Neutrophils Expressing Programmed Death-Ligand 1 Play an Indispensable Role in Effective Bacterial Elimination and Resolving Inflammation in Methicillin-Resistant Staphylococcus aureus Infection.

Programmed death ligand 1 (PD-L1) is a co-inhibitory molecule expressed on the surface of various cell types and known for its suppressive effect on T cells through its interaction with PD-1. Neutrophils also express PD-L1, and its expression is elevated in specific situations; however, the immunobiological role of PD-L1+ neutrophils has not been fully characterized. Here, we report that PD-L1-expressing neutrophils increased in methicillin-resistant Staphylococcus aureus (MRSA) infection are highly functional in bacterial elimination and supporting inflammatory resolution. The frequency of PD-L1+ neutrophils was dramatically increased in MRSA-infected mice, and this population exhibited enhanced activity in bacterial elimination compared to PD-L1- neutrophils. The administration of PD-L1 monoclonal antibody did not impair PD-L1+ neutrophil function, suggesting that PD-L1 expression itself does not influence neutrophil activity. However, PD-1/PD-L1 blockade significantly delayed liver inflammation resolution in MRSA-infected mice, as indicated by their increased plasma alanine transaminase (ALT) levels and frequencies of inflammatory leukocytes in the liver, implying that neutrophil PD-L1 suppresses the inflammatory response of these cells during the acute phase of MRSA infection. Our results reveal that elevated PD-L1 expression can be a marker for the enhanced anti-bacterial function of neutrophils. Moreover, PD-L1+ neutrophils are an indispensable population attenuating inflammatory leukocyte activities, assisting in a smooth transition into the resolution phase in MRSA infection.

Doublet or Triplet Antiemetic Prophylaxis for Nausea and Vomiting Induced by Trastuzumab Deruxtecan: an Open-Label, Randomized, and Multicenter Exploratory Phase 2 Study.

Background: Trastuzumab deruxtecan is classified as an anticancer agent that poses a moderate emetic risk in the international guidelines for antiemetic therapy. The guidelines recommend emesis prophylaxis using a two-drug combination therapy comprising a 5-hydroxytryptamine-3 receptor antagonist (5-HT3RA) and dexamethasone (DEX). However, the high incidence of nausea and vomiting associated with trastuzumab deruxtecan is problematic. The National Comprehensive Cancer Network guideline version 1.2023 classified trastuzumab deruxtecan as having a high risk of emesis and changed its recommendation to a triplet regimen including a neurokinin-1 receptor antagonist (NK1RA). However, the emetogenic potential of trastuzumab-deruxtecan and the optimal antiemetic prophylaxis are controversial. Hence, this exploratory phase 2 study aimed to assess the efficacy and safety of treatment comprising 5-HT3RA and DEX with or without a NK1RA in preventing trastuzumab deruxtecan-induced nausea and vomiting. Methods: We conducted an open-label and randomized exploratory phase 2 study at 14 centers in Japan. Patients with breast cancer who were scheduled to receive trastuzumab deruxtecan were enrolled in this study. The patients were randomly assigned to receive granisetron and DEX (arm GD) or granisetron, DEX, and aprepitant (fosaprepitant; arm GDA). The primary endpoint was complete response (CR; no emesis or no rescue therapy) during the overall phase (120 h after the start of trastuzumab deruxtecan). Results: Between September 2020 and March 2023, 40 patients were randomly assigned to the GD (n = 19) or GDA (n = 21) arm. In the GDA arm, one patient who did not complete the use of the rescue medication listed in the diary was excluded from the efficacy analysis, which included the use of rescue medication. The CR rates during the overall phase were 36.8% and 70.0% in the GD and GDA arms, respectively (odds ratio 0.1334; 95% confidence interval [CI]: 0.0232-0.7672; P = 0.0190), with a difference of 33.2%. No grade 3 or 4 toxicity related to antiemetic therapy was observed. Conclusions: Patients receiving trastuzumab deruxtecan require triple therapy, including mandatory NK1RA administration.

