Distinct arthropathies of the hands in patients with anti-aminoacyl tRNA synthetase antibodies: usefulness of autoantibody profiles in classifying patients

Review of Pulmonary Manifestations in Antisynthetase Syndrome

Antisynthetase syndrome (ASyS) is now a widely recognized entity within the spectrum of idiopathic inflammatory myopathies. Initially described in patients with a triad of myositis, arthritis, and interstitial lung disease (ILD), its presentation can be diverse. Additional common symptoms experienced by patients with ASyS include Raynaud's phenomenon, mechanic's hand, and fever. Although there is a significant overlap with polymyositis and dermatomyositis, the key distinction lies in the presence of antisynthetase antibodies (ASAs). Up to 10 ASAs have been identified to correlate with a presentation of ASyS, each having manifestations that may slightly differ from others. Despite the proposal of three classification criteria to aid diagnosis, the heterogeneous nature of patient presentations poses challenges. ILD confers a significant burden in patients with ASyS, sometimes manifesting in isolation. Notably, ILD is also often the initial presentation of ASyS, requiring pulmonologists to remain vigilant for an accurate diagnosis. This article will comprehensively review the various aspects of ASyS, including disease presentation, diagnosis, management, and clinical course, with a primary focus on its pulmonary manifestations.

Severe digital ischemia as an unrecognized manifestation in patients with antisynthetase autoantibodies: Case series and systematic literature review

Objective

Severe digital ischemia, including digital ulcers and gangrene, is considered rare in patients with antisynthetase antibodies. This study aimed to elucidate the clinical features of antisynthetase-positive patients complicated with digital ulcers and/or gangrene using a systematic literature review and case series in a single-center cohort.

Methods

A systematic literature review was conducted to identify reports describing antisynthetase-positive cases with digital ulcers and/or gangrene. Our cohort of consecutive patients with antisynthetase antibodies was stratified by the history of severe digital ischemia. Demographic and clinical features and outcomes in patients with severe digital ischemia identified in the systematic literature review and our cohort were compared with those in patients without severe digital ischemia in our cohort.

Results

The systematic literature review revealed 12 antisynthetase-positive patients with severe digital ischemia from one case series and eight case reports. Seven (7%) of 100 patients with antisynthetase antibodies in our cohort had a record of severe digital ischemia. Severe digital ischemia was often found at presentation and was associated with the classification of systemic sclerosis with or without myositis overlap. Clinical features associated with severe digital ischemia in antisynthetase-positive patients included Raynaud's phenomenon (p < 0.001), digital pitting scars (p = 0.001), and nailfold capillary abnormality (p = 0.02). Outcomes of severe digital ischemia were generally favorable with vasodilators.

Conclusion

Severe digital ischemia is an overlooked complication in antisynthetase-positive patients. Antisynthetase antibodies should be measured in patients presenting with digital ulcers or gangrene, especially in those with systemic sclerosis phenotype and features associated with antisynthetase antibodies in the absence of systemic sclerosis-specific autoantibodies.

Roles of aminoacyl-tRNA synthetases in immune regulation and immune diseases

Aminoacyl-tRNA synthetases (ARSs) play a vital role in protein synthesis by linking amino acids to their cognate transfer RNAs (tRNAs). This typical function has been well recognized over the past few decades. However, accumulating evidence reveals that ARSs are involved in a wide range of physiological and pathological processes apart from translation. Strikingly, certain ARSs are closely related to different types of immune responses. In this review, we address the infection and immune responses induced by pathogen ARSs, as well as the potential anti-infective compounds that target pathogen ARSs. Meanwhile, we describe the functional mechanisms of ARSs in the development of immune cells. In addition, we focus on the roles of ARSs in certain immune diseases, such as autoimmune diseases, infectious diseases, and tumor immunity. Although our knowledge of ARSs in the immunological context is still in its infancy, research in this field may provide new ideas for the treatment of immune-related diseases.

Clinical Spectrum Time Course in Anti Jo-1 Positive Antisynthetase Syndrome: Results From an International Retrospective Multicenter Study

Anti Jo-1 antibodies are the main markers of the antisynthetase syndrome (ASSD), an autoimmune disease clinically characterized by the occurrence of arthritis, myositis, and interstitial lung disease (ILD). These manifestations usually co-occur (for practical purpose complete forms) in the same patient, but cases with only 1 or 2 of these findings (for practical purpose incomplete forms) have been described. In incomplete forms, the ex novo occurrence of further manifestations is possible, although with frequencies and timing not still defined. The aim of this international, multicenter, retrospective study was to characterize the clinical time course of anti Jo-1 positive ASSD in a large cohort of patients. Included patients should be anti Jo-1 positive and with at least 1 feature between arthritis, myositis, and ILD. We evaluated the differences between complete and incomplete forms, timing of clinical picture appearance and analyzed factors predicting the appearance of further manifestations in incomplete ASSD. Finally, we collected 225 patients (58 males and 167 females) with a median follow-up of 80 months. At the onset, complete ASSD were 44 and incomplete 181. Patients with incomplete ASSD had frequently only 1 of the classic triad findings (110 cases), in particular, isolated arthritis in 54 cases, isolated myositis in 28 cases, and isolated ILD in 28 cases. At the end of follow-up, complete ASSD were 113, incomplete 112. Only 5 patients had an isolated arthritis, only 5 an isolated myositis, and 15 an isolated ILD. During the follow-up, 108 patients with incomplete forms developed further manifestations. Single main feature onset was the main risk factor for the ex novo appearance of further manifestation. ILD was the prevalent ex novo manifestation (74 cases). In conclusion, ASSD is a condition that should be carefully considered in all patients presenting with arthritis, myositis, and ILD, even when isolated. The ex novo appearance of further manifestations in patients with incomplete forms is common, thus indicating the need for an adequate clinical and instrumental follow-up. Furthermore, the study clearly suggested that in ASSD multidisciplinary approach involving Rheumatology, Neurology, Pneumology, and Internal Medicine specialists is mandatory.