Diversity of leukaemic cell morphology in ATL correlates with prognostic factors, aberrant immunophenotype and defective HTLV-1 genotype

Adult T-Cell Leukemia-Lymphoma Presenting Concurrently with Myelopathy

Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus. Of the approximate ten to twenty million people currently infected worldwide, 4-9% of infected individuals develop adult T-cell leukemia/lymphoma (ATLL) or HTLV-associated myelopathy/tropical spastic paresis (HAM/TSP) in their lifetime. The current report is based on a patient who presented concurrently with CD30+ lymphoma subtype ATLL and HAM/TSP. The patient's ATLL responded to brentuximab-vedotin-based chemotherapy; however, HAM/TSP did not improve. The patient's peripheral blood mononuclear cells were cultured and injected into immunodeficient mice, and the mice developed massive organ involvement and chronic lymphocytic leukemia-subtype ATLL. This case study is novel in the findings of concurrent development of ATLL and HAM/TSP, the response to brentuximab-vedotin chemotherapy, and the use HTLV-1 helix basic zipper protein-targeted probe for RNAscope for diagnosis.

Blocking cholesterol efflux mechanism is a potential target for anti-lymphoma therapy

Cholesterol is an essential plasma membrane lipid for the maintenance of cellular homeostasis and cancer cell proliferation. Free cholesterol is harmful to cells; therefore, excessive free cholesterol must be quickly esterified by acetyl-coenzyme A:cholesterol acetyltransferase (ACAT) and exported by scavenger receptor class B member I (SR-BI) or ATP-binding cassette protein A1 (ABCA1) from specific cells such as macrophage foam cells, which contain cholesteryl ester-derived vacuoles. Many vacuoles are present in the cytoplasm of Burkitt's lymphoma cells. In this study, we observed that these "vacuoles" are often seen in high-grade lymphomas. Cell culture study using lymphoma cell lines found that esterified cholesterol is the main component of these "vacuoles." and the expression of cholesterol metabolism-related molecules was significantly upregulated in lymphoma cell lines, with SR-BI and ACAT inhibitors (BLT-1 and CI-976, respectively) impeding lymphoma cell proliferation. Cytoplasmic free cholesterol was increased by ACAT and SR-BI inhibitors, and the accumulation of free cholesterol induced lymphoma cell apoptosis via inducing endoplasmic reticulum stress. Furthermore, synergistic effects of SR-BI and ACAT inhibitors were observed in a preclinical study. SR-BI inhibitor administration suppressed lymphoma progression in a tumor-bearing mouse model, whereas ACAT inhibitor did not. Therefore, SR-BI inhibitors are potential new antilymphoma therapeutics that target cholesterol metabolism.

HTLV-1 infection in acute t- lymphocytic leukemia/lymphoma

Adult T- lymphocyte leukemia/ lymphoma (ATLL), described by Uchiyama et al. in 1977, is a distinct neoplasia of peripheral T-lymphocytes caused by human T-cell lymphotropic virus type 1 (HTLV-1). The authors describe the case of a 75-year-old female patient who presented with fever, chills, and altered mental status. The peripheral blood morphology showed large atypical lymphocytes with multilobed nuclei and flow cytometry consistent with ATLL. The authors discuss the pathophysiology, differential diagnosis, and subtypes of ATLL in addition to the diagnostic approach using flow cytometry when bone marrow biopsy is not available and modalities of treatment.

Smoldering adult T-cell leukemia complicated with pneumocystis pneumonia: A case report

Adult T-cell leukemia (ATL) is a tumor of CD4-positive T cells that accompanies an infection by human T-cell lymphotropic virus (HTLV-I). ATL is classified into four types—acute, lymphomatous, chronic, and smoldering. Opportunistic infections are known to occur in patients with acute or lymphomatous type ATL; however, whether patients with chronic or smoldering ATL also have a high risk of opportunistic infections is not yet known. Herein, we report a case of pneumocystis pneumonia in a patient with smoldering ATL. He was a 64-year-old man with primary complaints of cough and dyspnea on exertion. A chest radiograph showed infiltration shadows in the left lung field. He was prescribed antibiotics for pneumonia; however, his symptoms worsened, and he developed hypoxemia. White-blood cell count was 13000/μL, and 7% of atypical lymphocytes were found in the smears of peripheral blood cells. His serum β-D glucan concentration was increased to 85.9 pg/mL, and his serum tested positive for anti–HTLV-1 antibody. Chest-computed tomography revealed diffuse ground-glass opacities in the bilateral lung fields. Pneumocystis-polymerase chain reaction performed on bronchoalveolar lavage fluid confirmed pneumocystis, but atypical lymphocytes were not detected via transbronchial lung biopsy. Therefore, he was diagnosed with pneumocystis pneumonia associated with smoldering ATL. Sulfamethoxazole-trimethoprim and corticosteroid therapies were administered to treat the pneumocystis pneumonia, and his symptoms and lung shadows improved rapidly. Thus, opportunistic infections, including pneumocystis pneumonia, may be caused by smoldering ATL. In the case of atypical lymphocyte detection in peripheral-blood smears, clinicians should consider the possibility of ATL.

