Flow Cytometry of CD5-Positive Hairy Cell Leukemia.

BACKGROUND AND OBJECTIVE: Hairy cell leukemia (HCL) is a chronic lymphoproliferative disorder for which diagnosis is typically straightforward, based on bone marrow morphology and flow cytometry (FC) or immunohistochemistry. Nevertheless, variants present atypical expressions of cell surface markers, as is the case of CD5, for which the differential diagnosis can be more difficult. The aim of the current paper was to describe diagnosis of HCL with atypical CD5 expression, with an emphasis on FC. METHODS: The detailed diagnostic methodology for HCL with atypical CD5 expression is presented, including differential diagnosis from other lymphoproliferative diseases with similar pathologic features, by FC analysis of the bone marrow aspirate. RESULTS: Diagnosis of HCL by means of FC started by gating all events based on side scatter (SSC) versus CD45 and B lymphocytes were selected from the lymphocytes gate as CD45/CD19 positive. The gated cells were positive for CD25, CD11c, CD20, and CD103, while CD10 proved to be dim to negative. Moreover, cells positive for CD3, CD4, and CD8, the three pan-T markers, as well as CD19, showed a bright expression of CD5. The atypical CD5 expression is usually correlated with a negative prognosis and thus chemotherapy with cladribine should be initiated. CONCLUSION: HCL is an indolent chronic lymphoproliferative disorder and diagnosis is usually straightforward. However, atypical expression of CD5 renders its differential diagnosis more difficult, but FC is a useful tool that allows an optimal classification of the disease and allows initiation of timely satisfactory therapy.

Correlation between the prevalence of T-cell lymphomas and alcohol consumption.

BACKGROUND AND AIMS: Alcohol is a psychoactive substance that causes dependence, with many thousands of years in the history of mankind, being widely used in different cultures. According to the International Agency for Research on Cancer, alcohol is involved in the development of cancer, being directly associated with it. Considering that alcohol is involved in the initiation and dissemination of gastrointestinal malignancies, the objective of the study was to assess its role in the pathogenesis of T-cell lymphomas, as well as its possible correlation with chronic consumption. METHODS: The patient cohort was compiled from the Sixth Medical Center of the People's Liberation Army Navy General Hospital in Beijing, China. A total of 30 patients matched the criteria and were enrolled in the study. Statistical analysis of the raw data was performed using R Statistics version R 3.5.1. released on the 29.08.2018. RESULTS: Our data demonstrate that the most common extranodal involvment of T-cell lymphoma patients is represented in decreasing order by bone marrow, peritoneum, rhino-oropharynx and the liver-biliary system. Nodal involvement is mainly represented in decreasing order by the laterocervical, axillary, mediastinal and inguinal regions. CONCLUSIONS: These findings may be of value in further research and practical/clinical settings. Fever is the most common clinical feature and was present in most studied patients.

Identification of a novel WAS mutation in a South African patient presenting with atypical Wiskott-Aldrich syndrome: a case report.

BACKGROUND: The X-linked recessive primary immunodeficiency disease (PIDD) Wiskott-Aldrich syndrome (WAS) is identified by an extreme susceptibility to infections, eczema and thrombocytopenia with microplatelets. The syndrome, the result of mutations in the WAS gene which encodes the Wiskott-Aldrich protein (WASp), has wide clinical phenotype variation, ranging from classical WAS to X-linked thrombocytopaenia and X-linked neutropaenia. In many cases, the diagnosis of WAS in first affected males is delayed, because patients may not present with the classic signs and symptoms, which may intersect with other thrombocytopenia causes. CASE PRESENTATION: Here, we describe a three-year-old HIV negative boy presenting with recurrent infections, skin rashes, features of autoimmunity and atopy. However, platelets were initially reported as normal in numbers and morphology as were baseline immune investigations. An older male sibling had died in infancy from suspected immunodeficiency. Uncertainty of diagnosis and suspected severe PIDD prompted urgent further molecular investigation. Whole exome sequencing identified c. 397 G > A as a novel hemizygous missense mutation located in exon 4 of WAS. CONCLUSION: With definitive molecular diagnosis, we could target treatment and offer genetic counselling and prenatal diagnostic testing to the family. The identification of novel variants is important to confirm phenotype variations of a syndrome.

