OBJECTIVETo evaluate cord blood stem cell transplantation (CBT) in the treatment of X-linked agammaglobulinemia, and observe the courses of the hematopoietic and immune reconstitution.

METHODSA 14-year-old male patient with agammaglobulinemia received CBT from a 1/6 HLA-mismatched unrelated cord blood. The conditioning regimen was Bu/Cy/anti-CD3 antibody. CsA was given together with MMF and MTX for prophylaxis of GVHD. The patient received 0.42 x 10(8) nucleated cells/kg, containing 0.35 x 10(6) CD34(+) cells/kg.

RESULTSThe recipient showed hematopoietic reconstitution on day 30 post-transplantation when ANC was 0.5 x 10(9)/L and BPC 20 x 10(9)/L. Sex chromosome analysis showed engraftment (donor 46, XX/recipient 46, XY = 4:1) on day 45. The recipient's blood group changed from AB to O, IgG from 1.1 g/L to 3.5 g/L, sex chromosome from 46, XY to full 46, XX, and mature B cells in peripheral blood from 0 to 5% on day 100, indicating immune reconstitution. At the last follow-up of 360 days, the patient without acute or chronic GVHD showed normal hemogram and myelogram, IgG 13.5 g/L and 10% mature B cells in peripheral blood, indicating the hematopoiesis and immune persistent reconstitution. No acute or chronic GVHD was developed.

CONCLUSIONThis is the first case report of successful treatment of X-linked agammaglobulinemia by HLA-mismatched unrelated CBT.