Antifungal prophylaxis in immunocompromised hosts

Clinicomycological overview of brain abscess in a tertiary care center: A 38 year retrospection: Fungal brain abscess

INTRODUCTION

Brain abscesses (BA) form approximately 8% of intracranial masses in developing and 1-2% in western countries. Fungal BA (FBA) are aggressive and represent a catastrophic manifestation compared to protozoan and bacterial BA. Diagnosis of FBA is rare and usually done postmortem.

OBJECTIVES

The present retrospective study analyses the clinico-mycological aspects of FBA presented to our neurosurgical services over a period of 38 years, from January 1979 to April 2017.

MATERIALS AND METHODS

Patients diagnosed as definitive cases of FBA were included in the study. Clinico- demographic and microbiological data were collected from medical records. BA pus was examined for fungal etiology using standard microbiological procedures.

RESULTS

During the period of 38 years out of total 2,916 brain abscesses, 29 cases of FBA were diagnosed with an overall incidence rate of 0.99% per year. Cladophialophora bantiana (44%) was the most predominant isolate followed by Aspergillus spp and others. Male preponderance was seen with a male:female ratio of 4.8:1. There was no predilection for any age group. Headache, limb weakness and fever were the most common presentations. Amphotericin B was given in 44.8% of cases. Craniotomy with excision (48.2%) was the predominant surgical management. Outcome was fatal in 62% of the cases.

CONCLUSION

Neurotropic C. bantiana is the predominant isolate causing fungal brain abscess. The incidence and trends of fungi causing brain abscess do not show significant change. Young immunocompetent outdoor working males were predominantly susceptible to fungal infection. Advance in the diagnostic modalities show promising in diagnosis of FBA. High index of suspicion with early diagnosis, prompt antifungal therapy and aggressive surgical management is required as FBA are associated with high mortality rate.

Invasive fungal infections and antifungal therapies in solid organ transplant recipients

This manuscript will review the risk factors, prevalence, clinical presentation, and management of invasive fungal infections (IFIs) in solid organ transplant (SOT) recipients. Primary literature was obtained via MEDLINE (1966-April 2007) and EMBASE. Abstracts were obtained from scientific meetings or pharmaceutical manufacturers and included in the analysis. All studies and abstracts evaluating IFIs and/or antifungal therapies, with a primary focus on solid organ transplantation, were considered for inclusion. English-language literature was selected for inclusion, but was limited to those consisting of human subjects. Infectious complications following SOT are common. IFIs are associated with high morbidity and mortality rates in this patient population. Determining the best course of therapy is difficult due to the limited availability of data in SOT recipients. Well-designed clinical studies are infrequent and much of the available information is often based on case-reports or retrospective analyses. Transplant practitioners must remain aware of their therapeutic options and the advantages and disadvantages associated with the available treatment alternatives.

A prospective randomized trial of itraconazole vs fluconazole for the prevention of fungal infections in patients with acute leukemia and hematopoietic stem cell transplant recipients

Fluconazole antifungal prophylaxis is standard care in allogeneic hematopoietic stem cell transplant (HSCT) recipients, but this drug lacks anti-Aspergillus activity, the primary cause of invasive fungal infection (IFI) in many transplantation centers. We performed a randomized trial to compare itraconazole vs fluconazole, for prevention of IFIs in patients with acute leukemia (AL) and HSCT recipients. One hundred and ninety-five patients were randomly assigned to either fluconazole or itraconazole antifungal prophylaxis, after stratification into high-risk and low-risk groups. Antifungal prophylaxis was started at the beginning of chemotherapy and continued until resolution of neutropenia, or until amphotericin B treatment was started. IFI occurred in 11 (11%) of itraconazole, and in 12 (12%) fluconazole recipients. Invasive candidiasis (IC) developed in two (2%) itraconazole and one (1%) fluconazole recipients, while invasive aspergillosis (IA) developed in nine (9%) itraconazole and 11(11%) fluconazole recipients. There was no difference in the incidence of total IFI, IC and IA between the two study arms. However, there was a nonsignificant trend towards reduced mortality among patients who developed IA while receiving itraconazole prophylaxis (3/9=33% vs 8/11=73%, P=0.095).

