Page 244 - Haematologica Atlas of Hematologic Cytology

Figure . ongenital neutropenia. A 7-month-old infant presented with relapsing infectious epi- sodes: at five months a parotid abscess, and at six months an episode of gingival necrosis. Phy- sical examination revealed nothing worthy of note. Blood count showed mild anemia, throm- bocytosis and leukocytosis with monocytosis, eosinophilia and complete absence of circulating neutrophils. Peripheral blood smear shows hypo- chromic microcytes, many normal platelets, and two lymphocytes.
Figure . ongenital neutropenia. Bone marrow smear from the same case as in Figure 5. Hyper- plasia of the granulocytic lineage, which is repre- sented at early and intermediate levels of diffe- rentiation. Late cells are reduced or absent. Note also the modest signs of dyserythropoiesis. Isola- ted congenital neutropenia may be severe (with high susceptibility to infection) or mild (with a favorable clinical course). It can also be cyclical. Approximately 90% of cases with severe conge- nital neutropenia respond to granulocyte colony stimulating factor therapy. If there is no response to growth factor therapy, the only effective treat- ment is hematopoietic stem cell transplantation.
Figure . ongenital neutropenia. The same bone marrow smear as in Figure 6 shows maturation arrest of the granulocytic lineage with very rare elements beyond the myelocytic stage. In most cases, congenital neutropenia results from a mu- tation in ELANE, the gene encoding neutrophil elastase. The mutant ELANE protein triggers ac- celerated apoptosis of developing neutrophil pre- cursors.
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