Origin and prevalence of human T-lymphotropic virus type 1 (HTLV-1) and type 2 (HTLV-2) among indigenous populations in the Americas

Angioimmunoblastic T-cell lymphoma: the many-faced lymphoma

Angioimmunoblastic T-cell lymphoma (AITL) is an uncommon subtype of mature peripheral T-cell lymphoma (PTCL). The history of AITL is much longer and deeper than the literature would suggest given the many names that have preceded it. Advanced-stage disease is common with uncharacteristic laboratory and autoimmune findings that often slow or mask the diagnosis. Significant strides in the immunohistochemical and molecular signature of AITL have brought increased ability to diagnose this uncommon type of PTCL. The 2016 World Health Organization classification of lymphoid neoplasms recently acknowledged the complexity of this diagnosis with the addition of other AITL-like subsets. AITL now resides under the umbrella of nodal T-cell lymphomas with follicular T helper phenotype. Induction strategies continue to focus on increasing complete remission rates that allow more transplant-eligible patients to proceed toward consolidative high-dose therapy and autologous stem cell rescue with improving long-term survival. There are several clinical trials in which recently approved drugs with known activity in AITL are paired with induction regimens with the hope of demonstrating long-term progression-free survival over cyclophosphamide, doxorubicin, vincristine, and prednisone. The treatment of relapsed or refractory AITL remains an unmet need. The spectrum of AITL from diagnosis to treatment is reviewed subsequently in a fashion that may one day lead to personalized treatment approaches in a many-faced disease.

Evaluation of human T-lymphotropic virus prevalence/co-infection rates for a four-year period in a non-metropolitan blood center in Southeast Brazil

INTRODUCTION

Human T-lymphotropic virus types 1/2 (HTLV-1/2) are distributed worldwide and are endemic in specific regions.

METHODS

Serological evaluation of the HTLV-1/2 prevalence and co-infection rate [human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), Chagas disease, and syphilis)] for 2011-2014 was performed with volunteer blood donors from the western part of São Paulo State.

RESULTS

Serrana and Araçatuba had higher HTLV seroprevalence rates (0.1%); while Franca, Olimpia, and Bebedouro had lower seroprevalences (0.04%). Co-infection (HBV and syphilis) was present in 12.3% of HTLV-infected blood donors.

CONCLUSIONS

Our findings provide data for the prevalence of HTLV in Brazil and demonstrate the importance of regional and global hemovigilance.

SEROPREVALENCE OF HTLV IN A POPULATION OF HIV1-INFECTED PATIENTS IN MIDWESTERN BRAZIL

Human T-cell lymphotropic virus (HTLV) may affect the clinical course of human immunodeficiency virus 1 (HIV1). Both infections are common in endemic areas because these viruses share similar routes of transmission. The aim of this study was to estimate the seroprevalence of HTLV1/2 in a population of HIV1-infected patients in the state of Goiás, Midwestern Brazil. Of the 505 studied patients, four (0.79%) were positive for anti-HTLV1/2 by enzyme-linked immunosorbent assay (ELISA), with HTLV1 infection confirmed by line immunoassay (LIA) and polymerase chain reaction (PCR) in all of the ELISA-positive samples. No cases of HTLV2 infection were observed. The prevalence of HTLV1/HIV1 coinfection was 0.79% (4/505; 95% CI: 0.25-2.16). All the coinfected patients reported sexual risk behaviors and only one reported intravenous drug use. Sequencing of the viral long terminal repeat (LTR) region and phylogenetic analysis revealed that the four HTLV1 isolates belonged to the Transcontinental a subgroup of the Cosmopolitan (1a) subtype, the most frequent subgroup detected in Brazil. This study shows a low prevalence of HTLV1/2 in HIV1-infected patients in Midwestern Brazil.

Spotting the enemy within: Targeted silencing of foreign DNA in mammalian genomes by the Krüppel-associated box zinc finger protein family

Tandem C2H2-type zinc finger proteins (ZFPs) constitute the largest transcription factor family in animals. Tandem-ZFPs bind DNA in a sequence-specific manner through arrays of multiple zinc finger domains that allow high flexibility and specificity in target recognition. In tetrapods, a large proportion of tandem-ZFPs contain Krüppel-associated-box (KRAB) repression domains, which are able to induce epigenetic silencing through the KAP1 corepressor. The KRAB-ZFP family continuously amplified in tetrapods through segmental gene duplications, often accompanied by deletions, duplications, and mutations of the zinc finger domains. As a result, tetrapod genomes contain unique sets of KRAB-ZFP genes, consisting of ancient and recently evolved family members. Although several hundred human and mouse KRAB-ZFPs have been identified or predicted, the biological functions of most KRAB-ZFP family members have gone unexplored. Furthermore, the evolutionary forces driving the extraordinary KRAB-ZFP expansion and diversification have remained mysterious for decades. In this review, we highlight recent studies that associate KRAB-ZFPs with the repression of parasitic DNA elements in the mammalian germ line and discuss the hypothesis that the KRAB-ZFP family primarily evolved as an adaptive genomic surveillance system against foreign DNA. Finally, we comment on the computational, genetic, and biochemical challenges of studying KRAB-ZFPs and attempt to predict how these challenges may be soon overcome.