Hematopoietic growth factors in cancer patients with invasive fungal infections

The role of fungi in diseases of the nose and sinuses

BACKGROUND

Human exposure to fungal elements is inevitable, with normal respiration routinely depositing fungal hyphae within the nose and paranasal sinuses. Fungal species can cause sinonasal disease, with clinical outcomes ranging from mild symptoms to intracranial invasion and death. There has been much debate regarding the precise role fungal species play in sinonasal disease and optimal treatment strategies.

METHODS

A literature review of fungal diseases of the nose and sinuses was conducted.

RESULTS

Presentation, diagnosis, and current management strategies of each recognized form of fungal rhinosinusitis was reviewed.

CONCLUSION

Each form of fungal rhinosinusitis has a characteristic presentation and clinical course, with the immune status of the host playing a critical pathophysiological role. Accurate diagnosis and targeted treatment strategies are necessary to achieve optimal outcomes.

Recommendations for the treatment of established fungal infections

Evidence-based guidelines for the treatment of established fungal infections in the adult haematology/oncology setting were developed by a national consensus working group representing clinicians, pharmacists and microbiologists. These updated guidelines replace the previous guidelines published in the Internal Medicine Journal by Slavin et al. in 2004. The guidelines are pathogen-specific and cover the treatment of the most common fungal infections including candidiasis, aspergillosis, cryptococcosis, zygomycosis, fusariosis, scedosporiosis, and dermatophytosis. Recommendations are provided for management of refractory disease or salvage therapies, and special sites of infections such as the cerebral nervous system and the eye. Because of the widespread use newer broad-spectrum triazoles in prophylaxis and empiric therapy, these guidelines should be implemented in concert with the updated prophylaxis and empiric therapy guidelines published by this group.

[New medications for treatment of systemic mycoses]

The past few years have seen the advent of several new antifungal agents. The echinocandin, caspofungin, has greatly expanded the antifungal armamentarium by providing a cell wall-active agent with candidacidal activity as well as demonstrated clinical efficacy in the therapy of aspergillosis refractory to available therapy. In addition, in clinical trials, caspofungin exhibited efficacy comparable to amphotericin B for invasive and/or fluconazole-resistant Candida infections. According to a randomised trial, voriconazole has added a significantly improved therapeutic option for primary therapy of invasive aspergillosis. Additionally, voriconazole may be used successfully as salvage therapy for other fungal infections, i.e. cryptococcosis. Despite the advances offered by each of these drugs, the morbidity and mortality associated with invasive fungal infections remains high. Considering the adverse effects of the available antifungal agents and the considerable costs for their application, meaningful clinical trials for a precise indication in different clinical situations are urgently needed.

Treatment of fungal infections in hematology and oncology--guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

The Infectious Diseases Working Party of the German Society of Haematology and Oncology presents their guidelines for the treatment of fungal infections in patients with hematological and oncological malignancies. These guidelines are evidence-based, considering study results, case reports and expert opinions, using the evidence criteria of the Infectious Diseases Society of America (IDSA). The recommendations for major fungal complications in this setting are summarized here. The primary choice of therapy for chronic candidiasis should be fluconazole, reserving caspofungin or amphotericin B (AmB) for use in case of progression of the Candida infection. Patients with candidemia (except C. krusei or C. glabrata) who are in a clinically stable condition without previous azole prophylaxis should receive fluconazole, otherwise AmB or caspofungin. Voriconazole is recommended for the first-line treatment of invasive aspergillosis. The benefit of a combination of AmB and 5-flucytosine has not been demonstrated except in patients with cryptococcal meningitis. Mucormycosis is relatively rare. The drug therapy of choice consists of AmB, desoxycholate or liposomal formulation, in the highest tolerable dosage. Additional surgical intervention has been shown to achieve a lower fatality rate than with antifungal therapy alone. The role of interventional strategies, cytokines/G-CSF, and granulocyte transfusions in invasive fungal infections are further reviewed. These guidelines offer actual standards and discussions on the treatment of oropharyngeal and esophageal candidiasis, invasive candidiasis, cryptococcosis and mould infections.

