Double anti-PL-7 and anti-MDA-5 positive Amyopathic Dermatomyositis with rapidly progressive interstitial lung disease in a Hispanic patient

Abstract

Background: Each myositis-specific autoantibody (MSA) tends to have a distinct clinical presentation. Coexistence of MSAs do not commonly occur. If they do, it is unknown if there is an overlap of clinical features or prognostic implications. There are a few reported cases of overlap between these antibodies, mostly reported in patients with Japanese descent. Our aim for this case report is to turn more attention and interest for future MSA profile studies in the Hispanic population, which may hopefully spur better therapies if we realize the prognostic implications of certain myositis subsets including double-positive autoantibody syndromes. Case presentation: A 27-year-old Hispanic female was admitted to the medical intensive care unit due to acute hypoxemic respiratory failure secondary to acute respiratory distress syndrome (ARDS). She had failed conventional mechanical ventilation and was cannulated for venovenous extracorporeal membrane oxygenation (VV-ECMO) to manage her respiratory failure. She had erythematous scaly plaques on bilateral 3rd metacarpophalangeal joints on examination. Her autoimmune workup revealed positivity for both anti-PL-7(threonyl) and anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies. After extensive evaluation, it was concluded that she had rapidly progressive interstitial lung disease (RPILD) due to amyopathic dermatomyositis. Despite maximal medical management, she was ultimately transitioned to comfort care measures and expired. Conclusion: We would like to highlight the rarity of double antibody positive amyopathic dermatomyositis. This unique clinical presentation has only been reported in persons of Japanese descent. Our case is likely to be the first reported to occur in a person of Hispanic descent in the United States. The rarity of our case could stimulate further study of overlapping MSA to understand its varied presentations and prognoses including possible tendency toward a rapidly progressive ILD phenotype. Earlier detection of these clinical syndromes can lead to better outcomes for patients with RPILD. This case report could also herald an increased recognition and understanding of MSA profile in the Hispanic population in the USA.

Clinically amyopathic dermatomyositis with interstitial lung disease double-positive for anti-MDA5 and anti-PL12 antibodies

“…However, the pathogenesis and clinical features of double-positive MSAs in DM-ILD are unclear because of the rarity of this condition. To date, only four cases of DM/CADM-ILD with anti-ARS and anti-MDA5 antibody double-positive, including our case [ [9] , [10] , [11] ], have been reported ( Table 2 ). MAAs were detected in two patients.…”

“…This case may indicate that macrophage activation is reduced or blocked by some mechanisms in some certain patients with anti-MDA5 antibody-positive DM/CADM-ILD together with anti-ARS antibody. In contrast, another Hispanic patient died of acute respiratory failure due to DM-ILD [ 11 ]. Therefore, whether the clinical course presents as ARS-ILD, MDA5-ILD, or their combination remains unclear.…”

“…These antibodies tend to differ in their pathophysiological profiles and clinical presentations [ [3] , [4] , [5] , [6] , [7] , [8] ]. The coexistence of these MSAs is very rare, and only a few such cases have been reported [ [9] , [10] , [11] ]. Here, we describe a rare case of clinically amyopathic dermatomyositis (CADM) associated with interstitial lung disease (ILD) with coexisting anti-PL12 and anti-MDA5 antibodies.…”

Coexistence of Multiple Myositis-Specific Antibodies in Patients with Idiopathic Inflammatory Myopathies

“…Our results did not go against the notion that the presence of MSAs was essentially mutually exclusive in IIM [ 13 ]. The coexistence of two MSAs in an IIM patient is rare but does exist [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…The mutual exclusivity of MSAs has been reported before [ 13 ], which made the serology tests for MSAs more crucial for IIM subtyping. However, the coexistence of 2 or more MSAs was still found in a few case reports [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”