Prevention of nosocomial infections in marrow transplant patients: a prospective randomized comparison of systemic antibiotics versus granulocyte transfusions

Gut Microbiota Influence in Hematological Malignancies: From Genesis to Cure

Hematological malignancies, including multiple myeloma, lymphoma, and leukemia, are a heterogeneous group of neoplasms that affect the blood, bone marrow, and lymph nodes. They originate from uncontrolled growth of hematopoietic and lymphoid cells from different stages in their maturation/differentiation and account for 6.5% of all cancers around the world. During the last decade, it has been proven that the gut microbiota, more specifically the gastrointestinal commensal bacteria, is implicated in the genesis and progression of many diseases. The immune-modulating effects of the human microbiota extend well beyond the gut, mostly through the small molecules they produce. This review aims to summarize the current knowledge of the role of the microbiota in modulating the immune system, its role in hematological malignancies, and its influence on different therapies for these diseases, including autologous and allogeneic stem cell transplantation, chemotherapy, and chimeric antigen receptor T cells.

In canine bacterial pneumonia circulating granulocyte counts determine outcome from donor cells

BACKGROUND

In experimental canine septic shock, depressed circulating granulocyte counts were associated with a poor outcome and increasing counts with prophylactic granulocyte colony-stimulating factor (G-CSF) improved outcome. Therapeutic G-CSF, in contrast, did not improve circulating counts or outcome, and therefore investigation was undertaken to determine whether transfusing granulocytes therapeutically would improve outcome.

STUDY DESIGN AND METHODS

Twenty-eight purpose-bred beagles underwent an intrabronchial Staphylococcus aureus challenge and 4 hours later were randomly assigned to granulocyte (40-100 × 109 cells) or plasma transfusion.

RESULTS

Granulocyte transfusion significantly expanded the low circulating counts for hours compared to septic controls but was not associated with significant mortality benefit (1/14, 7% vs. 2/14, 14%, respectively; p = 0.29). Septic animals with higher granulocyte count at 4 hours (median [interquartile range] of 3.81 3.39-5.05] vs. 1.77 [1.25-2.50]) had significantly increased survival independent of whether they were transfused with granulocytes. In a subgroup analysis, animals with higher circulating granulocyte counts receiving donor granulocytes had worsened lung injury compared to septic controls. Conversely, donor granulocytes decreased lung injury in septic animals with lower counts.

CONCLUSION

During bacterial pneumonia, circulating counts predict the outcome of transfusing granulocytes. With low but normal counts, transfusing granulocytes does not improve survival and injures the lung, whereas for animals with very low counts, but not absolute neutropenia, granulocyte transfusion improves lung function.

Efficacy of antibiotic prophylaxis in patients with cancer and hematopoietic stem cell transplantation recipients: A systematic review of randomized trials

PURPOSE

To determine the efficacy and safety of different prophylactic systemic antibiotics in adult and pediatric patients receiving chemotherapy or undergoing hematopoietic stem cell transplantation (HSCT).

METHODS

We conducted a systematic review and performed searches of Ovid MEDLINE, MEDLINE in-process and Embase; and Cochrane Central Register of Controlled Trials. Studies were included if patients had cancer or were HSCT recipients with anticipated neutropenia, and the intervention was systemic antibacterial prophylaxis. Strategies synthesized included fluoroquinolone vs no antibiotic/nonabsorbable antibiotic; fluoroquinolone vs trimethoprim-sulfamethoxazole; trimethoprim-sulfamethoxazole vs no antibiotic; and cephalosporin vs. no antibiotic. Fluoroquinolone vs cephalosporin and levofloxacin vs ciprofloxacin were compared by network meta-analysis. Primary outcome was bacteremia.

RESULTS

Of 20 984 citations screened, 113 studies comparing prophylactic antibiotic to control were included. The following were effective in reducing bacteremia: fluoroquinolone vs no antibiotic/nonabsorbable antibiotic (risk ratio (RR) 0.56, 95% confidence interval (CI) 0.41-0.76), trimethoprim-sulfamethoxazole vs no antibiotic (RR 0.59, 95% CI 0.41-0.85) and cephalosporin vs no antibiotic (RR 0.30, 95% CI 0.16-0.58). Fluoroquinolone was not significantly associated with increased Clostridium difficile infection (RR 0.62, 95% CI 0.31-1.24) or invasive fungal disease (RR 1.28, 95% CI 0.79-2.08) but did increase resistance to fluoroquinolone among bacteremia isolates (RR 3.35, 95% CI 1.12 to 10.03). Heterogeneity in fluoroquinolone effect on bacteremia was not explained by evaluated study, population, or methodological factors. Network meta-analysis revealed no direct comparisons for pre-specified analyses; superior regimens were not identified.

