Antifungal prophylaxis during neutropenia and immunodeficiency

Prolonged fluconazole prophylaxis is associated with persistent protection against candidiasis-related death in allogeneic marrow transplant recipients: long-term follow-up of a randomized, placebo-controlled trial

Two randomized, placebo-controlled trials previously showed that fluconazole (400 mg/d) administered prophylactically decreases the incidence of candidiasis in blood and marrow transplant (BMT) recipients. However, there exists conflicting data regarding the optimal duration of fluconazole administration, specifically whether prophylaxis through acute graft-versus-host disease (GVHD) results in improved survival in allograft recipients. Reported here are the results of long-term follow-up and a detailed analysis of invasive candidiasis and candidiasis-related death in 300 patients who received fluconazole (400 mg/d) or placebo for 75 days after BMT at the Fred Hutchinson Cancer Research Center. Patients in both treatment arms were compared for survival, causes of death, and the incidence of invasive fungal infections early (less than 110 days) and late (more than 110 days) after BMT. After 8 years of follow-up, survival is significantly better in fluconazole recipients compared with placebo recipients (68 of 152 vs 41 of 148,P = .0001). The overall incidence of invasive candidiasis was increased in patients who received placebo compared with fluconazole (30 of 148 vs 4 of 152, P < .001). More patients who received placebo died with candidiasis early (13 of 148 vs 1 of 152, P = .001) and late (8 of 96 vs 1 of 121,P = .0068) after BMT. The incidence of severe GVHD involving the gut was higher in patients who did not receive fluconazole (20 of 143 vs 8 of 145, P = .02), and fewer patients who received fluconazole died with this complication. Thus, administration of fluconazole (400 mg/d) for 75 days after BMT appears to be associated with decreased gut GVHD, a persistent protection against disseminated candidal infections and candidiasis-related death, resulting in an overall survival benefit in allogeneic BMT recipients.

Single-dose AmBisome (Liposomal amphotericin B) as prophylaxis for murine systemic candidiasis and histoplasmosis

AmBisome is a liposomal formulation of amphotericin B that has broad-spectrum antifungal activity and greatly reduced toxicity compared to the parent drug. In this study, amphotericin B deoxycholate (Fungizone) (1 mg/kg) and AmBisome (1 to 20 mg/kg) were tested as single-dose prophylactic agents in both immunocompetent and immunosuppressed C57BL/6 mice challenged with either Candida albicans or Histoplasma capsulatum. Prophylactic efficacy was based on survival and fungal burden in the target organ (kidneys or spleen). At 9 to 10 days after histoplasma challenge, 80 to 90% of both immunocompetent and immunosuppressed mice in the control and Fungizone groups had died. All AmBisome-treated mice survived, although in the AmBisome groups given 1 mg/kg, the mice became moribund by day 10 to 12. No spleen CFU were detected in the histoplasma-challenged mice given 10 or 20 mg of AmBisome per kg. By 23 to 24 days after histoplasma challenge, fungal growth and/or death had occurred in all immunosuppressed mice except for four mice receiving 20 mg of AmBisome per kg. There were still no detectable fungi in the spleens of immunocompetent mice given 10 or 20 mg of AmBisome per kg. In the C. albicans experiment at 7 days postchallenge, all animals in both untreated and treated groups were alive with culture-positive kidneys. The kidney fungal burdens in AmBisome groups given 5 to 20 mg/kg were at least 1 log unit lower than those in the Fungizone group and significantly lower than those in the untreated control group (P < 0.05). There was a trend toward decreasing fungal growth in the kidneys as the dose of AmBisome was increased. In conclusion, these results show that a single high dose of AmBisome (5 to 20 mg/kg) had prophylactic efficacy in immunocompetent and immunosuppressed murine H. capsulatum and C. albicans models.

Prevention and prophylaxis of invasive fungal sinusitis in the immunocompromised patient

Fungal infections are a leading cause of morbidity and mortality among immunocompromised patients. Invasive fungal sinusitis is a devastating complication of immunosuppression. Treatment options are limited and often ineffective, making prevention important. Measures to decrease environmental exposure, indications for antifungal prophylaxis, and limitations of current regimens are discussed.

Oral manifestations of primary immunological diseases

BACKGROUND

Primary immunodeficiencies have many oral manifestations. The clinical presentation of these diseases demonstrates the roles of different immune cells for the maintenance of oral health.

