SARS-CoV-2 Infection During Induction Chemotherapy in a Child With High-risk T-Cell Acute Lymphoblastic Leukemia.

The clinical course of SARS-CoV-2 infection (COVID-19) in children with hematologic malignancies is unclear. We describe the diagnosis, treatment and outcome of a 4-year-old boy with high-risk acute lymphoblastic leukemia and COVID-19. Regardless of immunosuppressive induction chemotherapy his symptoms remained moderate. He received only supportive treatment. Seroconversion occurred in a similar period as in immunocompetent adults. Despite prolonged myelosuppression he did neither acquire secondary infections nor did the treatment delay caused by the infection have a measurable negative impact on the residual disease of acute lymphoblastic leukemia. Intriguingly, residual leukemia even decreased even though he did not receive any antileukemic therapy.

Unusual lymphoid malignancy and treatment response in two children with Down syndrome.

BACKGROUND: Lymphoid malignancies other than acute lymphoblastic leukemia (ALL) are rare in children with Down syndrome (DS). Information about the toxicity of chemotherapy and prognosis is largely derived from the experience of children with DS and ALL or children without DS. PROCEDURE: We describe the treatment and outcome of two unusual lymphoid malignancies in children with DS. One patient was diagnosed with Burkitt lymphoma (BL) and the second, after treatment for B precursor ALL, with T-cell EBV-positive proliferative disorder (LPD). RESULTS: BL was treated with standard doses of LMB group B therapy subsequently intensified to group C therapy, including high-dose methotrexate (HD-MTX, 3-8 g/m2 ). The patient did not experience excessive toxicity and remains in complete remission 13 months later. Despite presentation with disseminated disease the patient with T-cell EBV-positive LPD after treatment for B precursor ALL responded to dexamethasone and rituximab and remains in complete remission two years later. CONCLUSIONS: Upfront reduction of the high treatment intensity, which is associated with excellent survival outcomes in BL, may not be warranted in all children with DS. Response to therapy and prognosis of T-cell EBV-positive LPD in a patient with DS was not predicted by reported experience in the absence of DS.

BCL11B is frequently downregulated in HTLV-1-infected T-cells through Tax-mediated proteasomal degradation.

Human T-cell leukemia virus type 1 (HTLV-1) is a causative agent of adult T-cell leukemia-lymphoma (ATLL). The HTLV-1-encoded protein Tax plays important roles in the proliferation of HTLV-1-infected T-cells by affecting cellular proteins. In this study, we showed that Tax transcriptionally and post-transcriptionally downregulates the expression of the tumor suppressor gene B-cell leukemia/lymphoma 11B (BCL11B), which encodes a lymphoid-related transcription factor. BCL11B expression was downregulated in HTLV-1-infected T-cell lines at the mRNA and protein levels, and forced expression of BCL11B suppressed the proliferation of these cells. The proteasomal inhibitor MG132 increased BCL11B expression in HTLV-1-infected cell lines, and colocalization of Tax with BCL11B was detected in the cytoplasm of HTLV-1-infected T-cells following MG132 treatment. shRNA knock-down of Tax expression also increased the expression of BCL11B in HTLV-1-infected cells. Moreover, we found that Tax physically binds to BCL11B protein and induces the polyubiquitination of BCL11B and proteasome-dependent degradation of BCL11B. Thus, inactivation of BCL11B by Tax protein may play an important role in the Tax-mediated leukemogenesis.

Epstein-Barr Virus-associated Mucocutaneous Ulcer in a Patient With T-Cell Acute Lymphoblastic Leukemia: Importance of Accurate Diagnosis and Conservative Management.

Epstein-Barr virus-associated mucocutaneous ulcer (EBV-MCU) is a recently characterized entity that falls under the spectrum of EBV-lymphoproliferative disorders. First described in 2010 by Dojcinov et al, it is an EBV-driven localized proliferation of B cells, occurring in mucocutaneous tissues including the skin, the oropharynx, and the gastrointestinal tract of immunosuppressed patients in the absence of an intact T-cell repertoire. Typically, it has been described in elderly patients with age-related immunosenescence and patients who are on immunosuppressive therapy. However, only 2 cases have been reported in pediatric, adolescent, and young adult age groups, with all these patients manifesting after solid organ transplant. To the best of our knowledge there are no case reports of EBV-MCU occurring in association with hematologic malignancy. Here, we present a case of EBV-MCU in a young adult patient with T-cell acute lymphoblastic leukemia. Our report serves to promote awareness among clinicians regarding this newly described and extremely rare clinical entity in young immunosuppressed patients. In addition, we highlight the importance of accurate diagnosis to prevent overtreatment of this indolent, often self-resolving disease that has a significant clinicopathologic overlap with other aggressive forms of EBV-lymphoproliferative disorders that require more intensive therapy.

