Overall survival of patients with cHL who progress after autologous stem cell transplant: results in the novel agent era

In the pre-novel agent era, the median postprogression overall survival (PPS) of patients with classic Hodgkin lymphoma (cHL) who progress after autologous stem cell transplant (ASCT) was 2 to 3 years. Recently, checkpoint inhibitors (CPI) and brentuximab vedotin (BV) have improved the depth and durability of response in this population. Here, we report the estimate of PPS in patients with relapsed cHL after ASCT in the era of CPI and BV. In this multicenter retrospective study of 15 participating institutions, adult patients with relapsed cHL after ASCT were included. Study objective was postprogression overall survival (PPS), defined as the time from posttransplant progression to death or last follow-up. Of 1158 patients who underwent ASCT, 367 had progressive disease. Median age was 34 years (range, 27-46) and 192 were male. Median PPS was 114.57 months (95% confidence interval [CI], 91-not achieved) or 9.5 years. In multivariate analysis, increasing age, progression within 6 months, and pre-ASCT positive positron emission tomography scan were associated with inferior PPS. When adjusted for these features, patients who received CPI, but not BV, as first treatment for post-ASCT progression had significantly higher PPS than the no CPI/no BV group (hazard ratio, 3.5; 95% CI, 1.6-7.8; P = .001). Receipt of allogeneic SCT (Allo-SCT) did not improve PPS. In the era of novel agents, progressive cHL after ASCT had long survival that compares favorably with previous reports. Patients who receive CPI as first treatment for progression had higher PPS. Receipt to Allo-SCT was not associated with PPS in this population.

Codominant Role of Interferon-γ- and Interleukin-17-Producing T Cells During Rejection in Full Facial Transplant Recipients

Facial transplantation is a life-changing procedure for patients with severe composite facial defects. However, skin is the most immunogenic of all transplants, and better understanding of the immunological processes after facial transplantation is of paramount importance. Here, we describe six patients who underwent full facial transplantation at our institution, with a mean follow-up of 2.7 years. Seum, peripheral blood mononuclear cells, and skin biopsy specimens were collected prospectively, and a detailed characterization of their immune response (51 time points) was performed, defining 47 immune cell subsets, 24 serum cytokines, anti-HLA antibodies, and donor alloreactivity on each sample, producing 4269 data points. In a nonrejecting state, patients had a predominant T helper 2 cell phenotype in the blood. All patients developed at least one episode of acute cellular rejection, which was characterized by increases in interferon-γ/interleukin-17-producing cells in peripheral blood and in the allograft's skin. Serum monocyte chemotactic protein-1 level was significantly increased during rejection compared with prerejection time points. None of the patients developed de novo donor-specific antibodies, despite a fourfold expansion in T follicular helper cells at 1 year posttransplantation. In sum, facial transplantation is frequently complicated by a codominant interferon-γ/interleukin-17-mediated acute cellular rejection process. Despite that, medium-term outcomes are promising with no evidence of de novo donor-specific antibody development.

Serine protease inhibitor-6 differentially affects the survival of effector and memory alloreactive CD8-T cells

The clonal expansion of effector T cells and subsequent generation of memory T cells are critical in determining the outcome of transplantation. While cytotoxic T lymphocytes induce direct cytolysis of target cells through secretion of Granzyme-B (GrB), they also express cytoplasmic serine protease inhibitor-6 (Spi6) to protect themselves from GrB that has leaked from granules. Here, we studied the role of GrB/Spi6 axis in determining clonal expansion of alloreactive CD8-T cells and subsequent generation of memory CD8-T cells in transplantation. CD8-T cells from Spi6(-/-) mice underwent more GrB mediated apoptosis upon alloantigen stimulation in vitro and in vivo following adoptive transfer into an allogeneic host. Interestingly, while OT1.Spi6(-/-) CD8 T cells showed significantly lower clonal expansion following skin transplants from OVA mice, there was no difference in the size of the effector memory CD8-T cells long after transplantation. Furthermore, lack of Spi6 resulted in a decrease of short-lived-effector-CD8-cells but did not impact the pool of memory-precursor-effector-CD8-cells. Similar results were found in heart transplant models. Our findings suggest that the final alloreactive CD8-memory-pool-size is independent from the initial clonal-proliferation as memory precursors express low levels of GrB and therefore are independent of Spi6 for survival. These data advance our understanding of memory T cells generation in transplantation and provide basis for Spi6 based strategies to target effector T cells.