CONCLUSIONS

Fluoroquinolone, trimethoprim-sulfamethoxazole, and cephalosporin prophylaxis reduced bacteremia. A clinical practice guideline to facilitate prophylactic antibiotic decision-making is required.

Fecal Microbiota Transplantation for Treatment of Acute Graft-versus-Host Disease

The growing understanding of the bidirectional relationship between the gastrointestinal (GI) microbiome and the immune system has opened up new avenues for treatment of graft-versus-host disease (GVHD). Fecal microbiota transplantation (FMT) is the transfer of stool from a donor to a recipient who harbors a perturbed GI microbiome resulting in disease. We review the rationale for performing FMT for the treatment of acute GVHD, and summarize data on the safety and efficacy of the procedure among allogeneic hematopoietic stem cell transplantation (HSCT) recipients. Overall, FMT is a promising strategy in treating and preventing HSCT-related complications. However, caution should be exerted as HSCT recipients are highly immunosuppressed and unanticipated infectious adverse events may appear with the increasing application of FMT.

Intestinal Microbiota Influence Immune Tolerance Post Allogeneic Hematopoietic Cell Transplantation and Intestinal GVHD

Under normal conditions our intestines are inhabited by trillions of diverse microorganisms composing the intestinal microbiota, which are mostly non-pathogenic anaerobic commensal bacteria vital for the maintenance of immune homeostasis. The composition and diversity of the intestinal microbiota can be disturbed by various factors including diet, antibiotics, and exposure to intestinal pathogens. Alterations of the intestinal microbiota contributes to many diseases including graft-vs.-host disease (GVHD), a life threatening complication that occurs after allogeneic hematopoietic cell transplantation (allo-HCT) caused by an allogeneic reaction of donor T cells against recipient target tissues. Intestinal GVHD is most difficult to treat and connected to a high mortality. Due to recent advances in high-throughput sequencing technology, composition of the microbiome during allo-HCT has been characterized, and some common patterns have been identified. Metabolites produced by intestinal bacteria were shown to promote intestinal tissue homeostasis and immune tolerance post-allo-HCT. In this review, we discuss the role of the intestinal microbiota and metabolites in the context of acute GVHD. Moreover, novel therapeutic approaches that aim at protecting or regenerating intestinal cell populations will be highlighted.

Granulocyte transfusions: A concise review for practitioners

Granulocyte transfusions (GTXs) have been used to treat and prevent infections in neutropenic patients for more than 40 years, despite persistent controversy regarding their efficacy. This narrative review attempts to complement recent systematic reviews by the Cochrane Collaboration and provide both historical context and critical assessment of the most significant clinical studies published over the years. The data suggest that properly collected and promptly infused granulocytes are active against infections, both bacterial and fungal. The most important question that remains unanswered is in which patients the administration of granulocytes will be beneficial. The preponderance of evidence suggests that granulocyte transfusions may be efficacious in few select cases as a temporizing measure to control an infection that is expected (or proven) to be refractory to optimal antimicrobial treatment, and that could otherwise be controlled by marrow recovery, which is expected to happen. In this regard, they are best considered a "bridge" that grants enough time for the recipient to develop their own response to the infection. The challenges to use GTXs successfully are both clinical, in terms of timely identifying the patients who may benefit, and logistical, in terms of optimal selection of donors and collection technique.

Granulocyte transfusions in the management of invasive fungal infections

Granulocyte transfusions have a long history of being used in patients with neutropenia or neutrophil dysfunction to prevent and treat invasive fungal infections. However, there are limited and conflicting data concerning its clinical effectiveness, considerable variations in current granulocyte transfusion practices, and uncertainties about its benefit as an adjunct to modern antifungal therapy. In this review, we provide an overview on granulocyte transfusions and summarize the evidence on their role in the prevention and treatment of invasive fungal infections.