Evaluating mRNA expression of tax, B chain of PDGF and PDGF-β receptors as well as HTLV-I proviral load in ATL patients and healthy carriers

Adult T-cell leukemia (ATL) is a life-threatening malignant neoplasm of CD4+ T cells resulted from human T-cell leukemia virus type I (HTLV-I). Tax1 protein of HTLV-I can induce malignant proliferation of T-cells by modulating the expression of growth factors such as platelet-derived growth factor (PDGF). Here, we aimed to investigate the proviral load (PVL) of HTLV-I in ATL and also to evaluate the mRNA expression of B chain of PDGF and PDGF-β receptors in ATL patients and HTLV-I-infected healthy carriers. To this end, peripheral blood mononuclear cells (PBMCs) were isolated by using Ficoll-Histophaque density centrifugation. The mean of HTLV-I PVL in ATL patients (42,759 ± 15,737 copies/104 cells [95% CI, 9557-75962]) was significantly (p = .01) higher than that in healthy carriers (650 ± 107 copies/104 cells [95% CI, 422-879], respectively. The HTLV-I PVL in ATL patients exhibited a significant correlation with PBMC count (R = .495, p = .001). The mRNA expression of Tax, B chain of PDGF, and PDGF-β receptor genes was significantly higher in healthy carriers than in patients with ATL. In conclusion, the expression of the canonical PDGFβ and its receptor, and their correlation with Tax expression cannot be a suitable indicator and/or prognostic factor for progression of ATL in HTLV-I carriers.

Adult T-cell leukemia/lymphoma

Summary Adult T-cell leukemia/lymphoma (ATL) is a malignancy of mature CD4+ T-cells caused by human T-cell lymphotropic virus type 1 (HTLV-1). Twenty million people are believed to be infected throughout the world, mostly in Japan, Africa, the Caribbean, and South America, particularly in Brazil and Peru. ATL affects about 5% of infected individuals and is classified in the following clinical forms: acute, lymphoma, primary cutaneous tumoral, chronic (favorable and unfavorable), and smoldering (leukemic and non-leukemic). Although it is considered an aggressive disease, there are cases with a long progression. We emphasize the importance of clinical classification as an indispensable element for evaluating prognosis and appropriate therapeutic approach. Since several cases have been published in Brazil and this disease is still poorly known, we decided to make a review paper for dissemination of clinical, hematological and pathological aspects, diagnosis, and therapy. The best way to reduce the occurrence of ATL would be halting the transmission of the virus through breastfeeding.

Mitotic arrest deficient-like 1 is correlated with poor prognosis in small-cell lung cancer after surgical resection

Mitotic arrest deficient-like 1 (MAD1L1) whose dysfunction is associated with chromosomal instability plays a pathogenic role in a few human cancers. However, the status of MAD1L1 expression in small-cell lung cancer (SCLC) remains unknown. Immunohistochemistry was used to determine the expression of MAD1L1 protein in 32 lymph node metastasis (LN-M) tissues and 88 primary SCLCs compared with 32 adjacent noncancerous tissues. The associations of MAD1L1 protein expression with the clinicopathologic features and clinical outcomes in patients with SCLC were analyzed. The ratio of MAD1L1 positive expression was higher in primary SCLC tissues (39.8 %) and LN-M tissues (46.9 %) compared with adjacent noncancerous tissues (9.4 %). MAD1L1 positive expression was associated with tumor-node-metastasis (TNM) stage (P = 0.003), International Association for the Study of Lung Cancer (IASLC) stage (P = 0.004), tumor size (P = 0.015), lymph node metastasis (P = 0.014), and recurrence (P < 0.001). Multivariate analysis suggested that MAD1L1 positive expression was an independent factor for overall survival (hazard ratio (HR) 2.002; 95 % confidence interval (CI) 1.065-3.763; P = 0.031) and recurrence-free survival (HR 2.263; 95 % CI 1.197-4.276; P = 0.012). To sum up, MAD1L1 positive expression may be associated with tumour progression and metastasis in SCLCs and may thus serve as a new biomarker for prognosis in these patients.