Fungal infections associated with HIV infection

Oral candidiasis is perhaps the commonest infection seen in HIV disease. The aim of this workshop was to provide a sketch of the multifarious aspects of the disease from a global perspective. To this end the panellists addressed issues such as the virulence of Candida, emergence of antifungal resistance, management of candidiasis and other exotic, oral mycotic diseases. An all-pervasive theme was the dramatic differences in the management of fungal infections consequential to the availability (or the lack) of anti-HIV drugs in the developed and the developing world. Further, the social stigmata associated with the HIV disease in many developing regions in Africa and Asia appears to modify the therapeutic strategies. Additionally, the lesser-known regional variations in the disease manifestations and therapeutic approaches were stark. Further work is direly needed to address these issues.

Intravenous itraconazole followed by oral itraconazole in the treatment of invasive pulmonary aspergillosis in patients with hematologic malignancies, chronic granulomatous disease, or AIDS

The pharmacokinetics, efficacy, and safety of intravenous (iv) itraconazole (2 days at 400 mg/day, 12 days at 200 mg/day), followed by 12 weeks of oral capsules (400 mg/day) were studied in 31 immunocompromised patients with pulmonary invasive aspergillosis. All patients received iv itraconazole (median duration, 14 days), and 26 then received oral itraconazole (median duration, 78.5 days). After receiving iv itraconazole, concentrations increased rapidly, with trough plasma levels > or =250 ng/mL in 91% of patients and in all patients by day 7. Concentrations > or =500 ng/mL were observed in 64% of patients by day 2. Mean trough concentrations after 2 and 14 days were 670 and 850 ng/mL, respectively. Therapeutic levels were maintained after switching to oral capsules. A complete or partial response was seen at the last on-treatment assessment in 15 (48%) of 31 patients, with 6 (19%) showing stable disease. Itraconazole was well tolerated, with no unexpected effects. Overall iv/oral itraconazole was safe and effective in invasive aspergillosis.

Early tooth loss due to cyclic neutropenia: long-term follow-up of one patient

In young patients with abnormal loosening of teeth and periodontal breakdown, dental professionals should consider a wide range of etiological factors/diseases, analyze differential diagnoses, and make appropriate referrals. The long-term oral and dental follow-up of a female patient diagnosed in early infancy with cyclic neutropenia is reviewed, and recommendations for care are discussed.

Regulation of Candida albicans growth and adhesion by saliva

To examine the local regulation of oral Candida albicans growth, we examined non-stimulated and stimulated salivary flow rates (SFRs) and the C. albicans growth and adhesion inhibitory activities of saliva in 60 patients with oral candidiasis (divided into two groups: 25 patients with oral candidiasis only (group OC) and 35 patients with oral candidiasis and systemic diseases (group CS)) and 30 healthy control subjects. Both non-stimulated and stimulated SFRs in patients, especially in group CS; were decreased in comparison with those in the healthy control subjects. The levels of secretory immunoglobulin A (sIgA) in group OC and group CS and the lactoferrin level in group CS were decreased as compared with those in control individuals, although there were no differences in transferrin and total secretory component (SC) levels between the three groups. The secretion amounts (microg/min) of these proteins were statistically significantly decreased in the patients, especially in group CS. Saliva from the patients showed a lesser inhibitory effect on C. albicans growth and adhesion to HeLa cells than did saliva from the control subjects. In addition, polymorphonuclear leukocytes (PMNs) in patients' saliva generated smaller amounts of superoxide than did those in control subjects' saliva, and phagocytic and C. albicans killing activities were suppressed in the patients. These results indicate that the decreases in SFR, secretion of antimicrobial proteins in saliva, and salivary PMN activity are risk factors for oral candidiasis associated with aging and systemic diseases.