Differential Diagnosis of Malignant Lymphadenopathy Using Flow Cytometry on Fine Needle Aspirate: Report on 269 Cases.

INTRODUCTION: Fine needle aspiration (FNA) is frequently the first noninvasive test used for the diagnostic workup of lymphadenopathy. There have been many studies showing its usefulness, especially in conjunction with other techniques for the diagnosis of lymphoma, but it remains inferior to histological examination. The data regarding this subject have mostly been reported mostly from first-world countries, but are scarce for emerging economies. Thus, the current study assesses the agreement between fine needle aspiration flow cytometry (FNA FC) and histology in the aforementioned region. MATERIAL AND METHODS: We conducted a retrospective study including the FNA FC adenopathy diagnoses made between January 2011 and December 2016 at the Tygerberg Hospital, Cape Town, South Africa. Additional variables included were the histological diagnosis, sex and age of the included patients. RESULTS: In the descriptive part of the current study, 269 FNA FC samples were included. The most frequent diagnoses made on these were represented by B-cell lymphoma, reactive adenopathy, no abnormality detected (NAD), and non-hematological malignancy. In the analytical part of the current study, there were 115 cases included that had both valid FNA FC and histological diagnoses. It could be observed that FNA FC can correctly diagnose B-cell lymphoma in most cases, but it is a poor diagnostic tool especially for Hodgkin lymphoma in this setting as only a four-color flow cytometer was available for diagnosis. Moreover, FNA FC diagnosis of reactive adenopathy and of no abnormalities detected was shown to frequently hide a malignant disease. CONCLUSION: In countries with scarce resources, FNA FC represents a useful diagnostic tool in the case of B-cell lymphoma, but may misdiagnose reactive adenopathy. Thus, FNA FC should be used in a case-specific manner, in addition to as a screening tool, with the knowledge that in cases with a high clinical suspicion of lymphoma, histological diagnosis is a necessity.

Apoptotic resistance in chronic lymphocytic leukemia and therapeutic perspectives.

Increased resistance to apoptosis represents a key oncogenic mechanism in chronic lymphocytic leukemia (CLL) that has been attributed to the upregulation of the anti-apoptotic B cell lymphoma 2 (Bcl-2) family members. Such an observation was associated with the development of molecules inhibiting Bcl-2 activity, and among them, BH3-mimetics represent a novel class of therapeutic compounds. In 2016, venetoclax became the first approved oral inhibitor of Bcl-2, and it has been used with success in patients with CLL who present with a 17p deletion or TP53 mutations and in those who have received at least one prior therapy. However, its mechanism for controlling relapses, and its optimal use in terms of duration and combinations with other drugs, remain unknown. Therefore, this review focuses on the mechanisms controlling apoptosis, CLL B cell strategies to prevent apoptosis including in response to BH3-mimetics, and arguments supporting the use of BH3-mimetics in association with other therapies in order to limit compensatory mechanisms.

Use of flow cytometry in the phenotypic diagnosis of hodgkin's lymphoma.

Hodgkin's lymphoma (HL) has a unique immunophenotype derived from immunohistochemistry (positive for CD15, CD30, and Pax-5; negative for CD3, CD20 in most cases, and CD45). The knowledge gained over recent years enables better diagnosis, prognosis, and treatment of HL. Flow cytometry as a tool for the diagnosis of classic HL has not been useful in the past due to the difficulty in isolating Reed-Sternberg cells as they are admixed in a rich inflammatory background which consists mainly of T cells, B cells, eosinophils, histiocytes, and plasma cells. However, in the recent past, several studies have tried to identify Reed-Sternberg cells using flow cytometry on fine needle aspiration or tissue biopsy of lymph nodes to confirm or supplement immunohistochemistry staining in diagnosis. Newer and more sensitive tools such as flow cytometry can be used for diagnosis, technology that may have been difficult in the past for diagnosis of this lymphoma subtype. Using flow cytometry, diagnosis is faster and could lead to point-of-care technology especially where we have typical immunophenotype signatures. © 2018 International Clinical Cytometry Society.

Mesenchymal stem cells in myeloproliferative disorders - focus on primary myelofibrosis.

