral mycophenolate mofetil 2 g/day was initiated. Shortness of breath and proximal muscle weakness improved significantly.

Conclusion

Diaphragmatic weakness was the inaugural manifestation of myositis in this patient with SLE. The spectrum of myologic manifestations of myositis with prominent CD20 positive B-cell aggregates in SLE now includes normal CK levels and diaphragmatic involvement, in association with SLS.

The International Consensus on ANA Patterns (ICAP) in 2021-The 6th Workshop and Current Perspectives

The establishment of the International Consensus on ANA Patterns (ICAP) in 2014-2015 was welcomed by members of the medical community as a significant improvement in guiding harmonization of ANA test interpretation and reporting. In the subsequent years, several itinerant meetings and continuous interaction with the community contributed to disseminate the ICAP harmonization on the immunofluorescence patterns observed in the indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) and to promote progressive improvement in the classification of HEp-2 IFA patterns. The 6th ICAP Workshop was held in person on September 6, 2021 as a satellite meeting of the 15th Dresden Symposium on Autoantibodies. This article summarizes the major discussions at the meeting as well as outlining the current plans for the ICAP committee.

Fibronectin plays a major role in hypoxia-induced lenvatinib resistance in hepatocellular carcinoma PLC/PRF/5 cells

Resistance to lenvatinib mesylate (LEN), a systemic chemotherapy that can be administered orally, has been a major issue for treatment of hepatocellular carcinoma (HCC). Although HCC is the tumor that most exhibits intratumoral hypoxia, which has been shown to be involved in the development of treatment resistance, there are no reports of LEN resistance in HCC treatment under hypoxia. The purpose of our study was to elucidate the mechanism of treatment resistance to LEN under hypoxia using HCC cell lines. We confirmed LEN resistance under hypoxic conditions in HCC cell lines. There was a significant increase in the IC₅₀ value of PLC/PRF/5 cells from 13.0±0.8 μM in normoxia to 21.3±1.1 μM in hypoxia, but in HepG2 cells, the increase was not significant. To elucidate the LEN resistance mechanism of PLC/PRF/5 cells under hypoxia, we performed microarray analysis and extracted genes that are thought to be related to this mechanism. Furthermore, in-silico analysis confirmed significant changes in the extracellular matrix, and among them, FN1 encoding fibronectin was determined as the hub of the gene cluster. The expression of fibronectin in PLC/PRF/5 cells examined with immunofluorescence staining was significantly elevated in and outside of cells under hypoxia, and tended to decrease when cells were exposed to LEN under normoxia. Furthermore, the fibronectin concentration in the culture solution of PLC/PRF/5 cells examined by ELISA was 2.3 times higher under hypoxia than under normoxia under LEN(-) conditions, and 1.6 times higher under hypoxia than under normoxia under LEN(+) conditions. It is assumed that in PLC/PRF/5 cells, fibronectin is probably suppressed as an indirect effect of LEN under normoxia, but transcription factors such as HIF-1α are induced under hypoxia, thus enhancing the production of fibronectin and attenuating the effect of LEN, resulting in drug resistance. This behavior of fibronectin with LEN exposure under hypoxia is probably specific to PLC/PRF/5 cells. Further studies should verify the combined effective inhibition of fibronectin and the MAPK pathway as a promising therapeutic strategy to enhance the value of LEN in HCC treatment.

Development of Rheumatoid Arthritis During Anti-Interleukin-5 Therapy in a Patient with Refractory Chronic Eosinophilic Pneumonia

Purpose

To report the case of a patient with refractory chronic eosinophilic pneumonia who developed rheumatoid arthritis during anti-interleukin (IL)-5 therapy.

Case Report

The case of a 66-year-old male ex-smoker with allergic rhinitis who had dyspnea and chronic cough for 6 months and who was ultimately diagnosed with chronic eosinophilic pneumonia is reported. Long-term corticosteroid therapy was necessary due to recurrence of the chronic eosinophilic pneumonia during tapering of the corticosteroid. As a steroid sparing strategy, mepolizumab was initiated, and the steroid was tapered gradually. When the dose of prednisolone was 2 mg/day, he developed polyarthralgia. Mepolizumab was changed to benralizumab considering the possibility that arthralgia was a side effect of mepolizumab; however, the arthralgia continued and he was ultimately diagnosed with rheumatoid arthritis. Methotrexate was initiated and his arthritis improved. Thereafter, benralizumab was discontinued after 5 injections, and he subsequently required neither systemic corticosteroids nor biologics.