A randomized controlled trial of itraconazole versus fluconazole for the prevention of fungal infections in patients with haematological malignancies. U.K. Multicentre Antifungal Prophylaxis Study Group

Fluconazole is widely used as antifungal prophylaxis but it is ineffective against Aspergillus. Itraconazole has a broader spectrum of activity but the capsules give erratic bioavailability in neutropenic patients. We compared itraconazole oral solution (which has an improved pharmacokinetic profile) with fluconazole for antifungal prophylaxis. Adults with haematological malignancies receiving chemotherapy or bone marrow transplants were randomly allocated 5 mg/kg/d itraconazole (itra) solution (288 episodes) or 100 mg fluconazole suspension (flu) (293 episodes) from before the onset of neutropenia until neutrophil recovery or suspected fungal infection. Outcomes were assessed by independent reviewers unaware of the prophylaxis allocation. More proven systemic fungal infections occurred in flu (Aspergillus four, Candida tropicalis one, C. krusei one) than itra (C. albicans one) and more of these were fatal (four versus nil). This difference reached statistical significance when first study episodes were considered separately (six flu versus nil itra, P = 0.03). Significantly more deaths of presumed fungal origin occurred in flu than itra (seven versus nil, P = 0.024). There were significantly more cases of proven aspergillosis in flu than itra (six versus nil, P = 0.038, 5/6 cases were fatal) if those occurring outside the study period are included. Significantly more patients receiving flu required amphotericin B (58 v 39, P = 0.043) but this may have been affected by the fact that the study was not blinded. There were 11 proven mucosal candidal infections in flu and four in itra. Itraconazole solution and fluconazole provide effective prophylaxis against Candida but itraconazole affords greater protection against fatal aspergillosis.

The presence of an R467K amino acid substitution and loss of allelic variation correlate with an azole-resistant lanosterol 14alpha demethylase in Candida albicans

Azole resistance in the pathogenic yeast Candida albicans is an emerging problem in the human immunodeficiency virus (HIV)-infected population. The target enzyme of the azole drugs is lanosterol 14alpha demethylase (Erg16p), a cytochrome P-450 enzyme in the biosynthetic pathway of ergosterol. Biochemical analysis demonstrates that Erg16p became less susceptible to fluconazole in isolate 13 in a series of isolates from an HIV-infected patient. PCR-single-strand conformation polymorphism (PCR-SSCP) analysis was used to scan for genomic alterations of ERG16 in the isolates that would cause this change in the enzyme in isolate 13. Alterations near the 3' end of the gene that were identified by PCR-SSCP were confirmed by DNA sequencing. A single amino acid substitution (R467K) that occurred in isolate 13 was identified in both alleles of ERG16. Allelic differences within the ERG16 gene, in the ERG16 promoter, and in the downstream THR1 gene were eliminated in isolate 13. The loss of allelic variation in this region of the genome is most likely the result of mitotic recombination or gene conversion. The R467K mutation and loss of allelic variation that occur in isolate 13 are likely responsible for the azole-resistant enzyme activity seen in this and subsequent isolates. The description of R467K represents the first point mutation to be identified within ERG16 of a clinical isolate of C. albicans that alters the fluconazole sensitivity of the enzyme.

Improvement of bioavailability of the HIV protease inhibitor SC-52151 in the beagle dog by coadministration of the CYP3A4 inhibitor, ketoconazole

