Comparison of amphotericin B with fluconazole in the treatment of acute AIDS-associated cryptococcal meningitis. The NIAID Mycoses Study Group and the AIDS Clinical Trials Group

Antifungal therapy: lessons learned over the past 27 years

As principal investigator of the National Institute of Allergy and Infectious Diseases-sponsored Mycoses Study Group for the past 27 years, I have been fortunate to play a role in the many advances in the field of clinical mycology and antifungal therapy. For the Finland lecture, I will briefly discuss the development of the Mycoses Study Group, provide an overview of the currently available antifungal agents, and describe advances and lessons related to the treatment and management of cryptococcal meningitis (the most common form of fungal meningitis), 3 important endemic mycoses (namely, blastomycosis, histoplasmosis, and coccidioidomycosis), candidemia and invasive candidiasis (the most common forms of nosocomial fungal disease), and invasive aspergillosis (the most common form of invasive mould disease). My concluding remarks will address the increasing hurdles and challenges, as well as the rewards, facing investigators who focus on clinical trials.

Pulmonary cryptococcosis: comparison of clinical and radiographic characteristics in immunocompetent and immunocompromised patients

STUDY OBJECTIVES

We compared the clinical characteristics and imaging findings between immunocompetent and immunocompromised patients in whom pulmonary cryptococcosis had been diagnosed to define the role of serum cryptococcal antigen (sCRAG) and radiographs during a follow-up period of up to 1 year.

DESIGN

Retrospective cohort study.

SETTING

University hospital.

PATIENTS

The clinical records, chest radiographs, and CT scan findings of 13 immunocompetent and 16 immunocompromised patients with a diagnosis based on cerebrospinal fluid (CSF) culture, sCRAG titers, and cytologic or histologic confirmation of the presence of pulmonary cryptococcosis were reviewed during the course of the study. Two thoracic radiologists reviewed chest radiographs and CT scans for morphologic characteristics and the distribution of parenchymal abnormalities, and a final reading was reached by consensus. The correlation between serial radiographs and sCRAG titers was examined in 9 immunocompetent and 10 immunocompromised patients.

MEASUREMENTS

Serum or CSF cryptococcal antigen.

RESULTS

The most common clinical symptom was cough, which was present in 24 patients (82.8%). Pulmonary nodules were the most frequent radiologic abnormality. Cavitation within nodules and parenchymal consolidation were significantly less common in immunocompetent patients compared to immunocompromised patients (p = 0.02 and p = 0.05, respectively). Immunocompromised patients tended to have a larger extent of pulmonary involvement than immunocompetent patients, the changes seen on their serial radiographs were more variable, and their corresponding sCRAG titers were higher (> 1:256). In the immunocompetent patients, the radiographic characteristics of lesions usually improved with a corresponding decrease in sCRAG titers over time.

CONCLUSIONS

Our study suggests that pulmonary cryptococcosis usually follows a benign clinical course in immunocompetent patients. Immunocompromised patients often undergo an evolution to cavitary lesions that represent a more aggressive disease nature. Serial radiographic changes and changes in sCRAG titers reliably reflect disease progression and the response to therapy.

Central nervous system infections in the neurointensive care unit

Central nervous system (CNS) infections are frequently encountered at the primary care level, in emergency rooms, medical wards, and intensive care units. Advances in immunization techniques and aggressive prevention campaigns have had an impact on the worldwide incidence of community-acquired meningitis, limiting this disease to the adult population. In general, a high index of suspicion is required for the diagnosis, but special attention should be given to the immunocompromised host and post-neurosurgical patient in whom the clinical presentation may be nonspecific. Once the diagnosis is made, broad-spectrum antimicrobials should be administered, followed by diagnostic testing, and targeted antibiotic therapy. Current guidelines for the treatment of meningitis are clinically effective but are not based on randomized, prospective, controlled trials. Despite current therapies, the morbidity of CNS infections is still devastating. Recent trials of the use of corticosteroids as coadjuvants of antibiotic therapy showed promising results and decrease in the morbidity associated with bacterial and tuberculous meningitis. Additional neuroprotective alternatives should be the focus of future research. Similarly, guidelines for the diagnosis and management of post-neurosurgical procedure meningitis and ventriculostomy-related infections are needed.

