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

Development of a LightCycler PCR assay for detection and quantification of Aspergillus fumigatus DNA in clinical samples from neutropenic patients

The increasing incidence of invasive aspergillosis, a life-threatening infection in immunocompromised patients, emphasizes the need to improve the diagnostic tools for this disease. We established a LightCycler-based real-time PCR assay to detect and quantify rapidly, specifically, and sensitively Aspergillus fumigatus DNA in both bronchoalveolar lavage (BAL) and blood samples from high-risk patients. The primers and hybridization probes were derived from an A. fumigatus-specific sequence of the mitochondrial cytochrome b gene. The assay is linear in the range between 13.2 fg and 1.3 ng of A. fumigatus DNA, corresponding to 3 to 300,000 CFU per ml of BAL fluid or blood. No cross-amplification was observed with human DNA or with the DNA of fungal or bacterial pathogens. For clinical evaluation we investigated 10 BAL samples from nine neutropenic patients with malignant hematological diseases and 12 blood samples from seven neutropenic patients with malignant hematological diseases. Additionally, we tested one blood sample and one BAL sample from each of two neutropenic patients. In order to characterize the validity of the novel PCR assay, only samples that had shown positive results by a previously described sensitive and specific nested PCR assay were tested. Twelve of 12 BAL samples and 6 of 14 blood samples gave positive results by the LightCycler PCR assay. Eight of 14 blood samples gave negative results by the novel method. The LightCycler PCR-mediated quantification of the fungal burden showed 15 to 269,018 CFU per ml of BAL sample and 298 to 104,114 CFU per ml of blood sample. Twenty of 20 BAL samples and 50 of 50 blood samples from subjects without evidence of invasive pulmonary aspergillosis (IPA) were PCR negative. Compared to a previously described nested PCR assay, these preliminary data for the novel real-time PCR assay indicate a less sensitive rate of detection of IPA in high-risk patients, but the assay may be valuable for quantification of the fungal burden in individual clinical samples.

Invasive aspergillosis in allogeneic stem cell transplant recipients: changes in epidemiology and risk factors

The incidence of postengraftment invasive aspergillosis (IA) in hematopoietic stem cell transplant (HSCT) recipients increased during the 1990s. We determined risks for IA and outcomes among 1682 patients who received HSCTs between January 1993 and December 1998. Risk factors included host variables (age, underlying disease), transplant variables (stem cell source), and late complications (acute and chronic graft-versus-host disease [GVHD], receipt of corticosteroids, secondary neutropenia, cytomegalovirus [CMV] disease, and respiratory virus infection). We identified risk factors associated with IA early after transplantation (<or= 40 days) and after engraftment (41-180 days). Older patient age was associated with an increased risk during both periods. Chronic myelogenous leukemia (CML) in chronic phase was associated with low risk for early IA compared with other hematologic malignancies, aplastic anemia, and myelodysplastic syndrome. Multiple myeloma was associated with an increased risk for postengraftment IA. Use of human leukocyte antigen (HLA)-matched related (MR) peripheral blood stem cells conferred protection against early IA compared with use of MR bone marrow, but use of cord blood increased the risk of IA early after transplantation. Factors that increased risks for IA after engraftment included receipt of T cell-depleted or CD34-selected stem cell products, receipt of corticosteroids, neutropenia, lymphopenia, GVHD, CMV disease, and respiratory virus infections. Very late IA (> 6 months after transplantation) was associated with chronic GVHD and CMV disease. These results emphasize the postengraftment timing of IA; risk factor analyses verify previously recognized risk factors (GVHD, receipt of corticosteroids, and neutropenia) and uncover the roles of lymphopenia and viral infections in increasing the incidence of postengraftment IA in the 1990s.

Aspergillus infections in allogeneic stem cell transplant recipients: have we made any progress?

Invasive aspergillosis (IA) is common in allogeneic SCT recipients, with an incidence of 4-10%. The majority of these infections are diagnosed several months after SCT and they are frequently associated with GVHD. The diagnosis is difficult and often delayed. Established IA is notoriously difficult to treat with a death rate of 80-90%. This review summarises recent data on this problem to assess whether there has been any progress. Effective prophylactic measures are still lacking. Severe immunosuppression is the main obstacle to the success of therapy. Recent and ongoing developments in diagnostic measures and new antifungal agents may improve treatment results to some extent, but Aspergillus infections still remain a formidable problem in allogeneic transplantation. Further studies in this field will focus on the role of various cytokines and combinations of antifungal agents.

Invasive infection due to penicillium species other than P. marneffei

Infection caused by Penicillium spp. due to species other than P. marneffei is rare. We present three such cases of invasive disease. The first had chronic granulomatous disorder (CGD) with pulmonary infection caused by Penicillium spp. and he responded to amphotericin B therapy. Cases two and three were not known to be immunocompromised and both failed to respond to therapy. Case two had cerebral disease from an unknown source caused by P. chrysogenum. Case three probably acquired infection caused by P. decumbens peri-operatively and presented with paravertebral infection. The pertinent literature on invasive infections of Penicillium spp. other than P. marneffei is reviewed. From 1951 onwards, 31 reported cases of invasive disease included 12 cases of pulmonary infection (six in non-immunocompromised patients), four cases of prosthetic valve endocarditis, six cases of CAPD peritonitis, five cases of endophthalmitis, individual cases of fungemia and oesophagitis (both in AIDS), upper urinary tract infection and intracranial infection. Trauma, surgery or prosthetic material is commonly implicated in the non-pulmonary cases. Superficial infection (keratitis and otomycosis) is commonly caused by Penicillium spp. Allergic pulmonary disease, often occupational (such as various cheeseworkers' diseases), is also common. Optimal therapy for invasive infection is not established, but surgery may be advisable if possible. Amphotericin B may be the most effective antifungal drug.

Fungal infections in marrow transplant recipients under antifungal prophylaxis with fluconazole

Fungal infection is one of the most important causes of morbidity and mortality in bone marrow transplant (BMT) recipients. The growing incidence of these infections is related to several factors including prolonged granulocytopenia, use of broad-spectrum antibiotics, conditioning regimens, and use of immunosuppression to avoid graft-versus-host disease (GvHD). In the present series, we report five cases of invasive mold infections documented among 64 BMT recipients undergoing fluconazole antifungal prophylaxis: 1) A strain of Scedosporium prolificans was isolated from a skin lesion that developed on day +72 after BMT in a chronic myeloid leukemic patient. 2) Invasive pulmonary aspergillosis (Aspergillus fumigatus) was diagnosed on day +29 in a patient with a long period of hospitalization before being transplanted for severe aplastic anemia. 3) A tumoral lung lesion due to Rhizopus arrhizus (zygomycosis) was observed in a transplanted patient who presented severe chronic GvHD. 4) A tumoral lesion due to Aspergillus spp involving the 7th, 8th and 9th right ribs and local soft tissue was diagnosed in a BMT patient on day +110. 5) A patient with a history of Ph1-positive acute lymphocytic leukemia exhibited a cerebral lesion on day +477 after receiving a BMT during an episode of severe chronic GvHD. At that time, blood and spinal fluid cultures yielded Fusarium sp. Opportunistic infections due to fungi other than Candida spp are becoming a major problem among BMT patients receiving systemic antifungal prophylaxis with fluconazole.

