Takuya Fukushima

Background: Critically ill patients often have long-lasting limitations in activities of daily living, particularly in walking ability. Although early mobilization increases the likelihood of independent ambulation at hospital discharge, the timing at which different mobilization levels become associated with ambulatory recovery is unclear. This study describes the timing for achieving several mobilization levels and its associations with ambulatory recovery at hospital discharge.Methods: In this single-center retrospective cohort study, patients were divided into a regained group, composed of patients whose ambulation recovered to pre–intensive care unit (ICU) admission levels by hospital discharge, and a non-regained group. Multivariable logistic regression analyses and receiver operating characteristic curve analyses were performed to examine the association between the timing of mobilization (standing, marching in place, and assisted walking) and regained ambulation at hospital discharge.Results: In total, 295 patients were included, and 223 (76%) of them had regained ambulation at hospital discharge. The adjusted odds ratio for standing peaked on day 10 after ICU admission (odds ratio, 5.61; 95% CI, 2.21–17.76) and declined thereafter. The optimal cutoff time linking marching in place and walking with assistance to regained ambulation was also day 10 after ICU admission (marching in place: area under the curve [AUC], 0.78; sensitivity, 0.83; specificity, 0.64; and walking with assistance: AUC, 0.79; sensitivity, 0.77; specificity, 0.68).Conclusions: The findings suggest that mobility status on day 10 after ICU admission can serve as a pragmatic marker for identifying patients at risk of poor ambulatory recovery.

Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1) infection. Although most T-cell neoplasms that develop in HTLV-1 carriers are considered ATLL, non-ATLL T-cell lymphomas (TCLs) could also occur, as documented in only a few case reports. Herein, we presented 14 cases of non-ATLL TCLs arising in HTLV-1 carriers. All TCL cases were serologically positive for HTLV-1 antibody; Southern blot analysis for the viral integration of HTLV-1, in situ hybridization for HTLV-1 basic leucine zipper factor (HBZ-ISH), quantitative real-time PCR for HTLV-1 proviral load (HTLV-1-qPCR), the entire HTLV-1 genome sequence, and target capture sequencing rigorously excluded the possibility of ATLL. Various histological subtypes, such as six nodal T follicular helper cell lymphomas, angioimmunoblastic type/not otherwise specified (nTFHL-AI/NOS), two monomorphic epitheliotropic intestinal T-cell lymphomas (MEITL), two peripheral T-cell lymphomas, NOS (PTCL, NOS), and two anaplastic large cell lymphomas (ALCL), ALK-negative, were included. Each case exhibited immunophenotypes and genetic profiles consistent with its respective histological subtype, but atypical for ATLL. Three nTFHL-AI cases exhibited co-mutations of RHOA p.G17V, TET2, and IDH2 p.R172, characteristic of nTFHL-AI but not of ATLL. Among the molecular analytic modalities included in this study, the combination of HBZ-ISH and HTLV-1-qPCR represented the results obtained from the other more expensive modalities, indicating that this combination is effective in daily practice. When T-cell neoplasms arise in HTLV-1 carriers and exhibit atypical clinical, phenotypical, or genetic features for ATLL, it is recommended to perform HBZ-ISH and HTLV-1-qPCR to distinguish non-ATLL TCLs.

This single-arm, phase 3 trial by the Japan Clinical Oncology Group evaluated the strategy of upfront allogeneic hematopoietic stem cell transplantation (allo-HSCT) after intensive chemotherapy for untreated aggressive adult T-cell leukemia-lymphoma (ATL). Patients ≤ 65 years old with aggressive ATL were eligible. The protocol-treatment was VCAP-AMP-VECP as induction-chemotherapy followed by allo-HSCT in first remission. Between 2010 and 2020, 110 patients were enrolled. Among all 92 transplantations, 41 under per-protocol (study transplantation) and 51 under off-protocol received allo-HSCT. The primary endpoint was met with 3-year OS of 44.0% (90% CI, 36.0–51.6 > 25.0). The median survival time of the study transplantation and all transplantation was 3.0 (95% CI, 1.5–5.8) and 2.5 years (95% CI, 1.4–4.8), respectively. Multivariable analysis with a time-dependent covariate for transplantation revealed that the hazard ratio for OS of study transplantation was 0.915 (95% CI, 0.554–1.512). In study transplantation, the rate of treatment-related death (TRD) in related and unrelated transplantation was 16.7% and 20.7%, respectively. Thirty-four deaths due to disease progression (PD) were observed. Upfront allo-HSCT can be recommended for aggressive ATL despite a relatively high rate of PD and TRD. However, the survival benefit of study transplantation remains unclear considering the immortal bias.

