61 Biomarkers of favorable prognosis guides the identification of tumor reactive CD4+ and CD8+ TILs in endometrial cancer

BackgroundEndometrial cancer (EC) is the most prevalent gynecological cancer and it can be categorized into four molecular subtypes; ultramutated POLE, hypermutated MSI, CNL and CNH. To date, the prevalence, specificity and phenotype of tumor infiltrating lymphocytes (TILs), and their exact role in EC remain controversial. Thus, a thorough investigation deciphering the phenotypic landscape of EC-infiltrating T lymphocytes and their anti-tumor reactivity is still missing.MethodsIn order to study the implications of the T-cells infiltrating EC for prognosis or susceptibility to immune checkpoint inhibitors, we analyzed the phenotypic traits of CD8 and CD4 EC-resident T cells from single-cell suspensions (n=47) by multicolor flow cytometry (19 biomarkers). Correlation analyses between the phenotype of the TILs, EC molecular subgroups and the survival of the patients were performed to identify biomarkers that could predict prognosis or survival. This identification guided the isolation of specific CD8 and CD4 subpopulations based on the differential expression of the selected biomarkers to evaluate their ability to recognize tumor (figure 1).ResultsOur analysis evidenced the presence of CD8+ and CD4+ T cells with distinct levels of PD-1 expression: cells that did not express PD-1 (PD-1-), cells expressing intermediate (PD-1dim) or high (PD-1hi) levels of PD-1. We found that TIM-3+, CD39+, CXCL13+, BCL6+ or Ki67+ cells frequently co-expressed almost exclusively on the PD-1hi, but not on the PD-1- or dim CD8+ TILs. On the other hand, CD4+ TILs displayed co-expression of TIM-3, CD103, CD39, CD38, HLA-DR, CXCL13, BCL6, CXCR5 or Ki67 within the PD-1hi, but also PD-1dim cells. Importantly, our data shows that the frequency of PD-1hi or CD39+ CD8+ EC TILs, and of PD-1hi but not CD39+ CD4+ TILs was associated with improved survival. Of the 5 predominant CD8+ tumor-resident subpopulations observed (PD-1-CD39-, PD-1dimCD39-, PD-1dimCD39+, PD-1hiCD39- and PD-1hiCD39+) the PD-1hiCD39+, but not the PD-1hiCD39- lymphocytes, harbored the highest frequency of autologous tumor-reactive lymphocytes in all four EC tumors studied. However, both the CD4+ PD-1hiCD39+ and the PD-1hiCD39- contained autologous tumor-reactive lymphocytes in all four tumors screened; being the PD-1hiCD39+ cells the subpopulation containing the majority of tumor-reactive CD4+ cells.Abstract 61 Figure 1Schematic workflow of the study. A section of a primary EC tumor resection is digested and stained with specific antibodies to characterize the phenotype of CD8 and CD4 TILs by flow cytometry (upper panel). Targeted sequencing and IHC including typically altered genes in EC are performed in order to molecularly classify the patient‘s cohort into different disease subgroups. Combining the data generated by flow cytometry, targeted sequencing and IHC, specific biomarkers on CD8 and CD4 TILs are investigated for their potential role in predicting molecular subtypes or survival (middle panel). CD8 and CD4 TILs are isolated from the tumor digest based on the differential expression of PD-1 and CD39 and the specific isolated CD8 and CD4 subpopulations are cultured in vitro to expand them to large numbers. The expanded CD8 and CD4 subpopulations are subsequently screened for tumor recognition by co-culturing the isolated subpopulations with autologous tumor cell lines. Tumor recognition is assessed by measuring the up-regulation of the activation markers 4-1BB or OX40 on CD8+ or CD4+ T cells, respectively, by flow cytometry, and by measuring IFN-γ production by ELISPOT.ConclusionsOverall, our data suggest that CD39 expression on CD8+PD-1hi EC-resident T cells defines a tumor-reactive population that plays an important role in protecting patients from recurrence after surgery. However, PD-1 expression but not CD39 on CD4+ TILs, better guides the identification of lymphocyte subsets with enriched tumor-recognition potential that contribute to improved clinical benefit in EC.Ethics ApprovalThis study was approved by the ‘Comité de Ética de Investigación con Medicamentos del Hospital Universitario Vall d’Hebron’ institution’s Ethics Board; approval number PR(AG)537/2019.

