Circulating extracellular particles from severe COVID-19 patients show altered profiling and innate lymphoid cell-modulating ability.

Introduction: Extracellular vesicles (EVs) and particles (EPs) represent reliable biomarkers for disease detection. Their role in the inflammatory microenvironment of severe COVID-19 patients is not well determined. Here, we characterized the immunophenotype, the lipidomic cargo and the functional activity of circulating EPs from severe COVID-19 patients (Co-19-EPs) and healthy controls (HC-EPs) correlating the data with the clinical parameters including the partial pressure of oxygen to fraction of inspired oxygen ratio (PaO2/FiO2) and the sequential organ failure assessment (SOFA) score. Methods: Peripheral blood (PB) was collected from COVID-19 patients (n=10) and HC (n=10). EPs were purified from platelet-poor plasma by size exclusion chromatography (SEC) and ultrafiltration. Plasma cytokines and EPs were characterized by multiplex bead-based assay. Quantitative lipidomic profiling of EPs was performed by liquid chromatography/mass spectrometry combined with quadrupole time-of-flight (LC/MS Q-TOF). Innate lymphoid cells (ILC) were characterized by flow cytometry after co-cultures with HC-EPs or Co-19-EPs. Results: We observed that EPs from severe COVID-19 patients: 1) display an altered surface signature as assessed by multiplex protein analysis; 2) are characterized by distinct lipidomic profiling; 3) show correlations between lipidomic profiling and disease aggressiveness scores; 4) fail to dampen type 2 innate lymphoid cells (ILC2) cytokine secretion. As a consequence, ILC2 from severe COVID-19 patients show a more activated phenotype due to the presence of Co-19-EPs. Discussion: In summary, these data highlight that abnormal circulating EPs promote ILC2-driven inflammatory signals in severe COVID-19 patients and support further exploration to unravel the role of EPs (and EVs) in COVID-19 pathogenesis.

Hairy Cell Leukemia in a Filipino Male during the COVID-19 Pandemic - Report of a Rare Case

Hairy cell leukemia (HCL) is a rare, chronic, mature B-cell lymphoproliferative disorder accounting for 2% of all leukemias. In this paper, we would like to present our experience in the management of HCL in a financially limited setting where other diagnostic tests and chemotherapy are unavailable. The case report aims to emphasize the recognition of the distinctive morphology of hairy cells in the peripheral blood in the consideration of the initial diagnosis. A 60-year-old Filipino male was incidentally found to have anemia, thrombocytopenia and an absolute neutrophilic count below 1,000 in a pre-operative clearance for elective herniorrhaphy. Blood smear revealed atypical lymphocytes with hair like cytoplasmic projections. CT-scan of the abdomen showed splenomegaly and prominent paraaortic nodes. Flow cytometry of the bone marrow aspirate was consistent with an involvement of a Mature B cell neoplasm markers CD19, CD20, CD22 and surface immunoglobulin lambda and hairy cell leukemia markers CD11c, CD103 and CD25. He responded to six-weekly sessions of Cladribine with remission of the bone marrow and hematologic parameters. HCL is a rare type of a mature B cell neoplasm characterized by pancytopenia, splenomegaly, bone marrow fibrosis and the presence of atypical lymphoid cells with hairy projections in blood, bone marrow and spleen. Immunophenotyping express CD11c, CD103, CD123, and CD25. BRAF V600E mutation is the disease defining genetic event. Cladribine and Pentostatin are the first line of treatment. Cases of leukemia can be easily overlooked because of the mild derangement in the complete blood count. A meticulous differential review of the atypical lymphocyte, is the first step in the diagnosis of this rare disease.Copyright © 2022, Philippine College of Physicians. All rights reserved.