Primary myelofibrosis (PMF) is the most aggressive Philadelphia-negative (Ph-) myeloproliferative neoplasm (MPN), characterized by bone marrow (BM) insufficiency, myelofibrosis (MF), osteosclerosis, neoangiogenesis, and extramedullary hematopoiesis (EMH) in spleen and liver. Presently, there is no curative treatment for this disease and therapy consists primarily of symptom relief and, in selected cases, allogeneic hematopoietic stem cell transplant (alloHSCT). PMF's major defining characteristics, as well as several recently described aspects of its cellular and molecular pathophysiology all support a critical role for dysregulated cell-cell/cell-extracellular matrix interactions and cytokine/chemokine signaling within the BM niche in the natural history of this disease. This review will highlight current data concerning the involvement of the BM niche, particularly of mesenchymal stem cells (MSC), in PMF, and will then discuss the rationale for a stroma-directed treatment, and the advantages such an approach would offer over the current treatments focused on targeting the malignant clone.

Castleman's disease in the HIV-endemic setting.

INTRODUCTION: Castleman's disease (CD), first described by Benjamin Castleman in 1954, is a giant or angiofollicular lymph node hyperplasia, described as a rare monotypic polyclonal B-cell lymphoproliferative disorder with an incompletely understood pathogenesis and variable clinical behavior. This study aimed to determine the incidence of CD diagnosis over an 11-year period. Additionally, the study aimed to describe the demographic, laboratory, and pathological features of CD. METHODS: This is a retrospective study where the demographic and laboratory data were retrieved from the Tygerberg Academic Hospital (TAH) patient electronic records and Tygerberg Lymphoma Study Group (TLSG) and statistical analysis performed on the patients diagnosed with CD. RESULTS: Fifty-four patients were diagnosed with CD during this period. The median age at presentation was 39 years (range: 9-58). HIV serology was available in 53 patients, of which 51 were HIV-positive and two were HIV-negative. The history of initiation of antiretroviral therapy at diagnosis was available in 43 patients (38 on treatment, four were not on treatment, and one defaulted treatment). The median CD4 count was 232.50 cells/µL (range: 2-883). The HIV viral load was performed in 43 patients at diagnosis, which was <49 HIV-1 RNA copies/µL in more than half of the patients (58%). Diagnosis was made on lymph node biopsies in 53 patients, with one case diagnosed on a spleen biopsy. Kaposi sarcoma was found on the same tissue biopsy in 13 cases. A bone marrow biopsy was performed in 31 patients. The predominant features noted were a disorganized hypercellular marrow with plasmocytosis. CONCLUSION: CD is a rare polyclonal B-cell lymphoproliferative disorder. However, we demonstrated a significant increase in the incidence of HIV-associated multicentric CD over the last decade in our area in South Africa.

Minimal residual disease in chronic lymphocytic leukemia: A consensus paper that presents the clinical impact of the presently available laboratory approaches.

Chronic lymphocytic leukemia (CLL) is a malignancy defined by the accumulation of mature lymphocytes in the lymphoid tissues, bone marrow, and blood. Therapy for CLL is guided according to the Rai and Binet staging systems. Nevertheless, state-of-the-art protocols in disease monitoring, diagnostics, and prognostics for CLL are based on the assessment of minimal residual disease (MRD). MRD is internationally considered to be the level of disease that can be detected by sensitive techniques and represents incomplete treatment and a probability of disease relapse. MRD detection has been continuously improved by the quick development of both flow cytometry and molecular biology technology, as well as by next-generation sequencing. Considering that MRD detection is moving more and more from research to clinical practice, where it can be an independent prognostic marker, in this paper, we present the methodologies by which MRD is evaluated, from translational research to clinical practice.

The role of the pathology department in the preanalytical phase of molecular analyses.

After introducing the new molecules for the treatment of patients with tumoral pathology, the therapeutical decision will be taken depending on the molecular profile performed upon the harvested tissues. This major modification makes the molecular and morphological analysis an essential part in the clinical management of patients and the pathologist plays an important role in this process. The quality and reproducibility of the results are imperative today and they depend on both the reliability of the molecular techniques and the quality of the tissue we use in the process. Also, the genomics and proteomics techniques, used increasingly often, require high-quality tissues, and pathology laboratories play a very significant role in the management of all phases of this process. In this paper the parameters which must be followed in order to obtain optimal results within the techniques which analyze nucleic acids and proteins were reviewed.

Hodgkin's lymphoma and its association with EBV and HIV infection.

