White Blood Cell Functions and Hematopoiesis

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Questions and Answers

Which of the following diseases can result in neutrophilia?

Hairy cell leukemia

Tuberculosis (correct)

Rheumatoid arthritis (correct)

Aplastic anemia

What condition is associated with a lack of leukocyte adhesion proteins, leading to increased susceptibility to infections?

Leukocyte Adhesion Deficiency (correct)

Pelger-Huet Anomaly

Chediak-Higashi Syndrome

Chronic Granulomatous Disease

In which condition do neutrophils retain the ability to phagocytose but are unable to kill microorganisms?

Myelodysplastic Syndrome

Chronic Granulomatous Disease (correct)

Pelger-Huet Anomaly

Chediak-Higashi Syndrome

Which of the following is NOT a potential cause of monocytopenia?

Influenza Signup and view all the answers

What characteristic shape do neutrophils exhibit in Pelger-Huet Anomaly?

Bilobed Signup and view all the answers

Which autoimmune disease is commonly associated with neutrophilia?

Rheumatoid arthritis Signup and view all the answers

What type of genetic mutation is associated with Chediak-Higashi Syndrome?

Inherited genetic mutation Signup and view all the answers

Which of the following is a characteristic of Chronic Granulomatous Disease?

Absence of respiratory burst Signup and view all the answers

Basophilia can be associated with which of the following?

Surgical complications Signup and view all the answers

Which is a common treatment for conditions causing monocytopenia?

Myelotoxic drugs Signup and view all the answers

What is a common cause of absolute lymphocytosis?

Acute viral infections Signup and view all the answers

Which condition is NOT associated with relative lymphocytosis?

Chronic lymphocytic leukemia Signup and view all the answers

What does the term neutrophilia refer to?

Increase in the number of neutrophils Signup and view all the answers

Infectious mononucleosis is primarily caused by which virus?

Epstein-Barr virus Signup and view all the answers

Which clinical feature is characteristic of infectious mononucleosis?

Diagnostic red spots at the junction of soft and hard palate Signup and view all the answers

What is the normal range of leukocytes in peripheral circulation?

4000 to 11,000/μL of blood Signup and view all the answers

What is the blood picture typically seen in infectious mononucleosis?

Leucocytosis with an absolute increase in lymphocytes Signup and view all the answers

Which type of white blood cell is primarily affected in neutrophilia?

Neutrophils Signup and view all the answers

Which of the following is a cause of relative lymphocytosis?

Exercise Signup and view all the answers

What is a common threshold for defining neutrophilia?

More than 8000 cells/μL Signup and view all the answers

Which factor is NOT typically related to absolute lymphocytosis?

Splenic sequestration Signup and view all the answers

Which of the following conditions could lead to neutrophilia?

Bacterial infections Signup and view all the answers

What is the clinical significance of diagnosing neutrophilia?

Can signal an underlying inflammatory process Signup and view all the answers

Which of the following statements about infectious mononucleosis is true?

It can lead to lifelong immunity after infection. Signup and view all the answers

Monocytosis is often associated with what condition?

Chronic inflammation Signup and view all the answers

Neutrophilia can be associated with which of the following types of leukocyte disorders?

Leukocytosis Signup and view all the answers

Which of the following is NOT a cause of absolute lymphocytosis?

Splenomegaly Signup and view all the answers

In neutrophilia, which of the following could be a potential diagnostic strategy?

Bone marrow biopsy Signup and view all the answers

Which type of leukocytosis specifically involves an increase in neutrophils?

Neutrophilia Signup and view all the answers

Which of the following is a severe form of neutropenia?

Agranulocytosis Signup and view all the answers

What physiological condition can lead to neutrophilia?

Pregnancy Signup and view all the answers

Which drug is known to increase neutrophil release from the bone marrow?

Corticosteroids Signup and view all the answers

Which condition is a common cause of reactive neutrophilia?

