Xie et al reported risk factors for mortality in patients with dermatomyositis positive for anti-MDA5 antibodies. The authors are from the Chinese Academy of Medical Sciences and Peking Union Medical College in China.
Patient selection: dermatomyositis, positive for anti-MDA5 antibodies
Risk factors for mortality:
(1) older age (> 50 years of age; HR 1.5)
(2) male sex (HR 2.1)
(3) rapidly progressive interstitial lung disease (HR 9.3)
(4) elevated serum ferritin concentration (HR 1.05)
(5) elevated serum CRP concentration (HR 1.12)
(6) elevated serum creatine kinase (> 100 U/L; HR 1.05)
(7) elevated serum LDH activity (> 400 IU/L; HR 1.3)
Factors associated with more favorable outcomes:
(1) oxygen index (HR 0.99)
(2) partial pressure of oxygen (HR 0.93)
(3) forced vital capacity (HR 0.96; FVC < 50% associated with worse prognosis in Figure 2)
(4) absolute lymphocyte count (HR 0.42; lymphopenia might be viewed as a poor prognostic finding)
where:
• Hypoxemia (see favorable factors #1 and #2) would be a poor prognostic factor.
• Not all interstitial lung disease would be rapidly progressive. The first 3 favorable findings would be affeced by ILD.