Local recurrence of breast cancer histologically resembling Paget disease presumably due to needle tract seeding: a case report.

Seeding of cancer cells along the needle tract during core needle biopsy is a well-known phenomenon, with a reported frequency of between 22 and 50% [Hoorntje et al. in Eur J Surg Oncol 30:520-525, 2004;Liebens et al. in Maturitas 62:113-123, 2009;Diaz et al. in AJR Am J Roentgenol 173:1303-1313, 1999;]. Local recurrence due to needle tract seeding is rare because the immune system eliminates the cancer cells in most cases. In addition, most local recurrences due to needle tract seeding occur as invasive carcinoma after diagnosis of invasive ductal carcinoma of the breast or mucinous carcinoma, and needle tract seeding due to noninvasive carcinoma is uncommon. We herein report a rare case of local breast cancer recurrence histologically resembling Paget disease, presumably due to needle tract seeding after core needle biopsy for diagnosis of ductal carcinoma in situ of the breast. After receiving a diagnosis of ductal carcinoma in situ, the patient underwent skin-sparing mastectomy and breast reconstruction with a latissimus dorsi musculocutaneous flap. The pathological study showed ER/PgR-negative ductal carcinoma in situ, and no postoperative radiation therapy or systemic therapy was administered. Six months after the surgery, the patient had a breast cancer recurrence histologically resembling Paget disease, presumably in the scar of her core needle biopsy. The pathological study showed Paget disease localized in the epidermis, no invasive carcinoma, and no lymph node metastasis. It was morphologically similar to the primary lesion and was diagnosed as a local recurrence due to needle tract seeding.

Absolute Lymphocyte Count as an Independent Prognostic Factor in Metastatic Breast Cancer: A Retrospective Study.

INTRODUCTION: Recently, absolute lymphocyte count (ALC) and neutrophil-to-lymphocyte ratio (NLR) have been reported to be prognostic and/or predictive factors in breast cancer. However, most of the investigations on the relationship between systemic inflammatory markers and prognosis have been conducted perioperatively, with few studies reporting on patients with metastatic or recurrent breast cancer (MBC). Here, we investigated the role of ALC and NLR as prognostic factors of MBC. METHODS: This was a retrospective observational study of patients with MBC treated at the University of Tsukuba Hospital between 2013 and 2020. ALC and NLR clinical data were obtained from the patients' charts. Based on the previous reports, the cutoff value of ALC was set at 1,500/µL and that of NLR, at 3. We investigated the prognostic significance of ALC and NLR. RESULTS: About 80% of the 243 included patients were hormone receptor-positive, 20% were HER2-positive, and 10% were triple negative. The patients were grouped as follows: 114 (46.9%) and 129 (53.1%) in the high and low ALC groups and 145 (59.7%) and 98 (40.3%) in the high and low NLR groups, respectively. The group with high ALC at diagnosis of MBC showed significantly better prognosis (p = 0.002), and the median overall survival (OS) was 70.9 months, as compared with 40.2 months for the low ALC group. On multivariate analysis, visceral metastasis, subtype, and ALC were independent variables for OS; the NLR status was not correlated with OS. CONCLUSIONS: Analysis of real-world data suggests that ALC at diagnosis of MBC is an independent prognostic factor.

Long-Term Fluorescent Tissue Marking Using Tissue-Adhesive Porphyrin with Polycations Consisting of Quaternary Ammonium Salt Groups.

Localization of tumors during laparoscopic surgery is generally performed by locally injecting India ink into the submucosal layer of the gastrointestinal tract using endoscopy. However, the location of the tumor is obscured because of the black-stained surgical field and the blurring caused by India ink. To solve this problem, in this study, we developed a tissue-adhesive porphyrin with polycations consisting of quaternary ammonium salt groups. To evaluate the ability of tissue-adhesive porphyrin in vivo, low-molecular-weight hematoporphyrin and tissue-adhesive porphyrin were injected into the anterior wall of the exposed stomach in rats. Local injection of low-molecular-weight hematoporphyrin into the anterior wall of the stomach was not visible even after 1 day because of its rapid diffusion. In contrast, the red fluorescence of the tissue-adhesive porphyrin was visible even after 7 days due to the electrostatic interactions between the positively-charged moieties of the polycation in the tissue-adhesive porphyrin and the negatively-charged molecules in the tissue. In addition, intraperitoneal injection of tissue-adhesive porphyrin in rats did not cause adverse effects such as weight loss, hepatic or renal dysfunction, or organ adhesion in the abdominal cavity. These results indicate that tissue-adhesive porphyrin is a promising fluorescent tissue-marking agent.

