Hematology Flashcards
Erythropoietin
synthesized in peritubular capillaries
Reticulocyte count
measure of effective erythropoiesis; correct for degree of anemia
Extramedullary hematopoiesis
Hematopoiessi outside bone marrow (e.g. spleen)
Newborn physiologic anemia
drop in Hb due to replacement of HbF RBCs with HbA
Pregnancy
Hb and Hct decreased
greater increase in plasma volume than RBC mass
Anemia
normal oxygen saturation and arterial PO2
MCV
average VOLUME of RBCs; useful for anemia classification
MCHC
average Hb concentration in RBCs
When is MCHC decreased? When is MCHC increased?
MCHC
- decreased in microcytic anemias
- increased in spherocytosis
Thalassemias
- decreased in MCV
- increased in RBC count
RDW
RBC size variation
- increased in iron deficiency
- decreased in anemia of chronic disease, sideroblastic anemia
Mature RBC
anaerobic glycolysis; no mitochondria or HLA antigens
Total iron binding capacity is increased
- in iron deficiency
Total binding capacity is DECREASED
in anemia of chronic disease OR sideroblastic anemia
% Saturation
- decreased in iron deficiency or anemia of chronic disease
% Saturation is increased
sideroblastic anemia
Serum ferritin is decreased
- iron deficiency
Serum ferritin is INCREASED
anemia of chronic disease, sideroblastic anemia, normal thalassemia
Microcytic anemia
- seen in iron deficiency (most common cause)
- anemic chronic disease
- thalassemia
- sideroblastic anemia
Most common cause of iron defieicny in a child
Meckel’s diverticulum
Iron deficiency in women < 50
Menorrhagia (heavy bleeding during menses)
Iron deficiency man < 50
Most common cause is peptic ulcer disease
Iron deficiency in men/women > 50
Colon cancer
Stages of iron deficiency
- decreased ferritin, Fe, and % saturation
- increased TIBC, normocytic then microcytic anemia
Anemia of chronic disease
Most common anemia in malignancy and alcoholics
Alpha Thalassemia trait
Autosomal recessive
two alpha globin gene deletions
- normal Hb electrophoresis
HbH disease
- three alpha-globin gene deletions;
- hemolytic anemia
- four Beta-globin genes
Hb Bart’s disease
four alpha globin gene deetions
four gamma globin genes
B- thalassemia minor
Autosomal Recessive
- DNA splicing defect
- increased HbA2 and F
- idecreased HbA
B-thalassemia major
nonsense mutation with stop codon
- hemolytic anemia
- very elevated HbF
- increased HbA2
Sideroblastic anemia
- defect in mitochondrial heme synthesis producing ringed sideroblasts
Causes of sideroblastic anemia
- Alcohol
- Pyroxidine deficiency (may be due to isoniazid tx of TB)
- Lead poisoning
Lead poisoning
- Inhibits ferrochetolase
- ALA Dehydrase (can’t convert ALA to porphobillogen??)
- Ribonuclease
Sx of lead poisoning in children
- Growth retardation
- Pb in epiphyses
- Abdominal colic
- Encephalopathy
Sx of lead poisoning in adult
Peripheral neuropathy
Proximal renal tubule damage (Fanconi’s syndrome)
Lab of Pb poisoning
- Course basophillic stippling RBCs
- decreased MCV
- increase in Pb levels
- increase in ALA
Vitamin B12 sources
Animal products (requires intrinsic factor reabsorption in terminal ileum)
Vitamin B12
transfers methyl group to homocysteine
- involved in proprionate metabolism
- end product of succinyl CoA
R factor
binds with B12 in mouth, removed by pancreatic enymes in small intestine
Pernicious anemia
autoimmune destruction of parietal cells
sx: chronic gastritis in body/fundus, acholrydia
- increase in gastrin
Causes of folate deficiency
- Alcohol (most common cause)
- Poor diet
- Drugs
- Malabsorption
- Pregnancy
- Goat milk
Drugs and Folate deficiency
- Alcohol
- Oral contraceptives
- Phenytoin
- Methrotrexate
- Trimethroprim
- 5-fluorouracil
Intestinal conjugase in folate metabolism
Inhibited by phenytoin
Jejunal uptake of monoglutamate of folate
Inhibited by alcohol and oral contraceptives
Dihydrofolate reductase
inhibited by methotrexate, trimethoprim
Thimydilate synthase
inhibited by 5-fluorouracil
Most common cause of increased serum homocysteine
Folate deficiency
Lab in B12/folate deficiency
- Pancytopenia
- Hypersegmented neutrophils
- Increased in homocysteine
Lab finds unique to B12 deficiency
- increased gastrin (pernicious anemia)
- increased methylmalonic acid
Likely diagnosis: B12 reabsorbed after administration of intrinsic factor.
Pernicious anemia
Likely diagnosis: B12 reabsorbed after administration of antiobiotics
Bacterial overgrowth
Likely diagnosis?
