Nokea
A laboratory finding of aplastic anaemia
- A. Pancytopaenia
- B. Erythrocytosis
- C. Bone marrow hypercellularity
- D. Reticulocytosis
Correct Answer: A
Rationale: The correct answer is A: Pancytopenia. Aplastic anemia is characterized by a decrease in all blood cell types (red blood cells, white blood cells, and platelets), leading to pancytopenia. This is due to bone marrow failure, resulting in decreased production of blood cells. Erythrocytosis (B) is an increase in red blood cells, which is the opposite of what is seen in aplastic anemia. Bone marrow hypercellularity (C) is not typically observed in aplastic anemia, as the bone marrow is usually hypocellular. Reticulocytosis (D) is an increase in immature red blood cells and is not a characteristic finding in aplastic anemia where there is decreased production of all blood cell types.
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A 13-year-old Hispanic girl is found to have a WBC count of 6,500/mm3 with 40% Auer rod–containing granular blasts that, by flow cytometry, express very bright CD33 but are negative for human leukocyte antigen–DR isotype (HLA-DR). She is oozing blood around her peripheral IV site. Coagulation studies reveal an international normalized ratio (INR) of 3.4, a fibrinogen of 170, and a markedly elevated D-dimer. Marrow aspirate shows nearly 90% blasts with a similar morphology. You send the marrow to the fluorescence in situ hybridization (FISH) lab and request STAT testing for the most likely recurrent genetic abnormality based on the clinical presentation. How do you plan to initiate therapy?
- A. Perform a lumbar puncture to determine leukemic involvement, then proceed with induction chemotherapy.
- B. Begin therapy with all-trans retinoic acid (ATRA) immediately while aggressively managing coagulopathy with blood product support.
- C. Start dexamethasone and hydroxyurea immediately while aggressively managing coagulopathy with blood product support.
- D. Start induction chemotherapy, obtain HLA typing, and start a donor search because of the poor prognosis associated with this leukemic phenotype.
Correct Answer: B
Rationale: The correct answer is B: Begin therapy with all-trans retinoic acid (ATRA) immediately while aggressively managing coagulopathy with blood product support. In this scenario, the patient presents with acute promyelocytic leukemia (APL), characterized by the presence of Auer rod-containing blasts expressing CD33 and negative for HLA-DR. The presence of coagulopathy with elevated INR, D-dimer, and oozing blood suggests disseminated intravascular coagulation (DIC), a common complication in APL. Immediate treatment with ATRA is crucial to differentiate and mitigate the risk of DIC worsening. ATRA induces differentiation of APL blasts, resolving the coagulopathy. Aggressive management of coagulopathy with blood product support is essential to prevent bleeding complications. Lumbar puncture (choice A), dexamethasone and hydroxyurea (choice C), and starting a donor search (choice D) are not indicated as the
Blinatumomab, a bispecific T-cell engaging molecule, is active against which CD antigen that is expressed on B-lymphoblasts?
- A. CD10
- B. CD15
- C. CD19
- D. CD20
Correct Answer: C
Rationale: Step-by-step rationale:
1. Blinatumomab is a bispecific molecule designed to engage T-cells to target B-lymphoblasts.
2. It targets CD19, a B-cell-specific antigen expressed on B-lymphoblasts.
3. Engagement of T-cells via CD19 leads to targeted killing of B-lymphoblasts.
4. CD10, CD15, and CD20 are not specific to B-cells, making them incorrect choices.
Summary:
The correct answer is C (CD19) because blinatumomab's mechanism of action specifically targets B-lymphoblasts via CD19. Choices A, B, and D are incorrect as they do not have the same specificity for B-cells as CD19 does.
You are seeing a 2-year-old girl with new onset of fever and bronchitis. She has maculopapular rash and hepatosplenomegaly. Blood smear shows leukocytosis (100,000/mm3), anemia, and thrombocytopenia. Ancillary tests include fetal hemoglobin of 80% and normal blood karyotype. What is the most likely diagnosis?
- A. Leukemoid Reaction
- B. Acute lymphoblastic leukemia (ALL)
- C. Chronic myeloid leukemia (CML)
- D. Juvenile myelomonocytic leukemia (JMML)
Correct Answer: D
Rationale: The most likely diagnosis in this scenario is Juvenile myelomonocytic leukemia (JMML). This is supported by the presence of hepatosplenomegaly, maculopapular rash, leukocytosis, anemia, and thrombocytopenia in a young child. The elevated fetal hemoglobin level is characteristic of JMML. Additionally, a normal blood karyotype helps differentiate JMML from other leukemias.
Choice A (Leukemoid Reaction) is incorrect because it is typically a reactive condition due to infections, not a primary hematological malignancy like JMML. Choice B (Acute lymphoblastic leukemia) is less likely due to the presence of hepatosplenomegaly and a high fetal hemoglobin level. Choice C (Chronic myeloid leukemia) is less likely in a young child with the given clinical presentation.
A 4-year-old male child presents to the emergency department with his fourth invasive Staph infection. CBC consistently identifies moderate neutropenia. Sophisticated lab testing identifies lack of Toll-like receptor responses. The patient undergoes whole exome sequencing and is found to have pathogenic variants in IRAK4. What does 'IRAK4' stand for?
- A. Interferon gamma receptor-associated kinase 4
- B. Inducible RAS activating kinase 4
- C. Interleukin-1 receptor-associated kinase 4
- D. Immune response activating kinase 4
Correct Answer: C
Rationale: Step 1: Identify the function of IRAK4.
IRAK4 is involved in the signaling pathway of the immune system, particularly in response to interleukin-1 (IL-1) receptor activation.
Step 2: Break down the acronym IRAK4.
IRAK4 stands for Interleukin-1 Receptor-Associated Kinase 4.
Step 3: Link the information in the question to the correct answer.
Given that the patient has a lack of Toll-like receptor responses and pathogenic variants in IRAK4, it indicates a problem with the interleukin-1 signaling pathway, making choice C (Interleukin-1 receptor-associated kinase 4) the correct answer.
Summary:
A: Incorrect - Interferon gamma receptor-associated kinase does not match the function of IRAK4.
B: Incorrect - Inducible RAS activating kinase does not match the function of IRAK4.
C: Correct - Matches the function of IRAK4
An older adult patient is undergoing diagnostic testing for chronic lymphocytic leukemia (CLL). What assessment finding is certain to be present if the patient has CLL?
- A. Increased numbers of blast cells
- B. Increased lymphocyte levels
- C. Intractable bone pain
- D. Thrombocytopenia with no evidence of bleeding
Correct Answer: B
Rationale: Step-by-step rationale:
1. CLL is characterized by the proliferation of abnormal lymphocytes.
2. Increased lymphocyte levels are a hallmark of CLL due to the accumulation of these abnormal cells.
3. Lymphocytosis is a key diagnostic feature in CLL.
4. Other choices are incorrect because blast cells are characteristic of acute leukemia, bone pain is more common in multiple myeloma, and thrombocytopenia with no bleeding is not a specific finding in CLL.
Summary: Increased lymphocyte levels are certain to be present in a patient with CLL due to the abnormal proliferation of lymphocytes. Other choices are incorrect as they do not align with the characteristic features of CLL.