Somatic Mutations and Autoimmunity

Autoimmune diseases are among the most common chronic illness caused by a dysregulated immune response against self-antigens. Close to 5% of the general population in Western countries develops some form of autoimmunity, yet its underlying causes, although intensively studied, are still not fully known, and no curative therapies exist. It is well established that autoimmune diseases have common mechanisms and are caused by both genetic and non-genetic risk factors. One novel risk factor that can contribute to autoimmunity is somatic mutations, in a role parallel to their role in cancer. Somatic mutations are stochastic, de novo, non-inherited mutations. In this hypothesis, the persistent proliferation of self-reactive lymphocytes (that is usually hindered by a series of checkpoints) is permitted, due to somatic mutations in these expanding cells, allowing them to bypass multiple regulatory checkpoints, causing autoimmunity. This novel concept of the contribution of these mutations in non-malignant diseases has recently started to be explored. It proposes a novel paradigm for autoimmunity etiology and could be the missing piece of the autoimmunity puzzle.

COVID-19 (SARS-CoV-2) lymphocyte responses are associated with inflammatory biomarkers in total joint replacement surgery candidates pre-operatively

Background Recent studies indicate that, in addition to antibody production, lymphocyte responses to SARS-CoV-2 may play an important role in protective immunity to COVID-19 and a percentage of the general population may exhibit lymphocyte memory due to unknown/asymptomatic exposure to SARS-CoV-2 or cross-reactivity to other more common coronaviruses pre-vaccination. Total joint replacement (TJR) candidates returning to elective surgeries (median age 68 years) may exhibit similar lymphocyte and/or antibody protection to COVID-19 prior to vaccination Methods In this retrospective study, we analyzed antibody titters, lymphocyte memory, and inflammatory biomarkers specific for the Spike and Nucleocapsid proteins of the SARS-CoV-2 virus in a cohort of n=73 returning TJR candidates (knees and/or hips) pre-operatively. Results Peripheral blood serum of TJR candidate patients exhibited a positivity rate of 18.4% and 4% for IgG antibodies specific for SARS-CoV-2 nucleocapsid and spike proteins, respectively. 13.5% of TJR candidates exhibited positive lymphocyte reactivity (SI > 2) to the SARS-CoV-2 nucleocapsid protein and 38% to the spike protein. SARS-CoV-2 reactive lymphocytes exhibited a higher production of inflammatory biomarkers (i.e., IL-1β, IL-6, TNFα, and IL-1RA) compared to non-reactive lymphocytes. Conclusions A percentage of TJR candidates returning for elective surgeries exhibit pre-vaccination positive SARS-CoV-2 antibodies and T cell memory responses with associated pro-inflammatory biomarkers. This is an important parameter for understanding immunity, risk profiles, and may aid pre-operative planning. Trial registration Retrospectively registered.

Treatment of severe thrombocytopenia with platelet biotherapic and Phosphorus

Background Thrombocytopenia is a decrease in the number of platelets in the blood resulting from disorders of production, distribution or destruction, leading to bleeding. The respective treatment of thrombocytopenia is usually based on corticotherapy and platelet transfusion. Aims Report the evolution of homeopathic treatment in a 12 years old Maltese canine cardiopathic patient with thrombocytopenia associated with the diagnosis of Ehrlichia canis. Methods Replacement of corticoid and transfusion by Platelet Biotherapic, to stimulate platelet production and high diluted Phosphorus to contain the bleeding. Results On 01/28/19, the patient presented thrombocytopenia of 5.000/mm³ with large platelets, petechials and suffusion hemorrhages in dorsal and ventral regions, extensive acute cervical hematoma due to blood collection; anisocytosis, polychromasia and Howell Jolly corpuscle in red series; and also reactive lymphocytes, monocytes active and toxic neutrophils in white series. On 01/30/19, initiated the administration of 3 globules of Platelet Biotherapic 12CH every 12 hours; 3 globules of Phosphorus 6CH every 24 hours, both oral; and topical phytotherapeutic use of Arnica montana once daily. Three days later, it was observed the complete absence of petechials and suffusion hemorrhages, with elevation of platelets count to 74.000/mm³ and mild leukocytosis with improvement in overall patient well-being. On 02/06/19, there was regression of hematoma and leukocytosis, in addition to the platelet count in 95.000/mm³. On 02/14/19, due to slight decrease in platelets to 92.000/mm³, the frequency of Phosphorus 6CH was changed every 12 hours. On 02/20/19, the new platelet count reached 126.000/mm³ with standardized morphology and no Howell Jolly record. Conclusion The homeopathies (High dilution medicine) have proven to be successful in the treatment of thrombocytopenia without causing side effects.

