[How can we diagnose and better understand inflammatory myopathies? The usefulness of auto-antibodies]

Association of anti-NXP2 antibody with clinical characteristics and outcomes in adult dermatomyositis: results from clinical applications based on a myositis-specific antibody

OBJECTIVES

The aim was to study and compare the clinical manifestations, auxiliary examinations, and therapeutic responses in patients with different myositis-specific antibody (MSA) types.

METHOD

We retrospectively investigated the medical records of 143 hospitalized dermatomyositis patients, all of whom were tested for MSAs, and performed follow-up. Patients were divided into groups with and without anti-nuclear matrix protein 2 (NXP2) antibodies (17 vs 126 patients). Demographic, clinical manifestation (occurring at any time during the disease course), imaging, laboratory, treatment response, and survival data were collected for statistical analyses.

RESULTS

Adult dermatomyositis patients with anti-NXP2 antibodies were more prone to dysphagia (P<0.001), had higher levels of muscle injury markers (CK peak, P=0.007; CK peak>1000 IU/L, P<0.001; CK-MB, P=0.002), were younger at onset (P=0.008), and were less likely to present with interstitial lung disease (P=0.016) than the anti-NXP2 antibody-negative subgroup. Multivariable logistic regression analysis showed that onset age (OR=0.96 CI 95%: 0.924-0.999, P=0.043) and dysphagia (OR=7.088, CI 95%: 1.824-27.536, P=0.005) were independent risk factors for anti-NXP2 antibody positivity. Kaplan-Meier survival analysis did not reveal that dermatomyositis patients with anti-NXP2 antibodies have a relatively worse prognosis. However, the disease course was more frequently polycyclic, and 68.75% of patients had a relapsing-remitting disease course. More than half (52.94%) of those who showed no response to treatment used at least 3 disease-modifying antirheumatic drugs.

CONCLUSIONS

We show the important clinical features of and risk factors for this unique antibody-mediated form of dermatomyositis. Although these patients had a relatively low mortality rate, they were prone to recurrence, and treatment was challenging. Key points • The clinical features and risk factors for adult dermatomyositis patients with anti-NXP2 antibodies. • The impact of anti-NXP2 antibody on survival outcomes.

Antisynthetase Syndrome and Autoantibodies: A Literature Review and Report of 4 Cases

Case series

Patient: Female, 25 • Female, 39 • Male, 27 • Female, 42

Final Diagnosis: Antisynthetase syndrome

Symptoms: Arthralgia • dyspnea • muscle weakness

Medication: —

Clinical Procedure: Immunosuppressive therapy

Specialty: Rheumatology

Bench to bedside review of myositis autoantibodies

Idiopathic inflammatory myopathies represent a heterogeneous group of autoimmune diseases with systemic involvement. Even though numerous specific autoantibodies have been recognized, they have not been included, with the only exception of anti-Jo-1, into the 2017 Classification Criteria, thus perpetuating a clinical-serologic gap. The lack of homogeneous grouping based on the antibody profile deeply impacts the diagnostic approach, therapeutic choices and prognostic stratification of these patients. This review is intended to highlight the comprehensive scenario regarding myositis-related autoantibodies, from the molecular characterization and biological significance to target antigens, from the detection tools, with a special focus on immunofluorescence patterns on HEp-2 cells, to their relative prevalence and ethnic diversity, from the clinical presentation to prognosis. If, on the one hand, a notable body of literature is present, on the other data are fragmented, retrospectively based and collected from small case series, so that they do not sufficiently support the decision-making process (i.e. therapeutic approach) into the clinics.

Exosomes as a Nanodelivery System: a Key to the Future of Neuromedicine?

Since the beginning of the last decade, exosomes have been of increased interest in the science community. Exosomes represent a new kind of long distance transfer of biological molecules among cells. This review provides a comprehensive overview about the construction of exosomes, their targeting and their fusion mechanisms to the recipient cells. Complementarily, the current state of research regarding the cargo of exosomes is discussed. A particular focus was placed on the role of exosomes in the central nervous system. An increasing number of physiological processes in the brain could be associated with exosomes. In this context, it is becoming more apparent that exosomes are involved in several neurological and specifically neurodegenerative diseases. The treatment of these kinds of diseases is often difficult not least because of the blood-brain barrier. Exosomes are very stable, can pass the blood-brain barrier and, therefore, reveal bright perspectives towards diagnosis and therapeutic treatments. A prerequisite for clinical applications is a standardised approach. Features necessary for a standardised diagnosis using exosomes are discussed. In therapeutic terms, exosomes represent a promising drug delivery system able to pass the blood-brain barrier. One option to overcome the disadvantages potentially associated with the use of endogenous exosomes is the design of artificial exosomes. The artificial exosomes with a clearly defined therapeutic active cargo and surface marker ensuring the specific targeting to the recipient cells is proposed as a promising approach.

