Hema Flashcards
(27 cards)
What is Immune Thrombocytopenic Purpura (ITP)?
An acquired disorder characterized by immune-mediated destruction of platelets and possibly inhibition of platelet release from the megakaryocyte.
What are the key clinical features of ITP?
Characterized by mucocutaneous bleeding and a low, often very low, platelet count, with otherwise normal peripheral blood cells and smear.
How is ITP diagnosed?
Diagnosis of exclusion, needing to rule out other differential diagnoses.
What are the two classifications of ITP?
Primary ITP and Secondary ITP.
What defines Primary ITP?
Absence of any other identified pathology (idiopathic) and isolated thrombocytopenia (<100 x10°/L).
What defines Secondary ITP?
Presence of other conditions such as infections (HIV or HCV), lymphoproliferative disorders, solid tumors, SLE, or Antiphospholipid Syndrome (APS).
What are the phases of ITP?
Persistent (no stable remission between 3 and 12 months) and Chronic (continuing for more than 12 months).
What is the bleeding tendency in ITP patients?
ITP patients are not really bleeders unless there are concomitant conditions like sepsis, infections, or trauma.
What are the common presentations of ITP?
Ecchymoses, petechiae, mucocutaneous bleeding, and possibly severe thrombocytopenia.
What are some specific types of bleeding associated with ITP?
Oral mucosa (gingival bleeding), gastrointestinal bleeding, menorrhagia, wet purpura (blood blisters in the mouth), ICH, and retinal hemorrhages.
What are the management goals for ITP?
Decrease reticuloendothelial uptake of the antibody-bound platelet, decrease antibody production, and increase platelet production.
What is the initial management for asymptomatic ITP patients?
Observation if platelet count is > 30 x 10°/L and no signs of impending bleeding.
What are some outpatient treatments for ITP?
Glucocorticoid (Prednisone) 1 mg/kg, RhoD immune globulin 50-75 µg/kg, IV IgG 1-2 g/kg total, given over 1-5 days.
What is the immediate treatment for severe ITP?
Glucocorticoids
Glucocorticoids increase platelet count by promoting apoptotic death of autoantibody-producing lymphocytes and downregulating macrophage activity.
What is the recommended dosage of Dexamethasone for severe ITP?
40 mg for 4 days
This regimen results in a better overall response with fewer bleeding events and does not require tapering.
What are common adverse effects of glucocorticoids?
Hyperglycemia, osteoporosis, insomnia, and infection
These side effects are important to monitor during treatment.
What is Rituximab and when is it indicated?
Monoclonal antibody against CD20; indicated for refractory ITP
It is used if there is no adequate response to glucocorticoids and splenectomy.
What is the dosing schedule for Rituximab?
100-375 mg/m2 weekly for 4 weeks
This treatment is for patients who are not candidates for splenectomy or do not want it.
What is the role of Intravenous Immune Globulin (IV IgG) in ITP treatment?
Raises platelet count within 24-48 hours
It interferes with macrophage uptake of autoantibody-coated platelets.
When is IV IgG preferred over glucocorticoids?
For active bleeding
The effect of IV IgG persists for 2-6 weeks and is given at 1-2 g/kg total over 1-5 days.
What is the primary use of RhoD Immune Globulin (RhoGam)?
Raises platelet count; only for Rh+ patients
It saturates macrophage Fc receptors with anti-D coated RBCs.
What are the contraindications for using RhoGam?
Avoid in patients with hemolysis or high risk of hemolysis
These conditions could lead to complications.
What is the preferred second-line therapy for ITP?
Splenectomy
The spleen is the major site of phagocytosis, and this procedure is delayed 6-12 months after diagnosis.
What immunizations should be given before splenectomy?
Pneumococcus, Meningococcus, and Haemophilus influenzae
These vaccinations are important to prevent infections post-splenectomy.
