The Tumor Antigen Cyclin B1 Hosts Multiple CD4 T Cell Epitopes Differently Recognized by Pre-Existing Naive and Memory Cells in Both Healthy and Cancer Donors

International audienceCyclin B1 (CCNB1) is considered as a potential target for a cancer vaccine, as it is overexpressed in many malignant cells, while being transiently expressed in normal cells. To evaluate the CD4 T cell response to CCNB1, we derived T cell lines by multiple weekly rounds of stimulation with recombinant CCNB1 of T cells collected in healthy donors (long-term T cell assays). T cell lines were specific for 15 immunodominant peptides and derived preferentially from naive T cells. From 74 overlapping peptides, 20 peptides were selected for their broad specificity of binding to HLA class II molecules and included most of the immunodominant epitopes. They primed in vitro a large number of specific CD4 T cell lines in all the donors. Immunodominant epitopes were the most efficacious in long-term T cell assays, both in terms of number of specific T cell lines and number of responding donors. The 20 peptides were also submitted to short-term T cell assays using cells collected in healthy and cancer patients with the aim to evaluate the memory response. The recognized peptides differed from the immunodominant peptides and were part of the best promiscuous peptides. We also observed pre-existing CCNB1-specifc IgG Abs in both healthy and cancer donors. Long-and short-term T cell assays revealed that CCNB1 contained many CD4 T cell epitopes, which are differentially recognized by pre-existing naive and memory CD4 T cells. These observations are of value for the design of cancer vaccines

Clinic HIV-Focused Features and Prevention of Pneumocystis Carinii Pneumonia

OBJECTIVE: To examine the association of clinic HIV-focused features and advanced HIV care experience with Pneumocystis carinii pneumonia (PCP) prophylaxis and development of PCP as the initial AIDS diagnosis. DESIGN: Nonconcurrent prospective study. SETTING: New York State Medicaid Program. PARTICIPANTS: Medicaid enrollees diagnosed with AIDS in 1990–1992. MEASUREMENTS AND MAIN RESULTS: We collected patient clinical and health care data from Medicaid files, conducted telephone interviews of directors of 125 clinics serving as the usual source of care for study patients, and measured AIDS experience as the cumulative number of AIDS patients treated by the study clinics since 1986. Pneumocystis carinii pneumonia prophylaxis in the 6 months before AIDS diagnosis and PCP at AIDS diagnosis were the main outcome measures. Bivariate and multivariate analyses adjusted for clustering of patients within clinics. Of 1,876 HIV-infected persons, 44% had PCP prophylaxis and 38% had primary PCP. Persons on prophylaxis had 20% lower adjusted odds of developing PCP (95% confidence interval [CI] 0.64, 0.99). The adjusted odds of receiving prophylaxis rose monotonically with the number of HIV-focused features offered by the clinic, with threefold higher odds (95% CI 1.6, 5.7) for six versus two or fewer such features. Patients in clinics with three HIV-focused features had 36% lower adjusted odds of PCP than those in clinics with one or none. Neither clinic experience nor specialty had a significant association with prophylaxis or PCP. CONCLUSIONS: PCP prevention in our study cohort appears to be more successful in clinics offering an array of HIV-focused features

Cost-utility of the 21-gene recurrence score assay in node-negative and node-positive breast cancer

The 21-gene recurrence score (Oncotype DX: RS) appears to augment clinico-pathologic prognostication and is predictive of adjuvant chemotherapy benefit in node-negative (N-) and node-positive (N+), endocrine-sensitive breast cancer. RS is a costly assay that is associated with good 'value for money' in N- disease, while economic evaluations in N+ disease based on most recent data have not been conducted. We examined the cost-utility (CU) of a RS-guided adjuvant strategy, compared to current practice without RS in N- and N+, endocrine-sensitive, breast cancer from a Canadian health care system perspective. A generic state-transition model was developed to compute cumulative costs and quality-adjusted life years (QALYs) over a 25-year horizon. Patient outcomes with and without chemotherapy in RS-untested cohorts and in those with low, intermediate and high RS were examined based on the reported prognostic and predictive impact of RS in N- and N+ disease. Chemotherapy utilization (current vs. RS-guided), unit costs and utilities were derived from a Nova Scotia Canadian population-based cohort, local unit costs and the literature. Costs and outcomes were discounted at 3% annually, and costs were reported in 2011 Canadian dollars ($). Probabilistic and one-way sensitivity analyses were conducted for key model parameters. Compared to a non-RS-guided strategy, RS-guided adjuvant therapy was associated with$2,585 and $864 incremental costs, 0.27 and 0.06 QALY gains, and resultant CUs of$9,591 and $14,844 per QALY gained for N- and N+ disease, respectively. CU estimates were robust to key model parameters, and were most sensitive to chemo utilization proportions. RS-guided adjuvant therapy appears to be a cost-effective strategy in both N- and N+, endocrine-sensitive breast cancer with resultant CU ratios well below commonly quoted thresholds