Reactive Leukocyte Disorders Flashcards
Define neutropenia and agranulocytosis and list important causes for each.
Neutropenia is defined as absolute neutrophils count (ANC) of less than 1800/microliters. Agranulocytosis is defined as ANC less than 500.It can be due inadequate production or ineffective production:
* Suppression of hematopoietic stem cells - Aplastic anemia, radiation Suppression of committed granulocytic precursors Drugs Dose dependent –alkylating agents, antimetabolites. This is often reversible.
Idiosyncratic –chloramphenicol, aminopyrine, sulfonamides, chlorpromazine, phenylbutazone, thiouracil. This is often non reversible.
- Large granular lymphocyte leukemia
- Congenital
- Ineffective hematopoiesis - Megaloblastic anemia, myelodysplastic syndromes
Or it can be due to increased destruction: - Immune mediated -idiopathic, drug-induced.
- Splenic sequestration
- Increased margination
Define neutrophilia and list important causes for it
Absolute neutrophil count (ANC) >7000/μLIncreased granulopoiesis:
* Infections –primarily bacterial Immunological inflammatory
* Neoplasia Myeloproliferative neoplasms Paraneoplastic
* Drugs –colony stimulating factors
Increased release from marrow stores
* Endotoxemia
* Infection
* Hypoxia Decreased margination
* Exercise
* Catecholamines Decreased extravasation into tissues
* Glucocorticoids
Discuss the pathophysiology of leukocyte adhesion deficiency, chronic granulomatous disease, Chediak-Higashi syndrome, and myeloperoxidase deficiency
Enumerate the three main histologic types of lymph node hyperplasia with examples
- Follicular hyperplasia
- Paracortical (interfollicular) hyperplasia
- Sinus histiocytosis
- Mixed pattern of hyperplasia
Discuss the pathologic features of lymphadenopathy related to toxoplasmosis
We see a mixed pattern of hyperplasia, there is marked follicular hyperplasia, epitheloid granulomas and sinusoidal dilation with monocytoid B cells.Epitheloid granulomas consists of small and large histiocytic aggregates with germinal centersand interfollicular areas.
Explain the possible reasons that can give rise to eosinophilia.
- Allergic disorders
- Parasitic infections
- Malignant neoplasms
- Drugs (IL-2)
- Collagen vascular disorders
Explain the possible reasons that may give rise to basophilia in a patient.
- Neoplasms - CML
- Allergic disorders
- Inflammation
- Endocrine disorders
Explain the possible reasons that can lead to the development of monocytosis.
- Chronic infections
- Inflammation
- Collagen vascular disorders
- Neoplasms
- Inflammatory bowel disease
What is the definition of lymphocytosis?
Absolute lymphocyte count > 4000/μL (adults) or > 7000/µL (children) or > 9000/µL (infants)
What are the most common reasons for the development of lymphocytosis in patients?
- Viral infections
- Acute bacterial infection - only with whooping cough
- Chronic bacterial infections - only with TB and brucellosis
- Lymphoproliferative diseases
What are atypical lymphocytes?
Aka Downey cells, these are seen in viral infections such as EBV. They have a characteristic appearence.Atypical lymphocytes are clinically seen in a variety of viral illnesses but as far as STEP is concerned it is only associated with EBV.
How can we differentiate between a basophil and an atypical lymphocyte?
Basophils has a much higher nucelus to cytoplasm ratio as shown.
Define lympohocytopenia and explain why does it develop?
Absolute lymphocyte count < 1500/μL (adults) or < 3000/µL (children)Usually due to decrease in CD4+ helper T-cells
Explain the possible etiologies for the development of lymphocytopenia.
Decreased production
- Congenital and acquired immunodeficiency syndromes
- Hodgkin lymphoma Increased destruction
- Radiation, chemotherapy
- Antilymphocyte globulin
- Steroids, ACTH
- AIDS Increased loss of lymphocytes
- Damage to lymphatics and loss of lymph –protein losing enteropathy, Whipple disease, increased central venous pressure
Explain follicular hyperplasia.How does it look like?
Increased number of and larger size of secondary follicles
- Infection Systemic inflammatory disorders
- Rheumatoid arthritis
- Drug reaction
- AIDS
- Differential diagnosis includes follicular lymphoma
