Lab assessment of immune Function Flashcards
C3 convertase
Common step in all three complement pathways.
OIL
Opsonizaton
Inflammation
Lysis
Classical Pathway
IgM or IgG antibodies binding to antigens.
Lectin Pathway
Antibody is replaced by Lectin such as BMP
Alternative Pathway
Does not require presence of lectins or antibodies.
Why Measure Complement?
- In cases of recurrent infxn with normal WBC’s and no immunosuppression.
- Autoimmune antibody mediated syndromes
- DIagnose immune complex mediated syndromes (lupus, sjogrens, glumerulonephritis)
Lab Eval of complement (2)
CH50: Detects deficiencies in classical pathway
AH50: Detects deficiencies in alternative pathway
C3 and C4
Used to determine whether deficiencies or abnormalities in the complement system are causing, or contributing to, a pt’s disease.
Neutrophils
- AKA: segs, PMN’s, polys
- Primary defense against bacterial infxn
- Most are generally mature.
Bands
Less mature neutrophils
Those that have been released recently from the marrow into the blood.
Nucleus is not segmented, but has a band or rod-like shape
Left shift
- Often used when determining if a patient has an inflammatory process such as acute appendicitis.
- Means that bands have increased, indicating an infxn.
Decreased neutrophils
Knows an neutropenia.
Viruses and some drugs can cause this.
ex: TCA’s, Hepatitis, flu, rubeola
Eosinophils
-Associated with antigen-antibody reactions.
Increase or decrease in Eosinophils
Increased: Allergic rxns, hypersensitivity, parasites
Decreased: Corticosteroids
Basophils
- Phagocytes that contain heparin, histamines and serotonin.
- Called mast cells in the tissue.
- Used to analyze allergic rxns
Increase or decrease Basophils
Increase: alteration in bone marrow function (leukemia), Hodgkins
Decreased: Corticosteroids, allergic rxns, acute infxn
Monocytes
- Largest cells in normal blood
- Act as phagocytes in inflammatory diseases
- body’s second line of defense
Monocytosis
- Increased mononcytes in blood
- TB, malaria, rocky mtn spotted fever, monocytic leukemia, ulcerative colitis.
Lymphocytes
- Primary components of immune system.
- Source of serum immunoglobulins
Lymphocyte increase, decrease
Increase: viral infxns and TB
Decrease: Puts pt at a high risk if infxn (viral).
Normal WBC count
4,500 - 11,000 cells/cm (squared)
Normal percentages
PMN: 45-75%, 70% average
Lymphocytes: 20-45% 30% average
All others: small percentages (normal)
Neutropenia
Neutrophil count <1,800 in adults.
-infxns, drugs, chemicals, ionizing rad, hematopoetic disorders, hypersplenism.
Lymphocytopenia
ALC < 1,500 in adults.
- Increased destruction, decreased production
- increased loss
- malignancy, AIDS