Non-Candida fungal infections after bone marrow transplantation: risk factors and outcome

Risk factors for invasive fungal infections after haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Invasive fungal infections (IFIs) are common infectious complications after haematopoietic stem cell transplantation (HSCT), seriously threatening the survival of patients.

OBJECTIVES

This systematic review aimed to investigate risk factors associated with IFIs following HSCT.

METHODS

Two authors independently conducted the selection of studies and extraction of data. Risk factors for IFIs, invasive aspergillosis or invasive mould infections and invasive candida infection after HSCT were compiled separately by meta-analysis using RevMan 5.4 and R language 4.1.2.

DATA SOURCES

Pubmed, EMBASE, Web of Science, and the Cochrane Library until April 2023.

STUDY ELIGIBILITY CRITERIA

Case-control or cohort studies that assessed risk factors for IFIs among HSCT recipients were included.

PARTICIPANTS

Patients experiencing HSCT.

TEST/S

None.

REFERENCE STANDARD

The IFIs were defined according to the European Organisation for Research and Treatment of Cancer/Mycosis Study Group (EORTC/MSG) criteria, or a similar definition.

ASSESSMENT OF RISK OF BIAS

A modified version of the Newcastle-Ottawa Scale was used.

METHODS OF DATA SYNTHESIS

A random-effects model with the Mantel-Haenszel method was used to pool results from primary studies.

RESULTS

Out of 1637 studies screened, 51 studies involving 109 155 patients were included, with 45 studies providing adequate data for meta-analysis. Identified risk factors for IFIs included prolonged neutropenia, intensified therapy for graft-versus-host disease (GVHD), previous transplantation, previous proven or probable IFI, acute GVHD ≥ grade II, extensive or severe chronic GVHD, use of anti-thymocyte globulin during transplantation, haploidentical transplantation, high-dose glucocorticoids, Epstein-Barr virus infection, cytomegalovirus infection or reactivation, and lower albumin. Conversely, antifungal prophylaxis emerged as the sole preventive factor. For invasive aspergillosis or invasive mould infections, the top risk factors were extensive or severe chronic GVHD, respiratory viral infection, high-dose glucocorticoids, acute GVHD ≥ grade II, and human leukocyte antigen mismatch. Cord blood transplantation was the sole significant risk factor for invasive candidiasis. However, there was likely a high degree of interdependence among various risk factors.

DISCUSSION

This meta-analysis provides a thorough review of risk factors for IFIs infection after HSCT. The achieved insights can aid in stratifying patients who are at an elevated risk of IFIs and promoting antifungal preventive strategies.

Dexamethasone and Methylprednisolone Promote Cell Proliferation, Capsule Enlargement, and in vivo Dissemination of C. neoformans

Cryptococcus neoformans is a fungal pathogen that causes life-threatening infections in immunocompromised individuals, who often have some inflammatory condition and, therefore, end up using glucocorticoids, such as dexamethasone and methylprednisolone. Although the effects of this class of molecules during cryptococcosis have been investigated, their consequences for the biology of C. neoformans is less explored. Here, we studied the effects of dexamethasone and methylprednisolone on the metabolism and on the induction of virulence factors in C. neoformans. Our results showed that both glucocorticoids increased fungal cell proliferation and surface electronegativity but reduced capsule and secreted polysaccharide sizes, as well as capsule compaction, by decreasing the density of polysaccharide fibers. We also tested whether glucocorticoids could affect the fungal virulence in Galleria mellonella and mice. Although the survival rate of Galleria larvae increased, those from mice showed a tendency to decrease, with infected animals dying earlier after glucocorticoid treatments. The pathogenesis of spread of cryptococcosis and the interleukin secretion pattern were also assessed for lungs and brains of infected mice. While increases in the spread of the fungus to lungs were observed after treatment with glucocorticoids, a significant difference in brain was observed only for methylprednisolone, although a trend toward increasing was also observed for dexamethasone. Moreover, increases in both pulmonary and cerebral IL-10 production, reduction of IL-6 production but no changes in IL-4, IL-17, and INF-γ were also observed after glucocorticoid treatments. Finally, histopathological analysis confirmed the increase in number of fungal cells in lung and brain tissues of mice previously subjected to dexamethasone or methylprednisolone treatments. Together, our results provide compelling evidence for the effects of dexamethasone and methylprednisolone on the biology of C. neoformans and may have important implications for future clinical treatments, calling attention to the risks of using these glucocorticoids against cryptococcosis or in immunocompromised individuals.

Cutaneous phaeohyphomycosis in a hematopoietic stem cell transplant patient caused by Alternaria rosae: First case report

Alternaria species have been reported as a rare cause of fungal infection in organ and stem cell transplant recipients, but to date, no reports have been published of infection in humans caused by Alternaria rosae. Here, we report cutaneous A. rosae infection in a 66-year-old farmer with a history of primary myelofibrosis who had undergone allogeneic unrelated donor hematopoietic stem cell transplantation. Forty-nine days post transplant, he presented with a nodule on the thumb with no findings suggestive of disseminated infection. Pathology, culture, and molecular speciation showed the nodule was caused by cutaneous A. rosae. He had been on voriconazole as antifungal prophylaxis, but was found to have a subtherapeutic voriconazole level. He was switched to posaconazole based on published in vitro data showing its superior efficacy in Alternaria treatment. Susceptibility testing showed that the A. rosae isolate was indeed susceptible to posaconazole. His cutaneous lesion remained stable, but he died from respiratory failure secondary to lobar pneumonia. At lung autopsy, A. rosae was not identified in the lungs. We believe this to be the first published report, to our knowledge, of A. rosae infection in humans.