Prevention of cryptococcosis in HIV-infected patients with limited access to highly active antiretroviral therapy: evidence for primary azole prophylaxis

Despite advances in the treatment of HIV disease, the incidence and mortality of invasive cryptococcal disease remain significant. A matched, case-control study was performed to examine the impact of highly active antiretroviral therapy (HAART) and azole use on the incidence of invasive cryptococcal disease in HIV-infected patients. The study was performed at a metropolitan hospital with a large indigent population and an incidence of seven cases of cryptococcal disease per 1000 persons with AIDS. Bivariate analysis, matched on CD4 count, revealed that both HAART use [odds ratio (OR) 0.43; 95% confidence interval (CI) 0.23-0.99] and azole use (OR 0.14; 95% CI 0.06-0.34) had a protective effect. Conditional logistic regression stratified on CD4 lymphocyte count revealed a protective role for azole use (OR 0.15; 95% CI 0.06-0.40) but not for HAART use (OR 0.47; 95% CI 0.18-1.26). Of note, the prevalence of HAART use was low in both cases and controls, with only 12% of cases and 23% of controls on HAART. The results of this study support previous evidence that azole use prevents invasive cryptococcal disease. Although current guidelines for the prophylaxis of opportunistic infections do not suggest routine prophylaxis for cryptococcal infection, this issue should be reconsidered, especially in populations that have a low prevalence of HAART use.

Chronic Meningitis in Thailand

The charts of 114 consecutive patients with chronic meningitis admitted to a general hospital in Bangkok, Thailand, between 1993 and 1999 were retrospectively reviewed. The most common causative agents were Cryptococcus neoformans (54%) and Mycobacterium tuberculosis (37%). HIV and other underlying diseases had a major impact on the presentation of chronic cryptococcal meningitis patients. Compared to HIV-negative cryptococcal meningitis patients (21%), HIV-positives (79%) had a significantly lower incidence of focal signs (p = 0.02), hydrocephalus (p = 0.03) and seizures (p = 0.001) during hospital stay, furthermore, a lower leucocyte level, a significantly higher glucose level (p = 0.02) and a lower protein level (p = 0.03) in the first cerebrospinal fluid examination. Of the 43 patients with chronic tuberculous meningitis, only 3 were HIV positive. Focal neurologic deficits were found more frequently in tuberculous meningitis patients (p = 0.001) when compared to cryptococcal meningitis patients without HIV. Cerebral infarction on cerebral CT was indicative of tuberculous meningitis. Cryptococcal meningitis patients with HIV infection had a worse outcome compared to non-AIDS patients. Advanced stage of the disease on admission, decreased level of consciousness prior to and on the admission day and raised intracranial pressure above 40 cm H(2)O at any given time were predictive of a poor outcome in tuberculous meningitis patients.

Antifungal Management Practices and Evolution of Infection in Organ Transplant Recipients with Cryptococcus Neoformans Infection

BACKGROUND

Therapeutic practices for Cryptococcus neoformans infection in transplant recipients vary, particularly with regards to antifungal agent employed, and duration of therapy. The risk of relapse and time to recurrence is not known. We assessed antifungal treatment practices for cryptococcosis in a cohort of prospectively followed organ transplant recipients.

METHODS

The patients comprised 83 transplant recipients with cryptococcosis followed for a median of 2.1 and up to 5.2 years.

RESULTS

Patients with central nervous system infection (69% vs. 16%, P = 0.00001), disseminated infection (82.7% vs. 20%, P = 0.00001), and fungemia (29% vs. 8%, P = 0.046) were more likely to receive regimens containing amphotericin B than fluconazole as primary therapy. The use of fluconazole, on the other hand, was more likely for infection limited to the lungs (64% vs. 14%, P = 0.00002). Survival at 6 months tended to be lower in patients whose CSF cultures at 2 weeks were positive compared to those whose CSF cultures were negative (50% vs. 91%, P = 0.06). Maintenance therapy was employed in 68% (54/79) of the patients who survived >3 weeks. The median duration of maintenance therapy was 183 days; 55% received maintenance for > or = 6 months and 25% for >1 year. Relapse was documented in 1.3% (1/79) of the patients.

CONCLUSIONS

A majority of the organ transplant recipients with cryptococcosis receive maintenance antifungal therapy for 6 months with low risk of relapse. These data can assist in trials to assess the optimal therapeutic approach and duration of therapy for cryptococcosis in transplant recipients.

The use of unequal randomisation ratios in clinical trials: a review

OBJECTIVE

To examine reasons given for the use of unequal randomisation in randomised controlled trials (RCTs).

MAIN MEASURES

Setting of the trial; intervention being tested; randomisation ratio; sample size calculation; reason given for randomisation.

METHODS

Review of trials using unequal randomisation. DATABASES AND SOURCES: Cochrane library, Medline, Pub Med and Science Citation Index.

