Lupus-like eruption as the presenting sign of acute myeloblastic leukemia.

Cutaneous manifestations are often the presenting sign of internal malignancies. Up to 50% of patients with acute myeloblastic leukemia (AML) have skin findings. Connective tissue disease, particularly dermatomyositis and, rarely, lupus, have been reported as a paraneoplastic syndrome to various internal malignancies, but seldom with leukemias. We report the case of a middle-aged woman ultimately diagnosed with acute myeloblastic leukemia, who presented initially with a malar eruption, joint pains, and diffuse rash on the upper and lower extremities, with pathology consistent with lupus erythematosus and negative autoimmune serology. There are no prior reports of cutaneous lupus as the presenting sign of AML, and this case highlights the importance of considering paraneoplastic phenomena with presentations of connective tissue disease in older patients, especially with negative serology.

CD11b/CD18 mediates production of reactive oxygen species by mouse and human macrophages adherent to matrixes containing oxidized LDL.

Production of reactive oxygen species (ROS) and other proinflammatory substances by macrophages adherent to matrix proteins that contain or have been modified by oxidized LDL (oxLDL) may play an important role in atherogenesis. In vitro, human macrophages adhere to matrixes containing oxLDL via scavenger receptors and are signaled to produce ROS partly by interactions of the class B scavenger receptor (SR-B) CD36 with ligands on the matrix. In this report, we show that macrophages from mice genetically deficient in SR-A or CD36 adhered equally as well and produced equal amounts of ROS on interaction with matrix-associated oxLDL. In contrast, macrophages from mice genetically deficient in the CD18 chain of beta(2)-integrins produced insignificant amounts of ROS on interaction with oxLDL-containing matrixes, even though they adhered to these matrixes as efficiently as did macrophages from wild-type mice. Antibodies against CD18, CD11b, or EDTA, the last of which chelates divalent cations required for integrin function, had no effect on adhesion of normal mouse or human macrophages to matrixes containing oxLDL but almost completely inhibited ROS production by macrophages adherent to this matrix. Thus, CD11b/CD18 plays an important role in regulating production of ROS by mouse and human macrophages adherent to matrixes containing oxLDL. It may play a hitherto-unsuspected role in regulating macrophage signaling pathways involved in inflammation and atherogenesis.