Exchange transfusion the hard way: massive hemolysis following transplantation of bone marrow with minor ABO incompatibility

BACKGROUND: Bone marrow transplantation using donors with minor ABO incompatibility may result in the rapid production of donor-derived red cell isohemagglutinins, causing hemolysis of recipient red cells. CASE REPORT: The transplant of sibling-donor marrow with minor ABO incompatibility (group O donor marrow to group A recipient), using FK- 506 as an immunosuppressant to prevent graft-versus-host disease, is reported. Following early myeloid engraftment, the recipient developed hemolysis of her entire A red cell population between Day 8 and Day 11. This brisk hemolytic anemia was due to rapid donor lymphoid engraftment that resulted in the explosive production of donor-derived anti-A. CONCLUSION: Patients undergoing the transplantation of marrow from donors with minor ABO incompatibility in which the donor cells can produce isohemagglutinins against the recipient's red cells must be kept under vigilant observation for the possible development of severe hemolysis, particularly in the setting of profound T-cell suppression without B-cell suppression.     

Model of Epstein-Barr virus infection of human thymocytes: expression of viral genome and impact on cellular receptor expression in the T- lymphoblastic cell line, HPB-ALL

Infection of B lymphocytes and epithelial tissue by Epstein-Barr virus (EBV) is associated with malignancy and autoimmunity. The cellular receptor for EBV has been identified as CD21 (CR2). A molecule, which is biochemically and immunologically similar to B-cell CD21, has been identified on a subpopulation of immature thymocytes, suggesting a role for this molecule in the regulation of T-cell development and further suggesting that immature T cells might be susceptible to EBV infection. A growing body of literature now documents the presence of EBV in tumors of T-cell origin. We have evaluated the susceptibility of the human immature T cell line, HPB-ALL, to infection by EBV. Electron microscopy studies showed a rapid internalization of virus by HPB cells. Southern blotting showed the intracellular presence of linear EBV genomes, and components of the virus replicative cycle were identified. Expression of the BamHI Z region of the genome, encoding the nuclear protein, ZEBRA, which is strictly associated with productive infection in B cells, was detected in HPB-ALL cells. A spliced variant of Z, RAZ, was also identified. Cell surface expression of EBV late antigens was observed to occur transiently. Infection of HPB cells was also accompanied by altered expression of T-cell surface molecules involved in antigen recognition, a process critical to normal development of the T-cell repertoire. Delineation of the outcome of T- cell infection by EBV may lead to a better understanding of the role of this virus in autoimmune processes and malignancy.     

Effects of agents that inhibit cellular iron incorporation on bladder cancer cell proliferation

Agents that interfere with cellular iron (Fe) incorporation inhibit tumor cell proliferation, including metals that bind to transferrin (Tf) such as gallium (Ga) or indium (In) and Fe chelators such as desferrioxamine (DFO). Ga nitrate is effective in the treatment of metastatic bladder cancer and these patients exhibit evidence for interference with Fe metabolism. We show here that bladder cancer cell proliferation in vitro is dependent on Tf-Fe. Concentrations of DFO that can be readily achieved in vivo inhibit cellular proliferation even in the presence of physiologic concentrations of Tf-Fe. Inhibition of proliferation by Tf-Ga is associated with decreased cellular Fe incorporation. However, when a physiologic concentration of Tf-Fe is added to an equimolar concentration of Tf-Ga, significant Fe incorporation is evident despite inhibition of proliferation. Thus, besides interference with Fe incorporation, Ga may also interfere with intracellular Fe distribution and/or directly inhibit an Fe- (or non-Fe- ) requiring process necessary for cellular proliferation. DFO followed sequentially by Tf-Ga results in marked potentiation of inhibition of proliferation. The effects of this combination appear to be related to both interference with Fe metabolism and increased Ga uptake. This sequential combination may be useful in the treatment of bladder cancer.     

Calcification in untreated mediastinal lymphoma

Calcification was demonstrated radiographically within newly diagnosed lymphoma of the mediastinum in two patients. These patients and those in other isolated reports show that radiographic examinations may, rarely, reveal calcification in lymphomatous tissue prior to treatment.