Lecture 12: Leukocyte Disorders Part 1 Flashcards
What is a bone marrow biopsy/aspiration?
Drilling a hole into bone to obtain cellular contents of bone marrow.
What are CIs of bone marrow biopsy?
Severe bleeding disorders (DIC, hemophilia)
Thrombocytopenia is a relative CI.
What can we test with a bone marrow biopsy?
Histology
Cytogenetic testing
Flow-cytometry
What are the indications of a bone marrow biopsy?
Abnormal CBC diff with normal smear.
Evaluate progress of treatment
FUO
Unexplained splenomegaly
Testing iron if all other tests are inconclusive
Where do we NOT perform a bone marrow biopsy?
Areas with signs of infection, injury, or excess overlying adipose tissue (NO FATTY AREAS)
What is the preferred site for a BM biopsy/aspiration?
Posterior iliac crest
Alt is anterior iliac crest
What is the preferred site for a BM aspiration only?
Tibia (under general anesthesia, used for infants <1yo)
Sternum (2nd and 3rd ICS, older than 12yo + morbid obese)
What is the main cause of acute lymphoblastic leukemia (ALL)?
Chromosomal translocation
What is ALL?
Malignant disorder that originates in a single lymphocyte, resulting from an abnormal expression of genes.
It is the cell immediately after the common lymphoid progenitor.
What 4 things does ALL result in?
Rapid cell proliferation/self-renewal
Reduction in normal cell proliferation
Block in cell differentiation
Increased resistance in cell apoptosis.
Essentially, it stays as an immature lymphoblast, making more of itself. Since it stays immature, it does not enter apotosis easily.
How does ALL impair hematopoiesis?
Accumulation of the lymphoblasts within the bone marrow suppresses the normal hematopoiesis since there is limited room.
Once it builds up, the bone marrow releases the lymphoblasts elsewhere to other organs.
How likely is ALL due to genetics vs environment?
Genetics are only 5% of cases.
95% are due to environmental factors.
What are the environmental factors associated with ALL?
In utero radiation exposure.
Chemicals
High birth weight (increase insulin-like growth factor 1)
LACK OF EXPOSURE to infections in the first few weeks of life.
Who is ALL MC in ?
Children, usually DXd prior to 15yo.
What gender is ALL MC in?
Males by a little.
What is the MC symptom in ALL?
FUO (fever of unknown origin)
What 3 hematologic conditions are common in ALL?
Neutropenia
Anemia
Thrombocytopenia
What is the main cause of all the S/S in ALL?
The direct infiltration of marrow or other organs by leukemic cells.
When do most deaths due to ALL occur?
In adults.
What are significant S/S of ALL?
LAN (often all lymph nodes, not specific)
Bone pain (a deep pain at night that wakes them)
Early satiety (splenomegaly bc stomach is compressed)
Mediastinal mass
Painless testicular swelling/mass
What is leukostasis?
Hyperleukocytosis, aka WBCs > 100k that causes neurologic symptoms.
Leads to inadequate circulation.
How emergent is leukostasis?
Very!
Risk of ICH, that lasts even 1 week after reduction.
40% mortality in 2 days if not treated.
How would someone with ALL potentially describe their symptoms?
Deep aching pains at night
Getting full very easily
Dysphagia, persistent chest pain
General swelling of lymph nodes
What would an initial workup of ALL be?
CBC
CMP
Blood cultures
CXR
CT/MRI Brain (WITHOUT contrast)
What would I expect on a CBC of an ALL patient?
Decreased RBC, platelets, and neutrophils.
WBC could be low, normal, or high.
Why do we order a CXR for an ALL patient?
R/o pneumonia
Check mediastinal mass
Why do we order a brain MRI/CT?
Neurologic s/s
Leukostasis suspected
Case Study:
Further history reveals the patient has multiple febrile illness recently but no specific cause was identified. Mother has noticed that he has been less energetic than usual. On exam, you note the child has lost 5 lbs since last visit 6 mo ago. He has cervical, axillary, and inguinal LAN throughout, measuring 1.5-2.0cm.
