Thrombocytopenia/ITP/TTP/HUS/HSP/Thrombocytosis
What is the platelet count of someone with thrombocytopenia that is asymptomatic?
100-150
What is the acceptable platelet baseline count?
150
What is normal platelet count?
150,000-450,000
What is the platelet count of someone with thrombocytopenia that has easy bruising and post traumatic bleeding?
50-100
What is acute tx for thrombocytosis?
81 mg tablets of ASA for vasomotor sxs Bleeding: D/C platelet anti-aggregating agent, ASA, and NSAIDs Thrombosis: if plt ct is > 800 tx with platelet apheresis + platelet lowering agent (goal plt ct is < 400)
What is the most common age group for pts with HSP?
90% of pts are < 10 yo seen in ages 3-12
What is the most common age group for pts presenting with HUS?
< 5 yo
What is the mortality rate for pts with HUS and what do the mortality causes include?
< 5% proteinuria, renal insufficiency, and HTN
What is the leading cause of HUS?
E Coli 0157:H7
What may stool cultures show in HUS?
E coli 0157:H7
What sxs are more common in kids with HSP?
GI sxs
What vasomotor sxs present with thrombocytosis?
HA, dizziness (inc. viscosity, dec. oxygen in circulation) visual disturbances atypical CP limb dysesthesia erythromelalgia
What are the acute tx needs for a pt with HUS?
HTN and seizure control
What is evidence of anemia in HUS?
Hgb < 8
What is the most common antibody involved in HSP?
IgA
Are stool cultures always accurate when diagnosing HUS?
NO. culture will be positive in more than 90% of pts during the first week of illness then after the first week it is only positive in 30% of patients
Can steroids help prevent the development of renal disease in HSP?
NO. once renal dz has been established they can be effective with treating sxs
What are the 4 T's in HIT workup?
T-penia, Timing of onset, Thrombosis, other cause
Can neurologic sxs present with HUS?
YES. primarily seizure stroke and coma may occur with significant mortality
What is the definition of thrombocytosis?
a platelet count > 450,000
When can howell jolly bodies and target cells present?
a pt with asplenia
What is the definition of HSP?
a systemic small vessel IgA immune complex mediated Vasculitis
What are acute manifestations of ITP?
abrupt appearance of petechiae and purpura of skin and mucous membranes
To exclude causes of reactive thrombocytosis what must you examine specifically for when evaluating for ET?
acute blood loss, iron deficiency, infection, inflammation, medication use, asplenia, malignancy, trauma
What can help to distinguish polyarteritis Nodosa for HSP?
an arteriography or MRA
What should be avoided in the tx of HUS when E coli 0157:H7 is present?
antibiotic and antimotility agents
What are some causes of immune destruction causing increased platelet destruction?
autoimmune (ITP, SLE, CLL, lymphomas); drug induced antibodies; infections (HIV); alloantibodies
What is idiopathic thrombocytopenia purpura (ITP)
autoimmune disorder caused by circulating antiplatelet autoantibodies
What is diagnosis of HSP based on?
biopsy and finding IgA in the affected vessels
What are some symptoms of thrombocytopenia?
bleeding: into superficial sites (skin, mucosa, epistaxis, conjunctiva, gingiva); easy bruising, wet bleeding, dry bleeding
What can be given for severe anemia in HUS pts?
blood transfusions
What is the first line treatment for pts with ITP?
corticosteroids: high dose prednisone or dexamethasone for 4-6 cycles
What is spurious thrombocytosis?
cytoplasmic fragments in pts with leukemia or lymphoma or severe hemolysis or burns can be counted falsely as platelets
What can thrombocytopenia be caused by?
decreased platelet production, increased platelet destruction, hypersplenia sequestration
Where does palpable purpura typically present in HSP?
dependent areas, especially BLEs and area subjected to pressure
What are the chronic tx needs for a pt with HUS?
dialysis may be required for anuric or oliguric renal failure
What are the clinical manifestations of hemolytic uremia syndrome?
diarrhea in 90% of cases and bloody diarrhea in 75% of cases abdominal pain, vomiting and fever
What are alternate anticoagulants used in the treatment of HIT?
direct thrombin inhibitors: Argatroban, ; Lepirudin Bivalirudin warfarin
What are some causes of nonimmune destruction causing increased platelet destruction?
disseminated intravascular coagulation (DIC); thrombotic microangiopathies (TTP, HUS); massive transfusions; prosthetic valve dvcs
What are other common causes of HUS in kids and adults?
drugs: quinine, cyclosporine Infection: salmonella, Shigella HIV Pneumococcal infection
What lab studies indicate hemolysis?
elevated, reticulocyte count, LDH, indirect bilirubin, and BUN/creat
What is "wet bleeding"?
epistaxis, mucosa, gingiva, GI, GU, and around IV sites
What is the chronic tx for a HSP patient?
even if renal involvement isn't present after initial episode, urinalysis and BP should be checked ever 2 to 4 weeks for the 1st 6 months to detect for renal disease
What is reactive thrombocytosis driven by?
