APMIS

doi: 10.1111/apm.13151pmid: N/A

Mousavi, Nabi; Truelsen, Sarah Line Bring; Bernth‐Andersen, Simon; Koch, Anders; Heegaard, Steffen

doi: 10.1111/apm.13254pmid: 35655437

KRAS mutation is one of the most frequent driver mutations in colorectal cancer (CRC) and is also a prognostic biomarker. The aim of the present study was to determine the frequency of KRAS mutations over time in the Greenlandic population diagnosed with CRC. In total, 578 patients with the diagnosis of adenocarcinoma between 1988 and 2017 were identified. The status of KRAS and the mutational subtypes of KRAS mutations were determined in 102 representative samples by the Idylla™ platform in the time periods 1988–1990, 2002–2004, and 2015–2017. The results showed that the frequency of the KRAS mutations increased significantly, from 27% in 1988–1990 to 43% in 2015–2017 (p < 0.001). Furthermore, the most frequent subtypes of KRAS mutations in Greenland were G12D (c.35G > A) with 14%, G12V (c.35G > T) with 7%, and G13D (c.38G > A) with 6%. In conclusion, this study showed that the frequency of KRAS mutations in CRC has been increasing in recent decades in the specific population of Greenland. The results of this study may be used in initiatives related to targeted therapy of CRC in specific ethnicities and in investigations focusing on the environmental factors of cancer‐related somatic mutations.

Grantzau, Trine; Toft, Birgitte Grønkær; Melchior, Linea Cecilie; Elversang, Johanna; Stormoen, Dag Rune; Omland, Lise Høj; Pappot, Helle

doi: 10.1111/apm.13249pmid: 35616216

Checkpoint inhibitors have changed the treatment landscape of advanced urothelial carcinoma (mUC), and recently, a fibroblast‐growth‐factor‐receptor (FGFR) inhibitor has been introduced. This study aimed at estimating programmed death‐ligand 1 (PD‐L1) expression in primary tumors (PTs) and the PD‐L1 expression concordance between PTs and paired metastases in 100 patients with UC managed in the real‐world setting. Further, the aim was to investigate FGFR1–3 aberrations and the correlation between FGFR1–3 aberrations and PD‐L1 expression. PD‐L1 immunohistochemistry was performed on 100 formalin‐fixed paraffin‐embedded archival primary UC samples and 55 matched metastases using the 22C3 PD‐L1 assay. PD‐L1 expression was determined by the combined positive score, considered positive at ≥10. Targeted next‐generation sequencing on the S5+/Prime System with the Oncomine Comprehensive Assay version 3 was used to detect FGFR1‐3 aberrations in PTs. We found that 29 of 100 PTs had positive PD‐L1 expression. The PD‐L1 concordance rate was 71%. FGFR1‐3 aberrations were observed in 18% of PTs, most frequently FGFR3 amplifications or mutations. We found no association between FGFR1‐3 aberrations and PT PD‐L1 expression (p = 0.379). Our data emphasize the need for further studies in predictive biomarkers.

Kolpen, Mette; Dalby Sørensen, Christian; Faurholt‐Jepsen, Daniel; Hertz, Frederik Boëtius; Jensen, Peter Østrup; Bestle, Morten Heiberg

doi: 10.1111/apm.13224pmid: 35349738

The aim of this study was to assess L‐lactate and D‐lactate in endotracheal aspirate from intubated patients hospitalized at the intensive care unit and explore their use as diagnostic biomarkers for inflammation and lower respiratory tract infections (LRTI). Tracheal aspirates from 91 intubated patients were obtained at time of intubation and sent for microbiological analyses, neutrophil count, and colorimetric lactate measurements. We compared the concentration of lactate from patients with microbiological verified LRTI or clinical/radiological suspicion of LRTI with a control group. In addition, associations between inflammation and the lactate isomers were examined by correlating L‐lactate and D‐lactate with sputum neutrophils and clinical assessments. The concentration of L‐lactate was increased in aspirates with verified or suspected LRTI (p < 0.001) relative to the control group at Day 0. Connections between L‐lactate and inflammation were indicated by the correlation between neutrophils and L‐lactate (p < 0.001). We found no increase in sputum D‐lactate from patients with verified or suspected LRTI relative to the control group and D‐lactate was not correlated with neutrophils. L‐lactate was found to be a potential indicator for inflammation and LRTI at the time of intubation. An association was found between neutrophil count and L‐lactate. Interestingly, the increase of L‐lactate in the control group after intubation may suggest that intubation challenges the host response by inflicting tissue damage or by introducing infectious microbes.