Acute bacterial infection Signup and view all the answers

What is a potential cause of neutrophilia associated with metabolic diseases?

Acute renal failure Signup and view all the answers

In which type of leukemia could neutrophilia be frequently observed?

Chronic myeloid leukemia Signup and view all the answers

What is a common clinical manifestation seen alongside reactive neutrophilia?

Deviated leukocyte formula (leukemoid reaction) Signup and view all the answers

Which of these is NOT a characteristic of physiological neutrophilia?

Persistent over time Signup and view all the answers

Which immune response is closely linked to the phenomenon of neutrophilia?

Increased tissue infiltration Signup and view all the answers

What condition can cause metabolic disturbances leading to neutrophilia?

Diabetic ketoacidosis Signup and view all the answers

Which of the following conditions can be exacerbated by neutrophilia?

Gout Signup and view all the answers

Study Notes

Alterations in White Blood Cells

White blood cells (WBCs) are crucial for defending against disease, primarily operating outside the bloodstream.
WBCs exhibit key functions including margination, rolling, adhesion, transmigration (diapedesis), and chemotaxis.

Hematopoiesis

Hematopoiesis is the process of blood cell formation.
The process begins with a pluripotent stem cell, which differentiates into myeloid and lymphoid stem cells.
Myeloid stem cells generate granulocytes, megakaryocytes, and erythrocytes.
Lymphoid stem cells generate B cells and T cells which mature into plasma cells and various T-cells.
Common Fate Unit (CFU) cells are intermediates in the development process

Functions of WBCs

WBCs primarily function to protect against disease.
They actively work outside the bloodstream.
WBCs participate in key processes like margination, rolling, and adhesion, and transmigration.
WBCs use chemotaxis to navigate toward infection sites.
Phagocytosis involves recognition, engulfment, killing, and digestion of pathogens by neutrophils and monocytes (active phagocytes)

Lysosomal Constituents

Lysosomes contain enzymes for breaking down foreign particles.
Primary lysosomes (azurophilic, non-specific) contain myeloperoxidase, lysozyme (bacteria targeted), and acid hydrolases.
Secondary lysosomes (specific) contain lactoferrin, lysozyme (again bacteria), alkaline phosphatase, and collagenase.

Benign Disorders of White Blood Cells

Benign white blood cell disorders can be categorized as either qualitative (morphological or functional changes) or quantitative (changes in number).

Quantitative Disorders of White Blood Cells

Leukocytosis involves an increased number of white blood cells.
The normal range of leukocytes in peripheral blood is 4000 to 11,000/μL.
Leukopenia describes a reduced number of white blood cells.
Specific types of leukopenia include neutropenia (low neutrophils) and lymphopenia (low lymphocytes).
Related terms include leukocytosis, neutrophilia, eosinophilia, basophilia, lymphocytosis, monocytosis and their respective decreased counterparts.

Neutropenia

Neutropenia is specifically a reduced neutrophil count (less than 1500 cells/μL).
Agranulocytosis denotes severe neutropenia (neutrophil count less than 200 cells/μL).
Neutropenia has congenital (e.g., Kostmann's syndrome) and acquired causes (e.g., accelerated removal, increased destruction, drug-induced granulocytopenia, irradiation, autoimmune disorders, splenomegaly).
Acquired neutropenia includes various conditions like Felty's syndrome, neoplasms, alcoholism, and nutritional deficiencies (folate, vitamin B12, iron, copper).
Aplastic anemia and idiopathic neutropenia are also included.

