With favorable regenerative and immunotolerant profiles, patient-derived human mesenchymal stem cells (hMSCs) are increasingly considered in cell therapy. Derived from bone marrow (BM) and standardized with culture in fetal bovine serum (FBS), translation of hMSC-based approaches is impeded by protracted expansion times, risk of xenogenic response, and exposure to zoonoses. Here, human platelet lysate adherent to good manufacturing practices (GMP-hPL) provided a nonzoonotic adjuvant that enhanced the capacity of BM-hMSC to proliferate. The nurturing benefit of GMP-hPL was generalized to hMSC from adipose tissue evaluated as an alternative to bone marrow. Long-term culture in GMP-hPL maintained the multipotency of hMSC, while protecting against clonal chromosomal instability detected in the FBS milieu. Proteomic dissection identified TGF-β, VEGF, PDGF, FGF, and EGF as highly ranked effectors of hPL activity, revealing a paradigm of healing that underlies platelet lysate adjuvancy. Thus, GMP-adherent human platelet lysate accelerates hMSC proliferation with no chromosomal aberrancy, through an innate repair paradigm.

Summary:Absolute lymphocyte count at day 15 (ALC-15) after autologous peripheral blood hematopoietic stem cell transplantation (APHSCT) is an independent prognostic factor for survival in non-Hodgkin's lymphoma (NHL). Factors affecting ALC-15 remain unknown. We hypothesized that dose of infused autograft lymphocytes (A-ALC) directly impacts upon ALC-15. A total of 190 consecutive NHL patients received A-ALC between 1993 and 2001. The primary end point was correlation between A-ALC and ALC-15. A strong correlation was identified (r ¼ 0.71). A higher A-ALC was infused into patients achieving an ALC-15 X500/ll vs ALC-15 o500/ll (median of 0.68 Â 10 9 /kg (0.04-2.21 Â 10 9 /kg), vs 0.34 Â 10 9 /kg (0.04-1.42 Â 10 9 /kg), Po0.0001). The median follow-up for all patients was 36 months (maximum of 109 months). The A-ALC threshold was determined at 0.5 Â 10 9 /kg. The median overall survival (OS) and progression-free survival (PFS) times were longer in patients who received an A-ALC X0.5 Â 10 9 /kg vs A-ALC o0.5 Â 10 9 /kg (76 vs 17 months, Po0.0001; 49 vs 10 months, Po0.0001, respectively). Multivariate analysis demonstrated A-ALC to be an independent prognostic indicator for OS and PFS. These data support our hypothesis that ALC-15 and survival are dependent upon the dose of infused A-ALC in NHL.

Absolute lymphocyte count at day 15 (ALC-15) after autologous peripheral blood hematopoietic stem cell transplantation (APHSCT) is an independent prognostic factor for survival in multiple myeloma (MM); however, factors affecting ALC-15 in MM remain unknown. We hypothesized that the dose of infused peripheral blood autograft lymphocytes (autograft absolute lymphocyte count: A-ALC) impacts ALC-15 recovery. Between 1989 and 2001, 267 consecutive MM patients underwent APHSCT. We set out to determine the correlation between A-ALC and ALC-15 and the utility of A-ALC as a marker for ALC-15 recovery. A-ALC was found to be both a strong predictor for area under curve (AUC ¼ 0.93; P ¼ 0.0001) and strongly correlated with (r s ¼ 0.83; P ¼ 0.0001) ALC-15 recovery. Higher infused A-ALC was significantly correlated with an ALC-15X500/ll. In addition, median post-transplant overall survival (OS) and time to progression (TTP) were longer in patients who received an A-ALCX0.5 Â 10 9 lymphocytes/kg versus A-ALC o0.5 Â 10 9 lymphocytes/kg (58 vs 30 months, P ¼ 0.00022; 22 vs 15 months, Po0.00012, respectively). Multivariate analysis demonstrated A-ALC as an independent prognostic indicator for OS and TTP. These results indicate that an infused dose of autograft lymphocytes significantly impacts clinical outcome post-APHSCT in MM.

Folate receptor alpha (FR) is overexpressed in several cancers. Endogenous immunity to the FR has been demonstrated in patients and suggests the feasibility of targeting FR with vaccine or other immune therapies. CD4 helper T cells are central to the development of coordinated immunity, and prior work shows their importance in protecting against relapse. Our previous identification of degenerate HLA-class II epitopes from human FR led to the development of a broad coverage epitope pool potentially useful in augmenting antigen-specific immune responses in most patients. We conducted a phase I clinical trial testing safety and immunogenicity of this vaccine, enrolling patients with ovarian cancer or breast cancer who completed conventional treatment and who showed no evidence of disease. Patients were initially treated with low-dose cyclophosphamide and then vaccinated 6 times, monthly. Immunity and safety were examined during the vaccine period and up to 1 year later. Vaccination was well tolerated in all patients. Vaccine elicited or augmented immunity in more than 90% of patients examined. Unlike recall immunity to tetanus toxoid (TT), FR T-cell responses developed slowly over the course of vaccination with a median time to maximal immunity in 5 months. Despite slow development of immunity, responsiveness appeared to persist for at least 12 months. The results demonstrate that it is safe to augment immunity to the FR tumor antigen, and the developed vaccine is testable for therapeutic activity in most patients whose tumors express FR, regardless of HLA genotype. .

Vaccines are attractive as consolidation therapy after autologous stem cell transplantation (ASCT) for multiple myeloma (MM). We report the results of a phase II trial of the immunotherapeutic, APC8020 (Mylovenge TM ), given after ASCT for MM. We compared the results with that of other patients with MM who underwent ASCT at Mayo Clinic during the same time period. Twenty-seven patients were enrolled on the trial between July, 1998 and June, 2001, and the outcomes were compared to that of 124 consecutive patients transplanted during the same period, but not enrolled on the trial. The median (range) follow-up for patients still alive from the vaccine trial is 6.5 (2.9-8 years), and 7.1 (6-8 years) in the control group. The median age was 57.4 range (36.1-71.3) in the DB group and 56.4 (range, 30-69) in the trial group. Known prognostic factors including PCLI, B2M, and CRP were comparable between the groups. The median overall survival for the trial patients was 5.3 years (95% CI: 4.0 years-N/A) compared to 3.4 years (95% CI: 2.7-4.6 years) for the DB group (P 5 0.02). The median time to progression and progression-free survival for the trial group was similar to the DB group. Although not a controlled trial, the vaccines given after ASCT appear to be associated with improved overall survival compared to historical controls. This approach warrants further investigation to confirm this and define the role of vaccine therapy in myeloma. Am. J. Hematol. 84:799-802, 2009. V