98 BM Failure Flashcards
Chapter 98 Bone Marrow Failure Syndromes
What are the bone marrow failure states?
Aplastic anemia
Myelodysplastic syndrome
Pure red cell aplasia
Myelophthisis
More frequent hematologic finding in bone marrow failure states
Pancytopenia
True or false. Hematopoietic failure syndromes are classed based on peripheral blood smear features.
False. Classified by dominant morphologic characteristic features of the bone marrow
Hypocellular bone marrow +/- pancytopenia
Q fever Legionnaires disease Anorexia nervosa starvation Mycobacterium
Pancytopenia with cellular bone marrow
Primary bone marrow diseases MDS PNH Myelofibfozjs BM lymphoms Hairy cell leukemia ================ Secondary systemic disease SLE Hypersplenism B12, Folate deficiency Alcohol HIV infection Sepsis
Pancytopenia with hypocellular bone marrow
Acquired Aplastic anemia
Rare a leukemic leukemia
Pancytopenia with marrow hypocellularity
Aplastic anemia
True or false. Aplastic anemia is related to PNH and MDS
True
Major cause of aplastic anemia
Idiopathic
Major acute sequela of radiation; radiation damages DNA
Marrow plasia
True or false. Aplastic anemia can be secondary to radiation, drugs and chemicals, viruses, and immune diseases
True
Chemical notorious in causing bone marrow failure
Benzene
Example of agents that produce marrow depression as major toxicity
Cytotoxic drugs
Agents associated with Aplastic anemia but with relatively low probability
Chloramphenicol Insecticides Antiprotozoals NSAIDs Anticonvulsant Heavy metals Sulfonamides Antihistamines Estrogen
Acquired mutation in what gene in hematopoietic stem cell is required for the development of PNH?
PIG-A
What is the clone progeny deficient in PIG A mutation?
Glycosylphospatodylinositol-linked cell surface membrane proteins
Autosomal recessive disorder that manifest as congenital developmental anomalies, progressive pancytopenia and increased risks of malignancy; short stature, cafe au lait spots, and anomalies involving the things, radius and GUT
Fanconi anemia
Most common generic defect in Fanconi Anemia
Mutation in FANCA
Most fanconi anemia gene products form protein complex that activates with what that play a role in cellular response to DNA damage esp interstrand cross linking
FANCD2
Characterized by triad of mucous membrane leukoplasia, dystrophic nails, reticular hyperpigmentation, and with development of aplastic anemia in childhood
Dyskeratosis congenita
Dyskeratosis congenital is due to mutation in what genes which acts to maintain telomere length in replicating
Mutations in DKC1 (dyskerin); genes of the telomere repair complex
Other autosomal mutation related to Dyskeratosis congenita due to mutation RNA template
TERC
Genetic mutations associated with Dyskeratosis congenita in the catalytic reverse transcriptase telomerase
TERT
Genetic mutation associated with Dyskeratosis congenita in genes that Encode shelterin proteins which bind telomere DNA
TNF2
Syndrome which presents early in life with neutropenia wth pancreatic insuffiency and Malabsorption with mutation in SBDS that affect ribosomal biogenesis
Shwachman-Diamond syndrome
Physical anomaly that gives clues to TERT and TERC mutations
Early hair graying
What is apparent in the morphology of the bone marrow biopsy specimen in Aplastic anemia?
Replacement of bone marrow with fat
Marker of early hematopoietic cells; it is increased or decreased in Aplastic anemia?
CD34 antigen is a marker of early hematopoietic cells and is diminished in Aplastic anemia
Responsible for Benzene induced tissue injury
Hydroquinone and quinolones
Most common early symptom of aplastic anemia
Bleeding
Unusual first symptom of aplastic anemia
Infection
What is the character of the bone marrow aspirate in Aplastic anemia
Readily aspirated but dilue on smear;may be grossly pale on withdrawal due to fats
What test is done on peripheral blood in children and young adults to exclude Fanconi anemia
Diepoxybutane
Mitomycin C
Shortened telomere suggest telomerase and shelterin mutation
How is Aplastic anemia diagnosed?
Straight forward: pancytopenia with fatty bone marrow
True or false. Aplastic anemia is disease of the elderly population
False. It is the leading diagnosis of pancytopenia in adolescent and young adult
What is the natural history of aplastic anemia?
Rapid deterioration and death
The major prognostic determination
Blood count
What is the criteria severe Aplastic anemia?
2 out of 3 1. Neutrophils count less than 500/uL 2. Platelet count less than 20K/uL 3. Reticulocyte count less than 1% OR Absolute Reticulocyte count less than 60K/uL
Better predictors of treatment response and long term outcome
Lymphocytes more than 1K/uL
Reticulocyte count more than 25K/uL
How can Aplastic anemia be cured?
Aplastic anemia can be cured by stem cell transplant
True or false. Glucocorticoids are the primary therapy in Aplastic anemia
False.
In preparation for stem cell transplantation, patient with Aplastic anemia should be given blood transfusion
Blood transfusion fro. Family members should be avoided to prevent sensitization to histocompatibility antigen
Induces hematolofic recovery in 60-70% of patient with Aplastic anemia
Antithymocyte Globulin + cyclosporine
What antithymocyte Globulin are available?
