Yu Akahoshi

Antibiotic prophylaxis in hematopoietic stem cell transplantation. A meta-analysis of randomized controlled trials.

OBJECTIVES We performed a meta-analysis to evaluate the impact of systemic antibiotic prophylaxis in hematopoietic stem cell transplantation (HSCT) recipients. METHODS We collected reports from PubMed, the Cochrane Library, EMBASE, CINAHL, and Web of Science, along with references cited therein. We included prospective, randomized studies on systemic antibiotic prophylaxis in HSCT recipients. RESULTS Seventeen trials with 1453 autologous and allogeneic HSCT recipients were included. Systemic antibiotic prophylaxis was compared with placebo or no prophylaxis in 10 trials and with non-absorbable antibiotics in two trials. Systemic antibiotics other than fluoroquinolones were evaluated in five of these 12 trials. Four trials evaluated the effect of the addition of antibiotics for gram-positive bacteria to fluoroquinolones. One trial compared two different systemic antibiotic regimens: fluoroquinolones versus trimethoprim-sulfamethoxazole. As a result, systemic antibiotic prophylaxis reduced the incidence of febrile episodes (OR 0.16; 95%CI 0.09-0.30), clinically or microbiologically documented infection (OR 0.38; 95%CI 0.22-0.63) and bacteremia (OR 0.31; 95%CI 0.16-0.59) without significantly affecting all-cause mortality or infection-related mortality. CONCLUSIONS Systemic antibiotic prophylaxis successfully reduced the incidence of infection. However, there was no significant impact on mortality. The clinical benefits of prophylaxis with fluoroquinolones were inconclusive because of the small number of clinical trials evaluated.

Risk factors for pre‐ and post‐engraftment bloodstream infections after allogeneic hematopoietic stem cell transplantation

Bloodstream infections (BSI) are frequently observed after allogeneic hematopoietic stem cell transplant (HSCT), and could cause morbidity and mortality.

High Incidence of Afebrile Bloodstream Infection Detected by Surveillance Blood Culture in Patients on Corticosteroid Therapy after Allogeneic Hematopoietic Stem Cell Transplantation.

Bloodstream infections (BSI) are still important complications after allogeneic hematopoietic stem cell transplantation (allo-SCT). Patients who are receiving corticosteroid therapy can develop BSI without fever. The utility of surveillance blood cultures in these situations is controversial. We retrospectively analyzed 74 patients who received a corticosteroid consisting of ≥.5 mg/kg prednisolone or equivalent after allo-SCT. In principle, we performed surveillance blood culture weekly for these patients. Sixteen patients (21.6%) developed definite BSI. In a multivariate analysis, a myeloablative conditioning regimen, high-risk disease status at allo-SCT, and the presence of a central venous catheter at the initiation of corticosteroid therapy were identified as independent significant risk factors for the development of definite BSI. At the first definite BSI episode, 7 patients (46.7%) were afebrile and diagnosed by surveillance blood culture. However, 6 of these 7 afebrile patients showed various signs that could be attributed to infection at the time of positive blood culture. In conclusion, patients receiving corticosteroid therapy after allo-SCT frequently develop afebrile BSI. Although surveillance blood culture might be beneficial in these situations, it also seems important to not miss the signs of BSI, even when patients are afebrile.

Reduced-dose (two-thirds) R-CHOP chemotherapy for elderly patients with non-Hodgkin lymphoma.

Abstract Elderly patients with non-Hodgkin lymphoma (NHL) have a poor prognosis. Owing to treatment-related toxicities, there is no standard chemotherapy for the elderly patients, especially those aged 70 years or older. In this study, we retrospectively evaluated the efficacy and toxicity of reduced-dose (two-thirds) R-CHOP chemotherapy as an initial chemotherapy for 45 patients aged 70 years or older with B-cell NHL. The WHO classification of NHL included diffuse large B-cell lymphoma (DLBCL) (31), mantle cell lymphoma (5), follicular lymphoma (4), extranodal marginal zone lymphoma (1), Burkitt lymphoma (1), and B-cell lymphoma whose further types were unclassified (3). The incidences of grade 4 neutropenia and febrile neutropenia (FN) were 51·1 and 15·6%, respectively. Efficacy was evaluated in patients with DLBCL. The overall and complete response (CR) rates were 96·7 and 90·0%, respectively. Two-year event-free survival (EFS) and overall survival (OS) were 84·4 and 89·2%, respectively. There was no treatment-related mortality. In conclusion, two-thirds R-CHOP chemotherapy is a promising treatment for elderly patients with B-cell NHL in terms of its efficacy and toxicity.

