Page 997 - Williams Hematology ( PDFDrive )

972 Part VII: Neutrophils, Eosinophils, Basophils, and Mast Cells Chapter 63: Basophils, Mast Cells, and Related Disorders 973

TABLE 63–3. Leukemias Associated with Basophilia tissue mast cells has been reported. Studies of small numbers of patients
indicate that certain mast cell populations, namely, the MC mast cells
T
Chronic myelogenous leukemia with exaggerated basophilia in the gastrointestinal mucosa, can be strikingly reduced in numbers
Blast transformation, including acute basophilic transformation, in subjects with genetically determined or acquired (HIV-induced)
159
of chronic myelogenous leukemia immunodeficiency. Human mast cell precursors can be infected in
Acute myelogenous leukemia with t(9;22), t(6;9), t(3;6) or 12p vitro with so-called M tropic strains of HIV 90,91,93 ; and in vivo may com-
92
abnormalities and marrow basophilia prise a long-lived inducible reservoir of persistent HIV. Whether mast
Acute basophilic leukemia with t(X;6)(p11.2;q23.3); MYB-GATA1 cell infection with HIV contributes to the reduction in gastrointestinal
mast cells observed in some subjects with HIV infection remains to be
“Acute basophilic leukemia” determined.
A number of disorders are associated with small to up to several
fold increases in mast cell numbers in or near the tissues affected by the
of a CD123-positive, CD203c-positive, and CD117-negative blast disorder (Table 63–4). Tissues at sites of recurrent allergic reactions often
cell immunophenotype may be useful in making a diagnosis of acute exhibit increases in mast cell numbers, to levels as high as approximately
basophilic leukemia. The best defined entity of acute basophilic leu- fourfold normal. 154,160 Small increases in mast cell numbers have been
139
kemia appears to occur in male infants and is associated with t(X;6) observed at sites of pathology in rheumatoid arthritis, psoriatic arthri-
(p11.2;q23.3), resulting in the fusion of MYB and GATA1. 140,141 tis, scleroderma, and systemic lupus erythematosus. 154,160–162 Mast cells
Other types of AML that have an associated increase in basophils are reported to be increased in osteoporosis, but the extent to which
163
are more prevalent than acute basophilic leukemia. Such acute leuke- this increase reflects decreases in other cell types and/or a decrease in
mias most commonly have t(9;22), t(6;9), t(3;6), or 12p abnormali- bone matrix is unclear. Numbers of marrow mast cells can be increased
ties. 142–145 The t(9;22) AMLs have features similar to blast crisis of CML, in patients with chronic liver or renal diseases. Increases in mast cells
164
but studies show that de novo cases are associated with deletion of anti- also have been documented in infectious diseases, particularly at sites
gen receptor genes. The t(6;9) AML often is associated with erythroid
146
hyperplasia and dysplasia, a high frequency of FLT3 mutations, and
poor prognosis. 147–149
AML with inv(16) or t(16;16) are characteristically associated with
cells having large basophilic granules, but the cells containing these TABLE 63–4. Conditions Associated with Secondary
granules are generally thought to represent abnormal eosinophils rather Changes in Mast Cell Numbers
than basophils. 150
Although the clinical and pathologic features of acute basophilic I. Decreased Numbers
leukemia are largely similar to those of AML, affected patients occasion- A. Long-term treatment with glucocorticoids
ally exhibit symptoms that result from release of mediators (especially B. Primary or acquired immunodeficiency disorders (certain
histamine) from degranulating or dying basophils. 125,126,132,151 Remission mast cell populations; see text and reference 159)
induction therapy is similar to the therapy used for other types of AML, II. Increased Numbers
but management can be complicated by shock resulting from massive A. Immunoglobulin E–associated disorders
release of histamine and other mediators associated with acute cytolysis. 1. Allergic rhinitis
Chapter 88 provides further details on the acute leukemias associ-
ated with basophilia. 2. Asthma
3. Urticaria
DISORDERS AFFECTING MAST CELLS B. Connective tissue disorders
1. Rheumatoid arthritis
NORMAL MAST CELL LEVELS 2. Psoriatic arthritis
Mast cells cannot be identified in the blood of healthy individuals using 3. Scleroderma
standard techniques. However, mast cells can be observed in the blood 4. Systemic lupus erythematosus
of monkeys that have been treated chronically with large amounts of the C. Infectious diseases
22
KIT ligand SCF and in the blood of some patients with systemic mas- 1. Tuberculosis
152
tocytosis. Increases in tissue mast cells can occur by a combination 2. Syphilis
of enhanced progenitor influx and proliferation of resident mast cells
in tissues. 16,153 Human mast cells have been classified according to their 3. Parasitic diseases
content of neutral proteases as MC , because the granules contain trypt- D. Neoplastic disorders
T
ase but not detectable chymase, and MC , whose secretory granules 1. Lymphoproliferative diseases* (lymphoplasmacytic lym-
TC
29
contain both enzymes. The former mast cell type ordinarily predom- phoma/Waldenström macroglobulinemia, lymphoma,
inates in lung and gastrointestinal mucosal tissues, and the latter type chronic lymphocytic leukemia)
in dermis and submucosal tissues. 154–156 Mast cells that express chymase 2. Hematopoietic stem cell diseases* (acute or chronic
but little or no tryptase (MC ) also have been described. 157 myelogenous leukemias, myelodysplastic syndromes,
C
idiopathic refractory sideroblastic anemia)
SECONDARY CHANGES IN MAST CELL E. Lymph nodes draining areas of tumor growth
NUMBERS F. Osteoporosis*
G. Chronic liver disease*
Although long-term treatment with glucocorticoids (particularly topi- H. Chronic renal disease*
158
cal treatment of the skin) can result in diminished mast cell numbers,
no clinical disorder whose primary feature is a reduction in levels of * Can include increases in numbers of mast cells in the marrow.

Kaushansky_chapter 63_p0965-0982.indd 972 9/18/15 11:01 PM