Conclusion

The present case may suggest that suppression of IL-5 induces rheumatoid arthritis in certain patients; however, it is also possible that initial steroid therapy improved subclinical RA and made it remain undiagnosed, and the parallel OCS tapering during IL-5 therapy could have contributed to unveil the underlying RA. Further studies are required to establish guidelines on the optimum use of anti-IL-5 therapy and to understand the interactions between chronic eosinophilic pneumonia, anti-IL-5 therapy, tapering of corticosteroid and development of rheumatoid arthritis.

Estimation of genetic parameter for feed efficiency and resilience traits in three pig breeds

Recently, automatic feeders have become popular for collecting daily feed intake data in the pig industry, making it possible to evaluate genetic effects on feed efficiency and resilience traits, expressed as day-to-day fluctuations in feeding records. This study aimed to understand the influence of genetic factors on feed efficiency traits, including residual intake and BW gain (RIG), and resilience traits, as well as to compare the differences in genetic parameter estimates among three purebred pig breeds. A total of 6 103 pigs from three breeds (Large White: 1 193 pigs, Landrace: 3 010 pigs, and Duroc: 1 900 pigs) were raised in a specific pathogen-free environment. The growth and feed intake records during the testing period were obtained using automatic feeders, and the average daily gain (ADG) and average feed intake (AFI) were calculated. Feed conversion ratio (FCR), residual feed intake (RFI), residual gain, and RIG were calculated as feed efficiency traits, and the log-transformed variance of deviation for the daily feed intake (LnVar_FI), daily occupation time (LnVar_OC), and the daily number of visits to the feeder (LnVar_VT) was calculated as resilience traits. After estimating the genetic parameters for each breed, a meta-analysis was performed to obtain the weighted mean of heritability estimates (h_m²) and genetic correlation estimates (GC_m) for the three breeds. The h_m² were moderate and ranged from 0.31 to 0.39 for feed efficiency traits and 0.31 to 0.40 for resilience traits, and there were no significant differences in heritability estimates among the three breeds except for AFI, RFI, and RIG. For feed efficiency traits, the FCR and RIG showed favourably moderate GC_m with AFI (0.29 and -0.33, respectively) and ADG (-0.39 and 0.31, respectively). For resilience traits, the LnVar_FI and LnVar_VT showed favourably low to moderate GC_m with FCR (0.33 and 0.28, respectively) and RIG (-0.37 and 0.28, respectively), and there were no genetic relationships of LnVar_OC with FCR and RIG (the absolute value of GC_m was 0.01). There was no significant difference in the genetic correlation estimates among the three breeds for feed efficiency and resilience traits. Our results suggest that feed efficiency and resilience traits were heritable, and resilience traits showed favourable or no genetic correlation with feed efficiency traits. In addition, the influence of genetic factors on feed efficiency and resilience traits could be the same among breeds.

The DNA co-vaccination using Sm antigen and IL-10 as prophylactic experimental therapy ameliorates nephritis in a model of lupus induced by pristane

Introduction

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies such as anti-Sm. Studies in patients with SLE and murine models of lupus reveal that the most critical anti-Sm autoantibodies are predominantly direct against D1_(83–119), D2, and B´/B epitopes.

Objectives

The present study aimed to analyze the induction of antigen-specific tolerance after prophylactic immunization with a DNA vaccine encoding the epitopes: D1_83-119, D2, B´/B, and B´/B_COOH in co-vaccination with IFN-γ or IL-10 in a murine model of lupus induced by pristane.

Material and methods

To obtain endotoxin-free DNA vaccines, direct cloning techniques using pcDNA were performed: D1_83-119, D2, B´/B, B´/B_COOH, IFN-γ, or IL-10. Lupus was induced by 0.5 mL of pristane via intraperitoneal in BALB/c female mice. Immunoprecipitation with K562 cells was metabolically labeled with ³⁵S and ELISA to detect serum antibodies or mice IgG1, IgG2a isotypes. ELISA determined IL-10 and IFN-γ from splenocytes supernatants. Proteinuria was assessed monthly, and lupus nephritis was evaluated by immunofluorescence, and electron microscopy.

