COVID-19-Induced Hyperleucocytosis in Chronic Lymphocytic Leukaemia.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus responsible for the current global pandemic, coronavirus disease 2019 (COVID-19). COVID-19 usually presents with respiratory symptoms but can affect multiple organ systems. A wide spectrum of complications can occur depending upon the comorbidities of patients. There is limited literature available regarding the presentation and outcome of COVID-19 in chronic lymphocytic leukaemia (CLL) patients. We report 2 cases of COVID-19-induced hyperleucocytosis (WBC count >100,000/µl) in CLL patients. LEARNING POINTS: Lymphopenia has been associated with severe disease and is a poor prognostic factor in COVID-19 infected patients; however, our cases show COVID-19-induced hyperleucocytosis (WBC count >100,000/µl)/lymphocytosis in CLL patients.Prior reports suggest that ibrutinib may have a protective effect against COVID-19 by decreasing inflammation and preventing progression to ARDS.

COVID-19 in a Patient with Chronic Lymphocytic Leukaemia with Pseudohypoxemia.

Infection with SARS-CoV-2 causes critical disease in approximately 5% of affected patients, particularly the elderly, hypertensive, obese and immunocompromised. Patients with haematological cancer, including chronic lymphocytic leukaemia (CLL), are particularly at risk of complications. Very rarely, patients with extreme leukocytosis may develop spurious hypoxemia, or pseudohypoxemia, which confuses the diagnosis of complications and can lead to intervention errors. We report the case of a patient with CLL, severe infection with SARS-CoV-2 and pseudohypoxemia. LEARNING POINTS: Patients with haematological neoplasms are susceptible to viral, bacterial and fungal infections, and are thus at risk of COVID-19.Patients with chronic lymphocytic leukaemia may rarely, due to a high lymphocyte count, present with spurious, or in vitro, hypoxemia.The clinician must identify and properly treat such cases to prevent any unnecessary treatments and their complications.

Immune correlates of protection by vaccine against SARS-CoV-2 in patients with chronic lymphocytic leukaemia.

In chronic lymphocytic leukaemia (CLL) the efficacy of SARS-CoV-2 vaccination remains unclear as most studies have focused on humoral responses. Here we comprehensively examined humoral and cellular responses to vaccine in CLL patients. Seroconversion was observed in 55.2% of CLL with lower rate and antibody titres in treated patients. T-cell responses were detected in a significant fraction of patients. CD4+ and CD8+ frequencies were significantly increased independent of serology with higher levels of CD4+ cells in patients under a Bruton tyrosine kinase (BTK) or a B-cell lymphoma 2 (BCL-2) inhibitor. Vaccination skewed CD8+ cells towards a highly cytotoxic phenotype, more pronounced in seroconverted patients. A high proportion of patients showed spike-specific CD4+ and CD8+ cells producing interferon gamma (IFNγ) and tumour necrosis factor alpha (TNFα). Patients under a BTK inhibitor showed increased production of IFNγ and TNFα by CD4+ cells. Vaccination induced a Th1 polarization reverting the Th2 CLL T-cell profile in the majority of patients with lower IL-4 production in untreated and BTK-inhibitor-treated patients. Such robust T-cell responses may have contributed to remarkable protection against hospitalization and death in a cohort of 540 patients. Combining T-cell metrics with seroprevalence may yield a more accurate measure of population immunity in CLL, providing consequential insights for public health.

Expression of BCL11A in chronic lymphocytic leukaemia.

INTRODUCTION: The B-cell lymphoma/leukaemia 11A (BCL11A) gene encodes a Krüppel-like transcription factor involved in lymphocyte development during normal haematopoiesis. Aberrant expression of BCL11A has been observed in several haematological malignancies, including chronic lymphocytic leukaemia (CLL). However, its functions in the regulatory networks of malignant B lymphocytes are poorly understood, as are the relations to clinical course and outcome of B-cell malignancies, particularly CLL. METHODS: The expression of BCL11A was analysed in peripheral blood mononuclear cells of 87 newly-diagnosed CLL patients by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR), and association with clinical and molecular variables was assessed. RESULTS: BCL11A was significantly overexpressed in CLL samples compared to control samples (p < 0.001). BCL11A expression level exhibited no association with age, sex, leukocyte, lymphocyte and platelet counts, haemoglobin level, serum ß2-microglobulin, CD38 status and cytogenetic abnormalities. On the other hand, high BCL11A expression was associated with low serum lactate dehydrogenase (p = 0.031), Binet A stage (p = 0.047) and mutated IGHV (p = 0.028). In addition, a positive correlation with BCL2/BAX mRNA ratio was observed (r = 0.36; p < 0.001). Regarding the association with the time to first treatment (TTFT), a trend towards longer median TTFT in BCL11A high- versus BCL11A low-expressing cases was detected (21 vs. 6 months; p = 0.164). CONCLUSION: The results of this study show that BCL11A is upregulated in CLL patients, and that high BCL11A expression at diagnosis may be associated with better prognosis. These data are consistent with the role of BCL11A expression in CLL biology, and imply its potential prognostic relevance.