Kikuchi-Fujimoto disease following COVID-19 infection in a 13-year- old girl

Background/Purpose: Kikuchi-Fujimoto disease (KFD) is a rare, self-limited histiocytic necrotizing lymphadenitis. Although it is of uncertain aetiology, it is associated with viral infections and autoimmune diseases. Hence, it is crucial to identify KFD from other conditions with lymphadenopathy. Here we present a case of KFD after COVID-19 infection. Method(s): Medical records were traced and reviewed Results: A previously healthy 13-year- old girl was admitted in April 2022 with four weeks of fever, dry cough, loss of weight, followed by 1 week history of painful cervical lymphadenopathy and nonspecific maculopapular rash. She received her second dose of Covid 19 vaccine in January 2022. Unfortunately, she was diagnosed with CAT II, COVID 19 infection in March 2022. There was no history of allergy, recent traveling and cat scratch injury. Clinically there was no strawberry tongue, erythema of the lips, conjunctivitis or distal extremities changes to suggest Kawasaki disease. She was initially diagnosed with infection related lymphadenitis, treated with oral azithromycin for three days and intravenous ceftriazone for one week with no improvement. Her laboratory results showed hypochromic microcystic anaemia with leucopenia, raised inflammatory markers and lactate-dehydrogenese levels. Extensive workup for infection was unremarkable. Immunology test showed ANA, ANCA, ENA were negative with normal complements. Ultrasound abdomen was normal. Excisional lymph node biopsy revealed confluent areas of necrosis surrounded by histiocytes (CD68+) with absent of neutrophils. No granuloma or atypical lymphoid cells seen. Based on histopathology report, diagnosis of KFD was established. As she was not able tolerate orally, IV hydrocortisone was started and subsequently switched to oral prednisolone. She responded well to corticosteroids with fever subsided within a day and cervical lymphadenopathy reducing in size and resolved in one month. Prednisolone was able to taper off by two months. She showed complete recovery with no recurrence during follow-up. Conclusion(s): In persistent febrile painful lymphadenopathy, excision lymph node biopsy is essential to establish definite diagnosis. This case highlights the possible association between COVID-19 and KFD.

Asymptomatic SARS-CoV-2 Infection in Children's Tonsils

Introduction: The SARS-CoV-2 pandemic killed over 6 million people worldwide. Children were described to have predominantly mild or asymptomatic infections and to be less exposed to the virus, at least for the initial variants. In the present study, we describe how SARS-CoV-2 can silently infect tonsils and adenoids in children undergoing adenotonsillectomy. Method(s): In this cross-sectional study we assessed children who underwent adenotonsillectomy between October 2020 and September 2021 in a secondary hospital in Brazil. All the caregivers denied any symptom of acute viral upper airway infection in the month prior to surgery. Briefly, nasal cytobrush (NC), nasal wash (NW) and tonsillar tissue fragments posttonsillectomy were tested by RT-PCR, immunohistochemistry (IHC), in situ immunofluorescence (IF), and flow cytometry. Result(s): A total of 48 children (18 females, median age 5.5 years) were enrolled. None of them had been vaccinated against COVID-19 at the time of surgery. Only 2 had a history of previous COVID-19 diagnosis, 3 and 5 months, respectively, before surgery. SARS-CoV-2 RNA was detected in 25% (12) of patients-20% in palatine tonsils, 16.27% in the adenoids, 10.41% in NC, and 6.25% in NW. IHC labeling showed viral nucleoprotein presence in both adenoids and palatine tonsils, in epithelial surface and lymphoid cells from extrafollicular and follicular regions. In 5 out of 7 patients, in situ IF showed the expression of ACE2 and TMPRSS2 and viral spike protein in the tonsillar tissue. Flow cytometry revealed that SARS-CoV-2 is predominantly observed in CD123+ dendritic cells (10.57% of all tested sites), followed by CD14+ monocytes (6.32%). Conclusion(s): According to these results, the prevalence of SARS-CoV-2 infection seems to be higher than expected and underdiagnosed in children at this age group. Palatine tonsils and adenoids are important sites of infection and may be a reservoir for the virus. Nevertheless, it is still unclear the impact of these results on virus transmission.