METHODS

The authors reviewed selected literature describing systemic and oral manifestations of the primary immunodeficiencies published between 1966 and 1999.

RESULTS

The authors found that oral candidiasis and herpetic infections are seen frequently in patients with T-cell deficiencies, while patients with B-cell deficiencies are most susceptible to bacterial infections. Periodontitis and oral candidiasis are found in some, but not all, phagocyte deficiencies.

CONCLUSIONS

These findings demonstrate that T cells, B cells and phagocytes all have roles in oral immunity.

CLINICAL IMPLICATIONS

Acquired conditions that affect the immune system such as diabetes, alcoholism and acquired immunodeficiency syndrome, as well as certain medications, will affect oral defense mechanisms. The effects that acquired immunodeficiencies will have on oral health can be predicted from the oral manifestations of primary immunodeficiencies.

Invasive aspergillosis as an opportunistic infection in nonallografted patients with multiple myeloma: a European Organization for Research and Treatment of Cancer/ Invasive Fungal Infections Cooperative Group and the Intergroupe Français du Myélome

We report the occurrence of invasive aspergillosis (IA) in nonallografted patients with multiple myeloma (MM) who were treated at hematology or oncology centers in Europe during 1984-1996. Thirty-one cases met the criteria for definitive (21 [68%]) or probable (10 [32%]) IA. Of these cases, 23 (74%) were reported during 1992-1996. Twenty-nine cases (94%) occurred in patients with Durie-Salmon stage 3 MM, and 2 (6%) occurred in patients with Durie-Salmon stage 2 MM. The median time between MM and IA diagnoses was 8 months (range, 1-75 months). Sixteen patients (51%) had a neutrophil count </=500/mm3 for a median duration of 19 days (range, 10-37 days). Fourteen patients (45%) had recently received corticosteroid therapy, and 11 (36%), high doses of melphalan. Twenty-eight patients had primary pulmonary IA, and 3 had primary sinus IA. Forty-five percent of patients were considered to have died of IA. IA occurs as a potentially lethal opportunistic infection in intensively treated nonallografted patients with myeloma.

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.

Penicilliosis marneffei: another AIDS defining illness in Southeast Asia

Penicilliosis marneffei, a common mycosis among AIDS patients living in Southeast Asia, has been recently suggested for inclusion in the AIDS surveillance case definition. Infections with Penicillium marneffei were rare in the past, but infections with this dimorphic fungus have increased with the endemic of AIDS in the region. The reservoir of P. marneffei in nature is still unknown, although it seems likely that inhalation may be the route of entry of the organism leading to infection in humans. P. marneffei can cause two clinical types of the disease; focal and fatal progressive, disseminated infections, characterized by a variety of symptoms which can mimic those of other diseases. Oral P. marneffei lesions usually occur in patients with disseminated infections, presenting as shiny papules, as erosions or as shallow ulcers covered with whitish yellow, necrotic slough which may be found on the palate, gingiva, labial mucosa, tongue and oropharynx. Biopsy and culture provide definitive diagnoses, while serologic tests for both antibody and antigen are useful in rapid presumptive diagnoses as well as in surveillance studies of the prevalence and latency of the infection. Penicilliosis marneffei is a treatable disease, but late diagnosis and treatment may be fatal. Itraconazole and ketoconazole are the drugs of first choice for mild to moderately severe forms of the disease, whereas parenteral therapy with amphotericin B may be required for seriously ill patients. Recurrence of the disease is common, therefore maintenance is recommended. As reported, prophylaxis generating resistant strains are likely to develop.

Emerging Issues in Nosocomial Fungal Infections

Nosocomial fungal infections remain a serious cause of morbidity and mortality. As immunodeficient populations increase, the incidence of nosocomial fungal infections continues to rise. Although a wide variety of new and emerging fungi can cause nosocomial infections, Candida species remain the major etiologic agent. Candida species vary in their epidemiology and therapy. New diagnostic, epidemiologic, and therapeutic tools have been developed and are discussed in this review. They include the use of polymerase chain reaction-based diagnostic methods, recent advances in antifungal susceptibility testing, and comparative therapeutic and prophylactic trials. As advances in prevention, diagnosis, and therapy continue, nosocomial fungal infections and the morbidity and mortality associated with them can be reduced.

