Dermatomyositis without Apparent Myositis, Complicated by Fibrosing Alveolitis

Fatal Rapidly Progressive Interstitial Pneumonitis Associated With Amyopathic Dermatomyositis and CD8 T Lymphocytes

A patient with amyopathic dermatomyositis associated with fatal rapidly progressive interstitial pneumonitis resistant to therapy is described. Pathologic examination of a transbronchial lung biopsy specimen showed diffuse alveolar damage and nonspecific interstitial pneumonia-organizing pneumonia-like findings. Bronchoalveolar lavage fluid contained many CD8+ lymphocytes, considered to be cytotoxic T cells. Analysis of bronchoalveolar lavage fluid in this case may provide prognostically and pathogenetically important information.

Anti-aminoacyl-tRNA synthetase antibodies in clinical course prediction of interstitial lung disease complicated with idiopathic inflammatory myopathies

In the treatment of polymyositis and dermatomyositis (PM/DM), the complication of interstitial lung disease (ILD) is an important prognostic factor. It has been reported that autoantibodies against aminoacyl-tRNA synthetases (ARS) are strongly associated with ILD. The aim of this study is to examine the correlation between anti-ARS and the clinical course of ILD. We investigated 41 cases of PM/DM with ILD. The response of ILD to corticosteroids (CS) was determined according to the change in respiratory symptoms, image findings, and pulmonary function between, before and 2 months after the treatment. Anti-ARS (anti-Jo-1, PL-7, PL-12, EJ, OJ and KS) antibodies were screened with the RNA immunoprecipitation assay. In the stratification into ILD-preceding, simultaneous and myopathy-preceding types, anti-ARS antibodies were significantly frequent in the ILD-preceding type (p < 0.05). In the stratification into anti-ARS-positive and negative groups, the response of ILD to CS was significantly better in the positive group (p < 0.05). However, recurrence of ILD was significantly more frequent in the positive group (p < 0.01), and 2 year prognoses of pulmonary function (%VC and %DLCO) were not different between the two groups. In conclusion, screening of anti-ARS may be useful to predict late-onset myopathy in ILD-preceding patients and to predict the clinical course of ILD in PM/DM patients.

Interstitial lung disease associated with amyopathic dermatomyositis: Review of 18 cases

Interstitial lung disease (ILD) associated with amyopathic dermatomyositis (ADM) is a rare and sometimes fatal condition whose clinical features are not well understood. The goal of this study was to clarify the characteristics of ILD based on its development. Eighteen patients diagnosed with ILD associated with ADM were assigned to 1 of 2 groups: (1) a rapidly progressing group, which included patients who developed abnormal lung findings within 1 month of being diagnosed with ADM (n=9); or (2) a slowly progressing group, which including patients who developed lung findings greater than 1 month after diagnosis of ADM (n=9). Serum creatine phosphokinase and C-reactive protein levels were higher in the rapidly progressing group than in the slowly progressing group. Further, arterial pH was higher and PaO(2)/F(I)O(2) was lower in the rapidly progressing group than in the slowly progressing group. On thoracic high-resolution CT, traction bronchiectasis was present in 4 of the 9 rapidly progressing patients but not in any patients of the slowly progressing group. All 9 slowly progressing patients survived with proper treatment, but only 4 of the 9 rapidly progressing patients survived. In ADM, appropriate investigations are likely required for the early diagnosis of ILD. Our data suggest that ILD associated with ADM can be classified into 2 clinical subtypes based on the time course of pulmonary involvement. Patients with rapid progression in respiratory symptoms should undergo intensive treatment as soon as possible to promote favorable outcomes.