Scatterplot Variations Seen in Malaria Using Automated Hematological Analyzers: A Series of Ten Cases

Background: Malaria is a major health problem in India. Complete blood count and peripheral blood smear (PBS) is important for its diagnosis. Inter observer variation makes PBS fallible. Rapid diagnostic tests cannot detect low parasitemia and mixed infections. Scatterplot from automated analyzers have shown variations previously which might be exploited. Methods: Scatterplot patterns of ten samples of confirmed malaria and 100 control samples were derived and other infections ruled out by culture and serology as a part of descriptive study between July and August 2018. Each malarial scatterplot was compared with the control pattern for abnormalities and their frequency noted. Results: All the ten samples belonged to Plasmodium vivax species. Abnormalities detected included split in neutrophilic region, eosinophil-neutrophil merge, neutrophil graying, lymphopenia, ghost red blood cells (RBC), eosinophil split, reactive lymphocytes, monocytosis, pseudoeosinophilia, neutrophilic leukocytosis Conclusion: Variations in scatterplot patterns are seen in malaria and provide clues to the diagnosis of malaria.

Use of immune repertoire sequencing to resolve discordant microscopic and immunochemical findings in a case of T cell-rich large B cell lymphoma in a young dog

Background Lymphocytic neoplasms with frequent reactive lymphocytes are uncommonly reported in dogs, and can pose a diagnostic challenge. Different diagnostic modalities such as cytology, flow cytometry, histopathology, immunohistochemistry, and clonality testing, are sometimes required for a diagnosis. This report illustrates the value of using a multi-modal diagnostic approach to decipher a complex lymphocytic tumor, and introduces immune repertoire sequencing as a diagnostic adjunct. Case presentation A 10-month-old Great Dane was referred for marked ascites. Cytologic analysis of abdominal fluid and hepatic aspirates revealed a mixed lymphocyte population including numerous large lymphocytes, yielding a diagnosis of lymphoma. Flow cytometrically, abdominal fluid lymphocytes were highly positive for CD4, CD5, CD18, CD45, and MHC II, consistent with T cell lymphoma. Due to a rapidly deteriorating clinical condition, the dog was euthanized. Post mortem histologic evaluation showed effacement of the liver by aggregates of B cells surrounded by T cells, suggestive of hepatic T cell-rich large B cell lymphoma. Immune repertoire sequencing confirmed the presence of clonal B cells in the liver but not the abdominal fluid, whereas reactive T cells with shared, polyclonal immune repertoires were found in both locations. Conclusions T cell-rich large B cell lymphoma is a rare neoplasm in dogs that may be challenging to diagnose and classify due to mixed lymphocyte populations. In this case, the results of histopathology, immunohistochemistry and immune repertoire sequencing were most consistent with a hepatic B cell neoplasm and reactive T cells exfoliating into the abdominal fluid. Immune repertoire sequencing was helpful in delineating neoplastic from reactive lymphocytes and characterizing repertoire overlap in both compartments. The potential pitfalls of equating atypical cytomorphology and monotypic marker expression in neoplasia are highlighted.

The Therapeutic Potential of Regulatory T Cells: Challenges and Opportunities

Regulatory T cells (Tregs) are an immunosuppressive subgroup of CD4+ T cells which are identified by the expression of forkhead box protein P3 (Foxp3). The modulation capacity of these immune cells holds an important role in both transplantation and the development of autoimmune diseases. These cells are the main mediators of self-tolerance and are essential for avoiding excessive immune reactions. Tregs play a key role in the induction of peripheral tolerance that can prevent autoimmunity, by protecting self-reactive lymphocytes from the immune reaction. In contrast to autoimmune responses, tumor cells exploit Tregs in order to prevent immune cell recognition and anti-tumor immune response during the carcinogenesis process. Recently, numerous studies have focused on unraveling the biological functions and principles of Tregs and their primary suppressive mechanisms. Due to the promising and outstanding results, Tregs have been widely investigated as an alternative tool in preventing graft rejection and treating autoimmune diseases. On the other hand, targeting Tregs for the purpose of improving cancer immunotherapy is being intensively evaluated as a desirable and effective method. The purpose of this review is to point out the characteristic function and therapeutic potential of Tregs in regulatory immune mechanisms in transplantation tolerance, autoimmune diseases, cancer therapy, and also to discuss that how the manipulation of these mechanisms may increase the therapeutic options.

