Comparison of Two Different Doses of Rabbit ATG-Fresenius With Cyclosporin in the Treatment of Acquired Aplastic Anaemia

Inclusion Criteria: i. Severe aplastic anemia characterized by: Bone marrow cellularity \<30% (excluding lymphocytes) AND At least two of the following: a. Absolute neutrophil count \< 500/ uL b. Platelet count \< 20,000/ uL c. Absolute reticulocyte count \<60,000/ uL i. Age \> 2 years old ii. Weight \> 9 kg Exclusion Criteria: i. Diagnosis of Fanconi's anemia ii. Evidence of a clonal disorder on cytogenetics. Patients with very severe neutropenia (ANC \< 200 /uL) will be excluded iii. Failure of BMT iv. Prior immunosuppressive therapy with ATG, ALG, alemtuzumab, or high dose cyclophosphamide v. Infection not adequately responding to appropriate therapy vi. Serologic evidence of HIV infection vii. Failure to discontinue the herbal supplements or Other alternative approach of treatment within 2 weeks of enrolment viii. Moribund status or concurrent hepatic, renal, cardiac, neurologic, pulmonary, infectious, or metabolic disease of such severity that it would preclude the patient's ability to tolerate protocol therapy, or that death within 7-10 days is likely ix. History of carcinoma that is not considered cured (except local cervical, basal cell, or squamous cell) x. Current pregnancy, or unwillingness to take oral contraceptives or refrain from pregnancy if of childbearing potential xi. Not able to understand the investigational nature of the study or give informed consent