Divergence in Cigarette Discontinuation Rates by Use of Electronic Nicotine Delivery Systems (ENDS): Longitudinal Findings From the United States PATH Study Waves 1-6.

INTRODUCTION: We compare real-world trends in population-level cigarette discontinuation rates among adults (ages ≥21) who smoked cigarettes, by electronic nicotine delivery systems (ENDS) use. AIMS AND METHODS: U.S nationally representative data from adults in the Population Assessment of Tobacco and Health (PATH) Study (2013/14-2021, Waves 1-6) who smoked cigarettes in the past 30 days (P30D) were analyzed (n = 13 640). The exposure was P30D ENDS use. The outcome was P30D cigarette discontinuation at biennial follow-up. Weighted trend analyses were conducted to test for differences in cigarette discontinuation trends by ENDS use. RESULTS: Between 2013/14 and 2015/16, cigarette discontinuation rates were both 16% for those who used ENDS and for those who did not; between 2018/19 and 2021, rates were ~30% for those who used ENDS and ~20% for those who did not; the time by ENDS use interaction was significant. CONCLUSIONS: The relationship between adults' ENDS use and cigarette discontinuation in the context of an expanded ENDS marketplace, new tobacco regulatory actions, and COVID-19 differs from the relationship in earlier years. IMPLICATIONS: It is important for public health decisions to be informed by research based on the contemporary ENDS marketplace and circumstances.

Systemic biomarkers of exposure associated with ENDS use: a scoping review.

OBJECTIVE: This scoping review provides an overview of the existing literature on biomarkers of exposure from electronic nicotine delivery systems (ENDS) use and identifies gaps in existing knowledge. DATA SOURCES: We searched two international databases (PubMed and Web of Science) to identify relevant studies published from August 2013 to February 2021. DATA SELECTION: Studies were included if they assessed and compared biomarkers of exposure between exclusive ENDS users, non-users, exclusive cigarette smokers, dual users of ENDS and cigarettes or cigarette smokers who switch to ENDS. DATA EXTRACTION AND SYNTHESIS: Of the 5074 studies identified, 188 studies met criteria and were selected for full-text screening. Of these, 27 studies were selected for inclusion and data extraction. CONCLUSIONS: Consistent, although limited, evidence shows that exclusive ENDS users have elevated levels of biomarkers of certain volatile organic compounds (VOCs; eg, acrylamide and acrylonitrile), metals (eg, cadmium and selenium) and propylene glycol compared with non-users; however, evidence for biomarkers of other toxicants (eg, acrolein, benzene and chromium) is mixed. Biomarkers of most VOCs are lower in ENDS users compared with cigarette smokers, and cigarette smokers who switch to ENDS consistently show reductions in VOC biomarkers. Evidence comparing metal exposures from exclusive ENDS use, cigarette smoking and dual use is mixed and depends on the metal. ENDS and e-liquid characteristics as well as use patterns may be associated with elevated exposure to VOCs and metals. Additional rigorous, controlled studies can assess biomarker exposures from ENDS use and inform the overall risk-benefit of ENDS use for different user populations.

Exploring the potential neurotoxicity of vaping vitamin E or vitamin E acetate.

Serious adverse health effects have been reported with the use of vaping products, including neurologic disorders and e-cigarette or vaping product use-associated lung injury (EVALI). Vitamin E acetate, likely added as a diluent to cannabis-containing products, was linked to EVALI. Literature searches were performed on vitamin E and vitamin E acetate-associated neurotoxicity. Blood brain barrier (BBB) penetration potential of vitamin E and vitamin E acetate were evaluated using cheminformatic techniques. Review of the literature showed that the neurotoxic potential of inhalation exposures to these compounds in humans is unknown. Physico-chemical properties demonstrate these compounds are lipophilic, and molecular weights indicate vitamin E and vitamin E acetate have the potential for BBB permeability. Computational models also predict both compounds may cross the BBB via passive diffusion. Based on literature search, no experimental nonclinical studies and clinical information on the neurotoxic potential of vitamin E via inhalation. Neurotoxic effects from pyrolysis by-product, phenyl acetate, structurally analogous to vitamin E acetate, suggests vitamin E acetate has potential for central nervous system (CNS) impairment. Cheminformatic model predictions provide a theoretical basis for potential CNS permeability of these inhaled dietary ingredients suggesting prioritization to evaluate for potential hazard to the CNS.

