Jo-1 syndrome with associated poorly differentiated adenocarcinoma

Aminoacyl-tRNA Synthetases: On Anti-Synthetase Syndrome and Beyond

Anti-synthetase syndrome (ASSD) is an autoimmune disease characterized by the presence of autoantibodies targeting one of several aminoacyl t-RNA synthetases (aaRSs) along with clinical features including interstitial lung disease, myositis, Raynaud’s phenomenon, arthritis, mechanic’s hands, and fever. The family of aaRSs consists of highly conserved cytoplasmic and mitochondrial enzymes, one for each amino acid, which are essential for the RNA translation machinery and protein synthesis. Along with their main functions, aaRSs are involved in the development of immune responses, regulation of transcription, and gene-specific silencing of translation. During the last decade, these proteins have been associated with cancer, neurological disorders, infectious responses, and autoimmune diseases including ASSD. To date, several aaRSs have been described to be possible autoantigens in different diseases. The most commonly described are histidyl (HisRS), threonyl (ThrRS), alanyl (AlaRS), glycyl (GlyRS), isoleucyl (IleRS), asparaginyl (AsnRS), phenylalanyl (PheRS), tyrosyl (TyrRS), lysyl (LysRS), glutaminyl (GlnRS), tryptophanyl (TrpRS), and seryl (SerRS) tRNA synthetases. Autoantibodies against the first eight autoantigens listed above have been associated with ASSD while the rest have been associated with other diseases. This review will address what is known about the function of the aaRSs with a focus on their autoantigenic properties. We will also describe the anti-aaRSs autoantibodies and their association to specific clinical manifestations, and discuss their potential contribution to the pathogenesis of ASSD.

Antisynthetase syndrome: A distinct disease spectrum

The discovery of novel autoantibodies related to idiopathic inflammatory myopathies (collectively referred to as myositis) has not only advanced our understanding of the clinical, serological, and pathological correlation in the disease spectrum but also played a role in guiding management and prognosis. One group of the myositis-specific autoantibodies is anti-aminoacyl-tRNA synthetase (anti-ARS or anti-synthetase) which defines a syndrome with predominant interstitial lung disease, arthritis, and myositis. Autoantibodies to eight aminoacyl-tRNA synthetases have been identified with anti-Jo1 the most common in all of idiopathic inflammatory myopathies. Disease presentation and prognosis vary depending on which anti-aminoacyl-tRNA synthetase antibody is present. In this review, we will discuss the clinical characteristics, overlap features with other autoimmune diseases, prognostic factors, and management of the antisynthetase syndrome.

Squamous cell carcinoma of the lung associated with anti-Jo1 antisynthetase syndrome: a case report and review of the literature

Antisynthetase syndrome is a heterogeneous idiopathic inflammatory myopathy. Anti-Jo1 is the most common antibody found in this condition. Dermatomyositis is known to be associated with malignancy, but the association between antisynthetase syndrome and malignancy is not clearly established. We report a case of an association of squamous cell carcinoma of the lung and anti-Jo1 antisynthetase syndrome. A 67-year-old man presented with polyarthritis, muscle weakness of the pelvic girdle, "mechanic's hands," and weight loss. A diagnosis of antisynthetase syndrome was considered based on the clinical features and the presence of anti-Jo1 antibodies. Positron emission tomography was performed because of weight loss and revealed a pulmonary hypermetabolic lesion. Histological findings revealed squamous cell carcinoma. The patient underwent lobectomy and is currently free of symptoms with regular monitoring. This unusual presentation of squamous cell carcinoma of the lung illustrates the need of a systematic approach to the diagnosis of antisynthetase syndrome. Positron emission tomography can be a useful imaging modality in the diagnosis of paraneoplastic syndromes associated with antisynthetase syndrome especially in the presence of warning signs/symptoms.

