111In-Pentetreotide Uptake Due to COVID-19 Vaccination.

ABSTRACT: A 72-year-old woman was referred for whole-body 111In-pentetreotide scintigraphy with SPECT/CT. There was increased uptake of lymphadenopathy in the left axilla and left deltoid muscle. The patient's history revealed that the patient received the first dose of the COVID-19 vaccine 3 days before the 111In-pentetreotide scintigraphy with SPECT/CT. This case demonstrates that the COVID-19 vaccine can cause 111In-pentetreotide uptake in the lymph nodes and the deltoid muscle.

An adjuvant strategy enabled by modulation of the physical properties of microbial ligands expands antigen immunogenicity.

Activation of the innate immune system via pattern recognition receptors (PRRs) is key to generate lasting adaptive immunity. PRRs detect unique chemical patterns associated with invading microorganisms, but whether and how the physical properties of PRR ligands influence the development of the immune response remains unknown. Through the study of fungal mannans, we show that the physical form of PRR ligands dictates the immune response. Soluble mannans are immunosilent in the periphery but elicit a potent pro-inflammatory response in the draining lymph node (dLN). By modulating the physical form of mannans, we developed a formulation that targets both the periphery and the dLN. When combined with viral glycoprotein antigens, this mannan formulation broadens epitope recognition, elicits potent antigen-specific neutralizing antibodies, and confers protection against viral infections of the lung. Thus, the physical properties of microbial ligands determine the outcome of the immune response and can be harnessed for vaccine development.

SARS-CoV-2 mRNA vaccination elicits a robust and persistent T follicular helper cell response in humans.

SARS-CoV-2 mRNA vaccines induce robust anti-spike (S) antibody and CD4+ T cell responses. It is not yet clear whether vaccine-induced follicular helper CD4+ T (TFH) cell responses contribute to this outstanding immunogenicity. Using fine-needle aspiration of draining axillary lymph nodes from individuals who received the BNT162b2 mRNA vaccine, we evaluated the T cell receptor sequences and phenotype of lymph node TFH. Mining of the responding TFH T cell receptor repertoire revealed a strikingly immunodominant HLA-DPB1∗04-restricted response to S167-180 in individuals with this allele, which is among the most common HLA alleles in humans. Paired blood and lymph node specimens show that while circulating S-specific TFH cells peak one week after the second immunization, S-specific TFH persist at nearly constant frequencies for at least six months. Collectively, our results underscore the key role that robust TFH cell responses play in establishing long-term immunity by this efficacious human vaccine.

Temporal metabolic response to mRNA COVID-19 vaccinations in oncology patients.

BACKGROUND: mRNA COVID-19 vaccines are known to provide an immune response seen on FDG PET studies. However, the time course of this metabolic response is unknown. We here present a temporal metabolic response to mRNA COVID-19 vaccination in oncology patients undergoing standard of care FDG PET. METHODS: 262 oncology patients undergoing standard of care FDG PET were included in the analysis. 231 patients had at least one dose of mRNA COVID-19 vaccine while 31 patients had not been vaccinated. The SUVmax of the lymph nodes ipsilateral to the vaccination was compared to the contralateral to obtain an absolute change in SUVmax (ΔSUVmax). RESULTS: ΔSUVmax was more significant at shorter times between FDG PET imaging and COVID-19 mRNA vaccination, with a median ΔSUVmax of 2.6 (0-7 days), 0.8 (8-14 days), and 0.3 (> 14 days), respectively. CONCLUSION: Consideration should be given to performing FDG PET at least 2 weeks after the COVID-19 vaccine.

GeGen QinLian decoction alleviate influenza virus infectious pneumonia through intestinal flora.

Influenza in humans is often accompanied by gastroenteritis-like symptoms. GeGen QinLian decoction (GQD), a Chinese herb formula, has been widely used to treat infectious diarrhea for centuries and has the effect of restoring intestinal flora. Studies have also reported that GQD were used to treat patients with influenza. However, whether regulating the intestinal flora is one of the ways GQD treats influenza has not been confirmed. In present research, we conducted a systemic pharmacological study, and the results showed that GQD may acts through multiple targets and pathways. In influenza-infected mice, GQD treatment reduced mortality and lung inflammation. Most importantly, the mortality and lung inflammation were also reduced in influenza-infected mice that have undergone fecal microbiota transplantation (FMT) from GQD (FMT-GQD) treated mice. GQD treatment or FMT-GQD treatment restores the intestinal flora, resulting in an increase in Akkermansia_muciniphila, Desulfovibrio_C21_c20 and Lactobacillus_salivarius, and a decrease in Escherichia_coli. FMT-GQD treatment inhibited the NOD/RIP2/NF-κB signaling pathway in the intestine and affected the expression of downstream related inflammatory cytokines in mesenteric lymph nodes (mLNs) and serum. In addition, FMT-GQD treatment showed systemic protection by restraining the inflammatory differentiation of CD4+ T cells. In conclusion, our study shows that GQD can affect systemic immunity, at least in part, through the intestinal flora, thereby protect the mice against influenza virus infectious pneumonia.