Fungicidal activities of commonly used disinfectants and antifungal pharmaceutical spray preparations against clinical strains of Aspergillus and Candida species

The antifungal efficacy of commercial chemical disinfectants and pharmaceutical antifungal agents against medically important moulds and yeast species was investigated. Chlorine, phenol, sodium dodecyl sulfate and quaternary ammonium salts were the chemical disinfectants, and bifonazole and terbinafine were the antifungal pharmaceutical products tested against clinical isolates of Aspergillus and Candida species. Fungal inocula were obtained from conidial preparations of two A. ochraceus strains and yeast cells of C. albicans, C. krusei and C. parapsilosis. The antifungal activities were evaluated either by determining the kill rate in a cell suspension media at different contact periods, or by examining the viability and growth on plates sprayed with the active ingredient. Chlorine (1%) was the only disinfectant with the ability to cause a rapid inactivation of all five strains. Phenol (5%) was equally effective against Candida species; however, a number of A. ochraceus conidia were able to survive this treatment for up to 1 h. Benzalkonium chloride (0.5%) and cetrimide (0.5%) were also able to disinfect the three Candida species rapidly; however, these two quaternary ammonium compounds were relatively ineffective against A. ochraceus. In spray experiments, quaternary ammonium compounds had a fungicidal activity against Candida species and were fungistatic against A. ochraceus conidia. All five fungal strains were able to resist 0.5% sodium dodecyl sulfate, present either in the suspension solution or on the sprayed plate. Of the two pharmaceutical antifungal products tested, bifonazole (1%) were essentially ineffective against all five strains. Terbinafine (1%) had a fungicidal activity against A. ochraceus and C. parapsilosis. In suspension experiments, an exposure to 0.01% terbinafine required a contact period of 1 h for a complete inactivation of A. ochraceus conidia and an onset of fungicidal effect on C. parapsilosis yeast cells. Terbinafine was only moderately effective against C. albicans and was completely ineffective against C. krusei.

Fluconazole to prevent yeast infections in bone marrow transplantation patients: a randomized trial of high versus reduced dose, and determination of the value of maintenance therapy

PURPOSE

To determine the optimal dose and duration of fluconazole antifungal prophylaxis therapy in bone marrow transplantation patients.

SUBJECTS AND METHODS

Two hundred and fifty-three pediatric and adult bone marrow transplantation patients were randomly assigned to receive fluconazole 400 mg daily (high dose) or 200 mg daily (low dose) while they were neutropenic. After neutrophil recovery, patients were randomly assigned to receive maintenance therapy with either fluconazole (100 mg daily) or clotrimazole troches (10 mg 4 times daily) until 100 days after transplantation. Patients were monitored until 2 weeks after completion of early prophylaxis and to 100 days after transplantation.

RESULTS

During the early prophylaxis phase, rates of yeast colonization and infections were similar in both treatment groups. By day 50, the incidence of Candida infections in the high-dose group was 4% (95% confidence interval [CI]: 1% to 7%; n = 5), compared with 1% in the low-dose fluconazole group (95% CI: 0% to 3%; n = 1; P = 0.08). During the same period, the incidence of Aspergillus infections was 4% (95% CI: 1% to 7%; n = 5) in the high-dose group and 2% (95% CI: 0% to 4%; n = 2; P = 0.33) in the low-dose group. During the maintenance prophylaxis phase, rates of yeast colonization and superficial infections were similar in the fluconazole and clotrimazole groups. Four patients developed systemic fungal infection in the maintenance phase (1 who received clotrimazole and 3 who received fluconazole).

CONCLUSION

High-dose (400 mg daily) and low-dose (200 mg daily) fluconazole have similar efficacy in reducing the incidence of yeast colonization, superficial infection, and systemic infection in neutropenic pediatric and adult patients undergoing bone marrow transplantation. Rates of yeast colonization after neutrophil recovery were similar in patients treated with fluconazole or clotrimazole.

Epidemiology and outcome of mould infections in hematopoietic stem cell transplant recipients

Reports have focused on the emergence of moulds as pathogens in recipients of hematopoietic stem cell transplants. To review the incidence of and risks for mould infections, we examined the records of 5589 patients who underwent hematopoietic stem cell transplantation at the Fred Hutchinson Cancer Research Center (Seattle) from 1985 through 1999. After 1992, the incidence of invasive aspergillosis increased in allograft recipients and remained high through the 1990s. Infections with non-fumigatus Aspergillus species, Fusarium species, and Zygomycetes increased during the late 1990s, especially in patients who received multiple transplants. Although infection caused by Scedosporium species was common in patients who had neutropenia, infection caused by Zygomycetes typically occurred later after transplantation, when patients had graft-versus-host disease. The overall 1-year survival rate was equally poor (similar20%) for all patients with mould infections. The results of the present study demonstrate the changing epidemiology of mould infections, emphasizing the increasing importance of amphotericin B--resistant organisms and the differences in risks and outcome of infection with different filamentous fungi.

Clinical evaluation of a polymerase chain reaction assay to detect Aspergillus species in bronchoalveolar lavage samples of neutropenic patients

The increasing incidence of invasive aspergillosis, a life-threatening infection in immunocompromised patients, emphasizes the need to improve the currently limited diagnostic tools. Using a recently developed two-step polymerase chain reaction (PCR) assay to detect 10 fg of Aspergillus DNA, corresponding to 1-5 colony-forming units (CFU)/ml of spiked samples in vitro, we prospectively examined 197 bronchoalveolar lavage (BAL) samples from 176 subjects, including 141 neutropenic, febrile patients with lung infiltrates, at risk for invasive fungal disease. Underlying diseases of these patients were haematological malignancies; 93 patients suffered from acute leukaemias. Thirty-one of these immunocompromised patients (17.6%) were PCR positive, correlating with positive BAL culture, positive histology from lung surgery or from autopsy, positive computerized tomography scans or positive galactomannan enzyme-linked immunosorbent assay. Six patients (4.3%) of this group had positive PCR results without any correlation to clinical or other diagnostic data, probably owing to contamination of the samples by ubiquitous Aspergillus spores. The samples of two patients (1.4%) with a subsequent histologically proven mould infection were PCR negative. All 102 immunocompromised patients (72.3%) with a negative PCR showed no evidence of invasive fungal disease. From 35 patients without immunodeficiency, four (11.4%) showed positive results, without evidence of invasive or non-invasive pulmonary aspergillosis. In this haematological population, the sensitivity and specificity values of the test reached 93.9% and 94.4%, the positive predictive value 83.8%, the negative predictive value 98.1%. Our data support the considerable clinical value of this PCR assay for confirming and improving diagnosis of pulmonary aspergillosis in high-risk patients.

Invasive fungal infections after allogeneic peripheral blood stem cell transplantation: incidence and risk factors in 395 patients

We have analysed the incidence and risk factors for the occurrence of invasive fungal infections (IFI) among 395 recipients of an allogeneic peripheral blood stem cell transplantation (PBSCT) from a human leucocyte antigen (HLA)-identical sibling. IFI (n = 50) occurred in 46 patients, giving an overall probability of 14%. There were 12 cases of invasive candidiasis (3%), with only one death. Non-Candida IFI occurred in 37 patients (12% probability), mostly invasive aspergillosis (n = 32). In multivariate analysis the only two significant variables associated with a higher risk of developing a non-Candida IFI were the development of moderate-to-severe graft-versus-host disease (GvHD, P < 0.0001; OR 4.6) and having received steroid prophylaxis for GvHD (P = 0.04; OR 2.1). In multivariate analysis the variables associated with a lower overall survival after PBSCT were development of a non-Candida IFI (P < 0.0001; OR 5.6), non-early disease phase (P = 0.0001; OR 1.9), steroid prophylaxis (P = 0.02; OR 1.4), moderate-to-severe GvHD (P = 0.01; OR 1.6) and cytomegalovirus infection post transplant (P = 0.001; OR 1.8). Our results show that non-Candida IFI (in particular aspergillosis) was an important cause of infectious morbidity and mortality after an HLA-identical sibling PBSCT, while invasive candidiasis was rare. Use of steroid prophylaxis and, in particular, the development of moderate-to-severe GvHD post transplant were risk factors for non-Candida IFI. Prophylactic strategies for these infections should thus take into account these risk factors.

