Copyright ©ERS Journals Ltd 2006 Interstitial lung diseases associated with amyopathic dermatomyositis1 Second Division, Dept of Internal Medicine, and 2 Dermatology, Hamamatsu University School of Medicine, Hamamatsu, Japan. CORRESPONDENCE: T. Suda, 1-20-1 Handayama, Hamamatsu, 431-3192, Japan. Fax: 81 534352354. E-mail: suda{at}hama-med.ac.jp Keywords: Amyopathic dermatomyositis, interstitial lung disease
Received: March 18, 2006
The aim of the present study was to clarify the clinical characteristics and prognosis of patients with interstitial lung disease (ILD) associated with amyopathic dermatomyositis (ILD-ADM). The study consisted of 14 consecutive patients with ILD-ADM. Patients were classified into two categories, acute/subacute and chronic forms, according to the clinical presentation of ILD. The clinical features, responsiveness to therapy, and prognosis between the two forms were compared. Nine ILD-ADM patients were categorised as the acute/subacute form, and five as the chronic form. Arterial oxygen tension was significantly lower in the acute/subacute ILD than chronic ILD patients. On high-resolution computed tomography, ground-glass opacities were frequently found in the two forms, but consolidation was more common in acute/subacute ILD than chronic ILD. Bronchoalveolar lavage analysis showed higher numbers of total cells and lymphocytes in acute/subacute ILD than chronic ILD. Histologically, the most common finding was nonspecific interstitial pneumonia in the two forms, while diffuse alveolar damage was only found in acute/subacute ILD. Acute/subacute ILD was generally resistant to therapy, while chronic ILD responded well. Notably, the mortality of acute/subacute ILD was much higher than that of chronic ILD (67 versus 0%, respectively). In conclusion, interstitial lung disease associated with amyopathic dermatomyositis includes two different forms, the acute/subacute and chronic forms, with distinct prognoses. Amyopathic dermatomyositis (ADM) is recognised as a distinct subgroup of dermatomyositis (DM) with the typical skin rash of classic DM, but without muscle involvement 16. Several studies have demonstrated that rapidly progressive interstitial lung disease (ILD) with a poor prognosis occurs in patients with ADM 712. These patients were often resistant to intensive therapy, such as high-dose corticosteroids plus immunosuppressive agents, resulting in fatal respiratory failure. In contrast, a recent report from Europe emphasised a favourable prognosis of ILD associated with ADM (ILD-ADM) among ILD associated with ADM, DM, and polymyositis (PM) 13. As ILD-ADM is a rare condition, its characteristics have not been fully clarified. In the present study, therefore, the current authors examined a series of patients with ILD-ADM and attempted to determine its clinical features and prognosis.
Patient selection The study consisted of 14 consecutive patients (one male, 13 female) diagnosed with ILD-ADM. The diagnosis of ADM was confirmed based on modified Euwer's criteria as follows: 1) characteristic dermatological manifestations of classic DM, including a heliotrope rash and Gottoron's papules; 2) no muscle weakness; and 3) no increases in serum muscle enzymes during the observation period. All the subjects were seen as inpatients or outpatients at institutions between 1985 and 2005.
