Pleuritis, pulmonary hypertension and shrinking lung syndrome have all been associated with systemic lupus erythematosus but a new study of lupus-associated ILD highlights some of the academic and clinical challenges of rare complications.
A French study has found that while indeed rare, ILD in lupus was a major independent risk factor for death.
The study of 37,393 lupus patients with at least one hospital stay during the study period found 1.2% had an ILD diagnosed at baseline in 2011-2012.
Of the remaining patients, 2.6% were diagnosed with an ILD between 2013 and 2020.
The study, published in Respirology, said the incidence rate of ILD in SLE overall was 10.26 for 1000 patient-years (95% CI 10.24–10.28).
It found ILD was significantly associated with an increased risk of death in SLE patients (HR [95% CI] 1.992 [1.420–2.794]; p < 0.0001).
“Although ILD was considered to have a limited impact on global outcome in previous reports, it is independently associated with a premature death in our study, with an HR similar to chronic kidney disease in SLE.”
The study found risk factors for ILD in lupus were older age (55 [44–64] vs. 44 [33–58] years; p < 0.0001) and male gender (20.9% vs. 13.4%; p = 0.012).
“Interestingly, the frequency of ILD in SLE was higher in patients who had another autoimmune disease – such as Sjögren’s syndrome or systemic sclerosis – associated with SLE (29.9% vs. 5.9%; p < 0.0001),” it said.
The study was unable to determine if any ILD pattern such as non-specific interstitial pneumonia, usual interstitial pneumonia, organising pneumonia, diffuse alveolar damage and/or lymphocytic interstitial pneumonia was specifically associated with SLE.