Immunity of patients surviving 20 to 30 years after allogeneic or syngeneic bone marrow transplantation

The duration of immunodeficiency following marrow transplantation is not known. Questionnaires were used to study the infection rates in 72 patients surviving 20 to 30 years after marrow grafting. Furthermore, in 33 of the 72 patients and in 16 donors (siblings who originally donated the marrow) leukocyte subsets were assessed by flow cytometry. T-cell receptor excision circles (TRECs), markers of T cells generated de novo, were quantitated by real-time polymerase chain reaction. Immunoglobulin G(2) (IgG(2)) and antigen-specific IgG levels were determined by enzyme-linked immunosorbent assay. Infections diagnosed more than [corrected] 15 years after transplantation occurred rarely. The average rate was 0.07 infections per patient-year (one infection every 14 years), excluding respiratory tract infections, gastroenteritis, lip sores, and hepatitis C. The counts of circulating monocytes, natural killer cells, B cells, CD4 T cells, and CD8 T cells in the patients were not lower than in the donors. The counts of TREC(+) CD4 T cells in transplant recipients younger than age 18 years (at the time of transplantation) were not different from the counts in their donors. In contrast, the counts of TREC(+) CD4 T cells were lower in transplant recipients age 18 years or older, even in those with no history of clinical extensive chronic graft-versus-host disease, compared with their donors. The levels of total IgG(2) and specific IgG against Haemophilus influenzae and Streptococcus pneumoniae were similar in patients and donors. Overall, the immunity of patients surviving 20 to 30 years after transplantation is normal or near normal. Patients who received transplants in adulthood have a clinically insignificant deficiency of de novo-generated CD4 T cells, suggesting that in these patients the posttransplantation thymic insufficiency may not be fully reversible.

Epidemiology and Prevention of Invasive Aspergillosis

Aspergillus species are the most common causes of invasive mold infections in immunocompromised persons. This review examines the available information regarding the rising incidence of invasive aspergillosis in different high-risk groups, including persons with acute leukemia, hematopoietic stem cell transplant recipients, and liver and lung transplant recipients. The risk factors for infection in these groups are discussed. Because Aspergillus species are widespread in the environment, it is difficult to link specific sources and exposures to the development of human infections. However, molecular strain typing and other studies indicate that a significant number of Aspergillus infections are now being acquired outside the health care setting, either before patients are admitted to hospital, or after they have been discharged. The role of environmental control measures and antifungal drug prophylaxis in the prevention of hospital- and community-acquired aspergillosis is discussed.

Treatment of documented and suspected neutropenia-associated invasive fungal infections

Factors such as the intensification of anti-tumor regimens have enhanced both the depth and length of neutropenia and endorsed severe deficiencies in other immune systems. As a result, the risk of fungal infections has increased substantially. Clinicians should be aware of the possibility to enable a timely diagnosis because many of the problems in the management of invasive fungal infections during neutropenia are as much the consequence of diagnostic short-comings as of lack of therapeutic options. About 7% of all febrile episodes during neutropenia can ultimately be attributed to fungi, Candida and Aspergillus species being the paramount pathogens. Although the data in favor of prophylactic use of antifungals are not convincing, prophylaxis is still recommended in an attempt to protect particularly high-risk patients. Fluconazole still appears a suitable agent in recipients of a bone marrow transplant. Given the paucity of data, reappraisal of the value of empirical antifungal therapy is warranted. Amphotericin B with or without 5-flucytosine is considered the standard therapy for acute candidiasis with fluconazole as an alternative. Amphotericin B is also first-line therapy for invasive aspergillosis in neutropenic patients; lipid-based formulations are recommended for patients who develop nephrotoxity. Recovery of the granulocytes and other immune systems has shown to be of critical importance in the management of all invasive fungal infections.

In vitro antifungal activities of the new triazole UR-9825 against clinically important filamentous fungi

We used a modified reference microdilution method (the M-38P method) to evaluate the in vitro activities of the new triazole UR-9825 in comparison with those of amphotericin B against 77 strains of opportunistic filamentous fungi. UR-9825 was clearly more active than amphotericin B against all fungi except Fusarium solani and Scytalidium spp. Notably, UR-9825 had low MICs for Aspergillus fumigatus and Paecilomyces lilacinus (MICs at which 90% of isolates are inhibited, 0.125 microg/ml for both species).

In vitro antifungal susceptibility testing

With the rising frequency of fungal infections, as well as increasing reports of resistance to antifungal agents, it is imperative that clinically applicable antifungal susceptibility testing be available. In 1997 the National Committee for Clinical Laboratory Standards published standard guidelines for antifungal susceptibility testing of Candida sp and Cryptococcus neoformans with amphotericin B, flucytosine, fluconazole, itraconazole, and ketoconazole. Although the methods are standard, they are time consuming, can be difficult to interpret, and are approved only for testing limited organisms and drugs. Modifications to the methods and alternative approaches have been proposed to make these tests more convenient and efficient, applicable to a greater number of species, and appropriate for performing in the clinical laboratory.

Colletotrichum species as emerging opportunistic fungal pathogens: a report of 3 cases of phaeohyphomycosis and review

BACKGROUND

Numerous etiologic agents of subcutaneous phaeohyphomycosis have been reported. Colletotrichum spp, common plant pathogens, have been reported as a cause of ocular keratomycosis, but only one previous case of cutaneous disease (hyalohyphomycosis) has been attributed to this genus.

OBJECTIVE

Our purpose was to describe 3 cases of subcutaneous phaeohyphomycosis due to Colletotrichum spp occurring in patients undergoing chemotherapy for hematologic malignancies.

METHODS

Three cases of Colletotrichum-induced phaeohyphomycosis are reviewed. The clinical and histologic features of this infection are presented, the antifungal susceptibilities are reported, and treatment options are discussed.

RESULTS

We describe the first report in which C coccodes and C gloeosporioides are implicated as etiologic agents of subcutaneous phaeohyphomycosis. Despite treatment, one patient died after the onset of visceral fungal disease.

CONCLUSION

Colletotrichum spp may cause life-threatening phaeohyphomycosis in immunosuppressed patients. Prompt recognition and intervention with surgical and antifungal treatment may result in decreased morbidity and mortality associated with these infections.

Immune reconstitution after allogeneic marrow transplantation compared with blood stem cell transplantation

Allogeneic peripheral blood stem cell grafts contain about 10 times more T and B cells than marrow grafts. Because these cells may survive in transplant recipients for a long time, recipients of blood stem cells may be less immunocompromised than recipients of marrow. Immune reconstitution was studied in 115 patients randomly assigned to receive either allogeneic marrow or filgrastim-mobilized blood stem cell transplantation. Between day 30 and 365 after transplantation, counts of most lymphocyte subsets were higher in the blood stem cell recipients. The difference was most striking for CD4 T cells (about 4-fold higher counts for CD45RA(high) CD4 T cells and about 2-fold higher counts for CD45RA(low/-)CD4 T cells; P <.05). On assessment using phytohemagglutinin and herpesvirus antigen-stimulated proliferation, T cells in the 2 groups of patients appeared equally functional. Median serum IgG levels were similar in the 2 groups. The rate of definite infections after engraftment was 1.7-fold higher in marrow recipients (P =.001). The rate of severe (inpatient treatment required) definite infections after engraftment was 2.4-fold higher in marrow recipients (P =.002). The difference in the rates of definite infections was greatest for fungal infections, intermediate for bacterial infections, and lowest for viral infections. Death associated with a fungal or bacterial infection occurred between day 30 and day 365 after transplantation in 9 marrow recipients and no blood stem cell recipients (P =.008). In conclusion, blood stem cell recipients have higher lymphocyte-subset counts and this appears to result in fewer infections. (Blood. 2001;97:3380-3389)

Older patients with high-risk fungal infections can be successfully allografted using non-myeloablative conditioning in combination with intensified supportive care regimens