An Unusual Suspect Causing Hypoxemic Respiratory Failure

Introduction: Antisynthetase syndrome (ASS) is characterized by the presence of anti-Jo-1 antibodies in conjunction with clinical findings of fever, polymyositis-dermatomyositis, and interstitial lung disease (ILD). Inflammatory myopathies carry a high risk of malignancy, but this association is less well outlined in ASS. We present the case of a patient with ASS who developed non-Hodgkin's lymphoma with acute hypoxemic respiratory failure. Case Presentation: A 44-year-old female with ASS presented with acute hypoxemic respiratory failure. She was empirically treated with broad-spectrum antibiotics for a health care-associated pneumonia; however, she failed to improve. Chest computed tomography revealed extensive bilateral ground glass opacities as well as extensive mediastinal and axillary lymphadenopathy. Infectious workup was negative. A surgical lung biopsy revealed peripheral T-cell lymphoma (PTCL). The patient was started on chemotherapy with complete resolution of hypoxemic respiratory failure. Conclusions: Malignancy is very rare in the setting of ASS; and our case illustrates the unique presentation of PTCL in ASS. In addition, lung involvement in PTCL is variable (incidence ranging from 8% to 20%); and in this case, bilateral multifocal consolidation was biopsied and proven to be PTCL involving the lungs. This case highlights the rare noninfectious conditions that can present as acute hypoxemic respiratory failure in the setting of ASS.

Idiopathic Inflammatory Myopathies and Malignancy: a Comprehensive Review

The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of autoimmune diseases (collectively known as myositis) affecting the skeletal muscles as well as other organ systems such as skin, lungs, and joints. The primary forms of myositis include polymyositis (PM), dermatomyositis (PM), and immune-mediated necrotizing myopathy (IMNM). Patients with these diseases experience progressive proximal muscle weakness, have characteristic muscle biopsy findings, and produce autoantibodies that are associated with unique clinical features. One distinguishing feature of these patients is that they are also known to have an increased risk of cancer. Since the first description of the association in 1916, it has been extensively reported in the medical literature. However, there have been significant variations between the different studies with regard to the degree of cancer risk in patients with IIM. These discrepancies can, in part, be attributed to differences in the definition of malignancy-associated myositis used in different studies. In recent years, significant advances have been made in defining specific features of IIM that are associated with the development of malignancy. One of these has been myositis-specific antibodies (MSAs), which are linked to distinct clinical phenotypes and categorize patients into groups with more homogeneous features. Indeed, patients with certain MSAs seem to be at particularly increased risk of malignancy. This review attempts a systematic evaluation of research regarding the association between malignancy and myositis.

[Prevalence of cancer in the Afro-Caribbean population presenting dermatomyositis and anti-synthetase syndrome: a preliminary study conducted at Pointe-à-Pitre University Hospital, 2000-2012]

BACKGROUND

An association with cancer is described in 17-32% of cases of dermatomyositis (DM) and in 5-16% of cases of anti-synthetase syndrome (ASS). The literature contains very few studies involving Afro-Caribbean patients with DM or ASS. The aim of our retrospective study was to determine the prevalence of cancer in a series of patients with DM or ASS at the University Hospital of Pointe-à-Pitre between 1st January 2000 and 31st December 2012. The secondary objective was to review the clinical and laboratory features as well as the course of DM/ASS in these patients.

PATIENTS AND METHODS

The inclusion criteria were as follows: Afro-Caribbean origin; age >15 years; patient living in Guadeloupe; screening for malignancy.

RESULTS

Twenty-two patients were included (15 DM, 7 ASS). Only one case of cancer was diagnosed in the entire study population at a mean follow-up of 6 ± 4 years (prevalence: 6.7%, CI95% [1.7-31.9]). Of the 15 patients presenting DM (sex ratio F/M: 4, mean age: 45 ± 14 years), 6 (40%) had associated connective tissue disease.

CONCLUSION

Our study suggests a weak association between DM and cancer in Afro-Caribbean patients. These results may be explained by the features of the disease seen in these patients (female gender, young age at onset, associated connective tissue disease) and the low prevalence in the Caribbean region of cancers typically associated with DM.

Cancer-associated myositis: a 35-year retrospective study of a monocentric cohort

This study is aimed at retrospectively studying cancer-associated inflammatory myopathies (CAM) in a cohort of patients with inflammatory myopathies. CAM were diagnosed if the tumor was diagnosed 2 years before or after disease onset. One hundred and sixty-two patients were included, 27 (17 %) had CAM. A significant association was observed between CAM and dermatomyositis (DM), older age and dysphagia at disease onset. CAM have lower creatine kinase (CK) levels at onset and a low prevalence of autoantibodies. In conclusion, the association of male sex, older age, DM, dysphagia at onset, lower CK, and autoantibodies negativity carries a high suspicion of CAM.

