Aplastic Anemia

Snapshot

A 15-year-old girl presents to the emergency room with a nosebleed that has not stopped for hours. She also has bleeding in her gums. She was recently started on carbamazepine for a newly diagnosed epileptic condition. Lab results reveal decreased counts in all leukocyte counts. Reticulocyte count is decreased as well. Carbamazepine is discontinued and a bone marrow biopsy is obtained.

Introduction

Pancytopenia caused by diminished, absent, or destructed hematopoietic stem cells
With bone marrow aplasia
Epidemiology
- no racial or gender predisposition
- most cases are idiopathic – it is believed to be an autoimmune etiology
Multiple different causes
- radiation
- drugs or chemicals
  - benzene
  - chloramphenicol
  - anti-epileptics (phenytoin and carbamazepine)
  - alcohol
  - alkylating agents
- insecticides
- viruses
  - EBV
  - HIV
  - CMV
  - HCV
  - parvovirus
    - can cause transient aplastic crisis
    - rarely can progress to aplastic anemia
- Fanconi anemia (congenital)
  - DNA repair defect
- idiopathic
- B12 and folate deficiency
- PNH
- SLE
- PTU and methimazole
Commonly seen in sickle cell patients who are infected with parvovirus B19

Presentation

Symptoms/physical exam
- insidious onset, but often initial symptoms are due to anemia or bleeding
- (often normocytic) anemia: fatigue, malaise, and pallor
- thrombocytopenia: mucosal bleeding and petechiae
leukopenia: infections

Evaluation

Differential Diagnosis

Treatment

Prognosis, Prevention, and Complications

Prognosis
- 10-year survival rate
  - immunosuppression – 68%
  - stem cell transplant – 73%
Complications
- infection
- bleeding
- complications of stem cell transplant
  - graft versus host disease