The Pathophysiology and Treatment of Candida Sepsis

Sepsis can occur during disseminated candidiasis, but its pathogenesis differs from that caused by typical prokaryotic pathogens. Complex interactions between defects in host defense and "relative" virulence factors expressed by Candida lead to dissemination of the saprophyte to parenchymal organs, and subsequently to onset of multiorgan failure. This review focuses first on the pathophysiology of Candida sepsis, detailing current understanding of host-pathogen interactions. We then consider the choice of antifungal and supportive treatments.

Early investigation and initiation of therapy for invasive pulmonary aspergillosis in leukaemic and bone marrow transplant patients

Invasive fungal infections are an increasingly common problem in cancer patients and in other vulnerable groups. Invasive pulmonary aspergillosis (IPA) in the neutropenic host presents particular challenges in terms of diagnosis and therapy. Against the background of a recognized problem of invasive aspergillosis in haematology/oncology patients treated at the Christie Hospital, we undertook a prospective study in patients at risk for IPA. The aim of the study was to improve outcome by using the linked strategies of first, early diagnosis, and secondly, early aggressive therapy with a lipid-associated formulation of amphotericin B, amphotericin B colloidal dispersion ('Amphocil'). Early investigation comprised the use of high-resolution computerized tomography scanning of the thorax and fibreoptic bronchoscopy to obtain bronchoalveolar lavage specimens, processed using conventional detection and culture methods. Using this approach, the incidence of proven or probable IPA in patients with acute leukaemia was 9%. Prompt initiation of amphotericin B colloidal dispersion therapy led to a successful outcome in 11 of 13 patients, compared with a mortality of 100% in historical controls.

The potential for monocyte-mediated immunotherapy during infection and malignancy--Part II: in vivo activation by exogenous cytokines and clinical applications

The monocyte system exhibits a range of immunological mechanisms that may be harnessed for therapeutic effect against infection and malignancy. The advent of novel therapies aimed at treating infection and malignancy is complemented by a resurgence of clinical interest in immunotherapeutic programmes to treat diseases by modification or direct augmentation of host immunity. Cytokines such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and IFN-gamma modulate the function of monocytes and have been used to experimentally probe the immunotherapeutic potential of monocytes against micro-organisms and malignancy. However, monocytes rarely act alone but communicate with other leukocytes involved in cell-mediated immunity. In particular monocytes cooperate with the T-helper (Th1 and Th2) sub-populations of peripheral lymphocytes. Moreover, sub-populations of monocytes, as identified by the co-expression of membrane-associated CD14 and CD16, have been shown to exist. At the preclinical level, this provides a unique opportunity to explore the effect of immunotherapeutic strategies on the function of monocyte sub-populations against infectious or malignant challenge and may allow immunotherapeutic strategies to be targeted towards specific monocyte sub-populations. Preclinical and clinical studies in human subjects suggest that GM-CSF and other cytokines such as IFN-gamma are the most promising biological response modifiers for augmenting monocyte-mediated immunity. In this review, the immunotherapeutic potential of the monocyte system will be discussed in the context of combating microbial and malignant disease.

Aspergillus fumigatus and aspergillosis

Aspergillus fumigatus is one of the most ubiquitous of the airborne saprophytic fungi. Humans and animals constantly inhale numerous conidia of this fungus. The conidia are normally eliminated in the immunocompetent host by innate immune mechanisms, and aspergilloma and allergic bronchopulmonary aspergillosis, uncommon clinical syndromes, are the only infections observed in such hosts. Thus, A. fumigatus was considered for years to be a weak pathogen. With increases in the number of immunosuppressed patients, however, there has been a dramatic increase in severe and usually fatal invasive aspergillosis, now the most common mold infection worldwide. In this review, the focus is on the biology of A. fumigatus and the diseases it causes. Included are discussions of (i) genomic and molecular characterization of the organism, (ii) clinical and laboratory methods available for the diagnosis of aspergillosis in immunocompetent and immunocompromised hosts, (iii) identification of host and fungal factors that play a role in the establishment of the fungus in vivo, and (iv) problems associated with antifungal therapy.