Axillary Lymph Nodes Hypermetabolism After BNT162b2 mRNA COVID-19 Vaccination in Cancer Patients Undergoing 18F-FDG PET/CT: A Cohort Study.

PURPOSE: Recognition of the pattern of FDG uptake in hypermetabolic axillary lymph nodes (HALs) and association with recent messenger RNA (mRNA) vaccination are important to prevent patient anxiety and further needless examinations or costly biopsies in cancer patients. MATERIALS AND METHODS: This study was a retrospective cohort study in a single tertiary care institution. We investigate the occurrence and pattern of HAL on FDG PET/CT scans from 650 consecutive cancer patients with recent BNT162b2 mRNA COVID-19 vaccination. RESULTS: Between December 20, 2020, and February 8, 2021, 650 patients (351 female patients [54%]; mean age, 68.9 years) had recent mRNA COVID-19 vaccination and an FDG PET/CT scan. HALs were found in 57 (14.5%) of 394 patients (95% confidence interval [CI], 10.9%-18.7%) 12.3 ± 5.9 (1-22) days after dose 1 and in 111 (43.3%) of 256 patients (95% CI, 35.3%-52.2%; P < 0.0001) after 7.5 ± 5.4 (1-22) days after dose 2. There was no difference between dose 1 and dose 2 concerning SUVmax (3.7 ± 1.8 [1.3-11.3] and 4.5 ± 3.9 [1.4-26.3], P = 0.13, respectively), SUVmean (2.1 ± 1.0 [0.7-6.5] and 2.7 ± 2.4 [0.8-17], P = 0.08, respectively), and reactogenicity volume (2.7 ± 2.3 [0.2-11.6] cm3 and 2.7 ± 2.4 [0.2-15.5] cm3, P = 0.98, respectively). There was no difference in number and in size of positive lymph nodes between dose 1 and dose 2: 3.2 ± 2.2 (1-10) and 3.7 ± 2.4 (1-12) (P = 0.18), and 1.4 ± 0.4 cm (0.7-2.5 cm) and 1.5 ± 0.4 cm (0.6-3.2 cm) (P = 0.75), respectively. CONCLUSIONS: A cluster pattern of hypermetabolic ipsilateral small axillary lymph nodes is common after mRNA COVID-19 vaccination, mainly after the second injection.

COVID-19 Vaccine-Related Local FDG Uptake.

ABSTRACT: We present a case of increased FDG uptake in the lymph nodes after COVID-19 vaccine administration. Restaging PET/CT scan of a 70-year-old woman with a history of multiple relapsed Hodgkin lymphoma showed muscle activity in the left upper arm laterally, which is in the deep musculature of the left deltoid muscle. There was also increased activity in several normal-sized left axillary nodes as well. On further review of the patient's history, she had received her second shot of the Pfizer-BioNTech COVID-19 vaccine approximately 2 days before the restaging PET/CT scan.

COVID-19 Vaccination Manifesting as Incidental Lymph Nodal Uptake on 18F-FDG PET/CT.

ABSTRACT: Benign uptake on 18F-FDG PET can be seen with inflammatory conditions. We report a case of an 86-year-old woman with successfully treated nasal melanoma who underwent routine follow-up 18F-FDG PET, day 6 after the second dose of Pfizer-BioNTech COVID-19 vaccine inoculated in the left deltoid muscle. 18F-FDG PET showed increase tracer uptake in the left deltoid muscle and in 2 normal-sized left subpectoral nodes. These findings were considered secondary to vaccination. With the current drive of global COVID-19 immunization, this case highlights the importance of documenting vaccination history at the time of scanning to avoid false-positive results.

Novel insight from the first lung transplant of a COVID-19 patient.

BACKGROUND: To reveal detailed histopathological changes, virus distributions, immunologic properties and multi-omic features caused by SARS-CoV-2 in the explanted lungs from the world's first successful lung transplantation of a COVID-19 patient. MATERIALS AND METHODS: A total of 36 samples were collected from the lungs. Histopathological features and virus distribution were observed by optical microscope and transmission electron microscope (TEM). Immune cells were detected by flow cytometry and immunohistochemistry. Transcriptome and proteome approaches were used to investigate main biological processes involved in COVID-19-associated pulmonary fibrosis. RESULTS: The histopathological changes of the lung tissues were characterized by extensive pulmonary interstitial fibrosis and haemorrhage. Viral particles were observed in the cytoplasm of macrophages. CD3+ CD4- T cells, neutrophils, NK cells, γ/δ T cells and monocytes, but not B cells, were abundant in the lungs. Higher levels of proinflammatory cytokines iNOS, IL-1ß and IL-6 were in the area of mild fibrosis. Multi-omics analyses revealed a total of 126 out of 20,356 significant different transcription and 114 out of 8,493 protein expression in lung samples with mild and severe fibrosis, most of which were related to fibrosis and inflammation. CONCLUSIONS: Our results provide novel insight that the significant neutrophil/ CD3+ CD4- T cell/ macrophage activation leads to cytokine storm and severe fibrosis in the lungs of COVID-19 patient and may contribute to a better understanding of COVID-19 pathogenesis.