ILD presentations
Data collection
HRCT
Bronchoalveolar lavage
Lung biopsy
Treatment and outcome
Statistical analysis
Clinical features and laboratory findings Clinical characteristics of patients with acute/subacute ILD-ADM and chronic ILD-ADM are shown in table 1
Laboratory findings are presented in table 2
HRCT findings HRCT images of the lung were available for 13 patients (eight acute/subacute and five chronic ILD) and the findings are summarised in table 3
BAL analysis BAL was performed in seven patients (four acute/subacute and three chronic ILD). Patients with acute/subacute ILD-ADM had a significantly higher number of total cell counts than those with chronic ILD-ADM (table 3
Pulmonary pathology
Treatment
In acute/subacute ILD-ADM, corticosteroids alone did not achieve a significant improvement. Cyclophosphamide had no therapeutic effect in any of the seven patients receiving it, and it was replaced with cyclosporine in five, although four subsequently died of respiratory failure. Cyclosporine was given to eight patients, but five died. Several recent studies reported that early administration of cyclosporine might improve the prognosis of acute ILD-ADM 11, 17. Thus, the duration between the start of corticosteroids and addition of cyclosporine, and the duration between onset of respiratory symptoms and the start of cyclosporine among survivors and nonsurvivors was compared. However, no significant differences were found between survivors and nonsurvivors (duration between the start of corticosteroids and addition of cyclosporine 26.7±29.0 versus 19.0±20.1 days; duration between onset of respiratory symptoms and the start of cyclosporine 66.7±55.3 versus 42.5±47.6 days, respectively). Three patients with acute/subacute ILD-ADM were treated with high-dose corticosteroids plus cyclosporine very early in the course of ILD, but two died of respiratory failure. Intravenous immunoglobulin therapy was effective in one patient that showed resistance to corticosteroids plus cyclosporine. In chronic ILD-ADM, corticosteroids alone were given to one patient, who showed improvement. Cyclosporine was given to three patients. Two of them received cyclosporine plus corticosteroids initially with a favourable response, while the other patient was given cyclosporine as a corticosteroid-sparing agent after the start of corticosteroid therapy. The duration of therapy was longer in chronic than acute/subacute ILD-ADM.
Mortality and survival
In the present study, the authors retrospectively reviewed consecutive cases of ILD-ADM and attempted to elucidate its clinical characteristics and prognosis. It was found that ILD-ADM includes two different forms, acute/subacute and chronic, each with distinct prognoses. Acute/subacute ILD-ADM, which rapidly progressed, showed poor response to therapy and had high mortality. In contrast, chronic ILD-ADM responded well to therapy with a favourable prognosis. As ADM is a rare disease, previous studies of ILD-ADM included only one, or a few patients 713. The present study investigated the highest number of patients with ILD-ADM so far. To date, contradictory data have been reported in the prognosis of ILD-ADM. Previous studies, mainly from Asia, have demonstrated that ILD-ADM generally runs an aggressive course, leading to fatal respiratory failure 712. In contrast, Cottin et al. 13 recently described a benign form of ILD-ADM. They reported three patients with chronic ILD-ADM, and corticosteroids alone achieved a favourable response in two. The other one responded well to corticosteroids plus immunosuppressive agents. None of these three patients died during the observation period, leading to the conclusion that ILD-ADM has a good prognosis. In the present study, it was demonstrated that ILD-ADM consisted of at least two different forms with distinct outcomes. Acute/subacute ILD, which constituted about two thirds of the ILD-ADM patients, showed a rapid progression that was poorly responsive to therapy, resulting in severe respiratory failure. Conversely, chronic ILD-ADM showed a mild course and responded well to therapy. Notably, the outcome was completely different between these two forms. The mortality was much higher in patients with acute/subacute ILD-ADM (67%) than those with chronic ILD-ADM (0%). In acute/subacute ILD-ADM, no patients had chronic respiratory symptoms before ILD diagnosis. Additionally, in patients developing acute/subacute ILD after ADM diagnosis, no abnormality was found on HRCT at the initial ADM diagnosis. These data suggest that chronic ILD is unlikely to pre-exist in the study patients with acute/subacute ILD. Taken together, these results may account for the contradictory