Cryptococcus laurentii diarrhea post hematopoietic stem cell transplant

We report the recent isolation of Cryptococcus laurentii from the feces of a patient with Hodgkin's lymphoma who underwent autologous hematopoietic stem cell transplant (HSCT). The organism was identified using microscopic morphology, cultural characteristics, and biochemical tests including sugar assimilation. Minimum inhibitory concentration of various antifungals was determined by microbroth dilution method. The recovery of pure culture of C. laurentii from stool culture, and the patient's response to treatment with voriconazole support its potential etiological role. To the best of our knowledge, we report the first case of diarrhea caused by C. laurentii in an HSCT recipient.

Cutaneous Emboli of Invasive Basidiomycosis in a Child With Aplastic Anemia

Invasive fungal diseases are a significant cause of mortality among the immunocompromised. This report documents an unusual case of disseminated fungal infection in a child with severe aplastic anemia. The offending fungus, a Basidiomycete, is rarely known to cause human infections. The patient presented acutely with multiple purpuric skin lesions in various parts of the body. The skin biopsy revealed septated fungal hyphae embolized within small dermal blood vessels. Molecular sequencing indicated Earliella scabrosa as the likely organism. The clinical course of the infection was inexorable despite systemic antifungal treatment, resulting in mortality. The literature of human infections due to Basidiomycetes, the usefulness of histopathology in the early diagnosis of the infection, and possible treatment options are discussed.

Prevention of Fungal Infections in Hematology Patients

Endogenous infections such as candidiasis can be minimized by oral fluconazole prophylaxis, although oral or intravenous amphotericin, or itraconazole, are suitable for certain patients. Exogenous fungal infections most commonly are transmitted by the airborne route, but the benefits of high-efficiency particulate air-filtered room air probably are diminishing as broad-spectrum prophylaxis againstAspergillusspecies and other fungi improves. However, high-risk environmental sources such as construction work always must be avoided near neutropenic patients. Reactivation of quiescent pulmonaryAspergillusinfection can be prevented by surgical resection during remission, or by systemic amphotericin prophylaxis during subsequent neutropenic episodes.

Guideline for primary antifungal prophylaxis for pediatric patients with cancer or hematopoietic stem cell transplant recipients

This guideline provides clinicians with evidence-based recommendations on the use of antifungal prophylaxis in children with cancer and undergoing hematopoietic stem cell transplantation (HSCT). Recommendations are divided into: (1) allogeneic HSCT (2) autologous HSCT (3) acute myeloid leukemia or myelodysplastic syndrome and (4) patients with malignancy and neutropenia for >7 days. A systematic review was conducted and evidence summaries compiled. The quality of evidence and strength of each recommendation was determined using GRADE. Implementation of these recommendations will require adaptation to local context. The contribution of this guideline in the prevention of invasive fungal infections requires prospective evaluation.

[Place of surgery in pulmonary aspergillosis and other pulmonary mycotic infections]

Surgery is part of the therapeutic strategy of aspergillosis and mucormycosis. The aspergilloma is defined as a rounded mass, developing in a cavity by the proliferation of spores of Aspergillus. The most common complication was haemoptysis reported in 50-95% of cases. The pleuropulmonary lesions predisposing are: tuberculosis, residual pleural space, emphysema and lung destroyed by fibrosis or radiotherapy or bronchiectasis. The indications for surgery depend on symptoms, respiratory function, the parenchyma and the type of aspergilloma (simple or complex). In a patient with an intrapulmonary aspergilloma, lung resection preceded by embolization is recommended based on respiratory function. For intrapleural aspergilloma, thoracoplasty is recommended according to the patient's general condition. The invasive pulmonary aspergillosis (IPA) is characterized by an invasion of lung tissue and blood vessels by hyphae in immunocompromised patients. The death rate of patients who have an API after treatment for leukemia or lymphoma was 30 to 40%, after bone marrow transplantation 60%, after solid organ transplantation from 50 to 60% and after any other cause of immunocompromising from 70 to 85%. The main cause of these deaths is massive hemoptysis. Surgery (lobectomy) is indicated for the prevention of hemoptysis when the mass is in contact with the pulmonary artery or one of its branches, and if it increases in size with the disappearance of border security between the mass and the vessel wall. The patient will be operated in an emergency before the white blood cells do not exceed the threshold of 1000 cells/μl. A persistent residual mass after antifungal treatment may justify a lung resection (lobectomy or wedge) before a new aggressive therapy. Mucormycosis affects patients following immunocompromising states--haematologic malignancy, diabetes mellitus, transplantation, burns and malnutrition. The treatment of pulmonary mucormycosis combines surgical and medical approach.

Infections in pediatric transplant recipients: not just small adults

Transplantation increasingly is being used as treatment for children with end-stage organ diseases, hematopoietic rescue from therapy used to treat malignancies, and as cure for primary immune deficiencies. This article reviews some of the major concepts regarding infections that complicate pediatric transplantation, highlighting differences in epidemiology, evaluation, treatment and prevention for children compared with adult recipients.