Impaired expression of DICER and some microRNAs in HBZ expressing cells from acute adult T-cell leukemia patients.

Global dysregulation of microRNAs (miRNAs), a class of non-coding RNAs that regulate genes expression, is a common feature of human tumors. Profiling of cellular miRNAs on Adult T cell Leukemia (ATL) cells by Yamagishi et al. showed a strong decrease in expression for 96.7% of cellular miRNAs in ATL cells. However, the mechanisms that regulate the expression of miRNAs in ATL cells are still largely unknown. In this study, we compared the expression of 12 miRs previously described for being overexpress by Tax and the expression of several key components of the miRNAs biogenesis pathways in different HBZ expressing cell lines as well as in primary CD4 (+) cells from acute ATL patients. We showed that the expression of miRNAs and Dicer1 were downregulated in cells lines expressing HBZ as well as in fresh CD4 (+) cells from acute ATL patients. Using qRT-PCR, western blotting analysis and Chromatin Immunoprecipitation, we showed that dicer transcription was regulated by c-Jun and JunD, two AP-1 transcription factors. We also demonstrated that HBZ affects the expression of Dicer by removing JunD from the proximal promoter. Furthermore, we showed that at therapeutic concentration of 1mM, Valproate (VPA) an HDAC inhibitors often used in cancer treatment, rescue Dicer expression and miRNAs maturation. These results might offer a rationale for clinical studies of new combined therapy in an effort to improve the outcome of patients with acute ATL.

Adult T-cell leukemia/lymphoma with an unusual CD1a positive phenotype.

BACKGROUND: Acute T-cell leukemia lymphoma (ATLL) tumor cells generally express CD2/CD3/CD5, but lack CD7. These T cells are usually CD4+CD8- and strongly express CD25, although some variability in this basic pattern may be found. Here we report a case with a very unusual CD1a positive phenotype. METHODS: Samples from peripheral blood, bone marrow aspirate, lymph node, and cerebrospinal fluid obtained from a 45-year-old male patient with a T-cell lymphoproliferative disorder were immunophenotyped by multiparametric flow cytometry. Analysis of HTLV-I genome integration in tumoral cells was performed by PCR. RESULTS: Neoplastic T cells were cCD3, CD2/CD5/CD30/CD25, and CD1a positive, but CD3/CD7/CD4/CD8/CD34/CD10/TdT negative. Serology and integration of HTLV-I were positive. CONCLUSION: To the best of our knowledge, CD1a expression has not been previously described in this entity. Its detection raised the differential diagnosis with acute T lymphoblastic leukemia. The rest of the phenotypic markers, the morphology of the neoplastic cells, and the demonstration of HTLV-I genome integration provided the final diagnosis.

[Human T-cell lymphotropic virus type I infection in patients with lymphoproliferative disorders at two sentinel sites in Cuba]. / Infección por el HTLV-I en pacientes con síndromes linfoproliferativos en dos sitios centinela de Cuba.

OBJECTIVE: To determine the prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection among patients with lymphoproliferative disorders, as well as among their family members and sexual contacts, at two sentinel sites in Cuba. METHODS: An analysis was conducted of all the patients with a presumptive diagnosis of hematological malignancies seen by the hematology departments of the Hospital Hermanos Ameijeiras (HHA), City of Havana, and the Hospital Provincial Comandante Faustino Pérez (HPCFP), Matanza, Cuba, in January 1996-January 1997. HTLV-I seropositivity was determined by ELISA and Western Blot, and infection was confirmed by polymerase chain reaction. The positive patients' family members and sexual contacts were also assessed. The Z-test was used to compare proportions. RESULTS: Seroprevalence of HTLV-I infection in patients with lymphoproliferative disorders was 0.4% higher at the HPCFP than at the HHA (6.1% versus 0.2%, P<0.001). There were no significant differences in prevalence by age, sex, or skin color. Of the 53 family members and sexual contacts studied, 8 (15.1%) were positive for HTLV-I infection. CONCLUSION: The prevalence of HTLV-I in the study group was higher than previously found in Cuba. The value of seroepidemiological surveillance through sentinel sites was confirmed.

