Prophylaxis of infection in patients with aplastic anemia receiving allogeneic marrow transplants

Microbiota dynamics in a randomized trial of gut decontamination during allogeneic hematopoietic cell transplantation

BACKGROUNDGut decontamination (GD) can decrease the incidence and severity of acute graft-versus-host disease (aGVHD) in murine models of allogeneic hematopoietic cell transplantation (HCT). In this pilot study, we examined the impact of GD on gut microbiome composition and the incidence of aGVHD in HCT patients.METHODSWe randomized 20 patients undergoing allogeneic HCT to receive (GD) or not receive (no-GD) oral vancomycin-polymyxin B from day -5 through neutrophil engraftment. We evaluated shotgun metagenomic sequencing of serial stool samples to compare the composition and diversity of the gut microbiome between study arms. We assessed clinical outcomes in the 2 arms and performed strain-specific analyses of pathogens that caused bloodstream infections (BSI).RESULTSThe 2 arms did not differ in the predefined primary outcome of Shannon diversity of the gut microbiome at 2 weeks post-HCT (genus, P = 0.8; species, P = 0.44) or aGVHD incidence (P = 0.58). Immune reconstitution of T cell and B cell subsets was similar between groups. Five patients in the no-GD arm had 8 BSI episodes versus 1 episode in the GD arm (P = 0.09). The BSI-causing pathogens were traceable to the gut in 7 of 8 BSI episodes in the no-GD arm, including Staphylococcus species.CONCLUSIONWhile GD did not differentially affect Shannon diversity or clinical outcomes, our findings suggest that GD may protect against gut-derived BSI in HCT patients by decreasing the prevalence or abundance of gut pathogens.TRIAL REGISTRATIONClinicalTrials.gov NCT02641236.FUNDINGNIH, Damon Runyon Cancer Research Foundation, V Foundation, Sloan Foundation, Emerson Collective, and Stanford Maternal & Child Health Research Institute.

Applications of gut microbiota in patients with hematopoietic stem-cell transplantation

Studies of the gut microbiota (GM) have demonstrated the close link between human wellness and intestinal commensal bacteria, which mediate development of the host immune system. The dysbiosis, a disruption of the microbiome natural balance, can cause serious health problems. Patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) may cause significant changes in GM due to their underlying malignancies and exposure to extensive chemotherapy and systemic antibiotics, which may lead to different disorders. There are complex and multi-directional interactions among intestinal inflammation, GM and immune reactivity after HSCT. There is considerable effect of the human intestinal microbiome on clinical course following HSCT. Some bacteria in the intestinal ecosystem may be potential biomarkers or therapeutic targets for preventing relapse and improving survival rate after HSCT. Microbiota can be used as predictor of mortality in allo-HSCT. Two different strategies with targeted modulation of GM, preemptive and therapeutic, have been used for preventing or treating GM dysbiosis in patients with HSCT. Preemptive strategies include enteral nutrition (EN), prebiotic, probiotic, fecal microbiota transplantation (FMT) and antibiotic strategies, while therapeutic strategies include FMT, probiotic and lactoferrine usages. In this review, we summarize the advance of therapies targeting GM in patients with HSCT.

Insights into the role of intestinal microbiota in hematopoietic stem-cell transplantation

The gut microbiota (GM) is able to modulate the human immune system. The development of novel investigation methods has provided better characterization of the GM, increasing our knowledge of the role of GM in the context of hematopoietic stem-cell transplantation (HSCT). In particular, the GM influences the development of the major complications seen after HSCT, having an impact on overall survival. In fact, this evidence highlights the possible therapeutic implications of modulation of the GM during HSCT. Insights into the complex mechanisms and functions of the GM are essential for the rational design of these therapeutics. To date, preemptive and curative approaches have been tested. The current state of understanding of the impact of the GM on HSCT, and therapies targeting the GM balance is reviewed herein.

The gut microbiota and graft-versus-host disease

Graft-versus-host disease (GvHD) is a common complication of hematopoietic cell transplantation that negatively impacts quality of life in recipients and can be fatal. Animal experiments and human studies provide compelling evidence that the gut microbiota is associated with risk of GvHD, but the nature of this relationship remains unclear. If the gut microbiota is a driver of GvHD pathogenesis, then manipulation of the gut microbiota offers one promising avenue for preventing or treating this common condition, and antibiotic stewardship efforts in transplantation may help preserve the indigenous microbiota and modulate immune responses to benefit the host.

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.

