Clinical Interpretations of Lab Exams Flashcards
What does anicoytosis mean?
Poikilocytosis?
Anisocytosis = size
Poikilocytosis = morphology
What is the normal volume of RBC?
80-100 fL
Macro vs Microcytic?
Macro = >100 fL
Micro = <80 fL
How would you classify anemia?
Etiology vs MCV
Etiology –> Blood loss, Impaird Production, Increased Destruction
MCV -> Microcytic, Normocytic, Macrocytic
What blood test would you order to investigate an anemic patient?
CBC
CBC Components:
- PCV
- RBC Indices –> MCH and MCHC
- RDW
- TLC
- Diff
- PBS
PCV = Packed Cell Volume
MCH = Mean Corpuscular Hemoglobin
MCHC = Mean Corpuscular Hemoglobin Concentration
RDW = Red Cell Distribution Width
TLC = Total Leukocyte Count
Diff = Differential Leukocyte Count
PBS = Peripheral Blood Smear
What does mean corpuscular volume help with?
Determining macrocytic vs microcytic anemias
What is the normal range of WBC count?
4.0 to 11.0 K/uL
What is the normal range of RBC count?
4.40 to 6.00 M/uL
What is the normal range of Platelet count?
150 to 400 K/uL
What should the relative percentages of Neutrophils, Lymphocytes, Monocytes, Eosinophils, and Basophils be?
Neutrophils 50 to 70%
Lymphocytes 20 to 40%
Monocyte 2 to 12%
Basophil < 1%
Eosinophil < 5%
What is the normal range of Hemoglobin count?
Male –> 12 to 16 g/dL
Female –> 11 to 15 g/dL
***What is the normal range of MCV?***
80 to 100 fL
What is Reticulocyte Count (Retic Count) used for?
To assess erythropoietic activity
What is ESR used for?
A non-specific characteristic that tells you whether the disease is active or not
What is a Bone Marrow (BM) exam used for?
Used when cause of anemia is not evident
Reticulocyte Count
- Marker of
- Normal Range
- What to look for in Anemia
- Marker of effective erythropoiesis (bone marrow response to anemia)
- Normal range 0.5 to 1.5%
- % count is falsely elevated in anemia
***Must be corrected for degree of anemia***
Corrected Retic Count = (Patient Hct/45) x Retic Count
How are Reticulocytes detected in the blood?
Supravital stains - detect the thread-like RNA filaments in cytoplasm
Only remain in blood for 24 hours before becoming mature RBCs
Microcytic Anemia (MCV < 80 fL)
What are the four types? (List in order of how common they are)
- Iron Deficiency - Most Common
- Anemia of Chronic Disease (ACD) - e.g. Kidney/Renal Failure
- Thalassemia
- Sideroblastic Anemia - Least Common
What are some laboratory tests for microcytic anemias?
Serum Iron
TIBC (serum total iron binding capacity)
% Saturation [Serum Fe/TIBC] x 100
***Serum Ferritin –> Circulating fraction of storage iron (Single best test for iron studies)
Hb Electrophoresis (Gold standard for dx mild B-thalassemia; mild a-thalassemia is a dx of exclusion)
Hemolytic Anemias
- 3 Categories
- Drug-induced
- Autoimmune (Most Common; F > M)
***SLE most common cause of autoimmune hemolytic anemia (AIHA(
- 70% - Warm (IgG antibodies) type
- 30% - Cold (IgM antibodies + Complement) type
3. Alloimmune - Hemolytic Transfusion Reaction
- Hemolytic Disease of Newborn
Direct Coombs Test (DCT)
(i.e. Direct Antiglobulin Test (DAT))
Uses patient RBC (has already contacted/touched with antibody) (Cell, rather than protein)
- Patient’s RBCs are incubated with antihuman antibodies (Coombs reagent)
- RBCs agglutinate: antihuman antibodies form links between RBCs by binding to the human antibodies on the RBCs
Indirect Coombs Test (ICT)
(i.e. Indirect Antiglobulin Test (IAT))
Uses the patient’s serum or antibody directly (protein, rather than cell)
- Recipient’s serum is obtained, containing antibodies (Ig’s)
- Donor’s blood sample is added to the tube with serum
- Recipients Ig’s that target the donor’s RBCs form antibody-antigen complexes
- Anti-human Ig’s (Coombs Antibodies) are added to the solution
- Agglutination of RBCs occurs because human Ig’s are attached to the RBCs
When would you use Indirect Coombs Test vs. Direct?