Leukaemic patients with advanced disease and severe fungal infections as well as older patients with substantial co-morbidity are usually excluded from conventional allotransplantation because of increased morbidity and mortality. We approached allogeneic transplantation in four patients with a median age of 62 years (one chronic myeloid leukaemia in blast crisis, one high-risk acute myeloid leukaemia (AML) in first complete remission (CR1), one AML in 2nd relapse, one AML in CR2 with pre-existing fungal lung infections (two aspergillus, two mucor) and additional co-morbidity (diabetes n = 2, aortic aneurysm n = 1, arterial sclerosis n = 2) by combining non-myeloablative conditioning with an intensified supportive care regimen, including amphotericin B and 4-12 (median 9) prophylactic granulocyte transfusions from granulocyte colony-stimulating factor (G-CSF)-stimulated volunteer donors. G-CSF was also given to patients until neutrophil recovery. All four patients recovered to a neutrophil count of 0.5 x 109/l after a median of 11.5 d (range 11-13 d). Prophylactic granulocyte transfusions also reduced the need for platelet transfusions and minimized mucositis. All patients were discharged at a median of 25 d (range 18-59 d) and are alive and well after a median follow-up of > 390 d (range 336-417 d) without evidence of leukaemia. Regression of the fungal lesions was documented in three patients, with a slight progression detected by computerized tomography scan of the chest in one patient. We conclude that pulmonary fungal infections are not a contraindication for allogeneic stem cell transplantation, if non-myeloablative conditioning regimens are used in combination with granulocyte transfusions, intravenous amphotericin B and G-CSF.

Dendritic cell-mediated stimulation of the in vitro lymphocyte response to Aspergillus

Lymphocytes play a major role in host defense against Aspergillus, but little is known about the contribution of dendritic cells (DC) to antifungal immunity in humans. We have observed that DC derived from normal volunteers phagocytose heat-killed A. fumigatus conidia. Following 24 h of exposure to the fungus, DC displayed an increase in the mean fluorescence intensity of HLA-DR, CD80, and CD86, and an increase in the percentage of CD54(+) cells. These DC also displayed increased production of IL-12. DC derived from CD34(+) progenitors or monocytes stimulated autologous lymphocytes to proliferate and produce high levels of interferon-gamma, but not interleukin-10, in response to fungal antigen. DC generated from CD34(+) progenitors collected prior to autologous or allogeneic stem cell transplantation also partially restored the in vitro antifungal proliferative response of lymphocytes obtained from patients 1 month after transplantation. These results suggest that DC are important to host-response to A. fumigatus, and that ex vivo-generated DC might be useful in restoring or enhancing the antifungal immunity after hematopoietic stem cell transplantation.

Preventing opportunistic infections after hematopoietic stem cell transplantation: the Centers for Disease Control and Prevention, Infectious Diseases Society of America, and American Society for Blood and Marrow Transplantation Practice Guidelines and beyond

This review presents evidence-based guidelines for the prevention of infection after blood and marrow transplantation. Recommendations apply to all myeloablative transplants regardless of recipient (adult or child), type (allogeneic or autologous) or source (peripheral blood, marrow or cord blood) of transplant. In Section I, Dr. Dykewicz describes the methods used to rate the strength and quality of published evidence supporting these recommendations and details the two dozen scholarly societies and federal agencies involved in the genesis and review of the guidelines. In Section II, Dr. Longworth presents recommendations for hospital infection control. Hand hygiene, room ventilation, health care worker and visitor policies are detailed along with guidelines for control of specific nosocomial and community-acquired pathogens. In Section III, Dr. Boeckh details effective practices to prevent viral diseases. Leukocyte-depleted blood is recommended for cytomegalovirus (CMV) seronegative allografts, while ganciclovir given as prophylaxis or preemptive therapy based on pp65 antigenemia or DNA assays is advised for individuals at risk for CMV. Guidelines for preventing varicella-zoster virus (VZV), herpes simplex virus (HSV) and community respiratory virus infections are also presented. In Section IV, Drs. Baden and Rubin review means to prevent invasive fungal infections. Hospital design and policy can reduce exposure to air contaminated with fungal spores and fluconazole prophylaxis at 400 mg/day reduces invasive yeast infection. In Section V, Dr. Sepkowitz details effective clinical practices to reduce or prevent bacterial or protozoal disease after transplantation. In Section VI, Dr. Sullivan reviews vaccine-preventable infections and guidelines for active and passive immunizations for stem cell transplant recipients, family members and health care workers.

Low B-cell and monocyte counts on day 80 are associated with high infection rates between days 100 and 365 after allogeneic marrow transplantation

To ascertain which mononuclear cell subset deficiency plays a role in the marrow transplant recipient's susceptibility to infections, mononuclear cell subset counts were prospectively determined in 108 patients on day 80. Infections occurring between day 100 and 365 were recorded by an investigator blinded to the subset counts. In univariate analyses, the counts of the following subsets showed a significant inverse correlation with infection rates: total B cells, IgD+ B cells, IgD− B cells, total CD4 T cells, CD28+ CD4 T cells, CD28− CD4 T cells, CD45RAlow/− CD4 T cells and monocytes. In multivariate analyses, the counts of the following subsets remained significantly inversely correlated with the infection rates: total B cells (P = .0004) and monocytes (P = .009). CD28− CD8 T-cell counts showed no correlation with infection rates. In conclusion, the susceptibility of patients to infections late posttransplant may be due in part to the slow reconstitution of B cells and monocytes.

Invasive fungal infections in pediatric bone marrow transplant recipients: single center experience of 10 years

Invasive fungal infections (IFI) with substantial mortality constitute an increasing problem among BMT patients. From 1986 to 1996 148 children underwent BMT, and are included in a retrospective analysis of the incidence, risk factors and outcome of IFI. By histopathology or culture-proven IFI (Candida, 10; Aspergillus, 8) was documented in 12/73 (16%) allogeneic and in 6/75 (8%) autologous BMT patients. Of these 18 patients, 15 subsequently died, and in 12 (66%) IFI was regarded as the main cause of death. In addition to the patients with documented IFI, 48 had suspected and 82 no fungal infection. Invasive candidal infections were more frequent in patients with semiquantitatively estimated abundant candidal colonization as compared with those with no colonization (18% vs 3%, P = 0.015). In the allogeneic group, 50% of those with severe (grades III-IV) aGVHD had IFI as opposed to 8% of those with no or mild aGVHD (P < 0.001). Regarding cGVHD, 57% of those with extensive cGVHD vs 5% of those with absent or limited cGVHD had IFI (P < 0.001). The dose of steroids was associated with IFI: 77% of those who received high-dose steroids (methylprednisolone 0.25-1 g/day for 5 days) vs 5% of those with conventional-dose (prednisone 2 mg/kg/day) had IFI (P < 0.001). Particularly for BMT patients at risk, new, quicker and better diagnostic tests and more effective anti-fungal agents, both for prophylaxis and treatment, are needed.

Low B-cell and monocyte counts on day 80 are associated with high infection rates between days 100 and 365 after allogeneic marrow transplantation

To ascertain which mononuclear cell subset deficiency plays a role in the marrow transplant recipient's susceptibility to infections, mononuclear cell subset counts were prospectively determined in 108 patients on day 80. Infections occurring between day 100 and 365 were recorded by an investigator blinded to the subset counts. In univariate analyses, the counts of the following subsets showed a significant inverse correlation with infection rates: total B cells, IgD+ B cells, IgD− B cells, total CD4 T cells, CD28+ CD4 T cells, CD28− CD4 T cells, CD45RAlow/− CD4 T cells and monocytes. In multivariate analyses, the counts of the following subsets remained significantly inversely correlated with the infection rates: total B cells (P = .0004) and monocytes (P = .009). CD28− CD8 T-cell counts showed no correlation with infection rates. In conclusion, the susceptibility of patients to infections late posttransplant may be due in part to the slow reconstitution of B cells and monocytes.

