CALR and systemic lupus erythematosus: However, there are distinguishing features that may help differentiate between the two entities, including the presence of malar rash, the type of pulmonary involvement (obstructive in HUV versus restrictive in SLE), and laboratory markers such as anti-dsDNA, anti‐Sm, anti‐Ro/SSA, and anti‐La/SSB antibodies, which are more indicative of SLE.