Shuichi Ohta

Expression of HLA‐C‐specific natural killer cell receptors (CD158a and CD158b) on peripheral blood mononuclear cells after allogeneic bone marrow transplantation

We investigated the expression of natural killer cell receptors (NKRs) for HLA‐C on peripheral blood mononuclear cells (PBMCs) in 23 allogeneic bone marrow transplantation (allo‐BMT) patients to analyse the role of NKRs in alloresponse concerning graft‐versus‐host disease (GVHD). CD158a expression was low and there was little change in the expression after allo‐BMT. Also, there was no difference in the proportion of CD158a+/CD3− after allo‐BMT. In contrast, the proportion of CD158b+/CD3− cells, mainly NK cells, increased in the early stage (< 2 months) after allo‐BMT and then gradually decreased (3.3 ± 2.6% before BMT vs. 15.4 ± 8.6% in the early stage after BMT, 8.5 ± 4.9% during the period 3–6 months after BMT and 7.0 ± 3.0% > 6 months after BMT; P < 0.05). However, CD158b expression on CD3+ T cells increased 3 months after allo‐BMT (1.1 ± 1.1% before BMT vs. 5.1 ± 7.7% during the period 3–6 months after BMT and 3.0 ± 2.4% > 6 months after BMT, P < 0.05). The highest percentages of CD158 expression in patients without chronic GVHD (cGVHD) and those with cGVHD were compared. The percentage of CD158b+/CD3+ cells and also that of CD158b+/CD8+ cells were significantly increased in patients with cGVHD compared with those in patients without cGVHD (2.6 ± 2.0% vs. 8.0 ± 11.2% and 2.3 ± 1.5% vs. 8.3 ± 11.7% respectively; P < 0.05). The exact clinical relevance of these CD158b‐expressing cells is not clear. However, there is an interesting possibility that CD158b‐expressing cells play some role in the regulation of GVHD after allo‐BMT.

Increased Proportion of HLA-Class-I-Specific Natural Killer Cell Receptors (CD94) on Peripheral Blood Mononuclear Cells after Allogeneic Bone Marrow Transplantation

In the present study, we investigated the inhibitory natural killer cell receptor (NKR) expression of CD94/NKG2A on PBMC after allogeneic bone marrow transplantation (BMT). The proportion of CD94 expression on PBMC was higher in patients without chronic graft-versus-host disease (cGVHD) and also in cGVHD patients with good response to conventional immunosuppressive therapy than in cGVHD patients with poor response. Also, the proportions of CD94+/CD3+ cells and CD94+/CD8+ cells were higher in cGVHD patients showing good response. In addition, the proportion of NKG2A-expressing cells was higher in patients without cGVHD than in patients with cGVHD. Therefore, chronic allostimulation after allo-BMT may augment the proportion of CD94/NKG2A-positive cells, and these cells may play some role in the regulation of alloresponse in some patients.

Sequential analysis of HLA-C-specific killer cell inhibitory receptor (CD158b) expressing peripheral blood mononuclear cells during chronic graft-versus-host disease.

We have sequentially investigated the expression of natural killer cell inhibitory receptors (KIRs) for HLA-C (CD158b) on peripheral blood mononuclear cells (PBMC) in three patients with extensive chronic graft-versus-host disease (cGVHD) after allogeneic bone marrow transplantation (alloBMT). Clinical symptoms of cGVHD were not cured and worsened in the first patient whose CD158b-positive cells increased to 18.5% during cGVHD and decreased to 9.4% at 8 months after transplantation. On the other hand, cGVHD was cured and did not relapse in the second patient whose CD158b-positive cells increased up to 45.9% during cGVHD and sustained 19.4% at 8 months after transplantation. In contrast, CD158b-positive cells were less than 10% during the course of cGVHD in the third patient, and her cGVHD did not respond to treatment. Therefore, it appears that chronic allostimulation augments the expansion of CD158b-positive cells and these expanded CD158b-positive cells may have some role in the control of alloresponse in some patients. Bone Marrow Transplantation (2000) 26, 287–290.

A Multicenter Retrospective Study of Mogamulizumab Efficacy in Adult T-Cell Leukemia/Lymphoma.