Diagnosis and management of infectious complications in critically ill patients with cancer

Cancer and its treatments lead to profound suppression of innate and acquired immune function. In this population, bacterial infections are common and may rapidly lead to overwhelming sepsis and death. Furthermore, infections caused by viral and fungal pathogens should be considered in patients who have specific immune defects. As cancer therapies have become more aggressive the risk for infection has increased and many patients require intensive care support. Despite improvements in long-term survival, infections remain a common complication of cancer therapy and accounts for the majority of chemotherapy-associated deaths. By understanding the host defense impairments and likely pathogens clinicians will be better able to guide diagnosis and management of this unique population.

Reconstitution of the immune system after hematopoietic stem cell transplantation in humans

Hematopoietic stem cell transplantation is associated with a severe immune deficiency. As a result, the patient is at high risk of infections. Innate immunity, including epithelial barriers, monocytes, granulocytes, and NK cells recovers within weeks after transplantation. By contrast, adaptive immunity recovers much slower. B- and T-cell counts normalize during the first months after transplantation, but in particular, T-cell immunity may remain impaired for years. During the last decade, much of the underlying mechanisms have been identified. These insights may provide new therapies to accelerate recovery.

Invasive rhino-maxillary mucormycosis diagnosed before HSCT

We report a case of successful allogeneic hematopoietic stem cell transplantation (HSCT) with full myeloablative conditioning in a patient with pre-existing invasive mucormycosis. The mucormycosis involved the maxilla, the nasal septum, and the hard palate. Sustained antifungal therapy and aggressive surgery both before and after HSCT were required.

Fungal Infections

The incidence of invasive fungal infections has increased dramatically over the past two decades, mostly due to an increase in the number of immunocompromised patients.1–4 Patients who undergo chemotherapy for a variety of diseases, patients with organ transplants, and patients with the acquired immune deficiency syndrome have contributed most to the increase in fungal infections.5 The actual incidence of invasive fungal infections in transplant patients ranges from 15% to 25% in bone marrow transplant recipients to 5% to 42% in solid organ transplant recipients.6,7 The most frequently encountered are Aspergillus species, followed by Cryptococcus and Candida species. Fungal infections are also associated with a higher mortality than either bacterial or viral infections in these patient populations. This is because of the limited number of available therapies, dose-limiting toxicities of the antifungal drugs, fewer symptoms due to lack of inflammatory response, and the lack of sensitive tests to aid in the diagnosis of invasive fungal infections.1 A study of patients with fungal infections admitted to a university-affiliated hospital indicated that community-acquired infections are becoming a serious problem; 67% of the 140 patients had community-acquired fungal pneumonia.8

Primary invasive aspergillosis of the digestive tract: report of two cases and review of the literature

Background:

Disseminated aspergillosis is thought to occur as a result of vascular invasion from the lungs with subsequent bloodstream dissemination, and portals of entry other than sinuses and/or the respiratory tract remain speculative.

Methods:

We report two cases of primary aspergillosis in the digestive tract and present a detailed review of eight of the 23 previously-published cases for which detailed data are available.

Results and Conclusion:

These ten cases presented with symptoms suggestive of typhlitis, with further peritonitis requiring laparotomy and small bowel segmental resection. All cases were characterized by the absence of pulmonary disease at the time of histologically-confirmed gastrointestinal involvement with vascular invasion by branched Aspergillus hyphae. These cases suggest that the digestive tract may represent a portal of entry for Aspergillus species in immunocompromised patients.

Human polymorphonuclear leukocytes inhibit Aspergillus fumigatus conidial growth by lactoferrin-mediated iron depletion

Aspergillus fumigatus, a common mold, rarely infects humans, except during prolonged neutropenia or in cases of chronic granulomatous disease (CGD), a primary immunodeficiency caused by mutations in the NADPH oxidase that normally produces fungicidal reactive oxygen species. Filamentous hyphae of Aspergillus are killed by normal, but not CGD polymorphonuclear leukocytes (PMN); however, the few studies on PMN-mediated host defenses against infectious conidia (spores) of this organism have yielded conflicting results, some showing that PMN do not inhibit conidial growth, with others showing that they do, most likely using reactive oxygen species. Given that CGD patients are exposed daily to hundreds of viable A. fumigatus conidia, yet considerable numbers of them survive years without infection, we reasoned that PMN use ROS-independent mechanisms to combat Aspergillus. We show that human PMN from both normal controls and CGD patients are equipotent at arresting the growth of Aspergillus conidia in vitro, indicating the presence of a reactive oxygen species-independent factor(s). Cell-free supernatants of degranulated normal and CGD neutrophils both suppressed fungal growth and were found to be rich in lactoferrin, an abundant PMN secondary granule protein. Purified iron-poor lactoferrin at concentrations occurring in PMN supernatants (and reported in human mucosal secretions in vivo) decreased fungal growth, whereas saturation of lactoferrin or PMN supernatants with iron, or testing in the presence of excess iron in the form of ferritin, completely abolished activity against conidia. These results demonstrate that PMN lactoferrin sequestration of iron is important for host defense against Aspergillus.

