Downloaded from http://journals.tums.ac.ir/ on Wednesday, July 18, 2012 IJHOBMT vol.1, No.1; 2004 / 32 Unrelated Cord Blood Transplantation in Severe Combined Immuno- deficiency (SCID) Patients, the First Report in Iran Ghavamzadeh A, Moosavi A, Hedayatiasl A ,Alimoghadam K, Bahar B, Moghimi M, Eghbal L, Tavakoli M Hematology-Oncology and Bone Marrow Transplantation Research Center, Tehran University of Medical Sciences Severe combined immunodeficiency is a true pediatric emergency; children with SCID were the first patients with immunodeficiencies to be successfully transplanted with unrelated and T-cell-depleted, haploidentical bone marrow. The pattern of inheritance of SCID is X-linked and autosomal recessive (ADA def, Jak3, RAG1, RAG2, IL 7Rα). In this case report, we describe a one-year-old boy with B+T- SCID who received unrelated cord blood transplantation from the Cord Blood Bank in Germany with a 4/6 HLA antigen match. The conditioning regimen was 1mg/kg/day Busulfan and 10mg/kg/day Cyclophosphamide. Both of them were given for two days. GVHD prophylaxis was performed with Cyclosporine A and Methotroxate. Stage III skin GVHD appeared on day 7 and gastric GVHD with a 250-300 cc volume appeared on day 8. On day 14, CVP, CRP, LDH and SGOT increased, blood pressure decreased and arrhythmia with T change, AV block, RBBB and bradycardia appeared. With the conclusion of Myocarditis, the patient was treated with diuretics and limitation of liquid intake, Dexamethazone, Dopamine and IVIG. The heart condition was improved gradually. During hospitalization, there was no decrease in platelet count and radiated PRBCS transfusion was performed twice. The patient was discharged on day 60. Donor cell chimerism of 60% was detected with STR-PCR, which was followed up regularly and tapered the immunosuppressive therapy. Unrelated cord blood is a stem cell source in SCID patients and it is a curative treatment in patients without appropriate donors. Key words: SCID, cord blood transplantation Introduction: The syndromes of SCID are caused by diverse genetic mutation that lead to absence of all adaptive immune function and in many cases a lack of NK cells. Patients with this group of disorders have the most severe of all of the recognized immunodeficiencies. Affected infants diarrhea, pneumonia, otitis, sepsis and cutaneous infections within the first few months of life. Growth may appear normal initially but extreme wasting usually, ensues after diarrhea and infections begin. Persistent infection with opportunistic organisms such as candida albicans, pneumocystis carini, varicella, measles, parainfluenza 3, CMV, ebstein barr virus (EBV) and bacillus calmette– guerin (BCG) lead to death. Affected infants also lack the ability to reject foreign tissue and are therefore at risk for GVHD from maternal immunocompetent T cells crossing the placenta or from T lymphocyte in nonirradiated blood products or allogeneic bone marrow. Infants with SCID have lymphopenia. This is present at birth, indicating that the condition could be diagnosed in all affected infants if routine white blood counts and manual differential counts were done on all cord bloods. They also have an absence of lymphocyte proliferative responses to mitogens, antigens, and allogeneic cells in vitro, and delayed cutaneus anergy. Patients with ADA deficiency have the lowest absolute lymphocyte counts, usually less than 500/mm³. Serum immunoglobulin concentration is diminished to absent and no antibody formation occurs after immunization. Analysis of lymphocyte population and subpopulations demonstrate distinctive phenotypes for the various genetic forms of SCID. T cells are extremely low or absent in all types; when present, they are in most cases transplacentally derived maternal T cells. Typically, patients with SCID have a very small thymus (<1g) that usually fails to descend from the neck, contain few thymocytes, and lacks corticome- dullary distinction and Hassall corpuscles. The thymic epithelium appears histologically normal. Both the follicular and paracortical areas of the spleen are depleted of lymphocytes; lymph nodes, tonsils, adenoids and Peyer's patches are absent or extremely underdeveloped. Unless immunologic reconstitution is achieved through bone marrow transplantation, death usually occurs in the 1st year of life and almost invariably before the end of the 2nd year. If diagnosed at birth or within the first three months life, 95% of cases can be treated successfully with HLA-identical or T-cell depleted haploidentical bone marrow stem cells without the need for pretransplant chemoablation or post–transplant GVHD prophylaxis. Patient introduction: Clinical Characteristics: A one-year-old boy, a known case of B+T-SCID who was referred to the Children's Medical Center of Tehran university of Medical Sciences. He was the second child of his family. The first child of the family died from diffuse infection after BCG vaccinination. The diagnosis was confirmed by family history, flow-cytometry and the considera- tion of immunoglobulin levels when he was two