Horse ATG
Rabbit ATG: less effective
Characterized by cutaneous eruptions and arthalgia developing 10 days after initiating treatment
Serum sickness
Administered with ATG to ameliorate the immune consequences of heterologous protein infusion
Methylprenisolone
Important side effect of cyclosporine
Nephrotoxicity, hypertension and seizures
What is curative treament of aplastic anemia? What is the treatment of choice for Aplastic anemia?
Curative: stem cell transplant
Treatment of choice: immunosuppression
True or false. Survival is higher in patient receiving stem transplantation versus immunosuppresion
False. Survival between both is equivalent
True or false. Hematopoietic growth factors such as EPO and G CSF are effective in managing pancytopenia in Aplastic anemia
False. Endogenous blood levels of these factors are already high
Added to first line immunosuppresion therapy in Aplastic anemia
Eltrombopag
Up regulate telomerase gene activity and improve marrow function
Androgens
Should be added at the 50th transfusion to avoid secondary hemochromatosis
Deferoxamine and deferasirox
Single best method of preventing spread of infection in Aplastic anemia
Handwashing
Characterized by anemia, Reticulocytopenia and absent or rare erythroid precursors cells in the bone marrow
Pure red call aplasia
True or false. Pure red cell aplasia in adults is genetic
False. In adults, PRCA is acquired
What is the etiology of PRCA
Mutations in ribosome protein
True or false. PRCA has important associations with immune system diseases
True
What immune system disease is PRCA frequently a major manifestation
Large granular lymphocytosis
Complicate chronic lymphocytic leukemia
True or false. EPO has provoked PRCA mediated by neutralizing antibodies to hormone
True
More common immune mechanism in PRCA
T cell inhibition
Important curable cause of PRCA
Chronic parvo virus infection
Cytopathic sign of B19 parvo virus infection
Giant pronormoblasts
True or false. PRCA has poor long term survival
False. Long survival with supportive care of blood transfusion and iron chelation
What other drugs given to PRCA
Glucocorticoids Cyclosporine ATG Azathioprine Cyclosphosphamide
Two main characteristic of myelodysplasia
- Cytopenias due to bone marrow failure
2. High risk development of AML
5 subtypes of Myelodysplastic syndrome
- Refractory anemia
- Refractory anemia with sideroblasts
- Refractory anemia with excess blast
- Refractory anemia with excess blast in transformation
- Chronic myelomonocytic leukemia
Single somatic mutation a feature of Sideroblastic anemia
SF3B1
True or false. Myelodysplastic syndrome is a disease of the elderly. What is the mean age of onset.
True. Mean age of onset is 70 years old
True or false. MDS is associated with environmental exposures such as radiation and benzene
True
True or false. Therapy related MDS occur as early toxicity of cancer treatment
False. Late toxicity
Common chemothepeutic agents associated with MDS
Ankylating agents: busulfan, nitrosourea, procarbazine
DNA topoisomerase inhibitors
Pathophysiology of Myelodysplastic syndrome
Disordered cell proliferation and impaired differentiation
What cytopenia dominate the early course of Myelodysplastic syndrome?
Anemia
True or false. Patients with Myelodysplastic syndrome have splenomegaly.
True. About 20%
What is the bone marrow picture of MDS?
Bone marrow is usually normal or hypercellular in 20% of cases but not single characteristic feature of marrow morphology distinguishes MDS
Differential diagnoses of MDS
B12 or Folate deficiency should be excluded
Criterion set by WHO to differentiate between AML and MDS
AML has 20% blast in bone marrow
True or false. Most patients die as result of complications from pancytopenia rather than from leukemic transformation
True
What is the only cure of MDS
Hematopoietic stem cell transplantation offers cure of MDS
True or false. MDS is refractory to cytotoxic chemotherapy regimens
True
Hypomethylating agents for MDS
Azacitudine
Decitabine
Major toxicity of decitabine and azacitudine?
Myelosuppresion
Effective in reversing anemia in MDS, a derivate of thalidomide
Lenalidomide
What are the toxicities of lenalidomide?
Myelosuppresion
DVT and PE
Monoclonal antibody effective in young patients with MDS? Anti CD52
Alemtuzumab
Another name of secondary myelofibrosis
Myelophthisis
What are the three distinct features of myelophthisis
- Proliferation of fibroblasts in the marrow space (myelofibrosis)
- Extension of hematopoiesis into the long bones and into extramedullary sites usually spleen, liver and Lymph nodes (myeloid metaplasia)
- Ineffective erythropoiesis
Infection that precedes Aplastic anemia
Seronegative hepatitis
Causes transient Aplastic anemia
Parvo virus B19
Agents that regularly produce marrow depression as major toxicity in commonly used doses or normal exposure
Cytotoxic drugs: ankylating agents, antimetabolite, antimitotics, some antibiotics
Table 98-3
Agents that frequently but not inevitably produce marrow aplasia
Benzene
Agents associated wiht Aplastic anemia but with a relatively low probability
Chloramphenicol Antiprotozoals Anticonvulsant Heavy metals Sulfonamides Antihistamines A penicillamine Estrogen
Agents associated with Aplastic anemia is more tenuous
Streptomycin, tetracycline, methicillin, mebendazole Sedatives tranquilizers Allopurinol Methydopa Quinidine Lithium Guanidine Potassium perchlorate Thiocyanate Carbimazole