Antifungal prophylaxis for invasive mycoses in high risk patients

PURPOSE OF REVIEW

New broader spectrum antifungal agents with favorable safety profiles have been available for the last 15 years making prophylaxis feasible. The purpose of this article is to review recent studies in patient populations at high risk for invasive fungal infections.

RECENT FINDINGS

Itraconazole, lipid formulations of amphotericin B, posaconazole, caspofungin and micafungin have been utilized for prophylaxis in different immunocompromised host settings. Itraconazole and caspofungin remain an option especially in patients with hematological diseases. Low dose liposomal amphotericin B shows a lower morbidity rate in patients treated for acute myeloid leukemia. Posaconazole demonstrated survival benefits in this setting although data have only been presented at an international meeting. In the transplantation setting, micafungin was superior to fluconazole during the early neutropenic phase and posaconazole was superior to fluconazole in preventing invasive aspergillosis in hematopoietic transplant recipients treated for graft-versus-host disease. Results from the latter study have thus far only been presented in abstract form.

SUMMARY

Prophylaxis should only be given to a high-risk population. Results of studies should demonstrate morbidity and mortality advantages. The new generation of azoles and echinocandins have a favorable safety and drug interaction profile and appear advantageous in specific settings of immunosuppression. Pending full publication, posaconazole appears to be an appropriate agent for prophylaxis in acute myeloid leukemia patients or patients treated for graft-versus-host disease. Micafungin is superior to fluconazole in the neutropenic phase of hematopoietic transplantation.

Posaconazole or fluconazole for prophylaxis in severe graft-versus-host disease

BACKGROUND

Invasive fungal infections are an important cause of morbidity and mortality after allogeneic hematopoietic stem-cell transplantation.

METHODS

In an international, randomized, double-blind trial, we compared oral posaconazole with oral fluconazole for prophylaxis against invasive fungal infections in patients with graft-versus-host disease (GVHD) who were receiving immunosuppressive therapy. The primary end point was the incidence of proven or probable invasive fungal infections from randomization to day 112 of the fixed treatment period of the study.

RESULTS

Of a total of 600 patients, 301 were assigned to posaconazole and 299 to fluconazole. At the end of the fixed 112-day treatment period, posaconazole was found to be as effective as fluconazole in preventing all invasive fungal infections (incidence, 5.3% and 9.0%, respectively; odds ratio, 0.56; 95 percent confidence interval [CI], 0.30 to 1.07; P=0.07) and was superior to fluconazole in preventing proven or probable invasive aspergillosis (2.3% vs. 7.0%; odds ratio, 0.31; 95% CI, 0.13 to 0.75; P=0.006). While patients were receiving study medications (exposure period), in the posaconazole group, as compared with the fluconazole group, there were fewer breakthrough invasive fungal infections (2.4% vs. 7.6%, P=0.004), particularly invasive aspergillosis (1.0% vs. 5.9%, P=0.001). Overall mortality was similar in the two groups, but the number of deaths from invasive fungal infections was lower in the posaconazole group (1%, vs. 4% in the fluconazole group; P=0.046). The incidence of treatment-related adverse events was similar in the two groups (36% in the posaconazole group and 38% in the fluconazole group), and the rates of treatment-related serious adverse events were 13% and 10%, respectively.

CONCLUSIONS

Posaconazole was similar to fluconazole for prophylaxis against fungal infections among patients with GVHD. It was superior in preventing invasive aspergillosis and reducing the rate of deaths related to fungal infections. (ClinicalTrials.gov number, NCT00034645 [ClinicalTrials.gov].).

Nosocomial fungal infections: epidemiology, diagnosis, and treatment

Invasive fungal infections are increasingly common in the nosocomial setting. Furthermore, because risk factors for these infections continue to increase in frequency, it is likely that nosocomial fungal infections will continue to increase in frequency in the coming decades. The predominant nosocomial fungal pathogens include Candida spp., Aspergillus spp., Mucorales, Fusarium spp., and other molds, including Scedosporium spp. These infections are difficult to diagnose and cause high morbidity and mortality despite antifungal therapy. Early initiation of effective antifungal therapy and reversal of underlying host defects remain the cornerstones of treatment for nosocomial fungal infections. In recent years, new antifungal agents have become available, resulting in a change in standard of care for many of these infections. Nevertheless, the mortality of nosocomial fungal infections remains high, and new therapeutic and preventative strategies are needed.

Human pharmacogenomic variations and their implications for antifungal efficacy

Pharmacogenomics is defined as the study of the impacts of heritable traits on pharmacology and toxicology. Candidate genes with potential pharmacogenomic importance include drug transporters involved in absorption and excretion, phase I enzymes (e.g., cytochrome P450-dependent mixed-function oxidases) and phase II enzymes (e.g., glucuronosyltransferases) contributing to metabolism, and those molecules (e.g., albumin, A1-acid glycoprotein, and lipoproteins) involved in the distribution of antifungal compounds. By using the tools of population genetics to define interindividual differences in drug absorption, distribution, metabolism, and excretion, pharmacogenomic models for genetic variations in antifungal pharmacokinetics can be derived. Pharmacogenomic factors may become especially important in the treatment of immunocompromised patients or those with persistent or refractory mycoses that cannot be explained by elevated MICs and where rational dosage optimization of the antifungal agent may be particularly critical. Pharmacogenomics has the potential to shift the paradigm of therapy and to improve the selection of antifungal compounds and adjustment of dosage based upon individual variations in drug absorption, metabolism, and excretion.