Significance of a positive Clostridium difficile toxin test after hematopoietic stem cell transplantation

Patients with hematological malignancies show a high prevalence of asymptomatic colonization with Clostridium difficile (CD colonization). Therefore, it is difficult to distinguish CD colonization with diarrhea induced by a conditioning regimen from true Clostridium difficile infection (CDI) in hematopoietic stem cell transplantation (HSCT) recipients. We retrospectively analyzed 308 consecutive patients who underwent a CD toxin A/B enzyme immunoassay test for diarrhea within 100 d after HSCT from November 2007 to May 2014. Thirty patients (9.7%) had positive CD toxin results, and 11 of these had positive results in subsequent tests after an initial negative result. Allogeneic HSCT, total body irradiation, stem cell source, acute leukemia, and the duration of neutropenia were significantly correlated with positive CD toxin results. In a logistic regression model, allogeneic HSCT was identified as a significant risk factor (odds ratio 18.6, p < 0.01). In an analysis limited to within 30 d after the conditioning regimen, the duration of neutropenia was the sole risk factor (odds ratio 10.4, p < 0.01). There were no distinctive clinical features for CDI, including the onset or duration of diarrhea. In conclusion, although CDI may be overdiagnosed in HSCT recipients, it is difficult to clinically distinguish between CDI and CD colonization.

A retrospective analysis of computed tomography findings in patients with pulmonary complications after allogeneic hematopoietic stem cell transplantation

OBJECTIVE The purpose of this study was to review the high-resolution computed tomography (CT) findings in patients with pulmonary complications after allogeneic hematopoietic stem cell transplantation (HSCT), and to evaluate the relationship between CT findings and clinical outcomes. PATIENTS AND METHODS We collected the clinical data in 96 consecutive patients who underwent CT scan for pulmonary complications after allogeneic HSCT and analyzed the relationships among these clinical characteristics, CT findings and clinical responses. Radiologists who were blinded to clinical information evaluated the CT findings. RESULTS In multivariate analyses, the presence of chronic graft-versus-host disease (GVHD) and non-segmental multiple consolidations were significantly associated with a poor response to antimicrobial therapies, and the disease risk was significantly associated with a poor corticosteroid response. In addition, the existence of cavity formation and pleural effusion were significantly associated with a fatal prognosis. Twenty-five patients underwent bronchoscopic examination and 4 of them also underwent transbronchial lung biopsy (TBLB), but diagnostic information was not obtained in 15 patients. There was no significant association between specific CT findings and the diagnosis based on bronchoscopic examination. CONCLUSIONS No specific CT finding was identified as a predictor for either an antimicrobial response or for a corticosteroid response in this study. The presence of cavity formation and pleural effusion may predict a poor prognosis.

Prediction of infectious complications by the combination of plasma procalcitonin level and localized infection before allogeneic hematopoietic cell transplantation.

We previously reported that the baseline C-reactive protein level did not predict infectious events after hematopoietic cell transplantation (HCT). Procalcitonin (PCT) has recently emerged as a powerful biomarker for the early diagnosis of bacterial infection. We evaluated the ability of the baseline PCT level to predict early infectious events after HCT in 79 recipients who received HCT between 2008 and 2012. The high-PCT group (⩾0.07 ng/mL, n=27) frequently experienced documented infection (DI) (21.2% vs 44.4% at day 30, P=0.038) and bloodstream infection (BSI) (15.4% vs 37.0% at day 30, P=0.035). In a multivariate analysis, however, the baseline PCT level was not significantly associated with DI (HR 2.01, P=0.089) or BSI (HR 2.28, P=0.084). Localized infection, such as anal canal problems, before the start of conditioning was seen in 26 patients. When we stratified the patients according to the presence of elevated PCT and localized infection, the group with elevated PCT and localized infection (n=17) was significantly associated with increased DI (HR 3.40, P=0.0074) and BSI (HR 3.59 P=0.0078) after HCT. A larger prospective observation is warranted to confirm the impact of the baseline PCT level and clinical features on the outcome of HCT.

Universal cytotoxic activity of a HTLV-1 Tax-specific T cell clone from an HLA-A*24:02+ patient with adult T-cell leukemia against a variety of HTLV-I-infected T-cells

