MAHA and Thrombocytopenia Flashcards
classic hematological finding on the PBS of maha
schistocytes. caused by damaged vascular endothelium.
reasons behind MAHA
TTP, HUS, DIC, HELLP, and hypertensive crises.
what indicate MAHA on the CBC
thrombocytopenia, low Hb.
Markers of hemolysis anemia
increased LDH, increased bilirubin, low haptoglobin
What must you rule out to diagnose MAHA
Negative DAT/coombs test which rules out autoimmune hemolysis
TTP is caused by a deficiency of ____ needed to cleave ultralarge ____ multiverses. These multiverses aggregating can cause uncontrolled platelet agglutination.
Acquired ___ deficiency is typically due to inhibition by an ____
TTP is caused by a deficiency of ADAMTS13 needed to cleave ultralarge WVF multiverses. These multiverses aggregating can cause uncontrolled platelet agglutination.
Acquired deficiency is typically due to inhibition by an autoantibody.
Primary clinical diagnosis when a patient presents with thrombocytopenia and MAHA without an alternative explanation
TTP
Lab findings of TTP
MAHA: schistocytes Increased LDH Thrombocytopenia Increased bilirubin Decreased haptoglobin. Decreased ADAMTS13 activity. PT, PTT normal
T/F in TTP, PT and PTT are elevated
False. Nothing is wrong with clotting, it’s causing aggregation of VWF and platelet agglutination (factors aren’t actually doing anything).
PT/INR and PTT is normal
treatment of TTP
It’s a medical emergency.
Daily plasma exchange is required, and steroids or immunosuppressive therapy is used in addition.
Platelet transfusions are done in TTP?
No. Platelet transfusions are avowed in TTP and may be dangerous as it provides fuel for the development of thrombosis.
HUS caused by ____
Shiga toxin, or some types of ecolI
Consider HUS if person has diarrhea and also thrombocytopenia/maha
Just like TTP, HUS needs plasma exchange?
FALSE. HUS is supportive. It will go away, unlike TTP which has an inherent problem with ADAMTS13, shiga toxin might temporarily bind to ADAMTS13 to make it look like TTP but antibiotics will help
_____ is a syndrome of unregulated systemic coagulation, which results in widespread deposition of fibrin clots in blood vessels. Results in consumption of platelets and coagulation factors, resulting in ___ ___ as well as compromised blood flow due to ____ which can ultimately lead to tissue ____ and organ damage.
DIC is a syndrome of unregulated systemic coagulation, which results in widespread deposition of fibrin clots in blood vessels. Results in consumption of platelets and coagulation factors, resulting in EXCESSIVE BLEEDING as well as compromised blood flow due to THROMBOSIS which can ultimately lead to tissue ISCHEMIA and organ damage.
DIC can be considered as a 3 step process.
- Release of large amounts of tissue factor stimulates the extrinsic pathway by activating
FVII - Excessive thrombin production and defective physiologic anticoagulant mechanisms.
There is a reduced production and increased consumption of antithrombin, protein C,
protein S and tissue factor pathway inhibitor. - Suppression of fibrin clot degradation due to inhibition of fibrinolysis
DIC is associated with thrombocytopenia and MAHA as well as _____ PT/INR, ____ PTT and _____ fibrinogen and ____ D-Dimer
DIC is associated with thrombocytopenia and MAHA as well as INCREAED PT/INR, INCREASED PTT and DECREAED fibrinogen and INCREASED D-Dimer
HELLP REFERES TO A SYNDROME characterized by ___, ___ liver enzymes and ____ platelet count in obstetrical patients.
HELLP REFERES TO A SYNDROME characterized by MAHA, ELEVATED liver enzymes and DECREASED platelet count in obstetrical patients.
T/fMAHA is immune
False. It’s a non-immune intravascular hemolysis. Defined by the presence of RBC fragments on peripheral blood smear.
Name thrombotic microangiopathies vs system disorders with MAHA
Thrombotic microangiopathies: TTP, HUS
systemic: HELLP, DIC
Not all MAHA is caused by a thrombotic microangiopathies, but nearly all thrombotic microangiopathies cause MAHA and thrombocytopenia.
Lab testing for MAHA
- PBC— schistocytes
- CBC— anemia (low Hb) and thrombocytopenia (decreased platelets)
- Negative DAT (non-immune) Rules out autoimmune hemolytic anemia
- Increased LDH (indicates hemolysis), increased total and indirect (bilirubin) (increased RBC turnover), decreased haptoglobin
- Other testing to look for systemic disorders (ex/ DIC may have low fibrinogen and high D-Dimer)
In HUS, is there a deficient ADAMTS13?
NO. It looks like there is a decreaed in ADAMTS13, but there is actually a sufficient concentration. Shiga toxin is preventing it from doing it’s job though, causing platelet agglutination.
Compare and contrast HUS vs TTP in terms of age of onset, presence of diarrheal illness, and clinical tetrad/pentad
HUS: Age: child bc of shiga or ecolI - present diarrhea illness HUS TETRAD - MAHA - mild/moderate thrombocytopenia - acute kidney FAILURE - MILD neurological symptoms - LABS: Shiga toxin, ADAMTS13 normal
TTP”
Age; adults. No diarrheal illness
Clinical Pentad:
- MAHA
- severe thrombocytopenia
- acute kidney INJURY
- SEVERE neurological symptoms
- fever
- ADAMTS13 SEVERELY reduced, no shiga toxin
Clinical symptoms of acute DIC and chronic DIC
Acute DIC: profound system bleeding (no protein C, no protein S or antithrombin), and MAHA, and Tissue ischemia/multiorgan dysfunction (because thrombin activation is through the roof at the same time, causing clots and shearing everywhere)
Chronic DIC: SPECTRUM because of continuous release of small amounts of TG. Minor mucocutaneous bleeding or arterial/venous thrombosis (VTE)
Most common cause of chronic DIC
Solid tumors
DIC treatment
- treat underlying cause
- if bleeding: platelet transfusion if platelets less than 50. Frozen plasma if PTT >1.5 ULN and cryoprecipitate if fibrinogen is <1.5
T/F should use heparin for DIC to overcome clots
False. Higher risk of increased bleeding if heparin used in Acute DIC
HELLP syndrom
Hemolysis with a microangiopathic blood smear
ELEVATED LIVER enzymes
LOW PLATELETS in obstetrical patients.
