Bone Marrow Transplant Flashcards
When host recogizes graft as foreign we get
rejection
When graft recognized host as foriegn this is
GVHD
T cells recognize:
histoINcompatability;
viruses, fungus, foreign substances
What must we do to a host so they don’t reject a graph?
Conditioning: ~7 day process
immune suppression to get rid of disease and host BM via chemotherapy
If you have lots of histoINcompatability you need______ conditioning during the conditioning phase
MORE
Why is prenatal screening so important?
We can find primary immune deficiencies right away and tx child before their immue system devos (don’t need conditioning)
Dr. Margolis referred to this as the ‘bane’ of a transplant doctors exsistance
Goals is working between GVH and GVL (graft vs leukemia) and we can’t separate those out yet
What type of cell is starting to be used more commonly instead of T cells in transplant?
NK cells
T cells cause GVHD
What type of cancer in a patient would BMT be an acceptable tx option in?
- Patients with cancers that start in the bone marrow (Leukemia).
- Patients with cancers that start elsewhere in the body (abdominal tumors, bone tumors).
What is the difference btwn autologous vs. allogeneic transplant
autologous = self allogeneic = non self or donor
What is the concept of an Auto Transplant?
its when you give pt back their own immune system or cells when they are going through chemotherapy so we can keep their chemo doses higher. (or if you have identical twin)
• Patients with bone marrow failure such as ______or hemoglobin abnormalities such as ______ and ______ can benefit from BMT
(aplastic anemia)
(thalassemia or sickle cell anemia).
- Patients with primary immune deficiency syndromes_____
* Patients with other inborn errors of metabolism like_____ benefit from BMT
SCID
Hurlers
– Allogeneic Donor like an HLA matched sibling will likely have different:
Minor Histocompatibility antigens
if mom is your BMT match how close of a match is she?
1/2 HLA match
Order of increasing histoINcompatability
Autologous/identical twin –> matched sib –> unrelated donor –> Half matched paren
Three sources of Hematopoietic Progenitor Cells
- Bone Marrow (Gold standard)
- Umbilical Cord Blood
- Peripheral Blood
Benefit of umbilical cord match?
– Lower risk of GVHD for same tissue match
Why is Peripheral blood donation less desirable?
Peripheral Blood
– Higher risk of GVHD for same tissue match
– The HPC cells may be manipulated to remove cells:
lower doses of chemotherapy and radiation, which are too low to eradicate all the bone marrow cells of a recipient. run lower risks of serious infections and transplant-related mortality while relying upon the graft versus tumor effect to resist the inherent increased risk of cancer relapse
Non-myeloablative conditioning
given immediately prior to a transplant is called the conditioning regimen, the purpose of which is to help eradicate the patient’s disease prior to the infusion of HSC and to suppress immune reactions. The bone marrow can be ablated (destroyed) with dose-levels that cause minimal injury to other tissues. increases GVHD
Myeloablative conditioning
Three steps of BMT
• Conditioning with chemotherapy+/- radiation
therapy.
– Different packages based on the variables ofdisease and donor.
– Myeloablative vs. Non myeloablative
• Infusion of the HPC product.
• Regrowth of the new marrow
After BMT we are susceptible to bacteria because:
neutrophils are low, as well anytime you have broken barriers due to mucositis and CVL – Gram Positive • Alpha Strep, Staph, Streps – Gram Negative • Hard to Kill Gram Negative Rods – Anaerobes • Clostridium Species
What are we more susceptible to fungal infection post BMT?
When neutrophils are low, as well as when
one is on steroids
Moulds: Inhaled and angioinvasive (Aspergillus,Mucor)
• Sinus, Chest, Disseminated in skin
– Yeasts: Leave the GI/GU tract and disseminate
• Candida species
How long are CD4 counts low post BMT and what does this make us concerned about?
Viral:
– Herpes Virus Family: Latency and reactivation
• HHV1,2; CMV; EBV; VZV; HHV6
– Community Acquired Virus follow community patterns:
• RSV, Influenza, Adenovirus, Enterovirus
Late effects of BMT:
Second cancers, relapse, infertility End-Organ Function – Heart – Lung – Kidneys – Liver – Brain and Neurocognitive Development
