Hematopoietic stem cell transplantation for severe aplastic anemia--experience of an institute in Taiwan

Efficacy and safety of equine anti-thymocyte immunoglobulin (eATG) in three Japanese patients with moderate to very severe aplastic anemia: a case series

Aplastic anemia results from lymphocyte-mediated destruction of hematopoietic stem cells. Immunosuppressive therapy with anti-thymocyte globulin (ATG) and cyclosporine is the standard front-line treatment for patients with severe aplastic anemia who are not suitable candidates for stem cell transplants. PF-06462700 is a potent equine ATG that targets T-lymphocytes and has been approved as a treatment for aplastic anemia outside of Japan for over 30 years. Due to the high medical need for PF-06462700, the Ministry of Health, Labor and Welfare requested its development for Japanese patients with aplastic anemia. In this case series, the efficacy and safety of PF-06462700, administered intravenously at 40 mg/kg/day for 4 days, were assessed over a 24-week period. This was as an open-label, single-arm, multicenter clinical study designed to enroll a minimum of three Japanese participants with aplastic anemia. Two participants met the primary outcome of hematologic response at week 12 and improvements in disease severity were observed. No deaths or serious adverse events were reported. The efficacy results from this case series suggest that administration of PF-06462700 is generally well-tolerated and produces a hematologic response in Japanese patients with aplastic anemia, which should be further evaluated in real-world studies.ClinicalTrials.gov identifier: NCT04350606.

[Outcome analysis of allogeneic hematopoietic stem cell transplantation for 41 patients with severe aplastic anemia]

目的

评价异基因造血干细胞移植（allo-HSCT）治疗重型再生障碍性贫血（SAA）患者的疗效。

方法

回顾性分析2001年10月至2015年5月接受allo-HSCT治疗的41例SAA患者的临床资料。其中男27例，女14例，中位年龄为17(2~43）岁。其中同胞相合移植24例，无关供者移植17例。

结果

38例患者移植后获得造血重建，造血重建率为92.68%。可评估患者的中性粒细胞和血小板的中位植入时间分别为16(10~57) d和20(9~83) d。13例发生急性移植物抗宿主病（aGVHD），8例发生慢性移植物抗宿主病，5例发生移植物排斥反应。中位随访27(3~154）个月，预期3年总生存（OS）率为（75.1±8.3）%。10例患者死亡，移植相关死亡率为24.39%。多因素分析结果显示：移植后发生Ⅱ~Ⅳ度aGVHD[P=0.018，OR=27.481(95% CI 2.377~392.636）]和侵袭性真菌病[P=0.021，OR=21.364(95% CI 1.732~354.185）]为影响SAA患者allo-HSCT后OS的独立危险因素。

结论

同胞相合供者和HLA匹配的无关供者allo-HSCT是治疗SAA患者的有效手段，Ⅱ~Ⅳ度aGVHD和侵袭性真菌病与移植后OS率较低有关。

Use of azathioprine for graft-vs-host disease is the major risk for development of secondary malignancies after haematopoietic stem cell transplantation: a nationwide population-based study

BACKGROUND

As more patients are treated by haematopoietic stem cell transplantation (HSCT), development of secondary malignancy (SM) becomes an increasingly common issue in long-term survivors.

METHODS

We conducted a nationwide population-based study of the Taiwanese population to analyse patients who received HSCT between January 1997 and December 2010. Standardised incidence ratios (SIRs) were used to compare the risk of SM in HSCT patients and the general population. Multivariate analysis was performed to identify independent predictors of SM.

RESULTS

Patients receiving HSCT had a significantly greater risk of developing SM (SIR 2.00; 95% confidence interval (CI) 1.45-2.69; P<0.001). Specifically, the incidence increased for cancers of the oral cavity (SIR 14.18) and oesophagus (SIR 14.75) after allogeneic HSCT. Multivariate analysis revealed an increased SIR for cancer in patients who received the immunosuppressant azathioprine. The risk of SM also increased with greater cumulative doses of azathioprine.