Usefulness of the New Hematological Parameter: Reactive Lymphocytes RE-LYMP with Flow Cytometry Markers of Inflammation in COVID-19

Identification of patients with activation of the immune system which indicates the presence of infection is essential, especially in the times of the global coronavirus 2019 (COVID-19) pandemic. The aim of the present study was to evaluate the reactive lymphocytes (RE-LYMP) parameter in COVID-19 and to correlate it with activation lymphocytes markers by flow cytometry. The study group consisted of 40 patients: with COVID-19 infection (n = 20) and with others virus infections without COVID-19 (COVID-19(−) virus (n = 20)) and 20 healthy donors (HC). Blood count and flow cytometry were performed. The COVID-19(+) group had significantly lower RE-LYMP parameter than the COVID-19(−) virus group (5.45 vs. 11.05, p < 0.05). We observed higher proportion of plasmablasts in the COVID-19(+) and COVID-19(−) virus groups than HC (8.8 vs. 11.1 vs. 2.7, p < 0.05). In the COVID-19(+) there was a lower proportion of CD4+ CD38+ cells than in the other groups (significant differences between COVID-19(+) and COVID-19(−) virus groups). RE-LYMP correlated with activated T lymphocytes CD38+ and HLA-DR+ in the COVID-19(−) virus group, however in the COVID-19(+) group correlations with T lymphocytes CD25+ and CD45RO+ were observed. In summary the analysis of the RE-LYMP together with flow cytometric activation markers can be helpful in identifying and distinguishing patients with COVID-19(+) from other viruses and HC.

Atypical lymphoid cells circulating in blood in COVID-19 infection: morphology, immunophenotype and prognosis value

AimsAtypical lymphocytes circulating in blood have been reported in COVID-19 patients. This study aims to (1) analyse if patients with reactive lymphocytes (COVID-19 RL) show clinical or biological characteristics related to outcome; (2) develop an automatic system to recognise them in an objective way and (3) study their immunophenotype.MethodsClinical and laboratory findings in 36 COVID-19 patients were compared between those showing COVID-19 RL in blood (18) and those without (18). Blood samples were analysed in Advia2120i and stained with May Grünwald-Giemsa. Digital images were acquired in CellaVisionDM96. Convolutional neural networks (CNNs) were used to accurately recognise COVID-19 RL. Immunophenotypic study was performed throughflow cytometry.ResultsNeutrophils, D-dimer, procalcitonin, glomerular filtration rate and total protein values were higher in patients without COVID-19 RL (p<0.05) and four of these patients died. Haemoglobin and lymphocyte counts were higher (p<0.02) and no patients died in the group showing COVID-19 RL. COVID-19 RL showed a distinct deep blue cytoplasm with nucleus mostly in eccentric position. Through two sequential CNNs, they were automatically distinguished from normal lymphocytes and classical RL with sensitivity, specificity and overall accuracy values of 90.5%, 99.4% and 98.7%, respectively. Immunophenotypic analysis revealed COVID-19 RL are mostly activated effector memory CD4 and CD8 T cells.ConclusionWe found that COVID-19 RL are related to a better evolution and prognosis. They can be detected by morphology in the smear review, being the computerised approach proposed useful to enhance a more objective recognition. Their presence suggests an abundant production of virus-specific T cells, thus explaining the better outcome of patients showing these cells circulating in blood.

A Descriptive Study of Blood Films of Patients Serologically Positive for Dengue in Hospital Tengku Ampuan Afzan, Kuantan

Introduction: Dengue is one of the commonest infections in Malaysia and it is a notifiable disease. Even though the diagnosis of classical dengue fever and dengue haemorrhagic fever can be recognized clinically, the diagnosis remains a challenge in areas where it could not be differentiated with other febrile illnesses. The aim of this study was to focus on the specific and consistent morphological features observed in blood films of dengue infection. Materials and Methods: In all 400 cases of dengue infection serologically diagnosed in the Tengku Ampuan Afzan Hospital (HTAA) during May to October 2007, only a total of 27 cases had blood films examined, and thus were included in this study. These blood films were re-examined by two pathologists from HTAA. The full blood count parameters were also retrieved and studied. Results: We consistently found typical reactive lymphocytes [n= 23 (85%)] and thrombocytopenia [n=21, (77.8%)] in the cases. However, leucopenia was present only in 9 cases (33%). Conclusion: The presence of typical reactive lymphocyte is a consistent finding in dengue fever and thus could have a significant role in supporting the diagnosis of dengue infection.