aplastic

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5046

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 :

  1. Malfunction of the hematopoietic stem cell.
  2. A deficit of bone marrow microenvironment.
  3. 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 :

  1. medullary fibrosis.
  2. marrow involvement acute leukemia, lymphoma, myeloma, metastases of a primary tumor
  3. Myelodysplasies
  4. megaloblastic anemias (vitamin B12, folate)
  5. Hémoglobunurie paroxysmal nocturnal (HPN)

B- peripheral pancytopenia :

  1. Hypersplenism of PHTP
  2. 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 :

But :

  • 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

Indications :

  • 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