h. L.E. Cells.
(1) Persons having lupus erythematosus, one of the "collagen" diseases,
have an abnormal; plasma protein that causes swelling and breakdown of certain blood
cell nuclei in vitro. This degenerated nuclear material attracts phagocytic cells,
particularly segmented neutrophils, which engulf this nuclear mass. The resulting
phagocyte and inclusion material is termed an "L.E." cell.
(2) The nucleus of an L.E. cell is adjacent to the peripheral outline of the
inclusion material. The inclusion is smooth and silky or light purple and has no visible
Figure 4-7d. Variations in leukocytes: L.E. Cells.
i. Rosettes. Rosette formation is the intermediate stage in the formation of an
L.E. cell. A rosette formation consists of neutrophilic leukocytes surrounding free
masses of lysed nuclear material.
j. Tart cells. A tart cell, which may be confused with the L.E. cell, contains
lysed nuclear material within its cytoplasm. It differs from an L.E. cell because the
inclusion retains characteristic nuclear structure. This inclusion is not smooth and has a
darker staining periphery. The significance of tart cells is not known but their presence
in an L.E. preparation does not signify a positive test for systemic lupus erythematosus.
Section IV. THROMBOCYTES
a. The general pattern of thrombocyte maturation is slightly different from that of
leukocyte maturation. The cells of the megakaryocytic series tend to grow larger as
they mature until there is cytoplasmic fragmentation (or breaking off) to form the
cytoplasmic thrombocytes seen in the peripheral blood.
b. Azurophilic granulation begins to appear in the second stage of development
and continues until it almost obscures the nuclear lobes. The nucleus develops from a
fine single lobe to multiple ill-defined lobes. The stages in the normal maturation of the
megakaryocytic series are: megakaryoblast, promegakaryocyte, megakaryocyte, and