Heme Onc Flashcards
platelet granules
- dense granules contain ADP and Ca
- alpha granules contain vWF, fibrinogen
monocytes
- differentiates into macrophages in the tissues
- large, kidney shaped nucleus
- extensive “frosted glass” cytplasm
macrophage
- differentiate from circulating blood monocytes
- activated by gamma-interferon
- CD 14 cell surface marker
eosinophils
- defends against helminths
- produces histaminidase and arylsulfatase (limits reaction following mast cell degranulation)
basophil
- mediates allergic reaction
- granules contain heparin, histamine and leukotrienes
mast cell
- IgE cross-links upon antigen binding, causing degranulation which releases histamine, heparin and eosinophil chemotactic factor
- involved in Type I HS reactions
- systemic mastocytosis: mast cell proliferation in the BM and other organs (increased gastric acid 2/2 histamine)
dendritic/Langerhans cells
- MHC Class II and Fc receptor on surface
- APCs
- Langerhans cells in the skin have “racket shaped” intracytoplasmic granules- Birbeck granules
platelet plug formation cascade
- injury causes subendothelial collagen to expose vWF
- adhesion of platelets to vWF via GpIb receptor
- platelet degranulation releases ADP and Ca, which causes platelets to expose GPIIb/IIIa receptors
- fibrinogen binds GpIIb/IIIa receptors –> platelet aggregation
increased ESR seen in
- infections, AI disease, malignant neoplasms, GI disease like UC, pregnancy
decreased ESR seen in
- polycythemia, sickle cell, CHF, microcytosis, hypofibrinogenemia
acanthocytes indicative of
- liver disease, abetalipoproteinemia
basophilic stippling indicative of
- anemia of chronic disease, Etoh abuse, Lead poisoning, Thalassemias
- Basically, ACiD alcohol is LeThal
schistocyte/helmet cells indicative of
- DIC, TTP/HUS, traumatic hemolysis (mechanical heart valve)
tear drop cell indicative of
- bone marrow infiltration (myelofibrosis)
target cell indicative of
- HbC disease, Asplenia, Liver disease, Thalassemia
- “HALT” said the hunter to his target
iron deficiency anemia labs
decrease iron, inc TIBC, low ferritin, inc RDW
- can have pitted nails
- increased free protoporphyrin because heme = iron + protoporphyrin and you are not making enough iron
Plummer-Vinson syndrome
- a manifestation of iron deficiency anemia
- triad: Fe def anemia, esophageal webs (dysphagia) and atrophic glossitis (beefy red tongue)
alpha thalassemia
- cis deletion in Asians, trans deletion in Africans
- 4 allele deletion - hydrops fetalis
- 3 allele deletion - HbH disease
- 2 allele deletion - no clinically significant anemia
beta thalassemia minor
- point mutations at splice sites and promoter sequences lead to decreasedB globin synthesis
- prevalent in mediterranean populations
- B chain is underproduced
- usually asymptomatic
- diagnose with increased HbA2 (< 3.5%) on electrophoresis
- carrier status carries protection from plasmodium falciparum malaria
beta thalassemia major
- homozygote mutation, B chain is absent –> severe anemia requiring blood transfusion
- marrow expansion leads to skeletal deformities (“chipmunk” facies)
- increased risk of parvo B19 aplastic anemia
- HbF is protective, so symptoms show up at 6 months
HbS/B thalassemia heterozygote
- mild to moderate sickle cell disease depending on the amount of B globin production
lead poisoning
- inhibits ferrochelatase and ALA dehydratase –> decreased heme synthesis and inc RBC protoporphyrin
- LLEEAADD: Lead Lines, Encephalopathy and Erythrocyte basophilic stippling, Abdominal colic and sideroblastic Anemia, Drops (foot and wrist drop) and Dimercaprol/EDTA for treatment
- give succimer to kids cause it “sucks” to be a kid with lead poisoning
sideroblastic anemia
- defect in protoporphyrin synthesis (heme = Fe + protoporphyrin, so defect in heme synthesis)
- can be hereditary defect in ALA synthase or aquired myelodysplastic syndromes or reversible (alcohol, lead, B6 def, copper def, isoniazid)
- Fe enters the mitochondria to form heme, but there is no protoporphyrin to combine with –> Fe laden macrophages around the nucleus
- increased iron, normal TIBC, inc ferritin
- treat with pyroxidine
Schilling Test
- enteric B12 + IM B12 - if increased in urine, diagnoses deficiency
- enteric B12 + IF - if increased in urine now, then its a IF deficiency