CONCLUSIONS

This study demonstrates an increased incidence of SM in Taiwanese patients who received allogeneic HSCT, especially for cancers of the oral cavity and oesophagus. This finding is different from results in populations of Western countries. Physicians should be cautious about azathioprine use for graft-vs-host disease after HSCT.

Hemorrhagic cystitis in children treated with alkylating agent cyclophosphamide: The experience of a medical center in Taiwan

BACKGROUND/PURPOSE

Hemorrhagic cystitis is a common complication with chemotherapeutic alkylating agents. We investigated the possible prognostic factors of cyclophosphamide-induced hemorrhagic cystitis in children.

METHODS

Medical records of children (< 18 years old) with cyclophosphamide-related hemorrhagic cystitis were collected retrospectively from January 2000 to December 2010 in a tertiary care center. We also prospectively enrolled children (< 18 years old) with cyclophosphamide treatment.

RESULTS

The retrospective study consisted of 23 patients whose median age was 11 years. The median day of onset time was 1 day after cyclophosphamide usage. The hemato-oncological diseases included acute leukemia (39.1%), lymphoma (13%), blastoma (13%), sarcoma (13%), aplastic anemia (13%), and others (8.7%). Patients who received bone marrow transplantation (BMT) had significantly longer duration of hemorrhagic cystitis than those who did not receive BMT (p < 0.05). Serum uric acid, checked prior to and after the onset of hemorrhage cystitis, was significantly lower after the development of hemorrhagic cystitis (p < 0.05). In the prospective study, 11 children were enrolled with a median age of 5 years. The urinary nitrite/nitrate and 8-iso-prostaglandin F2α levels increased significantly after cyclophosphamide usage (p < 0.05).

CONCLUSION

Alteration serum uric acid level and BMT could be indicators for severe hemorrhagic cystitis. The elevated levels of urinary nitrite/nitrate and 8-iso-prostaglandin F2α may indicate the essential roles played by nitric oxide syntheses and reactive oxidative stress in cyclophosphamide-induced hemorrhagic cystitis. These findings may help clinicians formulate a better strategy for treating cyclophosphamide-induced hemorrhagic cystitis.

Reprogrammed cells for disease modeling and regenerative medicine

The conversion of somatic cells into pluripotent cells is transforming the way diseases are researched and treated. Induced pluripotent stem (iPS) cells' promise may soon be realized in the field of hematology, as hematopoietic stem cell transplants are already commonplace in clinics around the world. We provide a current comparison between induced pluripotent and embryonic stem cells, describe progress toward modeling hematological disorders using iPS cells, and illustrate the hurdles that must be overcome before iPS cell therapies will be available in clinics.

Impact of bloodstream infections on outcome and the influence of prophylactic oral antibiotic regimens in allogeneic hematopoietic SCT recipients

This study aimed to determine the impact of blood stream infections (BSIs) on outcome of allogeneic hematopoietic SCT (HSCT), and to examine the influence of old (non-levofloxacin-containing) and new (levofloxacin-based) prophylactic antibiotic protocols on the pattern of BSIs. We retrospectively enrolled 246 allogeneic HSCT recipients between January 1999 and June 2006, dividing patients into BSI (within 6 months post-HSCT, n=61) and non-BSI groups (n=185). We found that Gram-negative bacteria (GNB) predominated BSI pathogens (54%). Multivariate analyses showed that patients with a BSI, compared with those without, had a significantly greater 6-month mortality (hazard ratio, 1.75; 95% confidence interval, 1.09-2.82; P=0.021) and a significantly increased length of hospital (LOH) stay (70.8 vs 55.2 days, P=0.014). Moreover, recipients of old and new protocols did not have a significantly different 6-month mortality and time-to-occurrence of BSIs. However, there were significantly more resistant GNB to third-generation cephalosporins and carbapenem in recipients of levofloxacin-based prophylaxis. Our data suggest that BSIs occur substantially and impact negatively on the outcome and LOH stay after allogeneic HSCT despite antibiotic prophylaxis. Levofloxacin-based prophylaxis, albeit providing similar efficacy to non-levofloxacin-containing regimens, may be associated with increased antimicrobial resistance.