Adult T cell leukemia/lymphoma (ATL) is an aggressive mature T cell malignancy that is causally associated with human T cell lymphotropic virus type 1 (HTLV-1) infection. The HTLV-1 regulatory protein Tax aggressively accelerates the proliferation of host cells and is also an important target antigen for CD8(+) cytotoxic T cells (CTLs). We previously reported that several predominant HLA-A*24:02-restricted HTLV-1 Tax301-309-specific CTL clones commonly expressed a particular amino acid sequence motif (P-D-R) in complementarity-determining region 3 of T-cell receptor (TCR)-β chain among unrelated ATL patients who underwent allogeneic stem cell transplantation (allo-HSCT). Furthermore, a PDR-motif(+) CTL clone persistently existed in a long-term survivor as a central CTL clone with strong CTL activities after HSCT. Although a larger analysis of the relationship between PDR-motif(+) CTLs and the clinical course is required, the expression of PDR-motif(+) TCR on CD8(+) T cells may play a critical role in the management of anti-HTLV-1 activities for HLA-A24:02(+) ATL patients. Therefore, in this study, we prepared an HTLV-1 Tax301-309 peptide-specific CTL clone (HT-9) expressing PDR-motif(+) TCR isolated from a long-term survivor after HSCT, and evaluated its CTL activity against a variety of HTLV-1-infected T-cells from HLA-A*24:02(+) ATL patients. Before the assay of CTL function, we confirmed that HT-9 expressed less-differentiated effector-memory phenotypes (CD45RA(-)CCR7(-)CD27(+)CD28(+/-)CD57(+/-)) and T-cell exhaustion marker PD-1(+). In assays of CTL function, HT-9 recognized HTLV-1 Tax in an HLA-restricted fashion and demonstrated strong CTL activities against a variety of HTLV-1-infected T-cells from HLA-A*24:02(+) ATL patients regardless of whether the sources were autologous or allogeneic, but not normal cells. These data indicate that PDR-motif(+) TCR could be an important TCR candidate for TCR-gene immunotherapy for HLA-A24:02(+) ATL patients, provided that the CTL activities against HTLV-1 are reproduced in in vivo experiments using mouse models.

Risk Factors and Impact of Secondary Failure of Platelet Recovery After Allogeneic Stem Cell Transplantation.

Secondary failure of platelet recovery (SFPR), a late decrease in the platelet count after primary platelet recovery that is not due to relapse or graft rejection, occasionally occurs after allogeneic hematopoietic stem cell transplantation (HSCT). The risk factors and impact of SFPR on transplantation outcomes are not well known in the clinical setting. Therefore, we retrospectively evaluated 184 adult patients who underwent their first allogeneic HSCT and achieved primary platelet recovery. The cumulative incidence of SFPR, defined as a decrease in the platelet count to below 20,000/µL for more than 7 days, was 12.2% at 3 years, with a median onset of 81 days (range, 39 to 729) after HSCT. Among patients who developed SFPR (n = 23), 19 (82.6%) showed recovery to a sustained platelet count of more than 20,000/µL without transfusion support, and the median duration of SFPR was 23 days (range, 7 to 1048 days). A multivariate analysis showed that in vivo T cell depletion (hazard ratio [HR], 6.92; 95% confidence interval [CI], 2.31 to 20.7; P < .001), grades II to IV acute graft-versus-host disease (HR, 3.99; 95% CI, 1.52 to 10.5; P = .005), and the use of ganciclovir or valganciclovir (HR, 2.86; 95% CI, 1.05 to 7.77; P = .039) were associated with an increased risk for SFPR. The occurrence of SFPR as a time-dependent covariate was significantly associated with inferior overall survival (HR, 2.29; 95% CI, 1.18 to 4.46; P = .015) in a multivariate analysis. These findings may help to improve the management and treatment strategy for SFPR.

Evaluation of the immune status against measles, mumps, and rubella in adult allogeneic hematopoietic stem cell transplantation recipients

Abstract Background Previous studies have shown that most patients lose immunity to measles, mumps, and rubella (MMR) during long-term follow-up after allogeneic hematopoietic stem cell transplantation (HSCT), and immunizations against them have been investigated. However, these previous studies mainly targeted pediatric patients and information in adult patients is still insufficient. Methods We evaluated the immunity to MMR in 45 adult allogeneic HSCT patients. None of these patients received vaccination after HSCT. Results The seropositive rates at six years after allogeneic HSCT were estimated to be less than 44% for measles, less than 10% for mumps, and less than 36% for rubella. Thirteen of the 16 female patients who were 16–39 years old were negative or equivocal for rubella. Patients who developed grade II–IV acute graft-versus-host disease tended to become seronegative for measles and rubella at two years after HSCT, although the difference was not statistically significant. Conclusions This study showed that most adult patients lost immunity to MMR after allogeneic HSCT. Although we did not evaluate the safety and efficacy of vaccination in this study, most HSCT guidelines recommend vaccination for HSCT recipients without active chronic graft-versus-host disease or ongoing immunosuppressive therapy at 24 months after HSCT. Immunization against rubella is especially important for female patients of reproductive age. Further studies will be necessary to evaluate the effect of vaccination on the antibody response in adult allogeneic HSCT recipients.