A systematic review of adult-onset clinically amyopathic dermatomyositis (dermatomyositis siné myositis): a missing link within the spectrum of the idiopathic inflammatory myopathies

OBJECTIVE

Classical dermatomyositis (CDM) patients display the hallmark cutaneous manifestations of dermatomyositis (DM), proximal muscle weakness, and laboratory evidence of myositis. The epidemiology and management of both adult-onset and juvenile-onset CDM has been well characterized. However, the clinical significance of the hallmark inflammatory cutaneous manifestations of DM occurring in individuals who have no clinically significant muscle weakness and normal muscle enzymes for prolonged periods of time (ie, 6 months or longer) has not been clear. The term amyopathic DM (ADM) (synonymous with DM siné myositis) has been proposed to draw attention to such individuals. A related form of DM, "hypomyopathic DM" [HDM], is the presence of DM skin disease for 6 months or longer in individuals who have no muscle weakness but who are found to have some evidence of muscle inflammation upon testing (muscle enzyme levels, electromyogram, muscle biopsy, muscle magnetic resonance imaging [MRI]). Clinically amyopathic DM (CADM) is a designation that has been proposed for patients having either ADM or HDM. The clinically amyopathic component of this designation was coined to emphasize the fact that the only clinical problem being experienced by these patients at the time of diagnosis is their DM skin disease. Our personal experience suggests that the CADM subphenotype might be more prevalent in adults than has been thought previously. To test this hypothesis and address questions relating to the optimal management and prognosis of such patients, we have systematically reviewed the published literature in this area.

METHODS

We carried out a systematic review of the published literature on adult-onset CADM as defined in Table 1 through May 1, 2004.

RESULTS

We identified 291 adult-onset CADM cases (18 years or older) reported from over 19 countries. The average duration of DM skin disease was 3.74 years (range, 6 months [by definition] to > 20 years), and 73% were female. Among 37 patients with HDM who were identified, the average duration of disease was 5.4 years, and none had developed clinically significant weakness at the time of the reports. Thirty-seven of the reported CADM patients developed muscle weakness greater than 6 months after onset of their skin disease (15 months to 6 years). For the sake of this discussion, such patients have been analyzed under the designation of "CADM --> CDM." Somewhat surprisingly, 36/291 (13%) of the identified published CADM patients developed interstitial lung disease. Incidental to our review, we also identified 10 published cases of individuals having DM skin disease and interstitial lung disease without muscle weakness, 7 of whom died from interstitial lung disease less than 6 months after onset of their DM skin disease (the term pre-myopathic DM coined by others has been used here to refer to such patients). In addition, an associated internal malignancy was found in 41/291 (14%) of the identified CADM cases. A positive antinuclear antibody was reported in 63% and myositis-specific autoantibodies (eg, Jo-1, Mi-2) in only 3.5% of the reported CADM patients in which such data were available.

CONCLUSIONS

The results of this analysis suggests that the CADM subphenotype is more common than has been thought previously and that such patients may comprise a relatively high proportion of DM patients followed by dermatologists. Some CADM patients also have been observed to develop overt proximal muscle weakness years after onset of their DM skin disease. In addition, CADM patients appear to be at risk of developing the same potentially fatal disease associations/complications for which CDM patients are at risk (eg, interstitial lung disease and internal malignancy). Population-based studies of the epidemiology and optimal management of CADM patients, including efforts to identify risk factors associated with potentially fatal outcomes such as late-onset muscle weakness, interstitial lung disease, and malignancy, are needed. As an incidental finding to this literature review, we also identified a small number of reported cases of often-fatal interstitial lung disease occurring shortly after the onset of DM skin disease (< 6 months) in the complete absence of muscle weakness. This subphenotype, referred to as "pre-myopathic DM," is one with which dermatologists should be aware as early diagnosis and aggressive management can be lifesaving.

Three cases of 'mechanic's hands' associated with interstitial pneumonia: possible involvement with foot lesions

We describe three cases of the rare combination of lateral erythema and hyperkeratosis of the fingers that typify a condition known as 'Mechanic's Hands'. The first and the third cases were unusual in that the condition was associated with cutaneous involvement of the feet and interstitial pneumonia but not with myositis, or with only mild muscular involvement, while the second case was typical, being accompanied by myositis and detectable antibodies against histidyl transferase. We propose that Mechanic's Hands can occur in association with foot lesions and interstitial pneumonia, even if it is not accompanied by myositis.

Fatal interstitial pulmonary fibrosis in anti-Jo-1-negative amyopathic dermatomyositis

Amyopathic dermatomyositis (DM) describes a subpopulation with the cutaneous eruption of DM, but without muscle involvement. Interstitial pulmonary fibrosis is a recognized complication of DM, often correlated with antisynthetase enzymes, such as anti-Jo-1. We describe a case of fatal IPF in a patient with anti-Jo-1 antibody-negative amyopathic DM.