Results

The prophylactic co-vaccination with D2/IL-10 reduced the expression of kidney damage observed by electron microscopy, direct immunofluorescence, and H & E, along with reduced level of anti-nRNP/Sm antibodies (P = 0.048).

Conclusion

The prophylactic co-vaccination of IL-10 with D2 in pristane-induced lupus ameliorates the renal damage maybe by acting as prophylactic DNA tolerizing therapy.

Clustering of health behaviours and association with sociodemographic factors among adults in Japan

Background

Health behaviours (HBs) commonly co-occur, acting synergistically. Little is known about the clustering of HBs in the Japanese population. Therefore, this study aimed to investigate the clusters of HB patterns and sociodemographic factors related to the clusters in the Japanese population.

Methods

Data used in this study was obtained from the Japanese and Keio Household Panel Surveys. The responses of 1,554 questionnaires (aged 27 − 65 years) were analysed. The surveys probed HBs (alcohol consumption, smoking, vegetable and fruit consumption, breakfast consumption habits, and physical activity) and sociodemographic characteristics. Latent class analysis was used to identify the clusters, and latent regression was used to investigate sociodemographic characteristics related to the clusters by gender.

Results

Two HB clusters were identified: ‘inactive, moderately healthy' and ‘inactive, high alcohol consumption, poor nutrition'. Age in the 60s indicated significantly higher odds ratios (ORs) of the ‘inactive, moderately healthy' cluster in men and women [OR = 1.820, 95% confidence interval (CI)=1.109 − 2.985, p = 0.018; OR = 3.865, CI = 1.830 − 8.163, p = 0.000]. In men, living with families and higher education levels indicated significantly higher ORs of the ‘inactive, moderately healthy' cluster (OR = 1.812, CI = 1.078 − 3.047, p = 0.025; OR = 2.236, CI = 1.698 − 2.943, p = 0.000). In women, being married, higher socioeconomic status, and higher education levels indicated significantly higher ORs of the ‘inactive, moderately healthy' cluster (OR = 2.097, CI = 1.309 − 3.359, p = 0.002; OR = 2.068, CI = 1.092 − 3.917, p = 0.026; OR = 2.516, CI = 1.563 − 4.051, p = 0.000).

Conclusions

Policymakers must recognise HB clusters unique to Japanese adults and have to build effective strategies based on understanding gender differences and similarities in sociodemographic factors associated with HB clusters.

Key messages

Interventions for multiple HB simultaneously should be designed and developed. Health behavior patterns have to be clarified for targeting population when interventions are built.

How to report the antinuclear antibodies (anti-cell antibodies) test on HEp-2 cells: guidelines from the ICAP initiative

Results of the anti-nuclear antibodies-indirect immunofluorescence assay (anti-cell antibodies test) on HEp-2 cell substrates should be communicated to clinicians in a standardized way, adding value to laboratory findings and helping with critical clinical decisions. This paper proposes a test report based on the practices informed by 118 laboratories in 68 countries, with recommendations from the International Consensus on ANA Patterns (ICAP) group. Major focus is placed on the report format containing endpoint titers, immunofluorescence patterns together with anti-cell (AC) nomenclature, remarks on follow-up or reflex testing, and possible other autoantibody associations. ISO 15,189 directives were integrated into the test report. Special situations addressed include serum screening dilutions and endpoint titers, relevance of immunofluorescence patterns with special attention to cytoplasmic patterns, mixed and compound patterns, and how to report different titers corresponding to multiple patterns or autoantibodies in the same sample. This paper suggests a subtitle for the HEp-2-IIFA, namely anti-cell antibodies test, which could gradually substitute the original outdated ANA nomenclature. This ICAP pro forma report represents a further step in harmonizing the way relevant clinical information could be provided by laboratories.

