BRAF inhibitor treatment of classical hairy cell leukemia allows successful vaccination against SARS-CoV-2.

In classical hairy cell leukemia (HCL), standard treatments including purine analogs achieve a durable response (up to 90%), but lead to severe immunosuppression and long-lasting depletion of CD4 + T lymphocytes. The BRAF inhibitor vemurafenib is effective in HCL, but its use in first-line treatment is restricted to select clinical situations (e.g. active infection). Its impact on immune function or response to vaccines in HCL is unclear. We treated four HCL patients with vemurafenib during the COVID-19 pandemic and monitored immune reconstitution and response to SARS-CoV-2 immunization. All patients responded to HCL treatment with normalization of peripheral blood counts. No severe infections occurred. As an indication of limited immunosuppression by vemurafenib, stable CD4 + and CD8 + T lymphocyte counts and immunoglobulin levels were observed. Three out of four patients received SARS-CoV-2 vaccination (Pfizer-BioNTech) during treatment with vemurafenib. IgG antibody levels against the spike-protein of SARS-CoV-2 were detected (40-818 AE/ml). Our data suggest that vemurafenib has limited effects on cellular and humoral immune function in HCL, which allows for successful SARS-CoV-2 vaccination. These data support the use of BRAF inhibitors during the current pandemic where continued immune response is necessary for minimizing the COVID-19-related risk of non-vaccinated patients.

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.

Quercetin potentially suppresses renal fibrosis in patients with COVID-19 under hypoxic state

Introduction: Renal fibrosis is a main outcome of acute kidney injury in COVID-19 survivors, which is emerging as a global public health concern. Lung damage in the COVID-19 patients leads to acute and chronic hypoxia, which results in inflammation, epithelial-mesenchymal transformation, and fibrosis in kidney. Quercetin is an abundant flavonoid in plant materials. Previous studies indicate that quercetin alleviates the decline of renal function, suppress epithelial to mesenchymal transformation in renal tubules, and reduce fibrosis. The study aimed to explore potential targets of quercetin on treating renal fibrosis in patients with COVID-19-induced hoxpia. Method(s): Gene/protein targets related to COVID-19, renal fibrosis, or quercetin were searched from ten databases, and Cytoscape 3.8.2 was then used to construct the protein-protein interaction network and to identify the core targets. The Metascape platform was used for bioconcentration analysis, while AutoDock Vina was used as the primary molecular docking tool. In vitro, the combination model of hypoxia- and transforming growth factor-beta (TGF-beta)- treated human proximal tubule epithelial cells (HK2 cells) was applied to determine the reno-protective effect of quercetin. Result(s): The network analysis showed that quercetin targeted on TGF-beta pathway in treating COVID-19 induced renal fibrosis. In the intersection PPI network, 115 targets were obtained, and gene enrichment analysis was conducted on 109 key nodes. Molecular docking analysis revealed that quercetin could spontaneously bind to eight targets on the TGF-beta pathway, and the binding energy of TGF-beta1 was 29.82 kJ/mol. The in vitro experiment further showed that quercetin significantly suppressed fibrosis in TGF-beta and hypoxia treated HK2 cells in a dose dependent manner by inhibiting TGF-beta/Smad3 pathway. Conclusion(s): Quercetin could attenuate renal fibrosis in patients with COVID-19 by suppressing TGF-beta/Smad3 pathway. No conflict of interestCopyright © 2023

Immunoglobulin M (IgM) Inhibits Replication of SARS-CoV-2 In Vero E6 Cells In Vitro and Delays Disease in K18-hACE2 Mice Infected with SARSCoV-2 In Vivo

