MEK1/2‐ and ERK1/2‐Mediated Lung Endothelial Injury and Altered Hemostasis Promote Diffuse Alveolar Hemorrhage in Murine Lupus

About 3% of patients with lupus develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. C57BL/6 (B6) mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of Toll-like receptor signaling and other inflammatory pathways. This study examined the role of the MEK1/2 pathway (MEK1/2-ERK1/2, JNK, p38).