Infección por el HTLV-I en pacientes con síndromes linfoproliferativos en dos sitios centinela de Cuba / Human T-cell lymphotropic virus type I infection in patients with lymphoproliferative disorders at two sentinel sites in Cuba

OBJETIVO: Determinar la frecuencia de la infección por el HTLV-I en pacientes con síndromes linfoproliferativos, así como en sus familiares y contactos sexuales, en dos sitios de vigilancia centinela en Cuba. MÉTODOS: Se analizaron todos los pacientes que tenían un diagnóstico presuntivo de neoplasias hematológicas entre enero de 1996 y enero de 2007 atendidos en los servicios de hematología del Hospital Hermanos Ameijeiras (HHA), de Ciudad de La Habana, y el Hospital Provincial Comandante Faustino Pérez (HPCFP), de Matanzas, Cuba. Se determinó la seropositividad al HTLV-I por ELISA y western blot y se confirmó la infección mediante la reacción en cadena de la polimerasa. Se estudiaron también los familiares y los contactos sexuales de los pacientes positivos. Se utilizó la prueba de la Z para la comparación de proporciones. RESULTADOS: La seroprevalencia de la infección por el HTLV-I en pacientes con síndromes linfoproliferativos fue de 0,4 por ciento, mayor en el HPCFP que en el HHA (6,1 por ciento frente a 0,2 por ciento; P < 0,001). No se encontraron diferencias significativas en la frecuencia de la infección según la edad, el sexo y el color de la piel. De los 53 familiares y contactos sexuales estudiados, 8 (15,1 por ciento) tuvieron diagnóstico positivo de infección por el HTLV-I. CONCLUSIÓN: La frecuencia de la infección por el HTLV-I en el grupo estudiado fue superior a la encontrada con anterioridad en Cuba. Se confirmó la utilidad de la vigilancia seroepidemiológica mediante centros centinela.

OBJECTIVE: To determine the prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection among patients with lymphoproliferative disorders, as well as among their family members and sexual contacts, at two sentinel sites in Cuba. METHODS: An analysis was conducted of all the patients with a presumptive diagnosis of hematological malignancies seen by the hematology departments of the Hospital Hermanos Ameijeiras (HHA), City of Havana, and the Hospital Provincial Comandante Faustino Pérez (HPCFP), Matanza, Cuba, in January 1996-January 1997. HTLV-I seropositivity was determined by ELISA and Western Blot, and infection was confirmed by polymerase chain reaction. The positive patients' family members and sexual contacts were also assessed. The Z-test was used to compare proportions. RESULTS: Seroprevalence of HTLV-I infection in patients with lymphoproliferative disorders was 0.4 percent higher at the HPCFP than at the HHA (6.1 percent versus 0.2 percent, P < 0.001). There were no significant differences in prevalence by age, sex, or skin color. Of the 53 family members and sexual contacts studied, 8 (15.1 percent) were positive for HTLV-I infection. CONCLUSION: The prevalence of HTLV-I in the study group was higher than previously found in Cuba. The value of seroepidemiological surveillance through sentinel sites was confirmed.

Prevalence of HHV-6 integrated chromosomally among children treated for acute lymphoblastic or myeloid leukemia in the Czech Republic.

