Heiichiro Hamada

Reduced Frequency, Diversity, and Function of Human T Cell Leukemia Virus Type 1-Specific CD8+ T Cell in Adult T Cell Leukemia Patients

Human T cell lymphotropic virus type 1 (HTLV-1)-specific CTL are thought to be immune effectors that reduce the risk of adult T cell leukemia (ATL). However, in vivo conditions of anti-HTLV-1 CTL before and after ATL development have yet to be determined. To characterize anti-HTLV-1 CTL in asymptomatic HTLV-1 carriers (AC) and ATL patients, we analyzed the frequency and diversity of HTLV-1-specific CD8+ T cells in PBMC of 35 AC and 32 ATL patients using 16 distinct epitopes of HTLV-1 Tax or Env/HLA tetramers along with intracellular cytolytic effector molecules (IFN-γ, perforin, and granzyme B). Overall frequency of subjects possessing Tax-specific CD8+ T cells was significantly lower in ATL than AC (53 vs 90%; p = 0.001), whereas the difference in Env-specific CD8+ T cells was not statistically significant. AC possessed Tax11–19/HLA-A*0201-specific tetramer+ cells by 90% and Tax301–309/HLA-A*2402-specific tetramer+ cells by 92%. Some AC recognized more than one epitope. In contrast, ATL recognized only Tax11–19 with HLA-A*0201 and Tax301–309 with HLA-A*2402 at frequencies of 30 and 55%. There were also significant differences in percentage of cells binding Tax11–19/HLA-A*0201 and Tax301–309/HLA-A*2402 tetramers between AC and ATL. Anti-HTLV-1 Tax CD8+ T cells in AC and ATL produced IFN-γ in response to Tax. In contrast, perforin and granzyme B expression in anti-HTLV-1 CD8+ T cells of ATL was significant lower than that of AC. Frequency of Tax-specific CD8+ T cells in AC was related to proviral load in HLA-A*0201. These results suggest that decreased frequency, diversity, and function of anti-HTLV-1 Tax CD8+ T cell clones may be one of the risks of ATL development.

Matrix metalloproteinase inhibitor reduces apoptosis induction of bone marrow cells in MDS‐RA

Abstract:  Background and objectives: We examined the involvement of apoptosis with myelodysplastic syndrome (MDS) accompanied by peripheral cytopenias despite normo‐hypercellular bone marrow. Materials and methods: Bone marrow smears from 31 patients with MDS‐refractory anemia (RA) and five normal controls were stained using the in situ end labeling (ISEL) method. Next, the inhibitory effects of a caspase‐3 inhibitor, matrix metalloproteinase inhibitor (MMPI), anti‐tumor necrosis factor (TNF)‐α or anti‐Fas antibody upon the apoptosis induction in overnight cultures of bone marrow cells from the patients were examined. Further, TNF‐α, transforming growth factor (TGF)‐β and soluble Fas ligand (sFasL) concentrations in culture supernatants of the cells were assessed by enzyme‐linked immunosorbent assay (ELISA). Results: The incidence of ISEL‐positive cells among MDS patients was significantly higher than in normal controls (50.8 ± 14.0% vs. 11.3 ± 2.4%; P < 0.0001). A caspase‐3 inhibitor reduced significantly the ISEL‐positive rates (32.6 ± 15.2% vs. 50.2 ± 16.5%; P < 0.0001). Anti‐TNF‐α or anti‐Fas antibody reduced the ISEL‐positive rates significantly (28.2 ± 6.0%, 29.2 ± 5.8%, vs. 44.2 ± 3.4%, P < 0.001, P = 0.001, respectively). KB‐R7785 also significantly decreased the ISEL‐positive rates (18.0 ± 9.3% vs. 43.6 ± 14.0%; P < 0.0001). The concentration of TNF‐α was significantly reduced by KB‐R7785 (P < 0.05), whereas that of TGF‐β was not. Concentration of sFasL was under detectable level in the present assay system. The derivatives of KB‐R7785 that can be administrated orally showed inhibitory effect on apoptosis induction as well. Conclusions: These findings suggest that MMPIs inhibits the apoptosis induction of MDS bone marrow cells via the inhibition of TNF‐α and probably sFasL secretion, and that MMPIs can be used to control the abnormal induction of apoptosis in MDS.

A case of renal juxtaglomerular cell tumor: usefulness of segmental sampling to prove autonomic secretion of the tumor.

A 27-year-old female patient had been treated for hypertension with conventional therapy for years, because renal vein renin levels failed to show lateralization in renal venous samplings and a renal juxtaglomerular cell tumor (RJGCT) had gone undiagnosed. Abdominal computed tomography revealed a mass at the middle of the right kidney. The right renal venogram demonstrated distinct segmental veins from the upper pole and from the middle and lower poles in the right kidney. On segmental renin sampling from each renal vein, the plasma renin concentration (PRC) of the segmental veins from the middle and lower poles was higher than that from other sites. We diagnosed RJGCT of the right kidney and performed right-sided nephrectomy. After the resection, the PRC rapidly decreased. Immunohistochemical studies using antihuman renin antibodies revealed positive staining of the tumor cells. It is an important strategy to make a segmental sampling at the site as close as possible to the RJGCT.