- if it never increases in the urine, its malabsorption (pancreatic insufficiency, ileal disease, or SIBO)
orotic aciduria
- cannot convert orotic acid to UMP (defect in UMP synthase)
- AR
- megaloblastic anemia non-responsive to folate or B12
- no hyperammonemia
- treat with uridne monophosphate to bypass mutated gene
intravascular hemolysis
- decreased haptoglobin, increased LDH, schistocytes and reticulocytes, urobilinogen in urine
extravascular hemolysis
- spherocytes, increased LDH + increased unconjugated bili
anemia of chronic disease
- inflammation causes the liver to release hepcidin, which binds ferritin and suppresses EPO
- low iron, low TIBC and high ferritin, increased free erythrocyte protoporphyrin
- treat the primary disease and some people get EPO (esp cancer pts)
G6PD
- most common enzymatic disorder of RBCs
- X linked recessive
- defect in G6PD leads to decreased glutathione, increased RBC susceptibility to oxidative stress and hemolysis
- back pain (Hgb is nephrotoxic), hemoglobinuria
- Heinz bodies and bite cells
pyruvate kinase deficiency
- AR defect in pyruvate kinase
- decreased ATP and rigid RBCs
- hemolytic anemia of the newborn
Hgb C defect
- glutamic acid to lysine mutation at residue 6 in B globin
- Hgb C crystals seen in smear
- will no travel as far on electrophoresis because there is decreased total negative charge
- Pts with HbCS have milder disease than Hb SS
PNH
- inreased complement mediated lysis of RBCs due to lack of GPI anchor for factors that prevent from complement destruction
- resp acidosis at night causes complement mediated RBC lysis –>coombs negative hemolytic anemia, pancytopenia, and venous thrombosis
- CD55/59 negative cells - acquired mutation in the precursor cell
- treat with eculizumab
- increased incidence of AML
Warm agglutinin hemolytic anemia
- IgG mediated, can be seen with SLE, CLL and certain drugs (penicillin, methyldopa)
- coombs +ve
cold agglutinin hemolytic anemia
- IgM mediated, acute anemia triggered by cold, seen in CLL, mycoplasma pneumonia, and infectious mono
- coombs +ve
lead poisoning
- enzymes affected, accumulated substrate and presenting symptoms
- ALA synthase and ferrochelatase
- protoporphyrin, d-ALA
- microcytic anemia, GI and kidney disease
acute intermittent porphyria
- enzyme affected, accumulated substrate and presenting symptoms
- porphobilinogen deaminase
- porphobilinogen, d-ALA, coporphobilinogen (urine)
- symptoms (5 P’s): painful abdomen, port-wind colored urine (gets darker when exposed to air), polyneuropathy, psychological disturbances, precipitated by drugs, alcohol and starvation
- treat with glucose and heme, which inihibit ALAS
porphyria cutanea tarda
- enzyme affected, accumulated substrate and presenting symptoms
- uroporphyrinogen decarboxylase
- uroporphyrin (tea colored urine)
- blistering cutaneous photosensitivity
- most common porphyria
Bernard-Soulier syndrome
- dec platelet count, increased bleeding time
- defect in platelet plug formation due to decreased Gp1b –> defect in platelet-vWF adhesion
Glanzmann thrombasthenia
- increased bleeding time
- defect in platelet plug formaiton due to decreased GpIIb/IIIa –> defective platelet aggregation
- blood smear shows no platelet clumping
immune thrombocytopenia
- dec platelet count, increased bleeding time
- anti-GpIIb/IIIa Abs –> splenic macrophage consumption of platelet/Ab complex
- may be triggered by viral illness, decreased platelet survival
- increased megakaryocytes on BMB
TTP
- inhibition or deficiency of ADAMTS 13 (vWF metalloproteinase) –> decreased degradation of vWF multimers
- large multimers increase platelet adhesion and increase platelet aggregation and thrombosis
- decreased platelet survival
- labs show schistocytes and increased LDH
- sympt (pentad): neurologic and renal symptoms, fever, thrombocytopenia, and microangiopathic hemolytic anemia
- treat with exchange transfusion and streroids
vWF disease
- increased bleeding time with normal or increased PTT
- vWF protects factor 8
- mild inherited bleeding disorder , AD
- diagnosed with ristocetin cofactor assay (decreased agglutination is diagnostic)
- treat with DDAVP
Factor V Leiden
- factor V resistant to inhibition by activated protein C, so adding protein C will not change the normal PTT
- most common cause of hypercoaguability in whites
prothrombin gene mutation