Current status of hematopoietic stem cell transplantation in Taiwan

In Taiwan, hematopoietic SCT (HSCT) has been used to treat patients with hematological diseases since 1983. Since then, more than 2200 patients have undergone HSCT in 15 large hospitals. The disease entities included acute leukemia in 37% of cases, non-Hodgkin's lymphoma in 26%, CML in 10%, multiple myeloma in 7% and severe aplastic anemia in 6%. The conditioning regimens used were mainly myeloablative (84% of cases). Non-myeloablative regimens were fludarabine-based. The average age of allogeneic recipients was at least 10 years older than those in the era before their application. The grafts of all patients were derived from peripheral blood in 85% of cases, BM in 13% and cord blood (CB) in 2%. Forty percent of HSCT patients received autologous grafts, whereas more than 25% of allogeneic HSCT patients received grafts from unrelated donors, and overall, there were more than 200 Taiwan HSCT recipients. Currently, CB has been used successfully in pediatric patients with thalassemia major and also in adult patients with hematological malignancy. After transplantation, there was a relatively lower prevalence of acute GVHD. However, a relatively higher proportion of hepatitis B carriers in the recipients had led to a higher incidence of viral reactivation and clinical hepatitis, which was dramatically decreased following lamivudine prophylaxis. In conclusion, HSCT has been successfully adapted to routine clinical care in Taiwan. Several important findings contributing to the progress of HSCT in the past two decades have also been noticed on this island.

Rituximab therapy increased post-transplant cytomegalovirus complications in Non-Hodgkin's lymphoma patients receiving autologous hematopoietic stem cell transplantation

The use of monoclonal antibody, rituximab, had been reported to be associated with some severe viral infections. The inference of rituximab therapy and post-transplant cytomegalovirus (CMV) infectious complications in non-Hodgkin's lymphoma (NHL) patients is still unclear now. From 2002 to 2005, 46 patients with relapsed indolent or high-risk aggressive B cell NHL who received rituximab (17 patients) or not (29 patients) before autologous hematological stem cell transplantation (HSCT) in one institute were retrospectively analyzed for the risk factors of CMV complications after transplantation. Pre-transplant and post-transplant CMV infectious conditions, conditioning regimens, transplant types, and post-transplant complications were recorded. Post-transplant infectious complications were followed up until 6 months after transplantation. Seventeen of 46 patients received rituximab before HSCT. Three of them suffered from CMV infection and two of them developed CMV disease. All of the patients with CMV disease recovered after ganciclovir and CMV-specific immunoglobulin therapy. Twenty-nine of 46 patients without rituximab treatment before HSCT did not have CMV complications after HSCT. The risks to develop CMV infections after autologous HSCT were higher in rituximab-treated patients (17.6% vs 0%, p = 0.045, Fisher exact test, two-sided). The risks to develop CMV diseases had higher trend with rituximab therapy than without rituximab therapy (11.7% vs 0%, p = 0.131, Fisher exact test, two-sided). The NHL patients receiving rituximab therapy had higher risk to develop CMV infectious complications after autologous HSCT.