Elevated Production of Mitochondrial Reactive Oxygen Species via Hyperthermia Enhanced Cytotoxic Effect of Doxorubicin in Human Breast Cancer Cell Lines MDA-MB-453 and MCF-7.

Hyperthermia (HT) treatment is a noninvasive cancer therapy, often used with radiation therapy and chemotherapy. Compared with 37 °C, 42 °C is mild heat stress for cells and produces reactive oxygen species (ROS) from mitochondria. To involve subsequent intracellular accumulation of DOX, we have previously reported that the expression of ATP-binding cassette sub-family G member 2 (ABCG2), an exporter of doxorubicin (DOX), was suppressed by a larger amount of intracellular mitochondrial ROS. We then hypothesized that the additive effect of HT and chemotherapy would be induced by the downregulation of ABCG2 expression via intracellular ROS increase. We used human breast cancer cell lines, MCF-7 and MDA-MB-453, incubated at 37 °C or 42 °C for 1 h to clarify this hypothesis. Intracellular ROS production after HT was detected via electron spin resonance (ESR), and DOX cytotoxicity was calculated. Additionally, ABCG2 expression in whole cells was analyzed using Western blotting. We confirmed that the ESR signal peak with HT became higher than that without HT, indicating that the intracellular ROS level was increased by HT. ABCG2 expression was downregulated by HT, and cells were injured after DOX treatment. DOX cytotoxicity enhancement with HT was considered a result of ABCG2 expression downregulation via the increase of ROS production. HT increased intracellular ROS production and downregulated ABCG2 protein expression, leading to cell damage enhancement via DOX.

Exacerbation of prothrombin time-international normalized ratio before second polymyxin B cartridge hemoperfusion predicts poor outcome of patients with severe sepsis and/or septic shock.

BACKGROUND: Although polymyxin B cartridge hemoperfusion (PMX) has an important place in the treatment of patients with severe sepsis and/or septic shock (SS), there are few rigid indications for performing PMX a second time.The objective of the study was to investigate the clinicolaboratory characteristics (CCs) showing the most significant change from the first to the second PMX and associated with 28-d mortality in patients with SS. METHODS: Between April 2006 and March 2008, 78 patients with SS who had received two sessions of PMX in a prospectively collected multicenter collaboration study were enrolled. Univariate and multivariate analyses using the differences in the values of individual CCs (Δ-CCs) were performed to assess the CCs showing the most significant change in value associated with 28-d mortality. The Δ-CC was defined as: Δ2nd-1st-CC = value of the CC just before the second PMX - value of the CC just before the first PMX. RESULTS: Among 28 Δ2nd-1st-CCs, 10 Δ2nd-1st-CCs were selected by using receiver operating characteristic (ROC) curve analyses. The results of multivariate analysis using adequate 8 Δ2nd-1st-CCs that had been selected by univariate analyses revealed that only Δ2nd-1st-prothrombin time-international normalized ratio (PT-INR) (≤0.16/>0.16; hazard ratio = 6.562; 95% CI = 1.525-28.23; P = 0.012) was associated with 28-d mortality. Survival curve analysis demonstrated a significant difference in 28-d mortality between patients with a lower (≤0.16) and a higher (>0.16) Δ2nd-1st-PT-INR (P < 0.001). CONCLUSIONS: Patients with exacerbation of PT-INR (>0.16) after initial PMX are unlikely to benefit clinically from a second PMX for treatment of SS.