Whole-genome sequencing differentiates relapse from re-infection in TB

BACKGROUND: Distinguishing TB relapse from re-infection is important from a clinical perspective to document transmission patterns. We investigated isolates from patients classified as relapse to understand if these were true relapses or re-infections. We also investigated shifts in drug susceptibility patterns to distinguish acquired drug resistance from re-infection with resistant strains.METHODS: Isolates from pulmonary TB patients from 2009 to 2017 were analysed using whole-genome sequencing (WGS).RESULTS: Of 11 patients reported as relapses, WGS results indicated that 4 were true relapses (single nucleotide polymorphism difference ≤5), 3 were re-infections with new strains, 3 were both relapse and re-infection and 1 was a suspected relapse who was later categorised as treatment failure based on sequencing. Of the 9 patients who went from a fully susceptible to a resistant profile, WGS showed that none had acquired drug resistance; 6 were re-infected with new resistant strains, 1 was probably infected by at least two different genotype strains and 2 were phenotypically misclassified.CONCLUSIONS: WGS was shown to distinguish between relapse and re-infection in an unbiased way. The use of WGS minimises the risk of false classification of treatment failure instead of re-infection. Furthermore, our study showed that strains without major genetic differences can cause re-infection.

Recovery potential of transplanted oligoprogenitor cells derived from human dental pulp stem cells in Lysophosphatidyl choline demyelination mode

IM: Here we used a demyelination model using an injection of Lysophosphatidylcholine )LPC( in the corpus collosum to examine the myelination activity of differentiated oligodendrocytes derived from Human dental pulp stem cells )hDPDSCs( according to a two step induction protocol.

METHODS AND MATERIALS

The cells were cultured in DMEM-F12 medium containing 1M Retinoic acid and were treated with 5ng/ml platelet-derived growth factor, 10 ng/ml basic fibroblast growth factor for 8-10 days. The differentiation cells were examined via the expression of specific glial markers: Olig2 and O4. Cells were transplanted in to a demylinated rat corpus callosum. The alteration of the demyelination extension as well as remyelination intensity was examined via a specific myelin staining: Luxol Fast Blue and immunohistochemistry.

RESULTS

Differentiated oligoprogenitor cells were confirmed via immunofluorescence staining with specific glial markers: Olig2 and O4. Also, the amount of demyelination was decreased and intensity of remyelination showed an increase after an engraftment of differentiated cells. Immunohistochemistry for evaluation of PLP expression proved the mature myelinating oligodendrocytes.

CONCLUSION

hDPSCs can be induced to transdifferentiate into oligoprogenitor cells and respond to the routinely applied regents for glial differentiation of Mesenchymal stem cells. hDPSCs may be a valuable source for cell therapy in neurodegenerative diseases (Fig. 4, Ref. 30). Text in PDF www.elis.sk Keywords: dental pulp stem cells, lysophosphatidylcholine, corpus callosum, oligodendrocyte, differentiation.

Common isolation of New Delhi metallo-beta-lactamase 1-producing Enterobacteriaceae in a large surgical hospital in Vietnam

This study sought to monitor the presence of carbapenem-resistant Enterobacteriaceae (CRE) and the proportion New Delhi metallo-beta-lactamase 1 (NDM-1)-producing bacteria between August 2010 and December 2012 in a surgical hospital in Vietnam. We identified 47 CRE strains from a total of 4,096 Enterobacteriaceae isolates (1.1 %) that were NDM-1-positive from 45 patients admitted to 11 different departments, with the majority being from the urology department. The NDM-1 gene was found in seven different species. Genotyping revealed limited clonality of NDM-1-positive isolates. Most of the isolates carried the NDM-1 gene on a plasmid and 17.8 % (8/45) of those were readily transferable. We found five patients at admission and one patient at discharge with NDM-1-positive bacteria in their stool. From 200 screening environmental hospital samples, five were confirmed to be NDM-1-positive and included Acinetobacter species (n = 3) and Enterobacter aerogenes (n = 2). The results reveal that NDM-1-producing Enterobacteriaceae are commonly isolated in patients admitted to a Vietnamese surgical hospital and are also detected in the hospital environment.

Abstract P3-02-11: Screening Magnetic Resonance Imaging (MRI) of the breast in women at increased lifetime risk for breast cancer: A retrospective single institution study

Background: Multiple factors are associated with an increased lifetime risk of breast cancer, including inheritance of an abnormal BRCA 1/2 gene, history of lobular carcinoma in situ (LCIS) or atypical hyperplasia, family history of breast cancer or previous chest wall radiation. In 2007, the American Cancer Society released updated guidelines for breast cancer screening based on risk stratification. These guidelines added annual MRI screening to mammography for women with greater than or equal to a 20–25% lifetime risk. Breast MRI screening trials have consistently demonstrated a higher sensitivity of MRI for malignancy compared with mammography, with an additional cancer yield from MRI of approximately 3%. The purpose of this study was to evaluate MRI screening outcomes in women with an increased risk for breast cancer evaluated in an established breast subspecialty clinic within the University of Wisconsin (UW) Hospital and Clinics.