In vitro and in vivo activities of HQQ-3, a new triazole antifungal agent

The activity of HQQ-3, a new triazole antifungal agent, was evaluated and compared with those of fluconazole, ketoconazole and terbinafine in vitro and with fluconazole in vivo. HQQ-3 exhibited potent in vitro activity against clinically important fungi. The activity of HQQ-3 against Candida spp. was superior to those of fluconazole and terbinafine and comparable or superior to that of ketoconazole. HQQ-3 retained potent activity against Candida albicans strains with low levels of susceptibility to fluconazole (fluconazole MIC80s range, 4 to >64 microg/ml). Against Cryptococcus neoformans and filamentous fungi, the activity of HQQ-3 was superior to that of fluconazole. HQQ-3 also exhibited potent in vivo activity against murine systemic infections caused by C. albicns and C. krusei. The 50% effective doses against these infections were 0.12 to 1.9 mg/kg of body weight. These result suggest that HQQ-3 may be useful in the treatment of candidiasis.

Critical care considerations of hematopoietic stem cell transplantation

OBJECTIVE

To review the available clinical data on the critical care complications of hematopoietic stem cell transplantation (HSCT).

DATA SOURCE

The MEDLINE database and references from the identified articles related to the critical care in HSCT.

CONCLUSION

HSCT is an important treatment for a variety of malignant and nonmalignant conditions. The procedure is, however, limited by significant complications that may involve every organ of the body. Up to 40% of HSCT recipients are admitted to the intensive care unit as a result of severe complications related to the transplantation. The outcome of those critically ill patients has been traditionally poor. However, recent advances in the transplantation procedure, diagnostic studies, antimicrobial prophylaxis and therapy, and intensive care unit care have improved the outcome of these patients. The increasing number of HSCTs performed annually, the unique complications that develop in these patients, and the improvement in the intensive care unit outcome make knowledge about the critical care aspect of HSCT an essential part of the current practice of critical care medicine.

Caspofungin and liposomal amphotericin B therapy of experimental murine scedosporiosis

Immunosuppressed mice were infected intravenously with conidia of Scedosporium prolificans. Treatment was begun 1 day later with liposomal amphotericin B, caspofungin, or both drugs initiated concurrently. Amphotericin B and caspofungin were each effective, but combined therapy did not appear to offer advantages over liposomal amphotericin B alone.

Non-comparative evaluation of the safety of aerosolized amphotericin B lipid complex in patients undergoing allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplant (HSCT) recipients are at increased risk for invasive fungal infections (IFIs) over prolonged periods of time. Aerosolized amphotericin B lipid complex (ABLC) has shown promise in lung transplant recipients as a convenient means of delivering protective drug to the upper airways avoiding systemic toxicities. The safety and tolerability of aerosolized ABLC in 40 subjects undergoing allogeneic HSCT was prospectively investigated in an open-labeled, non-comparative study. Subjects received aerosolized ABLC treatment once daily for 4 days, then once weekly for 13 weeks; fluconazole was administered daily as standard of care through post-transplant day 100. Pulmonary mechanics were measured before and after each dose of inhaled ABLC; adverse events (AEs) and the development of IFI were also monitored. Cough, nausea, taste disturbance, or vomiting followed 2.2% of 458 total inhaled ABLC administrations; 5.2% of inhaled ABLC administrations were associated with >or=20% decrease in pulmonary function measurements (forced expiratory volume in 1 second or forced vital capacity) and none required treatment with bronchodilators or withdrawal from study. Four mild AEs were considered possibly or probably related to study treatment; no deaths or withdrawals from treatment were attributed to study drug. Of 3 proven IFIs occurring during the study period, only 1, a catheter-related case of disseminated fusariosis, occurred while the subject was receiving study medication. Aerosolized ABLC was well tolerated in allogeneic HSCT recipients. With only 1 of 40 subjects developing IFI while receiving treatment, the combination of fluconazole and inhaled ABLC warrants further study as antifungal prophylaxis following allogeneic HSCT.

Candida-Associated Denture Stomatitis in Patients After Immunosuppression Therapy

Patients who undergo kidney or liver transplantation receive long-lasting immunosuppressive therapy. The resultant unfavorable symptoms result from immune deficiency and the side effects of the medications. The aim of this study was to establish the frequency and intensity of denture stomatitis and oral candidiasis among denture-wearing patients who were treated with immunosuppressive drugs. The study was performed in the group of denture wearers with a transplanted kidney or liver who had been treated with immunosuppressive medications. The control group included healthy people wearing dentures. We made physical and clinical examinations in both groups. The history covered nonobjective symptoms in the oral cavity, hygienic habits in the mouth, and the time span during which the dentures had been used. We also evaluated the conditions of the oral mucosal membrane, angular cheilitis, as well as denture stabilization. In both groups mycological investigations were performed by inoculating a direct swab from the oral mucosa and the denture surface on Soborauda agar. The results of our study suggest that patients with immunosuppression were more frequently subject to Candida albicans infections and stomatitis.

