Secondary central nervous system involvement in patients with diffuse large B-cell lymphoma treated with rituximab combined CHOP therapy - a supplementary analysis of JCOG0601

Secondary central nervous system involvement (sCNSi) in diffuse large B-cell lymphoma (DLBCL) is fatal. However, its features in patients with sCNSi who are categorized as lower risk by international prognostic index (IPI) or CNS-IPI are not yet fully understood. In the present analysis, we evaluated DLBCL patients who developed sCNSi at their first progression and who participated in JCOG0601, most of whom were lower risk by IPI. Of 409 patients, 21 (5.1%) developed sCNSi during a median follow-up of 4.9 years. Five-year cumulative incidence of sCNSi were 5.1%; and 4.0%, 5.3%, and 11.5% at low, intermediate, and high risk of CNS-IPI, respectively. The most common locations of extranodal lesions at the time of registration in patients with sCNSi were the stomach (n = 4), paranasal cavity (n = 3), and bone marrow (n = 2). In univariable analysis, paranasal cavity lesion was a high-risk factor for sCNSi (subdistribution hazard ratio, 4.34 [95% confidence interval 1.28-14.73]). Median overall survival after sCNSi was 1.3 years, with a 2-year overall survival rate of 39.3%. The incidence of sCNSi in DLBCL patients at lower risk of CNS-IPI was low, as previously reported, but paranasal cavity lesion might indicate high risk for organ involvement. CLINICAL TRIAL REGISTRATION: JCOG0601 was registered in the UMIN Clinical Trials Registry (UMIN000000929, date of registration; December 04, 2007) and the Japan Registry of Clinical Trials (jRCTs031180139, date of registration; February 20, 2019).

HTLV-1 cell-free DNA in plasma as a potential biomarker in HTLV-1 carriers and adult T-cell leukemia-lymphoma

Viral cell-free DNA (cfDNA) in plasma has been widely evaluated for detecting cancer and monitoring disease in virus-associated tumors. We investigated whether the amount of cfDNA of human T-cell leukemia virus type 1 (HTLV-1) correlates with disease state in adult T-cell leukemia-lymphoma (ATL). HTLV-1 cfDNA in aggressive ATL was significantly higher than that in indolent ATL and asymptomatic carriers. Notably, patients with lymphoma type represented higher HTLV-1 cfDNA amount than chronic and smoldering subtypes, though they had no abnormal lymphocytes in the peripheral blood. HTLV-1 cfDNA can be a universal biomarker that reflects the expansion of ATL clones.

Type II Cryoglobulinemic Membranoproliferative Glomerulonephritis Caused by Mucosa-associated Lymphoid Tissue Lymphoma

A 67-year-old man complained of lower limb edema with a purpuric skin rash. Laboratory tests revealed proteinuria, elevated serum creatinine levels, and low serum albumin levels. The patient was also positive for cryoglobulin in serum, immunoglobulin (Ig) M gammopathy, hypocomplementemia, and rheumatoid factor. He was negative for anti-hepatitis C virus antibodies. A pathological analysis of the renal tissue revealed membranoproliferative glomerulonephritis, common histological features of cryoglobulinemic vasculitis (CV), and mucosa-associated lymphoid tissue lymphoma invasion. Although hematologic malignancy is a rare cause of type II CV, these clinical findings suggest that mucosa-associated lymphoid tissue lymphoma (MALT) lymphoma may have been the cause in the present case.

[HLA-haploidentical peripheral blood stem cell transplantation with post-transplantation cyclophosphamide for adult T-cell leukemia]

Recently, allogeneic peripheral blood stem cell transplantation from human leukocyte antigen (HLA)-haploidentical donors using post-transplantation cyclophosphamide (PTCY-haploPBSCT) has become available in clinical practice. However, the efficacy of PTCY in adult T-cell leukemia (ATL) is not fully established yet. In this study, we retrospectively examined data of seven patients who underwent PTCY-haploPBSCT. The overall survival rate at 100 days after transplantation was 85.7%, and the 1-year overall survival rate was 68.6%. The cumulative incidence of relapse at 1 year was 31.4%, whereas the 1-year nonrelapse mortality was 17.1%. The cumulative incidence of grade III-IV acute graft-versus-host disease (GVHD) on day 100 was 14.3%, and the incidence of chronic GVHD at 1 year was 33.3%. These results suggest that PTCY-haploPBSCT can be a viable option even in patients with ATL. Further accumulation of knowledge and improvement of transplantation outcomes are warranted in the future.