Hodgkin's lymphoma (HL) constitutes a clonal expansion of what appears to be malignant B cells. Viruses are involved in its pathogenesis, such as the Epstein-Barr virus (EBV) and human immunodeficiency virus (HIV). Since these viral infections have been shown to play key roles in the pathogenesis of HL, countries with a prevalence of HIV and EBV represent interesting population targets to study the pathogenesis of HL, linking the evolution of the disease with viral infections. Usually, patients present with late stage disease often involving the bone marrow at the time of diagnosis. The present paper discusses the role of viral infection in African countries, as HL is considered to be a malignant disease characterized by an inflammatory reaction to an aberrant B cell clone that is well known as the Reed-Sternberg cell (HRS).

Proceedings from the 1st Insights in Hematology Symposium, Cluj-Napoca, Romania March 11-12, 2016.

In the March 2016 issue of the Lancet Haematology, the editorial office published a paper stating the roadmap for European research in hematology, based on the European Hematology Association (EHA) consensus document that outlines the directions in hematology for the following years across the continent. The meeting entitled "Insights in hematology" is organized a support for the initiative of a roadmap for European hematologists regarding research, may it be basic research or clinical research, but this consensus should not be focused mainly on European institutions, but rather form the backbone of global research between Europe and the United States, Japan or any other country. This will allow Europeans to learn as well as to share their experience with the rest of the scientific and medical community. And the Cluj-Napoca meeting should be followed by other such meetings all across the EU.

The role of microRNAs in the pathogenesis of HIV-related lymphomas.

The incidence of HIV-related lymphomas (HRLs) is increased by 60-100 times in patients with HIV. When compared to the general population, patients with HRLs often present with extranodal lymphoid proliferation, most frequently of the gastrointestinal tract, central nervous system, liver and bone marrow. MicroRNAs (miRs) are non-coding double-stranded RNA molecules of 18-25 nucleotides that regulate post-translational gene expression by inhibiting translation or promoting degradation of messenger RNA complementary sequences. Before their discovery, tumorigenesis was thought to have been caused by the alteration of protein-coding oncogenes and tumor-suppressor genes, but once identified in B-cell chronic lymphocytic leukemia, miRs function as either oncogenes or tumor-suppressor genes was confirmed in different types of malignancies. Since miRs are clearly involved in tumorigenesis in many cancers, their role in HRLs is now receiving attention. A few studies have been conducted thus far in some HRLs on the involvement of miR in the pathogenesis of lymphoid malignancies. Since B-cell lymphomas arise from various stages of B-cell development in both HIV-infected and HIV-naïve patients, investigators have tried to determine the different miR signatures in B-cell development. As classic immunohistochemistry staining is sometimes not enough for the differential diagnosis of HRLs, in the present review, we have described the potential use of miRs in the prognosis and diagnosis of these diseases.

Challenges of biobanking in South Africa to facilitate indigenous research in an environment burdened with human immunodeficiency virus, tuberculosis, and emerging noncommunicable diseases.

The high burden of infectious diseases and the growing problem of noncommunicable and metabolic disease syndromes in South Africa (SA) forces a more focused research approach to facilitate cutting-edge scientific growth and public health development. Increased SA research on these diseases and syndromes and the collection of associated biospecimens has ensured a plethora of biobanks created by individuals, albeit without the foresight of prospective and collective use by other local and international researchers. As the need for access to high-quality specimens in statistically relevant numbers has increased, so has the necessity for the development of national human biobanks in SA and across the Continent. The prospects of achieving sustainable centralized biobanks are still an emerging and evolving concept, primarily and recently driven by the launch of the H3Africa consortium, which includes the development of harmonized and standardized biobanking operating procedures. This process is hindered by a myriad of complex societal considerations and ethico-legal challenges. Efforts to consolidate and standardize biological sample collections are further compromised by the lack of full appreciation by national stakeholders of the biological value inherent in these collections, and the availability of high quality human samples with well-annotated data for future scientific research and development. Inadequate or nonexistent legislative structures that specifically regulate the storage, use, dispersal, and disposal of human biological samples are common phenomena and pose further challenges. Furthermore, concerns relating to consent for unspecified future uses, as well as access to information and data protection, are all new paradigms that require further consideration and public engagement. This article reviews important fundamental issues such as governance, ethics, infrastructure, and bioinformatics that are important foundational prerequisites for the establishment and evolution of successful human biobanking in South Africa.