Essential role of PDL1 expression on nonhematopoietic donor cells in acquired tolerance to vascularized cardiac allografts

The PD1:PDL1 pathway is an essential negative costimulatory pathway that plays a key role in regulating the alloimune response. PDL1 is expressed not only on antigen-presenting cells (APCs) but also cardiac endothelium. In this study, we investigated the importance of PDL1 expression on donor cardiac allograft in acquired transplantation tolerance in a fully MHC-mismatched model. We generated PDL1 chimeric mice on B6 background that expressed PDL1 on either hematopoietic cells or nonhematopoietic cells of the heart. Sham animals were used as controls. These hearts were then transplanted into BALB/c recipients and treated with CTLA4-Ig to induce tolerance. Cardiac endothelium showed significant expression of PDL1, which was upregulated upon transplantation. While the absence of PDL1 on hematopoietic cells of the heart resulted in delayed rejection and prevented long-term tolerance in most but not all recipients, we observed an accelerated and early graft rejection of all donor allografts that lacked PDL1 on the endothelium. Moreover, PDL1-deficient endothelium hearts had significant higher frequency of IFN-γ-producing alloreactive cells as well as higher frequency of CD8(+) effector T cells. These findings demonstrate that PDL1 expression mainly on donor endothelium is functionally important in a fully allogeneic mismatched model for the induction of cardiac allograft tolerance.

Donor antioxidant strategy prolongs cardiac allograft survival by attenuating tissue dendritic cell immunogenicity(†)

Ischemic reperfusion injury (IRI) enhances allograft immunogenicity, worsens transplantation outcome, and is the primary cause of activation of the recipient innate immune response, resulting in subsequent amplification of the alloimmune adaptive response. Here, we aimed at demonstrating that the link between innate injury and alloimmunity occurs predominantly through activation of allograft-derived dendritic cells (ADDC). Perfusion of MCI-186, a free radical scavenger, into donor cardiac allografts prior to transplantation resulted in prolongation of complete MHC-mismatched allograft survival in the absence of immunosuppression (MST of 8 vs. 26 days). This prolongation was associated with a reduction in trafficking of ADDC to recipient lymphoid tissue as well as a reduction in T cell priming. Depleting ADDC with diphtheria toxin (using DTR-GFP-DC mice as donors) 24 h prior to transplant resulted in abrogation of the prolongation observed with MCI-186 treatment, demonstrating that the beneficial effect of MCI-186 is mediated by ADDC. This donor-specific anti-ischemic regimen was also shown to reduce chronic rejection, which represents the primary obstacle to long-term allograft acceptance. These data for the first time establish a basis for donor anti-ischemic strategies, which in the ever-expanding marginal donor pools, can be instituted to promote engraftment.

Changing demographics of locally advanced breast cancer: Data from a regional cancer centre