What do these symptoms suggest? What are the key symptoms?
Febrile illness without cause = FUO.
Less energetic = possible anemia.
Lost 5 lbs = loss of appetite, early satiety, UNintentional weight loss
Generalized LAN = concern for systemic infection.
When are blood cultures generally ordered?
Signs of infection.
What are additional lab tests we could order to work-up ALL?
Peripheral smears
LDH
CT Chest with Contrast
What would I typically see on a smear for an ALL pt?
Pancytopenia with circulating lymphoblasts.
Why does LDH elevate in ALL?
Tissue destruction.
When would I order an LP for ALL? What am I looking for?
All patients with suspected ALL to check for CNS involvement.
+ Lymphoblast cells in CSF.
What would show up in a flow-cytometry test for an ALL patient?
ALL cells will express CD19 antigens and potentially CD10 antigens.
Lack of mature T-cell markers as well. (CD3, CD4, or CD8)
What would show up in a bone marrow aspiration & biopsy for an ALL pt?
> 20% lymphoblasts per the WHO.
This is the definitive diagnostic method for ALL.
What are the two treatments for ALL patients?
Induction chemotherapy
CNS prophylaxis
What is the goal of induction chemotherapy?
Remission induction via MULTI-DRUG chemotherapy.
How is CNS prophylaxis administered?
Intrathecal therapy at all stages.
What is intrathecal therapy?
Direct administration of chemotherapy via administration directly into the EPIDURAL space.
What should we do if ALL is highly suspected?
Refer to heme onc.
What is the post-remission therapy in young ALL pts able to tolerate chemo?
Readministration of the induction regimen in order to increase the time of remission.
Either intensified therapy or maintenance therapy.
Maintenance lasts 2-3 years, much longer.
When can an ALL pt undergo intensified post-remission therapy?
They must have normal hematopoiesis.
Lasts 4-8 months.
What is the post-remission therapy for older ALL pts who cannot withstand chemo?
Allogeneic stem cell transplant.
AKA all patients that are matching donors.
How is an allogeneic stem cell transplant given?
Person undergoes massive, intensive chemo to irradiate all their bone marrow.
They are then transfused with the donor stem cells over an hour.
How do we manage leukostasis in ALL pts?
Prophylaxis for tumor lysis syndrome via IV hydration and hypouricemia agents.
Emergent chemo and leukapheresis if leukostasis present.
Why is tumor lysis syndrome so dangerous?
Spillage of tumor contents can cause massive electrolyte abnormalities.
What is leukapheresis?
Removal of whole blood to remove the WBCs.
The blood is then retransfused into the patient.
What is the cure rate of ALL in children vs adults?
90% in children.
50% in adults.
If a patient with ALL relapses, when is it most likely to occur?
Within first 2 years.
Reappearance of leukemic cells at any site.
Where is the MC site of relapse for an ALL pt?
CNS.
Hence why we do intrathecal chemo.
What falls under good prognostic criteria for ALL?
- No chromosomal abnormalities
- Younger than 39
- WBC < 30k
- Complete remission within 4 weeks.
Damage to what cell is the cause of Chronic Lymphocytic Leukemia? (CLL)
B cells
What is the etiology of CLL?
Malignant lymphoid neoplasm characterized by accumulation of long-lived, functionally incompetent, small mature B cells.
Results in dysfunction in the maturation of B cells.
What are the B cells of CLL unable to do?
They DO NOT RESPOND to immunologic stimulation.
What are the epidemiology stats of CLL?
MC form of leukemia in the US!!
MC in elderly, 90% occur after age 50.
MC in white males.
How does CLL commonly present?
LAN (MC finding)
Recurrent infections (Pneumonia, HSV, HZV)
HSM (early satiety)
S/S of anemia/thrombocytopenia in advanced CLL.
How does a CBC of CLL appear?
WBC > 20k
Isolated absolute lymphocytosis is the HALLMARK SIGN.
+/- decreased RBC, platelets
Bonus: What is normal WBC range?
5k-10k