Systemic Treatment with a miR-146a Mimic Suppresses Endotoxin Sensitivity and Partially Protects Mice from the Progression of Acute Graft-versus-Host Disease

Acute GVHD (aGVHD) is driven by interactions between the allogenic T cell response, inflammation, tissue injury and microbial products that enter the circulation when protective barriers such as the intestinal epithelium become compromised. Mice with aGVHD become hypersensitive to LPS, secreting large quantities of inflammatory mediators that exacerbate tissue injury. We hypothesized that microRNA (miR) modulators could be used in vivo to mitigate LPS hypersensitivity, altering the course of aGVHD. Using the C57BL/6 → (C57BL/6 × DBA/2)F₁ -hybrid model of aGVHD, we measured intestinal permeability over time and used a qPCR array to detect concomitant changes in the expression levels of certain microRNAs (miRs) in the intestine. Large increases in permeability were seen on day 15, when endotoxemia becomes detectable and GVHD-associated histopathological lesions develop. Amongst the miRs with altered expression levels were some that regulate sensitivity to endotoxin. We chose to focus on miR-146a and treated recipient mice systemically with a miR-146a mimic early in the GVH reaction. This led to a reduction in the burst of IFNγ that likely plays a priming role in the mechanism underlying heightened sensitivity to endotoxin. LPS-induced TNFα release and GVHD-associated weight loss were also diminished and survival was prolonged. In summary, systemic treatment with a miR-146a mimic dampens the heightened sensitivity to LPS that occurs concomitantly with increased intestinal permeability and provides partial protection from the progression of acute GVHD.

Failure of the Sterile Air-Flow Component of a Protected Environment Detected by Demonstration of Chaetomium Species Colonization of Four Consecutive Immunosuppressed Occupants

Four bone marrow transplant recipients consecutively occupying the same room on our Oncology-Hematology Special Care Unit (OHSCU) became colonized with Chaetomium species between January and April, 1987. These patients, aged 27 to 43 years, were immunocompromised as a result of intensive chemotherapy, and were consequently at increased risk for development of invasive fungal infection. At the time of Chaetomium colonization, all patients were febrile, two had transient new infiltrates on chest x-ray, and three were receiving amphotericin B therapy. Subsequent environmental cultures revealed Chaetomium contamination of the OHSCU air-handling system, including the HEPA (high-efficiency particulate air) filters in seven of the nine rooms comprising the unit. Because fungal colonization of HEPA filters used to create a “protective environment” for immunocompromised patients can occur and can serve as a source for patient infections, guidelines concerning proper surveillance of these HEPA filters should be established. We suggest that before a new patient enters a “protected” room, the clean side of the HEPA filter should be cultured. If fungi are recovered from that culture, we would recommend changing the filter.

Microbiota Manipulation With Prebiotics and Probiotics in Patients Undergoing Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is a potentially life-saving therapy that often comes at the cost of complications such as graft-versus-host disease and post-transplant infections. With improved technology to understand the ecosystem of microorganisms (viruses, bacteria, fungi, and microeukaryotes) that make up the gut microbiota, there is increasing evidence of the microbiota's contribution to the development of post-transplant complications. Antibiotics have traditionally been the mainstay of microbiota-altering therapies available to physicians. Recently, interest is increasing in the use of prebiotics and probiotics to support the development and sustainability of a healthier microbiota. In this review, we will describe the evidence for the use of prebiotics and probiotics in combating microbiota dysbiosis and explore the ways in which they may be used in future research to potentially improve clinical outcomes and decrease rates of graft-versus-host disease (GVHD) and post-transplant infection.

Intestinal microbiota-related effects on graft-versus-host disease

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an increasingly important treatment for conditions including hematopoietic malignancies and inherited hematopoietic disorders, and is considered to be the most effective form of tumor immunotherapy available to date. However, graft-versus-host disease (GVHD) remains a major source of morbidity and mortality following allo-HSCT, and understanding the mechanisms of GVHD has been highlighted as a key research priority. During development of GVHD, activation of various immune cells, especially donor T cells, leads to damage of target organs including skin, liver, hematopoietic system, and of particular clinical importance, gut. In addition to histocompatibility complex differences between the donor and recipient, pretransplant conditioning with chemotherapy and irradiation also contributes to GVHD by damaging the gut, resulting in systemic exposure to microbial products normally confined to the intestinal lumen. The intestinal microbiota is a modulator of gastrointestinal immune homeostasis. It also promotes the maintenance of epithelial cells. Recent reports provide growing evidence of the impact of intestinal microbiota on GVHD pathophysiology. This review summarizes current knowledge of changes and effects of intestinal microbiota in the setting of allo-HSCT. We will also discuss potential future strategies of intestinal microbiota manipulation that might be advantageous in decreasing allo-HSCT-related morbidity and mortality.

Safe early discharge for patients undergoing high dose chemotherapy with or without stem cell transplantation: a prospective analysis of clinical variables predictive for complications after treatment

AIM

To identify which patient groups can be safely discharged early after high dose chemotherapy.

BACKGROUND

Until recently, the standard of care for patients with haematological malignancies who have been treated with high dose chemotherapy has been to hospitalise them until neutrophil recovery and clinical improvement. Over the past years, a more liberal approach has resulted in a tendency to discharge patients earlier. However, currently it is unclear which clinical variables are important and which patient groups are most suitable to be discharged early.

DESIGN

Prospective cohort study.

METHODS

The study group of 55 patients underwent 82 admission periods for a total of 2269 patient days, which could be classified into four categories: induction treatment, consolidation treatment and autologous or allogeneic stem cell transplantation. Different clinical variables potentially interfering with early discharge were subsequently analysed for their association with each treatment group.

RESULTS

The median duration of admission was 27 days. The incidence of fever (82.9%) and use of intravenous antibiotics (79.3%) was high in all treatment groups. The only statistically significant differences between groups were found for performance status and mucositis. In the patient group undergoing consolidation chemotherapy for acute myeloid leukaemia, the performance status was better and mucositis was less severe. The decline in performance status and the severity of mucositis were as expected most obvious 10-14 days after the start of chemotherapy.

