Kenjiro Kamezaki

Monitoring of cytomegalovirus reactivation after allogeneic stem cell transplantation: comparison of an antigenemia assay and quantitative real-time polymerase chain reaction.

Cytomegalovirus (CMV) antigenemia and quantitative real-time polymerase chain reaction (PCR) were compared for monitoring of CMV reactivation after allogeneic stem cell transplantation. The number of CMV antigen-positive cells by the antigenemia assay and the level of CMV DNA by real-time PCR correlated well. The sensitivity and specificity of the antigenemia assay was 55.4% and 95.5%, respectively, using real-time PCR as the reference standard. The probability of positive antigenemia at day 100 was 76.5%, with a median of first detection at day 37 in 51 patients, compared with a positive PCR of 84.3% and day 33, respectively. When HLA-identical sibling donor transplant recipients and other donor transplant recipients were analyzed separately, there was no difference between the two tests. However, temporal patterns of first detection of CMV antigen-positive cells and CMV DNA differed between HLA-identical and alternative recipients; patients without CMV (29%) or with sporadic positive PCR results (14%) were more common in HLA-identical sibling transplants, whereas patients with simultaneous antigenemia and positive PCR occurred more in alternative transplants (48%). Two of 51 patients (4%) developed CMV colitis despite antigenemia-guided prophylaxis, but both were successfully treated with ganciclovir. Although PCR is more sensitive than antigenemia, both tests are useful in the early detection of CMV after allogeneic stem cell transplantation.

High Incidence of Human Herpes Virus 6-Associated Encephalitis/Myelitis following a Second Unrelated Cord Blood Transplantation

Human herpes virus (HHV)6-associated limbic encephalitis and/or myelitis is one of the life-threatening central nervous system complications following allogeneic hematopoietic stem cell transplantation (HSCT). Recent reports have shown significant correlations of these complications with unrelated cord blood transplantation (UCBT). We retrospectively analyzed 228 allogeneic HSCT recipients in our single institution; 13 patients (5.7%) were diagnosed with HHV6-associated encephalitis/myelitis. This complication was documented in 8 of 51 UCBT recipients (15.7%) and 5 of 177 recipients (2.8%) transplanted with bone marrow or peripheral blood stem cells, indicating a higher incidence of this complication occurring in UCBT recipients (P = .0005). In addition, HHV6-associated encephalitis/myelitis occurred more frequently in recipients who underwent 2 or more HSCTs (7 of 59 recipients [11.9%]), compared to those who received only 1 HSCT (6 of 169 recipients [3.6%], P = .018). Of note, the incidence of this complication increased to 28.6% (6 of 21 recipients), when the analysis was restricted to a second or more UCBT recipients. All 13 patients presented preengraftment immune response prior to the onset of encephalitis. Two patients manifested typical symptoms at the onset of HHV6-associated encephalitis/myelitis, such as memory dysfunction, disorientation, and consciousness disturbance. However, 4 patients presented only with dysesthesia and pruritus, described as typical manifestations of patients with calcineurin-inhibitor-induced pain syndrome (CIPS), and the remaining 7 showed both symptoms, indicating that CIPS-like symptoms might be manifestations of HHV6-associated myelitis. Thus, physicians should be alert to this rare but often fatal complication, particularly for those who receive 2 or more HSCTs using UCB.

Signal Transducers and Activators of Transcription 3 Augments the Transcriptional Activity of CCAAT/Enhancer-binding Protein α in Granulocyte Colony-stimulating Factor Signaling Pathway

The Janus kinase (Jak)-Stat pathway plays an essential role in cytokine signaling. Granulocyte colony-stimulating factor (G-CSF) promotes granulopoiesis and granulocytic differentiation, and Stat3 is the principle Stat protein activated by G-CSF. Upon treatment with G-CSF, the interleukin-3-dependent cell line 32D clone 3(32Dcl3) differentiates into neutrophils, and 32Dcl3 cells expressing dominant-negative Stat3 (32Dcl3/DNStat3) proliferate in G-CSF without differentiation. Gene expression profile and quantitative PCR analysis of G-CSF-stimulated cell lines revealed that the expression of C/EBPα was up-regulated by the activation of Stat3. In addition, activated Stat3 bound to CCAAT/enhancer-binding protein (C/EBP)α, leading to the enhancement of the transcription activity of C/EBPα. Conditional expression of C/EBPα in 32Dcl3/DNStat3 cells after G-CSF stimulation abolishes the G-CSF-dependent cell proliferation and induces granulocytic differentiation. Although granulocyte-specific genes, such as the G-CSF receptor, lysozyme M, and neutrophil gelatinase-associated lipocalin precursor (NGAL) are regulated by Stat3, only NGAL was induced by the restoration of C/EBPα after stimulation with G-CSF in 32Dcl3/DNStat3 cells. These results show that one of the major roles of Stat3 in the G-CSF signaling pathway is to augment the function of C/EBPα, which is essential for myeloid differentiation. Additionally, cooperation of C/EBPα with other Stat3-activated proteins are required for the induction of some G-CSF responsive genes including lysozyme M and the G-CSF receptor.