data previously reported in the prognosis of ILD-ADM. Namely, the fatal progressive ILD-ADM described is likely to correspond to the acute/subacute ILD-ADM in the present study, while the ILD-ADM with a favourable prognosis reported by Cottin et al. 13 may be equivalent to chronic ILD-ADM. Although ethnic differences may affect the clinical manifestations of ILD-ADM, it should be noted that ILD-ADM has these two different forms. In a comparison of the clinical characteristics between acute/subacute ILD-ADM and chronic ILD-ADM, ILD onset was concomitant with ADM in all the patients with acute/subacute ILD-ADM except one, while more than half of patients with chronic ILD-ADM developed ILD after an ADM diagnosis. In addition, extrapulmonary symptoms, including fever and arthralgia, were more common in acute/subacute ILD-ADM than chronic ILD-ADM. Pa,O2 and %VC were significantly lower in acute/subacute ILD-ADM than chronic ILD-ADM. These data suggest that patients with acute/subacute ILD-ADM, which commonly occur simultaneously with ADM onset, have more severe ILD with systemic symptoms at the initial examination than those with chronic ILD. Regarding the anti-Jo-1 antibody, only one patient with chronic ILD-ADM had this antibody among the present ILD-ADM study. To date, several studies have reported a low incidence of anti-Jo-1 antibody in ILD-ADM patients 1113, 1719. The current results were consistent with those studies. There have been few reports of the HRCT findings of ILD-ADM 7, 13, 20. According to these reports, ground-glass opacities, consolidation and irregular linear opacities were often seen in ILD-ADM. Consistently, the study patients with ILD-ADM had a high frequency of these findings on HRCT. Notably, ground-glass opacities were found in all the patients. Between the two forms, consolidation was more common in acute/subacute ILD-ADM, while traction bronchiectasis was more frequently found in chronic ILD-ADM. Honeycombing was seen in only one patient with chronic ILD-ADM, who was histologically proven to have UIP. Overall, 60% of ILD-ADM patients with NSIP histology had consolidation. Originally, consolidation was reported not to be a common finding in idiopathic NSIP 21, 22. In ILD-PM/DM, however, much higher prevalence of consolidation was demonstrated in NSIP 23, 24. A recent study showed that consolidation was found in 42.9% of NSIP patients associated with PM/DM 23. In addition, a previous study indicated that 86% of NSIP patients associated with PM/DM showed consolidation 24. These data suggest that consolidation is more common in NSIP associated with PM/DM/ADM than in idiopathic NSIP. To date, little is known about the BAL findings of ILD-ADM. Two reports from Japan demonstrated an increase of BALF lymphocytes and neutrophils in acute/subacute ILD-ADM 11, 12. The present study showed that the BAL findings differed between the two forms. Patients with acute/subacute ILD-ADM had an increase in percentages of BALF lymphocytes, as well as neutrophils, while those with chronic ILD-ADM showed only a moderate increase in percentages of BALF neutrophils. In addition, the total cell counts were significantly higher in acute/subacute than chronic ILD-ADM. Interestingly, the CD4/CD8 ratio of BALF T-lymphocytes tended to be higher in acute/subacute ILD-ADM than chronic ILD-ADM. Inconsistent with the current data, Yokoyama et al. 12 recently reported a case of fatal acute ILD-ADM with a low CD4/CD8 ratio (0.2) of BALF T-lymphocytes. However, none of the present patients with acute/subacute ILD-ADM exhibited <1.0 CD4/CD8 ratio; the reason for this discrepancy is unknown. Further studies including larger numbers of patients may elucidate this point. Several studies on the histopathology of ILD-PM/DM have demonstrated various histological patterns, such as UIP, NSIP, BOOP and DAD, and emphasised their prognostic significance 13, 2527. However, limited data are available on the histopathology of ILD-ADM. Lee et al. 7 recently reported three cases of acute ILD-ADM with a histological finding of DAD, which was associated with poor outcome; whilst Cottin et al. 13 described three patients with chronic ILD-ADM who showed NSIP with a good prognosis 13. Based on these observations, acute/subacute ILD-ADM and chronic ILD-ADM might histologically correspond to DAD and NSIP, respectively. In the present study, however, NSIP was found in three out of five patients with acute/subacute ILD-ADM, of which two responded to therapy and survived, while the third patient died despite intensive therapy. The remaining two with acute/subacute ILD-ADM had DAD, and all died within 2 months. More recently, Miyazaki et al. 11 reported three