CONCLUSION

Patients undergoing consolidation chemotherapy appear to be the most suitable candidates for early discharge, especially in the first-week postchemotherapy treatment. Early discharge can also be considered in patients with a good performance status in the autologous stem cell transplantation group, directly after transplantation.

RELEVANCE TO CLINICAL PRACTICE

An important factor in developing an early discharge programme is a good infrastructure, both at home and in the hospital.

Case-control comparison of at-home and hospital care for allogeneic hematopoietic stem-cell transplantation: the role of oral nutrition

BACKGROUND

Acute graft-versus-host disease (GVHD) was reduced using home care compared with hospital care after allogeneic hematopoietic stem-cell transplantation (ASCT).

METHODS

Between March 1998 and December 2006, 601 patients underwent ASCT at our unit. Requirements for at-home ASCT were fulfilled by 76 patients. A control group of 76 patients treated in the hospital were matched for age, sex, diagnosis, stage of disease, conditioning, stem-cell source, type of donor, and immunosuppression. Oral nutrition was determined as median kcal/kg/day for the first 21 days after ASCT.

RESULTS

The home-care patients received more oral nutrition per day than hospital controls (P<0.05). Number of days at home correlated with oral nutrition (P=0.004). In multivariate analysis, acute GVHD of grades II to IV was associated with poor oral nutrition (P=0.003) and hospital care (P=0.06). Transplant-related mortality was associated with acute GVHD grades II to IV (P<0.0001) and bacteremia (P=0.004). In addition to acute GVHD and bacteremia, death was associated with absence of chronic GVHD (P=0.012). Five-year survival was 65% in patients treated at home, when compared with 47% in the controls (P=0.04).

CONCLUSION

Better oral nutrition may be one reason for the reduced probability of acute GVHD and better survival with at-home care than with hospital care.

Mucositis in the cancer patient and immunosuppressed host

Oral mucositis is a serious complication of cancer therapy and in severely immunosuppressed patients. In immunosuppressed patients, the signs and symptoms of infection often are muted because of limited host response, and accurate diagnosis and appropriate treatment may be difficult. Prevention of mucosal breakdown, suppression of microbial colonization, control of viral reactivation, and effective management of severe xerostomia are all critical steps to reducing the overall morbidity and mortality of oromucosal infections.

Risk assessment in haematopoietic stem cell transplantation: GvHD prevention and treatment

Graft-versus-host disease (GvHD) is the major cause of transplant-related mortality and morbidity. As it is closely related to the major therapeutic principle, graft-versus-leukaemia (GvL) effect, risk assessment has to balance both risks depending on the pre-transplant status. This is clearly demonstrated when comparing the two major strategies for prevention of GvHD. While the majority of approaches aiming at T-cell depletion show efficacy in reducing acute and chronic GvHD and transplant-related mortality, T-cell depletion also affects graft-versus-leukaemia effects and thus results in a higher relapse rate. Thus, standard prophylaxis relying on calcineurin inhibitors frequently results in at least equivalent or even superior long-term disease-free survival, and the risk of relapse has to be considered when selecting regimens for prevention of GvHD. In addition to this general dilemma, drug-specific side-effects and risks have to be considered when selecting regimens for GvHD prevention and treatment.

Cause of death after allogeneic haematopoietic stem cell transplantation (HSCT) in early leukaemias: an EBMT analysis of lethal infectious complications and changes over calendar time

We analysed a large homogeneous group of 14,403 patients transplanted for early leukaemia from an HLA-identical sibling and reported to the EBMT in four time cohorts: 1980-1989 (24%), 1990-1994 (26%), 1995-1998 (30%) and 1999-2001 (20%). We focused on death from infection. End points were survival, death from relapse and transplant-related mortality (TRM), which was subdivided into death from graft-versus-host disease (GvHD) (1315 patients; 25% of deaths), infection (597 patients; 11% of deaths) or 'other' causes (1875 patients; 34% of deaths). Survival increased from 52% at 5 years in the first to 62% in the third cohort (P<0.05) and TRM decreased from 36 to 26% (P<0.05) due to a reduction in death from infection (P<0.001). GvHD, 'other' causes and relapse did not improve. The relative proportions of bacteria (217 patients; 36%), viruses (183 patients; 31%), fungi (166 patients; 28%) or parasites (32 patients; 5%) as cause of infectious death (cumulative incidence of death at 5 years 1.8, 1.6, 1.4 and > or = 0.3%, respectively) and median time to death from infections (3 months (range 0-158 months)) did not change. Death from infections has been reduced significantly, but it still represents an ongoing risk after HSCT and draws attention to the time beyond the initial period of neutropenia.