Methods: Patients (Pts) were included if they were seen by a UW breast center nurse practitioner, medical or surgical oncologist between 1/1/2007–3/1/2011 with a diagnosis code of: family history of breast or ovarian cancer, genetic susceptibility to malignant neoplasm or genetic carrier, Hodgkin's disease, LCIS, or atypical hyperplasia. Pts with a co-existing diagnosis of invasive breast cancer or ductal carcinoma in situ prior to initial encounter were excluded. Demographic information, breast cancer risk factors, estimated lifetime risk of breast cancer and screening recommendations were abstracted from the medical record. Results of subsequent breast imaging examinations (including breast MRI, diagnostic and screening mammography, and image-guided biopsies) were analyzed with the use of the mammography information system (PenRad™).

Results: Of 276 women who met the inclusion criteria, 148 underwent at least 1 screening breast MRI. The majority of MRI screened pts were premenopausal (82%) and Caucasian (96.6%) with a mean age of 42.5 (range 20–68) at their initial encounter. Eighty five percent had a first degree relative with breast cancer and 72.3% of pts undergoing MRI screening had a documented lifetime risk of breast cancer of 20% or greater using a validated model. Within this MRI-screened cohort, 18.2% had a known genetic predisposition to breast cancer. Over the time assessed, 307 MRIs were performed in the 148 pts. Biopsy was recommended and performed based on the results of the MRI in 31 of 307 exams (10%). Ten cancers were detected for a positive predictive value based on biopsy performed of 32% and an overall cancer yield of 3.3% (10 of 307 MRI exams). All cancers were stage 0 - II. All pts are currently with no evidence of disease.

Conclusion: Breast MRI has a high positive predictive value and cancer yield with an acceptable biopsy rate in a diverse group of high risk women undergoing breast MRI at an academic center outside of a clinical trial.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-02-11.

P4-11-21: A Retrospective Analysis of Women at Increased Lifetime Risk for Breast Cancer: Referral Patterns to Subspecialty Providers, Recommendations and Outcomes

Background: Inheritance of an abnormal BRCA 1/2 gene, a family history of breast cancer (BrCa), or a personal history of lobular carcinoma in situ (LCIS), atypical hyperplasia, or chest wall radiation can significantly increase an individual's lifetime risk for developing BrCa. In 2007, the American Cancer Society (ACS) released updated guidelines for screening in women with a lifetime risk of BrCa ≥20-25%. These guidelines added MRI screening to annual mammography. The objective of our analysis is to characterize patients referred after the release of the 2007 ACS guidelines to subspecialty providers specifically for evaluation of BrCa risk and analyze subsequent screening and risk reduction recommendations in the cohort of patients (pts) with a predicted increased lifetime risk for BrCa.

Methods: Pts seen at a single center (University of Wisconsin [UW]) between 1/2007-3/2011 by medical, surgical and/or gynecology-oncology for an increased lifetime risk of BrCa were identified by billing codes or evaluation in the UW Breast Cancer Prevention, Assessment and Tailored Health Screening (PATHS) Clinic. Pts with a personal history of BrCa prior to 1/2007 are excluded. Patients with a known genetic predisposition to BrCa, family history of breast cancer, or a personal history of LCIS, atypical hyperplasia or chest wall radiation are included in this analysis. All charts will be evaluated for documentation of the individual's lifetime risk of BrCa and method used for risk-assessment, recommended and performed screening tests, concordance with ACS screening guidelines, patient adherence to initial and subsequent screening recommendations, and uptake of risk reduction strategies. Call-back rates for additional or follow-up imaging and/or biopsy following BrCa screening and characteristics of all new BrCa diagnoses will be collected.

Results: 240 eligible pts were seen during the study period. 15% of pts referred had a known genetic predisposition to BrCa. Most pts (75%) were referred for a family history of BrCa. The majority of these pts had a predicted lifetime risk of BrCa in excess of 20%, with less than 10% of patients being referred having a lifetime risk <20%. The remaining pts were referred for a personal history of LCIS, atypical hyperplasia or previous radiation to the chest wall. Results including subspecialty provider BrCa risk assessment, screening and risk-reduction recommendations, patient uptake and adherence, outcomes of screening and characteristics of diagnosed BrCa cases will be presented.

Conclusion: Pts with a predicted increased lifetime risk for BrCa are often evaluated by oncology subspecialty providers. The primary factor related to referral is family history of BrCa. The majority of patients referred to a subspecialty provider have a calculated lifetime risk for BrCa in excess of 20%. This study evaluates provider assessment of BrCa risk and subsequent recommendations for screening and discussion of risk reduction strategies.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-21.