Successful nonmyeloablative bone marrow transplantation for leukocyte adhesion deficiency type I from an unrelated donor.

Leukocyte adhesion deficiency type I (LAD-I) is an inherited immunodeficiency disorder caused by defective expression of the leukocyte integrins, namely, lymphocyte function-associated antigen 1, Mac-1, and p150, 95, and is associated with obstructed cell adhesion, migration, and phagocytosis. Patients suffer from various bacterial or fungal infections and their prognoses are poor. The only curative treatment is hematopoietic stem cell transplantation. Conventional myeloablative transplantations have been performed, but with unsatisfactory results. We performed the first successful nonmyeloablative unrelated marrow transplantation for a 20-year-old female LAD-I patient, who suffered from recurrent and occasionally life-threatening infections such as cellulitis, gingivostomatitis, and sepsis. We adopted a preparative regimen with fludarabine, cyclophosphamide, and low-dose total-body irradiation, and tacrolimus and short-term methotrexate as immunosuppressants. This procedure was sufficiently immunosuppressive to obtain stable engraftment without remarkable complications, and graft-versus-host disease was controllable. Dramatic improvement of her disease was observed, supported by the normal expressions of integrins. Twenty one months after transplantation, she is well with a Karnofsky score of 100. Thus, nonmyeloablative transplantation is considered a feasible method for LAD-I.