Single-cell Raman microscopy with machine learning highlights distinct biochemical features of neutrophil extracellular traps and necrosis.

The defining biology that distinguishes neutrophil extracellular traps (NETs) from other forms of cell death is unresolved, and techniques which unambiguously identify NETs remain elusive. Raman scattering measurement provides a holistic overview of cell molecular composition based on characteristic bond vibrations in components such as lipids and proteins. We collected Raman spectra from NETs and freeze/thaw necrotic cells using a custom built high-throughput platform which is able to rapidly measure spectra from single cells. Principal component analysis of Raman spectra from NETs clearly distinguished them from necrotic cells despite their similar morphology, demonstrating their fundamental molecular differences. In contrast, classical techniques used for NET analysis, immunofluorescence microscopy, extracellular DNA, and ELISA, could not differentiate these cells. Additionally, machine learning analysis of Raman spectra indicated subtle differences in lipopolysaccharide (LPS)-induced as opposed to phorbol myristate acetate (PMA)-induced NETs, demonstrating the molecular composition of NETs varies depending on the stimulant used. This study demonstrates the benefits of Raman microscopy in discriminating NETs from other types of cell death and by their pathway of induction.

Persistence of SARS-CoV-2 neutralizing antibodies and anti-Omicron IgG induced by BNT162b2 mRNA vaccine in patients with autoimmune inflammatory rheumatic disease: an explanatory study in Japan.

Background: Autoimmune inflammatory rheumatic disease (AIRD) patients are at high risk of the coronavirus disease 2019 (COVID-19), but the medium-term effects of immunosuppressants on vaccine efficacy are unknown. We investigated the duration of humoral responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wild-type and Omicron variant in AIRD patients administered with two doses of the BNT162b2 (Pfizer-BioNTech) vaccine. Methods: Serum-neutralizing antibody (NAb) and anti-receptor-binding domain (RBD)/spike antibody levels were measured. Short- and medium-term effects of immunosuppressants were analyzed pre-vaccination (Term 1) and 14-42 days (Term 2) and 100-200 days (Term 3) after the second vaccination. Findings: From Feb 1, 2021, to Feb 28, 2022, 439 AIRD patients and 146 healthy controls were investigated. The seropositivity rate and log10-NAb titers were significantly lower in AIRD patients than in controls at Terms 2 and 3. In rheumatoid arthritis patients, tumor necrosis factor-α inhibitors (TNFis) at Term 3, and older age, glucocorticoids, and abatacept at Terms 2 and 3 were risk factors for reduced responses. Anti-Omicron RBD/spike IgG levels strongly correlated with NAb titers. Interpretation: Glucocorticoids, TNFis, and abatacept treatments negatively affect the longevity of humoral responses to SARS-CoV-2, including Omicron, after two vaccine doses. These findings may inform the timing of additional vaccination for AIRD patients. Funding: Cloud Funding of Peace Winds Japan; Center of Innovation Program from the Ministry of Education, Culture, Sports, Science and Technology of Japan; Japan Society for the Promotion of Science KAKENHI; Japan Agency for Medical Research and Development; Kansai Economic Federation; Mitsubishi Zaidan; and Research Grant from Japan Agency for Medical Research and Development-Core Research for Evolutional Science and Technology.

Consecutive BNT162b2 mRNA vaccination induces short-term epigenetic memory in innate immune cells.

