Unit 2 - Mechanisms of
Self Defence: Immunity
and Infection
Group B
Tammy, 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 betahemolytic 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?
References
Borton, 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. nd
(2000). Pathophysiology: Biological and
behavioral perspectives. (2 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 from
http://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.