Comparison of long-term outcome between anti-Jo1- and anti-PL7/PL12 positive patients with antisynthetase syndrome

The aims of the present study were to: compare the characteristics between antisynthetase syndrome (ASS) patients with anti-Jo1 antibody and those with anti-PL7/PL12 antibody. The medical records of 95 consecutive patients with ASS were reviewed. Seventy-five of these patients had anti-Jo1 antibody; the other patients had anti-PL7 (n=15) or anti-PL12 (n=5) antibody. At ASS diagnosis, the prevalence of myalgia (p=0.007) and muscle weakness (p=0.02) was significantly lower in the group of anti-PL7/PL12-positive patients than in those with anti-Jo1 antibody; median value of CK (p=0.00003) was also lower in anti-PL7/PL12 patients. Anti-Jo1 positive patients developed more rarely myositis resolution (21.3% vs. 46.2%); in addition, the overall recurrence rate of myositis was higher in anti-Jo1 positive patients than in patients with anti-PL7/PL12 antibody (65.9% vs. 19.4%). Anti-Jo1-positive patients, compared with those with anti-PL7/PL12 antibody, more often experienced: joint involvement (63.3%vs. 40%) and cancer (13.3% vs. 5%). By contrast, anti-PL7/PL12 positive patients, compared with those with anti-Jo1 antibody, more commonly exhibited: ILD (90% vs. 68%); in anti-PL7/PL12 positive patients, ILD was more often symptomatic at diagnosis, and led more rarely to resolution of lung manifestations (5.6% vs. 29.4%). Finally, the group of anti-PL7/PL12 positive patients more commonly experienced gastrointestinal manifestations related to ASS (p=0.02). Taken together, although anti-Jo1 positive patients with ASS share some features with those with anti-PL7/PL12 antibody, they exhibit many differences regarding clinical phenotype and long-term outcome. Our study underscores that the presence of anti-Jo1 antibody results in more severe myositis, joint impairment and increased risk of cancer. On the other hand, the presence of anti-PL7/PL12 antibody is markedly associated with: early and severe ILD, and gastrointestinal complications. Thus, our study interestingly indicates that the finding for anti-Jo1 and anti-PL7/PL12 antibodies impacts both the long-term outcome and prognosis of patients with ASS.

Paraneoplastic myalgias and myositis

There are several key observations on paraneoplastic myopathies: The risk of cancer associated with DM is very high, whereas risk of cancer associated with PM is mildly increased Most cancers develop within one year of the onset of myositis, although the risk remains high up to 5 years after diagnosis. The most common cancers associated with DM are adenocarcinoma, including lung, ovary, cervical, stomach, pancreas, colorectal and lymphoma, whereas PM is associated with a high risk of lymphoma. The clinical course of myopathy is closely linked with the course of cancer. Certain clinical features are associated with CAM including severe treatment resistant skin manifestations, severe muscle weakness, respiratory muscle weakness, and dysphagia, while some clinical features are protective such as arthritis, Raynaud, and ILD. Screening should be based on age, gender, ethnicity, and the geographic area of the patient; however, certain high-risk patients may require more extensive screening including tumor markers and thoracoabdominal–pelvic CT scans. Certain autoantibodies including anti-p155 and the absence of more common autoantibodies are associated with a higher risk of CAM, while the presence of antisynthetase autoantibodies lowers the risk for CAM. Although the pathogenesis of CAM is unclear, a plausible hypothesis is that immune responses generated against antigens commonly targeted in myositis are related to antitumor responses in affected individuals.

