Derek Tilley

CpaA a novel protease from Acinetobacter baumannii clinical isolates deregulates blood coagulation.

Acinetobacter baumannii is an important nosocomial pathogen that displays high antibiotic resistance. It causes a variety of infections including pneumonias and sepsis which may result in disseminated intravascular coagulation. In this work, we identify and characterize a novel secreted, zinc-dependent, metallo-endopeptidase CpaA (coagulation targeting metallo-endopeptidase of Acinetobacter baumannii) which deregulates human blood coagulation in vitro and thus is likely to contribute to A. baumannii virulence. Three quarters of the clinical isolates tested (n = 16) had the cpaA gene; however, it was absent from two type strains, A. baumannii ATCC 17978 and A. baumannii ATCC 19606. The CpaA protein was purified from one clinical isolate and was able to cleave purified factor (F) V and fibrinogen and reduce the coagulation activity of FV in human plasma. CpaA-treated plasma showed reduced clotting activity in contact pathway-activated partial thromboplastin time (aPTT) assays, but increased clotting activity in tissue factor pathway prothrombin time (PT) assays. A significant portion of clinically relevant A. baumannii isolates secrete a protease which targets and deregulates the coagulation system.

Comparative effectiveness analysis of different salvage therapy intensities used for diffuse large B-cell lymphoma in Northern or Southern Alberta: an instrumental variable analysis

Abstract To date, no clinical trial has addressed salvage therapy intensity for relapsed/refractory diffuse large B-cell lymphoma (DLBCL). We sought to determine whether the more intensive salvage chemotherapy approach used in Southern Alberta (SAB) compared to the conventional dose salvage approach used in Northern Alberta (NAB) affects the rates of autologous stem cell transplant (ASCT) and survival in patients with relapsed DLBCL. Using instrumental variable analysis, we examined 147 consecutive patients with relapsed/refractory DLBCL from 2004 to 2010 who received salvage therapy in SAB (n = 70) or NAB (n = 77). Patients treated in SAB had higher rates of: salvage chemotherapy response (85.0% vs. 54.0%, p = 0.001), ASCT (61.4% vs. 41.6%, p = 0.016) and 4-year overall survival (41% vs. 20%, p = 0.002) than those in NAB, respectively. This study supports the hypothesis that selective use of intensive salvage chemotherapy leads to higher rates of ASCT and survival in this population.

Real-world adjuvant TAC or FEC-D for HER2-negative node-positive breast cancer in women less than 50 years of age

PURPOSE We compared the efficacy, toxicity, and use of granulocyte colony-stimulating factor (g-csf) with tac (docetaxel-doxorubicin-cyclophosphamide) and fec-d (5-fluorouracil-epirubicin-cyclophosphamide followed by docetaxel) in women less than 50 years of age. METHODS The study included all women more than 18 years but less than 50 years of age with her2-negative, node-positive, stage ii or iii breast cancer diagnosed in Alberta between 2008 and 2012 who received tac (n = 198) or fec-d (n = 274). RESULTS The patient groups were well-balanced, except that radiotherapy use was higher in the tac group (91.9% vs. 79.9%, p < 0.001). At a median follow-up of 49.6 months, disease-free survival was 91.4% for tac and 92.0% for fec-d (p = 0.76). Overall survival (os) was 96% with tac and 95.3% with fec-d (p = 0.86).The incidences of grades 3 and 4 toxicities were similar in the two groups (all p > 0.05). Overall, febrile neutropenia (fn) was reported in 11.6% of tac patients and 15.7% of fec-d patients (p = 0.26). However, use of g-csf was higher in the tac group than in the fec-d group (96.4% vs. 71.5%, p < 0.001). Hospitalization for fn was required in 10.5% of tac patients and 13.0% of fec-d patients (p = 0.41). In g-csf-supported and -unsupported patients receiving tac, fn occurred at rates of 11.1% and 33.3% respectively (p = 0.08); in patients receiving the fec portion of fec-d, those proportions were 2.9% and 8.1% respectively (p = 0.24); and in patients receiving docetaxel after fec, the proportions were 4.1% and 17.6% respectively (p < 0.001). CONCLUSIONS In women less than 50 years of age receiving adjuvant tac or fec-d, we observed no differences in efficacy or other nonhematologic toxicities. Based on the timing and rates of fn, use of prophylactic g-csf should be routine for the docetaxel-containing portion of treatment; however, prophylactic g-csf could potentially be avoided during the fec portion of fec-d treatment.

An audit of referral and treatment patterns of high-risk prostate cancer patients in Alberta

INTRODUCTION We aimed to determine the impact of clinical practice guidelines (CPG) on rates of radiation oncologist (RO) referral, androgen-deprivation therapy (ADT), radiation therapy (RT), and radical prostatectomy (RP) in patients with high-risk prostate cancer (HR-PCa). METHODS All men >18 years, diagnosed with PCa in 2005 and 2012 were identified from the Alberta Cancer Registry. Patient age, aggregated clinical risk group (ACRG) score, Gleason score (GS), pre-treatment prostate-specific antigen (PSA), RO referral, and treatment received were extracted from electronic medical records. Logistic regression modelling was used to examine associations between RO referral rates and relevant factors. RESULTS HR-PCa was diagnosed in 261 of 1792 patients in 2005 and 435 of 2148 in 2012. Median age and ACRG scores were similar in both years (p>0.05). The rate of patients with PSA >20 were 67% and 57% in 2005 and 2012, respectively (p=0.004). GS ≤6 was found in 13% vs. 5% of patients, GS 7 in 27% vs. 24%, and GS ≥8 in 59% vs. 71% in 2005 and 2012, respectively (p<0.001). In 2005, RO referral rate was 68% compared to 56% in 2012 (p=0.001), use of RT + ADT was 53% compared to 32% (p<0.001), and RP rate was 9% vs. 17% (p=0.002). On regression analysis, older age, 2012 year of diagnosis and higher PSA were associated with decreased RO referral rates (odds ratios [OR] 0.49, 95% confidence interval [CI] 0.39-0.61; OR 0.51, 95% CI 0.34-0.76; and OR 0.64, 95% CI 0.39-0.61), respectively [p<0.001]). CONCLUSIONS Since CPG creation in 2005, RO referral rates and ADT + RT use declined and RP rates increased, which demonstrates a need to improve adherence to CPG in the HR-PCa population.