Granulocyte transfusions for preventing infections in people with neutropenia or neutrophil dysfunction

BACKGROUND

Despite modern antimicrobials and supportive therapy, bacterial and fungal infections are still major complications in people with prolonged disease-related or therapy-related neutropenia. Since the late 1990s there has been increasing demand for donated granulocyte transfusions to treat or prevent severe infections in people who lack their own functional granulocytes. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effectiveness and safety of prophylactic granulocyte transfusions compared with a control population not receiving this intervention for preventing all-cause mortality, mortality due to infection, and evidence of infection due to infection or due to any other cause in people with neutropenia or disorders of neutrophil function.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) and quasi-RCTs in the Cochrane Central Register of Controlled Trials (Cochrane Library 2015, Issue 3), MEDLINE (from 1946), EMBASE (from 1974), CINAHL (from 1937), theTransfusion Evidence Library (from 1980) and ongoing trial databases to April 20 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing people receiving granulocyte transfusions to prevent the development of infection with a control group receiving no granulocyte transfusions. Neonates are the subject of another Cochrane review and were excluded from this review. There was no restriction by outcomes examined, but this review focuses on mortality, mortality due to infection and adverse events.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

Twelve trials met the inclusion criteria. One trial is still ongoing, leaving a total of 11 trials eligible involving 653 participants. These trials were conducted between 1978 and 2006 and enrolled participants from fairly comparable patient populations. None of the studies included people with neutrophil dysfunction. Ten studies included only adults, and two studies included children and adults. Ten of these studies contained separate data for each arm and were able to be critically appraised. One study re-randomised people and therefore quantitative analysis was unable to be performed.Overall, the quality of the evidence was very low to low across different outcomes according to GRADE methodology. This was due to many of the studies being at high risk of bias, and many of the outcome estimates being imprecise.All-cause mortality was reported for nine studies (609 participants). There was no difference in all-cause mortality over 30 days between people receiving prophylactic granulocyte transfusions and those that did not (seven studies; 437 participants; RR 0.92, 95% CI 0.63 to 1.36, very low-quality evidence).Mortality due to infection was reported for seven studies (398 participants). There was no difference in mortality due to infection over 30 days between people receiving prophylactic granulocyte transfusions and those that did not (six studies; 286 participants; RR 0.69, 95% CI 0.33 to 1.44, very low-quality evidence).The number of people with localised or systemic bacterial or fungal infections was reported for nine studies (609 participants). There were differences between the granulocyte dose subgroups (test for subgroup differences P = 0.01). There was no difference in the number of people with infections over 30 days between people receiving prophylactic granulocyte transfusions and those that did not in the low-dose granulocyte group (< 1.0 x 10(10) granulocytes per day) (four studies, 204 participants; RR 0.84, 95% CI 0.58 to 1.20; very low-quality evidence). There was a decreased number of people with infections over 30 days in the people receiving prophylactic granulocyte transfusions in the intermediate-dose granulocyte group (1.0 x 10(10) to 4.0 x 10(10) granulocytes per day) (4 studies; 293 participants; RR 0.40, 95% CI 0.26 to 0.63, low-quality evidence).There was a decreased number of participants with bacteraemia and fungaemia in the participants receiving prophylactic granulocyte transfusions (nine studies; 609 participants; RR 0.45, 95% CI 0.30 to 0.65, low-quality evidence).There was no difference in the number of participants with localised bacterial or fungal infection in the participants receiving prophylactic granulocyte transfusions (six studies; 296 participants; RR 0.75, 95% CI 0.50 to 1.14; very low-quality evidence).Serious adverse events were only reported for participants receiving granulocyte transfusions and donors of granulocyte transfusions.

AUTHORS' CONCLUSIONS

In people who are neutropenic due to myelosuppressive chemotherapy or a haematopoietic stem cell transplant, there is low-grade evidence that prophylactic granulocyte transfusions decrease the risk of bacteraemia or fungaemia. There is low-grade evidence that the effect of prophylactic granulocyte transfusions may be dose-dependent, a dose of at least 10 x 10(10) per day being more effective at decreasing the risk of infection. There is insufficient evidence to determine any difference in mortality rates due to infection, all-cause mortality, or serious adverse events.

Use of healthy-donor granulocyte transfusions to treat infections in neutropenic patients with myeloid or lymphoid neoplasms: experience in 74 patients treated with 373 granulocyte transfusions

BACKGROUND/AIMS

Despite limited evidence for efficacy, granulocyte transfusions (GTX) are used to prevent and treat opportunistic infections in patients with neutropenia.

METHODS

Three hundred and seventy-three GTX given to 74 patients were assessed retrospectively.