patients with rapidly progressive ILD-ADM, and of these, NSIP was found in two and DAD in one. In addition, Sakamoto et al. 10 described a case of fatal ILD-ADM with a histological finding of NSIP. Taking the current data together with recent studies, the histological patterns of acute/subacute ILD-ADM include NSIP in addition to DAD. Conversely, the study patients with chronic ILD-ADM showed UIP and NSIP, but not DAD. Possibly, the favourable prognosis of chronic ILD-ADM was partially associated with the fact that no DAD was found in those patients. The optimal treatment for patients with ILD-ADM has not been established because of its rarity. Recent studies of rapidly progressive ILD-ADM have highlighted the effectiveness of cyclosporine combined with corticosteroids in the early course of ILD 11, 17. Among the current acute/subacute ILD-ADM study, eight out of the nine patients received cyclosporine, although five of whom subsequently died of respiratory failure with a poor response to therapy. Between survivors and nonsurvivors, no difference was found in the duration between the start of corticosteroids and addition of cyclosporine, or the duration between onset of respiratory symptoms and the start of cyclosporine. In addition, two acute/subacute ILD-ADM patients receiving corticosteroids plus cyclosporine together during the very early course of ILD failed to respond. Collectively, these results suggest that early administration of cyclosporine may be beneficial in certain patients with acute/subacute ILD-ADM, but not in all. Interestingly, intravenous immunoglobulin therapy was effective in one patient with acute/subacute ILD that was resistant to corticosteroids plus cyclosporine. More recently, Tsukamoto et al. 28 reported the efficacy of autologous peripheral blood stem cell transplantation in a patient with ILD-ADM that was unresponsive to corticosteroids plus cyclosporine. To date, however, there is no concrete evidence of treatment for ILD-ADM. Thus, future investigations are needed to elucidate an effective therapy for acute/subacute ILD-ADM. In chronic ILD-ADM, all four of the study patients had good outcomes. Interestingly, corticosteroids alone achieved a favourable response in one patient. Three patients received cyclosporine plus corticosteroids, which proved to be effective. However, it remains to be determined whether immunosuppressive therapy is actually required for chronic ILD-ADM patients. Recently, the current authors reported the characteristics of patients with ILD-PM/DM and highlighted the differences in clinical features and prognosis between ILD-PM and ILD-DM 24. ILD-DM was shown to be more refractory to therapy, resulting in poorer prognosis than ILD-PM. Compared with ILD-DM/PM, the survival curve of overall ILD-ADM patients tended to be worse than that of ILD-DM patients without a significant difference, and significantly worse than that of ILD-PM patients (data not shown). In terms of clinical presentation, acute/subacute forms were found in 35 and 47% of ILD-PM and ILD-DM patients, respectively. Thus, the proportion of acute/subacute form was highest in ILD-ADM patients (64%). Interestingly, none of the study patients developed ILD before ADM onset, regardless of acute/subacute or chronic form. To date, only two cases have been reported in which ILD onset preceded ADM 13, whilst, in all other cases, reported ILD onset was concomitant with, or followed ADM 712. In ILD-PM/DM, however, 2030% of patients have been reported to develop ILD before PM/DM diagnosis 27, 29. Indeed, a previous study of ILD-DM/PM by the current authors demonstrated that ILD onset preceded diagnosis of PM/DM in 19% of ILD-PM patients and in 33% of ILD-DM patients 24. Thus, a low proportion of patients in which ILD onset precedes collagen vascular diseases may be one of the clinical characteristics of ILD-ADM. Collectively, these data suggest that ILD-ADM, which is more likely to take an acute/subacute course and not to precede ADM, has the poorest prognosis among ILD associated with DM, PM and ADM. In conclusion, the present study demonstrated two different forms of interstitial lung disease associated with amyopathic dermatomyositis, acute/subacute and chronic forms, which were closely related to outcome. In order to appropriately care for patients with interstitial lung disease associated with amyopathic dermatomyositis, these two conditions should be taken into account. Further studies will provide information regarding the optimal treatment for patients with acute/subacute and chronic interstitial lung disease associated with amyopathic dermatomyositis.
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||