Schwartz, Franziska A.; Nielsen, Luna; Struve Andersen, Jessica; Bock, Magnus; Christophersen, Lars; Sunnerhagen, Torgny; Lerche, Christian Johann; Bay, Lene; Bundgaard, Henning; Høiby, Niels; Moser, Claus

doi: 10.1111/apm.13231pmid: 35460117

Infective endocarditis (IE) is a serious infection of the inner surface of heart, resulting from minor lesions in the endocardium. The damage induces a healing reaction, which leads to recruitment of fibrin and immune cells. This sterile healing vegetation can be colonized during temporary bacteremia, inducing IE. We have previously established a novel in vitro IE model using a simulated IE vegetation (IEV) model produced from whole venous blood, on which we achieved stable bacterial colonization after 24 h. The bacteria were organized in biofilm aggregates and displayed increased tolerance toward antibiotics. In this current study, we aimed at further characterizing the time course of biofilm formation and the impact on antibiotic tolerance development. We found that a Staphylococcus aureus reference strain, as well as three clinical IE isolates formed biofilms on the IEV after 6 h. When treatment was initiated immediately after infection, the antibiotic effect was significantly higher than when treatment was started after the biofilm was allowed to mature. We could follow the biofilm development microscopically by visualizing growing bacterial aggregates on the IEV. The findings indicate that mature, antibiotic‐tolerant biofilms can be formed in our model already after 6 h, accelerating the screening for optimal treatment strategies for IE.

Fritz, Blaine G.; Kirkegaard, Julius B.; Nielsen, Claus Henrik; Kirketerp‐Møller, Klaus; Malone, Matthew; Bjarnsholt, Thomas

doi: 10.1111/apm.13234pmid: 35567538

Clinicians and researchers utilize subjective, clinical classification systems to stratify lower extremity ulcer infections for treatment and research. The purpose of this study was to examine whether these clinical classifications are reflected in the ulcer's transcriptome. RNA sequencing (RNA‐seq) was performed on biopsies from clinically infected lower extremity ulcers (n = 44). Resulting sequences were aligned to the host reference genome to create a transcriptome profile. Differential gene expression analysis and gene ontology (GO) enrichment analysis were performed between ulcer severities as well as between sample groups identified by k‐means clustering. Lastly, a support vector classifier was trained to estimate clinical infection score or k‐means cluster based on a subset of genes. Clinical infection severity did not explain the major sources of variability among the samples and samples with the same clinical classification demonstrated high inter‐sample variability. High proportions of bacterial RNA were identified in some samples, which resulted in a strong effect on transcription and increased expression of genes associated with immune response and inflammation. K‐means clustering identified two clusters of samples, one of which contained all of the samples with high levels of bacterial RNA. A support vector classifier identified a fingerprint of 20 genes, including immune‐associated genes such as CXCL8, GADD45B, and HILPDA, which accurately identified samples with signs of infection via cross‐validation. This study identified a unique, host‐transcriptome signature in the presence of infecting bacteria, often incongruent with clinical infection‐severity classifications. This suggests that stratification of infection status based on a transcriptomic fingerprint may be useful as an objective classification method to classify infection severity, as well as a tool for studying host–pathogen interactions.

Jensen, Peter Østrup; Nielsen, Bibi Uhre; Kolpen, Mette; Pressler, Tacjana; Faurholt‐Jepsen, Daniel; Mathiesen, Inger Hee Mabuza

doi: 10.1111/apm.13233pmid: 35635299

Blood glucose levels exceeding 8 mM are shown to increase glucose levels in airway surface in cystic fibrosis (CF). Moreover, high levels of endobronchial glucose are proposed to increase the growth of common CF bacteria and feed the neutrophil‐driven inflammation. In the infected airways, glucose may be metabolized by glycolysis to lactate by both bacteria and neutrophils. Therefore, we aimed to investigate whether increased blood glucose may fuel the glycolytic pathways of the lung inflammation by determining sputum glucose and lactate during an oral glucose tolerance test (OGTT). Sputum from 27 CF patients was collected during an OGTT. Sputum was collected at fasting and one and two hours following the intake of 75 g of glucose. Only participants able to expectorate more than one sputum sample were included. Glucose levels in venous blood and lactate and glucose content in sputum were analyzed using a regular blood gas analyzer. We collected 62 sputum samples: 20 at baseline, 22 after 1 h, and 20 after 2 h. Lactate and glucose were detectable in 30 (48.4%) and 43 (69.4%) sputum samples, respectively. The sputum lactate increased significantly at 2 h in the OGTT (p = 0.024), but sputum glucose was not changed. As expected, plasma glucose level significantly increased during the OGTT (p < 0.001). In CF patients, sputum lactate increased during an OGTT, while the sputum glucose did not reflect the increased plasma glucose. The increase in sputum lactate suggests that glucose spills over from plasma to sputum where glucose may enhance the inflammation by fueling the anaerobic metabolism in neutrophils or bacteria.

Duployez, Claire; Wallet, Frédéric; Pflimlin, Arnaud; Leguy, Diane; Vachée, Anne; Loïez, Caroline

doi: 10.1111/apm.13250pmid: 35620960

Capnocytophaga canimorsus is a Gram‐negative rod commensal of oral cavity of dogs and cats. It can cause sepsis, septic shock, endocarditis, and meningitis associated with bites or licking wounds, especially in immunocompromised patients. Herein, we report a case of C. canimorsus spondylodiscitis linked to a dog bite in a previously healthy patient and review the literature on this pathogen.