Reconstitution of NK cells expressing KIR3DL1 is associated with reduced NK cell activity and relapse of CML after allogeneic hematopoietic stem cell transplantation

Although the prognosis of chronic myeloid leukemia (CML) in blastic crisis remains poor, some patients achieve long-term remission after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This may be attributable to graft-versus-leukemia (GVL) effects by donor lymphocytes, but their regulating mechanisms are unclear. Antitumor natural killer (NK) cell immunity is assumed to be important in CML, and we have previously shown that allelic polymorphisms of killer immunoglobulin-like receptors (KIRs) and histocompatibility leukocyte antigens (HLAs) are associated with the response of CML to tyrosine kinase inhibitors. Here, we report a case of CML in blastic phase who received HLA-matched but KIR3DL1 allelic-mismatched allo-HSCT. After transplant, decreased BCR-ABL transcript levels and enhanced NK cell activity were transiently observed. However, reconstitution of KIR3DL1-expressing NK cells occurred, which was associated with diminished NK cell activity and increased BCR-ABL. This case indicates the potential significance of KIR3DL1 in NK cell-mediated GVL activity following allo-HSCT. To the best of our knowledge, this is the first report to analyze the association between sequential KIR3DL1 expression and activity of NK cells after allo-HSCT. Selecting donors with KIR3DL1-null alleles may maintain competent GVL effects and provide improved outcomes in allo-HSCT for CML.

Clinical impact of the CONUT score in patients with multiple myeloma

Novel anti-myeloma drugs have significantly improved the overall survival (OS) of patients with multiple myeloma (MM). However, not all MM patients treated with these drugs show survival benefits, and biologic and genetic prognostic factors are insufficient to predict the response to treatment. Decreasing treatment-related complications is important to improve the efficacy of treatment in patients with MM. The Controlling Nutritional Status (CONUT) score is a screening method for poor nutritional status, which is associated with poor prognosis in several cancers because it increases the rate of treatment-related complications. We retrospectively analyzed the OS of 64 patients with symptomatic MM and evaluated the correlation between the CONUT score and patient prognosis in MM. The median age at diagnosis was 66 years, and multivariate analysis showed that a high CONUT score (≥ 5; hazard ratio, 3.937; 95% confidence interval, 1.214-12.658; P = 0.022) was an independent prognostic risk factor. Subgroup analysis was performed according to patient age because the choice of treatment strategy, particularly autologous peripheral blood stem cell transplantation (auto-PBSCT), can vary depending on age in MM patients. Younger patients (< 65 years old) who received auto-PBSCT and had a lower CONUT score (0-3) showed a significantly better survival outcome than those with a higher CONUT score (≥ 4) (median OS, not reached vs. 64.1 months; P = 0.011). The CONUT score is simple to calculate and provides a useful prognostic indicator in patients with MM, especially transplant-eligible patients.

Identification of the BRAF V600E mutation in Japanese patients with hairy cell leukemia and related diseases using a quenching probe method

Hairy cell leukemia (HCL) is a rare B-cell lymphoid malignancy that is difficult to distinguish from other morphological variants. The frequency of HCL has not been determined accurately in Japan. Recent studies revealed that the BRAF V600E mutation is the causal genetic event in HCL. We assessed the BRAF mutation in Japanese patients with HCL and related diseases using the quenching probe (QP) method, a single-nucleotide polymorphism detection system, and evaluated the incidence rate of HCL among Japanese patients with chronic lymphocytic leukemia, and related diseases. We identified 18 cases (33.3%) harboring the BRAF mutation among 54 patients diagnosed with, or suspected of having HCL. Of BRAF V600E-positive patients, 7 were only detected using the QP method, not by direct sequencing, whereas 11 were positive using both tests. In a larger cohort of Japanese patients diagnosed with chronic lymphoid leukemia or related diseases, the frequency of HCL was 4%. Patients with the BRAF V600E mutation had a significantly higher frequency of neutropenia, thrombocytopenia, and elevated soluble interleukin-2 receptor and common B-cell surface markers than patients without the mutation. Our results confirm that BRAF V600E-positive HCL is a relatively rare disorder in the Japanese leukemia patient population.

Three coexisting lymphomas in a single patient: composite lymphoma derived from a common germinal center B-cell precursor and unrelated discordant lymphoma

Composite lymphoma (CL) is a rare disorder defined as the coexistence of two or more distinct lymphoma subtypes at a single anatomic site. Discordant lymphoma (DL), which is the simultaneous occurrence of two or more distinct lymphoma subtypes at different sites, is also rare. CL complicated with DL involving three distinct subtypes of lymphoma in the same patient is an extremely rare disease. Clonal relationships in CL and DL are commonly investigated by molecular analysis using mutational status with t(14;18)BCL2/IgH translocation and immunoglobulin heavy chain variable-region (IgV_H) gene rearrangement. A 73-year-old woman was admitted to our hospital with systemic lymphadenopathy and was initially diagnosed with diffuse large B-cell lymphoma based on pathological features of the biopsied esophageal tumor. However, the results of inguinal lymph node biopsy led to a revised pathological diagnosis CL consisting of Hodgkin lymphoma and follicular lymphoma. Three distinct coexisting lymphomas were identified in this individual patient. Molecular analysis revealed CL derived from common germinal center B-cell precursors, while clonal relationship between CL and DL was not clarified. This case suggests a mechanism underlying B-cell lymphoma pathogenesis involving two pivotal somatic mutations, t(14;18)BCL2/IgH translocation and IgV_H rearrangement.

