Path intro and WBC 1 Flashcards
how many units of blood do we have?
10 . . 1 unit=1 pint
How long do RBCs last?
Platelets?
Fresh frozen plasma?
42 days
5 days
1 year
what % of total blood is plasma?
cellular components?
55%
45%
When do Blood cell progenitors first appear? and where?
third week of emyryonic development in the yolk sack
Cells derived from the yolk sac are the source of what?
long lived tissue macrophages such as microglial cells in the brain and Kupffer cells in the liver
Where do definitive HSCs arise before they migrate to the liver during the third month
mesoderm of intraembryonic aorta/gonad/mesonephros region
What is the chief site of blood cell formation until shortly before birth?
liver
When do HSCs shift location and take residence in the bone marrow?
4th month
Until puberty, hematopoietically active marrow is found where?
it then becomes restricted to where?
throughout the skeleton
axial skeleton
a HSC loses it’s ability to self renew once it is past what stage?
multipotent progenitor
Processes that distort the marrow architecture, such as deposition of metastatic cancer or granulomatous disorders, can cause abnormal release of immature precursors into the peripheral blood, a finding referred to as what?
leukoerythroblastosis
What provides the best assessment of the morphology of hematopoietic cells?
Marrow aspirate smears
in normal adults, the ratio of fat cells to hematopoietic elements is about what?
- hypoplastic states? (aplastic anemia)
- hematopoietic tumors or in diseases characterized by compensatory hyperplasias (hemolytic anemias) and neoplastic proliferations such as leukemias?
- 1:1
- proportion of fat increased
- fat cells often disappear
What type of disorders often induce local marrow fibrosis?
How are the lesions best seen?
metastatic cancers and granulomatous diseases
-inaspirable so best seen in biopsies
Abnormally Low WBC count
leukopenia
reduction in number of neutrophils in blood
neutropenia
clinically significant reduction of neutrophils, making individuals susceptible to bacterial and fungal infections
Agranulocytosis
What is the most common cause of agranulocytosis?
drugs toxicity
Another name for a Natural Killer cell
Large granular lymphocyte
If we see extra medullary hematopoiesis after delivery, such as in the liver, what does this indicate?
a stressed infant
Where do we normally get Bone marrow from an Adult?
Pediatrics?
PSIS
sternum
What are the two cells that RESIDE in the peripheral blood?
where do leukocytes (monocytes, Granulocytes, and lymphocytes) reside?
Why are they seen in peripheral blood?
- Platelets and RBCs
- Tissue
- Peripheral blood is a transport medium
lifespan of circulating platelets if no significant clotting occurs
7-10 days
Senescent platelets are eliminated how?
phagocytosis in the spleen
Are nucleated red cells normal in peripheral blood?
No
At a Hb level about what, is EPO released at a constant rate?
About 10
As Hemoglobin levels fall below 10, plasma EPO does what?
increases LOGARITHMAICALLY in response to increasing severity of anemia
A peripheral blood “immature” RBC
reticulocyte
What % of red cell population should reticulocytes be
2%
describe a reticulocyte compared to a mature RBC
- contain remnant endoplasmic reticulum and ribosomes (rough ER) that forms a reticulum within the cytoplasm
- 20-30% larger than mature RBC
- circulate for 2-3 days before all remnants of ribosomal endoplasmic structures ae extruded
What may be used to possibly determine if we have an increase reticulocyte count?
what condition may possibly show this?
- RDW: red cell distribution Width
- Anemias where RBCs are being produced
once a monocyte exits the intravascular space, it differentiates into what?
macrophage
Meloblast lineage leads to what cells
granulocytes
What cells of the myeloblast lineage should not be seen in peripheral blood
- Myeloblast
- promyelocyte
- myelocyte
What does a myeloblast lack
granules
What is a juvenile granulocyte called?
what is a major feature?
Metamyelocyte
-indented nucleus
in what circumstances could you see metamyelocytes in the peripheral blood
left shift (acute pyogenic infections)
What Granulocytes can normally be seen In peripheral blood?
- metamyelocyte
- Band (horseshoe nucleus) - both of these in left shift
- segmented polymorphonuclear leukocytes: neutrophils: PMNs or polys
What do band forms not have?
filaments
describe a mature neutrophil
lobation: thin thread-like chromatin filaments join 2-5 lobes
life span of B lymphocytes?
T?
hours to days
days to years
most (around 80%) of circulating lymphocytes in the peripheral blood are what
T cells
% of plasma that is water
91%
relative measure of Red cell mass or the RBCs as a % of blood volume
hematocrit
plasma with diminished fibrinogen and other clotting factors
serum
Ulcerating necrotizing lesions of the gingiva, floor of the mouth, buccal mucosa, pharynx, or elsewhere in oral cavity are quite characteristic of what?
Describe the lesions
Agranulocytosis
-Deep, undermined, and covered by gray to green/black necrotic membranes
Severe neutropenia that occurs in association with monoclonal proliferations of large granular lymphocytes
LGL leukemia
With excessive destruction of neutrophils in the periphery, the marrow is usually what?