[Auto-immune diseases and cancers. Second part: auto-immune diseases complicating cancers and their treatment]

Autoimmune diseases may reveal or occur during the course of a neoplasia or its treatment. Autoimmune cytopenia, especially haemolytic anaemia, is common in lymphoproliferative disorders such as chronic lymphoid leukemia. The link between cancer and myositis is well established. Dermatomyositis is associated with an increased relative risk of cancer of 3.4 to 4.4. A combination of detection of antibodies against p155 and TEP-computed tomography may be the best approach to ascertain the presence of occult malignancy in patients with dermatomyositis. A cutaneous or a systemic vascularitis may reveal a cancer, most often a haematological malignancy such as hairy cell leukemia. Paraneoplastic polyarthritis have been described in particular with adenocardinoma of the lungs. Underlying neoplasia should be considered in male smokers patients with new onset polyarthritis and poor health status. The prevalence of autoimmune conditions in myelodysplastic syndromes is 10 to 30%. Vasculitis and relapsing polychondritis are the most commonly reported manifestations. Immune manifestations can also be related to treatment. The most common treatment complications are autoimmune haemolytic anaemia with fludarabine and thyroiditis related to interferon and cervical radiotherapy.

Camptocormia as a clinical manifestation of polymyositis/systemic sclerosis overlap myositis associated with anti-Ku

Camptocormia, an abnormal truncal flexion posture that occurs while walking or standing, is usually caused by various hypokinetic movement disorders, mainly Parkinson disease. We describe the case of a man with subacute onset of camptocormia. Quadriceps muscle biopsy showed significant rhabdomyolysis, few isolated inflammatory cells and mild expression of type I MHC in few fibers, a pattern usually found in immune-mediated necrotizing myopathies. Myositis was associated with Raynaud's phenomenon, mild sclerodactyly, and anti-Ku antibodies leading to the diagnosis of polymyositis/systemic sclerosis overlap myositis. The posture showed modest improvement in response to treatment.

Anti-ro52 antibodies and interstitial lung disease in connective tissue diseases excluding scleroderma

Introduction. The presence of anti-Ro52 antibodies has been reported in a wide variety of autoimmune diseases, particularly in myositis, scleroderma, and autoimmune liver diseases. Clinical significance of anti-Ro52 antibodies remains controversial, and studies are lacking for clarifying the association of anti-Ro52 with interstitial lung disease (ILD) in connective tissue diseases (CTD). Objectives. To determine if anti-Ro52 antibodies are associated with ILD in CTD other than scleroderma. Methods. Single-center, retrospective study based on immunoblotting panel analysis and patients clinical records. Results. In our connective tissue disease cohort, 162 patients had immunoblotting panels with anti-Ro52 reactivity analysis, 41 (25,3%) had inclusion criteria. Among the 41 selected sera, 85.4% (n = 35) had anti-Ro52 reactivity. The prevalence of ILD in the positive anti-Ro52 antibodies was 71.4% (n = 25), and 16.7% (n = 1) in the negative anti-Ro52 group (P = 0.018). Overall sensitivity (96.2%), specificity (83.3%), positive (71.4%) and negative (83.3%) predictive values of anti-Ro52 antibodies to determine ILD in CTD is detailed in this study. Conclusion. Ro52 autoantibodies are associated with ILD in CTD excluding scleroderma. We suggest that the presence of anti-Ro52 reactivity in CTD should increase the clinician curiosity for the search of ILD.

Clinical significance of anti-Ro52 (TRIM21) antibodies non-associated with anti-SSA 60kDa antibodies: results of a multicentric study

Ro52 antigen has recently been identified as TRIM21 protein, but the clinical significance of anti-Ro52/TRIM21 antibodies remains controversial. The aim of this multicentric study was to investigate the significance of anti-Ro52 antibodies without anti-SSA/Ro60 antibodies in various connective diseases. Sera were selected by each laboratory using its own method (ELISA, immunodot or Luminex technology), and then performed with ANA Screen BioPlex™ reagent (BIO-RAD). Among the 247 screened sera, 155/247 (63%) were confirmed as anti-Ro52 positive and anti-SSA/Ro60 negative. These sera were analyzed for the detection of other antibodies in relation with clinical settings. Isolated anti-Ro52 antibodies were detected in 89/155 (57%) sera. For the remaining sera (66/155), the main antibodies associations were Sm/SmRNP or Chromatin (n=38; 57%), Jo1 (n=17; 26%) and CenpB (n=9; 14%). Clinical data from the 155 patients showed high prevalence in autoimmune diseases (73%) including myositis or dermatomyositis (n=30), lupus (n=23); Sjögren and/or sicca syndrome (n=27); CREST or Systemic sclerosis (n=11) and autoimmune hepatitis (n=11). We found that pulmonary manifestations were often associated with the presence of anti-Ro52 antibodies (n=34, 22%), in addition with anti-tRNA synthetases, anti-SRP or anti-Ku antibodies (18/34) or isolated in half of cases (16/34). Separate detection of anti-Ro52 antibodies might be useful in related antisynthetase syndrome diagnosis. The presence of anti-Ro52 antibodies should probably precede development of autoimmune disease and must induce sequential follow-up of positive patients, particularly in interstitial lung disease progression.