Purpose: To determine if IgM has a direct effect in preventing SARS-CoV-2 replication in Vero E6 cells, and delaying or preventing disease in infected K18- hACE2 mice. Method(s): 1) Vero E6 cells, grown to confluence in 12 well plates, were used to test the effect of IgM in reducing the number of plaque-forming units (PFU).There were 4 groups: a) 25PFU WA-1 SARS-CoV-2 was combined with 20, 5 or 0.8mug IgM in growth medium, and incubated for 1hr in a final volume of 500ul. 100mul was added to Vero E6 cells in replicate wells and incubated for 1hr;b) 100mul of 20, 5 or 0.8mug IgM was added to Vero E6 cells and incubated. Media was aspirated and the cells were then inoculated with 25PFU WA-1 and incubated for 1hr;c) Virus control - as above, but with no IgM;d) No virus or IgM. FBS growth medium containing Avicel was overlain in the wells and incubated for 48 hours. Virus replication was stopped by incubating with 10% buffered formalin. Following removal of formalin, plates were stained with Giemsa violet, dried, and photographed. 2) A COVID -19 Spike- ACE2 binding assay kit was used to determine if IgM (2ug, 4.5ug, 20ug, 45ug IgM) inhibits the interaction between the Spike-receptor binding domain (S-RBD) and Angiotensin I ConvertingEnzyme 2 (ACE2) receptor. 3) K18-hACE2 mice were divided into 3 groups based on treatment regimen;Group 1: with IgM, No virus;2: with Saline, with virus;3: with IgM, with virus. 35ug IgM was injected intraperitoneal in a single dose, 2 days prior to infection. Mice were innoculated intranasally with 1250 pfu of HK SARS-CoV-2. Result(s): 1) Exposure of 25PFU SARS-CoV-2 to IgM (at all concentrations) prior to incubation with Vero E6 cells, inhibited its replication in Vero E6 cells. When Vero E6 cells were incubated with IgM prior to infection, no plaques were seen in wells with 20ug and 5ug IgM but were observed in wells with 0.8ug IgM. Plaques were also observed in the Virus alone group, but none were seen in the 'No IgM-No virus' group. 2) 45ug IgM/100uls inhibited the binding of S-RBD to ACE2 by ~94-100%, 20ug IgM/100uls inhibited it by ~80%, and 2 or 4.5ug/100ul by ~70-75%. Control without IgM did not inhibit the S-RBD-ACE-2 binding. 3) Pretreatment with a single low dose IgM injection delayed weight loss and mortality. Conclusion(s): IgM inhibits the replication of SARS-CoV-2 in Vero cells in vitro. It also inhibits the interaction between S-RBD that is present on the viral surface and the ACE2 receptor, by binding to S-RBD. A single low dose of IgM given prechallenge delayed disease in infected mice. The discovery that IgM interferes with the formation of the S-RBD-ACE2 complex, and that a single low dose can delay disease, indicates its translational potential as a vaccine/therapeutic to prevent or treat COVID-19.

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

EXPERIENCE IN THE TREATMENT OF HAIRY CELL LEUKEMIA IN KAZAKHSTAN

Background: Hairy cell leukemia is a rare oncohematological disease that manifests itself in damage to the bone marrow and spleen. One of the characteristic changes in the bone marrow are large cells, a rounded nucleus and thin outgrowths - 'hairs' of the cytoplasm. The standard of care are drugs: cladribine and purine analogues-pentostatin. The complexity of therapy lies in the high risk of infections due to prolonged cytopenia during therapy. Aims: The aim of the study was to analyze the detection of hairy cell leukemia in Kazakhstan and the effectiveness of the cladribine regimen. Methods: In Kazakhstan 30 patients were diagnosed over the last 5-year period. All patients underwent cytological, histological examination of the bone marrow, bone marrow immunophenotyping. Thirty patient s were treated with cladribine intravenous infusion 0.1 mg/kg per day for 7 days. The average age was 54.6years (from 29 to 80 years), men-10, women-20. With a median follow-up of 4 years, the complete response (CR) was -25 patients, progression of disease - 3 patients, two patients die from infection. Results: Median duration of response was 38 months (range, 0.0+ to 52.0+). Median overall survival was not reached in all patients with CR. All patients had hematological complications in the form of grade 4 leukopenia - 30 patients, grade 4 thrombocytopenia - 28 patients, grade 3 thrombocytopenia - 2, patients grade 2 anemia - 9 patients. Emetic syndrome in the form of vomiting of the 3rd degree was in one patient, diarrhea of the 2nd degree in one patient. Eleven patients had febrile neutropenia. Two patients had a fatal outcome due to the development of pneumonia and subsequent sepsis. Summary/Conclusion: Treatment of patients with hairy cell leukemia with a purine analogue showed high efficiency, but was accompanied by prolonged cytopenia and frequent secondary infection. It is necessary to consider the issue of vaccination of this category of patients with anti-pneumococcal vaccine and also to conduct continuous monitoring. Ten patients with CR were vaccinated against coronavirus infection.