A Japanese Patient with Anti-PM/Scl and Centromere Antibody-Positive Scleroderma-Amyopathic Dermatomyositis Overlap Syndrome Who Developed Renal Crisis

Anti-PM/Scl antibodies are associated with the overlap syndrome of systemic sclerosis and dermatomyositis/polymyositis (SSc-DM/PM), and are found in 50% of SSc-DM/PM cases in Europe and the United States, whereas they are rare in Japan. We report a case of an 80-year-old Japanese female with SSc-amyopathic dermatomyositis (ADM) overlap syndrome, who developed scleroderma renal crisis (SRC), a complication of SSc. She had positive antinuclear antibodies in a discrete-speckled and nucleolar pattern and anticentromere antibodies and anti-PM/Scl antibodies were confirmed by ELISA and immunoprecipitation, respectively. The incidence rate of SRC in SSc patients varies significantly depending on the specificity of autoantibodies, with the highest incidence of ~50% in anti-RNA polymerase III antibody positive patients, followed by ~10% in anti-PM/Scl and lower incidence of 0.45% in anticentromere antibody-positive cases. Anti-PM/Scl antibodies are uncommon in Japanese patients presumably due to its strong association with certain HLA haplotype that is rare in Japanese. Clinical significance of anti-PM/Scl antibodies in Japanese patients will need to be clarified with accumulation of cases in future studies.

A case of recurrent acute febrile neutrophilic dermatosis in a patient with idiopathic cytopenia of undetermined significance

This is the first report of recurrent acute febrile neutrophilic dermatosis in a patient with idiopathic cytopenia of undetermined significance. The patient progressed to acute myeloid leukaemia 4 months after onset.

Recognising the spectrum of scleromyositis: HEp-2 ANA patterns allow identification of a novel clinical subset with anti-SMN autoantibodies

Objective

To describe systemic sclerosis (SSc) with myopathy in patients without classic SSc-specific and SSc-overlap autoantibodies (aAbs), referred to as seronegative scleromyositis.

Methods

Twenty patients with seronegative scleromyositis diagnosed by expert opinion were analysed retrospectively for SSc features at myositis diagnosis and follow-up, and stratified based on HEp-2 nuclear patterns by indirect immunofluorescence (IIF) according to International Consensus of Autoantibody Patterns. Specificities were analysed by protein A−assisted immunoprecipitation. Myopathy was considered an organ involvement of SSc.

Results

SSc sine scleroderma was a frequent presentation (45%) at myositis diagnosis. Myositis was the most common first non-Raynaud manifestation of SSc (55%). Lower oesophagal dysmotility was present in 10 of 11 (91%) investigated patients. At follow-up, 80% of the patients met the American College of Rheumatology/EULAR SSc classification criteria. Two-thirds of patients had a positive HEp-2 IIF nuclear pattern (all with titers ≥1/320), defining three novel scleromyositis subsets. First, antinuclear antibody (ANA)-negative scleromyositis was associated with interstitial lung disease (ILD) and renal crisis. Second, a speckled pattern uncovered multiple rare SSc-specific aAbs. Third, the nuclear dots pattern was associated with aAbs to survival of motor neuron (SMN) complex and a novel scleromyositis subset characteriszed by calcinosis but infrequent ILD and renal crisis.

Conclusions

SSc skin involvement is often absent in early seronegative scleromyositis. ANA positivity, Raynaud phenomenon, SSc-type capillaroscopy and/or lower oesophagal dysmotility may be clues for scleromyositis. Using HEp-2 IIF patterns, three novel clinicoserological subsets of scleromyositis emerged, notably (1) ANA-negative, (2) ANA-positive with a speckled pattern and (3) ANA-positive with nuclear dots and anti-SMN aAbs.

Autoantibody profiles delineate distinct subsets of scleromyositis

OBJECTIVE

Scleromyositis remains incompletely characterized owing in part to its heterogeneity. The purpose of this study was to explore the role of autoantibody profiles to define subsets of scleromyositis.

METHODS

Subjects with scleromyositis from a prospective cohort were divided into 3 groups based on autoantibody profiles: subjects with SSc-specific autoantibodies (anti-centromere, -topoisomerase 1, -RNA polymerase III, -Th/To, -fibrillarin), subjects with SSc-overlap autoantibodies (anti-PM/Scl, -U1RNP, -Ku), and subjects without SSc-related autoantibodies. Clinical features, laboratory tests, and histopathological findings were retrieved and compared between groups.

RESULTS

Of 42 scleromyositis subjects (79% female, mean age at diagnosis 55 years, mean disease duration 3.5 years), 8 (19%) subjects had SSc-specific autoantibodies, 14 (33%) SSc-overlap autoantibodies and 20 (48%) had no SSc-related autoantibodies. One-third had no skin involvement, a finding more frequent in the SSc-overlap subjects and those without SSc-related autoantibodies. Proximal and distal weakness was common and head drop/bent spine was found in 50% of the SSc-specific and 35% of the subjects without SSc-related autoantibodies. Of note, the group without SSc-related autoantibodies had the only cases of severe cardiac systolic dysfunction (n = 1) and scleroderma renal crisis (n = 1), as well as 3 out of the 4 cancers and 3 out of the 4 deaths.

