Clin Med Diseases (RBC/platelets) Flashcards
Thrombocytopenia is…
low platelets
What might cause thrombocytopenia?
- impaired bone marrow production
- increased destruction of platelets
- splenic sequestration
MC cause: bleeding
3 types of thrombocytopenia
idiopathic
thrombolic
von willebrand
What is the pathophysiology of idiopathic thrombocytopenia purpura?
the immune system destroys platelets
When does idiopathic thrombocytopenia purpura most often occur (etiology)?
immune response:
after infection, with HIV, with SLE
Who would most likely get idiopathic thrombocytopenia purpura (ITP)?
Acute: self-limited, autoimmune IgG, children (viral)
Chronic: coexisting with other autoimmune, any age
What is the clinical presentation of idiopathic thrombocytopenia purpura (ITP)?
mostly asymptomatic
may have sudden onset of bruises, petechiae, mucosal bleeding
How would you diagnose idiopathic thrombocytopenia purpura (ITP)?
What will your lab values be?
Acute: CBC shows decreased platelets (10K-20K), eosinophilia, mild lymphocytosis
Chronic: platelet count 25K - 75K
Peripheral smear shows megakaryocytes
How do you treat idiopathic thrombocytopenia purpura (ITP)?
Acute: self-limiting, sometimes corticosteroids, IVIg, splenectomy
Chronic: REFER.
What is the pathophysiology of thrombolic thrombocytopenia purpura (TTP?)
platelets aggregate in microcirculation, resulting in a clot, then a bleed
How is thrombolic thrombocytopenia purpura (TTP) classified?
Microangio-pathic hemolytic anemia
Who gets thrombolic thrombocytopenia purpura (TTP?) What is the epidemiology?
RARE but fatal. Found in previously healthy people.
20-50 years of age, female, pregnant, estrogen use, HIV/AIDS, certain medications
How does TTP present clinically?
purpura (big bruise), petechiae, bruising
neurologic abnormalities
How do you diagnose TTP? What will lab values be?
CBC: anemia, schistocytes, î LDH, î indirect bilirubin, î D-dimer
Ab against ADAMTS 13
How do you treat TTP?
Refer!!!
emergency plasma transfusion
What is the pathophysiology of von Willebrand disease (vWd)?
von Willebrand protein helps adhere platelets to vessels, helps stabilize factor VIII;
in vWd, the body is deficient in vW protein;
therefore, vWd affects platelet aggregation and prolongs bleeding time
The most common hereditary coagulation disorder
How do you classify vWd? (3 types)
type 1: most common with mild bleeding
type 2: more severe than 1
type 3: rare, most severe
Who gets vWd and how?
autosomal dominant, congenital
both men and women
What is the clinical presentation of vWd?
bleeding in nasal, sinus, vaginal, and GI mucus membranes
menorrhagia
bleeding exacerbated by NSAIDs, aspirin
bleeding relieved by estrogen, pregnancy
How do you diagnose vWd? Lab values?
PT normal, but PTT mildly prolonged
PFA prolonged
vWF low
How do you treat vWd?
Desmopressin (DDAVP) - to stim. endothelial release of vWF
Factor VIII concentrates to replace Factor VIII
Hemophilia A pathophys
deficient in Factor VIII
therefore, impaired coagulation pathway/can’t make platelets
leads to excess bleeding
Most severe bleeding d/o
How do people get Hemophilia A? Who gets it?
X-linked recessive
only in males
2nd most common congenital coagulopathy
What are the symptoms of Hemophilia A?
excessive bruising
repeated bleeding episodes with hemarthrosis, epistaxis, intracranial bleeds
blood in vomit, stool, urine, soft tissue, and gingiva
excessive bleeding after surgery/trauma/compartment syndrome
How do you diagnose Hemophilia A?
PTT prolonged
PT, PFA, fibrinogen level, platelets NORMAL
dec. Factor VIII, C levels
vWF is normal
What is the tx for hemophilia A?
infuse pt with recombinant Factor VIII concentrate*
Desmopressin (DDAVP) to elevate Factor VIII
What should patients with Hemophilia A avoid?
aspirin!
What is the pathophys of Hemophilia B?
(AKA Christmas disease)
deficiency of Factor IX
therefore, also excess bleeding
Who gets Hemophilia B and how?
X-linked recessive dz
Males
less common than A
What is the clinical presentation of Hemophilia B?
Similar to A!
excessive bleeding, bruising, hematomas, hemarthrosis, compartment syndrome
How do you diagnose Hemophilia B?
low Factor IX
prolonged PT
normal platelet count
How do you tx Hemophilia B?
Literally do the same thing as Hemophilia A, except use Factor IX.
