I- Definition :
- insufficient quantity of hematopoiesis responsible pancytopenia.
- It may be acquired or congenital
II- Epidemiology :
- The AM is a rare disease
- L’incidence:< 10 cases / 1 million inhabitants / year
- 2 at 3 times more common in Asia than in Europe and America.
- Age: it can occur at any age, 02 peak frequency: < 20 years > 50 years.
III- pathophysiology :
Several mechanisms are implicated :
- Malfunction of the hematopoietic stem cell.
- A deficit of bone marrow microenvironment.
- Ineffective hematopoiesis related to immune dysregulation (autoimmunity).
IV- positive diagnosis :
A- Clinique :
1- Signs of inadequate blood :
- anemic syndrome : asthenia, pallor CM, headaches and dizziness
- infectious syndrome : fever, angina ulceronecrotique
- hemorrhagic syndrome : petechial purpura and easy bruising, gingivorragie, intraoral bubbles
2- No tumor syndrome
B- Additional tests :
- Hémogramme : Pancytopénie (normochromic normocytic anemia aregenerative, buffy neutropenia, thrombocytopenia)
- Blood smear : absence of abnormal cells
- Reticulocyte : low < 120 000/mm3
- myelogram : marrow cell diminished wealth, absence of abnormal cells (examination guidance)
- Marrow biopsy : it confirms the diagnosis:
This is hypocellularity marrow, replaced by a sheet of adipocytes and hemorrhagic edema of the support frame. She confirmed the absence of tumor infiltration or fibrosis.
V- Differential diagnosis :
Faced pancytopenia :
A- Central pancytopenia :
- medullary fibrosis.
- marrow involvement acute leukemia, lymphoma, myeloma, metastases of a primary tumor
- megaloblastic anemias (vitamin B12, folate)
- Hémoglobunurie paroxysmal nocturnal (HPN)
B- peripheral pancytopenia :
- Hypersplenism of PHTP
- immunological (collagen).
WE- Causes :
- Aplastic acquired (> 95% cases)
- Congenital aplasia medullary (rares)
A- Aplastic acquired :
1- secondary :
- toxic : ionizing radiation, benzene, insecticides, dyes, gangs
pharmaceuticals: antimitotic, sulfamides, chloramphenicol, sels d’or, colchicine, antithyroid drugs…
- Infections : viral hepatitis, spinal tuberculosis
- HPN : can reveal or complicate AM
2- idiopathic :
Diagnostic d’exclusion, this is the most frequent (70-80% cases)
B- Congenital aplasia medullary :
- Disease Fanconie : autosomal recessive hereditary disease, characterized by a T-DNA repair defect.
The full clinical signs associated aplastic anemia and malformations : abnormality inches, pigmentation, SGA cephalic, bone malformations, kidney, etc.
- Other : dyskeratosis congenita (Zinsser-Engman-cole) : dominated by dermatologic manifestations.
VII- Prognosis :
- Classification Camitta : prognostic and therapeutic interest, based on the data of the blood count :
– neutrophil < 500/mm3
– reticulocytes < 20000/mm3
– platelets < 20 000/mm3
* Severe bone marrow aplasia : 2 criteria or 3
* moderate myelosuppression : 0 or 1 criterion
* Severe bone marrow aplasia very : si fund< 200/mm3
VIII- Treatment :
- Keep the patient alive by symptomatic treatment in order to establish specific treatment
- Get a cure or prolonging survival
Symptomatic treatment :
- Hospitalization in a specialized
- Red blood cell transfusion
- Concentrated platelet transfusion
- Treatment of infection : Isolation and broad spectrum antibiotics.
specific treatment :
- androgens : Norethandrolone, Dntrol
- immunosuppressive: cyclosporin, anti lymphocyte serum.
- Cell transplants hematopoietic stem from an HLA-matched donor
- moderate myelosuppression: androgénothérapie.
- Severe bone marrow aplasia:
+ Topic < 40 years: HSC transplantation
+ Topic > 40 years: immunosuppressive: Ciclosporin AL + S
IX- Conclusion :
- The AMS prognosis was improved by the HSC transplantation that will cure 75 at 90 % patients. Immunosuppressive therapy achieves a response rate between 60 and 80% and survival 5 years 75%.
Dr BENHALILOU's course – Faculty of Constantine