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

The inflammatory myopathies are a group of quite proteiform, systemic auto-immune diseases which include polymyositis, dermatomyositis and inclusion body myopathies. To facilitate the diagnosis, classification criteria (Bohan and Peter, 1975) have been proposed, based essentially on clinical criteria. In addition, over the past fifteen years, auto-antibodies characterizing certain forms of inflammatory myopathy have been identified. One distinguishes schematically: auto-antibodies specific for myositis and auto-antibodies sometimes associated with myositis. Concerning the myositis specific auto-antibodies (MSA), schematically there are a dozen specificities which are classed according to the cellular distribution of the auto-antigen. The most characteristic are certainly the auto-antibodies directed against cytoplasmic antigens: the anti-tRNA synthetases (anti-Jo-1 (PL-1), anti-PL-7, PL-12, EJ, OJ, JS, KS, ZO, YRS), anti-SRP (signal recognition particle), anti-Mas and anti-KJ, anti-Fer (eEF1), anti-Wa and anti-CADM p140. Other auto-antibodies are directed against nuclear auto-antigens: the anti-Mi-2, anti-PMS (PMS1, PMS2) and related antibodies (MLH1, DNA PKcs…), anti-56 kDa, anti-MJ (NXP-2), anti-SAE and anti-p155/p140 (TIF-1γ). Concerning the auto-antibodies sometimes associated with myositis (myositis associated auto-antibodies or MAA), they can also be observed in other auto-immune diseases. These auto-antibodies are directed against nuclear or nucleolar auto-antigens: the anti-PM-Scl, anti-Ku, anti-RNP (U1 RNP and U2 RNP, U4/U6 RNP and U5 RNP), anti-Ro 52 kDa and more rarely, anti-Ro 60 kDa and anti-La. The auto-antibodies related to myositis are biological tools which are of interest in two main ways. They have allowed us to sort out the nosology of these inflammatory myopathies, in particular by defining anti-tRNA synthetase syndrome. It now remains to determine how they might be employed to complement the classical clinico-biological diagnostic criteria. In this perspective, it will be indispensable first of all to diffuse and standardize the methods of detection. The latter are at the moment very heterogeneous as they use techniques and above all antigenic preparations which are extremely diverse. These antibodies are also very interesting "physiopathological" tools to try to better understand myositis. The example of anti-tRNA synthetases is a particularly original model of auto-immunization, which allows one to establish a link between an initial, probably poorly specific muscular lesion and the appearance of auto-antibodies which maintain and aggravate the muscular disease.

Malignancy in the setting of the anti-synthetase syndrome

Malignancy and interstitial lung disease (ILD) are 2 conditions associated with dermatomyositis (DM) that are responsible for a significant portion of the morbidity and mortality related to this disease; however, they rarely occur in the same patient. The antisynthetase syndrome consists of several characteristics, including ILD, arthritis, Raynaud phenomenon, "mechanic's hands," and positive antibodies to tRNA synthetases, which have each been negatively associated with cancer. When patients with DM present with such characteristics, clinicians may be falsely reassured that a thorough malignancy screen is unnecessary. We describe a patient who presented with the antisynthetase syndrome and was subsequently found to have colon cancer. Removal of the cancer led to resolution of the myositis and lung disease, but the patient's rash and arthritis persisted and ultimately required immunosuppressive therapy. We provide a review of the literature describing the concurrence of both this syndrome and ILD alone, with malignancy. We conclude that a thorough and expedited age-appropriate malignancy work up is indicated in all patients with a new diagnosis of DM, despite the presence of disease characteristics that are usually not associated with cancer.

Paraneoplastic polymyositis associated with crescentic glomerulonephritis

A female concurrently developed polymyositis (PM), lung cancer, and nephrotic range proteinuria. Renal biopsy revealed crescentic glomerulonephritis. Pathology of lung cancer was proved to be adenocarcinoma. After surgical treatment of lung cancer, the symptoms of PM-associated crescentic glomerulonephritis disappeared. PM is associated with a higher risk of malignancy, though renal involvement in patients with PM is thought to be uncommon. In patients with PM, there have been few reports concerning the coexistence of glomerular disease, including crescent glomerulonephritis. Herein we report a case of crescentic glomerulonephritis-associated PM that was successfully treated after the surgical removal of lung cancer. We consider that such association of PM and crescent glomerulonephritis is rare in adults. Careful evaluation of underlying malignancy is important. The definite treatment is adequate management of underlying malignancy.