What is the pathophys of Disseminated intravascular coagulation (DIC)
there is activation of intravascular coagulation
there is also increased fibrinolysis
therefore, you get both excess clotting AND bleeding
What causes DIC?
clotting cascade triggered by:
surgery, trauma
sepsis, vascular disorders
pregnancy, malignancy
burns, shock
What are the clinical symptoms of DIC?
may present as petichiae, purpura, oozing, or severe postpartum bleeding
diffuse bleeding
microvascular thrombosis
bleeding in basically every important organ system
shock
(can lead to organ failure)
What will lab values show you for DIC?
(there is not a huge focus on this anywhere)
prolonged PT
prolonged PTT
abnormal PFA/low platelets
decreased fibrinogen
increased fibrin degradation
How do you treat DIC?
treat the cause.
can give frozen plasma, platelets, or fibrinogen
can give heparin to dec coagulation
What is the outcome of people with DIC?
most die
In patients with clots, will they have high or low D-dimer?
high
What is the most common acquired coagulopathy?
Vit K deficiency
What causes Vit K deficiency?
poor diet, liver failure, malabsorption, malnutrition, some drugs (broad spectrum abx)
What are the clinical features of Vit K deficiency?
typically post-op
not eating well, receiving broad spectrum abx
maybe soft tissue bleeding
Lab findings for Vit K deficiency?
PT prolonged
PTT prolonged
Fibrinogen, platelets normal
Levels of Vit K and clotting factors decreased
Tx of Vit K deficiency
treat underlying cause.
Give Vit K
treat hemorrhage with frozen plasma
Eat a diet high in leafy veggies
What causes iron deficiency anemia?
Most common
menstruation, pregnancy, bleeding
What causes folate deficiency anemia?
most likely poor dietary intake (vegan diet)
What causes B12 and pernicious anemia?
B12 defiency in diet (vegans)
Could lack intrinsic factor (“pernicious disorder”), have ileum disorder
Some drugs (H2 antagonists)
What causes aplastic anemia?
This is a disorder of pluripotent bone marrow stem cells
Reduction of RBC, WBC, and platelets
Unknown cause
What causes hemolytic (G6PD) anemia?
X-linked
RBCs break down prematurely, most common enzyme deficiency (G6PD)
What causes sickle cell anemia?
abnormal Hgb
autosomal recessive
What do the cells look like in iron anemia?
hypochromic
microcytic
What do cells look like in folate anemia?
macrocytic
megaloblastic
What do the cells look like in pernicious anemia?
macrocytic/megalobastic
What do the cells look like in aplastic anemia?
hypoproliferative
What do the cells look like in hemolytic anemia?
normocytic
What do the cells look like in sickle cell anemia?
sideroblastic
sickled under stress
What are the risks for iron anemia?
pre-menopause
pregnancy
frequent blood donor
diet (milk, Vit C, Zn), family history
What are the risks for folate anemia?
alcohol
pregnancy
some medications (methotrexate)
What are the risks for B12 anemia? (pernicious)
being vegan
gastric surgery, pancreatic insufficiency, Chron’s disease
What are the risks for aplastic anemia?
exposure to toxins via certain meds
Some blood/autoimmune dz
Thymus tumors
What are the risks for G6PD deficiency anemia?
being AA or Greek
Male
stress (inc hemolysis)
sulfa drugs, fava beans, nitrofurantoin
What are the risks for sickle cell anemia?
being AA (autosomal recessive)
(many things can trigger a sickle cell crisis)
What is the clinical presentation of someone with iron anemia?
weakness/fatigue, tachy, exertional dyspnea, pallor
pica, cheilosis, glossitis
may have koilonychia (spoon-shaped nails)
What is the clinical presentation of someone with folate anemia?
tachy, pallor, exertional dyspnea, fatigue
sore tongue (glossitis)
GI symptoms
What is the clinical presentation of someone with pernicious anemia?
tachy, pallor, exertional dyspnea, fatigue
GI symptoms/malabsorption
glossitis
neurological symptoms
What is the clinical presentation of someone with aplastic anemia?
tachy, pallor, exertional dyspnea, fatigue
insidious onset, palpitations, progressive weakness, weight loss
heavy bleeding, systolic ejection murmur, petechiae
fever
Congenital: short, microcephaly, abnormal thumbs, oral leukoplakia
What’s the clinical presentation of someone with G6PD anemia?
tachy, pallor, exertional dyspnea, fatigue
females usually have NO symptoms
jaundice, dark urine
What’s the clinical presentation of someone with sickle cell anemia?
severe, recurrent abd pain
acute chest syndrome
splenomegaly, jaundice, fever
pain everywhere
swollen hands and feet (dactylitis)
NO erythema
AVN, bone infarctions, vascular occlusions
Diagnostics for iron anemia?
