Phase I study of high-stringency CD8 depletion of donor leukocyte infusions after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Donor leukocyte infusions (DLI) are given after hematopoietic stem-cell transplantation to eradicate persistent tumor or correct mixed chimerism (MC). The drawback of DLI is the risk of graft-versus-host disease (GVHD). In this phase I study, we examined the potential of highly extensive CD8 depletion of DLI as a means of improving its safety profile. METHODS: High-stringency immunomagnetic CD8 depletion of DLI was performed after steady state donor apheresis. Patients with persistent disease or MC received escalated dose CD8-depleted DLI at 3-month intervals starting from 6 months posttransplantation. The starting dose was 1 x 10(6) CD4 cells/kg in recipients of unrelated and 3 x 10(6) CD4 cells/kg in recipients of related donor transplantations. RESULTS: Twenty-eight patients received CD8-depleted DLI (n=16 unrelated or mismatched, n=12 human leukocyte antigen-identical sibling). Median CD8 depletion was more than 4 log. The median overall dose of CD4+ cells/kg given was 4 x 10(6) (range 1 x 10(6)-43 x 10(6)). Conversion from MC to full donor chimerism was observed in 8 of 16 evaluable patients, and disease responses occurred in 5 of 11 patients (complete response in four and partial response in one). Five of 28 patients developed severe acute pattern (grade II-IV) GVHD. Two patients died as a result of complications relating to GVHD. CONCLUSIONS: Graft-versus-tumor effects can be observed after high-stringency CD8-depleted DLI, although the major toxicity remains GVHD in this high-risk patient group. The safety and efficacy profile of this approach will require testing in a randomized controlled study.

Method for the determination of Aconitum alkaloids in dietary supplements and raw materials by reversed-phase liquid chromatography with ultraviolet detection and confirmation by tandem mass spectrometry: single-laboratory validation.

A study of single-laboratory validation (SLV) of a reversed-phase liquid chromatography (RP-LC) method was conducted for the determination of diester-diterpene Aconitum alkaloids, viz., aconitine, mesaconitine, and hypaconitine, in a variety of dietary supplements, including single- and multiple-ingredient dry powder extracts, pills, capsules, and raw materials. The Aconitum alkaloids in the samples were extracted by diethyl ether in the presence of ammonia. After cleanup with solid-phase extraction to remove the matrix interferences, the alkaloids were determined by RP-LC with UV detection at 235 nm, and the results were confirmed by tandem mass spectrometry. The linear responses for aconitine, mesaconitine, and hypaconitine based on the present LC system ranged from 0.5 to 200 microg/mL. Relative standard deviations of 2.0 to 6.9% were obtained from duplicate analysis of 6 test materials of different matrixes for the 3 Aconitum alkaloids performed by 2 analysts on 5 different days. The recoveries determined for supplements and raw materials spiked with 3 Aconitum alkaloids at levels of 2.5-10 microg/g were in the range of 86-99%. In view of the attainment of satisfactory results for accuracy, precision, and recovery in the SLV study, it is recommended that the method validation process proceed to a collaborative study.