Long-term follow-up of patients treated at home during the pancytopenic phase after allogeneic haematopoietic stem cell transplantation

To prevent neutropenic infections, patients are kept in isolation rooms after allogeneic haematopoietic stem cell transplantation (ASCT). Patients living within one hours' driving distance from our unit were given the opportunity of treatment at home after ASCT during the pancytopenic phase. We compared 36 patients treated at home during March 1998 until December 2000, with 54 controls treated in the hospital during September 1995 and September 2001. The incidence of grades II-IV acute graft-versus-host disease (GVHD) was lower in the home care group compared to the controls, that is, 17 vs 44% (P < 0.01). The cumulative incidence of chronic GVHD was 52% in the home care group, compared to 57% in the controls. Transplant-related mortality (TRM) was 13% in the home care patients vs 44% in the controls (P = 0.002). The probability of relapse was similar in the two groups. The 4-year survival was 63% in the home care patients compared to 44% in the controls (P = 0.04). Home care after ASCT is a novel approach that resulted in less TRM, similar incidence of chronic GVHD and relapse, and improved long-term survival compared to controls treated in the hospital.

Long-term antifungal prophylaxis in high-risk hematopoietic stem cell transplant recipients

The risks for invasive fungal infections, particularly mould infections such as invasive aspergillosis, among hematopoietic stem cell transplant (HSCT) recipients are linked to the duration and severity of myelosuppression and immunosuppression. Strategies to prevent invasive fungal infections have focused primarily on the use of orally administered azole antifungal agents during the neutropenic period rather than on the more prolonged post-engraftment period. The major limitations of these studies included the heterogeneity among the subjects studied for fungal infection risk factors, the agents administered, the dosing, and duration of prophylaxis. More recent studies have attempted to examine the efficacy of antifungal prophylaxis strategies among allogeneic HSCT recipients to day 100 and beyond. It is clear that a variety of products have efficacy in preventing invasive candidiasis, including imidazole and triazole antifungals, low-dose amphotericin B, and the echinocandin, micafungin; however, only the extended spectrum azole, itraconazole, has been shown to impact the incidence of proven invasive aspergillosis. Other extended spectrum azole antifungal agents, voriconazole and posaconazole, are being studied as long-term prophylaxis in high-risk HSCT recipients. While clinical trials have suggested that a duration of prophylaxis against moulds of six months or more may be required, it remains unclear if this is required in all cases. The prophylactic efficacy over time may be linked to the degree of immunosuppression as measured by markers such as the numbers of circulating CD4 T lymphocytes. Concerns about selection for resistant moulds among long-term recipients of these drugs are emerging. The cumulative experience to date suggests that long-term antifungal chemoprophylaxis is feasible and effective when applied in defined circumstances. The concerns about treatment-related toxicities, resistance, and costs are valid.

Is it safe to treat allogeneic stem cell transplanted recipients at home during the pancytopenic phase?

BACKGROUND

After myeloablative treatment and allogeneic stem cell transplantation (ASCT), patients are kept isolated in the hospital to prevent infections during neutropenia.

METHODS

So far, 22 patients have been given the choice of being treated at home. Eleven could not be treated at home, and they served as controls. Most of them had haematological malignancies. The donors were 12 HLA-compatible unrelated, 9 HLA-identical siblings and one twin.

RESULTS

In the home care group, 3 developed bacteraemia, compared to 9 in the controls (p<0.01). The patient in the home care group had fewer days on total parenteral nutrition (median 3 vs. 24, p<0.001), required fewer erythrocyte transfusions (median 4 vs. 8, p=0.01), fewer days on i.v. antibiotics (median 6 vs. 13 days), and on analgesics (median 0 vs. 15) than the controls (p<0.05). Days with fever, time to engraftment, days with G-CSF and acute GVHD were the same in the two groups. 7/11 patients treated at home were readmitted to the ward for median 3 (0-7) days, due to fever or lack of a caregiver at home. Days to discharge to the out-patient clinic was faster in the group treated at home (median 20 vs 35 days, p<0.01).

DISCUSSION

Patients who were treated at home enjoyed being active and taking a walk when they felt like it. This preliminary report suggests that home care after ASCT is not only safe, but better than isolation in the hospital.

Immune suppression and considerations for dental care

Immunocompromised individuals present a challenge to oral health care providers. As the spectrum of patients with dysfunctional immune responses continues to broaden, practitioners should be able to identify these patients, understand the potential for complications, and manage their dental care safely and effectively. This article reviews various immune deficiencies, addresses complications that may result from an individual's immune status, and discusses dental considerations for these patients.

Home care during the pancytopenic phase after allogeneic hematopoietic stem cell transplantation is advantageous compared with hospital care

After myeloablative treatment and allogeneic stem cell transplantation (SCT), patients are kept in isolation rooms in the hospital to prevent neutropenic infections. During a 3-year period, patients were given the option of treatment at home after SCT. Daily visits by an experienced nurse and daily phone calls from a physician from the unit were included in the protocol. We compared 36 patients who wished to be treated at home with 18 patients who chose hospital care (control group 1). A matched control group of 36 patients treated in the hospital served as control group 2. All home care patients had hematologic malignancies and 19 were in first remission or first chronic phase. Of the donors, 25 were unrelated. The patients spent a median of 16 days at home (range, 0-26 days). Before discharge to the outpatient clinic after SCT, patients spent a median of 4 days (range, 0-39 days) in the hospital. In the multivariate analysis, the home care patients were discharged earlier (relative risk [RR] 0.33, P =.03), had fewer days on total parenteral nutrition (RR 0.24, P <.01), less acute graft-versus-host disease (GVHD) grades II-IV (RR 0.25, P =.01), lower transplantation-related mortality rates (RR 0.22, P =.04), and lower costs (RR 0.37, P <.05), compared with the controls treated in the hospital. The 2-year survival rates were 70% in the home care group versus 51% and 57% (not significant) in the 2 control groups, respectively (P <.03). To conclude, home care after SCT is a novel and safe approach. This study found it to be advantageous, compared with hospital care.