Prevention of progression of interstitial lung lesions by early combination therapy with corticosteroids and cyclosporine/cyclophosphamide in two patients with amyopathic dermatomyositis

Two patients with amyopathic dermatomyositis complicated by interstitial lung lesions were effectively treated with a combination of corticosteroids and cyclosporine and/or cyclophosphamide. A 48-year-old female patient was treated with pulse methylprednisolone and cyclosporine 2 months after onset of dermal symptoms. A 45-year-old male patient was treated with oral prednisolone and pulse cyclophosphamide 2 1/2 months after onset of dermal symptoms. Early evaluation of interstitial lung lesions and early extensive therapy may improve prognosis of interstitial lung lesions in patients with amyopathic dermatomyositis.

Dermatomyositis: an overview of recent progress with emphasis on dermatologic aspects

Important points regarding DM and C-ADM are as follows: C-ADM is a working functional designation for patients having the skin-only and skin-predominant subsets of DM, amyopathic DM, and hypomyopathic DM. C-ADM seems to have approximately 10% the incidence of classic DM in whites and possibly a higher incidence in Asians. Some patients who present with C-ADM, with or without subclinical laboratory abnormalities, can slowly progress to develop symptomatic muscle weakness over a period of years, whereas others go for 10 to 20 years and longer without the appearance of muscle weakness. C-ADM patients are at risk for potentially life-threatening complications of classic DM, such as interstitial lung disease, which may occur in up to 10% of C-ADM patients. This risk seems to be even greater in some ethnic subgroups (e.g., Japanese). C-ADM patients may also be at increased risk for internal malignancy and until further studies are carried out to confirm the statistical significance of this association, all such patients should have a thorough evaluation for internal malignancy, identical to the approach currently used in classic DM patients. Dermatologists are in the best position initially to diagnose C-ADM patients and can contribute greatly to their overall management and quality of life. Ongoing vigilance is required, however, for complications that can arise in C-ADM patients including potentially fatal interstitial lung disease, internal malignancy, delayed onset of muscle weakness from myositis, and complications of systemic drug therapy. Topical therapy with broad-spectrum sunscreens, anti-inflammatories, and antipruritics should be maximized during the initial management of the cutaneous manifestations of either classic DM or C-ADM. Single-agent or combined aminoquinoline antimalarial therapy represents the safest initial form of systemic therapy for DM-specific skin disease occurring in any clinical setting; however, this approach tends to be less effective in general than for cutaneous LE. There is a theoretical rationale for and limited preliminary successful anecdotal experience with the use of anti-TNF-alpha therapy in refractory cases of classic DM and C-ADM. Cautious systematic clinical trials in this area should be considered.

Dermatomyositis associated with rapidly progressive fatal interstitial pneumonitis and pneumomediastinum

We describe two cases of dermatomyositis (DM), which subsequently developed into rapidly progressive fatal interstitial pneumonitis and pneumomediastinum during steroid therapy. Both cases showed the classical cutaneous manifestations of DM, but the muscular symptoms were absent or mild. Both rapidly progressive interstitial pneumonitis and pneumomediastinum can occur in DM showing less inflammatory changes in the muscles. Patients with this form should be treated with extreme caution.

Dermatomyositis

Dermatomyositis is a rare inflammatory myopathy with characteristic skin manifestations and muscular weakness. The disease can be categorized as adult idiopathic, juvenile, or amyopathic dermatomyositis as well as that associated with a connective tissue disease or a malignancy. Immunologic factors are most likely involved in the pathogenesis of the disease; however, genetic and environmental issues may also play important roles. Treatment with immunosuppressive agents has proved successful in the majority of patients, although significant morbidity still occurs.

Amyopathic dermatomyositis: a review

Jim Gilliam's research interests throughout his career were forced upon better defining the relationships that exist between the cutaneous and systemic manifestations of the rheumatic diseases. Although the majority of his time was spent studying such relationships in lupus erythematosus patients, he was also intensely interested in dermatomyositis (DM) in this regard as well. He was particularly intrigued with the dissociation of the cutaneous and muscular manifestations of this disorder that occasionally occurs. The term "dermatomyositis siné myositis" has been used in the past to describe patients who present with only the cutaneous manifestations of DM; however, very little published data is available from systematic examinations of such patients. For several reasons, we have preferred the term "amyopathic dermatomyositis" to describe that rare patient who for long periods of time suffers from the classical skin lesions of DM as the only clinically significant manifestation of their disease. In this presentation, we review our own personal experience with a group of six such patients and compare and contrast it to that of other workers who have dealt with this subject over the past two decades.

