Prognostic significance of peripheral consolidations at chest x-ray in severe COVID-19 pneumonia.

To evaluate the possible prognostic significance of the development of peripheral consolidations at chest x-ray in COVID-19 pneumonia, we retrospectively studied 92 patients with severe respiratory failure (PaO2/FiO2 ratio < 200 mmHg) that underwent at least two chest x-ray examinations (baseline and within 10 days of admission). Patients were divided in two groups based on the evolution of chest x-ray toward the appearance of peripheral consolidations or toward a greater extension of the lung abnormalities but without peripheral consolidations. Patients who developed lung abnormalities without peripheral consolidations as well as patients who developed peripheral consolidations showed, at follow-up, a significant worsening of the PaO2/FiO2 ratio but a significantly lower mortality and intubation rate was observed in patients with peripheral consolidations at chest x-ray. The progression of chest x-ray toward peripheral consolidations is an independent prognostic factor associated with lower intubation rate and mortality.

Expansion of memory Vδ2 T cells following SARS-CoV-2 vaccination revealed by temporal single-cell transcriptomics.

γδ T cells provide rapid cellular immunity against pathogens. Here, we conducted matched single-cell RNA-sequencing and γδ-TCR-sequencing to delineate the molecular changes in γδ T cells during a longitudinal study following mRNA SARS-CoV-2 vaccination. While the first dose of vaccine primes Vδ2 T cells, it is the second administration that significantly boosts their immune response. Specifically, the second vaccination uncovers memory features of Vδ2 T cells, shaped by the induction of AP-1 family transcription factors and characterized by a convergent central memory signature, clonal expansion, and an enhanced effector potential. This temporally distinct effector response of Vδ2 T cells was also confirmed in vitro upon stimulation with SARS-CoV-2 spike-peptides. Indeed, the second challenge triggers a significantly higher production of IFNγ by Vδ2 T cells. Collectively, our findings suggest that mRNA SARS-CoV-2 vaccination might benefit from the establishment of long-lasting central memory Vδ2 T cells to confer protection against SARS-CoV-2 infection.

Transcriptomic profile of TNFhigh MAIT cells is linked to B cell response following SARS-CoV-2 vaccination.

Introduction: Higher frequencies of mucosal-associated invariant T (MAIT) cells were associated with an increased adaptive response to mRNA BNT162b2 SARS-CoV-2 vaccine, however, the mechanistic insights into this relationship are unknown. In the present study, we hypothesized that the TNF response of MAIT cells supports B cell activation following SARS-CoV-2 immunization. Methods: To investigate the effects of repeated SARS-CoV-2 vaccinations on the peripheral blood mononuclear cells (PBMCs), we performed a longitudinal single cell (sc)RNA-seq and scTCR-seq analysis of SARS-CoV-2 vaccinated healthy adults with two doses of the Pfizer-BioNTech BNT162b2 mRNA vaccine. Collection of PBMCs was performed 1 day before, 3 and 17 days after prime vaccination, and 3 days and 3 months following vaccine boost. Based on scRNA/TCR-seq data related to regulatory signals induced by the vaccine, we used computational approaches for the functional pathway enrichment analysis (Reactome), dynamics of the effector cell-polarization (RNA Velocity and CellRank), and cell-cell communication (NicheNet). Results: We identified MAIT cells as an important source of TNF across circulating lymphocytes in response to repeated SARS-CoV-2 BNT162b2 vaccination. The TNFhigh signature of MAIT cells was induced by the second administration of the vaccine. Notably, the increased TNF expression was associated with MAIT cell proliferation and efficient anti-SARS-CoV-2 antibody production. Finally, by decoding the ligand-receptor interactions and incorporating intracellular signaling, we predicted TNFhigh MAIT cell interplay with different B cell subsets. In specific, predicted TNF-mediated activation was selectively directed to conventional switched memory B cells, which are deputed to high-affinity long-term memory. Discussion: Overall, our results indicate that SARS-CoV-2 BNT162b2 vaccination influences MAIT cell frequencies and their transcriptional effector profile with the potential to promote B cell activation. This research also provides a blueprint for the promising use of MAIT cells as cellular adjuvants in mRNA-based vaccines.

Assessment of RT-PCR detection of human mammaglobin for the diagnosis of breast cancer derived pleural effusions.

The present study investigates the diagnostic significance of human mammaglobin (hMAM) mRNA expression in pleural effusions (PE) from breast cancer (BC) patients. Two hundred and fifty PE samples, including 32 from patients who had diagnosis of BC, 116 from patients with other cancers, and 102 from patients with benign diseases, were subjected to nested reverse-transcription polymerase chain reaction (RT-PCR) for hMAM, and the results were compared with conventional cytology. hMAM was found expressed in 76/250 (30.4%) total PE and in 23/28 (sensitivity of 82.1%) of the PE subgroup owing to metastasis from BC. The specificity for hMAM detection method was 75.7%, whereas accuracy, positive predictive value, and negative predictive value were 76.4%, 30.3%, and 97.1%, respectively. hMAM was also detected in 46/116 (39.6%) PE specimens from other types of cancer and in 7/102 (6.8%) from benign diseases. Comparative analysis of RT-PCR and cytology showed that 14 PE samples from metastatic BC (50%) were positive by both PCR and cytology, 9 (32.1%) were positive only by PCR and 5 (17.9%) were negative by both tests, whereas no cases were found of positive cytology with negative PCR. RT-PCR increased sensitivity of BC effusion detection to 32.1% (McNemar test, P=0.004). We demonstrated that RT-PCR for hMAM test was more sensitive than cytomorphology suggesting that, although hMAM is not BC specific, it may be useful in adjunct to cytology for the routine screening of malignant BC effusions.

Diagnosis and origin determination of malignant pleural effusions through the use of the breast cancer marker human mammaglobin.

As was reported that human mammaglobin (hMAM) may be expressed in malignant pleural effusions (PEs), we investigated the relevance of hMAM reverse-transcriptase polymerase chain reaction (RT-PCR) for their diagnosis and determination of primary origin. Two hundred and twenty-eight malignant (132 male, 96 female) and 185 benign (132 male, 53 female) PEs were investigated. Statistical analyses evaluated the diagnostic performance parameters in all PEs and in cytologically negative malignant PEs, the association between hMAM and benign or malignant status by the direct index of correlation [diagnostic odds ratio (DOR)], chi test, and P value (P). In addition, the discriminative diagnostic power of hMAM expression, independently in breast cancer, lung cancer (LC), malignant mesothelioma (MM), and other cancers was evaluated. In the entire patient population, hMAM was detected in 45.6% and 5.4% of malignant and benign PEs, respectively, in the male group in 41.7% and 4.5% and in the female group in 51.0% and 7.5% of malignant and benign PEs, respectively. A statistically significant correlation between hMAM and malignancy was found in the entire population (DOR=14.68, P<0.001) and in the male (DOR=15.00, P<0.001) or female (DOR=12.77, P<0.001) groups. hMAM RT-PCR increased the diagnostic rate of malignant PEs as it allowed us to detect as malignant 32.1% of cytologically negative PEs. In female patients the positivity of hMAM indicated with higher probability (50.8%) the origin of PEs from breast cancer but lower probability from LC (17%), MM (9.4%), or other cancers (15.1%), whereas in male patients it indicated with similar probability (about 40%) the origin from LC or MM. Our results suggest that hMAM RT-PCR may provide information both in the diagnosis of PE and in the search for the primary site of neoplasia, either in male or female patients.