RESULTS

A total of 65 trials were identified; 56 were two-armed trials and nine trials had more than two arms. Of the two-arm trials, 50 trials recruited patients in favour of the experimental group. Various reasons for the use of unequal randomisation were given. Six studies stated that they used unequal randomisation to reduce the cost of the trial, with one screening trial limited by the availability of the intervention. Other reasons for using unequal allocation were: avoiding loss of power from drop-out or cross-over, ethics and the gaining of additional information on the treatment. Thirty seven trials papers (57%) did not state why they had used unequal randomisation and only 14 trials (22%) appeared to have taken the unequal randomisation into account in their sample size calculation.

CONCLUSION

Although unequal randomisation offers a number of advantages to trials the method is rarely used and is especially under-utilised to reduce trial costs. Unequal randomisation should be considered more in trial design especially where there are large differences between treatment costs.

Combination therapy for invasive mycoses: evaluation of past clinical trial designs

BACKGROUND

Despite the availability of new antifungals, single-agent therapy frequently falls short of high cure rates. Combination therapy offers potentially higher cure rates, especially for resistant organisms. In vitro studies and experimental animal models have provided conflicting data.

METHODS

Retrospective, randomized, controlled clinical studies were reviewed.

RESULTS

Results indicate a clear advantage for polyene and flucytosine combination therapy in cryptococcal meningitis and a possible advantage for combination amphotericin B and fluconazole for candidemia. Unfortunately, the few studies published have been flawed by design problems that have compromised the determination of outcome. Study review allows investigators the opportunity to design future studies to ensure optimal evaluation of efficacy.

CONCLUSION

Combination antifungal therapy is advantageous in cryptococcal diseases and may have a role in the treatment of invasive candidiasis. The greatest potential exists for combination therapy against aspergillosis and resistant fungi in patients with refractory mycotic disease who experience failure of monotherapy.

Activity of posaconazole in the treatment of central nervous system fungal infections

OBJECTIVES

A multinational, multicentre, open-label clinical trial was conducted to evaluate the safety and efficacy of posaconazole, an extended-spectrum triazole antifungal agent, in subjects with invasive fungal infections who had refractory disease or who were intolerant of standard antifungal therapy. In this subanalysis, we report on those subjects in this trial who had a fungal infection that involved the CNS.

METHODS

Subjects received posaconazole oral suspension 800 mg/day in divided doses for up to 1 year; however, subjects could receive additional therapy as part of a treatment-use extension protocol. A blinded, third-party data review committee determined subject eligibility and outcome.

RESULTS

Of the 330 subjects who enrolled in the study, 53 had infections of the CNS, of which 39 were considered evaluable for efficacy. Most had refractory disease (37 of 39) and underlying HIV infection (29 of 39). Twenty-nine subjects had cryptococcal infections, and 10 had infections caused by other fungal pathogens [Aspergillus spp. (four), Pseudallescheria boydii (two), Coccidioides immitis (one), Histoplasma capsulatum (one), Ramichloridium mackenziei (one), and Apophysomyces elegans plus a Basidiomycetes sp. (one)]. Successful outcomes were observed in 14 of 29 (48%) subjects with cryptococcal meningitis and five of 10 (50%) subjects with CNS infections due to other fungal pathogens. Posaconazole was well tolerated.

CONCLUSIONS

These data suggest that posaconazole, as an oral medication, has clinical activity against fungal infections of the CNS and may provide a valuable alternative to parenteral therapy in patients failing existing antifungal agents.

HIV-associated tuberculosis and cryptococcosis in resource-limited settings

Tuberculosis (TB) and cryptococcosis are common infectious complications in HIV in resource-limited settings and contribute substantial morbidity and mortality. The increasing access to highly active antiretroviral treatment (HAART) has invited numerous challenges such as timing of HAART, cotreatment (drug dosages and interaction), immune reconstitution syndromes, and withdrawal of chemoprophylaxis. Numerous small studies propose the feasibility of concomitant TB/HIV treatment that needs to be confirmed in large, randomized trials. Treatment of acute cryptococcocal meningo-encephalitis with amphoterecin B is fraught with logistic problems in resource-limited settings. An effective safe dose of fluconazole as monotherapy needs to be determined in phase II studies. Current management guidelines extrapolated from developed countries may not necessarily apply and need validation in resource-limited settings.

The use of ventriculoperitoneal shunts for uncontrollable intracranial hypertension without ventriculomegally secondary to HIV-associated cryptococcal meningitis

BACKGROUND

The risks associated with implanting a cerebrospinal fluid (CSF) shunt in immunocompromised patients with ongoing CSF infection have historically discouraged surgeons from implanting CSF shunts in patients with HIV and cryptococcal meningitis. However, this patient population often requires frequent lumbar punctures to manage elevated intracranial pressure (ICP) secondary to cryptococcal infection. To date, only 7 cases of ventriculoperitoneal (VP) shunting for the treatment of intracranial hypertension in patients with HIV-associated cryptococcal meningitis have been reported. Few of these reports have included outcomes more than 3 months postsurgery. It remains unclear if VP shunts are an effective long-term treatment of intracranial hypertension in this patient population.