MCV low (microcytic)
reticulocytes low (bone marrow problem)
Fe, ferritin low
TIBC high
periph smear: anisocytosis, poikilocytosis
Dx for folate anemia?
folate low
MCV high
low reticulocyte
LDH high
smear: macro-ocalocytes & hypersegmented polymorphonuclear cells
Dx for B12 anemia?
B12 low
MCV high
low reticulocyte
Intrinsic factor Ab
Dx for aplastic anemia?
All blood cells low
reticulocytes low
Fe high
TIBC normal
Get FULL workup (CBC, liver fn, UA,
Dx for g6pd anemia?
periph smear: Heinz bodies, bite cells
G6PD low
reticulocytes high
bilirubin high
Dx for sickle cell anemia?
Screen: Sickledex test
Electrophoresis (Hgb S is >50%)
peripheral smear for sickled cells, target cells, nucleated RBCs, Howell-Jolly bodies
reticulocyte high
LDH high
bilirubin high
ferratin high
WBC high
Tx for iron anemia?
Ferrous sulfate
Find source of bleeding
Tx for folate anemia?
Folic acid supplement
Avoid alcohol
Tx for pernicious anemia?
Vit B12 supplement (IM)
Tx for aplastic anemia?
Stem cell replacement (bone marrow/periph blood transplant)
Tx for G6PD anemia?
mostly self-limiting
avoid stress
avoid certain medicines and oxidative drugs
Tx for sickle cell anemia?
Oxygen, IV fluids, transfusions
Children should get LD penicillin daily from birth to 6 years, pneumovax, as well as lots of other screening
What is the pathophys of chronic anemia?
Chronic infections/inflammation causes increased hepcidin levels, which blocks iron absorption in the gut and blocks iron release from bone marrow
What causes chronic anemia?
chronic anemia is a sx rather than a disease
autoimmune diseases: SLE, RA
sickness: cancer, hospitalization
What do cells look like in chronic anemia?
microcytic or normocytic
normochromic
hypoproliferative
What are the symptoms of chronic anemia?
tachy, pallor, exertional dyspnea, fatigue
chronic inflammation
How do you diagnose chronic anemia?
Elevated CRP and ESR
Normal-high ferritin level
Treatment of chronic anemia?
Treat underlying cause
Transfusion if symptomatic
What will chronic anemic patients not respond to for treatment?
epo or iron supplements
What is the pathophysiology of alpha-thalassemia?
deficient synthesis of alpha Hgb chain (low Hgb A)
usually leads to RBC hemolysis & increased iron
What is the pathophysiology of beta-thalassemia?
deficient synthesis of beta-Hgb (low Hb A2 and low Hb F)
usually leads to RBC hemolysis & increased iron
What do cells look like in alpha and beta thalassemia?
microcytic
hypochromic
Who gets alpha and beta thalassemia and how?
Alpha - Southeast Asia and Chinese
Beta - African and Mediterranean
Hereditary
What are clinical features of alpha-thalassemia?
anywhere from silent to profound defecits
symptoms of iron deficiency
in its worst form, can cause stillbirths from hydrops fetalis
What is the clinical presentation of B-thalassemia major (Cooley anemia)?
anywhere from silent to profound defecits
sx at 4-6 months of age
anemia, growth retardation, abnormal facial structure, pathologic fx, osteopenia, bone deformities, hepatosplenomegaly, jaundice, cardiac issues
Dx of alpha thalassemia
Hct low
Hgb very low
Electrophoresis shows Hemoglobin H (confirms)
Periph smear shows target cells, poikilocytes
Reticulocytes high
Fe, ferritin normal or high
Dx of beta thalassemia
Hct very low
Hgb very low
Electrophoresis shows Hgb A2, F
Periph smear shows target cells, poikilocytes, basophilic stippling, nucleated RBCs
Reticulocytes high
Fe, ferratin normal or high
Tx of thalassemia
If Hgb H (alpha): folic acid supplements; avoid iron and oxidative drugs
If beta: transfusions, but be VERY careful of iron overload; parenternal or oral deferoxamine after; allogeneic bone marrow transplant/splenectomy
What is the pathophys of spherocytosis
RBCs are shaped like spears
Leads to premature breakdown of RBCs
Genetic
Who gets spherocytosis?
Northern Europeans
What are the symptoms of spherocytosis?
fatigue, irritability, SOB, weakness
How do you diagnose spherocytosis?
periph smear - spherocytes
bilirubin high
CBC for anemia
reticulocyte high
(COOMBs test)
How do you treat spherocytosis?
Folic acid
RBC transfusions
splenectomy
(but this doesn’t cure the RBC shape)
What are some complications of spherocytosis?
gall stones
aplastic crisis
