Faculty Bibliography

The continued use of pyrazinamide in the treatment of tuberculosis in the absence of a rapid, accurate and standardized pyrazinamide drug susceptibility assays is of great concern. While whole genome sequencing holds promise, it is not yet feasible option in low resource settings as it requires expensive instruments and bioinformatic analysis. We investigated the diagnostic performance of a closed-tube Linear-After-The-Exponential (LATE)-PCR assay for pyrazinamide susceptibility in Mycobacterium tuberculosis. Based on a set of 654 clinical Mycobacterium tuberculosis culture isolates with known mutations throughout the pncA gene as determined by Sanger sequencing, the assay displays excellent sensitivity of 96.9% (95% CI: 95.2-98.6) and specificity of 97.9% (95% CI: 96.1-99.7). In a subset of 384 isolates with phenotypic drug susceptibility testing, we also observed high sensitivity of 98.9% (95% CI: 97.5-100) but lower specificity of 91.8% (95% CI: 87.9-95.8) when compared to phenotypic drug susceptibility testing. We conclude that the LATE PCR assay offers both a rapid and accurate prediction of pyrazinamide susceptibility.

BACKGROUND:Chronic inflammation, innate immune activation, T-cell imbalance and endothelial activation have been linked with lung diseases. We sought to determine whether markers of these pathophysiologic pathways were associated with spirometry and chest computed tomography (CT) abnormalities among adolescents living with HIV (ALWH). SETTING/METHODS:Coptic Hope Center for Infectious Diseases in Nairobi, Kenya. METHODS:We performed a cross-sectional study of ALWH (10-19 years old). Participants underwent chest CT, spirometry, and venipuncture for serum biomarkers. We also collected demographic, anthropometric, T-cell subset, antiretroviral therapy, and exposure data. We compared characteristics and biomarkers by airflow obstruction [postbronchodilator FEV1/FVC z-score (zFEV1/FVC) < -1.64]. We used multivariable linear regression to determine associations of log10-transformed biomarkers and chest CT abnormalities with lower postbronchodilator zFEV1/FVC (airflow limitation). We performed exploratory principal components analysis on biomarkers, and determined associations of factors with postbronchodilator zFEV1/FVC and chest CT abnormalities. RESULTS:Of 47 participants with acceptable quality spirometry, 21 (45%) were female, median age was 13 years and 96% had perinatally-acquired HIV. Median CD4 was 672 cells/µL. Overall, 28% had airflow obstruction and 78% had a chest CT abnormality; airflow obstruction was associated with mosaic attenuation (P = 0.001). Higher endothelial activation (sVCAM-1, sICAM-1), inflammation and innate immune activation (serum amyloid-A, sTREM-1, sCD163), and T-cell imbalance (lower CD4/CD8) markers were associated with airflow limitation. Factors comprising endothelial and innate immune activation were associated with airflow limitation. CONCLUSIONS:Endothelial activation, innate immune activation, T-cell imbalance, and chronic inflammation are associated with airflow limitation and obstruction, providing insights into chronic lung disease pathophysiology among ALWH.

OBJECTIVES/OBJECTIVE:To examine the in vitro selection of aztreonam/avibactam resistance among MBL-producing Klebsiella pneumoniae and to understand the mechanism of increased resistance. METHODS:The MICs of aztreonam were determined with and without avibactam (4 mg/L) using a broth microdilution method. Single-step and multi-step mutant selection was conducted on five MBL-producing K. pneumoniae strains, including two dual carbapenemase producers. Genomic sequencing and gene cloning were performed to investigate the mechanism of increased resistance. RESULTS:We examined the MICs for 68 MBL-producing K. pneumoniae isolates, including 13 dual carbapenemase producers. Compared with aztreonam alone, the addition of avibactam (4 mg/L) reduced the MICs for all isolates by >128-fold, with MIC50 and MIC90 values of 0.25 and 1 mg/L, respectively. One NDM-1-, OXA-48-, CTX-M-15- and CMY-16-positive ST101 K. pneumoniae strain was selected to be resistant to aztreonam/avibactam, with a >16-fold increase in MIC (>128 mg/L). WGS revealed that the resistant mutants lost the blaNDM-1 gene, but acquired amino acid substitutions in CMY-16 (Tyr150Ser and Asn346His). Construction of blaCMY-16 mutants confirmed that the substitutions (Tyr150Ser and Asn346His) were primarily responsible for the decreased susceptibility to aztreonam/avibactam. In addition, transfer of blaCMY-16 mutant (Tyr150Ser and Asn346His) plasmid constructs into certain clinical carbapenemase-producing isolates demonstrated >64-fold increased MICs of aztreonam/avibactam and aztreonam/avibactam/ceftazidime. CONCLUSIONS:Aztreonam in combination with avibactam showed potent in vitro activity against MBL-producing K. pneumoniae. However, our study suggested the likelihood of aztreonam/avibactam resistance among MBL- and AmpC-co-producing strains and clinical practice should beware of the possibility of the emerging resistance.