- mutation in the 3’ untranslated region –> increased production of prothrombin –> increased plasma levels and venous clots
antithrombin deficiency
- antithrombin deficiency - doesnt have any direct effect on PT/PTT, but PTT will not increase as much with heparin administration
protein C or S deficiency
- decreased ability to inactivate factors V and VIII
- increased risk of thrombotic skin necrosis with hemorrhage following coumadin
leukemoid reaction vs. CLL
- leukemoid reaction will have increased ALP
- CLL will have decreased ALP
Reed-Sternberg cells
- seen in Hodgkin lymphoma
- “owl eye” nuclei, CD15 and CD30+ (2 owl eyes x 15 = 30)
- nodular sclerosing type most common
- lymphocyte-rich forms have better prognosis
Burkitt Lymphoma
- occurs in adolescents and young adults
- t(8;14) - translocation of c-myc and heavy chain IgG
- starry sky appearance, sheets of lymphocytes with interspersed macrophages
- med sized lymphocytes with high proliferation ( high KI-67 fraction)
- associated with EBV
- jaw lesion in endemic form in Africa, pelvis and abdomen in sporadic form
diffuse large B cell lymphoma
- usually older adults, 20% kids
- t (14;18)
- most common type of non-Hodgkin lymphoma in adults
mantle cell lymphoma
- older males
- t (11;14) translocation of cyclin D1 and heavy chain IgG
- CD5+
follicular cell lymphoma
- adults
- t(14;18) traslocation of heavy-chain Ig and Bcl-2
- indolent course
- bcl2 inhibits apoptosis
- present with painless “waxing and waning” lymphadenopathy
adult T cell lymphoma
- occurs in adults
- caused by HTLV-1 (associated with IV drug abuse)
- adults present with cutaneous lesions, esp affects populations in Japan, West Africa, and the Carribean
- Lytic bone lesions, hypercalcemia
mycosis fungoides/Sezary syndrome
- common in adults
- adults present with cutaneous patches/plaques/tumors with potential to spread to lymph nodes and viscera
- circulating malignant cells seen in Sezary syndrome
- indolent, CD4+
ALL
- age < 15 years
- T cell ALL can present with mediastinal mass (dysphagia, dyspnea)
- associated with Downs “we ALL fall down”
- TdT +
- B cell form is CD10+
- most responsive to therapy
- may spread to the CNS and testes
- t( 12;21) has better prognosis
Small lymphocytic lymphoma/Chronic lymphocytic leukemia
- age > 60 years
- CD 20+, CD5+ B cell neoplasm
- often asymptomatic, progresses slowly, smudge cells in peripheral blood smear, autoimmune hemolytic anemia
- SLL is the same as CLL except CLL has increased peripheral blood lymphocytosis or BM involvement
hairy cell leukemia
- age: adults, mature B cell tumor of the elderly
- cells have filamentous, hair-like projections
- TRAP +ve
- causes marrow fibrosis (dry tap)
- treat wtih cladribine (2CDA), an adenosine analog (inhibits adenosine deaminase)
AML
- median onset 65 years
- Auer rods, peroxidase +, cytoplasmic inclusions seen in M3
- risk factors: prior exposure to alkylating chemo, radiation, myeloproliferative disorders, downs
- t(15;17) –> M3 responds to all-trans retinoic acid
- M3 due to PML/RARa fusion gene which prevents differentation
- can present with DIC if Aurer rods are released into plasma
CML
- peak incidence 45-85 years
- defined by philadelphia chromosome t(9;22)
- very low leukocyte alk phos
- responds to imatinib (tyrosine kinase inhibitor)
9;22 translocation
- philadelphia chromosome - CML
8;14 translocation
Burkitt lymphoma (c-myc activation)
11;14 translocation
mantle cell lymphoma (cyclin D1 activation)
14;18
follicular lymphoma (bcl2 activation)
15;17
M3 type AML
Langerhans cell histiocytosis
- lytic bone lesions and skin rash or recurrent OM with mastoid mass
- immature APCs
- express S-100 and CD1a
- have Birbeck “tennis racket” granules
Polycythemia Vera
- a chronic myeloproliferative disorder where hct > 55%
- somatic (non-hereditary) mutation of Jak2 gene – receptor associated tyrosine kinase
- often presents as intense itching after the shower
- rare but classic symptom is erythromelalgia (severe, burning pain and reddish or bluish discoloration) due to episodic blood clots in extremity vessels
essential thrombocytosis
- similar to polycythemia vera, but specific overproduction of abnormal platelets –> bleeding, thrombosis
- bone marrow contains enlarged megakaryocytes
myelofibrosis
- fibrotic obliteration of the BM
- teardrop RBCs and immature forms of the myeloid line