Treatment and outcome of invasive Aspergillus infections in allogeneic BMT recipients

The outcome of invasive aspergillosis (IA) has been considered poor in allogeneic BMT recipients. We analyzed retrospectively the treatment and outcome of IA diagnosed during life in a recent cohort of 20 allogeneic BMT recipients. All patients were initially treated with amphotericin B (AmB) (conventional 16, liposomal 4). Due to toxicity, conventional AmB was changed to a liposomal preparation in 10 patients. Five patients also received itraconazole and three underwent surgery. Of 19 evaluable patients, two patients achieved a complete response and a partial response was observed in five patients (response rate 37%). The median survival was 37 days after the diagnosis. Only two patients (10%) were cured. The prognosis of allogeneic BMT recipients with IA has remained poor. Although treatment responses are common, immunosuppression aggravated by GVHD and its treatment, as well as the commonly disseminated presentation of IA, seem to be major obstacles to the success of therapy. Bone Marrow Transplantation (2000) 26, 759-762.

The spectrum of Malassezia infections in the bone marrow transplant population

A consecutive series of 3044 patients who underwent BMT at the University of Minnesota over a 25 year period were reviewed for the post-transplant occurrence of infection caused by the yeast Malassezia furfur. Six patients, ranging in age from 1 to 54 years, developed Malassezia infections at a median of 59 days post transplant. Five patients were allogeneic transplant recipients; the remaining patient had undergone autologous transplantation. A spectrum of clinical manifestations of Malassezia infection was seen in these patients, including infections of mucosal surfaces and the skin, in addition to catheter-related fungemia. Unlike many of the other more common opportunistic fungal infections in immunocompromised patients, neutropenia and the use of broad-spectrum antimicrobials do not appear to be significant risk factors for Malassezia infections in the BMT population. In addition, disseminated fungal infection despite the presence of fungemia is uncommon. Lastly, the outcome of Malassezia infections in these patients, whether folliculitis, mucosal infection, or fungemia, appears to be quite favorable, in contrast to the poorer outcome with many other fungal infections in BMT patients. Catheter removal and discontinuation of intravenous lipids are important for a successful outcome in fungemic cases.

Detection of antifungal activity in Portulaca oleracea by a single-cell bioassay system

The antifungal activity of Portulaca oleracea extracts against hyphal growth of various fungi was evaluated in real time using an automatic single-cell bioassay system. Target organisms were the filamentous fungi Aspergillus and Trichophyton and the yeast Candida. A colony of test fungi was in contact with the assay medium, or assay medium containing plant extract, in sequence. The antifungal activity of each fraction of P. oleracea was evaluated based on the dynamic hyphal growth response curves of test fungi. A crude sample obtained by EtOAc extract showed a specific and marked activity against dermatophytes of the genera Trichophyton.

Central nervous system infections following bone marrow transplantation: an autopsy report of 27 cases

The authors retrospectively assess the autopsy findings of central nervous system (CNS) infections in marrow transplant recipients. From July 1987 to June 1998, 845 patients at our institution were submitted to bone marrow transplantation (BMT). The CNS of 180 patients was studied through autopsy and these patients had their medical records reviewed. Twenty-seven (15%) patients presented brain parenchyma infection. Fungi were isolated in approximately 60% of the cases. Mean survival time was 153 days (0-1,264 days) and the majority of the patients died during the first 3 months after BMT (18 cases; 67%). Aspergillus sp. were the most prevalent fungi (approximately 30%), followed by Candida sp. infection (approximately 18%). There was one case of Fusarium sp. infection and two cases of unidentified fungus. All patients with fungal infections had documented involvement at widespread sites. Toxoplasma gondii encephalitis was demonstrated in 8 patents (approximately 30%). Bacterial abscesses were responsible for approximately 11% of the findings. Eleven (41%) of the 27 patients died secondary to cerebral causes. These results show that infectious compromise of the CNS following BMT is a highly fatal event, caused mainly by fungi and T. gondii. Furthermore, they provide a likely guide to the possible causes of brain abscesses following BMT.

Invasive aspergillosis. Disease spectrum, treatment practices, and outcomes. I3 Aspergillus Study Group

A review of representative cases of invasive aspergillosis was conducted to describe current treatment practices and outcomes. Eighty-nine physicians experienced with aspergillosis completed case forms on 595 patients with proven or probable invasive aspergillosis diagnosed using modifications of the Mycoses Study Group criteria. Pulmonary disease was present in 56%, with disseminated infection in 19%. The major risk factors for aspergillosis were bone marrow transplantation (32%) and hematologic malignancy (29%), but patients had a variety of underlying conditions including solid organ transplants (9%), AIDS (8%), and pulmonary diseases (9%). Overall, high antifungal failure rates occurred (36%), and complete antifungal responses were noted in only 27%. Treatment practices revealed that amphotericin B alone (187 patients) was used in most severely immunosuppressed patients while itraconazole alone (58 patients) or sequential amphotericin B followed by itraconazole (93 patients) was used in patients who were less immunosuppressed than patients receiving amphotericin B alone. Response rate for patients receiving amphotericin B alone was poor, with complete responses noted in only 25% and death due to or with aspergillosis in 65%. In contrast, patients receiving itraconazole alone or following amphotericin B had death due to or with Aspergillus in 26% and 36%, respectively. These results confirm that mortality from invasive aspergillosis in severely immunosuppressed patients remains high even with standard amphotericin B. Improved responses were seen in the less immunosuppressed patients receiving sequential amphotericin B followed by itraconazole and those receiving itraconazole alone. New approaches and new therapies are needed to improve the outcome of invasive aspergillosis in high-risk patients.

Cunninghamella infection post bone marrow transplant: case report and review of the literature

Cunninghamella spp., in the class Zygomycete and order Mucorales, are unusual opportunistic pathogens that have been identified with increased frequency in immunocompromised patients. Infections with this group of organisms have been seen most frequently in patients with hematologic malignancy. We describe an allogeneic bone marrow recipient who developed fungal pneumonitis and disseminated fungal dermatitis caused by Cunninghamella spp. To our knowledge, this is the first reported case of Cunninghamella infection in a BMT recipient. The case highlights the mortality associated with opportunistic infections in immunocompromised patients and confirms the risk factors associated with non-candida fungal infections after bone marrow transplantation.

Aspergillus antigen testing in bone marrow transplant recipients

AIMS

To assess the clinical usefulness of a commercial aspergillus antigen enzyme linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in bone marrow transplant recipients, and to compare it with a commercial latex agglutination (LA) test.

METHODS

In total, 2026 serum samples from 104 bone marrow transplant recipients were tested. These comprised 67 sera from seven patients who had died with confirmed IA, 268 sera from nine patients who had died with suspected IA, and 1691 sera from 88 patients with no clinical, radiological, or microbiological signs of IA.

RESULTS

The ELISA was more sensitive than the LA test. All patients who were ELISA positive were also LA positive, and a positive LA result never preceded a positive ELISA. Twelve of 16 patients with confirmed or suspected IA were ELISA positive on two or more occasions, compared with 10 of 15 who were LA positive. ELISA was positive before LA in five patients (range, 2-14 days), and became positive on the same day in the remainder. Aspergillus antigen was detected by ELISA a median of 15 days before death (range, 4-233). Clinical and/or radiological evidence of IA was noted in all patients, and a positive ELISA was never the sole criterion for introduction of antifungal treatment. Two samples (one from each of two patients without IA) gave false positive results.

CONCLUSIONS

The aspergillus ELISA is a specific indicator of invasive aspergillosis if the criterion of two positive samples is required to confirm the diagnosis. However, the test is insufficiently sensitive to diagnose aspergillosis before other symptoms or signs are apparent, and hence is unlikely to lead to earlier initiation of antifungal treatment. It is therefore unsuitable for screening of asymptomatic patients at risk of invasive aspergillosis, but does have a useful role in confirming the diagnosis in symptomatic patients.

