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Flashcards in Immuno 4 Deck (18)
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1

Lymphopenia (lymphocytopenia)-nonprolif WBC disorder

Not very common
Often secondary to disease or therapy/drugs
Reduced lymphocytes in blood (

2

Leukopenia (leukocytopenia)-nonprolif WBC disorder

Reduced granulocytes
Neutropenia as reduced neutrophils (

3

Leukocytosis-Reactive proliferative WBC disorder

Classified according to cellular subtype
 Neutrophilic leukocytosis:
As a result of bacterial infection or sterile inflammation (burns, myocardial infarction)
Eosinophilic leukocytosis (eosinophilia):
As a result of allergic reactions, parasitic infections
Basophilic leukocytosis (basophilia)
not common, usually associated with other conditions such as neoplastic disease
Lymphocytosis:
often associated with chronic infections

4

Leukocytosis in Infectious mononucleosis

Caused by EBV infection
Characterized by fever, sore throat, lymphadenitis & lymphocytosis of CD8+ T cells
Monospot test is diagnostic

5

Lymphadenitis

Reactive proliferative WBC disorder
Lymphadenitis (inflammation of lymph node) is usually associated with lymphadenopathy (enlargement/swelling)
Cat scratch lymphadenitis by Bartonella henselae

6

Acute lymphadenitis is characterized by

enlarged B cell germinal centers

7

Chronic lymphadenitis occurs as:

Follicular hyperplasia: Activated B cells migrate into follicular zone
Paracortical (mantle) hyperplasia: Activation of interfollicular T cells that proliferate and displace B cell germinal centers
Sinus histiocytosis (draining sinuses): Distention of lymphatic sinusoids due to endothelial hypertrophy and infiltration of macrophages (histiocytes)

8

Neoplastic WBC Disease

Malignant leukocytes arise form either myeloid (RBC/granulocyte series) or lymphoid (T/B) cells representing arrested development
Cancers arising from early progenitor cells will be ‘blastic’ cancers (acute lymphoblastic leukemia)
WBC cancers arising in the bone marrow/thymus are leukemias
WBC cancers arising from germinal lymphoid tissues are lymphomas
‘acute’ vs ‘chronic’

9

Acute Lymphoblastic Leukemia/Lymphoma (ALL)

ALLs constitute 80% of childhood leukemias
B-cell origin in children by 4 years, while T-cell origin late teens
Clinically manifests as abrupt onset with anemic fatigue, fever from infections, bleeding, bone pain
Generalized lymphadenopathy, splenomegaly & hepatomegaly as well as CNS symptoms (vomiting, headaches) are more common in ALL than CML

10

B-ALLs can have

the 9:22 translocation of Philadelphia chromosomes as in CML, usually non-random karyotypic abnormalities

11

Acute myeloid leukemia (AML)

Myeloproliferative disorders result from acquired genetic abnormalities in myeloid cell progenitors that lead to excessive proliferation and diminished function
-AML neoplastic block of myeloid blast cell differentiation
-Auer rods

12

Chronic myeloid leukemia (CML) & Philadelphia chromosome

CML is a chronic myeloproliferative disorder with large numbers of mature, but functionally abnormal myeloid (granulocyte) cells
 -Associated with Philadelphia chromosome, a translocation between the bcr gene & abl proto-oncogene: t(9;21)
Generally affects adults (25-60 years) with initial onset of disease with nonspecific symptoms

13

Hodgkin’s Lymphoma

Classical Hodgkin's disease demonstrates a moderate number of Hodgkin's cells with identifiable Reed-Sternberg cells
Reed-Sternberg cells have a characteristic morphologic appearance with a bilobed (mirror image), nucleus prominent eosinophilic nucleoli and a moderate-to-abundant amount of cytoplasm
Large cells measuring 15-45 um
typically express CD30, CD15

14

Hodgkin’s (vs non)

Usually localized to single group of nodes
Orderly, contiguous (direct) spread
Mesenteric nodes and Waldeyer ring (tonsillar/nasal-associated lymphoid tissue) rarely involved
Extranodal involvement uncommon

15

nonHodgkin’s

Frequent involvement of peripheral nodes
Noncontiguous spread
Mesenteric nodes and Waldeyer ring involvement
Extranodal involvement common

16

Hodgkin’s: Nodular sclerosis

Most common form of Hodgkin’s
Typically involves cervical, supraclavicular & mediastinal lymph nodes
‘Lacunar’ type RS cells that is multilobulated

17

Hodgkin’s: Mixed cellularity

Most common form of Hodgkin’s in pts >50 years with male predominance
Disseminates more than nodular sclerosis type
Lacks dense bands of collagen seen in NS, but abundant eosinophils & Hodgkin's cells

18

Hodgkin’s: Lymphocyte-predominace

RS cells have multilobed, puffy nucleus
B cells express fail to express CD15 & CD 30 unlike other RS cells