To test mother’s who are Rh negative to see if baby is Rh positive
What does it mean if you see an increased percentage of Neutrophils?
Lymphocytes?
Increased Neutrophils –> Bacterial infection
Increased Lymphocytes –> Viral infection
Lymphoma
Lymphoid neoplasms arising in discrete masses
(e.g. in spleen or lymph nodes)
Leukemia
Lymphoid neoplasms with involvement of the blood and bone marrow
(usually no discrete masses)
Normal Lymph Node
Lymph Node - Germinal Center
(Larger cells are the macrophages)
What are used as tumor markers in lymphoma?
The various stages of lymphocyte differentiation
Lymphoma
- Tools for Diagnosis (4)
- Hematoxylin and Eosin (H&E Stain)
- Immunophenotyping (identifying cell type by protein expression)
***Critical - only way to determine if coming from B- or T-cell
- Immunohistochemistry
- Flow Cytometry
3. Cytogenetics/FISH (to identify chromosomal aberration)
4. Molecular Diagnostics (PCR detect monoclonal population - neoplastic lymphoid population)
What markers are looked for for B cells?
CD 19, 20, 21, 22
Occasionally light chain (lambda) globulin
What markers are looked for for T Cells?
CD 2, 3, 4, 8
What are the two methods used for immunophenotyping? (i.e. for determining if B- or T-cell origin)
Immunohistochemistry
and
Flow Cytometry
What are important factors to understand as far clinical presentation?
Age
Location
Multiple/single site of involvement
What does A or B mean about lymphoma stage?
What are the symptoms?
A = Asymptomatic
B = Sympatomatic
- PAINLESS, Non-tender mass/lymphadenopathy
- Fatigue
- Malaise
- Night Sweats (30% of patients)
- Fever
- Weight Loss
What is the pattern of atypical proliferation? (i.e. diffuse, nodular, or both)
Diffuse
What is the pattern of atypical proliferation? (i.e. diffuse, nodular, or both)
Nodular
What are some critical considerations of cellular morphology of a lymphoma to consider as a pathologist?
Do all cells look similar? monomorphic
Multiple cell types? polymorphic
Size
Nucleus (irregular, regular, round)
Chromatin (clumped, vesicular, open)
Cytoplasm (abundant/scant, color)
Mature (peripheral lymphoma) vs Immature (Lymphoblasts)
Monomorphic vs Polymorphic
Lymphoma: Main Categories
- Precursor B-Cell Neoplasms
- Peripheral B-Cell Neoplasms
- Precursor T-Cell Neoplasms
- Peripheral T-Cell and NK-Cell Neoplasms
- Hodgkin’s Lymphoma
- Precursor B-Cell Neoplasms - Immature B-Cells
- Peripheral B-Cell Neoplasms - Mature B-Cells
- Precursor T-Cell Neoplasms - Immature T-Cells
- Peripheral T-Cell and NK-Cell Neoplasms - Mature T-Cells and Natural Killer Cells
- Hodgkin’s Lymphoma - Reed-Sternberg Cells and Variants
What are the main predominating tumors in people under 10 years old compared to over 10 years old?
< 10 years old = Acute Leukemia
> 10 years old = Lymphoma
***Know this***
Staging of Lymphoma
- Stage I
- Stage II
- Stage III
- Stage IV
- All stages - A vs B
I - Single lymph node region or extralymphatic site (IE)
II - Two or more LN regions or EL sites (IIE) on same side of diaphragm
III - LN regions or EL sites (IIIE) on both sides of diaphragm
IV - Disseminated or diffuse involvement of one or more EL sites
For all stages:
A = Asymptomatic
B = Fever, night sweats, or > 10% weight loss