Elderly Patients With Chronic Myeloid Leukemia Benefit From a Dasatinib Dose as Low as 20 mg

BACKGROUND

The clinical outcomes of patients with chronic myeloid leukemia (CML) treated with BCR-ABL tyrosine kinase inhibitors has improved markedly; however, the occurrence of adverse events (AEs) means that elderly patients often cannot be administered the standard dose. Nevertheless, some patients treated with low doses of tyrosine kinase inhibitor have achieved good molecular responses.

PATIENTS AND METHODS

We retrospectively analyzed the efficacy and safety of low-dose dasatinib treatment of elderly CML patients. The study enrolled 21 patients with newly diagnosed, imatinib-resistant, or imatinib-intolerant chronic phase CML. All the patients were aged ≥ 65 years and received dasatinib at a dose of < 100 mg/day. Of these 21 patients, 77% had newly diagnosed CML.

RESULTS

Overall, 91% and 72% of patients received a mean dasatinib dose of ≤ 50 mg and ≤ 20 mg, respectively. A molecular response of MR³ (major molecular response, indicating > 3 log reduction in the number of leukemic cells), MR⁴, and MR^4.5 were achieved in 96%, 77%, and 62% of the patients, respectively. Of the 15 patients who received a mean dose of ≤ 20 mg, 94% achieved a major molecular response, and 74% achieved MR⁴. The most common nonhematologic AE was plural effusion (29%), which was controlled by diuretics and regulating the drug dose.

CONCLUSION

Low-dose (eg, ≤ 20 mg) dasatinib therapy generates an adequate molecular response in most elderly patients with chronic phase CML without causing severe AEs.

The MEK inhibitor trametinib separates murine graft-versus-host disease from graft-versus-tumor effects

The efficacy of allogeneic hematopoietic stem cell transplantation for hematologic malignancies is limited by the difficulty in suppressing graft-versus-host disease (GVHD) without compromising graft-versus-tumor (GVT) effects. We previously showed that RAS/MEK/ERK signaling depends on memory differentiation in human T cells, which confers susceptibility to selective inhibition of naive T cells. Actually, antineoplastic MEK inhibitors selectively suppress alloreactive T cells, sparing virus-specific T cells in vitro. Here, we show that trametinib, a MEK inhibitor clinically approved for melanoma, suppresses GVHD safely without affecting GVT effects in vivo. Trametinib prolonged survival of GVHD mice and attenuated GVHD symptoms and pathology in the gut and skin. It inhibited ERK1/2 phosphorylation and expansion of donor T cells, sparing Tregs and B cells. Although high-dose trametinib inhibited myeloid cell engraftment, low-dose trametinib suppressed GVHD without severe adverse events. Notably, trametinib facilitated the survival of mice transplanted with allogeneic T cells and P815 tumor cells with no residual P815 cells observed in the livers and spleens, whereas tacrolimus resulted in P815 expansion. These results confirm that trametinib selectively suppresses GVHD-inducing T cells while sparing antitumor T cells in vivo, which makes it a promising candidate for translational studies aimed at preventing or treating GVHD.

Rituximab-containing Chemotherapy (R-CHOP)-induced Kaposi's Sarcoma in an HIV-negative Patient with Diffuse Large B Cell Lymphoma

Rituximab treatment may cause or exacerbate Kaposi's sarcoma (KS) in patients with human immunodeficiency virus (HIV)-associated multicentric Castleman's disease. Despite the widespread use of rituximab, rituximab-induced KS has not yet been reported in HIV-negative patients with diffuse large B cell lymphoma (DLBCL). We herein report a case of KS that developed after undergoing rituximab-containing chemotherapy in an HIV-negative patient with DLBCL. An 84-year-old man who received rituximab-containing chemotherapy for the treatment of DLBCL developed severe infection, and subsequently KS. Our observations indicate that serious infections under rituximab treatment may trigger KS. KS should therefore be considered when skin tumors appear in lymphoma patients receiving rituximab-containing chemotherapy.

