Hematology Flashcards
What are the symptoms of anemia?
there is a progression from dyspnea and fatigue to lightheadedness, syncope, and chest pain
Whaat is cryoprecipitate?
a blood product used to replace fibrinogen and provides high amounts of clotting factors
When do we transfuse platelets?
- less than 10K in an asymptomatic patient
- less than 50K in a bleeding patient
Describe the etiology, symptoms, labs, and treatment of iron deficiency anemia.
- most often due to chronic blood loss or dietary deficiency, particularly with unsupplemented breast milk
- presents with koilonychia, pica, and anemia
- labs demonstrate a microcytic anemia with low ferritin, high TIBC, low saturation, and low serum iron; RDW is elevated
- treat with iron replacement
Describe the pathogenesis and labs suggestive of anemia of chronic disease.
- chronic inflammation upregulates IL-6 and thus hepcidin, which lowers iron availability
- presents with a microcytic anemia, increased ferritin, reduced TIBC, low serum iron, and low % saturation
Compare the iron studies for iron deficiency anemia and anemia of chronic disease.
- IDA: low serum iron, low ferritin, elevated TIBC, low % sat
- AOCD: low serum iron, high ferritin, low TIBC, low % sat
Describe the pathophysiology, etiology, and labs consistent with sideroblastic anemia.
- a defect in protoporphyrin synthesis that results in formation of ringed sideroblasts present on blood smear
- causes include X-linked defect in ALA synthase, alcohol’s suppressive effect on bone marrow, lead poisoning, and isoniazid or vitamin B6 deficiency
- labs demonstrate a microcytic anemia with iron overload and sideroblastic rings, which are iron-laden mitochondria around the nuclei
What is the difference between sideroblastic anemia and porphyria?
both are defects in heme synthesis, but porphyrias do not present with ringed sideroblasts on blood smear
What is the difference between a ringed sideroblast and basophilic stippling?
- ringed sideroblasts are caused by iron-lade mitochondria and seen in the bone marrow for sideroblastic anemias
- basophilic stippling is an aggregation of residual ribosomes seen in sideroblastic anemias and thalassemias but on a peripheral smear
Target cells on a peripheral smear are indicative of what diseases?
HALT:
- HbC
- Asplenia
- Liver disease
- Thalassemia
Describe the of pathophysiology, labs, and diagnosis of alpha-thalassemia.
- due to a deletion of one or more alpha-globin genes, which produces a microcytic anemia
- 1 is asymptomatic, 2 produces a mild anemia, 3 produces HbH (B4 tetrads), and 4 produces HbBarts (y4 tetrads) with hydrops fetalis and in utero death
- importantly, 3 deletions is the only microcytic anemia that is associated with an increased reticulocyte and erythrocyte count
- diagnosis is made with hemoglobin electrophoresis and genetic testing
Describe the pathophysiology and labs of B-thalassemia minor.
- a microcytic anemia caused by the deletion of one beta-globin gene, typically in Mediterraneans or Africans
- labs demonstrate a microcytic anemia, elevated HbA2 and HbF levels, and target cells
Describe the pathophysiology, presentation, lab findings, and treatment of B-thalassemia major.
- a microcytic anemia caused by the mutation of two beta-globing genes, which results in unpaired alpha chains
- these alpha chains damage RBC membranes, contributing to ineffective hematopoiesis and extravascular hemolysis
- presents with hepatosplenomegaly and crew cut sign after birth since HbF is protective
- labs demonstrate a microcytic anemia, elevated HbA2 and HbF levels, and target cells
- requires chronic transfusions
What are the etiologies and common features of all megaloblastic anemias?
- caused by folate or B12 deficiency, orotic acuduria, and Diamond-Blackfan anemia
- all are caused by impaired DNA synthesis
- they all present with macrocytic anemia, hyper-segmented neutrophils, and glossitis
Describe the pathophysiology and presentation of Diamond-Blackfan anemia.
- a megaloblastic anemia with rapid-onset in the first year of life
- due to an intrinsic defect in erythroid progenitor cells
- presents with elevated HbF, short stature, craniofacial abnormalities, and upper extremity malformations (e.g. triphalangeal thumbs)