High prevalence of human T-lymphotropic virus type I carriers among patients with myelodysplastic syndrome refractory anemia with excess of blasts (RAEB), RAEB in transformation and acute promyelocytic leukemia

We examined human T-lymphotropic virus type I (HTLV-I) infection among patients with myelodysplastic syndrome (MDS), refractory anemia with excess of blasts (RAEB)/RAEB in transformation (RAEBt) and acute myelogenous leukemia (AML). The study population consisted of 151 patients: 46 with MDS RAEB/RAEBt and 105 with AML (M1, n = 15; M2, n = 39; M3, n = 18; M4, n = 19; M5, n = 9; M6, n = 3; M7, n = 2). As a reference, we examined 92 patients with refractory anemia (RA) and 405 patients with cardiovascular diseases (CVD). Thirteen patients with RAEB/RAEBt (28.3%), 11 with AML (11.6%), 27 with RA (29.3%), and 45 with CVD (11.0%) were positive for HTLV-I. Seven AML patients with HTLV-I infection had M3 acute promyelocytic leukemia (APL). The prevalences of HTLV-I infection among patients with RAEB/RAEBt (P < 0.001), APL (P = 0.001), and RA (P < 0.001) were significantly higher than that in patients with CVD. The prevalences of HTLV-I infection were still significantly higher in patients with RAEB/RAEBt (P = 0.007), APL (P = 0.017) and RA (P < 0.001) than in those with CVD matched by sex and age. Platelet counts and survival times of RAEB/RAEBt patients with infection were significantly lower than those of patients without infection.

Case of a patient with progressive adult T-cell leukemia/lymphoma treated successfully by reduced-intensity conditioning stem cell transplantation from an HLA-incompatible related donor.

A 61-year-old man with progressive adult T-cell leukemia/lymphoma (ATLL) successfully received reduced-intensity conditioning stem cell transplantation (RIST) without T-cell depletion (TCD) from his HLA-incompatible son, who had negative results for human T-lymphotropic virus type 1 (HTLV-1) (1-locus, 1-allele mismatch in the graft-versus-host [GVH] direction; 2-loci, 1-allele mismatch in the host-versus-graft direction), The preparatory regimen consisted of fludarabine, busulfan, and rabbit antithymocyte globulin. GVH disease (GVHD) prophylaxis consisted of short-term administration of methotrexate, tacrolimus, and methylprednisolone. The patient achieved complete donor chimerism on day 30 after transplantation.On approximately day 50 the patient started to experience steroid-refractory skin GVHD (grade IV), which was successfully managed with basiliximab (anti-CD25 monoclonal antibody) and mycophenolate mofetil (MMF). Serial analysis of HTLV-1 proviral load by quantitative polymerase chain reaction analysis using whole peripheral blood demonstrated undetectable levels from day 90. At the time of this writing the patient had been in complete remission for more than 16 months. The results in this case suggest the potential of non-TCD RIST from an HLA-incompatible relative donor as an alternative source of hematopoietic stem cells even for an elderly patient with advanced ATLL. In addition, basiliximab combined with MMF may be effective for the treatment of steroid-refractory skin GVHD without deteriorating the graft-versus-ATL effect.

High proviral load of human T-lymphotropic virus type I in patients with myelodysplastic syndrome carrying HLA-A26

Adult T cell leukemia (ATL) is a malignant disease etiologically combined with human T-lymphotropic virus type I (HTLV-I). However, the precise mechanism of leukemogenesis is still unknown, a breakdown in the immuno-surveillance system against HTLV-I infected T-lymphocytes is thought to be involved. The prevalence of a specific phenotype of human leukocyte antigen (HLA), A26, was reported to be unique in patients with ATL [1]. The allelic frequency of A26 among ATL, asymptomatic HTLV-I carriers, and healthy controls is 25.0%, 15.1% and 12.0%, respectively. The clinical characteristics of ATL are the diversity of disease appearance and patients are usually classified into four clinical subtypes: (i) acute; (ii) chronic; (iii) lymphoma; and (iv) smouldering [2]. In addition, recent understanding has revealed the existence of HTLV-I infected patients who have a high proviral load without monoclonal proliferation [3]. Some of these patients were reported in relation to HTLV-I related diseases [4], and others were described as asymptomatic carriers. Because HTLV-I infection may cause diseases other than ATL [5], the involvement of high proviral load state in the pathogenesis of such HTLV-I associated disease appears to be important. Myelodysplastic syndrome (MDS) is a hematological disease associated with hemopoietic insufficiency with morphological dysplasia of bone marrow cells [6]. One etiological feature of MDS is malignant transformation characterized by the frequent existence of chromosomal abnormalities, and the major prognostic event is progression to acute myelogenous leukemia (AML). Another feature is immunological attack of hemopoietic cells. The coincidence of AML with ATL was reported to be significantly frequent [7], and the prevalence of HTLV-I infection among MDS is higher than that among healthy controls [8]. Nevertheless, the prevalence of HTLV-I infection among MDS patients has been questioned [9,10], and the coincidence of MDS with ATL has been reported to be rare in some series [11,12]. We report three sequential MDS patients with HTLV-I infection carrying HLA-A26 and having a high proviral load. Three MDS patients (mean age 67.3 years, range 59 – 73 years; one female and two males) who visited our hospital from May 2000 to February 2002, were selected for analysis because they had a noticable percentage of abnormal lymphocytes in their peripheral white blood cells. All three patients had leukocytopenia, with a range of 2 – 3.2610/l. Their lymphocyte counts were below 4610/l and 0.04 – 0.13610/l of their leukocytes were abnormal (Figure 1A – C). They also had slight anemia, in the range 3.3 – 3.93610/l, and thrombocytopenia, in the range 60 – 91610/l. They had normal serum lactodehydrogenase and calcium levels.