Despite the rapid increase in the number of persons with dementia (PWD) receiving home health care (HHC), little is known of HHC services patterns to PWD of varied backgrounds, including language preference other than English. Analyzing data of 12,043 PWD from an urban home health agency, we found on average PWD received 2.48 skilled visits or 1.88-hour skilled care and 5.81 aide visits or 24.13-hour aide care weekly. Approximately 63% of the skilled visits were from nurses. More non-English preferred PWD received aide visits, compared to English preferred PWD (44% vs. 36%). The type and intensity of HHC services were associated with language preference; when stratified by insurance, non-English preference was still significantly associated with more HHC aide care. Our study indicated that HHC services (both type and amount) varied by language preference and insurance type as an indicator of access disparities was a significant contributor to the observed differences.

BACKGROUND:Hepatosplenic T-cell lymphoma (HSTCL) is a rare, poorly treatable malignancy associated with therapy for IBD. Current knowledge of HSTCL risk in IBD comes from an era of step-up therapy, before earlier use of biologics or combination therapy was advocated to achieve deep mucosal healing. HSTCL risk among newer biologic classes has also not been evaluated. AIMS/OBJECTIVE:To systematically characterise the association of HSTCL with biologic therapy for IBD. METHODS:We conducted a literature search and query of the Food and Drug Administration Adverse Event Reporting System to summarise HSTCL cases among IBD patients with prior biologic exposure. Demographics and immunosuppression exposure were extracted. Patients were stratified by current regimen (combination therapy, biologic monotherapy or no biologic), and biologic class (anti-TNF, anti-integrin, anti-interleukin 12/23). RESULTS:Sixty-two cases of HSTCL were identified from 2486 abstracts and 181 FDA Adverse Events Reporting System reports. The median age of affected patients was 28 years (range 12-81), and 83.6% were male, 84.7% had Crohn's disease. Five of 62 patients had no reported azathioprine/mercaptopurine exposure. Three patients within the cohort developed HSTCL after exposure to natalizumab, vedolizumab or ustekinumab; all three also had anti-TNF and azathioprine/mercaptopurine exposure. Forty-three of 49 (87.8%) patients with known outcomes died with a median survival of 5 months. CONCLUSIONS:Consistent with existing data, almost all identified HSTCL cases among IBD patients on biologic therapy had azathioprine/mercaptopurine exposure, and all cases on patients exposed to biologics had anti-TNF exposure. These data suggest initiating a patient-centred discussion before starting anti-TNF therapy or other biologics.

BACKGROUND:Little is known about the difference between black and non-black patients with epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC), particularly regarding survival. We thus characterized the EGFR expression profile, clinical characteristics, and survival outcome in these patients. PATIENT AND METHODS/METHODS:We reviewed the cancer registry and patient charts at a New York-Bronx network (n = 2773) treating a large population of minority patients, for non-squamous NSCLC (n = 1986) diagnosed between 2009 and 2015. Survival was adjusted for smoking, gender, age, weight, and stage. RESULTS:The EGFR mutation rate was 15% (98/652) in tested patients (black, 14%; non-black, 16%). There was no significant difference between the 2 cohorts with respect to age at diagnosis, gender, presenting stages, and socioeconomic status. On the other hand, weight was noted to be heavier in black patients with EGFR-mutated NSCLC than their non-black counterparts (P = .012). After adjusting for gender, age, smoking status, weight, and stage, the multivariate analysis revealed no racial disparity in survival among patients with wild-type EGFR (P = .774); However, among patients with EGFR-mutated NSCLC, black patients had shorter survival in comparison with non-black patients (P = .001), with 2-year survival rates being 33% versus 61%, respectively. Such shorter survival was also observed among EGFR-inhibitor treated patients with common EGFR mutations (P = .040). CONCLUSIONS:To our knowledge, this is the first report of inferior survival among black patients with NSCLC with EGFR mutations, relative to non-black patients. The survival disparities suggest the need of more tailored management for this patient population.

BACKGROUND:The benefits of computed tomography pulmonary angiography (CTPA) for pulmonary embolism (PE) diagnosis must be weighed against its risks, radiation-induced malignancy, and contrast-induced nephropathy. Appropriate use of CTPA can be assessed by monitoring yield, the percentage of tests positive for PE. We identify factors that are associated low CTPA yield, which may predict overtesting. METHODS:This was a retrospective cohort study of six emergency departments between June 2014 and February 2017. The electronic health record was queried for CTPAs ordered for adult patients in the emergency department. We assessed the following patient factors: age, gender, body mass index, number of comorbidities, race, and ethnicity, provider factors: type (resident, fellow, attending, physician assistant) and environment factors: test time of day, season of visit, and crowdedness of the department. RESULTS:A total of 14,782 CTPAs were reviewed, of which 1366 were found to be positive for PE, resulting in an overall CTPA yield of 9.24%. Provider type was not associated with a difference in yield. Testing was less likely to be positive in younger patients, females, those with lower body mass indexes and those identifying as Asian or Hispanic. Testing was also less likely to be positive when ordered during the overnight shift and during the winter and spring seasons. CONCLUSION:Our study identified several patient and environmental factors associated with low CTPA yield suggesting potential targets for overtesting. Targeting education and clinical decision support to assist providers in these circumstances may meaningfully improve yields.