Qualitative Defects of White Cells PDF

QUALITATIVE DEFECTS OF WHITE CELLS ▪ Qualitative changes of the WBC take place either in the cytoplasm or the nucleus; inherited or acquired. ▪ Toxic changes of the WBCs occur due to stress during maturation and as a result of activity in the circulation or tissue. Toxic Changes in White Ce...

QUALITATIVE DEFECTS OF WHITE CELLS ▪ Qualitative changes of the WBC take place either in the cytoplasm or the nucleus; inherited or acquired. ▪ Toxic changes of the WBCs occur due to stress during maturation and as a result of activity in the circulation or tissue. Toxic Changes in White Cells As white cells increase, what is usually seen in the peripheral smear is either 1. an increase in the number of segmented neutrophils giving rise to a neutrophilia or 2. a shift to the left, where younger cells are noted. ▪ In either of these cases, toxic changes such as toxic granulation, toxic vacuolization, or the presence of Döhle bodies may be observed. Toxic Granulation ▪ Toxic granulation is excessive granulation in amount and intensity, with more prominent granules in segmented neutrophils in direct response to enhanced lysosome enzyme production. Toxic granulation. ▪ These granules are more frequent and have much more vivid blue-black coloration. Toxic Vacuolization ▪ This change occurs in segmented neutrophils; vacuoles appear in the cytoplasm of this cell and may be small or large. ▪ Larger vacuoles unevenly distributed throughout the cytoplasm usually signal serious infections Toxic vacuolization. and possible sepsis. Döhle Bodies ▪ These cytoplasmic inclusions consist of ribosomal RNA. ▪ They range from 1 to 5 μm in size, are located near the cytoplasmic membrane, and appear as a rod-shaped pale bluish- gray structure. ▪ They are frequently observed in neutrophils but may be seen in monocytes and bands. ▪ Döhle bodies may also be seen in Döhle bodies pregnancy. Nuclear Abnormalities: Hypersegmentation ▪ Hypersegmentation is defined as a segmented neutrophilic nucleus having more than five lobes. ▪ This condition is usually seen in the megaloblastic processes such as folic acid, pernicious anaemia, or vitamin B12 deficiency and is usually Hypersegmented neutrophil accompanied by oval macrocytes. Pyknotic Nuclei ▪ Pyknotic nuclei in neutrophils generally indicate imminent cell death. ▪ In a pyknotic nucleus, nuclear water has A been lost and the chromatin becomes very dense and dark; however, filaments can still be seen between segments. ▪ Pyknotic nuclei should not be confused with necrotic nuclei found in dead cells. B ▪ Necrotic nuclei are rounded fragments of A, Upper cell is a neutrophil whose nucleus is nucleus with no filaments and no dehydrated, which makes it very dark and dense. Note that there is still a filament chromatin pattern. between the segments. This is referred to as a pyknotic cell. The cell is also highly vacuolated. B, Neutrophil that has died. Note that the nucleus has disintegrated into numerous rounded spheres of DNA with no filaments. This is referred to as a necrotic or necrobiotic cell. Degranulation ▪ Degranulation is a common finding in activated neutrophils and eosinophils. ▪ Both primary and secondary granules are emptied into phagosomes, and secondary granules are also secreted into the extracellular space. Partially degranulated eosinophil. This cell was found on the blood film for a patient with ▪ In vitro degranulation in eosinophils trichinosis. often occurs when cellular membranes are disrupted during the process of making the blood film; eosinophils are fragile. Cytoplasmic swelling ▪ Cytoplasmic swelling may be caused by actual osmotic swelling of the cytoplasm or by increased adhesion to the glass slide by stimulated neutrophils. ▪ Regardless of the cause, the result is a Neutrophil anisocytosis. The neutrophil to the variation in neutrophil size or neutrophil left is larger than the other neutrophil. This is often caused by cytoplasmic swelling. anisocytosis. Reactive Morphologic Changes in Neutrophils Reactive Change Morphology Associated with Toxic granulation Dark, blue-black cytoplasmic granules Inflammation, infection, administration of granulocyte colony stimulation factor (G- CSF) Dohle bodies Intracytoplasmic pale blue round or Nonspecific finding, or associated with elongated bodies between bacterial infections, sepsis, and 1 and 5 μm in diameter, usually adjacent pregnancy to cellular membranes. Cytoplasmic vacuolization of neutrophils Small to large circular clear areas in Septicemia or other infection; cytoplasm, rarely may contain autophagocytosis secondary to drug organism ingestion, acute alcoholism, or storage artifact; vacuoles are sometimes seen in conjunction with toxic granulation. END