Rh D blood group conversion using transcription activator-like effector nucleases.

Group O D-negative blood cells are universal donors in transfusion medicine and methods for converting other blood groups into this universal donor group have been researched. However, conversion of D-positive cells into D-negative is yet to be achieved, although conversion of group A or B cells into O cells has been reported. The Rh D blood group is determined by the RHD gene, which encodes a 12-transmembrane domain protein. Here we convert Rh D-positive erythroid progenitor cells into D-negative cells using RHD-targeting transcription activator-like effector nucleases (TALENs). After transfection of TALEN-encoding plasmids, RHD-knockout clones are obtained. Erythroid-lineage cells differentiated from these knockout erythroid progenitor cells do not agglutinate in the presence of anti-D reagents and do not express D antigen, as assessed using flow cytometry. Our programmable nuclease-induced blood group conversion opens new avenues for compatible donor cell generation in transfusion medicine.

Immune reconstitution after allogeneic hematopoietic stem cell transplantation in children: a single institution study of 59 patients.

PURPOSE: Lymphocyte subset recovery is an important factor that determines the success of hematopoietic stem cell transplantation (HSCT). Temporal differences in the recovery of lymphocyte subsets and the factors influencing this recovery are important variables that affect a patient's post-transplant immune reconstitution, and therefore require investigation. METHODS: The time taken to achieve lymphocyte subset recovery and the factors influencing this recovery were investigated in 59 children who had undergone HSCT at the Department of Pediatrics, The Catholic University of Korea Seoul St. Mary's Hospital, and who had an uneventful follow-up period of at least 1 year. Analyses were carried out at 3 and 12 months post-transplant. An additional study was performed 1 month post-transplant to evaluate natural killer (NK) cell recovery. The impact of pre- and post-transplant variables, including diagnosis of Epstein-Barr virus (EBV) DNAemia posttransplant, on lymphocyte recovery was evaluated. RESULTS: THE LYMPHOCYTE SUBSETS RECOVERED IN THE FOLLOWING ORDER: NK cells, cytotoxic T cells, B cells, and helper T cells. At 1 month post-transplant, acute graft-versus-host disease was found to contribute significantly to the delay of CD16(+)/56(+) cell recovery. Younger patients showed delayed recovery of both CD3(+)/CD8(+) and CD19(+) cells. EBV DNAemia had a deleterious impact on the recovery of both CD3(+) and CD3(+)/CD4(+) lymphocytes at 1 year post-transplant. CONCLUSION: In our pediatric allogeneic HSCT cohort, helper T cells were the last subset to recover. Younger age and EBV DNAemia had a negative impact on the post-transplant recovery of T cells and B cells.

Photodynamic therapy using verteporfin-induced minimal change nephrotic syndrome.

PURPOSE: To report a case of minimal change nephrotic syndrome (MCNS) after photodynamic therapy using verteporfin. DESIGN: Interventional case report. METHODS: After four cycles of photodynamic therapy, general weakness with generalized edema developed in an otherwise healthy 66-year-old woman, resulting in dyspnea and ascites. Urinalysis showed heavy proteinuria (4+) with decreased serum total protein and albumin, and increased total cholesterol levels, suggesting nephrotic syndrome. Renal biopsy and pathologic diagnosis were performed. RESULTS: Renal biopsy revealed normal glomeruli and tubulointerstitium by light microscopy, with no immunoglobin or complement deposition. Transmission electron microscopy showed diffuse effacement of the foot processes of visceral epithelial cells, which is the characteristic finding of minimal change nephrotic syndrome. CONCLUSIONS: We herein report a case of minimal change nephrotic syndrome after photodynamic therapy using verteporfin.