COVID-19 in a Hairy Cell Leukemia Patient: A Rare Case Report.

The detailed clinical course of coronavirus disease 2019 (COVID-19) in patients with hairy cell leukemia (HCL) is rarely reported. We report the first case of HCL diagnosed with prolonged pancytopenia after COVID-19 infection in Japan. We describe the case of a 56-year-old man who was diagnosed with COVID-19. Computed tomography revealed ground-glass opacities in the bilateral lung lobes as well as splenomegaly. Remdesivir and dexamethasone were administered for the treatment of COVID-19. Since the pancytopenia persisted, bone marrow examination was performed, and he was diagnosed with HCL. Although pancytopenia can occur with COVID-19 alone, clinicians should be alerted regarding the presence of hematologic malignancies in patients in whom pancytopenia persists after COVID-19 treatment or in those with splenomegaly. Further, the condition of all previously reported patients with COVID-19 associated with HCL was severe enough to require mechanical ventilation. This is the first case in which the disease was not severe. The interleukin-6 (IL-6) level was lower in this case than in previous cases, suggesting that racial differences in IL-6 production may have contributed to COVID-19 severity.

Concurrent COVID-19 and pneumocystis carinii pneumonia in a patient subsequently found to have underlying hairy cell leukemia.

SARS-CoV-2 infection manifestation has great diversity and it becomes even greater while co-infection occurs or there is a serious underlying disease in an affected patient. In this case report, we present a case of a 71-year-old man who underwent a chest CT scan following the development of fever, weakness, and pulmonary symptoms. Chest CT scan showed segmental consolidation with centrilobular nodular infiltration, ground glass opacifications in the inferior segment of the left upper and lower lobes, and left lung pleural thickening which was atypical for either COVID-19 infection or pneumocystis carinii pneumonia but his SARS-CoV-2 PCR result was positive and he received COVID-19 treatment. His symptoms recurred after a few months with the same chest CT findings and subsequent bronchoalveolar lavage revealed the presence of pneumocystis carinii infection. Consequently, he received cotrimoxazole which caused improvement in symptoms, nonetheless splenomegaly and anemia remained in his clinical and laboratory investigation. Accordingly, bone marrow study and flow cytometry was done and confirmed the previously undiagnosed hairy cell leukemia. This case accentuates the fact that when we face atypical clinical or paraclinical features in a COVID-19 patient, we should explore for coinfection or unknown underlying diseases.

Prompt Hematological Recovery in Response to a Combination of Pegylated Interferon α-2a and Rituximab in a Profoundly Immuno-Suppressed Hairy Cell Leukemia Patient with a Mycobacterial Infection at Onset: Benefits and Drawbacks of Rapid Immune Reconstitution.

The present paper reports, to the best of our knowledge for the first time, the efficacy and tolerability of the combination of interferon (IFN)α-2a in pegylated formulation and rituximab after a "priming" phase with IFN in the frontline treatment of hairy cell leukemia (HCL) in a profoundly immunosuppressed patient with a Mycobacterium abscessus infection at onset. This immunotherapy combination may represent a potential therapeutic option in patients with active severe infection and for whom the use of purine nucleoside analogues (PNA) is contraindicated. The benefits and drawbacks of remarkably rapid immune reconstitution in the context of opportunistic infections are highlighted as well, as the potentially paradoxical effects of immune recovery as a result of effective immunotherapy strategies, known as immune reconstitution inflammatory syndrome (IRIS), have to be taken into account when dealing with patients with opportunistic infections.