Non-Aspergillus Fungal Pneumonia in Transplant Recipients

Although species of Aspergillus and Candida account for most deeply invasive and life-threatening fungal infections, the past decades have seen a rise in the immunocompromised population. With this increase, additional fungi have emerged as important agents of morbidity and mortality. These opportunistic fungi are characterized by their ubiquitous presence in the environment, their ability to cause disease in immunosuppressed patients, and their diminished susceptibility to the currently available antifungal agents. Pneumonia, one aspect of a myriad of clinical manifestations caused by these fungal pathogens, is discussed in this article.

Primary cutaneous opportunistic mold infections in a pediatric population

OBJECTIVE

We sought to describe the features of cutaneous opportunistic mold infections in a general pediatric population.

METHODS

Computerized pathology records from Texas Children's Hospital in Houston during the years 1991 to 2000 were used to identify any biopsy specimens of skin diagnosed as having fungus or mold. The corresponding medical records were reviewed to identify cases of cutaneous opportunistic mold infections. Cases were limited to those with histologic confirmation of hyphae within the dermis or extending to the dermis.

RESULTS

A total of 11 cases in neonates and 22 cases in children and adolescents were identified. Prematurity and low birth weight were the major risk factors in the neonatal population. The nonneonatal cases mainly occurred in those with malignancies or undergoing transplantation. Mortality in neonates was 64%, but decreased to 18% in the nonneonatal population.

CONCLUSION

Our overview of cutaneous infection by opportunistic molds in a pediatric population highlights the risk factors, causative organisms, and outcome of this group of infections. Even in the presence of severe compromise of the immune system, children with primary cutaneous mold infections had a favorable outcome with appropriate diagnosis and therapy.

Workload due to Aspergillus fumigatus and significance of the organism in the microbiology laboratory of a general hospital

The increase in the immunocompromised population and the incidence of invasive aspergillosis (IA) are leading to an overinterpretation of the potential clinical significance of many isolates of Aspergillus fumigatus. Our work prospectively assesses the workload of the isolation of A. fumigatus and its clinical significance in the microbiology laboratory of a large teaching hospital. During a 3-year period, all patients from whom A. fumigatus was isolated were prospectively monitored and classified as having IA or "nonsignificant" disease. A point score based on the prediction of five easily obtained laboratory and clinical parameters was applied. We found 404 A. fumigatus isolates in 260 patients (1/1,000 microbiology laboratory samples; 2.1 patients/10,000 admissions). A total of 90 isolates (22.3%) were from patients with IA. Of the 260 patients, 31 (12%) had invasive disease (IA), and the remaining 229 had "nonsignificant" disease. A score based on points for five parameters was applied to our population. It was constructed as follows: "sample obtained by invasive procedures" (1 point), "presence of two or more positive samples from the same patient" (1 point), "leukemia" (2 points), "neutropenia" (5 points), and "corticosteroid treatment" (2 points). Patients with a score of 0 had only a 2.5% probability of IA. Those with a score of 1 or 2 had an increased probability of 10.3%. The probabilities rose to 40% and 70%, respectively, for patients with a score of 3 or 4 or a score of > or = 5. A simple score based on five easily available parameters may be of help to microbiologists and clinicians to predict the risk of IA.

Aspergillus infections in transplant recipients

Aspergillus infections are occurring with an increasing frequency in transplant recipients. Notable changes in the epidemiologic characteristics of this infection have occurred; these include a change in risk factors and later onset of infection. Management of invasive aspergillosis continues to be challenging, and the mortality rate, despite the use of newer antifungal agents, remains unacceptably high. Performing molecular studies to discern new targets for antifungal activity, identifying signaling pathways that may be amenable to immunologic interventions, assessing combination regimens of antifungal agents or combining antifungal agents with modulation of the host defense mechanisms, and devising diagnostic assays that can rapidly and reliably diagnose infections represent areas for future investigations that may lead to further improvement in outcomes.

In Vitro Antifungal Activity of ZJ-522, a New Triazole Restructured from Fluconazole and Butenafine, against Clinically Important Fungi in Comparison with Fluconazole and Butenafine

The antifungal activity of ZJ-522, a new triazole antifungal agent restructured from fluconazole and butenafine, was compared to that of fluconazole and butenafine against 43 strains of fungi representing 13 fungal species. MICs were determined by using the National Committee for Clinical Laboratory Standards (NCCLS)-recommended broth microdilution method for yeasts, which was modified for filamentous fungi. ZJ-522 was about 50-fold and 2 to 16-fold more potent than fluconazole against yeasts and filamentous fungi respectively, but it was less active than butenafine against filamentous fungi, although butenafine was inactive against most yeasts. Thus, the fashion of ZJ-522 antifungal activity more similar to that of fluconazole than that of butenafine indicates that ZJ-522 should be an inhibitor of lanosterol 14alpha-demethylase but not of squalene epoxidase, and should be a candidate for clinical development.