Advanced human T-cell leukemia virus type 1 carriers and early-stage indolent adult T-cell leukemia-lymphoma are indistinguishable based on CADM1 positivity in flow cytometry

We previously reported that the cell adhesion molecule 1 (CADM1) versus CD7 plot in flow cytometry reflects disease progression in human T-cell leukemia virus type 1 (HTLV-1) infection. In CD4⁺ cells from peripheral blood, CADM1⁻CD7⁺ (P), CADM1⁺CD7^dim (D) and CADM1⁺CD7⁻ (N) subpopulations are observed. The D and N subpopulations increase as asymptomatic HTLV-1 carriers (AC) progress to indolent adult T-cell leukemia-lymphoma (ATL) and the N subpopulation then expands in aggressive ATL. In the present study we examined whether the analysis can estimate the risk of developing ATL in advanced AC. Peripheral blood samples from AC (N = 41) and indolent ATL patients (N = 19) were analyzed by flow cytometry using the CADM1 versus CD7 plot for CD4⁺ cells and inverse long PCR (clonality analysis) of FACS-sorted subpopulations. Almost all AC with a high HTLV-1 proviral load (>4 copies/100 cells) had a CADM1⁺ (D + N) frequency of >10%. AC with 25% < CADM1⁺ ≤ 50% contained expanded clones similar to smoldering-type ATL. In many patients in the 25% < CADM1⁺ ≤ 50% group, the proportion of abnormal lymphocytes was distributed around the 5% line, which divides AC and smoldering-type ATL in Shimoyama's classification. In conclusion, the CADM1 versus CD7 plot is useful for selection of putative high-risk AC. The characteristics of some AC and smoldering ATL are said to be similar; however, long-term follow up is required and the clinical outcome (e.g. rate of transformation) of these cases should be used to determine whether to include them in the same clinical category.

Aggressive adult T cell leukemia/lymphoma: the tip of the iceberg of the hidden human T cell lymphotropic virus type 1 infection burden in nonendemic countries

Adult T cell leukemia/lymphoma has only rarely been reported in Europe. We aimed to determine the clinical characteristics and outcome of adult T cell leukemia/lymphoma patients in a nonendemic country. Cases of adult T cell leukemia/lymphoma managed at Hospital Universitari Vall d'Hebron, Barcelona, Spain were reviewed. Information on the foreign population living in Spain, according to country of origin, was obtained using official published data from the National Statistics Institute. Three patients were diagnosed with adult T cell leukemia/lymphoma between 2003 and 2010. Two cases were of the acute subtype and one case of the lymphoma subtype. Two patients were female and the mean age at presentation was 41.3 years. Patients originated from three different countries. The characteristics of the attended patients include widespread enlargement of the lymph nodes, a variety of multiple extranodal involvements, bone marrow infiltration, and a high incidence of infections including latent parasitic infections. Prototypic adult T cell leukemia/lymphoma presenting with high white cell counts, flower cells, and hypercalcemia was not observed. Regarding therapy, one patient received chemotherapy alone and two subjects combined first-line therapy including antiviral drugs. Of the three patients, two are dead (mean survival time 6 months) and one has been lost to follow-up. We estimate that at least 15,000 people living in Spain are infected with human T cell lymphotropic virus type 1 (HTLV-1). Adult T cell leukemia/lymphoma is a heterogeneous disease that often presents without distinguishing or prototypical features. A high index of clinical suspicion is essential for diagnosis. Several epidemiological differences have been observed in different countries. Today, HTLV-1 infection is highly underdiagnosed.

Pre-morbid human T-lymphotropic virus type I proviral load, rather than percentage of abnormal lymphocytes, is associated with an increased risk of aggressive adult T-cell leukemia/lymphoma

Out of 153 newly referred human T-lymphotropic virus type I infected patients, 42 (27%) had 5% or more abnormal lymphocytes, consistent with the diagnosis of smoldering adult T-cell leukemia/lymphoma. The abnormal lymphocyte percentage was higher in patients with human T-lymphotropic virus type I associated inflammatory disease compared with asymptomatic carriers (P=0.006). Over 4.5 years median follow up, 4 patients, all with 10 or more human T-lymphotropic virus type I DNA copies/100 peripheral blood mononuclear cells at presentation, but only one with 5% or more abnormal lymphocytes at presentation, developed adult T-cell leukemia/lymphoma. Thus, high pre-morbid human T-lymphotropic virus type I proviral load, rather than fulfilment of the classification criteria for smoldering adult T-cell leukemia/lymphoma, was associated with an increased risk of developing aggressive adult T-cell leukemia/lymphoma.