Immune reconstitution in patients with classical hairy cell leukemia during BRAF inhibitor treatment

For patients with classical hairy cell leukemia (HCL) standard treatment options such as purine analogues (PA) achieve a durable response, but are associated with severe immunosuppression. In particular, PAs cause long-lasting depletion of CD4+-lymphocytes. The BRAF inhibitor vemu-rafenib is effective in HCL but its use in first line treatment is currently limited to select clinical situations such as active infection. There is a lack of clinical data on the impact of BRAF inhibitors on immune function or response to vaccines in HCL. Here, we report the use of vemurafenib in four patients with HCL during the coronavirus disease 2019 (COVID-19) pandemic with detailed immune monitoring during treatment. All patients responded to BRAFi with normalization of peripheral blood counts. None of the patients developed neutropenia or severe infection. We observed stable CD4+ and CD8+ T-lymphocyte counts while receiving vemurafenib (median treatment duration 131 days). Immunoglobulin levels were normal in all patients without decline. 3 out of 4 patients received the SARS-CoV-2 vaccination (Pfizer-BioNTech) during vemuraf-enib treatment. The IgG antibody levels against the spike-protein of SARS-CoV-2 were detectable in 3 out of 3 patients (2-12 weeks after the second vaccination). Our findings suggest that BRAF inhibitors have limited effect on cellular and humoral immune function. The findings may support the use of BRAF inhibitors during the current pandemic to avoid the potentially detrimental effects of PA and thus minimize COVID-19 related morbidity and mortality in patients without SARS-CoV-2 vaccination.

Diagnosis and treatment of hairy cell leukemia as the COVID-19 pandemic continues.

Hairy cell leukemia (HCL) is an indolent B-cell malignancy, usually driven by the BRAF V600E mutation. For 30 years, untreated and relapsed HCL was successfully treated with purine analogs, but minimal residual disease (MRD) remained in most patients, eventually causing relapse. Repeated purine analogs achieve decreasing efficacy and increasing toxicity, particularly to normal T-cells. MRD-free complete remissions (CRs) are more common using rituximab with purine analogs in both 1st-line and relapsed settings. BRAF inhibitors and Ibrutinib can achieve remission, but due to persistence of MRD, must be used chronically to prevent relapse. BRAF inhibition combined with Rituximab can achieve high MRD-free CR rates. Anti-CD22 recombinant immunotoxin moxetumomab pasudotox is FDA-approved in the relapsed setting and is unique in achieving high MRD-free CR rates as a single-agent. Avoiding chemotherapy and rituximab may be important in ensuring both recovery from COVID-19 and successful COVID-19 vaccination, an area of continued investigation.

A Rare Case of Hairy Cell Leukemia with Unusual Loss of CD123 Associated with COVID-19 at the Time of Presentation.

Coronavirus disease 2019 (COVID-19) pandemic has been a serious threat and has been reported with different presentations and complications. Older age, along with comorbidities such as diabetes, hypertension, or cardiac disease, increases the risk factors for COVID-19 severity and death [N Engl J Med. 2020;382(18):1708-20 and Lancet Respir Med. 2020 05;8(5):475-81]. It is proposed that cancer patients have a significantly higher incidence of severe incidents including admission to the intensive care unit, the necessity for assisted ventilation, and even death after catching the virus compared with non-cancer patients [Lancet Oncol. 2020;21(3):335-7]. It is also described that cancer patients appear to be twice as likely to contract infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) [JAMA Oncol. 2020;6(7):1108-10]. Hairy cell leukemia (HCL) is a rare B-cell lymphoproliferative disorder, with patients typically presenting with cytopenias, marked splenomegaly in 80-90% of patients, circulating leukemia cells, bone marrow infiltration and the presence of BRAF V600E somatic mutation [Indian J Hematol Blood Transfus. 2014;30(Suppl 1):413-7]. Leukemic cells classically have central nuclei and abundant cytoplasm with hairy-like projections and express CD11c, CD25, CD103, and CD123 [Indian J Hematol Blood Transfus. 2014;30(Suppl 1):413-7]. Loss of CD123 in HCL has been rarely reported in the literature [Am J Hematol. 2019;94(12):1413-22]. We describe a unique case of a COVID-19-positive male who presented with severe respiratory symptoms, deteriorated quickly, and was intubated. Workup of severe progressive pancytopenia and bone marrow examination revealed HCL without splenomegaly and with atypical unusual loss of CD123. To our knowledge, this is the first case of CD123-negative HCL without splenomegaly associated with COVID-19 infection as the initial presentation.