Interstitial lung disease in polymyositis and dermatomyositis. Clinical features and prognosis as correlated with histologic findings

Open lung biopsies from 14 patients and autopsy tissue from one patient with polymyositis/dermatomyositis were reviewed in an attempt to correlate histologic features with clinical, radiographic, and prognostic variables. Three major groups based on histologic patterns were identified: bronchiolitis obliterans organizing pneumonia (BOOP), usual interstitial pneumonia (UIP), and diffuse alveolar damage (DAD). Patients with BOOP had a more favorable prognosis than did patients with UIP. Patients with DAD had a uniformly poor prognosis. One patient had a cellular interstitial pneumonia and did well. Histologic subclassification of the interstitial lung disease proved to be a better predictor of survival than did the radiographic appearance or the clinical presentation. These findings suggest that there is a broader range of histologic findings in polymyositis-dermatomyositis than is suggested in the literature and subclassification may be useful for prognosis.

Clinical manifestations in patients with antibody to PL-12 antigen (alanyl-tRNA synthetase)

PURPOSE

Anti-PL-12 antibody is directed at the enzyme alanyl-tRNA synthetase (ARS). Studies have clearly associated anti-Jo-1, also directed at an aminoacyl-tRNA synthetase (histidyl-tRNA synthetase), with a subgroup of myositis marked by a high frequency of interstitial lung disease (ILD) and arthritis. A similar syndrome has been reported in patients with antibodies to PL-12, but few patients have been studied. We describe the clinical manifestations in a new series of patients with antibody to PL-12.

PATIENTS AND METHODS

Sera from patients with polymyositis and sera found to contain anticytoplasmic antibodies were screened for antibody to PL-12 by testing for inhibition of ARS enzymatic activity by serum, and by immunoprecipitation.

RESULTS

Nine sera inhibited ARS. These nine plus two additional sera with anticytoplasmic antibodies immunoprecipitated an identical pattern of tRNAs and a polypeptide of 110 kd. Of the 10 patients that could be evaluated, eight had some evidence of myositis, including six that satisfied the criteria for myositis. Three of these six, all with dermatomyositis, had severe muscle involvement. Eight of the 10 patients had radiographic evidence of pulmonary fibrosis, and seven of the eight had clinical pulmonary impairment, including four with clinically severe ILD. Joint manifestations were found in five patients, and arthritis was the only clinical problem in one patient.

CONCLUSION

We conclude that anti-PL-12, like anti-Jo-1 and anti-PL-7, was frequently associated with the "Jo-1 syndrome" of myositis with ILD. ILD was a major clinical problem in this group of patients.

Interstitial lung disease as the presentation of anti-Jo-1 positive polymyositis

A patient presenting with interstitial lung disease was predicted to have underlying polymyositis when found to be anti-Jo-1 antibody positive. When myopathy developed later with elevated serum creatine phosphokinase and myoglobin levels, the electromyogram was nonmyopathic, and polymyositis was confirmed by muscle biopsy. The case illustrates the value of anti-Jo-1 as a 'marker' autoantibody for polymyositis, and the need for thorough investigation of patients with interstitial lung disease of uncertain etiology. This should include indirect immunofluorescence using a dividing cell substrate and tests for antibodies to extractable tissue antigens. The need to completely evaluate patients with dermatopolymyositis is also emphasised.

Polymyositis presenting with respiratory failure

A 36-year-old woman presented with a 3-month history of increasing dyspnoea, culminating in respiratory failure due to paralysis of respiratory muscles. She required assisted ventilation. Subsequently, mild limb and neck weakness was noted. Muscle biopsy of the right vastus lateralis showed polymyositis. The patient died suddenly and the postmortem revealed polymyositis with predominant involvement of the diaphragm and intercostal muscles.

Dermatomyositis and rapidly progressive fibrosing alveolitis

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