OBJECTIVES: I. Determine the safety of cyclosporine and mycophenolate mofetil as a non-ablative conditioning and post-transplantation immunosuppression regimen in patients with primary T-cell immunodeficiency disorders who undergo HLA-matched related or unrelated bone marrow transplantation to induce mixed hematopoietic chimerism (establishment of 1-95% donor CD3+ cells). II. Determine the kinetics of immune reconstitution of lymphoid cell subsets, T-cell function, and B-cell function after allogeneic bone marrow transplantation in this patient population.

PROTOCOL OUTLINE: Patients are stratified according to type of primary T-cell immunodeficiency disorder (severe combined immunodeficiency syndrome (SCID) vs non-SCID) and donor status (related vs unrelated). All patients receive cyclosporine orally or IV on days -1 through 50 and oral mycophenolate mofetil on days 0 through 27 in the absence of unacceptable toxicity. Unrelated donor recipients and non-SCID patients also undergo total body irradiation on day 0. All patients then undergo allogeneic bone marrow transplantation on day 0. Cyclosporine taper regimen begins on day 50 and continues through day 180 unless evidence of graft-versus-host disease.

Ages Eligible for Study:  up to  55 Years,  Genders Eligible for Study:  Both

Criteria

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

• Histologically proven primary T-cell immunodeficiency disorder
• Diminished immune responses based on primary defect in T-cell immunity (deficiency in T-cell number or function) including the following diagnostic categories: Severe combined immunodeficiency syndromes (SCID): SCID with presence of B lymphocytes X-linked SCID. Autosomal recessive SCID. SCID with absence of T and B lymphocytes. Purine metabolite deficiency. Adenosine deaminase (ADA) deficiency. Purine nucleoside phosphorylase (PNP) deficiency. Other T-cell immunodeficiencies: Bare lymphocyte syndrome (BLS). Omenn's syndrome. Hyper IgM syndrome. Wiskott-Aldrich syndrome. DiGeorge syndrome. Functional T cell defects. Defects in T cell receptor-CD3 complex. Interleukin-2 deficiency. Zap70 defect. Other T-cell functional defects defined by assays or clinical syndrome No viral-associated T-cell immunodeficiency disorder (e.g., HIV). Ineligible for conventional therapy HLA-matched bone marrow donor available HLA genotypically identical OR HLA phenotypically identical unrelated Matched serologically at HLA-A and B, and molecularly at HLA-C, DRB1, and DQB1 (mismatch at HLA-C allowed if matched molecularly at HLA-A and B).

--Prior/Concurrent Therapy--

• No concurrent growth factors with mycophenolate mofetil

--Patient Characteristics--

• Age: 55 and under
• Life expectancy: At least 30 days
• Other: No other disease or organ dysfunction that would limit survival to less than 30 days