Background/Purpose: The necessity of intensive combination immunotherapy for all patients with anti-MDA5 ILD is debated, given the variable progression of the disease, risk of infection and mixed effectiveness of treatments. Although several risk factors identified for RPILD, patient may be presented at different stage of ILD, challenging outcome prediction and therefore treatment strategy.

Methods: Patients with idiopathic inflammatory myositis or rapid progressive interstitial pneumonia and positive anti-MDA5 antibody at National Taiwan University from 2014 to 2024 were enrolled. To evaluate disease trajectories in patients presented with different ILD stage, patients were divided in three groups according to their ILD condition at diagnosis: (1) No or subclinical ILD (defined as < 10% parenchymal involvement on CT and no respiratory symptoms). (2) Clinical ILD (defined as >10% involvement in CT, presence of respiratory symptoms, not requiring > 5 L/min O2 supplement). (3) Ongoing respiratory failure (extensive involvement in CT and requiring > 10 L/min O2 supplement or intubation). 

Results: Thirty-seven patients were enrolled and grouped by their ILD status at daignosis (Table 1). Patients who presented with ongoing respiratory failure had 3-month survival 31%, while patients presented with subclinical ILD or clinical ILD had significantly better 3-month and 6-month survival (Figure 1). In patients who presented with RPILD (n=13) or who progressed during follow-up (n=10), there were two specific CT patterns of progression identified: newly developed upper lung GGOs or peribronchovascular consolidation (Figure 2). Patient who died (15/23, 65%) had concomitant anti-Ro-52 (100% vs 0%, p=0.007), newly developed upper lung GGOs at CT (92 vs 38%, p=0.014), higher CRP level ( >0.4mg/dL, 100% vs 57%, p=0.02) and shorter time from initial to worsening respiratory symptoms (1.7 vs 3.3 months, p=0.06). Among patients with no or subclinical ILD at diagnosis, there were still 31% (5/16) patients had rapid-progressive ILD (RPILD). Those without progression (71%) were younger (mean age 46 vs. 55), with lower baseline serum ferritin (667 vs 1053) and CRP level (0.1 vs 1.8 mg/dL, p=0.03), and a longer duration of non-respiratory symptoms before diagnosis (2.2 vs 1.0 months, p=0.04).

Conclusion: Outcomes for those presenting with respiratory failure at diagnosis remain poor, particular in patients with concomitant anti-Ro52 and specific CT pattern at progression, highlighting the unmet need of current treatment. Patients presented without ILD or having subclinical ILD still had risk of RPILD, but younger patients with longer non-respiratory symptom duration (e.g, > 3 months) and low ferritin and CRP level, may remain stable without progression. Tailored immunotherapy regimen may be required based on the ILD status at presentation and individualized risk assessment.

« Back to ACR Convergence 2024

ACR Meeting Abstracts - https://acrabstracts.org/abstract/disease-trajectory-in-anti-mda5-dermatomyositis-patients-presented-with-different-stage-of-interstitial-lung-disease/