RBCs & Anemias
This parameter is the most important for assessing oxygen carrying capacity and is used to diagnose anemia.
What is hemoglobin concentration?
This lab test measures the extrinsic pathway function and is used for warfarin monitoring.
What is PT (Prothrombin Time)?
This benign WBC disorder is characterized by an absolute neutrophil count greater than 7,000/μL and can be caused by infection, steroids, or acute MI.
What is neutrophilia?
This is the committed step of heme synthesis that combines glycine and succinyl CoA to form ALA.
What is ALA synthase (step 1)?
This antiplatelet drug works by irreversibly inhibiting COX1 to prevent TXA production and is commonly used in low doses for secondary prevention of cardiovascular disease.
What is aspirin?
These red blood cells appear as small, round cells without central pallor and are pathognomonic for the most common hereditary hemolytic anemia.
What are spherocytes (seen in hereditary spherocytosis)?
This most common inherited bleeding disorder affects von Willebrand factor and presents with prolonged bleeding during procedures and menorrhagia.
What is von Willebrand Disease?
This chromosome abnormality, also called the Philadelphia chromosome, involves translocation t(9;22) and is pathognomonic for this chronic myeloid neoplasm.
What is CML (Chronic Myeloid Leukemia)?
This tick-borne parasite causes the characteristic "maltese cross" appearance on blood smear and can cause hemolytic anemia in immunocompromised patients.
What is Babesia?
Unlike clopidogrel and prasugrel, this P2Y12 receptor antagonist REVERSIBLY inhibits ADP-induced platelet aggregation.
What is ticagrelor?
This mnemonic "TAILS" helps remember the five causes of microcytic anemia, where the "A" stands for this condition that is the most common anemia in hospitalized populations.
What is anemia of chronic disease?
This anticoagulant works by binding antithrombin and inhibiting both thrombin and Factor Xa, with efficacy monitored by aPTT.
What is heparin?
This acute leukemia subtype is associated with t(15;17) translocation, DIC complications, and has an excellent prognosis when treated with ATRA (all-trans retinoic acid).
What is APML (Acute Promyelocytic Leukemia)?
Lead poisoning inhibits these two enzymes in heme synthesis, leading to accumulation of ALA and causing sideroblastic anemia.
What are ALA dehydratase and ferrochetalase?
This transfusion reaction occurs within 6 hours, presents with hypoxemia and bilateral infiltrates, and is caused by donor antibodies activating recipient PMNs in the lungs.
What is TRALI (Transfusion-Related Acute Lung Injury)?
In sickle cell disease, symptoms don't appear until 6 months of age because this type of hemoglobin, which doesn't sickle, predominates in fetal and early infant life.
What is hemoglobin F (HbF) or fetal hemoglobin?
In this condition, antibodies against ADAMTS13 lead to deficiency of this enzyme, causing large vWF multimers that result in platelet activation and microthrombi formation, presenting with the pentad of fever, renal failure, neurologic symptoms, thrombocytopenia, and hemolytic anemia.
What is TTP (Thrombotic Thrombocytopenic Purpura)?
This myeloproliferative neoplasm presents with JAK2 mutation, splenomegaly, teardrop cells on blood smear, and bone marrow fibrosis with clusters of atypical megakaryocytes.
What is Primary Myelofibrosis (PMF)?
This Plasmodium species has a special affinity for reticulocytes, only uses the DARC receptor for invasion, and has a latent hepatic form capable of reactivation.
What is Plasmodium vivax?
This test determines the presence of antibodies on red blood cells and would be newly positive in delayed hemolytic transfusion reactions.
What is the Direct Antiglobulin Test (DAT)?
A 25-year-old African American male presents with fatigue and dark urine after taking trimethoprim-sulfamethoxazole for a UTI. Laboratory studies show hemoglobin 8.5 g/dL (normal 13.5-17.5), elevated LDH, and bite cells on peripheral smear. The underlying enzyme deficiency in this condition affects which metabolic pathway, and what is the primary cellular consequence that leads to hemolysis?
What is glucose-6-phosphate dehydrogenase (G6PD) deficiency affecting the hexose monophosphate shunt (pentose phosphate pathway), leading to inability to regenerate reduced glutathione and subsequent oxidative damage to hemoglobin and red blood cell membranes?
A 45-year-old woman presents with recurrent DVTs and a history of multiple miscarriages. Lab studies show a prolonged aPTT that does not correct with mixing studies. She tests positive for lupus anticoagulant and anticardiolipin antibodies. Which of the following best explains the mechanism of her thrombotic tendency?
What is Autoantibodies against phospholipids interfering with the phospholipid-dependent coagulation reactions?
(This describes Antiphospholipid Antibody Syndrome, which is associated with lupus and causes both arterial and venous thromboses plus recurrent miscarriages due to acquired autoantibodies against phospholipids.)
A 45-year-old male presents with fatigue, splenomegaly, and a CBC showing WBC 150,000 with basophilia. Bone marrow biopsy reveals <20% blasts. The patient is started on imatinib and shows excellent response. However, 3 years later, he develops worsening fatigue and repeat labs show 25% blasts in bone marrow. This represents progression to which phase of his underlying disease, and what are the two possible acute leukemia subtypes he could develop in a 2:1 ratio?
What is blast phase (or blast crisis) of CML, and what are AML (2/3 of cases) and ALL (1/3 of cases)?
A 45-year-old construction worker presents with abdominal pain, psychiatric symptoms, and wine-colored urine. Laboratory studies show elevated ALA levels. His condition worsens after starting phenytoin for seizures. The patient most likely has a deficiency in which of the following enzymes?
What is Porphobilinogen deaminase (acute intermittent porphyria - explains the "WIPAIN" symptoms: Wine-colored urine, Inducers of P450 like phenytoin worsening symptoms, Psychiatric symptoms, Autonomic dysregulation, Intense abdominal pain, and Neuropathy)?
This intravenous GPIIbIIIa antagonist has a quick onset and offset, reversibly binds to block fibrinogen binding, and is used during PCI procedures.
What is eptifibatide?