Micro‐Abstract Mogamulizumab recently became available for the treatment of adult T‐cell leukemia/lymphoma (ATL). We conducted a multicenter retrospective study of the efficacy of mogamulizumab for ATL treatment in patients in Japan and found that mogamulizumab is an effective therapeutic strategy in ATL. Some concern exists that the use of mogamulizumab in patients undergoing hematopoietic stem cell transplantation patients might cause severe graft‐versus‐host disease. Determining the optimum number of mogamulizumab administrations should be a priority for future studies. Background: Mogamulizumab, a defucosylated humanized monoclonal antibody targeting C‐C chemokine receptor 4, recently became available for the treatment of adult T‐cell leukemia/lymphoma (ATL). We conducted a multicenter retrospective study of the efficacy of mogamulizumab in ATL treatment in patients on Hokkaido Island, Japan. Materials and Methods: A total of 125 patients with ATL treated from January 2010 to December 2014 in 20 hospitals affiliated with the Hokkaido Hematology Study Group were enrolled in the present retrospective study. Results: Of the 125 ATL patients, 62 (46.6%) presented with the acute type, 51 (38.3%) with the lymphoma type, and 12 (9.0%) with the chronic type; the latter group included 7 unfavorable chronic cases. The median age at diagnosis was 68 years (range, 35‐86 years). The median survival for those with acute, lymphoma, and unfavorable chronic types was 302, 279, and 921 days, respectively. Advanced age, high lactate dehydrogenase level, poor performance status (3‐4), and the existence of B symptoms were unfavorable prognostic factors for overall survival (OS). Survival rate calculated from the day of diagnosis was significantly higher in patients treated with mogamulizumab. The OS of individuals receiving hematopoietic stem cell transplantation (HSCT) was superior to that of the non‐HSCT group. The median interval between the last mogamulizumab dose and allogeneic HSCT was 38 days (range, 21‐53 days). Of the 22 HSCT recipients who were not treated with mogamulizumab, overall acute graft‐versus‐host disease (aGVHD) and grade III‐IV aGVHD occurred in 12 (54.5%) and 3 (13.6%) patients, respectively. However, overall aGVHD and grade III‐IV aGVHD developed in 8 (88.9%) and 3 (33.3%) of the 9 HSCT recipients treated with mogamulizumab, respectively. Conclusion: Mogamulizumab improves OS in patients with ATL, although its use in HSCT patients might trigger severe GVHD. Determining the optimal pre‐HSCT mogamulizumab treatment regimen is thus a priority.

Analysis of T-cell repertoire and mixed chimaerism in a patient with aplastic anaemia after allogeneic bone marrow transplantation

Summary. We analysed 26 T‐cell receptor (TCR) β chain subfamilies (VB) of a patient with aplastic anaemia (AA) who underwent allogeneic bone marrow transplantation (allo‐BMT). The patient developed pancytopenia at d 80. The patients T cells were skewed in 10 of 26 TCR‐VB on d 83. These TCR‐VB, especially VB15, which were almost entirely CD8‐positive cells, were skewed throughout her clinical course. Chimaerism analysis of the CD8‐positive cells indicated that they were of recipient origin. Therefore, some immune responses induced by the recipient CD8‐positive T cells had an important role in pancytopenia in AA patients after allo‐BMT.

Ciprofloxacin inhibits lipopolysaccharide-induced toll-like receptor-4 and 8 expression on human monocytes derived from adult and cord blood