Long-term outcomes of autologous PBSCT for peripheral T-cell lymphoma: retrospective analysis of the experience of the Fukuoka BMT group

Peripheral T-cell lymphoma (PTCL) is generally characterized by poor prognosis after conventional chemotherapy compared with aggressive B-cell lymphoma. To elucidate the role of high-dose chemotherapy (HDCT) with auto-SCT, we retrospectively analyzed the outcomes of 39 patients with PTCL who received HDCT and auto-SCT between 1990 and 2005. Eleven patients were histologically typed as angioimmunoblastic, nine as anaplastic large-cell lymphoma, seven as natural killer/T-cell lymphoma and twelve as PTCL unspecified. Clinical conditions at transplantation were complete response (CR) in 27 patients and non-CR in 12 patients. Thirty-two patients received a pre-transplant conditioning regimen (MCEC) comprising ranimustine, carboplatin, etoposide and CY, and seven did other TBI-based regimens. Rapid engraftment was obtained in all cases, and transplant-related death was not seen. An estimated 5-year OS was 62.1% with a median follow-up of 78 months. The 5-year OS was significantly higher in patients transplanted during complete response than in those during other disease status (71.4% vs 27.3%, P=0.046). HDCT supported by auto-SCT may therefore be effective as consolidation in CR for PTCL treatment.

Toxoplasmosis encephalitis following severe graft‐vs.‐host disease after allogeneic hematopoietic stem cell transplantation: 17 yr experience in Fukuoka BMT group

Toxoplasmosis is a rare but rapidly fatal complication that can occur following hematopoietic stem cell transplantation (HSCT). Over a 17‐yr period at our institutions, a definite diagnosis of toxoplasmosis was made in only two of 925 allogeneic HSCT recipients (0.22%) and none of 641 autologous HSCT recipients. These two patients received a conventional conditioning regimen followed by transplantation from an HLA‐matched donor; however, they developed severe graft‐vs.‐host disease, which required intensive immunosuppressive therapy. Despite prophylactic treatment with trimethoprim/sulfamethoxazole, their immunosuppressive state, as indicated by a low CD4+ cell count, might have resulted in toxoplasmosis encephalitis. Rapid and non‐invasive methods such as a polymerase chain reaction (PCR) test of their cerebrospinal fluid for Toxoplasma gondii and magnetic resonance imaging of the brain were useful for providing a definitive diagnosis and prompt therapy in these patients: one patient stabilized and survived after responding to treatment with pyrimethamine/sulfodiazine whereas the other died of bacterial infection. In addition, retrospective PCR analyses of the frozen stored peripheral blood samples disclosed that detection of T. gondii preceded the onset of disease, indicating routine PCR testing of peripheral blood specimens may be an early diagnostic tool. It should be noted that when patients receiving HSCT have an unexplained fever and/or neurological complications, PCR tests should be considered to avoid cerebral lesions and improve the outcome of the patients.

Mobilization of Human Lymphoid Progenitors after Treatment with Granulocyte Colony-Stimulating Factor

Hemopoietic stem and progenitor cells ordinarily residing within bone marrow are released into the circulation following G-CSF administration. Such mobilization has a great clinical impact on hemopoietic stem cell transplantation. Underlying mechanisms are incompletely understood, but may involve G-CSF-induced modulation of chemokines, adhesion molecules, and proteolytic enzymes. We studied G-CSF-induced mobilization of CD34+CD10+CD19−Lin− and CD34+CD10+CD19+Lin− cells (early B and pro-B cells, respectively). These mobilized lymphoid populations could differentiate only into B/NK cells or B cells equivalent to their marrow counterparts. Mobilized lymphoid progenitors expressed lymphoid- but not myeloid-related genes including the G-CSF receptor gene, and displayed the same pattern of Ig rearrangement status as their bone marrow counterparts. Decreased expression of VLA-4 and CXCR-4 on mobilized lymphoid progenitors as well as multipotent and myeloid progenitors indicated lineage-independent involvement of these molecules in G-CSF-induced mobilization. The results suggest that by acting through multiple trans-acting signals, G-CSF can mobilize not only myeloid-committed populations but a variety of resident marrow cell populations including lymphoid progenitors.