Candidaemia in allogeneic stem cell transplant recipients: low risk without fluconazole prophylaxis

Invasive fungal infections (IFI) are common in allogeneic SCT recipients. We have reviewed our experience of IFI with special reference to candidaemia in 685 adult patients transplanted in 1983-2002. The donor was a matched sibling in 505 patients and an unrelated donor in 180 patients. A BM graft was used in 561 patients and a PB graft in 124 patients. Fluconazole prophylaxis was not used during the study period. Definite or probable IFI was observed in 60 patients (8.7%) with a dominance of Aspergillus infections (46 patients, incidence 6.7%). Candidaemia was found only in nine patients (1.3%). The causative agents were Candida albicans (n=8), C. krusei (n=2), and C. glabrata (n=1); in two patients, two causative agents were found. The median time to the diagnosis of candidaemia was 53 days (range 6-249 days) post transplant. Seven patients were neutropaenic at diagnosis, and four patients had experienced acute GVHD. All patients received antifungal therapy, but only one patient was cured. According to this study, candidaemia was a rare event in allogeneic SCT recipients. Thus, systematic prophylaxis against Candida infections might not be indicated. The prognosis of established infections is still poor due to comorbid conditions, notably GVHD.

Kinetics of myeloid and lymphocyte recovery and infectious complications after unrelated umbilical cord blood versus HLA-matched unrelated donor allogeneic transplantation in adults

Sources for allogeneic stem cells for patients with haematological disorders lacking a histocompatible sibling donor include matched unrelated donor (MUD) and umbilical cord blood (UCB). A total of 51 patients with haematological disorders, treated with myeloablation and transplantation with either unrelated human leucocyte antigen (HLA) partially matched UCB (28 patients) or HLA-matched MUD grafts (23 patients) during 1997-2003, were evaluated for life-threatening infections, haematological reconstitution, graft versus host disease, relapse and event-free survival (EFS). The median duration of neutropenia after transplantation was longer (29 d vs. 14 d) in the UCB group. The probability of donor-derived neutrophil engraftment by day 42 was 0.86 [95% confidence interval (CI) 0.71-1.0] in UCB recipients versus 0.96 (95% CI 0.87-1.0) in MUD recipients surviving >28 d. Overall infection rates were higher in UCB recipients, particularly at the early time points (before day +50) after transplantation. Graft failure occurred in five UCB recipients and two MUD recipients and was associated with the occurrence of bacteraemia during neutropenia. The EFS at 3-year follow-up was 0.25 in UCB and 0.35 in MUD recipients. UCB transplantation in adults is associated with delayed neutrophil and lymphocyte recovery compared with MUD grafting, and higher rates of bacteraemia at early time points after transplantation.

Glucocorticoids and invasive fungal infections

Since the 1990s, opportunistic fungal infections have emerged as a substantial cause of morbidity and mortality in profoundly immunocompromised patients. Hypercortisolaemic patients, both those with endogenous Cushing's syndrome and, much more frequently, those receiving exogenous glucocorticoid therapy, are especially at risk of such infections. This vulnerability is attributed to the complex dysregulation of immunity caused by glucocorticoids. We critically review the spectrum and presentation of invasive fungal infections that arise in the setting of hypercortisolism, and the ways in which glucocorticoids contribute to their pathogenesis. A better knowledge of the interplay between glucocorticoid-induced immunosuppression and invasive fungal infections should assist in earlier recognition and treatment of such infections. Efforts to decrease the intensity of glucocorticoid therapy should help to improve outcomes of opportunistic fungal infections.

Infectious complications following allogeneic HLA-identical sibling transplantation with antithymocyte globulin-based reduced intensity preparative regimen

In the setting of reduced-intensity conditioning (RIC) regimens for allogeneic stem cell transplantation (allo-SCT), the epidemiology of transplant-related infections is still poorly defined. In 101 high-risk patients who received an HLA-identical sibling allo-SCT after RIC, including fludarabine, busulfan and antithymocyte globulin (ATG), we report during the first 6 months a cumulative incidence of positive CMV antigenemia of 42% (95% CI 32-52%), developing at a median of 37 (range 7-116) days without evidence of CMV disease (median follow-up, 434 days). The cumulative incidence of bacteremia was 25% (95% CI 17-33%), occurring at a median of 67 (range 7-172) days, while patients had recovered a full neutrophil count. In all, 65% of the bacteremia (95% CI 49-81%) were gram negative. The cumulative incidence of fungal infections was 8% (95% CI 3-13%), with a median onset of 89 (range 7-170) days. In multivariate analysis, stem cell source (bone marrow; P=0.0002) was significantly associated with the risk of positive CMV antigenemia, while higher doses of prednisone (>2 mg/kg) represented the major risk factor for bacteremia (P=0.0001). Infectious-related mortality was 5% (95% CI 1-9%), with aspergillosis being the principal cause. Collectively, these results suggest that prospective efforts are warranted to develop optimal antimicrobial preventive strategies after RIC allo-SCT.

Efficacy of granulocyte transfusions for neutropenia-related infections: retrospective analysis of predictive factors

BACKGROUND

The transfusion of G-CSf-primed granulocytes (GTX) might represent an important treatment option for neutropenia-related infections unresponsive to conventional antimicrobial therapies and to recombinant hematopoietic growth factors. However, few studies to date have identified the factors that can predict clinical outcome and the patient populations who are likely to benefit most from GTX. The primary endpoint of the present retrospective study was to evaluate the efficacy of GTX in 22 patients with hematological malignancies who developed neutropenia-related bacterial and fungal infections that were unresponsive to appropriate antimicrobial therapies.