Since forkhead box P3 (FOXP3) is a hallmark of regulatory T (Treg) cells, the expansion of FOXP3⁺ adult T-cell leukemia/lymphoma (ATL) cells is believed to contribute to immune suppression and the pathogenesis of ATL. However, the mechanisms underlying the expansion of FOXP3⁺ ATL cells remain unclear. OX40, a co-stimulatory molecule, is expressed in ATL cells, and OX40 signaling has been shown to promote the differentiation and proliferation of Treg cells in mouse models. To investigate the mechanisms driving the expansion of FOXP3⁺ ATL cells, we examined the expression of OX40 and its ligand, OX40L. Our findings revealed that OX40 expression was elevated in patients with ATL and with a high frequency of FOXP3⁺ ATL cells. Flow cytometric analysis of peripheral blood mononuclear cells (PBMCs) from patients with acute ATL cultured for 18 h demonstrated that FOXP3⁻ and FOXP3⁺ cells predominantly expressed OX40L and OX40, respectively. Furthermore, small interfering RNA-mediated FOXP3 knockdown in HTLV-1-infected cell lines increased OX40L expression. These results suggest that interactions between FOXP3⁻ OX40L⁺ cells and FOXP3⁺ OX40⁺ cells may promote the proliferation of FOXP3⁺ ATL cells.

Adult T-cell leukemia/lymphoma (ATL) cells express TNF receptor type-2 (TNFR2) on their surface and shed its soluble form (sTNFR2). We previously reported that sTNFR2 levels were highly elevated in the plasma of patients with acute ATL. To investigate whether its quantitation would be helpful for the diagnosis or prediction of the onset of acute ATL, we examined the plasma levels of sTNFR2 in a large number of specimens obtained from a cohort of ATL patients and asymptomatic human T-cell leukemia virus type 1 (HTLV-1) carriers (ACs) and compared them to those of other candidate ATL biomarkers (sCD25, sOX40, and IL-10) by enzyme-linked immunosorbent assays (ELISA) and HTLV-1 proviral loads. We observed that sTNFR2 levels were significantly elevated in acute ATL patients compared to ACs and patients with other types of ATL (chronic, smoldering, and lymphoma). Importantly, sTNFR2 levels were significantly correlated with those of sCD25, sOX40, and IL-10, as well as proviral loads. Thus, the present study confirmed that an increase in plasma sTNFR2 levels is a biomarker for the diagnosis of acute ATL. Examination of plasma sTNFR2 alone or in combination with other ATL biomarkers may be helpful for the diagnosis of acute ATL.

Adult T-cell leukemia/lymphoma (ATL) is a human T-cell leukemia virus type 1 (HTLV-1)–associated T-cell malignancy with generally poor prognosis. Although only ∼5% of HTLV-1 carriers progress to ATL, early diagnosis is challenging because of the lack of ATL biomarkers. In this study, we analyzed blood plasma profiles of asymptomatic HTLV-1 carriers (ACs); untreated ATL patients, including acute, lymphoma, smoldering, and chronic types; and ATL patients in remission. Through SOMAscan, expression levels of 1305 plasma proteins were analyzed in 85 samples (AC, n = 40; ATL, n = 40; remission, n = 5). Using gene set enrichment analysis and gene ontology, overrepresented pathways in ATL vs AC included angiogenesis, inflammation by cytokines and chemokines, interleukin-6 (IL-6)/JAK/STAT3, and notch signaling. In selecting candidate biomarkers, we focused on soluble tumor necrosis factor receptor 2 (sTNFR2) because of its active role in enriched pathways, extreme significance (Welch’s t test P < .00001), high discrimination capacity (area under the curve >0.90), and novelty in ATL research. Quantification of sTNFR2 in 102 plasma samples (AC, n = 30; ATL, n = 68; remission, n = 4) using enzyme-linked immunosorbent assay showed remarkable elevations in acute ATL, at least 10 times those of AC samples, and return of sTNFR2 to AC state levels after achieving remission. Flow cytometry and immunostaining validated the expression of TNFR2 in ATL cells. No correlation between sIL-2 and sTNFR2 levels in acute ATL was found, suggesting the possibility of sTNFR2 as an independent biomarker. Our findings represent the first extensive blood-based proteomic analysis of ATL, suggesting the potential clinical utility of sTNFR2 in diagnosing acute ATL.

