Unit 2 - Mechanisms of Self Defence: Immunity and Infection

Group BTammy, Heather and Merissa

Question

If the neutrophil count was high in a WBC differential, what kind of infection would you suspect? If the lymphocyte count was high?

Neutrophils

• neutrophils arrive to the site of inflammation or injury within 6 to 12 hours (McCance & Huether, 2006).

• Neutrophils have the ability to release chemical mediators to destroy microorganisms (Copstead & Banasik, 2000).

Band Cells

• Immature neutrophils are called bands or stabs

• An increase in these cells indicates that the bone marrow has depleted its store of mature neutrophils

• The term “a shift to the left” is used when band cells are elevated (Borton, 1996)

• An elevation of band cells may be reflective of an infectious process.

•

Lymphocytes • Lymphocytes are nonphagocytes

of the adaptive immune response and the two types are T lymphocytes and B lymphocytes(McCance & Huether, 2006).

• T and B lymphocytes have the ability to recognize foreign antigens found in the environment and each individual T or B lymphocyte recognizes one particular antigen (McCance & Huether, 2006).

• T lymphocytes are released from the thymus and B lymphocytes are released from the bone marrow (McCance & Huether, 2006).

What kind of infections increase neutrophils?

• you would suspect an early, acute stage of an infectious process

• neutrophil counts may also be elevated with non-infectious inflammatory states

• acute myocardial infarction • diabetic ketoacidosis • acute hemorrhage • corticosteroid use

What kind of infections increase neutrophils?

• Neutrophil would also be increased in:

• malignant tumors • kidney infections • hemolytic anemia • post operatively• Influenza

What kind of infections increase lymphocytes?

• Lymphocytes are increased during severe infection, cancer of the blood or lymphatic system and autoimmune disorders that cause chronic inflammation (Mayoclinic, 2009).

• acute infection – example mononucleosis

• chronic infection – example congenital syphilis

• malignant process such as Acute Lymphocytic Leukemia or Chronic Lymphocytic Leukemia (Mayoclinic.com).

What kind of infections increase lymphocytes?

• Increased lymphocytes are seen in patients with

• Tuberculosis• Mumps• rubella• crohn's disease• herpes simplex • Hepatitis• Lymphocytes can also rise after blood transfusions

(Carone, 2009)

Making Sense of it all in clinical situations

Case Study

Jason Hornbuckle is not a happy little boy. For the past 12 hours he has complained of pain when he swallows, has a headache, and has vomited twice. His mother decides to take the seven-year-old to his pediatrician. Upon examining Jason, the doctor finds that Jason’s pharynx, tonsils, and uvula are swollen and erythematous (red) and his tonsils are studded with white areas of exudate. He is febrile (temperature 40.3 degrees centigrade) with tender, bilateral, cervical lymphadenopathy (enlarged lymph nodes).

A Complete Blood Count (CBC) performed on a sample of Jason’s blood reveals that he has

a leukocytosis (increased number of WBCs) due to a neutrophila (increased number of neutrophils).

Jason is diagnosed as having acute bacterial pharyngitis and treated with phenoxymethyl

penicillin for five days. A throat swab taken before starting antibiotics grows beta-hemolytic streptococci (Group A). After three days of treatment, Jason’s temperature has returned to normal and he has made an uneventful recovery.

Dean (2009)

Question

1. The exudate on Jason’s tonsils consisted primarily of neutrophils, and the CBC that was performed indicated that the number of neutrophils in his circulation was increased. What role do neutrophils play in the resolution of a bacterial infection?

Dean (2009)

Discussion Question

Our group has discussed what increases neutrophils and lymphocytes but….

What diseases and infections decrease neutrophils and

lymphocytes?

ReferencesBorton, D. (1996). WBC count and differential. Nursing ’96, 26(9). 26-31.

Brashers, V. (2006). Innate Immunity. Elsevier Mobsy.

Britannica. (2009). Human lymphocyte. Retrieved January 10, 2009 from: www.britannica.com/.../6452/Human-lymphocyte

Carone, D. (2009). Medfriendly. retrieved January 9, 2009 from: www.medfriendly.com/lymphocyte.html

Copstead, L. C., & Banasik, J. (2000). Pathophysiology: Biological and behavioral perspectives. (2nd ed.). Philadelphia, PA: W.B. Saunders Company.

Dean, D. (2009). A case of Pharyngitis. Spring Hill College. Retrieved January 14, 2008 from: http://www.sciencecases.org/sore_throat/sore_throat.asp

References

Doctor NDTV (2007). Why is my neutrophil count high? Retrieved online January 8, 2009 from http://doctor.ndtv.com/faq/detailfaq.asp?id=11297

Google images. (2009). Retrieved January 10, 2009 from: faculty.une.edu/com/abell/histo/histolab3a.htm

Hicks, M. (2009). Clip Art Gallery. Retrieved January 12, 2009 from: school.discoveryeducation.com/clipart/clip/th...

Mayoclinic.com: Blood and lymphatic system. Retrieved online January 8, 2009

fromhttp://www.mayoclinic.com/health/lymphocytosis/MY00360/rss=1

McCanace, K., & Huether, S. (2006). Pathophysiology: The biologic basis for disease in adults and children. (5th ed.). St. Louis, MI: Elsevier Mosby.