Periodontal disease and periodontal management in patients with cancer

Periodontal infection may exacerbate during cancer therapy and may result in oral pain and infection, and systemic infection, which may cause morbidity and can lead to mortality in neutropenic cancer patients. Periodontal disease in head and neck cancer patients treated with radiation therapy may lead to acute and chronic complications. The literature was reviewed by a search of Medline of the National Library of Medicine. The search was conducted to identify publications assessing periodontal disease in cancer patients. In addition, a review of papers referenced in the retrieved papers was conducted to identify additional publications for review. Periodontal disease should be assessed and managed prior to medical treatment of cancer for those with oropharyngeal cancer, and for patients in whom neutropenia may develop during treatment. Pretreatment assessment and management, and maintenance of oral hygiene have been shown to be effective in preventing oral and systemic complications during treatment. A complete oral and periodontal examination is appropriate for all patients planned to receive head and neck radiation therapy and those to be treated with medical protocols that are anticipated to result in neutropenia. Oral and periodontal care must continue following cancer therapy, and requires that the health care provider have an understanding of the malignant disease, oral manifestations of the disease, medical management of the disease, and of the oral complications that may develop.

Nosocomial Pneumonia is Not Prevented by Protective Contact Isolation in the Surgical Intensive Care Unit

Nosocomial pneumonia (NP) is the leading cause of death from hospital-acquired infection in intubated surgical intensive care unit (SICU) patients. To determine whether protective contact isolation would lower the incidence of NP in intubated patients we performed a prospective, randomized, and controlled study in two SICUs in a tertiary medical center. Over a period of 15 months two identical ten-bed SICUs alternated for 3-month periods between protective contact isolation (isolation group) and standard “universal precautions” (control group). In the isolation group all personnel and visitors donned disposable gowns and nonsterile gloves before entering an intubated patient's room; handwashing was required before entry and on leaving the room. In the control group caregivers utilized only “standard precautions” including handwashing and nonsterile gloves for intubated patients. Respiratory cultures were obtained 48 hours after SICU admission and every 48 hours thereafter until extubation, transfer to floor care, or death. Airway colonization (AC) occurred in 72.7 per cent of isolated patients and 69.0 per cent of control patients ( P = 0.61). The incidence of NP was significantly higher in the isolation group (36.4%) compared with the control group (19.5%) ( P = 0.02). There was no statistically significant difference between groups in days from SICU admission to AC, days to NP, and mortality. We conclude that protective contact isolation with gowns, gloves, and handwashing is not superior to gloves and handwashing alone in the prevention of AC and NP in SICU patients and may in fact be detrimental.

Is it safe to treat allogeneic stem cell transplant recipients at home during the pancytopenic phase? A pilot trial

After myeloablative treatment and allogeneic stem cell transplantation (ASCT), patients are kept isolated in the hospital to prevent infections during neutropenia. To date, 22 patients have been given the choice of being treated at home. Eleven could not be treated at home, and they served as controls. Most had haematological malignancies. The donors were 12 HLA-compatible unrelated, nine HLA-identical siblings and one twin. In the home care group, three developed bacteraemia, compared to nine in the controls (P < 0.01). Patients in the home care group had fewer days of total parenteral nutrition (median 3 vs 24, P < 0.001), required fewer erythrocyte transfusions (median 4 vs 8, P = 0.01), fewer days on i.v. antibiotics (median 6 vs 13 days), and on analgesics (median 0 vs 15) than the controls (P < 0.05). Days with fever, time to engraftment, days with G-CSF and acute GVHD were the same in the two groups. Seven of 11 patients treated at home were readmitted to the ward for a median of 3 (0-7) days, due to fever or lack of a caregiver at home. Days to discharge to the out-patient clinic were faster in the group treated at home (median 20 vs 35 days, P < 0.01). Patients who were treated at home enjoyed being active and taking a walk when they felt like it. This preliminary report suggests that home care after ASCT is not only safe, but superior to isolation in the hospital.

Oral complications associated with immunosuppression and cancer therapies

The oral manifestations of oropharyngeal infection in immunocompromised patients present a particular challenge for both medical and dental professionals because clinical signs and symptoms may be minimal and accurate diagnosis and appropriate treatment may be difficult. Effective control of infection and management of oral symptoms are important and may be achieved by the judicious use of topical and systemic agents and by maintaining good oral hygiene. Prevention of mucosal breakdown, suppression of microbial colonization, control of viral reactivation, and effective management of severe xerostomia are all critical steps to reduce the overall morbidity and mortality of oromucosal infections in the severely immunocompromised patient.

