Umbilical Cord Blood Transplantation Using Reduced-Intensity Conditioning without Antithymocyte Globulin in Adult Patients with Severe Aplastic Anemia.

Umbilical cord blood transplantation (UCBT) is a possible option for patients with aplastic anemia (AA) without a related or unrelated HLA-matched donor, particularly if immunosuppressive therapy (IST) has failed or transplantation is urgently needed. However, a higher rate of graft failure after UCBT remains a major problem, and the optimal conditioning regimen for stable engraftment after UCBT has not been established. Here we investigated 6 adult patients with AA who underwent UCBT using a reduced-intensity conditioning (RIC) regimen comprising fludarabine 125 mg/m2, cyclophosphamide 120 mg/kg, and 4 Gy of total body irradiation (Flu/CY/TBI4Gy) without antithymocyte globulin (ATG). Five patients underwent UCBT after IST failure, and 1 patient underwent UCBT as a first-line treatment due to a fulminant clinical finding of a neutrophil count of 0, despite granulocyte colony-stimulating factor administration. Regarding graft-versus-host disease (GVHD) prophylaxis, 2 patients received tacrolimus plus short-term methotrexate and 4 patients received tacrolimus plus mycophenolate mofetil, and all patients achieved sustained engraftment of both neutrophils and platelets, at a median of 17.5 days (range, 14 to 37 days) and 38.5 days (range, 31 to 86 days), respectively, with complete donor chimerism confirmed in all patients at a median of 14 days (range, 14 to 32 days). Three patients developed grade II acute GVHD (aGVHD), but grade III/IV aGVHD was not observed, whereas 4 patients developed chronic GVHD involving only skin. At the time of this report, all 6 patients were alive without the need for blood transfusion, at a median follow-up of 16 months (range, 12 to 131 months). Although further study is needed, our findings suggest that conditioning with Flu/CY/TBI4Gy without ATG might allow stable engraftment in UCBT for adults with AA.

Successful Cord Blood Stem Cell Transplantation for Primary Cutaneous CD8-positive Aggressive Epidermotropic Cytotoxic T-cell Lymphoma Complicated with Cerebral Infiltration.

A 16-year-old boy, who had been initially examined for bilateral blepharedema and slight eruption, presented with rapidly deteriorating symptoms in associating with headache and consciousness disturbance. He was diagnosed to have primary cutaneous CD8-positive aggressive epidermotropic cytotoxic T-cell lymphoma (PCAE-CTL) by a biopsy of the skin and brain. After whole-brain radiation and some courses of chemotherapy, cord blood transplantation was performed with myeloablative conditioning. After transplantation, the cerebral dysfunction gradually improved. Disease remission was confirmed by the disappearance of any abnormal findings on electroencephalogram and magnetic resonance imaging. PCAE-CTL is reported to be an extremely aggressive disease with a poor prognosis, but the timely performance of cord blood transplantation is considered to be a promising treatment strategy.

Crucial role of carbonic anhydrase IX in tumorigenicity of xenotransplanted adult T-cell leukemia-derived cells.

Carbonic anhydrase IX (CA9) is a membrane-associated carbonic anhydrase that regulates cellular pH, is upregulated in various solid tumors, and is considered to be a therapeutic target. Here, we describe the essential role of CA9 in the tumorigenicity of cells derived from human adult T-cell leukemia/lymphoma (ATL). We previously established the highly tumorigenic ST1-N6 subline from the ATL-derived ST1 cell line by serial xenotransplantation in NOG mice. In the present study, we first show that CA9 expression is strongly enhanced in ST1-N6 cells. We then sorted ST1 cells by high or low CA9 expression and established ST1-CA9high and ST1-CA9low sublines. ST1-CA9high cells, like ST1-N6 cells, were more strongly tumorigenic than ST1-CA9low or parental ST1 cells when injected into NOG mice. Knockdown of CA9 with shRNAs suppressed the ability of ST1-CA9high cells to initiate tumors, and the tumorigenicity of ST1 cells was significantly enhanced by introducing wild-type CA9 or a CA9 mutant with deletion of an intracytoplasmic domain. However, a CA9 with point mutations in the catalytic site did not increase the tumorigenicity of ST1 cells. Furthermore, we detected a small population of CA9+ CD25+ cells in lymph nodes of ATL patients. These findings suggest that CA9, and particularly its carbonic anhydrase activity, promotes the tumorigenicity of ATL-derived cells and may be involved in malignant development of lymphoma-type ATL.

Xenotransplantation elicits salient tumorigenicity of adult T-cell leukemia-derived cells via aberrant AKT activation.