1. SC-52151, an HIV protease inhibitor, is mainly metabolized by CYP3A4 and is poorly bioavailable after oral administration. After i.v. administration of SC-52151 to the female beagle dog (2.5 mg/kg), SC-52151 was rapidly eliminated in plasma with an elimination half-life of about 1 h, a plasma clearance of 44 ml/min/kg and an apparent steady-state volume distribution of 2.2 litre/kg. The high value of plasma clearance of SC-52151 suggests an extensive hepatic first-pass metabolism since SC-52151 is highly protein bound and does not partition itself into red blood cells. 2. The extensive hepatic first-pass metabolism was reduced by coadministration of a CYP3A4 inhibitor, ketoconazole. 3. Dogs were dosed daily with ketoconazole at dose of 100 mg ketoconazole per dog (approximately 10 mg/kg) for 5 days prior to the initiation of coadministration of SC-52151 for 15 days. The doses used for SC-52151 was 0, 60 and 120 mg SC-52151/kg/day (divided t.i.d., 8-h dosing interval). Coadministration of ketoconazole improved the bioavailability of SC-52151 from 4.1 to 9.6% and also improved the Cmax of SC-52151 from 0.41 to 0.83 microgram/ml. 4. Although the absolute bioavailability of SC-52151 was still low (approximately 10%), the Cmax and AUC achieved in this study were satisfactory for conducting chronic toxicology studies. No toxicity associated with the coadministration of ketoconazole was evident. Results from this study suggest that coadministration of ketoconazole might be a practical approach to increase the exposure of SC-52151 in both preclinical and clinical studies.

Stable azole drug resistance associated with a substrain of Candida albicans from an HIV-infected patient

Oral candidiasis is one of the earliest and most frequent complications of a failing immune system in HIV-infected individuals. For several years, oral candidiasis has been treated effectively with azole drugs, the one most frequently used is fluconazole. Unfortunately, extensive use of the drug for treatment and prophylaxis has led to treatment failure in an increasing number of patients. In most of these cases, strains of C. albicans isolated from the infection are less susceptible to fluconazole. The development of azole resistance in strains of C. albicans has been studied biochemically and more recently with molecular techniques. One excellent example of the development of azole resistance in C. albicans has been documented in a series of 17 C. albicans isolates from a single patient over a 2-year period. During this time, the patient experienced 14 episodes of oral candidiasis and was treated with increasing doses of fluconazole. Molecular and biochemical analyses confirms that the isolates are the same strain of C. albicans and that the resistance in these isolates is stable over 600 generations, suggesting that the changes in this strain are genetic in nature. In addition, the development of resistance is correlated with the identification of a substrain or variant of the original strain, as identified by restriction fragment length polymorphism (RFLP) analysis with the moderately repetitive probe, Ca3. The analysis of this series of isolates demonstrates that azole drug resistance is associated with several small genetic changes, each of which contributes to the overall resistance of the strain. Clearly, continual use of azole drugs by a patient can select for genetic changes that render oral candidiasis refractory to treatment.

Fatal diffuse invasive gastrointestinal candidiasis masking as ileus after bone marrow transplantation

High-dose cytotoxic chemotherapy has increased the incidence of candidal infections that make neutropenic patients very sick and may kill them. We report fatal invasive candidiasis involving the entire alimentary tract after autologous bone marrow transplantation in a young woman with breast cancer. Illustrated are the significance of fungal infections in this patient population, the potential for Candida albicans to invade the entire gastrointestinal tract, and the potential role of endoscopy in the early diagnosis of these often catastrophic infections. We also suggest that diffuse, invasive candidiasis should be considered in the differential diagnosis of ileus in the immunocompromised patient.

Primary care of the HIV patient: standard practice and new developments in the era of managed care

It is easy when taking care of the patient with AIDS to lose sight of the whole person and become focused on the details of micromanagement, distracted by the array of new therapies, and overwhelmed by the financial risks of the disease. It is therefore critical that a healing and respectful relationship is developed with patients and they are engaged in the decisions regarding their care. Physicians must also continue the search for new therapies and struggle to ensure that patients have access to state-of-the-art treatment. In this, the primary care physician plays a critical role, through identifying study centers, becoming an investigator in expanded access programs, and using referrals to clinical trials to provide new therapies to patients and improve understanding of HIV treatment. Finally, quality of life must be at the forefront of physicians' medical conscience. Ultimately, the physician must know when the best treatment he of she can offer is the assurance of a dignified and comfortable death.

Amphotericin B infusion-related toxicity: comparison of two- and four-hour infusions

OBJECTIVE

To investigate the influence of infusion duration on infusion-related adverse effects (IRAEs) associated with prophylactic or treatment regimens of amphotericin B in patients with leukemia/bone marrow transplant (BMT).