HEMORRHAGIC PLEURAL EFFUSION IN A PATIENT WITH CHRONIC LYMPHOCYTIC LEUKEMIA ON IBRUTINIB THERAPY

SESSION TITLE: Problems in the Pleura Case Posters 1 SESSION TYPE: Case Report Posters PRESENTED ON: 10/17/2022 12:15 pm - 01:15 pm INTRODUCTION: Ibrutinib is an irreversible inhibitor of Bruton's tyrosine kinase (Btk), approved for treatment of a variety of B-cell malignancies, including chronic lymphocytic leukemia (CLL). There is an association of increased risk of bleeding with ibrutinib due to platelet dysfunction caused by the medication. Bleeding is usually non-life threating such as subcutaneous or mucosal bleeding, epistaxis, and ecchymosis. But major bleeding has been reported such as intracranial hemorrhage and gastrointestinal hemorrhage. Thoracic complications from ibrutinib are rare. Below is a case report discussing a hemorrhagic pleural effusion thought to be caused by Ibrutinib. CASE PRESENTATION: Patient is a 78-year-old male initially diagnosed with CLL on flow cytometry showing a low-grade B cell lymphoproliferative process. Patient was monitored by Hematology and when kappa light chain numbers began to rise, a bone marrow biopsy was performed showing 90% infiltration of the marrow with lymphoid cells. Patient was started on Ibrutinib therapy and responded well to treatment. A year after starting therapy, patient presented to the emergency room with increased shortness of breath and fatigue. Patient was found to be COVID-19 positive and chest x-ray showed a large right sided pleural effusion. Thoracentesis was performed draining 1650cc of bloody fluid. Fluid studies revealed a lymphocytic effusion with RBC count 1,185375, WBC of 1751. Cultures and cytology were negative. On further history, patient was without recent trauma or surgery, CTA chest was negative for pulmonary embolism. QuantiFERON Gold test was negative, indicating low likelihood of tuberculosis. Patient was not on any antiplatelet or systemic anticoagulation medications. Ibrutinib therapy was held during hospitalization and pleural effusion did not reaccumulate. Patient passed away during hospital stay secondary to respiratory failure due to COVID-19. DISCUSSION: Ibrutinib is an orally bioavailable bruton tyrosine kinase inhibitor (BTKi) and forms an irreversible covalent bound to BTK at the Cysteine-481 residue. Ibrutinib predisposes to bleeding by inhibiting BTK and Tec, which play a role in the inhibitory signaling pathway of platelet collagen receptors such as glycoprotein VI (GP VI) and C-type lectin-like receptor 2 (CLEC-2). Our patient had no other risk factors for developing a hemorrhagic effusion. CLL itself can cause malignant effusions, one study found the incidence of malignant effusions among patients with CLL to be 9%, but the effusion was noted to be serous or serosanguinous and there was pleural involvement in all patients which was not the case in our patient. CONCLUSIONS: There is currently a minimal amount of data to guide clinicians regarding the use of ibrutinib in patients at high risk of bleeding or on anticoagulant or antiplatelet therapy. It is important to realize bleeding complications related to ibrutinib therapy can occur. Reference #1: Shatzel JJ, Olson SR, Tao DL, McCarty OJT, Danilov AV, DeLoughery TG. Ibrutinib-associated bleeding: pathogenesis, management and risk reduction strategies. J Thromb Haemost. 2017;15(5):835-847. doi:10.1111/jth.13651 Reference #2: Burger JA, Tedeschi A, Barr PM, et al. Ibrutinib as Initial Therapy for Patients with Chronic Lymphocytic Leukemia. N Engl J Med. 2015;373(25):2425-2437. doi:10.1056/NEJMoa1509388 Reference #3: Paydas S. Management of adverse effects/toxicity of ibrutinib. Crit Rev Oncol Hematol. 2019;136:56-63. doi:10.1016/j.critrevonc.2019.02.001 DISCLOSURES: No relevant relationships by fatima ali No relevant relationships by Joan Wiley

DOES COVID-19 INCREASE YOUR RISK OF DEVELOPING HAIRY CELL LEUKEMIA?