What else causes this feature?
hypercellular due to a compensatory increase in granulocytic precursors
-neutropenias caused by ineffective granulopoiesis (megaloblastic enemias and myelodysplastic syndromes)
Agranulocytosis caused by agents that suppress or destroy granulocytic precursors shows what in the marrow?
Hypocellularity
Serious infections from agranulocytosis are most likely when the neutrophil count falls below what level?
500 per mm^3
in some instances, such as following myelosuppressive chemotherapy, neutropenia is treated with what?
G-CSF
In acute infections, there is a rapid increase in the egress of mature granulocytes from the bone marrow pool, an alteration that may be mediated through the effects of what?
TNF and IL-1
What growth factor stimulates production of eosinophils?
Neutrophils?
IL-5
G-CSF
In sepsis, or severe inflammatory disorders (Kawasaki disease), leukocytosis is often accompanied by morphologic changes in the neutrophils such as what?
- Toxic granulations
- Dohle bodies
- Cytoplasmic vacuoles
patches of dilated endoplasmic reticulum that appear as sky blue cytoplasmic “puddles”
Dohle bodies
Acute lymphadenitis in the cervical region is most often due to drainage of microbes or microbial products from infections where?
Axillary or inguinal?
Mesenteric?
teeth or tonsils
extremities
acute appendicitis
Describe the nodes of acute lymphadenitis
enlarged and painful
Tingible body macrophages
follicular hyperplasia . . (chronic nonspecific lymphadenitis)
Causes of follicular hyperplasia?
- RA
- Toxoplasmosis
- early stages of infection with HIV
Features favoring a reactive nonneoplastic follicular hyperplasia
- Preservation of the lymph node architecture
- marked variation in the shape and size of the follicles
- The presence of frequent mitotic figures, phagocytic macrophages, and recognizable light and dark zones
What causes paracortical hyperplasia?
stimuli that trigger T cell mediated immune responses such as acute viral infections (infectious mononucleosis)
increase in the number and size of the cells that line lymphatic sinusoids
sinus histiocytosis (also called reticular hyperplasia)
Sinus histocytosis is particularly prominent in lymph nodes draining what
cancers such as carcinoma of the breast
Characteristically, lymph nodes in chronic reactions are what?
What locations?
nontender, as nodal enlargement occurs slowly over time and acute inflammation with associated tissue damage is absent
-inguinal and axillary nodes
reactive condition marked by cytopenias and signs and symptoms of systemic inflammation related to macrophage activation
Hemophagocytic Lymphohistiocytosis (HLH) -Also referred to as macrophage activation syndrome
The common feature of all forms of HLH is what?
systemic activation of macrophages and CD8+ cytotoxic T cells
- the activated macrophages phagocytose blood cell progenitors in the marrow and formed elements in the peripheral tissue
- Macrophages also release a cytokine stew or storm . . shock like picture
What are familial forms of HLH associated with?
NK to properly form of deploy cytotoxic granules
What is the most common trigger of HLH
infection, particularly EBV
clinical features of HLH
-present with an acute febrile illness associated with splenomegaly and hepatomegaly
What is usually seen on bone marrow exam with HLH
hemophagocytosis
What do Lab studies reveal in HLH?
- anemia, thrombocytopenia, and very high levels of plasma ferritin and soluble IL-2 receptor (inflammation)
- elevated liver function tests and triglyceride levels (hepatitis)
coagulation studies of HLH
- evidence of DIC
- if untreated can progress rapidly to multiorgan failure, shock, and death
prognosis of HLH without treatment?
Grim . .less than 2 months
with prompt treatment of HLH about half patients survive but with what sequelae
- renal damage in adults
- growth and mental retardation in children
What are the 3 types of myeloid neoplasia and describe them?
- Acute myeloid leukemia (AML): immature progenitor cells accumulate in the bone marrow
- Myelodysplastic syndromes: associated with ineffective hematopoiesis and resultant peripheral blood cytopenias
- Chronic myeloproliferative disorders: increased production of one or more terminally differentiated myeloid elements usually leads to elevated peripheral blood counts
Dendritic cell proliferations . . .Langerhans cells
Histiocytoses
what protoocogene is activated in germinal center B cell lymphomas by TRANSLOCATIONS to the transcriptionally active Ig locus
MYC
What proto-oncogenes has a role in many B cell malignancies and is activated by POINT MUTATIONS
BCL6
What inherited genetic diseases are at increased risk for acute leukemia?
childhood leukemia?
- Bloom syndrome, Fanconi anemia, and ataxia Telangiectasia
- Down syndrome and Type I neurofibromatosis
Virus and Malignancy: HTLV-1?
- EBV
- KSHV
- T-cell leukemia/lymphoma
- Burkitt lymphoma, 30-40% of HL, and many B cell lymphomas in the setting of T cell immunodeficiency
- Malignancy effusion often in pleural cavity
Chronic inflammation and malignancy: H. pylori?
HIV?
- Gastric B-cell lymphomas and intestinal T cell lymphomas
- B-cell lymphomas within any organ. systemic hyperplasia of GERMINAL CENTER
Smoking increases risk of what malignancy
Acute myeloid leukemia in adults
Blasts in peripheral blood?
ALWAYS abnorma