Effect of miR-221-3p targeting TIMP-2 on proliferation and apoptosis of vascular smooth muscle cells in abdominal aortic aneurysm

Objective: To investigate the effects of miR-221-3p on the proliferation and apoptosis of vascular smooth muscle cells (VSMC) in abdominal aortic aneurysm (AAA) by targeting tissue inhibitor of metalloproteinase- 2 (TIMP-2).

Spontaneous remission of chronic lymphocytic leucemia in a patient with SARS-CoV2.

Although novel therapies have improved the treatment outcome of patients, chronic lymphocytic leukaemia (CLL) is still considered incurable. Recently, a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), causing coronavirus disease 2019 (Covid 19), emerged in late 2019, and it has posed a global health threat. In a limited number of cases, it has been shown that some lymphoma types spontaneously regress after SARS-CoV2 infection suggesting that the infection can trigger de immune system against the tumour cell. Cross-reactivity of pathogen-specific T cells with tumour antigens and natural killer cell activation can be the possible mechanism of this hypothesis.

The role of Bruton's tyrosine kinase in the immune system and disease.

Bruton's tyrosine kinase (BTK) is a TEC kinase with a multifaceted role in B-cell biology and function, highlighted by its position as a critical component of the B-cell receptor signalling pathway. Due to its role as a therapeutic target in several haematological malignancies including chronic lymphocytic leukaemia, BTK has been gaining tremendous momentum in recent years. Within the immune system, BTK plays a part in numerous pathways and cells beyond B cells (i.e. T cells, macrophages). Not surprisingly, BTK has been elucidated to be a driving factor not only in lymphoproliferative disorders but also in autoimmune diseases and response to infection. To extort this role, BTK inhibitors such as ibrutinib have been developed to target BTK in other diseases. However, due to rising levels of resistance, the urgency to develop new inhibitors with alternative modes of targeting BTK is high. To meet this demand, an expanding list of BTK inhibitors is currently being trialled. In this review, we synopsize recent discoveries regarding BTK and its role within different immune cells and pathways. Additionally, we discuss the broad significance and relevance of BTK for various diseases ranging from haematology and rheumatology to the COVID-19 pandemic. Overall, BTK signalling and its targetable nature have emerged as immensely important for a wide range of clinical applications. The development of novel, more specific and less toxic BTK inhibitors could be revolutionary for a significant number of diseases with yet unmet treatment needs.

Serological SARS-CoV-2 antibody response, potential predictive markers and safety of BNT162b2 mRNA COVID-19 vaccine in haematological and oncological patients.

Haemato-oncological patients are at risk in case of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Currently, vaccination is the best-evaluated preventive strategy. In the present study, we aimed to assess serological response, predictive markers, and safety of BNT162b2 in haemato-oncological patients. A total of 259 haemato-oncological patients were vaccinated with two 30 µg doses of BNT162b2 administered 21 days apart. Serological response was assessed by ELECSYS® Anti-SARS-CoV-2-S immunoassay before vaccination, and at 3 and 7 weeks after the first dose (T1, T2). Safety assessment was performed. At T2 spike protein receptor binding domain (S/RBD) antibodies were detected in 71·4% of haematological and in 94·5% of oncological patients (P < 0·001). Haematological patients receiving systemic treatment had a 14·2-fold increased risk of non-responding (95% confidence interval 3·2-63·3, P = 0·001). Subgroups of patients with lymphoma or chronic lymphocytic leukaemia were at highest risk of serological non-response. Low immunoglobulin G (IgG) level, lymphocyte- and natural killer (NK)-cell counts were significantly associated with poor serological response (P < 0·05). Vaccination was well tolerated with only 2·7% of patients reporting severe side-effects. Patients with side-effects developed a higher S/RBD-antibody titre compared to patients without side-effects (P = 0·038). Haematological patients under treatment were at highest risk of serological non-response. Low lymphocytes, NK cells and IgG levels were found to be associated with serological non-response. Serological response in oncological patients was encouraging. The use of BNT162b2 is safe in haemato-oncological patients.