B12 reabsorbed after administration of pancreatic enzyme
Chronic pancreatitis
Hb and Hct after acute blood loss
- Initially normal Hb and Hct
.9% saline uncovers RBC deficit
Aplastic anemia
- Drugs (e.g. phenylbutazone)
- Infection (e.g. parvovirus)
- Benzene
Lab findings for aplastic anemia
- Pancytopenia
- ## Hypocellular bone marrow
Anemia in renal disease
Normocytic
- decreased EPO
Extravascular hemolysis
- Macrophage phagocytosis of RBCs
- Increase in unconjugated bilirubin and urine UBG
Intravascular hemolysis
- Decrease in serum haptoglobin
- Hemoglobinuria
- Hemosideriuria
Congenital spherocytosis
- Autosomal dominant
- defectin spectrin
- Extravascular hemolysis
- Splenomegaly
Blood findings in spherocytosis
Normocytic anemia
- Dense RBCs
- Increase in MCHC
- INcrease in osmotic fragility
Blood findings in spherocytosis
Normocytic anemia
dense RBCs
Increase in MCHC
Increase in osmotic fragility
PNH
missing decay acceerating factor
- complement destruction RBCs
- neutrophils
- platelets
Sx of PNH
- Pancytopenia
- Hemoglobiuria
- Positive sugar water test and acidified serum test
HbSS
- Autosomal Recessive
- Missense mutation (valine for glutamic acid; 6th positive B-globin chain)
Causes of sickling
- Increase in deoxyhemoglobin (hypoxemia and acidosis)
- HbS > 60%
HbF
inhibits sickling
hydroxyurea increases HbF
Pathophysiology of HbSS
Vasoclusive crisises Hemolytic anemia ( Extravascular)
HbSS in children
Dactylitis (6 - 9 months)
Streptococcus pneumoniae sepsis (dysfunctional spleen)
HbSS osteomyelitis caused by what microorganism?
Salmonella paratyphi
HbSS complications
Aplastic crisis (parvovirus) Acute chest syndrome Autosplenectomy Calciym bilirubinate gallstones Priapism Asceptic necrosis
HbAS
- microhematuria from sickling in renal medulla
- renal papillary necrosis
Hb electrophoresis
HbAS - HbA (55 - 60%)
HbS (40 - 45%)
HbSS - HbS 90- 95%
HbF - 5-10%
Blood findings in HbSS
Sickle cells
Target cells
Howell-Jolly bodies (nuclear remnants)
G6PD deficiency
X-linked recessive Oxidant damage (due to peroxide) to Hb (e.g. primaquine, dapsone, fava beans)
Blood findings G6PD deficiency
Heinz bodies (denatured Hb; special stain) Bite cells
Pyruvate kinase deficiency
- Decreased ATP
- RBCs dehydrated
- increase in 2,3 BPG (right shift of oxygen-blood curve)
Warm Autoimmune-hemolytic anemia
IgG Extravascular hemolysis (e.g. SLE, drugs)
Cold auto-immune hemolytic anemia
IgM Intravascular hemolysis (e.g. CLL, mycoplasma)
Pencillin HS rxn
IgG antibody against penicilin attached to RBC (type II hypersenstivity)
Methyldopa
drug alters Rh antigens;
IgG antibody against Rh antigens (type II antibody)
Quinidine
drug IgM immune complexes
intravascular hemolysis
type III hypersensitivity
Lab findings for autoimmune hemolytic anemia
Positive direct Coombs
spherocytes
Microangiopathic hemolysis
Mechanical damage causing intravascular hemolysis
Causes of macro/micro hemolysis
Aortic stenosis (most common cause0
DIC
TTP
HUS
Peripheral blood findings micro/macro hemolysis
Schistocytes
Iron deficiency from hemoglobinuria
Malaria
Intravascular hemolysis correlates with fever
Falciparum - ring forms and gametocytes
Leukemoid reaction
exaggerated WBC response to infection
Usually due to infection
Leukoerythroblastic reaction
Marrow infiltrative disease peripheralizes myeloblasts/nucleated RBCs
Leukemoid reaction
exaggerated WBC response to infection; usually due to infection
Causes of leukoerythroblastic reaction
Bone metastais MCC
myelofibrosis
Eosinophilia
Type I hypersensitivity (e.g. penicillin reaction)
Invasive helminthic infection
Helminths not producing eosinophili
Pinworms
Adult worms in ascariasis
Atypical lymphocytes
Mononucleosis CMV Toxoplasmosis Viral hepatitis Phenytoin
Mononucleosis
due to EBV
EBV attaches to CD21 receptors in B cells
Clinical findings for mononucleosis
Exudative tonsillitis
Generalized lymphadenopathy
Hepatosplenomegaly
Lab findings for mononucleosis
Atypical lymphocytosis
IgM heterophile antibodies against horse RBCs (MONOSPOT)
Lymphopenia
T-cell deficiences (HIV)
combined B/T deficiency (adenine deficiency)
Lymphocytosis
Viral infections; whooping cough
Chronic myeloproliferative disease
Neoplastic stem cell disorder