CONCLUSION

In this carefully phenotyped series of scleromyositis subjects, absence of SSc-related autoantibodies was common and associated with distinct features and poor prognosis. Future studies are needed to validate these results and possibly identify novel autoantibodies or other biomarkers associated with scleromyositis.

Autoantibody Discovery, Assay Development and Adoption: Death Valley, the Sea of Survival and Beyond

Dating to the discovery of the Lupus Erythematosus (LE) cell in 1948, there has been a dramatic growth in the discovery of unique autoantibodies and their cognate targets, all of which has led to the availability and use of autoantibody testing for a broad spectrum of autoimmune diseases. Most studies of the sensitivity, specificity, commutability, and harmonization of autoantibody testing have focused on widely available, commercially developed and agency-certified autoantibody kits. However, this is only a small part of the spectrum of autoantibody tests that are provided through laboratories world-wide. This manuscript will review the wider spectrum of testing by exploring the innovation pathway that begins with autoantibody discovery followed by assessment of clinical relevance, accuracy, validation, and then consideration of regulatory requirements as an approved diagnostic test. Some tests are offered as "Research Use Only (RUO)", some as "Laboratory Developed Tests (LDT)", some enter Health Technology Assessment (HTA) pathways, while others are relegated to a "death valley" of autoantibody discovery and become "orphan" autoantibodies. Those that achieve regulatory approval are further threatened by the business world's "Darwinian Sea of Survival". As one example of the trappings of autoantibody progression or failure, it is reported that more than 200 different autoantibodies have been described in systemic lupus erythematosus (SLE), a small handful (~10%) of these have achieved regulatory approval and are widely available as commercial diagnostic kits, while a few others may be available as RUO or LDT assays. However, the vast majority (90%) are orphaned and languish in an autoantibody 'death valley'. This review proposes that it is important to keep an inventory of these "orphan autoantibodies" in 'death valley' because, with the increasing availability of multi-analyte arrays and artificial intelligence (MAAI), some can be rescued to achieve a useful role in clinical diagnostic especially in light of patient stratification and precision medicine.

Histopathological features of systemic sclerosis-associated myopathy: A scoping review

BACKGROUND

Scleromyositis (SM) is an emerging subset of myositis associated with features of systemic sclerosis (SSc) but it is currently not recognized as a distinct histopathological subset by the European NeuroMuscular Center (ENMC). Our aim was to review studies reporting muscle biopsies from SSc patients with myositis and to identify unique histopathological features of SM.

METHODS

A scoping review was conducted and included all studies reporting histopathological findings in SSc patients with myositis searching the following databases: PubMed, MEDLINE, EMBASE, CINAHL and EBM-Reviews. Clinical, serological, and histopathological data were extracted using a standardized protocol.

RESULTS

Out of 371 citations, 77 studies that included 559 muscle biopsies were extracted. Fifty-seven percent (n = 227/400) had inflammatory infiltrates, predominantly T cells, which were endomysial (49%), perimysial (42%) and perivascular (41%). Few studies (18%, n = 8/44) evaluated the presence of B-cells. Myofiber atrophy was present in 48% (n = 104/218) of biopsies, and was predominantly perifascicular in 19% (n = 6/31), with necrosis reported in 56% (n = 162/290) of cases. Sarcolemmal MHC-I upregulation was found in 72% (n = 64/89) of biopsies. Non-specified C5b-9 deposition was described in 39% of muscle biopsies (n = 28/72). Neurogenic features were present in 23% (n = 44/191); endomysial fibrosis was reported in 35% (n = 120/340); and rimmed vacuoles were observed in 32% (n = 11/34) of biopsies. Capillaropathy, such as capillary dropout and/or ultrastructural endothelial abnormalities, was reported in 33% (n = 43/129) of cases. Reported ENMC categories were mainly polymyositis (21%), non-specific myositis (19%), immune-mediated necrotizing myopathy (16%), and dermatomyositis (8%). Histopathological features were analyzed according to serological subtypes in 28 studies, including anti-PM-Scl (n = 48), -Ku (n = 23) and -U1RNP (n = 90). Most of these biopsies demonstrated inflammatory infiltrates (range 49-85%) as well as MHC-I expression (range 63-81%). Necrosis was associated with anti-Ku (85%) and anti-U1RNP (73%), while anti-Ku was also associated with neurogenic features and rimmed vacuoles in 57% and 25% of cases, respectively.