Neutrophilia

Physiological causes include newborns, pregnancy, labor, postpartum, and post-exercise.
Drug-induced neutrophilia can be caused by corticosteroids.
Other causes include acute poisoning with heavy metals (Hg) and some venoms.
Reactive neutrophilia results from increased neutrophil release from bone marrow to accommodate high tissue affinity, often accompanied by leukocyte formula deviation ("leukemoid reaction").
Metabolic and endocrine diseases (diabetic ketoacidosis, acute renal failure, acute gout) and some malignant hematologic diseases (CGL, PV, CMML) are also potential causes

Eosinophilia

Eosinophilia is an increased blood eosinophil count.
Potential causes include allergic diseases (asthma, allergic rhinitis, eczema, atopic dermatitis), parasitic infections, fungal and other infections, tuberculosis, and hematologic and non-hematologic malignancies.

Lymphocytosis

Lymphocytosis is an elevated lymphocyte count.
Absolute lymphocytosis has causes like acute viral infections (infectious mononucleosis, hepatitis, cytomegalovirus), other acute infections (pertussis), protozoal infections (toxoplasmosis), and chronic intracellular bacterial infections (tuberculosis, brucellosis), and chronic lymphocytic leukemia.
Relative lymphocytosis causes include age less than two years, acute viral infections, connective tissue diseases, splenomegaly with splenic sequestration of granulocytes, exercise, and stress.
Infectious mononucleosis, caused by Epstein-Barr virus, is characterized by virus infection of epithelial and B cells; saliva from infected persons is the chief mode of transmission. The condition often does not cause illness in children below age 10 and confers lifelong immunity afterward.

Monocytosis

Monocytosis is an elevated level of monocytes.
Chronic inflammation, infections (tuberculosis, brucellosis), autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis), malignancies (Hodgkin's disease, certain leukemias), and recovery from neutropenia or acute infections are frequent causes.

Monocytopenia

Monocytopenia is characterized by low monocyte levels.
Potential causes include acute infections, stress, aplastic anemia, hairy cell leukemia, acute myeloid leukemia, treatment with myelotoxic drugs, and treatment with glucocorticoids.

Basophilia

Basophilia, an increased basophil count, could result from a surgery complication (e.g., splenectomy), infectious disorders (Influenza, Chickenpox), infected organ sites (abscesses), inflammatory disorders, and neoplastic disorders (acute myeloid leukemia, Hodgkin's disease).
Further causes of basophilia include allergic/collagen autoimmune disorders, congenital/developmental disorders, hereditary/familial/genetic disorders (e.g., spherocytosis), vegetative/autonomic/endocrine disorders (e.g., hypothyroidism), a leukemoid reaction, drug reactions, and foreign protein injection.

Qualitative Disorders of White Blood Cells

Qualitative disorders involve changes in the form or function of white blood cells.
Pelger-Huet anomaly is an inherited genetic mutation (sometimes acquired) causing abnormal neutrophil shapes (bilobed, peanut, or dumbbell).
Chediak-Higashi syndrome (genetic disorder) presents with abnormal large irregular granules, impaired lysosomal digestion of bacteria, and association with pigment disorders and blood disorders.
These abnormalities are usually associated with an increased risk of infection.

Chronic Granulomatous Disease (CGD)

In Chronic granulomatous disease (CGD), abnormal neutrophils phagocytose microorganisms but cannot kill them due to a lack of respiratory burst and peroxidase production.

Leukocyte Adhesion Deficiency (LAD)

Leukocyte adhesion deficiency (LAD) is an autosomal recessive disorder impacting leukocyte cell-surface adhesion proteins (integrins), specifically the CD11/CD18 complex.
Defective adhesion to endothelial cells, chemotaxis, C3bi-mediated phagocytosis, particle-triggered respiratory burst activation, and degranulation are characteristic of this condition.
Common clinical features include frequent bacterial and fungal infections, lack of pus formation, and delayed umbilical cord separation, along with persistent leukocytosis. Diagnosis involves flow cytometry analysis of neutrophil CD11/CD18 levels.

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Description

Explore the vital roles of white blood cells in the immune system and the process of hematopoiesis. This quiz covers the development, functions, and mechanisms of action of WBCs, as well as their formation from stem cells. Test your knowledge of how these cells protect the body from infections.