George Vartholomatos

The accurate assessment of malignancy and the precise characterization of cancer type are pivotal in guiding clinical decisions and ensuring optimal patient outcomes. The challenging task of identifying the primary site of carcinoma, especially during a surgical procedure, is not always possible and necessitates the exploration of novel, innovative diagnostic techniques. In this report, we detail a unique case of carcinoma of unknown primary origin encountered during an orthopedic surgical procedure. We introduce a novel intraoperative flow cytometry (iFC) methodology, distinctly different from traditional flow cytometry, which is tailored for real-time assessment during surgeries. This iFC technique, applied in a bone metastasis case of unknown primary origin, enabled DNA content analysis and the quantification of cytokeratin for rapid malignancy characterization, presenting an avenue for immediate surgical guidance and decision making. The case was distinctively characterized using iFC, shedding light on the potential of this emerging technique. iFC has been gaining traction because of its ability to facilitate cancer cell assessment and margin evaluation. It has been successfully applied across a wide spectrum of neoplastic conditions. Our innovative, two-step approach using iFC encompasses (1) DNA content analysis, which serves as a reliable indicator for the detection of cancer cells, and (2) the quantification of cytokeratin, a pivotal marker, which aids in the characterization and classification of a malignancy. In this case, the malignancy was classified as a carcinoma. The findings obtained from iFC were subsequently validated through pathology assessment, confirming the accuracy and reliability of our approach. This noteworthy case strengthens the potential of iFC as a novel tool in malignancy assessment, which is not just limited to cell cycle analysis but instead extends beyond this application. The promising results obtained from this case study serve as a testament to the need for more extensive research in clinical studies.

Background: Dysregulation of the immune response in the course of COVID-19 has been implicated in critical outcomes. Lymphopenia is evident in severe cases and has been associated with worse outcomes since the early phases of the pandemic. In addition, cytokine storm has been associated with excessive lung injury and concomitant respiratory failure. However, it has also been hypothesized that specific lymphocyte subpopulations (CD4 and CD8 T cells, B cells, and NK cells) may serve as prognostic markers for disease severity. The aim of this study was to investigate possible associations of lymphocyte subpopulations alterations with markers of disease severity and outcomes in patients hospitalized with COVID-19. Materials/Methods: A total of 42 adult hospitalized patients were included in this study, from June to July 2021. Flow-cytometry was used to calculate specific lymphocyte subpopulations on day 1 (admission) and on day 5 of hospitalization (CD45, CD3, CD3CD8, CD3CD4, CD3CD4CD8, CD19, CD16CD56, CD34RA, CD45RO). Markers of disease severity and outcomes included: burden of disease on CT (% of affected lung parenchyma injury), C-reactive protein and interleukin-6 levels. PO2/FiO2 ratio and differences in lymphocytes subsets between two timepoints were also calculated. Logistic and linear regressions were used for the analyses. All analyses were performed using Stata (version 13.1; Stata Corp, College Station, TX, USA). Results: Higher levels of CD16CD56 cells (Natural Killer cells) were associated with higher risk of lung injury (>50% of lung parenchyma). An increase in CD3CD4 and CD4RO cell count difference between day 5 and day 1 resulted in a decrease of CRP difference between these timepoints. On the other hand, CD45RARO difference was associated with an increase in the difference of CRP levels between the two timepoints. No other significant differences were found in the rest of the lymphocyte subpopulations. Conclusions: Despite a low patient number, this study showed that alterations in lymphocyte subpopulations are associated with COVID-19 severity markers. It was observed that an increase in lymphocytes (CD4 and transiently CD45RARO) resulted in lower CRP levels, perhaps leading to COVID-19 recovery and immune response homeostasis. However, these findings need further evaluation in larger scale trials.