Dear Editor, Lipopolysaccharide (LPS) interacts with immune cells by binding to CD14 molecules and then interacts with toll-like receptor (TLR)-4 on monocytes and dendritic cells [1–3]. On the other hand, TLR8 recognizes viral single-stranded RNA (ssRNA) [4]. Therefore, TLR4 is involved in immunological events during bacterial infection, and TLR8 is involved in immunological events during viral infection. Ciprofloxacin (CIP), a fluorinated 4-quinolone, is one of the quinolone antibiotics. CIP reduces the population of intestinal bacteria and influences the development of acute graft-vs-host disease (GVHD) after allogeneic bone marrow transplantation for hematological malignancies [5]. In addition, CIP has modulatory actions on immune and inflammatory responses, such as inhibition of the production of tumor necrosis factor (TNF)-α in LPS-stimulated peripheral blood mononuclear cells (PBMC) [6]. The mechanisms underlying the effects of quinolones on immune modulation might depend on the regulation of intracellular cAMP and NF-kB. CIP induces the production of prostaglandin E2 and increases intracellular cAMP levels. A hyperresponse to LPS by monocytes induces symptoms of septic shock, and CIP might therefore contribute to the attenuation of these symptoms after severe infection [7]. Cord blood contains more naive T cells and Treg precursor cells than adult blood [8]. In addition, it has been reported that there is a profound defect in IL-12 (p70) synthesis and an increased release of IL-10 in cord blood exposed to LPS compared to those in adult blood [9]. These facts might be relevant to the increased vulnerability of human newborns to intracellular pathogens and the low incidence of GVHD after cord blood transplantation (CBT). In this study, we analyzed TLR4, TRL8, ICAM-1, and LFA-1 expression on the surface of CD14-positive monocytes and TLR4, TLR8, and TNF-α mRNA expression after LPS stimulation with CIP using adult PBMC and cord blood mononuclear cells (CB). Normal adult PBMC and cord blood units were obtained from healthy donors with informed consent from Hokkaido Red Cross Blood Center Sapporo. Cells (1×10/ml) were cultured for 3 days with 10 μg/ml LPS (Escherichia coli 055: B5, EMD Bioscience, La Jolla, CA, USA) in RPMI-1640 with 10% fetal calf serum in the presence or absence of 50 μg/ ml CIP (kindly provided by Bayer Yakuhin, Osaka, Japan). After 3 days of culture, cells were harvested and stained with FITC-conjugated anti-TLR4 (HTA125; Santa Cruz Biotechnology, Santa Cruz, CA, USA), anti-LFA-1 (HI111; Becton Dickinson, San Diego, CA, USA), and anti-ICAM-1 (84H10; Immunotech, Marseille, France) monoclonal antibody (mAb) and with FITC-conjugated goat anti-mouse Ig G1 (STAR81F; Serotec, Oxford, UK) as a secondary antibody for anti-TLR8 (44C143; IMGENEX, San Diego, CA, USA) mAb and PEconjugated anti-CD14 (MoP9; Becton Dickinson) mAb. Mean fluorescence intensity (MFI) for TRL4, TRL8, ICAM-1, and LFA-1 on CD14-positive monocytes was analyzed using a fluorescence-activated cell sorter (FACS) Ann Hematol (2008) 87:229–231 DOI 10.1007/s00277-007-0363-x

Plural light chains in a single plasma cell of a monoclonal gammopathy undetermined significance case: An ultrastructural study

A 44-year-old man was found to have M-proteins of IgG consisting of κ- and λ-chains in serum without lymphadenopathy or splenomegaly. The serum concentrations of IgG, IgA and IgM were within normal limits. Bone marrow examination showed normal cellular marrow containing 6.3% of plasma cells with no abnormal features. No chromosomal abnormality was observed at all. The patient was diagnosed as having monoclonal gammopathy of undetermined significance. The bone marrow plasma cells possessed free κ- and λ-chains in Golgi apparatus, rough endoplasmic reticula and cytoplasmic matrices. Plural light chains were simultaneously produced with the same heavy chain in a plasma cell by immunoelectron microscopy. This is the first report in the world of a monoclonal gammopathy of undetermined significance producing plural light chains with the same heavy chain.

Additional cytogenetic abnormalities with Philadelphia chromosome-positive acute lymphoblastic leukemia on allogeneic stem cell transplantation in the tyrosine kinase inhibitor era

Cytogenetic abnormalities are well known and powerful independent prognostic factors for various hematologic disorders. Although the combination of chemotherapy with tyrosine kinase inhibitor (TKI) is now considered the standard of care in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia, little is known about the impact of additional cytogenetic abnormalities (ACAs). Therefore, we retrospectively evaluated 1375 adult patients who underwent their first allogeneic hematopoietic stem cell transplantation in the TKI era. In this study, 224 patients had ACAs (16.3%). The ACAs that were seen in more than 20 cases (1.5%) were as follows: -7, der(22), der(9), +8, and +X. Overall survival at 4 years was 56.9% (95% confidence interval [CI], 49.4% to 63.7%) in the group with ACAs and 60.5% (95% CI, 57.3% to 63.5%) in the group without ACAs (P = .266). The cumulative incidence of relapse at 4 years was 28.9% (95% CI, 22.6% to 35.6%) in the group with ACAs and 21.9% (95% CI, 19.4% to 24.6%) in the group with Ph alone (P = .051). In multivariate analyses there were no statistically significant differences in the risk of overall mortality or risk of relapse between the groups with and without ACAs. In the subgroup analyses of specific ACAs, although the presence of +8 was associated with a higher relapse rate in univariate and multivariate analyses, no specific ACA was associated with poor overall survival. Further studies will be needed to verify the impact of specific ACAs on transplantation outcomes.