Different Risk Factors Related to Adenovirus- or BK Virus-Associated Hemorrhagic Cystitis following Allogeneic Stem Cell Transplantation

Virus-associated hemorrhagic cystitis (HC) is a major cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation (HSCT). Although numerous studies have attempted to identify factors that predispose patients to viral HC, its causes remain controversial. We analyzed retrospectively the results of 266 allogeneic HSCTs to identify factors associated with HC. Of this group, 42 patients (15.8%) were diagnosed with viral HC, because of either adenovirus (ADV; n = 26; 9.8%) or BK virus (BKV; n = 16; 6.0%). ADV-HC was frequently associated with T cell purging, and was less common in patients with acute graft-versus-host-disease (GVHD). Conversely, BKV-HC was more frequently observed in patients with excessive immune reactions such as GVHD, preengraftment immune reaction, and hemophagocytic syndrome. These observations indicate that ADV- and BKV-HC may differ significantly in their risk factors and pathogenesis. Profound immune deficiency is more likely to be associated with ADV-HC, whereas immune hyperactivity might play a key role in BKV-HC.

Successful Treatment of Primary Cardiac Lymphoma by Rituximab-CHOP and High-Dose Chemotherapy with Autologous Peripheral Blood Stem Cell Transplantation

Primary cardiac lymphoma (PCL) is defined as lymphoma involving only the heart and/or pericardium, or with an intraperi-cardial location of the main tumor mass. It is an extremely rare type of lymphoma and has a poor prognosis because of diagnostic delay and the disease site. PCL is histologically characterized by a mostly diffuse large B-cell lymphoma. The median survival time has been reported to be 7 months. We present the case of a 55-year-old woman who presented with chest oppression and dyspnea on effort. Following a close examination, PCL with a high International Prognostic Index was diagnosed. She received 6 courses of R-CHOP therapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) and achieved complete remission. The patient then underwent a consolidation therapy consisting of high-dose chemotherapy including rituximab, followed by autologous peripheral blood stem cell transplantation. There were no complications, such as pulmonary embolism, fatal arrhythmia, or acute heart failure, throughout chemotherapy. Our experience indicates that this therapy is safe and effective and can improve the outcome of high-risk PCL.

High incidence of false-positive Aspergillus galactomannan test in multiple myeloma†

Invasive aspergillosis (IA) remains one of the most significant causes of morbidity and mortality in patients with hematological malignancies undergoing chemotherapy and hematopoietic stem cell transplantation (HSCT), mainly due to the difficulty in its early diagnosis. Monitoring of galactomannan (GM) antigen, an exoantigen of Aspergillus, in the blood by sandwich ELISA is a useful and noninvasive method for early diagnosis of IA. The GM test has a sensitivity of 67-100% with a specificity of 81-99% in neutropenic patients and allogeneic transplant recipients [1-3]. Although it has been widely used as a diagnostic criterion for IA [4,5], one of the major limitations of this assay is false-positivity, particularly in pediatric patients [1], patients with graft-versus-host disease (GVHD) [6,7], and those taking dietary GM [8,9] or fungus-derived antibiotics, such as piperacillin-tazobactam (PIPC/TAZ) [10-12].

Infectious complications in patients receiving autologous CD34-selected hematopoietic stem cell transplantation for severe autoimmune diseases

Abstract: Long‐term analysis of infectious complication after high‐dose immunosuppressive therapy with CD34‐selected autologous hematopoietic stem cell transplantation for patients with severe autoimmune diseases (AD) was performed. Theoretically, CD34 selection can reduce the risk of reinfusion of autoreactive lymphocytes. However, it is also associated with a significant reduction in T cells, natural killer cells, and monocytes, which in turn may compromise immune reconstitution, thereby increasing the risk of infection. Moreover, AD compromises host immunity and causes organ damage resulting in dysfunction of the cutaneous or mucosal barrier. In this study, the incidence rate of infections is reported in 14 patients who underwent high‐dose (200 mg/kg) cyclophosphamide therapy followed by reinfusion of CD34‐selected autologous peripheral blood stem cells. Bacterial complication occurred in 3 of 14 (21%) patients. Cytomegalovirus reactivation and adenovirus hemorrhagic cystitis were observed in 9 (64%) and 2 (14%) patients, respectively. As for late infectious complications, 7 patients (50%) developed dermatomal varicella zoster virus infection. No infection‐related mortality was seen in this case series. Because the risk for infections approaches that seen in allogeneic transplant recipients, infection surveillance, diagnostic workup, and prophylactic strategies similar to those applicable to allogeneic recipients are warranted.