Splenomegaly
Marrow fibrosis
Risk of leukemia
Examples of myeloproliferative disease
Polycythemia vera
Myelofibrosis
Myeloid metaplasia
Relative polycythemia
Decrease in plasma volume, increase in RBC count, normal RBC mass
Absolute polycythemia
Increase RBC count and RBC mass
Appropriate polycythemia
Hypoxic stimulus for EPO to generate RBCs
Causes of appropriate absolute polycythemia
Lung disease
Cyanotic heart disease
High altitude
Appropriate absolute polycythemia
Normal plasma volume
Increase in RBC mass
Decrease SaO2
Increase EPO
Inappropriate absolute polycythemia
No hypoxic stimulus for EPO
Causes of inappropriate polycythemia
Ectopic secretion EPO
Polycythemia vera
Polycythemia vera
Increase plasma volume and RBC mass
normal SaO2
Decreased EPO
Ectopic EPO (renal cell carcinoma)
Normal plasma volume
Increase in RBC mass
Normal SaO2
Increase in EPO
Myelofibrosis myeloid metaplasia
Marrow fibrosis
Extramedullar hematopoiesis
Splenomegaly
Lab findings in myelofibrosis
Tear drop RBCs
Dry bone marrow aspirate (marrow fibrosis)
Essential thrombocythemia
MPD with increase in abnormal appearing platelets
Myelodysplastic syndrome
severe anemia in elderly; 30% develop leukemia
ringed sideroblasts
Benzene
associated w/ aplastic anemia
acute leukemia
Leukemia by age
ALL: newborn
AML: 15- 60
CML: 40 - 60
CLL: > 60
Acute vs chronic leukemia
Acute: blasts > 30% in bone marrow
Chronic: blasts < 10% in bone marrow
Acute Myeloproliferative Leukemia
Auer rods in myeloblasts
Acute Promyelocytic leukemia
t(15; 17)
defect in retinoic acid
Rx: retinoic acid (increased maturation)
DIC
Acute monocytic leukemia (AML)
Gum infiltration
Chronic Myelogenous Leukemia
t(9; 22) of ABL proto-oncogene
Philadephia chromosome 22
Decrease leukocyte alkaline phosphatase score
ALL
early pre-B (80%)
CALLA (CD10)
TdT positive
CNS testicle involvement
Indicators of good prognosis of ALL
t(12; 21)`
Chronic Lymphoblatic Leukemia (CLL)
pts > 60 years
B cell neoplasm
- decrease in gamma-globulins
- Generalized lymphadenopathy
Adult T-cell Leukemia
HTLV-1
CD4 T-cells
skin infiltration
lytic bone lesions with hypercalcemia
Hairy cell leukemia
positive TRAP stain (“trap the hairy spider”)
splenomegaly
Rx with purine nucleosides
Nodal sites
germinal follicles B cells paracortex T cells sinuses histiocytes
Testicular cancer metastasis
to para-aortic lymph nodes
Stomach cancer metastasis
to supraclavicular lymph nodes
Phenytoin side effect
- ginigival hyperplasia
- atypical lymphocytosis
- nystagmus
- ataxia
Cat scratch disease
Bartonella henselaw
granulomatous microabscesses
Follicular B-cell lymphoma
t(14, 18)
overexpression of BCL-2 (anti-apoptosis gene)
Burkitt lymphoma
t(8, 14) overexpression of c-myc EBV association common childhood Non-Hodgkin's Lymphoma "starry sky appearance
Extranodal lymphomas
risk factors:
H-pylori (stomach)
Sjorgen’s syndrome
Mycosis fungiodes
CD4 T neoplasm
skin lesions with Pautrier’s microabcesses
- when spread to blood becomes Sezary syndrome
Sezary syndrome
leukemic phase of Mycosis fungiodes
Polyclonal gammopathy
sign of chronic inflammation
Monoclonal gammopathy
M component (spike) sign of plasma cell disorder
Bence Jones proteins
light chains in urine
- predicive of a malignant plasma cell disorder (e.g multiple myeloma)
Multiple myeloma
patients > 45
- M spike
- lytic bone lesions
- pathological fractures
- hypercalcemia
- renal failure
MGUS
monoclonal gammopathy, may progress to myeloma
Findings in MGUS
elderly patient
no Bence Jones proteins
no malignant plasma cells
Waldenstrom’s macroglobulinemia
lymphoplasmacytic lymphoma
IgM M spike (vs. IgG and IgA in multiple myeloma)
Hyperviscosity (b/c IgM are large molecules)
Hodgkin’s lymphoma
neoplastic compnent Reed Stenberg cell (“owl eyes”)
CD15 + and CD30+
- bimodal distribution: young adulthood or > 55 years
- EBV association
- Constitutional symptoms (e.g. weight loss, night sweats)
Reed Steinberg cell
- seen in Hodgkin’s lymphoma
- binucleate or bilobed halves as mirror images
- more RS cells present the worse the prognosis
Non-sclerosing Hodgkins
- female dominant
- supraclavicular nodes + anterior mediastinal nodes
Mixed cellularity Hodgkins
male dominant
numerous RS cells
EBV association