Synchronous development of acute myeloid leukemia in recipient and donor after allogeneic bone marrow transplantation: report of a case with comments on donor evaluation.

BACKGROUND: A case of donor cell leukemia (DCL) is reported. A 42-year-old female developed acute myeloid leukemia (AML) of donor cell origin 18 months after a bone marrow transplant (BMT) from her brother. At the time DCL presented, the donor-brother was also diagnosed with AML showing identical cytogenetic abnormalities. The classification of DCL and recommendations for laboratory testing of potential hematopoietic stem cell (HSC) donors are discussed. STUDY DESIGN AND METHODS: Marrow specimens were obtained from the posterior iliac crest and analyzed using standard techniques. Leukemic cells were analyzed by flow cytometry. Karyotyping and fluorescence in situ hybridization were performed using standard methods. RESULTS: The recipient-sister's original diagnosis was erythroleukemia. Chromosome analysis showed a 46,XX,t(3;5)(q25;q34) karyotype. Both the recipient's new AML and the donor's AML showed an identical karyotype: 46,XY,inv(3)(q21q26),-7. Both patients were resistant to therapy and died. CONCLUSION: The clinical and biological aspects of DCL are discussed including the distinction between transformation of healthy donor cells to leukemic cells and transmission of preformed leukemic cells. The former represents almost all the reported cases of DCL compared with transmission of leukemic cells from donor to recipient. With an aging donor population, it is estimated that the latter will increase. Increased testing of older donors to include routine morphologic study of blood and marrow, cytogenetic studies, and evaluation for clonal lymphoproliferative disorders is recommended.

Anti-CD3 x anti-epidermal growth factor receptor (EGFR) bispecific antibody redirects T-cell cytolytic activity to EGFR-positive cancers in vitro and in an animal model.

PURPOSE: Targeting epidermal growth factor receptor (EGFR) overexpressed by many epithelial-derived cancer cells with anti-EGFR monoclonal antibodies (mAb) inhibits their growth. A limited number of clinical responses in patients treated with the anti-EGFR mAb, (cetuximab), may reflect variability in EGFR type or signaling in neoplastic cells. This study combines EGFR-targeting with the non-MHC-restricted cytotoxicity of anti-CD3 activated T cells (ATC) to enhance receptor-directed cytotoxicity. EXPERIMENTAL DESIGN: ATC from normal and patient donors were expanded ex vivo. Specific cytolytic activity of ATC armed with anti-CD3 x anti-EGFR (EGFRBi) against EGFR-expressing cancer cells derived from lung, pancreas, colon, prostate, brain, skin, or EGFR-negative breast cancer cells was evaluated in (51)Cr release assays. In vivo studies comparing tumor growth delay induced by EGFRBi-armed ATCs or cetuximab were done in severe combined immunodeficient/Beige mice (SCID-Beige) bearing COLO 356/FG pancreatic and LS174T colorectal tumors. RESULTS: At effector/target ratios from 3.125 to 50, both EGFRBi-armed normal and patient ATC were significantly more cytotoxic, by 23% to 79%, against EGFR-positive cells over ATC, cetuximab, anti-CD3 alone, or ATC armed with irrelevant BiAb directed at CD20. EGFRBi-armed ATC also secreted significantly higher levels of some T(H1)/T(H2) cytokines compared with ATC alone. In mice, i.v. infusions of EGFRBi-armed ATC (0.001 mg equivalent/infusion) were equally effective as cetuximab (1 mg/infusion) alone for significantly delaying growth of established COLO 356/FG but not LS174T tumors compared with mice that received ATC alone or vehicle (P < 0.001). CONCLUSIONS: Combining EGFR antibody targeting with T cell-mediated cytotoxicity may overcome some limitations associated with EGFR-targeting when using cetuximab alone.

Lack of bleeding in patients with severe factor VII deficiency.

Factor VII deficiency, although rare, is now recognized as the most common autosomal recessive inherited factor deficiency. It is usually considered to be associated with bleeding only in the severely affected subject and heterozygotes (>10%) are not considered at risk. The general recommendation for surgery is to achieve a FVII level in excess of 15% (0.15 1U/mL). We present three cases of severe factor VII deficiency, each of whom appeared hemostatically competent based on clinical history. Subject 1 is a 33 year-old African-American female with a baseline FVII of <1%, who had a fractured tibia requiring open reduction with internal fixation without any FVII replacement and subsequently underwent successful laparoscopic knee surgery with a factor VII level measured at 6%. Subject 2 is a 58 year-old African-American female with a factor VII level of 9% who underwent an elective left total hip replacement without any factor replacement and had no excessive bleeding, but who sustained a pulmonary embolism postoperatively. Subject 3 is a 19-year-old African-American male with a baseline FVII of 1% with a history of active participation in football without noticeable injury and who underwent an emergent appendectomy without bleeding. These three cases represent individuals with the severe form of FVII deficiency who did not exhibit excessive bleeding when challenged with surgical procedures. The clinical history would appear the most valuable tool in predicting the likelihood of bleeding in these patients, and we suggest that the presumption that all patients with severe FVII deficiency should receive replacement therapy before surgical procedures may not be valid in all cases.