Leukemic T cells are specifically enriched in a unique CD3(dim) CD7(low) subpopulation of CD4(+) T cells in acute-type adult T-cell leukemia

The morphological discrimination of leukemic from non-leukemic T cells is often difficult in adult T-cell leukemia (ATL) as ATL cells show morphological diversity, with the exception of typical "flower cells." Because defects in the expression of CD3 as well as CD7 are common in ATL cells, we applied multi-color flow cytometry to detect a putative leukemia-specific cell population in the peripheral blood from ATL patients. CD4(+) CD14(-) cells subjected to two-color analysis based on a CD3 vs CD7 plot clearly demonstrated the presence of a CD3(dim) CD7(low) subpopulation in each of nine patients with acute-type ATL. The majority of sorted cells from this fraction showed a flower cell-like morphology and carried a high proviral load for the human T-cell leukemia virus type 1 (HTLV-I). Genomic integration site analysis (inverse long-range PCR) and analysis of the T cell receptor Vβ repertoire by flow cytometry indicated that the majority of leukemia cells were included in the CD3(dim) CD7(low) subpopulation. These results suggest that leukemic T cells are specifically enriched in a unique CD3(dim) CD7(low) subpopulation of CD4(+) T cells in acute-type ATL.

Flower cells in patients with infective dermatitis associated with HTLV-1

BACKGROUND

Infective dermatitis associated with HTLV-1 (IDH) is a severe childhood form of eczema that may progress to adult T-cell leukemia/lymphoma (ATL).

OBJECTIVE

In this study, the presence of clinical and laboratory parameters suggestive of ATL was evaluated in a cohort of 30 patients with IDH.

STUDY DESIGN

Over a period of 33 months, the patients were submitted to three-monthly clinical evaluations, routine laboratory exams, full blood count and blood smears, and to six-monthly blood sampling for HTLV-1 proviral load determination. HTLV-1 proviral load was quantified using real-time TaqMan PCR assay.

RESULTS

Abnormal cells (Ably) were found in the peripheral blood smears of nine patients (30%), flower cells being detected in five of these cases (16.6%). The presence of Ably and flower cells was not associated with a higher proviral load in those patients.

CONCLUSIONS

This is the first report on the presence of flower cells in HTLV-1-infected children and adolescents. Furthermore, these cells have not previously been reported in IDH patients. The cases with flower cells probably represent precursory ATL cases, these patients being at a greater risk of developing ATL.

Adult T-Cell Leukemia/Lymphoma with CLL-Like Morphology-A Case Report

Adult T-cell Leukemia/Lymphoma (ATL) is rarely seen in the U.S. and Europe, usually limited to African Americans from the southeastern U.S. and immigrants from HTLV-1 endemic areas. Reaching an accurate and timely diagnosis of ATL in such nonendemic areas can be challenging, owing to limited exposure, diverse manifestations, and varying cell morphology. We present a case of chronic adult T-cell leukemia (ATL) with Chronic Lymphocytic Leukemia- (CLL-) like morphology that remained untreated for ten years and then developed treatment refractory acute ATL crisis.

Definition, prognostic factors, treatment, and response criteria of adult T-cell leukemia-lymphoma: a proposal from an international consensus meeting

Adult T-cell leukemia-lymphoma (ATL) is a distinct peripheral T-lymphocytic malignancy associated with a retrovirus designated human T-cell lymphotropic virus type I (HTLV-1). The diversity in clinical features and prognosis of patients with this disease has led to its subclassification into the following four categories: acute, lymphoma, chronic, and smoldering types. The chronic and smoldering subtypes are considered indolent and are usually managed with watchful waiting until disease progression, analogous to the management of some patients with chronic lymphoid leukemia (CLL) or other indolent histology lymphomas. Patients with aggressive ATL generally have a poor prognosis because of multidrug resistance of malignant cells, a large tumor burden with multiorgan failure, hypercalcemia, and/or frequent infectious complications as a result of a profound T-cell immunodeficiency. Under the sponsorship of the 13th International Conference on Human Retrovirology: HTLV, a group of ATL researchers joined to form a consensus statement based on established data to define prognostic factors, clinical subclassifications, and treatment strategies. A set of response criteria specific for ATL reflecting a combination of those for lymphoma and CLL was proposed. Clinical subclassification is useful but is limited because of the diverse prognosis among each subtype. Molecular abnormalities within the host genome, such as tumor suppressor genes, may account for these diversities. A treatment strategy based on the clinical subclassification and prognostic factors is suggested, including watchful waiting approach, chemotherapy, antiviral therapy, allogeneic hematopoietic stem-cell transplantation (alloHSCT), and targeted therapies.