CONCLUSION

Our review suggests that SM is characterized by heterogeneous pathological features using definitions included in current histopathological criteria. Whether a distinct histopathological signature exists in SM remains to be determined. SSc-specific and SSc-associated autoantibodies may help define more homogeneous histopathological subsets.

Presence of anti-TIF-1γ, anti-Ro52, anti-SSA/Ro60 and anti-Su/Ago2 antibodies in breast cancer: a cross-sectional study

OBJECTIVES

The presence of myositis-specific antibodies (MSA), was recently reported in healthy individuals, cancer patients without myopathy and paraneoplastic rheumatic syndromes. We sought to analyze the frequency of MSA, myositis-associated antibodies (MAA) and autoantibodies related to systemic autoimmune rheumatic diseases (SARD) in breast cancer patients.

METHODS

One hundred fifty-two breast cancer patients were enrolled in a cross-sectional study. Clinical information was collected, and autoantibodies tested by immunoprecipitation of an ³⁵S-methionine-labeled K562 cell extract, enzyme-linked immunosorbent assay (ELISA) and Western blot when indicated. All statistical tests were performed using the software statistical package for the social science (SPSS) ver. 19.0 (IBM Inc., NYSE, USA).

RESULTS

Autoantibodies associated with SARD: anti-52 kD ribonucleoprotein/tripartite motif-containing 21 (anti-Ro52/TRIM21) was found in 5.9% (9/152), anti-Sjögren syndrome-related antigen A/60 kD ribonucleoprotein antibody (anti-SSA/Ro60) in 3.9% (6/152) and anti-Su antigen/Argonaute 2 antibody (anti-Su/Ago2) in 2.6% (4/152). Meanwhile, anti-transcription intermediary factor-1γ (anti-TIF-1γ, p155/140) antibody was positive in 2 cases and anti-polymyositis/scleroderma antibody was detected in one case. As a whole, 14.47% (22/152) of breast cancer patients showed autoantibodies associated with SARD. These specific autoantibodies were not associated with the presence of rheumatic diseases except one rheumatoid arthritis patient positive for anti-Ro52/TRIM21.

CONCLUSIONS

Autoantibodies to TIF-1γ were found in two patients with breast cancer without dermatomyositis (DM). More common specificities were autoantibodies anti-SSA/Ro60, anti-Ro52/TRIM21 and anti-Su/Ago2. More studies are needed in order to establish the biological meaning of the presence of SARD-associated autoantibodies in breast cancer.

Influenza A (H3N2) infection followed by anti-signal recognition particle antibody-positive necrotizing myopathy: A case report

A 60-year-old Japanese woman presented with subacute progressive muscle pain and weakness in her proximal extremities. She was diagnosed with influenza A (H3N2) infection a week before the onset of muscle pain. At the time of admission, she exhibited weakness in the proximal muscles of the upper and lower limbs, elevated serum liver enzymes and creatinine kinase, and myoglobinuria. She did not manifest renal failure and cardiac abnormalities, indicating myocarditis. Electromyography revealed myogenic changes, and magnetic resonance imaging of the upper limb showed abnormal signal intensities in the muscles, suggestive of myopathy. Muscle biopsy of the biceps revealed numerous necrotic regeneration fibers and mild inflammatory cell infiltration, suggesting immune-mediated necrotizing myopathy (IMNM). Necrotized muscle cells were positive for human influenza A (H3N2). Autoantibody analysis showed the presence of antibodies against the signal recognition particle (SRP), and the patient was diagnosed with anti-SRP-associated IMNM. She was resistant to intravenous methylprednisolone pulse therapy but recovered after administration of oral systemic corticosteroids and immunoglobulins. We speculate that the influenza A (H3N2) infection might have triggered her IMNM. Thus, IMNM should be considered as a differential diagnosis in patients with proximal muscle weakness that persists after viral infections.