Risk factors for development of interstitial lung disease (ILD)
| Demographic | Clinical | Serologic | |
| RA | Older age# Older age of RA onset# Male sex# Female sex# Longer RA duration Shorter RA duration# | Morning stiffness Erosive arthritis DAS28 score# BMI >30 kg·m−2# Smoking history# | RF positive# RF titre# Anti-CCP positive# Anti-CCP titre# ESR# CRP LDH# |
| SSc | Older age Male sex Female sex Black race# Longer SSc duration# Shorter SSc duration | Diffuse cutaneous subtype# Higher MRSS Digital ulcers# History of renal crisis GI system involvement# Myopathy Ever smoker (lower ILD) | Anti-Scl70# Anti-centromere absent# Anti-SSA positive ESR# CRP Hb <13.0 g·dL−1 |
| Idiopathic inflammatory myositis | Black race | Polymyositis (lower ILD) Anti-synthetase syndrome Clinically amyopathic Mechanic's hands# Absence of malignancy Arthralgia/arthritis Lateral hip erythema# | Anti-synthetase antibody Anti-Jo1 Anti-PL7/12 Anti-MDA5# ANA Anti-SSA Anti-Ro52 Anti-NXP2, Tiff, Mi2 (lower ILD) ESR# CRP Lower Hb |
| Primary Sjögren syndrome | Older age# Older age of onset Male sex# Longer disease duration | Raynaud's phenomenon Oral ulcer Salivary gland biopsy focus score ≥4# | ANA Anti-SSA Anti-SSB Anti-Ro52 ANCA positive ESR CRP |
| Mixed connective tissue disease | Raynaud's phenomenon# Dysphagia# Never arthritis | Anti-U1 RNP >200 |
All risk factors are reported as the state associated with an increased risk of ILD (e.g. “Older age” indicates higher ILD prevalence with older age). Some studies reported opposite effects (e.g. male and female sex were each identified as a risk factor for ILD in different studies of rheumatoid arthritis (RA)). Insufficient data were available for systemic lupus erythematosus and undifferentiated connective tissue disease. Italic: ≥5 studies. #: adjusted analysis. ANA: antinuclear antibody; ANCA: antineutrophil cytoplasmic antibody; BMI: body mass index; CCP: cyclic citrullinated peptide; CRP: c-reactive protein; DAS: disease activity score; ESR: erythrocyte sedimentation rate; GI: gastrointestinal; Hb: haemoglobin; LDH: lactate dehydrogenase; MDA5: melanoma differentiation-associated gene 5; MRSS: modified Rodnan skin score; RF: rheumatoid factor; RNP: ribonucleoprotein; SSA/B: Sjögren's syndrome type A/B; SSc: systemic sclerosis.