METHODS

Peripheral blood granulocytes were collected by continuous-flow leukapheresis from HLA-identical siblings after priming with G-CSF. The response to GTX was classified as 'favorable' if clinical symptoms and signs of infection resolved or 'unfavorable' if clinical symptoms and signs of infection were unchanged or worsened. Control of infection at Day 30 after the enrollment in the GTX program was considered as the outcome variable in multiple regression analysis.

RESULTS

Two patients died of infection before receiving the granulocyte concentrates. Bacterial infections (monomicrobial or mixed bacteremias) were documented in 11 patients, whereas fungal infections (fungemia or focal fungal infections) were diagnosed in seven patients. In two patients, no infecting agent could be isolated (clinical infection). Control of infection at Day 30 after the first GTX was achieved in 10 of 20 assemble patients. Overall, 54% of patients with bacterial infections had a favorable response, compared with 57% of patients with fungal infections. No differences in terms of survival were found when comparing patients with bacterial and those with fungal infections at a median follow-up 90 days from the first GTX. In univariate analysis, disease status before GTX, e.g., complete or partial remission, and spontaneous recovery of the neutrophil count were significantly associated with control of infection. when multivariate regression models were formed, the recovery 0.5 x 10 (9)/L PMN was the only parameter that significantly and independently correlated with a favorable response to GTX.

DISCUSSION

GTX can be used to successfully treat bacterial as well as fungal infections in severely neutropenic patients when administered early after the onset of febrile neutropenia in patients with remission of the underlying disease and who are likely to recover marrow function.

Early reconstitution of the T-cell repertoire after non-myeloablative peripheral blood stem cell transplantation is from post-thymic T-cell expansion and is unaffected by graft-versus-host disease or mixed chimaerism

To study immune recovery after non-myeloablative, reduced-intensity stem cell allografts (NST) and T-cell-depleted myeloablative transplants (TCD), we measured T-cell subset recovery by flow cytometry, T-cell repertoire by spectratyping and thymic T-cell output using a T-cell receptor excision circle (TREC) assay. We found a rapid and comparable increase in lymphocyte numbers in both NST and TCD, supporting the presence of a powerful drive for lymphocyte recovery after transplant. Spectratyping on d 45 and 100 revealed almost complete normalization of the T-cell repertoire in NST patients by d 45, whereas TCD patients demonstrated marked skewing of the repertoire, persisting to d 100. After NST, there was a significantly higher number of TREC-positive CD4+ and CD8+ cells (P = 0.02 and P = 0.01 respectively). However, in both NST and TCD, early T-cell recovery after transplant appeared to result entirely from post-thymic T cells, the expansion pattern of which is most influenced by the starting T-cell dose, but not markedly by graft-versus-host disease (GVHD) or mixed chimaerism. These results define important qualitative differences in the T-cell repertoire according to the type of transplant schedule used.

Risks and outcomes of invasive fungal infections in recipients of allogeneic hematopoietic stem cell transplants after nonmyeloablative conditioning

The incidence of invasive mold infections has increased during the 1990s among patients undergoing allogeneic hematopoietic stem cell transplantation (HCT) after myeloablative conditioning. In this study, we determined risk factors for invasive mold infection and mold infection-related death among 163 patients undergoing allogeneic HCT with nonmyeloablative conditioning. The cumulative incidence rates of proven or probable invasive fungal infections, invasive mold infections, invasive aspergillosis, and invasive candidiasis during the first year after allogeneic HCT with nonmyeloablative conditioning were 19%, 15%, 14%, and 5%, respectively, which were similar to those after conventional myeloablative HCT. Invasive mold infections occurred late after nonmyeloablative conditioning (median, day 107), with primary risk factors including severe acute graft-versus-host disease (GVHD), chronic extensive GVHD, and cytomegalovirus (CMV) disease. The 1-year survival after diagnosis of mold infections was 32%. High-dose corticosteroid therapy at diagnosis of mold infection was associated with an increased risk for mold infection-related death. Overall, nonrelapse mortality was estimated at 22% (36 patients) after nonmyeloablative conditioning, of which 39% (14 patients) were mold infection-related (9% of the overall mortality). More effective strategies are needed to prevent invasive mold infections, which currently account for a notable proportion of nonrelapse mortality after nonmyeloablative allogeneic HCT.

Genetic diversity among clinical isolates of Acremonium strictum determined during an investigation of a fatal mycosis

Primarily saprophytic in nature, fungi of the genus Acremonium are a well-documented cause of mycetoma and other focal diseases. More recently, a number of Acremonium spp. have been implicated in invasive infections in the setting of severe immunosuppression. During the course of routine microbiological studies involving a case of fatal mycosis in a nonmyeloablative hematopoietic stem cell transplant patient, we identified a greater-than-expected variation among strains previously identified as Acremonium strictum by clinical microbiologists. Using DNA sequence analysis of the ribosomal DNA intergenic transcribed spacer (ITS) regions and the D1-D2 variable domain of the 28S ribosomal DNA gene (28S), the case isolate and four other clinical isolates phenotypically identified as A. strictum were found to have <99% homology to the A. strictum type strain, CBS 346.70, at the ITS and 28S loci, while a sixth isolate phenotypically identified only as Acremonium sp. had >99% homology to the type strain at both loci. These results suggest that five out of the six clinical isolates belong to species other than A. strictum or that the A. strictum taxon is genetically diverse. Based upon these sequence data, the clinical isolates were placed into three genogroups.