Selection of autologous CD4+ T-cells for adoptive T-cell substitution in patients with CD23+ B-cell CLL.

BACKGROUND: B-cell CLL (B-CLL) is accompanied by a progressive decrease in cellular immune functions, and treatment-related immunosuppression can further aggravate T-cell immunodeficiency. To reduce the risks of T-cell depletion, it seems feasible to collect autologous CD4+ cells at an early disease stage and subsequently reinfuse them during periods of profound T-cell depletion. METHOD: We describe a two-step cell-selection method to obtain highly enriched CD4+ T-cells from leukapheresis compounds of patients with CD23+ B-CLL. The double selection procedure was performed using the CellPro Ceperate device, and consisted of CD4+ selection followed by CD23 purging to further remove contaminating CD23+ B-cells from the CD4+ cell fraction. The results of eight runs performed with leukapheresis material obtained from eight patients with CD23+ B-CLL at different disease stages are presented. RESULTS: The CD4/CD23 double cell-selection procedure resulted in the purification of > 90% CD4+ cells. Median recovery of CD4+ T lymphocytes after selection was 46%, and was negatively affected by the initial tumor cell load. The final T-cell fraction still contained lymphocytes of the B-CLL clone, as determined by FACS and PCR. The cell-processing procedure had no impact on T-cell function, as assessed by the in vitro production of the cytokine interferon-gamma. Moreover, the selected CD4+ cells retained their capacity to co-stimulate mitogen-induced B-cell IgG production in vitro. CONCLUSION: The described CD4 selection/CD23 depletion strategy is a suitable approach to obtaining high numbers of functional active autologous CD4+ T cells for adoptive T-cell transfer in patients with CD23+ BCLL.

Cardio 7--portable system for high resolution ECG mapping.

One of the main difficulties in using body surface potential mapping (BSPM) techniques is the need of complicated multi-channel measuring system. In this paper practical portable ECG mapping system is introduced. The system consists of a notebook computer and a data acquisition system box connected to the computer by fast IEEE 1284 parallel interface working in ECP mode. Concept of the device enables to extend the basic 134-channel high-resolution multi-channel ECG amplifying unit up to 256 channels. Application software includes measurement and real time monitoring of ECG signals, computation and display of several types of body surface potential maps. System can be connected to hospital information networks and supply them with measured ECG data for advanced processing or central archiving.

Increased serum flt3-ligand in healthy donors undergoing granulocyte colony-stimulating factor-induced peripheral stem cell mobilization.

The effect of granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood progenitor cells (PBPC) on the endogenous serum levels of cytokines stem cell factor (SCF) and flt3-ligand (flt3-L) was studied in 18 healthy subjects undergoing allogeneic PBPC donation. Donors received a standardized mobilization regime consisting of a 4-day course of G-CSF, with leukapheresis on day 5. Endogenous serum flt3-L and SCF were determined prior to G-CSF administration, on the day of leukapheresis, and followed up until day +100 after cessation of G-CSF administration. The administration of G-CSF resulted in a transient elevation of endogenous flt3-L serum levels. At the day of leukapheresis serum flt3-L showed a median increase of 75% compared to serum flt3-L levels obtained before G-CSF treatment. The increase in serum flt3-L levels showed no correlation with the total number of progenitor cells mobilized. Cessation of G-CSF treatment led to normalization of serum flt3-L within 7 days post G-CSF administration. In contrast, serum CSF levels remained unchanged in response to G-CSF administration. Our results demonstrate a transient surge in serum flt3-L in relation to G-CSF-induced PBPC mobilization, although the assessment of endogenous flt3-L give no information regarding the ability for G-CSF-induced PBPC recruitment in healthy individuals.

Collection of peripheral blood stem cells (PBSC) after chemotherapy and administration of rhGM-CSF in children weighing less than 17 kg.

Peripheral blood stem cells (PBSC) were collected from six children weighing less than 17 kg. Stem cell pools had been expanded by chemotherapy and rhGM-CSF. Nineteen procedures were performed with a continuous-flow separator (CS 3000 plus) using central venous access. The extracorporeal line was primed with red blood cells and 5% albumin (HA). Acid-citrate-dextrose:- formulae A(ACD-A) was added in a median ratio 1:11 (range 1:9-1:15). A median number of 5.6 x 10(8) kg-1 NC (3.5-9.7) and 7.1 x 10(6) kg-1 CD34+ cells (2.1-26.1) were collected per patient. Four patients were transplanted with PBSC and showed normal haematopoietic recovery (leucocytes > 1000 microL-1 between days 11 and 12). The results show that successful PBSC collection and transplantation is possible even in small paediatric patients. Administration of growth factors results in a marked increase of peripheral white blood cells and in a higher yield of NC and CD34+ cells in PBSC collections.