Haem: Myelodysplastic syndromes and Aplastic anaemia Pt.2 Flashcards
List some inherited causes of aplastic anaemia.
RARE
- Fanconi anaemia
- Schwachman-Diamond syndrome
- Dyskeratosis Congenita
Outline the possible pathophysiology of idiopathic aplastic anaemia.
Characterised by failure of the bone marrow to produce blood cells
- Either due to an inherent issue with the stem cells or due to autoimmune attack on stem cells - spontaneous of molecular mimicry perhaps triggered by viral infection
What are the symptoms of aplastic anaemia?
- Anaemic symptoms - fatigue, SoB
- Leukopaenic symtpoms - infections
- Thrombocytopenic symptoms - easy bruising, bleeding
How is aplastic anaemia diagnosed and what would you see?
- FBC - cytopaenia
- Bone marrow biopsy - hypocellularity
How can aplastic anaemia be classified?
Severe (SAA) or non-severe (NSAA)
List some differential diagnosis for pancytopaenia and hypocellular marrow.
- Hypoplastic MDS/AML
- Hypocellular ALL
- Hairy cell leukaemia
- Atypical mycobacterial infection
- Anorexia nervosa (fatty replacement of bone marrow)
- ITP (although Hb and RBC will be normal)
What is the Camitta criteria for severe aplastic anaemia?
1) 2 out of 3 peripheral blood features:
- Reticulocytes < 1% (<20 x 10^9/L)
- Neutrophils < 0.5 x 109/L
- Platelets < 20 x 109/L
2) Bone marrow cellularity < 25%
Outline the management approaches used for bone marrow failure.
- Seek and remove cause
- Supportive (blood products, antibiotics, iron chelation)
- Immunosuppressive therapy (anti-thymocyte globulin, steroids, ciclosporin A)
- Drugs that promote bone marrow recovery (oxymetholone, eltrombopag)
- Stem cell transplantation
- Other treatments for refractory cases - alemtuzumab (T cell depletion), high-dose cyclophosphamide
Such a rare disease, sent to specialist centre with individualised therpy
How might the age of the patient influence decisions regarding their management?
- Immunosuppressive and androgens therapies tend to be used in older patients
- Stem Cell Transplant tends to be used in younger patients (80% cure rate)
List some late complications that occur after immunosuppressive therapy for aplastic anaemia.
- Relapse (35% in 15 years)
- Clonal haematological disorders - 20% risk in 10 years (myelodysplasia, leukaemia, paroxysmal nocturnal haemoglobinuria)
- Solid tumours (3% risk)
What is the most common cause of inherited aplastic anaemia?
Fanconi anaemia
What is the inheritance pattern of Fanconi anaemia?
Autosomal Recessive or X-linked Recessive
What do the gene mutations implicated in Fanconi anaemia tend to result in?
- Abnormalities in DNA repair
- Chromosomal fragility (breakage in the presence of in vitro mitomycin and diepoxybutane)
List some somatic abnormalities that are seen in Fanconi anaemia.
- Short stature
- Hypopigmented spots/café-au-lait spots
- Abnormality of thumbs
- Microcephaly or hydrocephaly
- Hypogonadism
- Developmental delay
(somatic abnormalities - those which you can see)
NOTE: these are only present in 70% of patients
List some complications of Fanconi anaemia.
- Aplastic anaemia (90%) - median age 9
- Myelodysplasia
- Leukaemia
- Cancer (epithelial)
- Liver disease