Antagonism of azole activity against Candida albicans following induction of multidrug resistance genes by selected antimicrobial agents

Antifungal azoles (e.g., fluconazole) are widely used for prophylaxis or treatment of Candida albicans infections in immunocompromised individuals, such as those with AIDS. These individuals are frequently treated with a variety of additional antimicrobial agents. Potential interactions between three azoles and 16 unrelated drugs (antiviral, antibacterial, antifungal, and antiprotozoal agents) were examined in vitro. Two compounds, tested at concentrations achievable in serum, demonstrated an antagonistic effect on azole activity against C. albicans. At fluconazole concentrations two to four times the 50% inhibitory concentration, C. albicans growth (relative to treatment with fluconazole alone) increased 3- to 18-fold in the presence of albendazole (2 microg/ml) or sulfadiazine (50 microg/ml). Antagonism (3- to 78-fold) of ketoconazole and itraconazole activity by these compounds was also observed. Since azole resistance has been correlated with overexpression of genes encoding efflux proteins, we hypothesized that antagonism results from drug-induced overexpression of these same genes. Indeed, brief incubation of C. albicans with albendazole or sulfadiazine resulted in a 3-to->10-fold increase in RNAs encoding multidrug transporter Cdr1p or Cdr2p. Zidovudine, trimethoprim, and isoniazid, which were not antagonistic with azoles, did not induce these RNAs. Fluphenazine, a known substrate for Cdr1p and Cdr2p, strongly induced their RNAs and, consistent with our hypothesis, strongly antagonized azole activity. Finally, antagonism was shown to require a functional Cdr1p. The possibility that azole activity against C. albicans is antagonized in vivo as well as in vitro in the presence of albendazole and sulfadiazine warrants investigation. Drug-induced overexpression of efflux proteins represents a new and potentially general mechanism for drug antagonism.

Efficacy of prevention by high-efficiency particulate air filtration or laminar airflow against Aspergillus airborne contamination during hospital renovation

OBJECTIVE

To evaluate efficacy of laminar airflow facilities plus high-efficiency particulate air (HEPA) filtration and HEPA filtration alone in preventing environmental Aspergillus contamination during hospital renovation. To show the usefulness of environmental surveillance to facilitate protection of patients at risk for invasive pulmonary aspergillosis.

DESIGN

Prospective sampling of air and surfaces for Aspergillus conidia during 2-year period.

SETTING

A hematological department adjacent to building renovation at a university hospital.

RESULTS

1,047 air samples and 1,178 surface samples were collected from January 1996 to December 1997. Significantly more air samples were positive for Aspergillus species during the period of building renovation than during the periods before and after renovation in a unit without a protected air supply adjacent to the building work area (51.5% vs 31.7%; odds ratio [OR], 2.3; 95% confidence interval [CI95], 1.4-3.7; P<.001). A major increase in the frequency of positive air samples was also found in another adjacent unit that was protected with HEPA filtration alone (from 1.8% to 47.5%; OR, 48.9; CI95, 12-229; P<10(-7)). In addition, in this unit, the mean count of Aspergillus conidia in positive air samples increased significantly during construction (4 colony-forming units [CFU]/m3 to 24.7 CFU/m3; P=.04) and the proportion of positive surface samples showed a significant increase during renovation (from 0.4% to 9.7%; OR, 28.3; CI95, 3.4-623; P=10(-4)). However, none of 142 air samples collected during renovation in the area protected with laminar airflow plus HEPA filtration showed Aspergillus conidia. In a unit distant from the building renovation site, the results of air and surface samples were not affected by renovation.

CONCLUSION

This study showed a strong association between building renovation and an increase in environmental Aspergillus contamination. Results confirmed the high efficacy of laminar airflow plus HEPA filtration and a high air-change rate. Although filtration with HEPA was effective during normal conditions, it alone was unable to prevent the rise of Aspergillus contamination related to building renovation. This study emphasized the necessity of an environmental survey of airborne contamination related to construction, to facilitate prevention of nosocomial aspergillosis outbreaks. A standardized protocol for aerobiological surveillance is needed.

