Takeaway
Pulmonary hypertension (PH), pericarditis and glomerulonephritis occur in patients with anti-U1-ribonucleoprotein (RNP) autoantibodies with coexisting anti-Ro52 autoantibodies but are rare in other myositis groups.
Why this matters
Testing for anti-Ro52 in patients with anti-U1-RNP-positive myositis might help identify those who are at risk of developing serious extramuscular manifestations.