Laura Bernhard

A multivariable analysis of factors influencing mucositis after autologous progenitor cell transplantation.

Mucositis is a common and vexing complication of autologous progenitor cell transplantation (ABMT). A modified oral mucositis assessment scale (OMAS) has been found to be a reproducible and effective tool for monitoring mucositis after radiation therapy or chemotherapy. We utilized the modified OMAS scale to study clinical parameters associated with the development of mucositis in 79 patients undergoing ABMT. Median patient age was 52; 61% had non-Hodgkins lymphoma (NHL), 23% multiple myeloma and 14% Hodgkins disease. Patients were mobilized with G-CSF alone or the combination of etoposide plus G-CSF. Univariable correlates of worse mucositis were prior radiation therapy (P = 0.004), a diagnosis of NHL (P = 0.014), progenitor cell mobilizing regimen containing etoposide (P = 0.001), and ABMT preparative regimen containing etoposide (P = 0.006). Multivariable regression analysis revealed that NHL diagnosis (P = 0.007), prior radiation therapy (P = 0.001), and etoposide in the mobilizing regimen (P = 0.034) were associated with worse post-transplant mucositis. Worsening mucositis correlated with a longer inpatient length of stay. We conclude that several variables contribute to worsening mucositis during autologous transplantation, including etoposide in the progenitor cell mobilizing regimen.

Influence of killer immunoglobulin-like receptor/HLA ligand matching on achievement of T-cell complete donor chimerism in related donor nonmyeloablative allogeneic hematopoietic stem cell transplantation

Achievement of complete donor chimerism (CDC) after allogeneic nonmyeloablative hematopoietic stem cell transplantation (NMHSCT) is important for preventing graft rejection and for generating a graft-vs-malignancy effect. The alloreactivity of NK cells and some T-cell subsets is mediated through the interaction of their killer immunoglobulin-like receptors (KIRs) with target cell HLA/KIR ligands. The influence of KIR matching on the achievement of T-cell CDC after NMHSCT has not been previously described. We analyzed 31 patients undergoing T-cell replete related donor NMHSCT following fludarabine and 200 cGy TBI. Recipient inhibitory KIR genotype and donor HLA/KIR ligand matches were used to generate an inhibitory KIR score from 1 to 4 based upon the potential number of recipient inhibitory KIRs that could be engaged with donor HLA/KIR ligands. Patients with a score of 1 were less likely to achieve T-cell CDC (P=0.016) and more likely to develop graft rejection (P=0.011) than those with scores greater than 1. Thus, patients with lower inhibitory KIR scores may have more active anti-donor immune effector cells that may reduce donor chimerism. Conversely, patients with greater inhibitory KIR scores may have less active NK cell and T-cell populations, which may make them more likely to achieve CDC.

The efficacy of prophylactic outpatient antibiotics for the prevention of neutropenic fever associated with high-dose etoposide (VP-16) for stem cell mobilization.

High-dose etoposide (2 g/m2) plus G-CSF is a very effective regimen for peripheral blood progenitor cell (PBPC) mobilization. Unfortunately, neutropenia is common. The infectious complications associated with high-dose etoposide have not been previously described. After noting a high incidence of hospitalizations for neutropenic fever, we began a vigorous prophylactic antibiotic regimen for patients receiving high-dose etoposide plus G-CSF, attempting to reduce infectious complications. Ninety-eight patients underwent etoposide mobilization between December 1997 and June 2000. Three chronological patient groups received: (1) no specific antibiotic prophylaxis (n = 44); (2) vancomycin i.v., cefepime i.v., clarithromycin p.o., and ciprofloxacin p.o. (n = 27); and (3) vancomycin i.v., clarithromycin p.o., and ciprofloxacin p.o. (n = 27). The patients not receiving antibiotic prophylaxis had a 68% incidence of hospitalization for neutropenic fever. In the patients receiving prophylaxis, the incidence was reduced to 26% and 15% respectively, for an overall incidence of 20% (P < 0.001 for comparison between prophylaxed and unprophylaxed groups). We conclude that etoposide mobilization is associated with a significant incidence of neutropenic fever, which can be substantially reduced by a vigorous antimicrobial prophylactic program.

Boost and loss of immune responses against tumor-associated antigens in the course of pregnancy as a model for allogeneic immunotherapy.

Donor-derived immunity against tumor-associated antigens (TAAs) may exert selective antileukemic activity reprieving the allogeneic recipient from graft-versus-host disease. As TAAs are highly expressed in placental tissues we hypothesized that pregnancy could drive respective immunity in healthy individuals. Thus, we investigated the frequency and level of immune responses against clinically relevant TAAs in 114 blood donors and 44 women during their first pregnancy. Quantitative reverse-transcription polymerase chain reaction was employed to detect low levels of interferon-γ after primary peptide stimulation of CD8(+) T lymphocytes. In blood donors, primary immune responses of low and/or high avidity were found against WT1 (15%), MUC1 (14%), PRAME (7%), and HER2/neu (5%) and exerted killing functions against leukemic cells. Men had higher responses than women, likely due to gonadal cancer-testis-antigen expression. Interestingly, a history of prior delivery was not associated with increased responses, whereas the strongest responses during pregnancy were found in early trimesters to disappear after delivery. This boost and loss of TAA-specific immunity suggests that virtually every donor harbors the potential to mount antileukemic immune responses in a recipient. However, in the absence of the driving target and a permissive environment, they are short-lived and thus require supplemental strategies such as vaccination or immunomodulation to facilitate their persistence.