Approximately one-tenth of the 10 million individuals living with human T-cell leukemia virus type-1 (HTLV-1) worldwide live in Japan. Most of these infected individuals live in the southwest region of Japan, including Okinawa prefecture; however, currently no prophylactic vaccine against HTLV-1 infection is available. For preventing the HTLV-1 spread, we previously generated a humanized monoclonal antibody (hu-LAT-27) that mediates both neutralization and antibody-dependent cellular cytotoxicity (ADCC). The neutralization epitope of LAT-27 is a linear amino acid sequence from residue 191 to 196 (Leu-Pro-His-Ser-Asn-Leu) of the HTLV-1 envelope gp46 protein. Here, we found that the LAT-27 epitope is well conserved among HTLV-1 clinical isolates prevalent in Okinawa. The hu-LAT-27 treatment inhibited syncytium formation by these clinical HTLV-1 isolates. Although an amino acid substitution at residue 192 in the LAT-27 epitope from proline to serine was found in a few HTLV-1 isolates, hu-LAT-27 could still react with a synthetic peptide carrying this amino acid substitution. These findings demonstrate the wide spectrum of hu-LAT-27 reactivity, suggesting that hu-LAT-27 may be a candidate drug for prophylactic passive immunization against HTLV-1 infection.

Background: EOS plays an important role in maintaining the suppressive function of regulatory T cells (Tregs), and induces a regulated transformation of Tregs into T helper-like cells, which are capable of secreting proinflammatory cytokines in response to specific inflammatory signals. Meanwhile, significant reduction in Treg activity along with production of proinflammatory cytokines has been reported in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Methods: In this study, to examine whether there is an alteration in EOS expression in peripheral blood mononuclear cells (PBMCs) derived from HTLV-1-infected individuals especially HAM/TSP, we investigated the expression of HTLV-1 tax genotype, proviral load (PVL), and the mRNA expression of tax, HBZ and EOS in HTLV-1 infected individuals including adult T-cell leukemia/lymphoma (ATL), HAM/TSP, or asymptomatic carriers. The expression levels of EOS mRNA and protein in various HTLV-1-infected or uninfected human T-cell lines were also investigated. Results: EOS was highly expressed at the protein level in most HTLV-1 infected T-cell lines, and was augmented after the HTLV-1 regulatory factor Tax was induced in a Tax-inducible JPX-9 cell line. Immunoprecipitation experiments demonstrated a physical interaction between EOS and the viral regulatory protein Tax, but not HBZ. Meanwhile, there was a significant decrease in EOS mRNA levels in PBMCs of HTLV-1 infected individuals irrespective of their clinical statuses. We found an inverse correlation between EOS mRNA levels and HTLV-1 PVL in ATL patients, and positive correlations between both EOS mRNA load and PVL, and EOS and HBZ mRNA load in HAM/TSP patients, whereas this correlation was not observed in other clinical statuses. Conclusions: These findings suggest that both Tax and HBZ can alter the expression of EOS through undetermined mechanisms, and dysregulated expression of EOS in PBMCs of HTLV-1 infected individuals may contribute to the pathological progression of HTLV-1-associated diseases, such as ATL and HAM/TSP.