Prevention of infection in the immunocompromised host

The Association for Professionals in Infection Control and Epidemiology, Inc, is accredited as a provider of continuing education in nursing by the American Nurses Credentialing Center's Commission on Accreditation. This learner-paced study package is designated for 1.1 contact hours. APIC's California nursing provider number is CEP 7146. This continuing medical laboratory education activity is recognized by the American Society of Clinical Pathologists as meeting the criteria for 1 CMLE credit hour. ASCP CMLE credit hours are acceptable to meet the continuing education requirements for the ASCP Board of Registry Continuing Competence Recognition Program. (See the instructions and examination at the end of the article.)Infectious diseases represent a major cause of morbidity and mortality in immunocompromised patients. Infectious complications are often predictable and may be preventable. This article is an overview of practical considerations in the care of immunocompromised patients. Recognizing the compromised host, identifying and correcting risk factors in advance, and reducing sources of infection all play a role in prevention. Topics were chosen to include the areas of care that differ from the immune competent patient, such as diet, pet therapy, handwashing, immunizations, augmentation of host resistance, prevention of pneumonia, and antibiotic prophylaxis. National practice guidelines are cited when possible; evidence-based literature review and experience are applied to situations lacking consensus statements. Treatment decisions are made in areas for which information is often incomplete. A systematic approach to care of the immunocompromised host, tailored to the individual patient's needs, should reduce the risk of infection.

Isolation in BMT: a protection or a privation?

Bone marrow transplantation (BMT) is an increasingly important therapy not only in the treatment of haematological oncology, but also of solid tumours. How best to protect the profoundly immunosuppressed transplant patient is controversial. This article presents a brief resume of the literature on isolation in BMT and an account of observations made by the author when visiting a selection of BMT centres in the UK, USA and Canada.

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.

Allogeneic bone-marrow transplantation without protective isolation in adults with malignant disease

Bone-marrow transplant (BMT) patients are severely immunocompromised immediately after the procedure and they are commonly nursed in strict protective isolation to reduce the risk of both infection and graft-versus-host disease (GvHD). We have studied a consecutive series of patients to see whether protective isolation is of benefit as prophylaxis against infectious complications of BMT. 50 consecutive patients who had malignant disease and received their first BMT from siblings or unrelated donors were nursed in standard single rooms with visitors instructed to wash their hands. A subset of 20 patients living locally spent a median of 25 days in hospital after BMT; they also spent some time at home on a median of 8 days before engraftment and 3 patients went home on more than 90% of their hospital days. 16 patients (32%) had positive bacterial cultures and/or focal infection. Gram-positive bacteraemia was found in 12 subjects (24%) but there were no gram-negative or deep fungal infections. Grade II or III acute GvHD developed in 17 patients (34%). There were no deaths from infection or acute GvHD. Transplant-related mortality was 6% in the first 100 days and 18% overall with a median follow-up of 22 months. Our mortality data compare favourably with those from institutions with strict isolation procedures. We conclude that BMT may be safely completed in some institutions without either protective isolation or the need to confine patients continuously in hospital.

Glutamine-enriched intravenous feedings attenuate extracellular fluid expansion after a standard stress

A double-blind, randomized controlled trial was performed to determine the effect of glutamine (GLN)-enriched intravenous feedings on the volume and distribution of body fluids in catabolic patients. Subjects with hematologic malignancies in remission underwent a standard treatment of high-dose chemotherapy and total body irradiation before bone marrow transplantation. After completion of this regimen, they were randomized to receive either standard parenteral nutrition (STD, n = 10) or an isocaloric, isonitrogenous nutrient solution enriched with crystalline L-glutamine (0.57 g/kg/day, GLN, n = 10). Extracellular water (ECW) and total body water (TBW), determined by bromide and heavy water dilution techniques, were measured before the conditioning treatment and after termination of the intravenous feedings that were administered for 27 +/- 1 days. In addition electrical resistance (R, in ohms, omega) and reactance (Xc, omega) of the body to a weak alternating current were measured at these time points. Both study groups were comparable for age, weight, height, sex, and diagnosis. Initial TBW was highly related to electrical resistance (r = -0.93, p less than 0.001). After conditioning therapy, bone marrow infusion, and intravenous feedings, a 20% expansion in ECW was observed in the STD group (ECW: 18.0 +/- 1.1 L vs. 14.9 +/- 1.0, p = 0.012), and this fluid retention was associated with a marked decrease in electrical resistance (R: 514 +/- 28 omega vs. 558 +/- 26, p less than 0.05). In contrast the extracellular fluid compartment in patients receiving GLN-supplementation did not change (ECW: 15.8 +/- 0.9 L vs. 15.4 +/- 0.8, p = 0.49), and the body's resistance was maintained (R: 552 +/- 27 omega vs. 565 +/- 23, p = 0.42). Expansion of ECW could not be related to differences in fluid or sodium intake, or to the use of diuretics or steroids. Patients receiving the STD solution, however, exhibited a greater number of positive microbial cultures (p less than 0.01) and a higher rate of clinical infection compared with the GLN patients (5/10 vs. 0/10, p less than 0.05); the fluid expansion in infected STD patients was greater compared with uninfected individuals (delta ECW: + 5.0 +/- 1.4 vs. 0.7 +/- 0.5, p = 0.007). In this model of catabolic stress, fluid retention and expansion of the extracellular fluid compartment commonly observed after standard total parenteral nutrition can be attenuated by administering glutamine-supplemented intravenous feedings, possibly by protecting the host from microbial invasion and associated infection.