Immunohistochemistry Improves the Detection of Adenovirus in Gastrointestinal Biopsy Specimens From Hematopoietic Stem Cell Transplant Recipients.

OBJECTIVES: Gastrointestinal infections by cytomegalovirus (CMV) and adenovirus may complicate hematopoietic stem cell transplantation (HSCT). Although CMV and adenovirus produce recognizable cytopathic changes, these changes may be subtle or focal. The value of viral immunohistochemistry in detecting infection in HSCT recipients when cytopathic changes are not identified has not been demonstrated. METHODS: H&E-stained sections from gastrointestinal biopsy specimens were reviewed by three pathologists. Cases were classified as negative, suspicious, or positive for CMV and/or adenovirus infection based on the presence or absence of viral inclusions. Viral immunohistochemistry was performed, and the results were compared with the interpretations of H&E-stained sections. RESULTS: Four of 104 cases contained viral inclusions confirmed by immunohistochemistry: two were infected with CMV, and two were positive for adenovirus. All three reviewers correctly classified both immunopositive CMV cases on H&E evaluation. However, all reviewers missed the diagnosis of adenovirus on H&E assessment in one case. CONCLUSIONS: In HSCT recipients, cytopathic changes of adenovirus may be easily missed in H&E-stained sections of gastrointestinal biopsy specimens. Thus, the routine use of adenovirus immunohistochemistry in all cases is recommended. Both cases of CMV infection were apparent on H&E evaluation, so the judicious use of immunohistochemical stains for CMV in selected cases may be considered.

Idelalisib-associated Colitis: Histologic Findings in 14 Patients.

Idelalisib is an inhibitor of the PI3Kδ isoform approved for treatment of patients with relapsed chronic lymphocytic leukemia and indolent non-Hodgkin lymphoma. Many patients develop gastrointestinal symptoms during idelalisib therapy; however, the pathologic effects of this drug have not been characterized. We identified 50 patients who received at least 3 months of idelalisib therapy. Clinical findings and symptoms were noted for each patient, and endoscopic findings were recorded for those who underwent colonoscopic examination. Hematoxylin and eosin-stained sections from colonic biopsy samples were evaluated for histologic patterns of injury. Twenty-three (46%) patients experienced diarrhea during treatment with idelalisib, including 8 with severe symptoms (≥7 stools/d above baseline and/or requiring hospitalization). Fourteen patients underwent colonoscopic examination with mucosal biopsy. Twelve (86%) of these had colitis characterized by intraepithelial lymphocytosis, crypt cell apoptosis, and neutrophilic infiltration of crypt epithelium. Eleven patients had symptoms severe enough to warrant drug withdrawal, including 9 who were also treated with corticosteroids. Idelalisib commonly causes diarrheal symptoms in patients undergoing therapy for B-cell neoplasia, which may be severe in nearly 20% of patients. Characteristic histologic features include the combination of intraepithelial lymphocytosis and crypt cell apoptosis, often accompanied by neutrophils. Discontinuation of the drug results in symptomatic improvement and resolution of histologic changes.

Riedel thyroiditis: Fine needle aspiration findings of a rare entity.

Riedel thyroiditis is a rare fibrosing disorder characterized by extension of the fibroinflammatory process beyond the thyroid capsule. Due to the nature of this lesion, fine-needle aspiration often yields scant material and may be interpreted as non-diagnostic. In this report, we describe cytologic features that allow the cytopathologist to favor a diagnosis of Riedel thyroiditis, thereby guiding appropriate further work-up and management.