Kiriko Terasako-Saito

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.

Evaluation of the validity of preemptive therapy against cytomegalovirus disease based on antigenemia assay with a cutoff of 20 positive cells per two slides.

Background Preemptive therapy with ganciclovir (GCV) based on the results of a cytomegalovirus (CMV) antigenemia assay is a standard strategy for preventing CMV disease after allogeneic hematopoietic cell transplantation (HCT). However, the appropriate threshold of antigenemia-positive cells for deciding when to start GCV remains unclear. Patients This retrospective study included 80 recipients who received HCT from an alternative donor between 2007 and 2011. In 2009, we switched the threshold from 3 (3A group, n=24) to 20 (20A group, n=56) antigenemia-positive cells per two slides for preemptive therapy after HCT from an alternative donor. Results Early CMV disease within 100 days after HCT was observed in one patient in the 20A group. Antiviral agents including GCV, val-GCV, and foscarnet were given in 17 (71%) and 36 (64%) patients in the 3A and 20A groups, respectively (p=0.23). In 13 (23%) patients in the 20A group, the initiation of preemptive therapy was avoided because of the change in the cutoff value for CMV antigenemia. However, the total dose of GCV was not different between the two groups. The use of steroid was significantly associated with CMV antigenemia of at least 20 positive cells among patients with low-level antigenemia at the first detection. Conclusion The increased threshold up to 20 positive cells for starting preemptive therapy was not associated with a significant increase in CMV disease, but the total dose of GCV was not reduced and there was one early CMV disease in the 20A group. We should explore how to identify patients who are at high risk for increased antigenemia among patients with low-level antigenemia, but at least, preemptive therapy should not be withheld in patients who are already receiving systemic steroid.

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.

Impact of high-/middle-molecular-weight adiponectin on the synthesis and regulation of extracellular matrix in dermal fibroblasts.

Adiponectin has been shown to play a critical role in immunity. Recently, we reported that the adiponectin levels after allogeneic stem cell transplantation were higher in recipients with chronic graft-versus-host disease (cGVHD). However, the effects of adiponectin on extracellular matrix (ECM) and regulatory factors in dermal fibroblasts remain unclear. We compared the messenger RNA (mRNA) levels of collagen type1 (COL1A), fibronectin 1 (FN1), matrix metalloproteinase (MMP)1, MMP3, tissue inhibitor of metalloproteinase (TIMP)1, TIMP3, transforming growth factor-β (TGF-β), and TGF-β receptor 2 (TGF-βR2) in human normal dermal fibroblasts cultured with and without adiponectin, and we assessed the degree of synthesis of ECMs by immunofluorescent microscopy. Furthermore, we also assessed these mRNA levels after blocking of TGF-βR2. Adiponectin induced higher mRNA levels of FN1, MMP1, MMP3, TIMP1, TIMP3, and TGF-βR2 in a dose-dependent manner, but did not significantly affect COL1A or TGF-β. In addition, adiponectin was shown to upregulate FN1, MMPs, and TIMPs after blocking of TGF-βR2. Immunofluorescent microscopy revealed that adiponectin promoted a greater synthesis of ECMs than in the control in vitro. The finding that adiponectin upregulated ECM-associated factors might mean that high levels of adiponectin could modulate dermal fibrosis was observed in recipients with cGVHD. Further basic investigation is warranted to elucidate whether the adiponectin-pathway could be a target for the treatment of sclerotic cGVHD.

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.

Severe oral infection due to Lactobacillus rhamnosus during induction chemotherapy for acute myeloid leukemia

We report a case of severe oral infection with a high fever due to Lactobacillus rhamnosus during induction chemotherapy for acute myeloid leukemia. The patient did not improve on treatment with meropenem, clindamycin, or vancomycin until neutrophil recovery. Since L. rhamnosus GG is used in dairy products, and the patient ingested dairy products daily before starting chemotherapy, we suspected an association between the ingestion of dairy products and the development of infection. Pulsed-field gel electrophoresis using two different restriction enzymes showed that the strain isolated from the patient was identical to the L. rhamnosus GG strain isolated from dairy products and ATCC #53103. This was confirmed by a PCR assay with species-specific L. rhamnosus GG primers. Since Lactobacillus infection, particularly L. rhamnosus infection, can be fatal in immunocompromised hosts, we should consider Lactobacillus as a causative organism when Gram-positive rods are detected during treatment with broad-spectrum antibiotics and vancomycin. The causal association between the ingestion of dairy products containing Lactobacillus and Lactobacillus infection in immunocompromised hosts warrants further study.