From the Guidelines
The patient's presentation is consistent with aplastic anemia, and the most inconsistent finding with this diagnosis is the presence of lymphoblasts on peripheral blood smear. Aplastic anemia is a condition characterized by pancytopenia, bone marrow hypocellularity, and a lack of lymphadenopathy, hepatomegaly, and splenomegaly 1. The presence of lymphoblasts on peripheral blood smear is more indicative of a lymphoproliferative disorder, such as acute lymphoblastic leukemia, which is not consistent with the diagnosis of aplastic anemia.
Some key features of aplastic anemia include:
- Pancytopenia, which is a reduction in the number of red blood cells, white blood cells, and platelets
- Bone marrow hypocellularity, which is a decrease in the number of cells in the bone marrow
- Lack of lymphadenopathy, hepatomegaly, and splenomegaly
- Normal or increased reticulocyte count, which indicates an attempt by the bone marrow to produce more red blood cells
In contrast, the presence of lymphoblasts on peripheral blood smear is more indicative of a lymphoproliferative disorder, such as acute lymphoblastic leukemia. This condition is characterized by an overproduction of immature white blood cells, known as lymphoblasts, which can crowd out normal blood cells in the bone marrow.
It's worth noting that aplastic anemia can be caused by a variety of factors, including autoimmune disorders, viral infections, and exposure to toxic substances. Treatment for aplastic anemia typically involves immunosuppressive therapy, bone marrow transplantation, or supportive care to manage symptoms and prevent complications.
In terms of the other options, reticulocytosis is a normal response to anemia and is not inconsistent with aplastic anemia. Absolute neutrophil count (ANC) of 0.5 x 10^9/L is low and consistent with aplastic anemia. Low neutrophil alkaline phosphatase score is also consistent with aplastic anemia. WBC differential count showing neutrophils, lymphocytes, monocytes, eosinophils, and basophils is normal and not inconsistent with aplastic anemia.
Overall, the presence of lymphoblasts on peripheral blood smear is the most inconsistent finding with the diagnosis of aplastic anemia, and further evaluation and testing would be needed to determine the underlying cause of this finding.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Aplastic Anemia
- Aplastic anemia is defined as pancytopenia with hypocellular bone marrow without signs of marrow fibrosis or presence of abnormal cells 2.
- Most acquired aplastic anemia is the result of immune-mediated destruction of hematopoietic stem cells causing pancytopenia and an empty bone marrow, which can be successfully treated with either immunosuppressive therapy or hematopoietic stem-cell transplantation 3.
- The choice of frontline therapy is determined by a number of factors including AA severity, age of the patient, donor availability, and access to optimal therapies 4.
Diagnosis and Treatment
- Diagnosis of AA requires a comprehensive approach with prompt evaluation for inherited and secondary causes of bone marrow aplasia, while providing aggressive supportive care 4.
- For newly diagnosed severe aplastic anemia, bone marrow transplant should be pursued in all pediatric patients and in younger adult patients when a matched sibling donor is available 4.
- Frontline therapy in older adult patients and in all patients lacking a matched sibling donor involves immunosuppressive therapy (IST) with horse antithymocyte globulin and cyclosporine A 4.
Pathophysiology
- An immune basis for most patients with aplastic anemia (AA) provides a rationale for immunosuppressive therapy (IST) 5.
- Recent advances in understanding the pathogenesis of AA have identified defective telomere maintenance as an important explanation for the onset of marrow failure, relapse and clonal evolution after IST, in some patients with AA 5.
Clinical Presentation
- Aplastic anemia can present with symptoms such as dyspnea, pallor, petechiae, and fatigue due to pancytopenia 2.
- Laboratory findings include hypocellular bone marrow, pancytopenia, and low reticulocyte count 2.