SESSION TITLE: Pathology Identifying Chest Infections Case Report Posters SESSION TYPE: Case Report Posters PRESENTED ON: 10/17/2022 12:15 pm - 01:15 pm INTRODUCTION: Coronavirus disease 2019 (COVID-19) patients presented in a wide variety and had multiple complications. The well-known associations found are myocardial infraction, pulmonary embolism, meningitis, encephalitis. We are presenting a new diagnosis of Hairy cell leukemia in COVID 19 patients. CASE PRESENTATION: We present a 55-year-old pleasant female with no significant past medical history;non immunocompromised who presented with 7 days history of shortness of breath on exertion, fever, fatigue, and cough. Her physical exam was unremarkable, but she was desaturating on presentation hence was placed on oxygen via nasal canula. On work up she tested positive for COVID-19. Initial chest Xray revealed bilateral diffuse pulmonary infiltrates. Complete blood count (CBC) showed pancytopenia with white blood cell count (WBC) 0.8 × 103/μL (4–10 × 103/μL), absolute neutrophil count (ANC) 0.5 × 103/μL (2–7 × 103/μL), hemoglobin (Hgb) 10.4 g/dL (13.0–17.0 g/dL), and platelet count 156× 103/μL (150–400 × 103/μL). She received treatment for COVID 19 pneumonia as per the protocol. On repeat CBC check there was minimal improvement in her counts. The rest of her WBC differential showed a lymphopenia with ALC ranging from 350–500 with no other obvious immature cells or blasts to suggest a myeloid neoplasm such as acute leukemia. Work-up including vitamin B12, folate, TSH, EBV, ANA, and hepatitis were unremarkable. She also received treatment with supportive granulocyte colony-stimulating factor (G-CSF) but there was minimal improvement. As her pancytopenia persisted for 1 week the peripheral blood smear was done which showed pancytopenia (with prominent red cell agglutination, with rare, atypical lymphoid cells with multiple hairy projections. A bone marrow (BM) aspirate was hypocellular showing markedly decreased trilineage hematopoiesis with atypical lymphoid cells with oval or indented nuclear borders, unclumped chromatin, absent or inconspicuous nucleoli, and moderate to abundant pale blue cytoplasm with multiple circumferential cytoplasmic projections (hairy cells) [Figure:1]. The hairy cells showed strong positivity for CD20[Figure:2]. She was followed up by hematology and was started on treatment. DISCUSSION: Hairy cell leukemia (HCL) is a rare B cell lymphoproliferative disease with marked cytopenia and circulating leukemia cells. Multiple viruses (EBV, HTLV1) were found to be associated with multiple different malignancies. It is found that COVID19 is not associated with any malignancy so far, but our patient got diagnosed with HCL during COVID19 illness. CONCLUSIONS: The association of HCL could be an incidental finding but we need to do further studies to clarify the associations Reference #1: Kohla, Samah et al. "A Rare Case of Hairy Cell Leukemia with Unusual Loss of CD123 Associated with COVID-19 at the Time of Presentation.” Case reports in oncology vol. 13,3 1430-1440. 4 Dec. 2020, doi:10.1159/000512830 DISCLOSURES: No relevant relationships by Apurwa Karki No relevant relationships by Shobha Mandal No relevant relationships by Rajamurugan Meenakshisundaram

INDIVIDUALS LIVING WITH CANCER IN TURKEY AND THE COVID-19 PANDEMIC

The aim of this study is to determine the problems faced by individuals living with cancer (ILCs) in accessing health services during the COVID-19 pandemic in Turkey. This qualitative study’s sample consisted of 18 volunteer interviewees from 10 cancer-related patient associations in Turkey. Research data were collected by semi-structured interview method. Data collection and analysis were carried out simultaneously. In the sessions where all researchers participated together, the data were coded with a common view, and main and sub-themes were determined. In the analysis of the data the inductive thematic analysis method was applied. Information was gathered under two main themes: compliance with the measures taken and access to health services. Lack of information about nutrition, physical activity, psychological problems, caused by the lockdown and social distance measures taken within the scope of the pandemic should be accepted as problems within the scope of the right of individuals to access health, and additional programs should be prepared to minimize these. Cancer types should be considered in delaying diagnosis, treatment, and controls related to cancer, so that patients are not harmed at least or at all. It is important to ensure that patients do not hesitate to attend diagnosis, treatment, and controls with the anxiety of being infected with COVID-19, both in transportation to health facilities and in terms of preventing transmission in health facilities.