excessive cytokines induced by various stimuli such as trauma or inflammation
What is the gold standard lab test for diagnosing HIT?
functional SRA (serotonin release assay)
What is the most common cause of acute renal failure in children?
hemolytic uremic syndrome
What can be commonly seen on a peripheral smear in a pt with thrombocytosis?
howell-jolly bodies and tear drop RBCs
What is the most common cause of thrombocytopenia?
increased platelet destruction
What is the tx for HUS?
largely supportive
What is the acute treatment for ITP?
may resolve spontaneously; or use steroids or splenectomy
What is the patient demographics for thrombocytosis?
median age at dx is 60 yo females > males
In a pt that has ITP what may a peripheral smear of bone marrow biopsy show?
megakaryocytes
What triad is HUS characterized by?
microangiopathic hemolytic anemia, thrombocytopenia, and severe renal failure
What is most pts chief complaint with TTP?
non-specific constitutional symptoms (nausea/vomitting/abdominal pain)
What is seen on a peripheral blood smear in a pt with TTP?
numerous RBC fragments: schistocytes
What is the initial presentation of thrombotic thrombocytopenia purpura (TTP)?
often begins flu-like followed by clinical and lab abnormalities
What is thrombocytosis caused by?
overproduction of platelets (reactive thrombocytosis) clonal expansion of megakaryocytes (clonal thrombocytosis)
What sxs are more common in adults with HSP?
palpable purpura
What is the 4 ACR criteria for diagnosis HSP?
palpable purpura (non-thrombocytopenic) Age < 20 yrs at onset of 1st symptom bowel angina or ischemia granulocytic infiltration of arteriole or venule walls on biopsy (a presence of 2 of the following for diagnosis)
What is the tetrad for HSP?
palpable purpura, abdominal pain, renal disease, and arthritis/arthralgias
What is "dry bleeding"?
petechia, ecchymoses
What is the definition for "low platelet count" in thrombocytopenia?
platelet count of less than 150,000
What is required for the diagnosis of ET?
platelet counts > 600,000 on 2 separate occasions > 4 weeks apart absence of the Philadelphian chromosome (r/o CML) exclusion of secondary causes need to repeat CBC w/ peripheral smear and bone marrow biopsy to exclude spurious thrombocytosis
What is the platelet count indicated for thrombocytopenia in HUS?
plt usually < 60,000
What is the acute tx for HSP?
prednisone daily for 2 weeks - typically for severe arthritis and/or abdominal pain
when can tear drop cells, nucleated RBC and WBC precursors present?
pt with PMF
What is unique about the palpable purpura that is essential for the diagnosis of HSP?
purpura must be unrelated to thrombocytopenia
What are clinical manifestations related to TTP?
purpura, jaundice, pallor from hemolysis, mucosal bleeding, fever, fluctuating levels of consciousness
What is erythromelalgia?
rare condition affecting feet > hands intense burning pain, severe redness, and increased skin temp
Which thrombocytosis is more frequent, reactive or clonal?
reactive
Does reactive thrombocytosis need treatment?
reactive is rarely associated with thrombosis or bleeding and generally does not require specific treatment
What are end stage clinical manifestations related to TTP?
renal failure and neurologic events
What symptoms are seen in a person with thrombocytopenia that has a platelet count of 20-50?
risk for serious, excessive post-traumatic bleeding
What would present on a peripheral smear of a patient with HUS?
schistocytes, burr cells, and helmet cells
What are you looking for in a physical exam when evaluating someone for thrombocytopenia?
special focus on LAD and hepatosplenomegaly signs of lymphoma, hepatic disease, connective tissue dz, infectious disease
What is the chronic treatment for thrombocytosis?
strategies are based on risk factors for thrombosis smoking cessation and obesity management Low dose ASA (may be effective in preventing vascular events; blood clots) Cytoreductive therapy: hydroxyurea + ASA
What is the etiology of HSP?
supposedly exposure to a trigger antigen that causes antibody formation there is an antigen-antibody immune complex that forms and deposits in the arteriole and capillary walls of the skin, renal mesangium, and GI tract
If a kid tests positive for E coli 0157:H7 what should you do?
tell the kid to not return to school until 2 consecutive stool tests come back negative for the organism
What does criteria is needed to diagnose a pt with TTP?
the presence of hemolytic anemia and thrombocytopenia without any other cause
Why would you want to order a Coombs test in a HUS pt?
to rule out autoimmune causes of hemolytic anemia
What is the etiology of ineffective thrombopoiesis?
toxins (alcohol, cocaine, cytotoxins, XRT); drugs (thiazides, estrogens, sulfas, immune therapy); acute viral infections (acute hepatitis, HIV, EBC, rubella); nutritional deficiencies (Vit B12, folate or iron deficiencies)
How do arthralgias and arthritis present in HSP?
typically oligoarticular (few joints), affecting LE and large joints
What is the clinical presentation of thrombocytosis?
vasomotor sxs, thrombotic and bleeding complications
What is the prognosis for HSP?
very good and most patients have spontaneous recovery within 4 weeks
When does renal involvement start to preset in HSP patients?
within 1st month of illness