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Background: Locally advanced breast cancer (LABC) (including inflammatory breast cancer (IBC)) accounts for less than 5% of women diagnosed with breast cancer in North America each year. This population of women continues to represent a challenge in terms of timely diagnosis and treatment. Methods: A retrospective database was developed using the American Joint Committee on Cancer (AJCC)2002 staging classification for all women who presented to TOHRCC with LABC between Jan 1/02 - April 1/05. Information was abstracted from clinic charts and the patient self-reported health questionnaires. Results: These results reflect the demographics of the first 50 women entered into our database. Median age at presentation was 57 years (range 28–88); 62% were post-menopausal and 28% had a 1st/2nd degree relative with breast cancer. Clinical diagnosis was made by: self-detection (79%); mammography (5%), routine physical exam (9%) and CT scan (2%). Clinical tumour stage at presentation was: IIIA (25.6%); IIIB (53.5%) and IIIC (9.3%). The majority of women were diagnosed with infiltrating ductal carcinoma (72%). Women with T4d tumours (IBC) (38%) tended to be younger (54.5 vs 59.2 years); presented earlier (2.7 vs. 6.3 months); had larger tumours at the time of diagnosis (9.7 vs 5.5 cm); were more likely grade III (30 vs 20%) and were more often ER negative (42.1% vs 33.3%) and PR negative (63.2% vs. 50%). Only 13% of women in this database were tested for HER-2 of whom 70% were positive. Conclusions: This data utilizing the new AJCC (2002) staging system reflects important shifts in LABC that will influence clinical care in the future. Compared to historical databases, patients tended to be younger and have more aggressive disease including ER negative and HER-2 positive disease. Supplemental microarray studies to further explore this entity are planned. We will present clinical management outcomes in an additional submission.

No significant financial relationships to disclose.

Trends in systemic management (SM) for the treatment of locally advanced breast cancer: Data from a regional cancer centre

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Background: Locally advanced breast cancer (LABC) accounts for less than 5% of women diagnosed with breast cancer in North America each year. The scarcity of clinical trials addressing the SM of these women continues to represent a challenge for clinicians. Methods: A retrospective database was developed using the American Joint Committee on Cancer (AJCC) 2002 staging classification for all women who presented to TOHRCC with LABC between Jan 1/02-April 1/05. Information was obtained from clinic charts and patient self-reported questionnaires. Results: Outcomes reflect the SM of the first 50 women entered into our database. Median age at presentation was 57 years (range 28–88); 62% were post-menopausal; and hormonal status was 52% estrogen receptor (ER) positive and 54% progesterone receptor (PR) positive. Surgery was performed prior to chemotherapy in 50% of patients (pts).The majority (90%) of pts received SM as follows: 38% anthracyclines (A) alone (52% epirubicin, 26% adriamycin, 2% both); 7% taxanes (T) alone (33% paclitaxel, 66% docetaxel), 53% received both T and A regimens, and 2% received other types of chemotherapy (gemcitabine,vinorelbine,capecitabine). The addition of trastuzumab to the SM of HER2-positive pts has also been observed. Hormone therapy was given to 22 pts (44%) of whom 82% were ER or PR-positive: tamoxifen (27%); aromatase inhibitors (AIs; 50%); both tamoxifen and AIs (23%). Pts were treated with AIs as follows: anastrozole (73%); fulvestrant (9%), and atemestane (9%). In pts with measurable disease receiving neoadjuvant SM; 7(35%) had a complete clinical response and 13 (65%) had a partial response; mean tumour size decreased from 7.5 cm (range 2–22) to 2.8 cm (range 0–8). Pathological complete response rates and improved survival rates have been observed and will be reported in detail. Conclusions: These results represent our first analysis of treatment outcomes in women with LABC using the new AJCC system. This database highlights the increased utilization of T and AIs in the SM of these pts, which seems to translate into the increasingly observed improvements in overall survival. Microarray studies to further explore predictability of treatment outcomes are planned.

No significant financial relationships to disclose.

Photochemical activity of single chloroplasts recorded by the use of nuclear track emulsion

The photochemistry done by single chloroplasts can be measured when the chloroplasts are embedded in nuclear track emulsion. It has been known for more than 50 years that certain chemicals will blacken photographic plates (chemical fogging). Although this effect has been little used to measure chemical reactions, it may be particulary useful in photochemistry and electrochemistry, since as little as 10(-18) mole can be measured.