RESULTS

GTX were discontinued because of clinical improvement more often in patients with severe infections than in patients without severe infections (27 vs. 12%; p ≤ 0.002), whereas deaths resulted in discontinuation of GTX therapy less often in patients with severe infections than without (8 vs. 39%; p ≤ 0.002). Patients who died by 12 weeks after GTX initiation were more likely to have leukemia (p = 0.03), not to have recovery of neutrophil counts (p < 0.0001), and to have started GTX during a critical care unit stay (p < 0.001). Uses of granulocyte colony-stimulating factor (p ≤ 0.02) and interferon-γ (p ≤ 0.04) were more common in patients who survived. In patients with comorbidities (31%; odds ratio, OR, 12.6; 95% confidence interval, CI, 2.4-65.7; p ≤ 0.003), GTX was started in the critical care unit (OR 8.8; 95% CI 2.5-30.9; p < 0.001), and a high total bilirubin level at the end of GTX (OR 2.1; 95% CI 1.1-4.2; p = 0.03) had a higher probability of death 12 weeks after GTX therapy commenced.

CONCLUSIONS

The possibility that a niche population may benefit from GTX requires further assessment.

Granulocyte transfusions for preventing infections in patients with neutropenia or neutrophil dysfunction

BACKGROUND

Since the late 1990s there has been increasing demand for donated granulocyte transfusions to treat or prevent severe infections in patients who lack their own functional granulocytes. Other than in neonates, no systematic reviews have been performed for over 10 years relating to the efficacy of prophylactic granulocyte transfusions.

OBJECTIVES

To determine the effectiveness and safety of granulocyte transfusions compared with a control population not receiving this intervention for preventing mortality due to infection or due to any other cause in patients with neutropenia or disorders of neutrophil function.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) Issue 3, 2008, MEDLINE, EMBASE and other specialised databases up to October 2008. We also searched reference lists of articles and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing patients receiving granulocyte transfusions to prevent the development of infection with a control group receiving no granulocyte transfusions. Neonates have been the subject of a recent review and were excluded. There was no restriction by outcomes examined, but this review focuses on mortality, mortality due to infection and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed potentially relevant studies for inclusion. Data were extracted by two review authors and the methodological quality was examined. Data were analysed using random and fixed effects models.

MAIN RESULTS

Ten trials met the inclusion criteria. Allocation in all trials was random, with the control arm receiving no prophylactic therapy, except one trial in which the control group received specific prophylactic antibiotics. One study reported biological randomisation based upon the availability of suitably matched, related donors rather than strict randomisation. All trials were conducted over twenty years ago with one exception, a study from 2006 in which donors were pre-medicated with granulocyte colony stimulating factor (G-CSF) resulting in significantly higher mean doses of granulocytes collected for transfusion. Different policies otherwise applied for the schedule for transfusion, method of granulocyte procurement and criteria for defining infection. Combining the results showed a relative risk (RR) for mortality of 0.94 (95% confidence intervals (CI) 0.71 to 1.25). Exclusion of the two trials which reported transfusion of an average number of granulocytes below 1 x 10(10) indicated a summary RR for mortality and mortality due to infection of 0.89 (CI 0.64 to 1.24) and 0.36 (0.14 to 0.96) respectively.

IMPLICATIONS FOR CLINICAL PRACTICE

The controlled trials that have been identified raise the possibility that prophylactic granulocyte transfusions at a dose of at least 1 x 10(10) may reduce the risk of mortality from infection. Overall mortality was not affected. However, the majority of studies were performed decades ago, and standards of supportive care have advanced considerably. These earlier trials were also based on transfusing lower yields of collected granulocytes than currently recommended. It is difficult to recommend prophylactic granulocyte transfusions outside the setting of ongoing controlled trials, given the resource and cost implications.

IMPLICATIONS FOR RESEARCH

Larger trials are needed to establish the validity of the potential benefits raised by this review, in view of the methodological limitations, the small sample sizes and the heterogeneous definitions of infection that were encountered in the included studies.

Infection control and bone marrow transplantation

BACKGROUND

Bone marrow transplantation for the treatment of malignancies is on the increase. Unfortunately, there are no well-validated infection control guidelines for this highly susceptible population.

METHODS

Literature was reviewed concerning infection risks and interventions to decrease risks for bone marrow transplant recipients.

RESULTS

Definitive information was generally lacking. However, basic "common sense" infection control recommendations for bone marrow transplantation were made in the following areas: air ventilation systems, design issues, environmental services, patient care issues, barrier precautions, nosocomial surveillance, and discharge planning. Recommendations must be tailored to each facility or setting.