Hodgkin’s lymphoma in a patient with Jo-1 syndrome

Jo-1 syndrome is an autoimmune disease with autoantibodies against the histidyl tRNA synthetase. Characteristic clinical findings include inflammatory myopathy and interstitial lung disease. We present the first case of a patient with Jo-1 syndrome (positive Jo-1 autoantibodies, myositis, interstitial alveolitis) who developed Hodgkin's lymphoma of nodular-sclerosing type. Thus, patients with Jo-1 syndrome and immunosuppressive therapy similar to other patients with autoimmune disease are at risk to develop lymphomas and should therefore be monitored carefully.

Contribution of autoantibodies to the diagnosis and nosology of inflammatory muscle disease

The myositides are systemic autoimmune conditions of which the most important are polymyositis, dermatomyositis, and inclusion body myositis. In addition to the classic clinical diagnostic criteria, myositis-specific autoantibodies were identified about 15 years ago. Among the dozen or so myositis-specific autoantibodies reported to date, the most characteristic are directed against cytoplasmic antigens, such as tRNA synthetase (Jo-1 or PL-1, PL-7, PL-12, EJ, OJ, JS, and KS), signal-recognition particle (SRP), Mas, KJ, Fer (eEF1), and Wa. Antibodies to nuclear antigens include anti-Mi-2, anti-PMS (PMS1, and PMS2), and related antibodies (MLH1, DNA protein kinase catalytic subunit (DNA PKCS)...), and anti-56 kDa. Myositis-associated antibodies are not specific but may be found in patients with myositis. They are directed to nuclear or nucleolar antigens such as PM-Scl, Ku, RNP (U1-RNP and U2-RNP, U4/U6-RNP, and U5-RNP), Ro 52 kDa and, more rarely, Ro 60 kDa and La. Myositis-specific antibodies have proved useful on two fronts. They have improved the diagnosis of myositis by leading to the identification of characteristic clinical patterns, such as anti-synthetase syndrome. The place of autoantibodies alongside classic clinical and laboratory criteria remains to be determined, however. First, standardized assays will have to be developed to replace current detection methods, which use widely variable techniques and antigen preparations. Myositis-specific antibodies have also shed light on the pathogenesis of myositis. For instance, the development of antibodies to tRNA synthetases constitutes an original autoimmunity model that shows how muscle damage, probably of a nonspecific nature, can lead to the production of autoantibodies that perpetuate and aggravate the muscle lesions.

Myositis specific autoantibodies

Recent studies have continued to examine the clinical associations of the group of autoantibodies that occurs predominantly in patients who have myositis (antibodies to aminoacyl-tRNA synthetases, to signal recognition particle [SRP], and to the nuclear helicase Mi-2). The anti-synthetase syndrome has been further studied, and the value of tacrolimus in treatment of the associated interstitial lung disease has been noted. The low frequency of myositis specific autoantibodies in non-myositis neuromuscular disorders has been more clearly demonstrated. The clinical associations of anti-Mi-2 and anti-SRP were further studied, and patients with antibodies without myositis were reported. Evidence suggested that ultraviolet light exposure may influence the expression of dermatomyositis and anti-Mi-2. A new classification for myositis using overlap clinical features and autoantibodies was proposed. A new autoantibody, anti-caDM-140, was described, associated with clinically amyopathic dermatomyositis and interstitial lung disease. The possibility was raised that increased antigen expression in regenerating muscle may help to perpetuate the disease. These antibodies continue to be the subject of active investigation.

Myositis: an update on pathogenesis

PURPOSE OF REVIEW

The etiology and much about the pathogenesis of the inflammatory myopathies remain a mystery. In this review, we investigate recent research efforts to understand the pathogenesis of the diverse entities of polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM), diseases that result from interactions between environmental risk factors and genetic susceptibility.

RECENT FINDINGS

Over the past year, there has been considerable progress toward better understanding of IBM, with relatively few developments toward understanding PM and DM. Although these diseases may share some common clinical phenotypic and serologic components, they differ on a molecular and cellular level.

SUMMARY

The need for definitive, safer therapies in these diseases makes vital the search for defining detailed pathogenesis of inflammation and muscle fiber damage at the molecular level.