A novel frameshift mutation in exon 4 causing a deficiency of high-molecular-weight kininogen in a patient with splenic infarction

High-molecular-weight kininogen (HMWK) deficiency is a very rare hereditary disorder. We herein report a case of HMWK deficiency with splenic infarction. The HMWK activity of the proband was markedly decreased (0.9%). Direct sequencing of his HMWK gene showed a homozygous "TC" insertion at c523-524 in exon 4. This insertion led to an amino acid substitution, Ser175Ser, resulting in a frameshift mutation and a premature stop codon in amino acid 183. Furthermore, the HMWK activity was also reduced in the patient's three children, who exhibited the heterozygous "TC" insertion at c523-524 in exon 4. This is the first report of this gene alteration in a patient with HMWK deficiency.

Human herpesvirus 6 (HHV-6) reactivation and HHV-6 encephalitis after allogeneic hematopoietic cell transplantation: a multicenter, prospective study

BACKGROUND

The epidemiology of human herpesvirus 6 (HHV-6) encephalitis after allogeneic hematopoietic cell transplantation (HCT) and its relationship with HHV-6 reactivation have not been sufficiently characterized.

METHODS

This prospective, multicenter study of 230 allogeneic HCT recipients investigated the epidemiology of HHV-6 reactivation and HHV-6 encephalitis. Plasma HHV-6 DNA load was prospectively evaluated twice weekly until 70 days after HCT.

RESULTS

Cumulative incidence of positive HHV-6 DNA and high-level HHV-6 reactivation (plasma HHV-6 DNA ≥10(4) copies/mL) at day 70 after HCT was 72.2% and 37.0%, respectively. Multivariate analysis identified myeloablative conditioning (hazard ratio [HR], 1.9; P = .004), umbilical cord blood transplantation (UCBT) (HR, 2.0; P = .003), and male sex (HR, 1.6; P = .04) as risk factors for displaying high-level HHV-6 reactivation. HHV-6 encephalitis occurred in 7 patients, and cumulative incidence at day 70 was 3.0%. None of the144 patients without high-level HHV-6 reactivation and 7 of 86 patients (8.1%) with high-level HHV-6 reactivation developed HHV-6 encephalitis (P = .0009). Prevalence of HHV-6 encephalitis was significantly higher among patients receiving UCBT than in patients with other sources (cumulative incidence at day 70, 7.9% vs 1.2%, P = .008). In each of 7 patients with HHV-6 encephalitis, central nervous system (CNS) symptoms developed concomitant with peak plasma HHV-6 DNA (range, 21 656-433 639 copies/mL).

CONCLUSIONS

High levels of plasma HHV-6 DNA are associated with higher risk of HHV-6 encephalitis. UCBT is a significant risk factor for HHV-6 encephalitis. HHV-6 encephalitis should be considered if CNS dysfunction develops concomitant to high-level plasma HHV-6 DNA after allogeneic HCT.

Expressed sequence tags from persimmon at different developmental stages

Persimmon (Diospyros kaki Thunb.) is an important fruit in Asian countries, where it is eaten as a fresh fruit and is also used for many other purposes. To understand the molecular mechanism of fruit development and ripening in persimmon, we generated a total of 9,952 expressed sequence tags (ESTs) from randomly selected clones of two different cDNA libraries. One cDNA library was derived from fruit of "Saijo" persimmon at an early stage of development, and the other from ripening fruit. These ESTs were clustered into 6,700 non-redundant sequences. Of the 6,700 non-redundant sequences evaluated, the deduced amino acid sequences of 4,356 (65%) showed significant homology to known proteins, and 2,344 (35%) showed no significant similarity to any known proteins in Arabidopsis databases. We report comparison of genes identified in the two cDNA libraries and describe some putative genes involved in proanthocyanidin and carotenoid synthesis. This study provides the first global overview of a set of genes that are expressed during fruit development and ripening in persimmon.

Cryopreservation of persimmon (Diospyros kaki Thunb.) by vitrification of dormant shoot tips

Shoot tips excised from dormant axillary buds of persimmon (Diospyros kaki Thunb.) were cryopreserved by vitrification. These excised shoot tips were dehydrated in a highly concentrated vitrification solution for 20 min at 25°C and then plunged directly into liquid nitrogen. After rapid warming in water at 40°C, the shoot tips were rinsed in a 1.2 M sucrose solution for 20 min and then plated on a solidified culture medium. Successfully vitrified shoot tips resumed growth within 10 days of plating and developed shoots within 3 weeks without intermediary callus formation. This simple protocol was successfully applied to the 16 cultivars found in the temperate zone. The average rate of shoot formation was 89%. Even the subtropical species of Diospyros demonstrated a very high recovery growth when the shoot tips had been previously osmoprotected with a mixture of 2 M glycerol plus 0.4 M sucrose for 20 min following sucrose preculture. Little or no contamination occurred in the cryopreserved shoot tips excised from sterilized winter axillary buds. Thus, this simple and reliable vitrification protocol using dormant shoot tips appears to be promising as a routine method for the long-term conservation of Diospyros germplasm of both temperate and subtropical origins.