Introduction: Adult T cell leukemia-lymphoma (ATL) is clinically divided into aggressive (acute and lymphoma) and indolent (chronic and smoldering) subtypes. Recent studies revealed that ATL has a wide variety of gene alternations (Nat Genet. 2015; 47:1304, Nature. 2016; 534:402). Consistent with the notion that human leukocyte antigen (HLA) play a critical role for immune response, reduced expression of HLA has been shown to associate with poor prognosis in various types of malignancies (Oncogene. 2008; 27:5869). However, it is extremely difficult to assess the impact of somatic mutations of HLA genes in cancer cells because of its highly polymorphic nature. Taking advantage of computational tools using whole-exome sequencing data, somatic mutations of HLA class I genes were previously reported in about 3% of various types of cancers (Nat Biotechnol. 2015; 33:1152). To date, HLA typing has been performed through partial sequencing data of polymorphic exons, resulting in the loss of critical information on the entire region of HLA genes. In this context, using a next generation sequence (NGS)-based HLA DNA typing method, we analyzed the entire region of HLA genes in ATL cells and its impact on clinical outcomes. Methods: The present study was approved by the Investigational Review Board of University of the Ryukyus and Tokai University. Peripheral blood mononuclear cells collected from 25 ATL patients (Pts) (20 with acute type and 5 with chronic type) were analyzed. Cell adhesion molecular 1 (CADM1)-positive ATL cells and CADM1-negative non-ATL cells were separated by a magnetic-activated cell-sorting protocol, and genomic DNAs in each fraction were distinctively extracted. The PCR products of the eight HLA loci (HLA-A, -B, -C, -DRB1, -DQA1, -DQB1, -DPA1 and -DPB1) were obtained using the previously designed long ranged PCR primers (Tissue Antigens. 2012; 80:305) that cover the entire HLA gene sequences from the enhancer-promoter region to the 3'UTR region. The full-length level HLA genotypes were determined by mapping of sequence reads obtained by the Ion Torrent system to HLA allele reference sequences in the international ImMunoGeneTics project (IMGT)-HLA database. Somatic mutations and loss of heterozygosity (LOH) generated in ATL cells were identified by detail comparison of sequence data between the ATL and non-ATL cells. Survival curves were estimated using the Kaplan-Meier method and compared by the log-rank test. Results: We found a total of 20 somatic mutations in ATL cells among 9 Pts, including 15 single nucleotide variations (SNVs) and 5 insertions/deletions (indels) (Table 1). Of the 15 SNVs, 3 were nonsense mutations in exon 2/3 of HLA-A/B, 7 were nonsynonymous mutations in exon 1/4/5 of HLA-A/B/C, and 2 were mutations at splice sites in intron 2 of HLA-B/C. The mutations of splice sites in intron 2 and all the 5 indels caused frameshift generating premature stop codons. In contrast to the exons, there were only 3 mutations found in introns. Of 8 Pts harboring LOH, two Pts showed LOH in HLA-A gene, 4 Pts in HLA-A, -C, and -B genes, one Pt in HLA-DRB1, -DQA1, -DQB1, -DPA1 and -DPB1 genes, and one Pt in all the HLA-genes from HLA-A to HLA-DPB1. All the somatic mutations altering the structure of the HLA proteins (St-mt) and/or LOH were found in Pts with acute type ATL, while no St-mt or LOH were detected in Pts with chronic type ATL. Pts with St-mt/LOH (n = 9) significantly worsened in 3 years overall survival rate as compared to that in Pts without St-mt/LOH (n = 16) (11 % vs. 32 %, P = 0.016) (Fig. 1A). Among Pts with acute type ATL, Pts with St-mutations/LOH (n = 9) also showed a trend to worsen in the survival rate as compared to those in Pts without St-mutation /LOH (n = 11) (11 % vs. 30 %, P=0.064) (Fig. 1B). Conclusion: NGS-based HLA gene analyses at full-length level revealed that St-mt/LOH were frequently occurred predominantly in HLA class I loci in tumor cells from Pts with aggressive ATL. Importantly, St-mt/LOH in HLA genes were associated with aggressive phenotypes and poor prognosis, suggesting the possibility that ATL cells would develop immune escape mechanisms through a variety of acquired abnormalities in HLA gene. Since allogeneic stem cell transplantation is an essential therapeutic option for aggressive ATL, comprehensive knowledges on HLA gene abnormalities provide considerable advantage to optimize therapeutic modalities. Disclosures: Fukushima: Daiichi-Sankyo: Research Funding.