Immunomodulatory and antimicrobial efficacy of intravenous immunoglobulin in bone marrow transplantation

BACKGROUND

Graft-versus-host disease (GVHD) and infection are major complications of allogeneic bone marrow transplantation. Since intravenous immunoglobulin has shown benefit in several immunodeficiency and autoimmune disorders, we studied its antimicrobial and immunomodulatory role after marrow transplantation.

METHODS

In a randomized trial of 382 patients, transplant recipients given immunoglobulin (500 mg per kilogram of body weight weekly to day 90, then monthly to day 360 after transplantation) were compared with controls not given immunoglobulin. By chance, the immunoglobulin group included more patients with advanced-stage neoplasms; otherwise, the study groups were balanced for prognostic factors.

RESULTS

Control patients seronegative for cytomegalovirus who received seronegative blood products remained seronegative, but seronegative patients who received immunoglobulin and screened blood had a passive transfer of cytomegalovirus antibody (median titer, 1:64). Among the 61 seronegative patients who could be evaluated, none contracted interstitial pneumonia; among the 308 seropositive patients evaluated, 22 percent of control patients and 13 percent of immunoglobulin recipients had this complication (P = 0.021). Control patients had an increased risk of gram-negative septicemia (relative risk = 2.65, P = 0.0039) and local infection (relative risk = 1.36, P = 0.029) and received 51 more units of platelets than did immunoglobulin recipients. Neither survival nor the risk of relapse was altered by immunoglobulin. However, among patients greater than or equal to 20 years old, there was a reduction in the incidence of acute GVHD (51 percent in controls vs. 34 percent in immunoglobulin recipients; P = 0.0051) and a decrease in deaths due to transplant-related causes after transplantation of HLA-identical marrow (46 percent vs. 30 percent; P = 0.023).

CONCLUSIONS

Passive immunotherapy with intravenous immunoglobulin decreases the risk of acute GVHD, associated interstitial pneumonia, and infections after bone marrow transplantation.

Supportive care of the marrow transplant recipient: the Seattle Experience

It is now almost 2 decades after the first successful human marrow transplants from HLA-identical siblings for the treatment of life-threatening hematologic diseases. Results have improved, especially for patients transplanted earlier in the course of disease. However, major problems remain in supporting patients through the transplant. More effective and less toxic conditioning regimens are needed. Acceleration of hematopoietic and immunologic reconstitution by use of various cytokines holds promise for decreasing infectious morbidity and mortality. Improved regimens to control acute and chronic GVHD and prevent opportunistic infections will play a major role in the advancement of supportive care of the marrow transplant recipient.

Prevention of infection and graft-versus-host disease by suppression of intestinal microflora in children treated with allogeneic bone marrow transplantation

The effect of suppression with antimicrobial agents of the intestinal microflora of paediatric bone marrow graft recipients on severe bacterial and fungal infections and on moderate to severe acute graft-versus-host disease was studied retrospectively. Data on 65 cases of bone marrow transplantation for either severe bone marrow failure or leukaemia, performed in a strict protective environment with either complete or selective gastrointestinal decontamination, were evaluated. All bone marrow grafts were from HLA-identical siblings and were not depleted of T-lymphocytes. Twenty percent of the recipients had one or more episodes of septicaemia during the granulocytopenic period after transplantation, mostly due to gram-positive bacteria. Only five children died due to infection, in each case caused by a microorganism originating from the endogenous flora. Complete gastrointestinal decontamination was superior to selective gastrointestinal decontamination in preventing infectious complications (p less than 0.001). The same was the case for the prevention of acute graft-versus-host disease of grade II or higher, which was observed in 7 of 40 (17.5%) completely decontaminated children versus 9 of 18 (50%) selectively decontaminated children evaluable for graft-versus-host disease (p less than 0.01). It is concluded that complete gastrointestinal decontamination in a strict protective environment is a feasible and very effective method for preventing severe infections and acute graft-versus-host disease after allogeneic bone marrow transplantation in children and adolescents; it resulted in a low transplantation-related mortality of 26% and a good quality of survival in 69% of the graft recipients.

Reduction of nosocomial infection during pediatric intensive care by protective isolation

To determine whether simple protective isolation reduces the incidence of nosocomial bacterial and fungal infection during pediatric intensive care, we randomly assigned 70 children who were not immuno-suppressed and who required mechanical ventilatory support and three or more days of intensive care to receive standard care (n = 38) or protective isolation (n = 32) with use of disposable, non-waven, polypropylene gowns and nonsterile latex gloves. Risk factors predisposing patients to infection were comparable in the two groups. Nosocomial colonization occurred later among isolated patients (median, vs. 7 days; P less than 0.01) and was associated with subsequent infection in 12 patients, as compared with 12 patients given standard care (P = 0.01). Among patients who were isolated, the interval before the first infection was significantly longer than (median, 20 vs. 8 days; P = 0.04), the daily infection rate was 2.2 times lower than (95 percent confidence interval, 1.2 to 4.0; P = 0.007), and there were fewer days with fewer (13 percent vs. 21 percent; P = 0.001). The benefit of isolation was most notable after seven days of intensive care. Isolation was well tolerated by patients and their families. Regular monitoring showed that the children in each group were touched and handled comparably often by hospital personnel and family members. We conclude that the use of disposable, high-barrier gowns and gloves for the care of selected, high-risk children who require prolonged intensive care significantly reduces the incidence of nosocomial infection, is well tolerated, and does not compromise the delivery of care.