Current Status of Therapeutic Approaches to Adult T-Cell Leukemia

More than 2 decades have elapsed since the proposal of adult T-cell leukemia (ATL). Since then, the discovery of the etiologic virus, human T-cell leukemia virus type I (HTLV-I), and the establishment of the diagnostic steps of serum test and molecular study have clearly defined ATL as a distinct disease entity. Because conventional chemotherapy, which is active against other lymphoid malignancies, was proven to be ineffective for treating aggressive forms of ATL, ATL has become the target of several clinical studies for the purpose of improving therapeutic outcomes. Combination chemotherapy exclusively designed for ATL has considerably elevated the treatment response rate in ATL patients, but it has not sufficiently extended the median survival time. The introduction of antiviral agents has led to surprising effects for patients with acute ATL. Monoclonal antibodies seem to be promising, especially for patients with chemotherapy-resistant disease. Unfortunately, these approaches did not prove to be sufficient for most patients with ATL to obtain long-term survival. Recent promising reports on allogeneic stem cell transplantation (allo-SCT) for ATL have suggested that allo-SCT could overcome the limitations that other treatment modalities have not surmounted. More efforts are clearly needed to clarify the usefulness of allo-SCT, especially with reduced-intensity conditioning regimens, for ATL patients.

Update in the pathologic features of mature B-cell and T/NK-cell leukemias

Modern diagnosis of mature B- and T-cell leukemias requires integration of morphologic, immunophenotypic, and molecular genetic features. This integrative approach has allowed more precise definitions of specific disease entities. This in turn provides better information for clinicians to select proper therapy and determine prognosis. The characteristic pathologic features of these disorders are reviewed.

Mutations in the mitotic check point gene, MAD1L1, in human cancers

Aneuploidy is a characteristic of the majority of human cancers, and recent studies suggest that defects of mitotic checkpoints play a role in carcinogenesis. MAD1L1 is a checkpoint gene, and its dysfunction is associated with chromosomal instability. Rare mutations of this gene have been reported in colon and lung cancers. We examined a total of 44 cell lines (hematopoietic, prostate, osteosarcoma, breast, glioblastoma and lung) and 133 fresh cancer cells (hematopoietic, prostate, breast and glioblastoma) for alterations of MAD1L1 by RT-PCR-SSCP and nucleotide sequencing. Eight mutations consisting of missense, nonsense and frameshift mutations were found, together with a number of nucleotide polymorphisms. All the alterations in cell lines were heterozygous. Frequency of mutations was relatively high in prostate cancer (2/7 cell lines and 2/33 tumor specimens). We placed a mutant truncated MAD1L1, found in a lymphoma sample, into HOS, Ht161 and SJSA cell lines and found that it was less inhibitory than wild type MAD1L1 at decreasing cell proliferation. Co-expression experiments showed that the mutant form had a dominant-negative effect. Furthermore, this mutant impaired the mitotic checkpoint as shown by decreased mitotic indices in HOS cells expressing mutant MAD1L1 after culture with the microtubule-disrupting agent, nocodazole. Our results suggest a pathogenic role of MAD1L1 mutations in various types of human cancer.

Human T-lymphotropic virus type 1 infection

Human T-cell lymphotropic virus type-1 (HTLV-1) is aetiologically associated with adult T-cell leukaemia/lymphoma (ATL). HTLV-1 infection can also lead to various non-malignant diseases, for example, HTLV-1 associated myelopathy/tropical spastic paraparesis and HTLV-1 uveitis. HTLV-1 is endemic in southern Japan and the Caribbean. HTLV-1 infection is mainly transmitted by either breast-feeding, sexual intercourse or blood transfusions. Primary prevention of HTLV-1 in endemic areas by screening of blood and by refraining from breast-feeding have been successful. The incidence of ATL is rather low among HTLV-1 carriers (<5%). The precise mechanism of development of ATL remains unknown. It is a multiple-step process which does not require viral expression in the later stages of leukaemogenesis. Many samples have mutations of the tumour suppressor genes, p53 and/or p16(INK4A). Four subtypes of ATL have been identified, each having distinctive clinical features. Monoclonal integration of HTLV-1 proviral DNA into tumour cells is found in each of the subtypes. At present, no effective therapy for ATL exists.