Ultra-sensitive CTC-based liquid biopsy for pancreatic cancer enabled by large blood volume analysis

The limited sensitivity of circulating tumor cell (CTC) detection in pancreatic adenocarcinoma (PDAC) stems from their extremely low concentration in the whole circulating blood, necessitating enhanced detection methodologies. This study sought to amplify assay-sensitivity by employing diagnostic leukapheresis (DLA) to screen large blood volumes. Sixty patients were subjected to DLA, with a median processed blood volume of ~ 2.8 L and approximately 5% of the resulting DLA-product analyzed using CellSearch (CS). Notably, DLA significantly increased CS-CTC detection to 44% in M0-patients and 74% in M1-patients, yielding a 60-fold increase in CS-CTC enumeration. DLA also provided sufficient CS-CTCs for genomic profiling, thereby delivering additional genomic information compared to tissue biopsy samples. DLA CS-CTCs exhibited a pronounced negative prognostic impact on overall survival (OS), evidenced by a reduction in OS from 28.6 to 8.5 months (univariate: p = 0.002; multivariable: p = 0.043). Additionally, a marked enhancement in sensitivity was achieved (by around 3-4-times) compared to peripheral blood (PB) samples, with positive predictive values for OS being preserved at around 90%. Prognostic relevance of CS-CTCs in PDAC was further validated in PB-samples from 228 PDAC patients, consolidating the established association between CTC-presence and reduced OS (8.5 vs. 19.0 months, p < 0.001). In conclusion, DLA-derived CS-CTCs may serve as a viable tool for identifying high-risk PDAC-patients and aiding the optimization of multimodal treatment strategies. Moreover, DLA enables comprehensive diagnostic profiling by providing ample CTC material, reinforcing its utility as a reliable liquid-biopsy approach. This high-volume liquid-biopsy strategy presents a potential pathway for enhancing clinical management in this malignancy.

Prognostic markers for the clinical course in the blood of patients with SARS-CoV-2 infection

BACKGROUND

The presentation of peptides and the subsequent immune response depend on the MHC characteristics and influence the specificity of the immune response. Several studies have found an association between HLA variants and differential COVID-19 outcomes and have shown that HLA genotypes are associated with differential immune responses against SARS-CoV-2, particularly in severely ill patients. Information, whether HLA haplotypes are associated with the severity or length of the disease in moderately diseased individuals is absent.

METHODS

Next-generation sequencing-based HLA typing was performed in 303 female and 231 male non-hospitalized North Rhine Westphalian patients infected with SARS-CoV2 during the first and second wave. For HLA-Class I, we obtained results from 528 patients, and for HLA-Class II from 531. In those patients, who became ill between March 2020 and January 2021, the 22 most common HLA-Class I (HLA-A, -B, -C) or HLA-Class II (HLA -DRB1/3/4, -DQA1, -DQB1) haplotypes were determined. The identified HLA haplotypes as well as the presence of a CCR5Δ32 mutation and number of O and A blood group alleles were associated to disease severity and duration of the disease.

RESULTS

The influence of the HLA haplotypes on disease severity and duration was more pronounced than the influence of age, sex, or ABO blood group. These associations were sex dependent. The presence of mutated CCR5 resulted in a longer recovery period in males.

CONCLUSION

The existence of certain HLA haplotypes is associated with more severe disease.

PCR-Based amplification of platelet mRNA sequences obtained from small-scale platelet samples

Platelet transcriptome studies provide a powerful tool in the analysis of disorders affecting the megakaryocytic-platelet lineage. However, individualised platelet gene expression profiling is hampered by the exceptionally low yield of platelet mRNA. The yield of mRNA transcripts that can be obtained from small-scale platelet preparations is generally not sufficient for standard RNA-labeling reactions used in expression profiling. Furthermore, leukocyte contaminants in platelet preparations are a potential source of 'unwanted' mRNA since they contain several orders of magnitude more mRNA than platelets. To overcome these limitations a strategy that combines leukocyte filtration and a PCR-based amplification technique (SMART) has been developed and extensively evaluated.

Recurrent intracardiac thrombosis as an unusual manifestation of inherited thrombophilia

Patients with inherited thrombophilia are at high risk for the development of venous thrombosis that manifests mainly as deep venous thrombosis of the legs and/or pulmonary embolism. We report spontaneous right-sided intracardiac thrombosis in a young man as an unusual manifestation of inherited thrombophilia. The diagnosis of thrombophilia was confirmed by demonstration of the prothrombin-G20210A-mutation in the homozygous state. A second spontaneous intracardiac thrombosis occurred 3 years after discontinuation of oral anticoagulant treatment. This indicates the high risk for recurrence in patients developing intracardiac thrombosis in the absence of an underlying cardiac disease and warrants long-term oral anticoagulant treatment.

Interleukin-1 beta upregulates tissue-type plasminogen activator in a keratinocyte cell line (HaCaT)

Human keratinocytes synthesize and secrete tissue-type plasminogen activator (tPA). tPA converts the inactive precursor enzyme plasminogen into the trypsin-like proteinase plasmin. tPA is not found in normal epidermis, but in lesional epidermis from patients with a variety of cutaneous diseases, including psoriasis, pemphigus and pemphigoid. The presence of tPA is probably a reaction to the disease process rather than the initiating event in these etiologically and histopathologically diverse lesions. However, the factor(s) that upregulate tPA expression and secretion in keratinocytes have remained largely elusive. We sought to determine whether the inflammatory cytokine interleukin-1 beta (IL-1 beta), which is commonly present in diverse epidermal lesions, influences tPA production. Accordingly, we studied the influence of IL-1 beta on secretion of tPA by cells of the human keratinocyte cell line HaCaT. We found that IL-1 beta increased tPA secretion in these cells. Given the observation that IL-1 beta is a common proinflammatory mediator in cutaneous diseases, our findings may explain the increase in tPA in clinically and etiologically diverse inflammatory epidermal lesions.

Upregulation of cell-surface-associated plasminogen activation in cultured keratinocytes by interleukin-1 beta and tumor necrosis factor-alpha

Keratinocytes synthesize and secrete urokinase-type plasminogen activator (uPA) which is bound in an autocrine manner to a specific receptor (uPA-R) at the keratinocyte surface. Plasminogen that is also bound to specific membrane binding sites is readily activated by uPA-R-bound uPA. Thus, plasmin is provided for proteolysis of pericellular glycoproteins. The expression of uPA and the uPA-R is confined to migrating keratinocytes during epidermal wound healing, rather than to keratinocytes of the normal epidermis. The regulatory factors of uPA/uPA-R expression in keratinocytes remained largely elusive. Proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) or interleukin-1 beta (IL-1 beta), are present in epidermal wounds. We have therefore tested IL-1 beta and TNF-alpha for their influence on surface-associated plasminogen activation in a human keratinocyte cell line (HaCaT) as well as in primary cultures of normal human epidermal keratinocytes. Both cytokines induced the secretion of uPA into the culture supernatants and a concomitant increase in uPA activity as well as in uPA and uPA-R antigen at the cell surface. The increase was preceded by an increase in specific mRNA. The induction was accompanied by an accelerated uPA-dependent and plasmin-mediated detachment of HaCaT cells from the culture substratum. Taken together, the proinflammatory cytokines IL-1 beta and TNF-alpha induced a coordinated increase in uPA and uPA-R as well as increased pericellular plasmin-mediated proteolysis in human epidermal keratinocytes. This function might be an element of the molecular cell biological events during epidermal wound healing.