CONCLUSION

We conclude that validation of many of these recommendations is necessary to provide optimum care for bone marrow transplant recipients.

The effects of infection prevention regimens on early infectious complications in marrow transplant patients: a four arm randomized study

Three hundred and forty-two patients with hematological malignancies underwent allogeneic marrow transplantation from family donors and were allocated to receive 1) no specific infection prophylaxis in a conventional hospital room (control, 100 patients), 2) prophylactic systemic antibiotics (PSA) in a conventional hospital room (PSA group, 101 patients), 3) decontamination and isolation in a laminar air flow (LAF) room (LAF group, 65 patients) and 4) PSA in an LAF room (LAF+PSA group, 76 patients). Patients were studied for bacterial and fungal complications from the day of admission and until engraftment. LAF isolation was discontinued before engraftment in 27% (LAF+PSA group) to 32% (LAF group) of isolated in 26% (LAF+PSA group) to 27% (PSA group) of patients on prophylactic antibiotics. Septicemia occurred in 41%, 22%, 25% and 10% of patients in the control, PSA, LAF and LAF+PSA group, respectively. The incidence of septicemia was significantly less in the LAF+PSA group than in the control and LAF group with the incidence of septicemia significantly higher in the control group than in any of the other three groups. No other risk factors analyzed in proportional hazards regression tests were associated with septicemia acquisition. It is concluded that effective infection prevention modalities significantly reduce infection morbidity in transplant patients. Since most granulocytopenic transplant patients not receiving PSA will receive empiric or therapeutic broad spectrum antibiotics. The use of PSA in or out of LAF isolation is recommended as an effective modality to reduce septicemia acquisition.

Comparison of a novel trimethoprim-sulfamethoxazole-containing medium (XT80) with kanamycin agar for isolation of antibiotic-resistant organisms from stool and rectal cultures of marrow transplant patients

A new medium (XT80) containing trimethoprim-sulfamethoxazole (TMP-SMZ) was characterized and compared with kanamycin-containing tryptic soy agar (KA) for the recovery of multiply resistant organisms (MRO) in rectal and stool cultures. Cultures from 151 patients hospitalized for bone marrow transplantation were screened for MRO. A total of 366 MRO were recovered from 702 cultures on 94 patients during a 6-month period. XT80 detected more gram-negative bacilli and Corynebacterium spp. than KA. Detection of Staphylococcus spp. was equivalent for the two media. Multiple-antibiotic resistance, defined as resistance to three or more classes of antibiotics, was confirmed by standard agar disk diffusion susceptibility testing. Growth on XT80 correctly identified heteroresistant strains of methicillin-resistant Staphylococcus spp. XT80 more rapidly detected thymidine-dependent mutants of Staphylococcus spp. and members of the family Enterobacteriaceae. Lipophilic Corynebacterium spp., including Corynebacterium group JK, also were more readily detected with XT80. TMP-SMZ given as prophylaxis against Pneumocystis carinii infection exerts a selective pressure on organisms that colonize immunocompromised patients and appears to select for colonization with MRO. Colonization with MRO preceded infection for 94% of 36 patients who developed bacteremia. XT80 is a useful screening tool; growth on this medium correlates closely with resistance to TMP-SMZ and is as accurate a predictor as KA for the carriage of MRO.

Infectious complications in patients undergoing marrow transplantation: a prospective randomized study of the additional effect of decontamination and laminar air flow isolation among patients receiving prophylactic systemic antibiotics

99 patients with hematological malignancies underwent allogeneic marrow transplantation from HLA-identical sibling donors and were randomized to receive one of two forms of infection prophylaxis while granulocytopenic: (1) prophylactic systemic antibiotics in a conventional hospital room (PSA, 50 patients) or (2) decontamination, isolation in a laminar air flow room and the administration of prophylactic systemic antibiotics (LAF + PSA, 49 patients). Only 1 patient (3%) in the LAF + PSA group acquired septicemia while granulocytopenic compared to 11 (24%) patients in the PSA group (p less than 0.005). Three patients (6%) in the LAF + PSA group acquired major localized infections compared to 9 (18%) in the PSA group (p = 0.06). There was no significant difference in days in hospital post transplant, days of granulocytopenia, days of fever, incidence of acute graft-versus-host disease, interstitial pneumonitis or overall survival. We conclude that the use of prophylactic systemic antibiotics added to decontamination and laminar air flow isolation of patients undergoing marrow transplantation significantly reduces the incidence of septicemia in the granulocytopenic period.