Anti‐MDA‐5 antibody‐positive clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease treated with therapeutic plasma exchange: A case series

Abstract

We present six cases of antimelanoma differentiation-associated gene 5 antibody (anti-MDA5-Ab)-positive clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial lung disease (RP-ILD), which is known to have a poor prognosis. The outcomes of these cases are described after treatment with therapeutic plasma exchange (TPE). Clinical and therapeutic data for patients with CADM with RP-ILD were collected retrospectively from medical records. All six patients received early intensive care including high-dose corticosteroids, intravenous cyclophosphamide, and a calcineurin inhibitor, but lung disease and hypoxia became more severe. TPE was performed over a median of 9.5 sessions (range 3-14) per patient, and the median duration from admission to TPE was 23 days. Three patients received combined direct hemoperfusion using a polymyxin B-immobilized fiber column (PMX-DHP) therapy on successive days to manage acute respiratory failure. Four patients survived and two died due to respiratory failure. In the survival cases, ferritin decreased, and ferritin and KL-6 were lower at diagnosis. The patients who died had a higher alveolar-arterial oxygen difference and more severe lung lesions at the time of initiation of TPE. These findings indicate that a combination of conventional therapy and TPE may be useful for improvement of the prognosis of CADM with RP-ILD at the early stage of onset.

Successful Treatment of Anti-MDA5 Antibody-Positive Dermatomyositis-Associated Rapidly Progressive-Interstitial Lung Disease by Plasma Exchange: Two Case Reports

“…The third question is how long PE should be continued for the patients with anti-MDA5 antibody-positive DM-associated RP-ILD. Regarding the total number of PE sessions, the average number of PE was 9.5 to 11.4 sessions in the previous reports, 10 , 11 which was much less than the present cases (24 sessions for Case 1 and 31 sessions for Case 2). In clinical practice, once PE is started, it is often difficult to decide the timing of the termination of PE treatment due to the high mortality rate of the disease.…”

“…The next question is when to start PE. According to the previous report, 11 the duration from the diagnosis to the start of PE was 11.5 days, which was much shorter than the present cases (5 weeks for Case 1 and 12 weeks for Case 2). In addition, in patients with anti-MDA5 antibody-positive DM-associated RP-ILD, early initiation of treatment has been reported to be one of the prognostic factors.…”

“…PE has been recommended for the patients who are refractory to the immunosuppressive therapy, and several cases have been reported to respond to PE successfully. 3 , 6 - 11 Moreover, the results of previous studies showed that PE significantly provided the higher survival rate for the patients who were refractory to immunosuppressive therapy. 3 , 10 Abe et al 3 showed that in patients refractory to immunosuppressive drugs, the 1-year survival rate of the PE group was significantly higher than that of the non-PE group (100% and 25%, respectively, P = .033).…”

“…In addition, in patients with anti-MDA5 antibody-positive DM-associated RP-ILD, early initiation of treatment has been reported to be one of the prognostic factors. 11 Moreover, it takes about 2 weeks for cyclophosphamide, the key drug in the 3-drug combination therapy, to exert its effect. Since PE reduces the titer of autoantibodies immediately, the early initiation of PE may be a useful option until the effect of cyclophosphamide is achieved.…”

“… 4 , 5 Several case reports have described successful PE treatment for the patients with anti-MDA5 antibody-positive DM-associated RP-ILD in recent years. 3 , 6 - 11 However, as yet, standard protocols for the initiation/termination timing and the frequency of PE have not been established for these patients. Here, we present 2 cases of anti-MDA5 antibody-positive DM-associated RP-ILD for which PE was successfully executed.…”