Chromosomal integration of human herpesvirus 6 (HHV-6) is a novel situation found in a small percentage of individuals. While active HHV-6 infection is treatable using antivirals, the abnormally high level of HHV-6 DNA found in chromosomal integration of HHV-6 (CI-HHV-6) is not affected by such drugs. Stored DNA samples taken originally for detection of fusion genes and minimal residual disease from 339 pediatric patients treated for leukemia in the Czech Republic between the years 1995-2007 were tested retrospectively. Using real-time quantitative PCR technology, the quantity of HHV-6 DNA detected was normalized to 100,000 human genome equivalents as assessed by quantitation of the albumin gene. HHV-6 DNA was detected in 107 samples from 91 patients (26.8%). In the majority of samples (99) only a minute level of normalized viral copies (NVCs) (median 1.84 NVCs) was detected. A high viral load of approximately 100,000 NVCs was detected in 5 patients (1.5%; median 140,150 NVCs), in all of whom were confirmed subsequently CI-HHV-6 by a detection of HHV-6 DNA in hair follicles or in the nails. In all but one patient with HHV-6 variant B, variant A of the virus was detected. None of the patients with CI-HHV-6 had complications attributable to HHV-6 infection. The prevalence of CI-HHV-6 in childhood leukemia does not differ from that published for other patients or healthy populations. Where high levels of HHV-6 DNA are present, CI-HHV-6 should be confirmed as soon as possible so that potentially toxic but ineffective antiviral treatment can be stopped.

Quantitation of Human herpes virus 6 genome in children with acute lymphoblastic leukemia.

Acute lymphoblastic leukemia is the main type of leukemia in children. An infectious etiology has been suspected and the role of the Human herpesvirus-6 (HHV-6) has been suggested. Several studies have tried to establish a link between HHV-6 infections and hematological malignancies, with discordant results. The potential role of HHV-6 in the pathogenesis of pediatric acute lymphoblastic leukemia was investigated. HHV-6 genome copy number was measured by quantitative real-time PCR (RQ-PCR) in bone marrow or peripheral blood samples obtained from 36 children (median age = 4 years) with B acute lymphoblastic leukemia (n = 31) and T acute lymphoblastic leukemia (n = 5) at diagnosis and during complete remission. Positive samples were further characterized to define viral variant, A or B. A total of 24.7% of samples were positive for HHV-6 genome: 13.9% were leukemia samples and 34.1% were complete remission samples. Viral load was low with values lower at diagnosis (median viral copy number = 22.9) than at complete remission (median copy number = 60.1). Among the 17 patients with positive samples, 15 were typed as B-variant whereas 2 could not be typed. These results argue against a role of HHV6 infection in the development of pediatric acute lymphoblastic leukemia. They also suggest that HHV-6 may infect latently bone marrow progenitors but seems not able to infect leukemic cells, raising again the question of the mechanism of virus fusion and entry. This observation shows that a reactivation may be observed during complete remission supporting the possibility of virus reactivation in immunocompromised hosts.

No genetic evidence for involvement of Deltaretroviruses in adult patients with precursor and mature T-cell neoplasms.

BACKGROUND: The Deltaretrovirus genus comprises viruses that infect humans (HTLV), various simian species (STLV) and cattle (BLV). HTLV-I is the main causative agent in adult T-cell leukemia in endemic areas and some of the simian T-cell lymphotropic viruses have been implicated in the induction of malignant lymphomas in their hosts. BLV causes enzootic bovine leukosis in infected cattle or sheep. During the past few years several new Deltaretrovirus isolates have been described in various primate species. Two new HTLV-like viruses in humans have recently been identified and provisionally termed HTLV-III and HTLV-IV. In order to identify a broad spectrum of Deltaretroviruses by a single PCR approach we have established a novel consensus PCR based on nucleotide sequence data obtained from 42 complete virus isolates (HTLV-I/-II, STLV-I/-II/-III, BLV). The primer sequences were based on highly interspecies-conserved virus genome regions. We used this PCR to detect Deltaretroviruses in samples from adult patients with a variety of rare T-cell neoplasms in Germany. RESULTS: The sensitivity of the consensus PCR was at least between 10-2 and 10-3 with 100% specificity as demonstrated by serial dilutions of cell lines infected with either HTLV-I, HTLV-II or BLV. Fifty acute T-cell lymphoblastic leukemia (T-ALL) samples and 33 samples from patients with various rare mature T-cell neoplasms (T-PLL, Sézary syndrome and other T-NHL) were subsequently investigated. There were no cases with HTLV-I, HTLV-II or any other Deltaretroviruses. CONCLUSION: The results rule out a significant involvement of HTLV-I or HTLV-II in these disease entities and show that other related Deltaretroviruses are not likely to be involved. The newly established Deltaretrovirus PCR may be a useful tool for identifying new Deltaretroviruses.