Clinical Laboratory Tests
HEMATOLOGICAL TEST
Test Notes
- No. of RBCs in mm3 blood
1- RBCs Count
- Indirect estimate of blood’s Hb
- % of packed RBC in whole blood after - Anemia
2- Hct or PCV
centrifugation - Over hydration - Dehydration
Packed Cell Volume
- 3x Hb - % or fraction of 1 - Blood loss
- Grams of Hb in 100 ml (1 dl) or 1 L
- Estimates O2 carrying capacity
3- Hb - Anemia
- Depend on No. of RBCs & amount of Hb
in each RBC
Variation in RBC shape (poikilocytosis)
- RBCs size, Hb conc. & Hb weight
4- RBC Indices sickle-cell anemia
- Used to categorize anemias
(Wintrobe) Variation in RBC size (anisocytosis)
- Peripheral blood smear
mixed anemia
- Ratio between Hct & RBC count - Macrocytic
5- MCV - Microcytic
- MCV = Hct (%) X 10 Vit B12 def.
(Mean Cell Volume) Iron deficiency
RBC count (In millions) Folic acid def.
- Amount of Hb in average RBC
6- MCH
- MCH = Hb X 10
(Mean Cell Hb)
RBC count (In millions)
- Average conc. of Hb in average RBC
7- MCHC - Hypochromia
- MCHC = Hb (g/100ml) X 100
(Mean Cell Hb Conc.) Iron deficiency
Hct
- Hemolytic anemia
- Measure of immature RBCs containing
- Acute blood loss
remnants of nuclear material (Reticulum)
- Drug-induced aplastic - Response to the
8- Reticulocyte count - They circulate in blood for 1-2 days
anemia treatment of a factor def.
- Index of bone marrow production of
(Fe,B12,folate)
mature RBCs
- Polychromasia
- Rate of RBCs settling of whole
- Infection (Acute or Chronic)
uncoagulated blood over time
- Tissue necrosis or
- Used to
9- ESR infarction
1- Follow the clinical course of a disease
(Erythrocyte - Malignancy
2- Presence of occult organic disease
Sedimentation Rate) - Rheumatoid collagen
3- Differentiate conditions with similar
diseases
symptomatology
- Myocardial infarction
Angina: No change, Myocardial infarction:
Leucopenia
- Bone marrow Leucocytosis
depression - Infection (Bacterial)
1- WBCs Count - No. of WBCs in mm3 blood
- Metastatic carcinoma - Leukemia
- Lymphoma - Tissue necrosis
- Antineoplastic agents
Neutropenia Neutrophilic Leucocytosis
With in immature cells
- Overwhelming
- Systemic infectn : pneumonia
infection (Bone - Viruses: Chicken pox, herpes
marrow is unable to zoster
keep up with the - Rickettsial diseases: Rocky
demand) Mountain spotted fever
- Mature : Polymorphnuclear leukocytes - Fungi
- Viral Infectn: mumps,
PMNs “polys” or Segmented “segs” - Stress: Physical, hemorrhage,
measles
- Immature : “bands” or “stabs” emotional
2- Neutrophils - Idiocyncratic drug - Inflammatory dis. : rheumatic
- Chemotaxis : Body’s 1st line of defence
reactions fever, rheumatoid arth. , gout
Congregate at sites in response to stimulus
- Chemotherapy - Hypersensitivity to drugs
ANC - Tissue necrosis: burns,
= %Neutrophils X Total WBCs myocardial infarction , cancers
- Metabolic dis: Uremia,
Absolute Neutrophil
diabetic ketoacidosis
Count - Myelogenous leukemia
Neutropenia is - Certain drugs: epinephrine,
ANC > 1000 cells/mm3 lithium
- Blue with basic dye Basophilia
- Not apparent bec. of
3- Basophils - Function in circulation not understood - CML (Chronic Myelogenus
their small no.
- In tissues they’re referred to as mast cells Leukemia)
Eosinophilia
- Allergic reactions: asthma,
- Red with acidic dye
4- Eosinophils hay fever, drug allergy)
- Associated with immune reactions
- Parasitic infestation:
trichinosis, amebiasis)
- Immunologic activity: produce antibodies
B lymphocytes T lymphocytes Lymphocytopenia
T4 T8 - Debilitating illness Lymphocytosis
5- Lymphocytes Helper-inducer Suppressor cells - Immunodeficiency - Viral infection
- Atypical lymphocytes : associated with - AIDS
infectious mononucleosis
Monocytosis
- TB
6- Monocytes - Phagocytic cells - Subacute bacterial
endocarditis
- Recovery phase of infectn
Thrombocytopenia
Moderate < 100,000/mm3
- Smallest blood element Severe < 50,000/mm3
Platelets - Involved in blood clotting - Idiopathic
(Thrombocytes) - Vital to formation of hemostatic plug thrombocytopenic
after vascular injury purpura
- Drugs: quinidine,
sulphonamides