Current and emerging azole antifungal agents

Major developments in research into the azole class of antifungal agents during the 1990s have provided expanded options for the treatment of many opportunistic and endemic fungal infections. Fluconazole and itraconazole have proved to be safer than both amphotericin B and ketoconazole. Despite these advances, serious fungal infections remain difficult to treat, and resistance to the available drugs is emerging. This review describes present and future uses of the currently available azole antifungal agents in the treatment of systemic and superficial fungal infections and provides a brief overview of the current status of in vitro susceptibility testing and the growing problem of clinical resistance to the azoles. Use of the currently available azoles in combination with other antifungal agents with different mechanisms of action is likely to provide enhanced efficacy. Detailed information on some of the second-generation triazoles being developed to provide extended coverage of opportunistic, endemic, and emerging fungal pathogens, as well as those in which resistance to older agents is becoming problematic, is provided.

Disseminated aspergillosis caused by Aspergillus ustus in a patient following allogeneic peripheral stem cell transplantation

The first case of disseminated aspergillosis caused by Aspergillus ustus in an allogeneic peripheral stem cell transplant patient is described. The patient, a 46-year-old female with a history of myelodysplastic syndrome, underwent high-dose chemotherapy and total body irradiation prior to transplantation. She was released from the hospital 49 days posttransplant (p.t.) in a stable condition with an absolute neutrophil count (ANC) of 2,700 cells per microl. Multiple antimicrobial agents, including itraconazole (ITR), were prescribed during hospitalization and at the time of discharge. Three days after discharge, the patient was readmitted with hemorrhagic cystitis, persistent thrombocytopenia, and bilateral pulmonary consolidation, although no fever was present. The ANC at the time of readmission was 3,500. Upon detection of a pulmonary nodule (day 67 p.t.), a bronchoalveolar lavage was performed; the lavage fluid was positive for both cytomegalovirus and parainfluenza virus and negative for fungus. The patient was placed on ganciclovir. A biopsy specimen from a leg lesion also noted on day 67 p.t. revealed septate hyphae consistent with Aspergillus species, and a culture subsequently yielded Aspergillus ustus. Confirmation detection of A. ustus was made by demonstration of characteristic reproductive structures with the presence of Hülle cells. On day 67 p.t., ITR was discontinued and liposomal amphotericin B (AMB) was initiated. The patient's condition worsened, and she died 79 days p.t. At the time of autopsy, septate hyphae were present in heart, thyroid, and lung tissues, with lung tissue culture positive for A. ustus. In vitro susceptibility testing indicated probable resistance to AMB but not to ITR. This case supports the need for the development of rapid methods to determine antifungal susceptibility.

Sordarins: A new class of antifungals with selective inhibition of the protein synthesis elongation cycle in yeasts

GR135402, a sordarin derivative, was isolated in an antifungal screening program. GR135402, sordarin, and derivatives of both compounds were evaluated for their ability to inhibit cell-free translational systems from five different pathogenic fungi (Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, and Cryptococcus neoformans). The activity profile of GR135402 is extended to other chemical compounds derived from sordarin. Experimental results indicate that sordarin analogs exert their antifungal effects by specifically inhibiting the protein synthesis elongation cycle in yeasts but do not affect protein synthesis machinery in mammalian systems. Intrinsically resistant strains owe their resistance to differences in the molecular target of sordarins in these strains. Preliminary studies performed to elucidate the mode of action of this new class of antifungal agents have shown that the putative target of sordarins is one of the protein synthesis elongation factors.

The expression of the secreted aspartyl proteinases Sap4 to Sap6 from Candida albicans in murine macrophages

Medically important yeasts of the genus Candida secrete aspartyl proteinases (Sap), which are of particular interest as virulence factors. Six closely related gene sequences, SAP1 to SAP6, for secreted proteinases are present in Candida albicans. The methylotrophic yeast Pichia pastoris was chosen as an expression system for preparing substantial amounts of each Sap isoenzyme. Interestingly, Sap4, Sap5 and Sap6, which have not yet been detected in C. albicans cultures in vitro, were produced as active recombinant enzymes. Different Sap polyclonal antibodies were raised in rabbits and tested before further application by enzyme-linked immunosorbent assay (ELISA) against each recombinant Sap. Two antisera recognized only Sap4 to Sap6. Using these antisera, together with sap null mutants obtained by targeted mutagenesis, we could demonstrate a high production of Sap4, Sap5 and Sap6 by C. albicans cells after phagocytosis by murine peritoneal macrophages. Furthermore, a delta sap4,5,6 null mutant was killed 53% more effectively after contact with macrophages than the wild-type strain. These results support a role for Sap4 to Sap6 in pathogenicity.