Comparison of commercial latex agglutination and sandwich enzyme immunoassays with a competitive binding inhibition enzyme immunoassay for detection of antigenemia and antigenuria in a rabbit model of invasive aspergillosis

A commercial latex agglutination assay (LA) and a sandwich enzyme immunoassay (SEIA) (Sanofi Diagnostics Pasteur, Marnes-la-Coquette, France) were compared with a competitive binding inhibition assay (enzyme immunoassay [EIA]) to determine the potential uses and limitations of these antigen detection tests for the sensitive, specific, and rapid diagnosis of invasive aspergillosis (IA). Toward this end, well-characterized serum and urine specimens were obtained by using a rabbit model of IA. Serially collected serum or urine specimens were obtained daily from control rabbits or from rabbits immunosuppressed and infected systemically with Aspergillus fumigatus. By 4 days after infection, EIA, LA, and SEIA detected antigen in the sera of 93, 93, and 100% of A. fumigatus-infected rabbits, respectively, whereas antigen was detected in the urine of 93, 100, and 100% of the rabbits, respectively. False-positive results for non-A. fumigatus-infected rabbits for EIA, LA, and SEIA were as follows: for serum, 14, 11, and 23%, respectively; for urine, 14, 84, and 90%, respectively. Therefore, although the sensitivities of all three tests were similar, the specificity was generally greater for EIA than for LA or SEIA. Infection was also detected earlier by EIA, by which the serum of 53% of A. fumigatus-infected rabbits was positive as early as 1 day after infection, whereas the serum of only 27% of the rabbits tested by LA was positive. Although the serum of 92% of A. fumigatus-infected rabbits was positive by SEIA as early as 1 day after infection, the serum of a high percentage (50%) was false positive before infection. The urine of 21% of A. fumigatus-infected rabbits was positive by EIA as early as 1 day after infection, and the urine of none of the rabbits was false positive before infection. When EIA results for urine specimens were combined with those for serum, sensitivity was improved (i.e., 67% of rabbits were positive by 1 day after infection and only one rabbit gave a false-positive result). A total of 93% of A. fumigatus-infected rabbits were positive for antigen in urine as early as 1 day after infection and the urine of 100% of the rabbits was positive by SEIA. However, before infection, 79% of A. fumigatus-infected rabbits were false positive for antigen in urine by LA and 90% were false positive for antigen in urine by SEIA. These data indicate that the EIA has the potential to be used to diagnose IA with both serum and urine specimens and to detect a greater number of infections earlier with greater specificity than the specificities achieved with the commercial tests.

Diagnostic aspects of invasive Aspergillus infections in allogeneic BMT recipients

To investigate diagnostic aspects of invasive aspergillosis (IA) in allogeneic BMT recipients, the charts of 22 consecutive patients with IA transplanted in 1989-1995 were reviewed. IA was diagnosed 69-466 days (median 131 days) post BMT. In 16 patients (73%), a definite or probable diagnosis of IA was made during life. Respiratory symptoms were the presenting feature in half of the patients followed by neurological symptoms (27%). Chest X-ray revealed single or multiple nodular lesions in 10 patients; cavitation was observed in five patients. Tissue biopsy was the most common method of diagnosis (nine patients: lungs 6, liver 1, subcutaneous tissue 1, brain 1). Five IA cases were detected by nine guided fine needle lung biopsies in eight patients and without complications. Bronchoalveolar lavage was performed in 14 patients with findings suggestive of invasive pulmonary aspergillosis in eight cases. Lungs were the most common organ affected (90%) followed by central nervous system (41%). The diagnosis of IA is still difficult, and a large number of patients have advanced infection at diagnosis. Methods for early diagnosis are needed. Patients with a clinical suspicion of IA should be treated vigorously with antifungal agents during the diagnostic work-up.

Haematopoietic cell transplantation in patients with Fanconi anaemia using alternate donors: results of a total body irradiation dose escalation trial

Allogeneic haematopoietic cell transplantation (HCT) is the only therapeutic modality capable of correcting the haematologic manifestations of Fanconi anaemia (FA). However, HCT from alternative donors has been associated with poor survival. Between June 1993 and July 1998, 29 FA patients (median age 12.1 years; range 3.7-48.5 years) were enrolled in a prospective phase I-II dose escalation study. All patients were treated with cyclophosphamide 40 mg/kg, total body irradiation (TBI) 450 cGy or 600 cGy and antithymocyte globulin (ATG), followed by HCT from an alternative donor. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A for 6 months, short course methylprednisolone (2 mg/kg/day) between days +5 and +19 and marrow T-cell depletion by counterflow elutriation. The probability of developing grade III-IV toxicity was 17% (95% CI 3-31%). For the 25 marrow recipients, the probability of neutrophil engraftment (ANC 0.5 x 109/l by day 45) was 63% (95% CI 42-82%). Probabilities of grade II-IV acute GVHD and chronic GVHD were 32% (95%CI 10-54%) and 0% respectively. With a median follow-up of 18 months, the probability of survival for the entire cohort at 1 year was 34% (95% CI 17-51%). The presence of lymphocyte somatic mosaicism [i.e. the presence of diepoxybutane (DEB)-insensitive cells] was associated with a significantly increased risk of graft failure. Disappointingly, the use of higher dose TBI and post-transplant ATG did not improve engraftment. More effective peritransplant immunosuppression, especially in FA patients with somatic mosaicism, was required to overcome the barrier of graft rejection. New conditioning regimens adapted to each individual's alkylator sensitivity are needed to improve the outcome of alternative donor HCT for FA.

Aspergillosis in bone marrow transplant recipients

Invasive aspergillosis in bone marrow transplant recipient is associated with a high mortality. Diagnosis is often delayed because the inflammatory response is blunted by immunosuppression. The gold standard of tissue biopsy is often considered too in invasive as the procedure is often complicated by bleeding and secondary infection. Recent finding on non-invasive tests such as serial measurement of peripheral blood galactomannan antigen or DNA appears to be promising. However, the limited availability of such tests and requirement for expertise are still hampering their use in routine clinical management. More often than not, initiation of antifungal therapy is empirical and based on suggestive radiological changes. Amphotericin B remains the gold standard of therapy but liposconal preparation may prove to be less nephrotoxic and equally effective. Treatment outcome depends more on the acceleration of the recovery of the immune system and the reduction of anti-GVHD therapy than the antifungal agent followed by surgical resection. The efficacy of many reported anti-aspergillosis prophylactic regimen has not been proved in randomized control trials. Despite the absence of data, such policy should still be considered in transplant units with high incidence of aspergillus or undergoing renovation.

The spectrum of Fusarium infection in immunocompromised patients with haematological malignancies and in non-immunocompromised patients: a single institution experience over 10 years

Fusarium is a newly emerging fungal pathogen associated with significant morbidity and mortality in the immunocompromised host. We have reviewed our hospital's experience with Fusarium between 1985 and 1995. Fusarium species were isolated from 22 specimens, representing 11 patients. Cases were not clustered by time period. The median age of the patients was 36.5 years (range 17-69 years). The sources of the organism were 12 skin lesions from eight patients, seven blood cultures from two patients and one specimen each from a Hickman catheter tip, nail clippings and a bronchoalveolar lavage. Seven of the patients had chemotherapy-induced neutropenia when the Fusarium was isolated. Five of them developed invasive fusarosis during acute leukaemia induction treatment. They remained neutropenic, and none survived. The other two patients recovered from neutropenia and were treated successfully for this infection. The remaining four patients were not neutropenic or immunocompromised. Three grew Fusarium from skin or nail clippings and one from bronchial alveolar lavage (BAL). There was no evidence of invasive disease in any of the four. None of them received antifungal therapy, and they were all alive at last follow-up. We conclude that Fusarium is a newly emerging infection in neutropenic patients. A high index of suspicion, especially for skin lesions, will help in early diagnosis before systemic and visceral dissemination. Excision of the initial focus of infection and antifungal therapy, aided by speedy neutrophil recovery, are likely to protect patients threatened with these fatal infections. Fusarium isolated from non-neutropenic, non-immunosuppressed patients is not significant and does not merit systemic antifungal treatment.