DESIGN

Randomized, double-blind, 2-arm, complete crossover, prospective clinical trial.

SETTING

A university-affiliated tertiary care teaching hospital.

PARTICIPANTS

The study population consisted of 25 consecutive patients with leukemia/BMT who received 162 prophylactic regimen infusions and 169 treatment regimen infusions of amphotericin B via a central line. Prior to each infusion all patients received a parenteral IRAE prophylaxis regimen of diphenhydramine 25 mg and hydrocortisone 25 mg. No test doses or incremental amphotericin B doses were administered. Patients were monitored closely for IRAEs, which were documented by using a standardized data collection form.

MAIN OUTCOME MEASURES

The incidence and nature of IRAEs during a 6-hour monitoring period following the initiation of each infusion was measured. Patients served as their own controls. IRAEs were compared according to infusion duration and therapeutic indication.

RESULTS

Three hundred and thirty-one 2- and 4-hour amphotericin B infusions were administered. We found no difference between 2- and 4-hour infusions in the incidence and severity of IRAEs, including overall events (29% of 166 2-hour infusions vs. 25% of 165 4-hour infusions), chill scores (8% of 166 2-hour infusions vs. 7% of 165 4-hour infusions; highest score 7 vs. 6), nausea and vomiting (7% vs. 12%; highest score 4 in both groups), fever (3% vs. 2%), highest temperature increase (2.4 vs. 1.6 degrees C), systolic hypotension (6% vs. 2%), greatest decrease from baseline (40 vs. 62 mm Hg), diastolic hypotension (5% vs. 3%), and greatest decrease (30 vs. 28 mm Hg) (p > 0.05). Overall, IRAEs were less common in prophylactic treatment regimens (35 events [22%] in 162 infusions) than in treatment regimens (55 events [32%] in 169 infusions) (p < 0.05).

CONCLUSIONS

This study demonstrates that patients with leukemia/BMT without myocardial or renal dysfunction who receive hydrocortisone and diphenhydramine as premedications can tolerate 2-hour central line infusions of prophylactic or treatment regimens of amphotericin B as well as 4-hour infusions.

Comparison of fluconazole with oral polyenes in the prevention of fungal infections in neutropenic patients. A prospective, randomized, single-center study

The goal of this prospective randomized single-center study was the comparison of safety and efficacy of high-dose oral/intravenous fluconazole (400 mg daily) (group A) with oral nystatin plus miconazole inhalations (group B) in the prevention of fungal infections on a hemato-oncological isolation Ward. Of 157 patients admitted to the isolation ward during the study period only 90 (57%) were eligible for randomization; 22 (14%) had a fungal infection at admission. Of the 90 randomized patients, 89 were evaluable, 43 in group A and 46 in group B. The age, sex, diagnosis, planned therapy and risk factors for fungal infections at admission as well as the duration of neutropenia were in the same proportions in both groups. Oral thrush and mucocutaneous candidiasis were prevented in all patients of both groups, and 29 patients (32%: 17 in group A, 12 in group B) were discharged after successful prophylaxis (NS). Empiric amphotericin B was given according to predetermined criteria to 45 patients (51%: 23 group A, 22 group B; NS). Fluconazole significantly delayed the time before the start of intravenous amphotericin B. It was begun after a median of 10 days (0-45 days, range) of neutropenia below 0.5 x 10(9) granulocytes/l in group A and 7.5 days (0-26, range) in group B (P < 0.05). The duration of successful prophylaxis was significantly longer in group A (26 days median) than in group B (21 days, median) (P < 0.05). Systematic fungal infection was documented in 3 patients (1 group A, 2 group B; NS).

A review of oral fungal infections and appropriate therapy

Dental health care providers must recognize oral fungal pathogens that often are markers for early signs of immune deterioration. After accurate identification, appropriate therapy can be initiated. Predisposing factors for development of oral fungal infections, identification of oral fungal infections, treatment options and their relative costs are reviewed.