The transplantation of human cancer cells into immunodeficient NOD/SCID/IL-2Rγc(null) (NOG) mice often causes highly malignant cell populations like cancer stem cells to emerge. Here, by serial transplantation in NOG mice, we established two highly tumorigenic adult T-cell leukemia-derived cell lines, ST1-N6 and TL-Om1-N8. When transplanted s.c., these cells formed tumors significantly earlier and from fewer initial cells than their parental lines ST1 and TL-Om1. We found that protein kinase B (AKT) signaling was upregulated in ST1-N6 and TL-Om1-N8 cells, and that this upregulation was due to the decreased expression of a negative regulator, INPP5D. Furthermore, the introduction of a constitutively active AKT mutant expression vector into ST1 cells augmented the tumorigenicity of the cells, whereas treatment with the AKT inhibitor MK-2206 attenuated the progression of tumors induced by ST1-N6 cells. Collectively, our results reveal that the AKT signaling pathway plays a critical role in the malignancy of adult T-cell leukemia-derived cells.

High thymidine kinase activity is a strong predictive factor for poor prognosis in peripheral T-cell lymphoma treated with cyclophosphamide, adriamycin, vincristine and prednisone.

The prognosis of patients with peripheral T-cell lymphoma (PTCL) treated with cyclophosphamide, adriamycin, vincristine and prednisone (CHOP) is poor, but their laboratory prognostic parameters had not previously been evaluated. We retrospectively reviewed 55 patients with newly diagnosed PTCL treated with CHOP from August 1999 to May 2009 at our institution. We analyzed six laboratory parameters, including thymidine kinase (TK) activity, to evaluate overall survival, which was the primary end-point. In multivariate analysis, the overall survival was significantly worse in patients with high TK activity (hazard ratio 34.8, 95% confidence interval [CI] 1.03-1176.23). The overall response rate among patients with high TK activity was 21.4%, significantly poorer compared with other parameters (p = 0.001). High TK activity predicts poor overall survival among patients with newly diagnosed PTCL treated with CHOP. Response to CHOP treatment is significantly decreased in patients with PTCL with high TK activity.

Lymphadenopathy of IgG4-related sclerosing disease: three case reports and review of literature.

Immunoglobulin (Ig) G4-related sclerosing disease is a recently described syndrome characterized by lymphoplasmacytic infiltration of exocrine glands or extranodal tissues and elevated serum IgG4. We report three cases of lymphadenopathy secondary to IgG4-related sclerosing disease. Histologic features of involved lymph nodes included interfollicular immunoblasts and plasma cells, similar to Castleman's disease. The percentage of IgG4-/IgG-positive plasma cells in the three patients was markedly elevated (30, 50, and 60%). Administration of prednisolone led to remission in every case. One of three cases was consulted to our hospital due to suspected diagnosis of angioimmunoblastic T cell lymphoma (AITL). The case demonstrates many clinical and pathologic similarities between IgG4-related sclerosing disease and AITL. Pathological similarities between AITL and the lymphoplasmacytic subtype of IgG4-sclerosing disease have recently been reported. It is important to accurately diagnose IgG4-related lymphadenopathy given its ready response to steroid therapy and the potential for misdiagnosing lymphoma on clinical grounds.

Gemtuzumab ozogamicin-induced long-term remission in a woman with acute myelomonocytic leukemia and bone marrow relapse following allogeneic transplantation.

A 56-year-old woman with acute myelomonocytic leukemia underwent myeloablative allogeneic hematopoietic stem cell transplantation (allo-SCT) from a matched unrelated donor in her first complete remission (CR). Veno-occlusive disease (VOD) prophylaxis consisted of low-dose heparin and ursodeoxycholic acid. Graft-versus-host disease (GVHD) prophylaxis comprised tacrolimus and short-term methotrexate. On day 14, VOD developed, but gradually resolved with supportive therapy. On day 58, she showed grade II acute GVHD, but this resolved spontaneously. On day 140, she developed hematological relapse with 40.2% marrow infiltration of CD33-positive blasts. Following the discontinuation of tacrolimus, gemtuzumab ozogamicin (GO) was administered. After GO administration, the patient exhibited mild VOD and severe pancytopenia with a sustained high fever for 6 weeks without evident infection. Bone marrow examination revealed severe hypoplastic marrow with 1.3% blasts 4 weeks after GO administration. Although transfusion-dependent pancytopenia persisted for 8 months after GO administration, bone marrow examination revealed the recovery of normal hematopoietic cells with 0.8% blasts. The patient has remained in CR with incomplete blood count recovery for 7 years following GO administration. Although the standard treatment for acute myeloid leukemia relapse after allo-SCT still remains to be established, GO may be a promising option.