Initial predictors of poor survival in myositis-associated interstitial lung disease: a multicentre cohort of 497 patients
The independent predictive factors for rapidly progressive lung involvement leading to death in patients with myositis are (in descending order of hazard ratio):
1) anti-MDA5 positivity
2) age at onset 60 and above
3) CRP > 10mg/L
4) pulse oximetry saturation < 95%.
More predictors of early death in myositis with lung involvement:
1) increasing lung involvement on serial imaging (especially of upper lobes)
2) hypocapnia < 34.5 mmHg (suggesting tachypnoea)
3) superimposed lung infection (notably PCP).
Risks for the latter are:
1) high dose corticosteroid use
2) combination immunosuppressants use
3) high intensity immunosuppression
4) male gender.