Infectious complications after allogeneic bone marrow transplantation with and without T-cell depletion of donor marrow

The infectious complications during different time intervals after allogeneic bone marrow transplantation (BMT) (day 0 to day 30, 31 to 100, 101 to 365, 366 to 730) were reviewed in 67 adult patients, 27 of whom received transplants without T-cell depletion (TCD) using methotrexate or cyclosporin A for prophylaxis of graft-versus-host disease (GvHD) and 40 of whom received donor marrow with TCD using the monoclonal anti-lymphocyte antibody campath-1 and human complement. The use of TCD reduced the incidence and severity of GvHD significantly (p less than 0.01), but was associated with an increased rate of graft rejections. During all time intervals patients with TCD had a similar, lower or statistically significantly lower number of bacterial, fungal or viral infections and a statistically significantly lower number of lethal infections (p = 0.05) as compared with patients without TCD. This finding might be explained by the fact that with TCD immunological reconstitution can take place unimpaired by GvHD or its prophylaxis or treatment, resulting in a decreased incidence of infections.

Measurement of bacterial and fungal air counts in two bone marrow transplant units

We evaluated air contamination with bacteria and fungi in a transplantation unit, successively housed in two buildings. Bacterial air contamination was least in laminar air flow rooms, and reduced in ultraclean air rooms in comparison with conventional rooms. Similar results were obtained with culture of air for fungi.

The potential benefit of granulocyte transfusion therapy

The future of granulocyte transfusions depends in large part upon our ability to overcome technical problems, particularly related to dose. Certainly the attempts at technical improvements have made an impact on granulocyte availability and donor pools large enough to support twice daily transfusions should also improve the efficacy of a series of transfusions. The majority of bacterial infections in neutropenic patients do not necessitate granulocyte transfusions due to the rapid empiric use of modern broad-spectrum antibiotics. However, a proportion still do, and selection of appropriate candidates for granulocyte transfusions may improve the outcome. The use in fungal infections remains experimental, but as has been said by others in addition to myself, should be studied. Issues of histocompatibility remain complex. Patients rendered severely immunocompromised may have less of an alloimmunization response to transfusion products, but alloimmunization continues to be a complication of granulocyte transfusions. Patients undergoing bone marrow transplant have the advantage of access to an HLA-matched marrow and granulocyte donor. The techniques of granulocyte transfusion therapy must continue to be improved and utilized in part because our microbial foes continue to change and to resist our antibiotic improvements. As George Bernard Shaw said: "There is at bottom only one genuinely scientific treatment for all diseases and that is to stimulate the phagocytes. Drugs are a delusion".

Failure of the sterile air-flow component of a protected environment detected by demonstration of Chaetomium species colonization of four consecutive immunosuppressed occupants

Four bone marrow transplant recipients consecutively occupying the same room on our Oncology-Hematology Special Care Unit (OHSCU) became colonized with Chaetomium species between January and April, 1987. These patients, aged 27 to 43 years, were immunocompromised as a result of intensive chemotherapy, and were consequently at increased risk for development of invasive fungal infection. At the time of Chaetomium colonization, all patients were febrile, two had transient new infiltrates on chest x-ray, and three were receiving amphotericin B therapy. Subsequent environmental cultures revealed Chaetomium contamination of the OHSCU air-handling system, including the HEPA (high-efficiency particulate air) filters in seven of the nine rooms comprising the unit. Because fungal colonization of HEPA filters used to create a "protective environment" for immunocompromised patients can occur and can serve as a source for patient infections, guidelines concerning proper surveillance of these HEPA filters should be established. We suggest that before a new patient enters a "protected" room, the clean side of the HEPA filter should be cultured. If fungi are recovered from that culture, we would recommend changing the filter.

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.

Norfloxacin for prevention of bacterial infections during severe granulocytopenia after bone marrow transplantation

48 patients treated with bone marrow transplantation (BMT) received the quinolone norfloxacin (NOR) in a total decontamination (TD-NOR, n = 36) or selective decontamination (SD-NOR, n = 12) regimen and were compared with a historical control group of 48 BMT patients receiving oral non-absorbable antibiotics (TD-NAA, n = 31 and SD-NAA, n = 17). 17/36 patients (47%) of group TD-NOR and 16/31 patients (52%) of group TD-NAA remained free of febrile episodes and infections. 4/12 patients (33%) of group SD-NOR and only 1/17 patients (6%) of group SD-NAA remained free of fever and infections. The use of norfloxacin in selective decontamination resulted in a statistically significant lower incidence of fever days than in patients receiving SD-NAA (p less than 0.001). These data suggest that norfloxacin may replace non-absorbable antibiotics in total and in selective decontamination regimens used for infection prophylaxis in BMT recipients.