Association of surgeon with surgical site infection after liver transplantation.

Surgical site infection (SSI) after liver transplantation has been associated with increased risk of allograft loss and death. Identification of modifiable risk factors for these infections is imperative. To our knowledge, intraoperative practices associated with transplant surgeons have not been assessed as a risk factor. A retrospective cohort study of risk factors for SSI after 1036 first liver transplantations completed by seven surgeons at a single center between 2003 and 2008 was undertaken. Cox proportional hazards models were used to evaluate the association between surgeons and SSIs. SSIs were identified in 166 of 1036 patients (16%). Single variable analysis showed strong evidence of an association between surgeon and SSI (p = 0.0007); the estimated cumulative incidence of SSI ranged from 7% to 24%. This result was consistent in multivariable analysis adjusting for potentially confounding variables (p = 0.002). The occurrence of organ-space or deep SSI varied significantly among surgeons in both single variable analysis (p = 0.005) and multivariable analysis (p = 0.006). These findings provide evidence that differences in the surgical practices of individual surgeons are associated with risk for SSI after liver transplantation. Identification of specific surgical practices associated with risk of SSI is warranted.

Multiple myeloma patients receiving large volume leukapheresis efficiently yield enough CD34+ cells to allow double transplants.

Current protocols for myeloma patients require more than one autologous transplant. We performed a retrospective study to determine the cost-effectiveness of large volume leukapheresis (LVL) compared with standard volume leukapheresis (SVL) collection when two transplants are required. We evaluated 87 patients who underwent a cumulative total of 260 LVL and SVL collections. The median product volume per collection was 356 ml for LVL, and this was significantly higher than the median product volume per collection for SVL (median 149.5 ml, P < 0.001). The median total CD34+ cell yield/kg was 6.4 x 10(6) for LVL and 5.2 x 10(6) for SVL. This difference was statistically significant (P = 0.005). Because the target CD34+ cell dose for a single transplant was 3 x 10(6)/kg at our institution, overall the LVL yields enough CD34+ cells that could allow for two transplants. Therefore, more patients in the LVL group were able to undergo a potential second transplant. Because of the reserved cells for a second transplant, LVL patients received significantly less CD34+ cell/kg per transplant than the patients in SVL group (P = <0.001). As a result, LVL group had statistically significant but clinically insignificant delay in neutrophil (P = <0.001) and platelet (P = 0.02) engraftments. Additionally, using LVL instead of SVL to collect >or=6 x 10(6)/kg CD34+ cells may potentially save $7,497 per patient. We therefore conclude that LVL is the method of choice for collection of multiple myeloma patients when two transplants are anticipated.

Investigation of the effect of BB-94 (batimastat) on the colonization potential of human lymphoma cells in SCID mice.

We have assessed the effectiveness of the metalloproteinase inhibitor BB-94 (batimastat) in reducing the colonization potential of the human Burkitt lymphoma Namalwa cell line. In this study Namalwa cells were injected intraperitoneally into SCID mice and their spread to the spleen, liver and lung studied over a 3 week period. The human cells were detected in the mouse tissues by polymerase chain reaction (PCR) amplification of a human alu repeat sequence. Comparison of BB-94-treated animals with an untreated control group provided no evidence for a significant reduction in the colonization of mouse tissues by the human lymphoma cells in the presence of the drug. Tumour growth, after subcutaneous injection of the Namalwa cells into SCID mice, was similarly unaffected by BB-94. The significance of these results is discussed.

Analysis of the colonization of unirradiated and irradiated SCID mice by human lymphoma and non-malignant lymphoid cells.

We have evaluated the severe combined immunodeficient (SCID) mouse as an in-vivo model for the study of non-Hodgkin's lymphomas (NHL). Characterization of the immune system of the animals in our SCID mouse colony was carried out to assess the numbers of lymphoid cells present, to determine natural killer (NK) cell activity as a function of age and to examine the histology of the lymphoid organs. In this study four human NHL established cell lines (Daudi, Namalwa, U937, MC116), lymphoma cells from four fresh NHL biopsies and normal peripheral blood mononuclear cells (PBMC) and bone marrow cells were investigated, after intraperitoneal injection into the mice. The presence of the human NHL cells in the peritoneum and spleen was assessed by FACS analysis. The colonization potential was investigated in a range of tissues by polymerase chain reaction (PCR) amplification of human repetitive sequences. These studies revealed clear differences in the abilities of the NHL cell types to colonize the SCID mice. Namalwa, Daudi and U937 cells demonstrated the highest efficiency of colonization and readily formed tumours, whereas MC116, the NHL biopsy cell populations and the non-malignant lymphoid cells showed little ability to survive and colonize other tissues in the SCID mice. Whole body irradiation of the SCID mice appeared to improve the survival of human PBMC, NHL biopsy cells and MC116 cells in the peritoneum, but had little effect on their colonization potential. The significance of these studies is discussed.

CD34(+) CD38(-) and CD34(+) HLA-DR(-) cells in BM stem cell grafts correlate with short-term engraftment but have no influence on long-term hematopoietic reconstitution after autologous transplantation.

BACKGROUND: Prior studies have demonstrated that relatively immature hematopoietic stem cells, including CD34(+) CD38(-) and CD34(+) HLA-DR(-) subsets, correlate with short-term hematopoietic reconstruction (SHR) after transplantation. The aim of this study was to investigate whether these immature CD34(+) subsets also correlate with long-term hematopoietic reconstitution (LHR) in recipients of ABMT. METHODS: We examined stem cell grafts from 58 patients with B-cell lymphoma or CLL who underwent ABMT after myeloablative conditioning. We determined whether total mononuclear cell dose (MNC), colony-forming unit-granulocyte-monocyte (CFU-GM), CD34(+) cell dose and CD34(+) cell subsets (CD34(+) CD38(-) and CD34(+) HLA-DR(-) were associated with SHR and/or LHR. Time to neutrophil engraftment (TNE) and time to platelet engraftment (TPE) were used to measure SHR, while platelet counts at day 100 and 1 year post-ABMT were used as indicators for LHR. RESULTS AND DISCUSSION: CD34(+) cell dose and CD34(+) cell subsets were significantly associated with SHR. However, at day 100 and 1 year post-transplant only total CD34(+) cell dose was associated with LHR. The association of total CD34(+) cell dose with LHR persisted after adjusting for age, sex and disease. None of the CD34(+) cell subsets analyzed showed evidence of significant association with LHR.