Proton translocating ATPase mediated fungicidal activity of a novel complex carbohydrate: CAN-296

CAN-296 is a complex carbohydrate (approximately 4300 Da) isolated from the cell wall of Mucor rouxii. It exhibits excellent in vitro fungicidal activity against a wide spectrum of pathogenic yeasts, including isolates resistant to azoles and polyenes. The rapid irreversible action of CAN-296 on intact fungal cells and protoplasts suggested a membrane-located target for its action. The proton translocating ATPase (H+-ATPase) of fungi is an essential enzyme required for the regulation of intracellular pH and nutrient transport. Inhibition of H+-ATPase leads to intracellular acidification and cell death. We therefore investigated the effect of CAN-296 on H+-ATPase-mediated proton pumping by intact cells of Candida and Saccharomyces species by measuring the glucose-induced acidification of external medium. CAN-296 inhibited proton pumping of Candida albicans, Candida glabrata, Candida krusei, Candida guilliermondii and Saccharomyces cerevisiae at low concentrations (0.078-1.25 mg/l). Other commonly used antifungal agents such as amphotericin B, itraconazole and fluconazole had no effect on H+-ATPase-mediated proton pumping. A clinical isolate of C. glabrata with reduced in vitro susceptibility (MIC = 10 mg/l) to CAN-296 also showed resistance to CAN-296 inhibition of proton pumping. Purified membrane fractions rich in H+-ATPase activity were not inhibited by CAN-296 suggesting that the effect on the H+-ATPase-mediated proton pumping in intact yeast cells is an indirect effect, perhaps mediated by local or global disruption of the plasma membrane. These results suggest that the inhibition of fungal H+-ATPase is at least partly responsible for the antifungal activity of CAN-296.

In vitro activity of the new triazole BMS-207147 against Aspergillus species in comparison with itraconazole and amphotericin B

The in vitro activity of BMS-207147 against 80 clinical isolates of Aspergillus was compared with that of itraconazole and amphotericin B, using a validated microtiter method. Geometric mean MICs (in microg/ml) were as follows: 1.71 for BMS-207147, 0.67 for itraconazole, and 0.63 for amphotericin B. The range of concentrations of each drug was 0.125 to >16 microg/ml. Aspergillus fumigatus was significantly more susceptible to BMS-207147 (P < 0. 05) than A. terreus and A. flavus. No BMS-207147-resistant A. fumigatus isolates were identified, though eight itraconazole-resistant (MIC, >8 microg/ml) isolates were. BMS-207147 is active against Aspergillus spp. at slightly high concentrations compared with itraconazole and amphotericin B.

Alteration of cell wall composition leads to amphotericin B resistance in Aspergillus flavus

An amphotericin B (AmB)-resistant mutant was isolated from a wild-type AmB-susceptible strain of Aspergillus flavus by serial transfer of conidia on agar plates containing stepwise increased concentrations of AmB up to 100 microg ml-1. The acquired resistance of mycelia was specific for polyene-antibiotics AmB, nystatin and trichomycin. Spheroplasts derived from the resistant mycelia were as susceptible to AmB as the wild-type. Chemical analysis of the cell wall revealed that levels of alkali-soluble and -insoluble glucans were significantly higher in the resistant mycelia as compared to those in the wild-type. When resistant mycelia were treated with SDS, they adsorbed as much AmB as wild-type mycelia. These results suggest that alterations in the cell wall components of mycelia, especially 1,3-alpha-glucan and protein complex in the outermost wall layer, lead to AmB resistance in A. flavus.

Fungal infections in patients undergoing blood and marrow transplantation

Fungal infections are currently a leading cause of infectious morbidity and mortality in patients undergoing allogeneic blood and marrow transplantation (BMT). Although the introduction of azole antifungals for prophylaxis has had a significant impact on the incidence of candidal infections (especially those caused by C. albicans and C. tropicalis), invasive aspergillosis has increased in incidence in many centers worldwide. Given the long risk period corresponding with graft-versus-host disease, and the toxicities of currently available mold-active antifungals, the development of a prevention strategy for these angioinvasive molds remains a challenge. The introduction of new antifungal drugs and adjunctive therapy to improve immune function may be beneficial in decreasing mortality associated with these infections in the future. Most importantly, a greater understanding of the pathogenesis of fungal disease and specific host risks is necessary to impact this increasingly important infection in immunocompromised hosts.

Proton-pumping-ATPase-targeted antifungal activity of a novel conjugated styryl ketone

NC1175 (3-[3-(4-chlorophenyl)-2-propenoyl]-4-[2-(4-chlorophenyl)vinyle ne]-1- ethyl-4-piperidinol hydrochloride) is a novel thiol-blocking conjugated styryl ketone that exhibits activity against a wide spectrum of pathogenic fungi. Incubation of NC1175 with various concentrations of cysteine and glutathione eliminated its antifungal activity in a concentration-dependent fashion. Since NC1175 is a lipophilic compound that has the potential to interact with cytoplasmic membrane components, we examined its effect on the membrane-located proton-translocating ATPase (H(+)-ATPase) of yeast (Candida albicans, Candida krusei, Candida guilliermondii, Candida glabrata, and Saccharomyces cerevisiae) and Aspergillus (Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, and Aspergillus nidulans) species. The glucose-induced acidification of external medium due to H(+)-ATPase-mediated expulsion of intracellular protons by these fungi was measured in the presence of several concentrations of the drug. NC1175 (12.5 to 50 microM) inhibited acidification of external medium by Candida, Saccharomyces, and Aspergillus species in a concentration-dependent manner. Vanadate-inhibited hydrolysis of ATP by membrane fractions of C. albicans was completely inhibited by 50 microM NC1175, suggesting that the target of action of NC1175 in these fungi may include H(+)-ATPase.

Role of newer azoles in surgical patients

Fungal infection has become an important cause of morbidity and mortality in critically ill surgical patients. Surgical patients at highest risk for invasive mycoses include those undergoing extensive abdominal surgery, those with underlying malignancy or other immunosuppressive conditions, and patients undergoing transplantation. Nosocomial candidemia remains a major complication for patients in surgical intensive units; however, the epidemiology of invasive fungal infection continues to change with molds and yeasts other than Candida albicans emerging as important causes of infection especially in immunosuppressed patients. This changing epidemiology has resulted in the need for an expanded armamentarium of antifungal therapies. One effective approach has been the utilization of higher doses of well-tolerated azoles, such as fluconazole, particularly against yeasts with dose-dependent susceptibility. Alternatively, the presumptive use of therapeutic doses of fluconazole may be indicated in intensive care unit patients with persistent leukocytosis and fever in whom a source of fever cannot be identified, particularly if the patient is extensively colonized at mucosal sites with yeast. New azoles with an expanded spectrum of activity are in development. These include agents include voriconazole, which has activity against resistant yeasts and molds and is in phase III clinical trials, posaconazole (Sch 56592) and ravuconazole (BMS-207147)--both of which are less advanced in clinical development, but which also offer an expanded spectrum of activity. Other new azoles with expanded activity are still in the early phases of development. In this review, strategies for optimizing use of the clinically available new azoles and the potential for new agents are discussed.

