ABSTRACT
A 11-month-old male with severe combined immune deficiency (SCID) received allogeneic bone marrow transplantation (BMT). He had suffered from recurrent infection and chronic diarrhea. Two older brother died of pneumonia 2 months after birth, but his HLA identical sister was healthy. He had very low number of T lymphocyte and NK cell. Although number of B lymphocyte was normal, level of immunoglobulin was extremely low. First BMT was done when he was 11 months old. Eighteen milliliter of bone marrow was simply infused without conditioning or GVHD prophylaxis. T lymphocyte appeared and fever which persisted despite use of antibiotics disappeared at day 7. Grade II GVHD developed, but was well controlled with corticosteroid. T lymphocyte subpopulation became normal at day 42. But pancytopenia developed and persisted despite use of G-CSF. Second BMT was done 4 months after 1st BMT. The conditioning regimen included busulfan (8 mg/kg) and cyclophosphamide (200 mg/kg), and ATG, cyclosporine and short-course MTX were used for GVHD prophylaxis. He achieved ANC> 500/uL at day 20 and platelet> 20,000/uL at day 29. BM examination on day 45 showed that 100% of marrow cells were donor origin. Acute and chronic GVHD did not develop. Since T lymphocyte was observed on day 21, various immunological parameters were normalized sooner or later. Immunological reconstitution was complete on day 280. Vaccination was given after 1 year of BMT and he is healthy now.