Myeloid and lymphoid cell abnormalities persist in the intestinal mucosa of patients who recover from COVID-19 infection

Background: Although respiratory failure is the hallmark of severe disease, it is increasingly clear that Coronavirus Disease 2019 (COVID-19) is a multi-system disorder. The presence of gastrointestinal (Gl) involvement by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been suggested by epidemiological, clinical, non-human primate, invitro (enteroid) and ex-vivo (human biopsy) studies. Having recently documented persistence of SAR-CoV-2 within the intestinal epithelium 7 months after infection, here we aimed to study mucosal immune cell abnormalities in individuals with prior history of COVID-19. Methods: Individuals with previous COVID-19 diagnosis (by either RT- PCR or seroconversion) and controls (without RT-PCR or serological evidence of prior COVID-19 infection) undergoing endoscopic evaluation were recruited into the study (Table 1,2). Colonic and small intestinal (duodenal and ileal) biopsies were analyzed by multiparameter flow cytometry for mucosal immune cell populations including myeloid cells (classical and non-classical monocytes, dendritic cell subsets), T cells (subsets and activation state), B cells (including plasma cells). Persistence of viral antigens was determined by immunofluorescence microscopy (n=30) using a previously published anti-nucleocapsid (NP) antibody. Results: Thirty subjects with a previous history of COVID-19 (post- COVID), median of 4 months from diagnosis (range 1-10 months), were recruited and compared with 40 normal volunteer (NV) controls. Relative to controls, post-COVID subjects displayed higher frequencies of classical (CD14+) monocytes in both, the colon and the small bowel, while significantly higher frequencies of conventional dendritic cells (cDC) 1 (lin-HLA-DRhiCD14-CD11c+CD141+) and cDC2 (lin-HLA-DRhiCD14-- CD11c+CD1c+) were noted in the colon only. Among T cell subsets, CD8+ tissue resident memory T cells (CD8+CD69+CD103+) were significantly increased in colon of post-COVID subjects compared to NV. Among B cell subsets, plasma cells (CD3-CD27+CD38hi) trended higher (p=0.06), while mucosal B cells (CD3-CD19+) were significantly lower in the terminal ileum of post-COVID subjects compared to NV. Finally, with IF, we detected SARS-CoV-2 NP in 10 out of 30 (33%) of post-COVID subjects (Figure 1). There were no significant correlations of these cell populations with either time after the infection or IF positivity. Conclusion: Innate and adaptive immune cell abnormalities persist in the intestinal mucosa of post-COVID subjects for up to 10 months and may reflect viral persistence or immune cell dysregulation in the intestines. These findings have major implications for understanding the pathogenesis of long term sequela of COVID-19, including long-haul COVID.

Regulation and Function of ILC3s in Pulmonary Infections.

Lower respiratory infections are among the leading causes of morbidity and mortality worldwide. These potentially deadly infections are further exacerbated due to the growing incidence of antimicrobial resistance. To combat these infections there is a need to better understand immune mechanisms that promote microbial clearance. This need in the context of lung infections has been further heightened with the emergence of SARS-CoV-2. Group 3 innate lymphoid cells (ILC3s) are a recently discovered tissue resident innate immune cell found at mucosal sites that respond rapidly in the event of an infection. ILC3s have clear roles in regulating mucosal immunity and tissue homeostasis in the intestine, though the immunological functions in lungs remain unclear. It has been demonstrated in both viral and bacterial pneumonia that stimulated ILC3s secrete the cytokines IL-17 and IL-22 to promote both microbial clearance as well as tissue repair. In this review, we will evaluate regulation of ILC3s during inflammation and discuss recent studies that examine ILC3 function in the context of both bacterial and viral pulmonary infections.