Approaches to fungal diagnosis in transplantation

The diagnosis of invasive fungal infection in patients undergoing solid organ or bone marrow transplantation remains a significant clinical challenge. Consideration of the epidemiology of these infections and host risk factors may be an important clue to a specific fungal diagnosis. Despite extensive investigation on methods such as serologic techniques to improve the rapid diagnosis of these infections, the diagnosis of invasive mycoses remains largely dependent on clinical presentation. For example, the signs and symptoms that result from angioinvasion of fungal organisms include pleuritic chest pain or hemoptysis. In a high-risk patient these findings can be important clues to invasive fungal infection. Cultures of opportunistic fungi in certain settings, such as Aspergillus in respiratory samples from immunosuppressed patients, may be associated with infection. Radiographic findings can also be useful to establish a diagnosis of infection. In patients with invasive aspergillosis as well as other angioinvasive moulds, chest CT scans may demonstrate lesions that are not visible on plain radiographs. Serodiagnosis of these infections remains largely investigational. Microbiological antifungal resistance has increasingly been reported, but in patients at high risk for serious fungal infection, including patients undergoing bone marrow and organ transplantation, antifungal resistance remains uncommon, particularly in Candida albicans. Higher doses of azoles should be used to treat patients with infections due to less susceptible yeasts and those with more serious infection. Prompt recognition of fungal infection combined with intensive antifungal therapy is needed for successful therapy.

Effect of amphotericin B lipid formulation on immune response in aspergillosis

The immune response against Aspergillus fumigatus has been studied during infection and therapy in order to understand the mechanism of pathogenesis and the effect of treatment with amphotericin B. With this in view an animal model of aspergillosis was developed in Balb/c mice by intravenous injection of an optimized dose of 3. 6x10(6) A. fumigatus spores. Infection due to Aspergillus was well established by histopathological examination and fungal load in the animal. Lesions and eosinophil infiltration was observed in the infected tissues which indicated the involvement of a Type I hypersensitivity response. Evaluation of serological parameters indicated high levels of interleukin-4 (IL-4) and A. fumigatus specific IgG antibodies. The reduction in fungal load and modulation of immune response in the infected mice was studied following treatment with amphotericin B/cholesterol hemisuccinate vesicles (ABCV). The results clearly indicated significant reduction in the fungal load, disappearance of eosinophils and lesions with the appearance of macrophages and neutrophils in the infected lung tissue, a decrease in IL-4 (fourfold) and a concomitant increase of interferon-gamma (IFN-gamma; twofold) with an improvement in general condition of mice. In the non-treated mice, the rise of IL-4 level indicated the association of T(H)2 cell response with susceptibility to infection while the increase of IFN-gamma in the treated group suggested that T(H)1 cell response may be involved in resistance to Aspergillus infection.

Leucocyte transfusions from rhG-CSF or prednisolone stimulated donors for treatment of severe infections in immunocompromised neutropenic patients

Sepsis in profound neutropenia after chemotherapy is associated with high mortality despite appropriate antibacterial or antifungal treatment. In a prospective phase I/II study we evaluated the feasability and efficacy of leucocyte transfusions (LT) in patients with malignancies or haematological disorders who were suffering from severe bacterial or fungal infection during therapy-related bone marrow aplasia. 30 patients with severe neutropenia and clinical signs of life-threatening sepsis not responding to adequate treatment, received LT from rhG-CSF-stimulated family donors or from prednisolone-primed volunteers. A total of 301 LT were administered. The median number of LT per patient was seven (range three to 65), the median duration of LT treatment was 8 d (range 2-35). The white cell count (WBC), absolute neutrophil count (ANC) and lymphocyte count of the concentrates from rhG-CSF-stimulated donors were significantly higher than those from prednisolone-primed volunteers (P = 0.0001). Despite the critical condition of the patients, LT were generally well tolerated. Only 39 (12.9%) LT were associated with adverse reactions. The transfusion of leucocytes collected by continuous flow leukapheresis from both rhG-CSF and prednisolone stimulated donors resulted in a measurable increment of the peripheral leucocyte and ANC counts in our patients. On day 100 after the first LT, 20/30 patients were alive with complete clearance of the infection.

Comparison of E-test and broth microdilution methods for antifungal drug susceptibility testing of molds

We compared the E test with a broth microdilution method, performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines, for determining the in vitro susceptibilities of 90 isolates of pathogenic molds (10 Absidia corymbifera, 10 Aspergillus flavus, 10 Aspergillus fumigatus, 10 Aspergillus niger, 10 Aspergillus terreus, 10 Exophiala dermatitidis, 10 Fusarium solani, 10 Scedosporium apiospermum, 5 Scedosporium prolificans, and 5 Scopulariopsis brevicaulis). Overall, there was 71% agreement between the results of the two methods for amphotericin B (E-test MICs within +/-2 log2 dilutions of broth microdilution MICs) and 88% agreement with the results for itraconazole. The overall levels of agreement (within +/-2 log2 dilutions) were >/=80% for 5 of the 10 species tested against amphotericin B and 8 of the 10 species tested against itraconazole. The best agreement between the results was seen with A. fumigatus and A. terreus (100% of results for both agents within +/-2 log2 dilutions). The poorest agreement was seen with S. apiospermum, S. prolificans, and S. brevicaulis tested against amphotericin B (20% of results within +/-2 log2 dilutions). In every instance, this low level of agreement was due to isolates for which the broth microdilution MICs were low but for which the E-test MICs were much higher. The E test appears to be a suitable alternative procedure for testing the susceptibility of Aspergillus spp. and some other molds to amphotericin B or itraconazole.

Comparison of in vitro activity of liposomal nystatin against Aspergillus species with those of nystatin, amphotericin B (AB) deoxycholate, AB colloidal dispersion, liposomal AB, AB lipid complex, and itraconazole

We compared the in vitro activity of liposomal nystatin (Nyotran) with those of other antifungal agents against 60 Aspergillus isolates. Twelve isolates were itraconazole resistant. For all isolates, geometric mean (GM) MICs (micrograms per milliliter) were 2.30 for liposomal nystatin, 0.58 for itraconazole, 0.86 for amphotericin B (AB) deoxycholate, 9.51 for nystatin, 2.07 for liposomal AB, 2.57 for AB lipid complex, and 0.86 for AB colloidal dispersion. Aspergillus terreus (GM, 8.72 micrograms/ml; range, 8 to 16 micrograms/ml) was significantly less susceptible to all of the polyene drugs than all other species (P = 0.0001).

In vitro activity of Syn-2869, a novel triazole agent, against emerging and less common mold pathogens

The in vitro activity of Syn-2869 was compared with that of amphotericin B and itraconazole. MICs for 100 isolates of pathogenic molds belonging to 12 species were determined by a broth microdilution adaptation of the method recommended by the National Committee for Clinical Laboratory Standards. Syn-2869 and itraconazole showed comparable, good activity against the dematiaceous molds Cladophialophora bantiana, Cladophialophora carrionii, Exophiala dermatitidis, Fonsecaea pedrosoi, Phialophora parasitica, and Ramichloridium mackenziei. Neither of the azole agents was active against the hyaline molds Fusarium solani, Scedosporium prolificans, and Scopulariopsis brevicaulis, but both were more active than amphotericin B against Scedosporium apiospermum. The MICs of the three agents were comparable for the mucoraceous mold Absidia corymbifera, but Syn-2869 appeared to be the least active against the dimorphic mold Sporothrix schenckii. Our results suggest that Syn-2869 could be effective against a range of mold infections in humans.

Fatal disseminated Trichoderma longibrachiatum infection in an adult bone marrow transplant patient: species identification and review of the literature

Trichoderma longibrachiatum was recovered from stool surveillance cultures and a perirectal ulcer biopsy specimen from a 29-year-old male who had received an allogeneic bone marrow transplant for acute lymphoblastic leukemia. The amphotericin B (2.0 microgram/ml) and itraconazole (1.0 microgram/ml) MICs for the organism were elevated. Therapy with these agents was unsuccessful, and the patient died on day 58 posttransplantation. At autopsy, histologic sections from the lungs, liver, brain, and intestinal wall showed infiltration by branching septate hyphae. Cultures were positive for Trichoderma longibrachiatum. While Trichoderma species have been recognized to be pathogenic in profoundly immunosuppressed hosts with increasing frequency, this is the first report of probable acquisition through the gastrointestinal tract. Salient features regarding the identification of molds in the Trichoderma longibrachiatum species aggregate are presented.