Cancer treatment with immune checkpoint blockade (ICB) often induces immune-related adverse events (irAEs). We hypothesized that proteins coexpressed in tumors and normal cells could be antigenic targets in irAEs and herein described DITAS (discovery of tumor-associated self-antigens) for their identification. DITAS computed transcriptional similarity between lung tumors and healthy lung tissue based on single-sample gene set enrichment analysis. This identified 10 lung tissue–specific genes highly expressed in the lung tumors. Computational analysis was combined with functional T cell assays and single-cell RNA sequencing of the antigen-specific T cells to validate the lung tumor self-antigens. In patients with non–small cell lung cancer (NSCLC) treated with ICB, napsin A was a self-antigen that elicited strong CD8 ⁺ T cell responses, with ICB responders harboring higher frequencies of these CD8 ⁺ T cells compared with nonresponders. Human leukocyte antigen (HLA) class I ligands derived from napsin A were present in human lung tumors and in nontumor lung tissues, and napsin A tetramers confirmed the presence of napsin A–specific CD8 ⁺ T cells in blood and tumors of patients with NSCLC. Napsin A–specific T cell clonotypes were enriched in lung tumors and ICB-induced inflammatory lung lesions and could kill immortalized HLA-matched NSCLC cells ex vivo. Single-cell RNA sequencing revealed that these T cell clonotypes expressed proinflammatory cytokines and cytotoxic markers. Thus, DITAS successfully identified self-antigens, including napsin A, that likely mediate effective antitumor T cell responses in NSCLC and may simultaneously underpin lung irAEs.

Despite poor evidence, the antiparasitic ivermectin has been advocated as a potential COVID‐19 therapy. This has led to a rise in calls to poison‐control centers by people self‐medicating with ivermectin, which is sold over the counter for veterinary uses. We aimed to investigate the association between severe cutaneous adverse reactions (SCARs) and ivermectin. Postmarketing data from the FDA Adverse Event Reporting System (FAERS), gathered between 2014 and 2021, was employed to detect disproportional signals of SCARs following systemic ivermectin therapy. The reporting odds ratio (ROR) was used to quantify the strength of association, while adjusting for age, sex, and region. The search yielded 517 reports of systemic ivermectin (median age 54 years, 46.8% female), of which 25 (4.8%), 81 (15.7%), and 411 (79.5%) were classified as SCARs, nonsevere cutaneous adverse events (AEs), or noncutaneous AEs, respectively. The regional distribution differed between SCAR reports (32.0% from Africa and 12.0% from North America) compared with other AEs, which originated from North America in over half of cases. The most common SCARs were toxic epidermal necrolysis (seven cases), Stevens–Johnson syndrome (seven cases), and drug reaction with eosinophilia and systemic symptoms (four cases). Five SCAR cases (20.0%) resulted in death and 12 (48.0%) lead to hospitalization. There was a strong safety signal for any SCAR (adjusted ROR 3.34, 95% confidence interval [CI] 2.17–5.12) and toxidermias (adjusted ROR 7.08, 95% CI 4.23–11.84). This study suggests that ivermectin is associated with SCARs on rare occasions. Dermatologists should be aware of this given the increase in ivermectin misuse.

Although a fourth dose of SARS-CoV-2 vaccine was shown to be effective, the immunogenicity of a fifth dose in immunocompetent individuals had not been well described. This was a prospective observational cohort study of previously vaccinated healthcare workers at a single tertiary hospital in Israel. Individuals were administered up to three booster doses of the BNT162b2 mRNA vaccine (i.e., up to five overall doses), during the period between July 2021 and January 2023. Immunogenicity was assessed using the SARS-CoV-2 IgG (sCOVG) semi-quantitative assay, performed at several time points. The cohort consisted of 162 individuals (median age 69 years, 62% female). Of these, 104 (64%) received four doses and 58 (36%) received five doses. Anti-SARS-CoV-2 antibody levels increased in all cases, regardless of the baseline levels. The fold-change increase in the mean sCOVG index was 29.2 (SD 2.6) after the third vaccine, 3.8 (SD 2.4) after the fourth vaccine, and 3.6 (SD 3.0) after the fifth vaccine. A waning effect over time was seen in 78% and 43% of participants for the third and fourth doses, respectively. Adverse events following the fifth dose were limited and mild. Similar to previous booster vaccines, a fifth dose of BNT162b2 is immunogenic and safe in healthy individuals, although the clinical implications remain unclear.

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