What is a lupus erythematosus cell?
An Lupus erythematosus cell (LE cell) is a neutrophil that has engulfed the intact nucleus of another cell. It was first discovered in 1948 by Hargraves and colleagues at the Mayo Clinic on inspection of bone marrow biopsies among 25 patients with SLE. It is now understood that an LE cell represents the end result of ANAs binding to a nucleus and fixing complement resulting in phagocytosis by a neutrophil. LE cells have been reported in the synovial fluid as well as pleural and pericardial effusions in patients with SLE, but are uncommonly found in undisturbed peripheral blood. To identify LE cells, a peripheral blood sample must be disrupted, incubated for a period of time, and then inspected (the LE cell prep). This was the major method of measuring ANAs in the 1950s and 1960s. This test is time consuming and relatively insensitive in detecting ANAs (70%–80%) compared with IIF and is no longer commonly performed.