Current concepts in the pathophysiology and treatment of aplastic anemia

Aplastic anemia, an unusual hematologic disease, is the paradigm of the human bone marrow failure syndromes. Almost universally fatal just a few decades ago, aplastic anemia can now be cured or ameliorated by stem-cell transplantation or immunosuppressive drug therapy. The pathophysiology is immune mediated in most cases, with activated type 1 cytotoxic T cells implicated. The molecular basis of the aberrant immune response and deficiencies in hematopoietic cells is now being defined genetically; examples are telomere repair gene mutations in the target cells and dysregulated T-cell activation pathways. Immunosuppression with antithymocyte globulins and cyclosporine is effective at restoring blood-cell production in the majority of patients, but relapse and especially evolution of clonal hematologic diseases remain problematic. Allogeneic stem-cell transplant from histocompatible sibling donors is curative in the great majority of young patients with severe aplastic anemia; the major challenges are extending the benefits of transplantation to patients who are older or who lack family donors. Recent results with alternative sources of stem cells and a variety of conditioning regimens to achieve their engraftment have been promising, with survival in small pediatric case series rivaling conventional transplantation results.

The influence of the conditions of hematopoietic cell transplantation on infectious complications

PURPOSE OF REVIEW

The multitude of factors that influence the risk of infection after hematopoietic cell transplantation has been further complicated by the rapid evolution of this therapy in the past 5 years. The degree to which functional immune reconstitution has been achieved reflects the equilibrium reached by the immune systems of the recipient and donor in the context of host non-hematopoietic tissue. Thus immunomodulatory influences on the recipient and the transplanted graft, both before and after hematopoietic cell transplantation, have a profound influence on the incidence and severity of infection. This review of the recent literature contributes to our understanding of how the conditions of hematopoietic cell transplantation influence the timing and nature of infectious complications.

RECENT FINDINGS

The main themes of published primary research from 2004 to the present focus on non-myeloablative conditioning regimens and their effects on immune reconstitution after hematopoietic cell transplantation.

SUMMARY

A plethora of clinical trials are ongoing, focused on the outcome after conditioning regimens designed to result in less regimen-related toxicity while preserving or enhancing the graft-versus-tumor effect. Given the infancy of these new approaches, it is not possible to make definitive statements regarding the relative risk of serious infection with each therapy. It is clear that a reduction in regimen-related non-infectious complications or mortality does not necessarily ensure a reduction in clinically significant infections. Improvements in early diagnostic and therapeutic options for these infections now bring us to an era of understanding pathogens as probes of the functional reconstitution of immunity.

Favorable effect on acute and chronic graft-versus-host disease with cyclophosphamide and in vivo anti-CD52 monoclonal antibodies for marrow transplantation from HLA-identical sibling donors for acquired aplastic anemia

Between August 1989 and November 2003, 33 patients at our center with acquired aplastic anemia underwent bone marrow transplantation (BMT) from HLA-identical sibling donors with cyclophosphamide and in vivo anti-CD52 monoclonal antibodies (MoAb) for conditioning. The median age at BMT was 17 years (range, 4-46 years). Before BMT, 58% were heavily transfused (>50 transfusions), and 42% had previously experienced treatment failure with antithymocyte globulin-based immunosuppressive therapy. Unmanipulated bone marrow was used as the source of stem cells in all patients except 1. Graft-versus-host disease (GVHD) prophylaxis was with cyclosporine alone in 19 (58%) patients; 14 received anti-CD52 MoAb in addition to cyclosporine. The conditioning regimen was well tolerated without significant acute toxicity. Graft failure was seen in 8 patients (primary, n = 4; secondary, n = 4). Of those whose grafts failed, 4 survived long-term (complete autologous recovery, n = 2; rescue with previously stored marrow, n = 1; second allograft, n = 1). The cumulative incidence of graft failure and grade II to IV acute and chronic GVHD was 24%, 14%, and 4%, respectively. None developed extensive chronic GVHD. With a median follow-up of 59 months, the 5-year survival was 81% (95% confidence interval, 68%-96%). No unexpected early or late infectious or noninfectious complications were observed. We conclude that the conditioning regimen containing cyclophosphamide and anti-CD52 MoAb is well tolerated and effective for acquired aplastic anemia with HLA-matched sibling donors. The favorable effect on the incidence and severity of GVHD is noteworthy in this study and warrants further investigation.