Consecutive mRNA vaccinations against SARS-CoV-2 reinforced both innate and adaptive immune responses. However, it remains unclear whether the enhanced innate immune responses are mediated by epigenetic regulation and, if so, whether these effects persist. Using mass cytometry, RNA-Seq, and ATAC-Seq, we show that BNT162b2 mRNA vaccination upregulated antiviral and IFN-stimulated gene expression in monocytes with greater effects after the second vaccination than those after the first vaccination. Transcription factor-binding motif analysis also revealed enriched IFN regulatory factors and PU.1 motifs in accessible chromatin regions. Importantly, although consecutive BNT162b2 mRNA vaccinations boosted innate immune responses and caused epigenetic changes in isolated monocytes, we show that these effects occurred only transiently and disappeared 4 weeks after the second vaccination. Furthermore, single-cell RNA-Seq analysis revealed that a similar gene signature was impaired in the monocytes of unvaccinated patients with COVID-19 with acute respiratory distress syndrome. These results reinforce the importance of the innate immune response in the determination of COVID-19 severity but indicate that, unlike adaptive immunity, innate immunity is not unexpectedly sustained even after consecutive vaccination. This study, which focuses on innate immune memory, may provide novel insights into the vaccine development against infectious diseases.

Refractory liver dysfunction was remarkably improved with chelating agents of Wilson's disease, in a patient with systemic lupus erythematosus-like syndrome after a parvovirus B19 infection.

Parvovirus B19 infection has been reported to be associated with systemic lupus erythematosus (SLE). Liver dysfunction is frequently observed in SLE patients. However, liver dysfunction caused by an aberrant copper metabolism is rarely seen in patients with parvovirus B19 infection. We report a rare case of SLE-like and Wilson's disease (WD) mimicking symptoms that were simultaneously triggered by parvovirus B19 infection. A 29-year-old man was admitted to our hospital with high-grade fever, arthralgia, and oral ulcers following a parvovirus B19 infection. Laboratory tests showed elevated transaminase levels, proteinuria, anti-double-stranded DNA antibody, high levels of serum ferritin, and leukocytopenia. He was suspected of having SLE with haemophagocytosis and was treated with high doses of prednisolone. Subsequently, the patient's arthritis symptoms improved and the proteinuria improved. Immunosuppressive therapies improved most of his symptoms except for the high titre of transaminases were alleviated. Laboratory findings indicated low serum levels of ceruloplasmin and copper along with elevated levels of 24-hour urinary copper. Liver biopsy detected copper in hepatocytes. Although the hepatic copper content was relatively low in this case, the dysregulation of copper metabolism was considered to be a main cause of his elevated levels of liver enzymes. Therefore, we started treatment with chelating agents used in WD treatment. At the 2-month follow-up, the liver dysfunction had significantly improved. Our case suggests that in patients with refractory liver dysfunction due to unknown reasons, it is necessary to exclude the possibility that an abnormal copper metabolism had caused an increase in the levels of liver enzymes.

Recovery from prolonged thrombocytopenia in patients with TAFRO syndrome: case series and literature review.

TAFRO syndrome is a newly proposed disease that is characterised by thrombocytopenia, anasarca, fever, reticulin fibrosis (or renal dysfunction), and organomegaly. Generally, high doses of corticosteroids are recommended for the initial treatment of TAFRO syndrome; however, some patients experience prolonged refractory thrombocytopenia after initiating such therapies. If corticosteroid treatment alone is ineffective, additional immunosuppressive therapies such as cyclosporine A are recommended. Since long-term use of immunosuppressive therapies with TAFRO syndrome sometimes causes serious infection, it is important to recognise the time to recovery from thrombocytopenia. In this study, we investigated how long it took to recover from thrombocytopenia, to aid clinicians in decision-making regarding the need to strengthen treatment for prolonged thrombocytopenia. Here, we describe three of our patients with TAFRO syndrome exhibiting prolonged thrombocytopenia. We also investigated the median period to recovery from this complication (defined as the time to increase the platelet count above 50,000/µL) after the initiation of high-dose corticosteroid treatment in our 3 cases and 38 peer-reviewed cases. We found that it took our patients 61 days to recover from thrombocytopenia; in comparison, our investigation of the 38 peer-reviewed case reports revealed a median recovery time of 47.5 days among previously reported patients. We showed the time to recovery from thrombocytopenia in patients with TAFRO syndrome for the first time. Our findings ought to be useful for decision-making among clinicians regarding the administration of other immunosuppressive treatments in addition to corticosteroid.