CASE DESCRIPTIONS

Two patients with HIV/AIDS (CD4 counts of 8 and 81 cells/mm(3)) presented with altered mental status, visual changes, florid cryptococcal meningitis, and elevated ICP (>500 mm CSF) without evidence of hydrocephalus on computed tomography scan. Both patients experienced rapid reversal of symptoms with external lumbar CSF drainage, and remained lumbar drain-dependent after 2 weeks of amphotericin B and flucytosine therapy. Despite evidence of unresolved cryptococcal meningitis, each patient underwent implantation of a VP shunt without complication and was discharged on lifetime fluconazole therapy. They remained asymptomatic at 12 and 16 months after surgery without evidence of shunt infection or malfunction.

CONCLUSION

Patients with intracranial hypertension and HIV-associated cryptococcal meningitis who cannot tolerate cessation of external lumbar CSF drainage or frequent lumbar punctures may be considered for VP shunt placement despite severe immunosuppression and persistent CSF cryptococcal infection.

Phase I evaluation of the safety and pharmacokinetics of murine-derived anticryptococcal antibody 18B7 in subjects with treated cryptococcal meningitis

A promising approach to improving outcomes in patients with cryptococcal meningitis is to use adjunctive passive immunotherapy with a monoclonal antibody (MAb) directed against the capsular polysaccharide of Cryptococcus neoformans. This is the first application of MAb therapy for the treatment of a fungal disease in humans. We determined the safety and maximum tolerated dose of the murine anticryptococcal MAb 18B7 in a phase I dose-escalation study. The subjects were human immunodeficiency virus-infected patients who had been successfully treated for cryptococcal meningitis. Six dosing cohorts received MAb 18B7 at 0.01 to 2 mg/kg of body weight as a single infusion. Three patients each received 0.01, 0.05, 0.2, and 0.5 mg of MAb 18B7 per kg without significant adverse events. Four of the subjects who received the 1-mg/kg dose had mild study drug-associated toxicity, including transient nausea, vomiting, back pain, and urticarial rash. Two of the subjects who received 2 mg/kg developed drug-associated mild to moderate nausea, vomiting, chills, and myalgias. One of the subjects who received 2 mg/kg developed intracranial hypertension 10 weeks after MAb 18B7 administration. Serum cryptococcal antigen titers in the cohorts receiving doses of 1 and 2 mg/kg declined by a median of twofold at 1 week and a median of threefold at 2 weeks postinfusion, but the titers subsequently returned toward the baseline values by week 12. The half-life of MAb 18B7 in serum was approximately 53 h, while the MAb was undetectable in the cerebrospinal fluid of all patients. These data support the continued investigation of MAb 18B7 at a maximum single dose of 1.0 mg/kg.

Successful Use of Amphotericin B Lipid Complex in the Treatment of Cryptococcosis

The efficacy and renal safety of amphotericin B lipid complex (ABLC) injection were assessed in 106 patients with cryptococcal infection. Eighty-three patients (78%) had a central nervous system (CNS) infection. Of these patients, 20 initiated azole therapy concomitantly with ABLC therapy, and 7 had received prior azole therapy, which continued during administration of ABLC. Clinical response (cured or improved) was achieved in 67 (66%) of 101 patients whose results could be evaluated. Response rates were 65% (51/78) for patients with a CNS infection and 70% (16/23) for patients without a CNS infection. The response rate for patients with HIV infection was 58% (30/52). Response rates were 56% (19/34) for patients who were refractory to prior antifungal therapy, 65% (11/17) for patients who were intolerant of prior antifungal therapy, 60% (3/5) for patients with underlying renal disease who received prior antifungal therapy, 76% (25/33) for patients with underlying renal disease who did not receive prior antifungal therapy, and 73% (8/11) for patients with no renal disease who did not receive prior antifungal therapy. A mean serum creatinine level decrease of 0.02 mg/dL occurred. ABLC was an effective treatment for cryptococcal infection in immunocompromised patients.

Combination treatment of invasive fungal infections

The persistence of high morbidity and mortality from systemic fungal infections despite the availability of novel antifungals points to the need for effective treatment strategies. Treatment of invasive fungal infections is often hampered by drug toxicity, tolerability, and specificity issues, and added complications often arise due to the lack of diagnostic tests and to treatment complexities. Combination therapy has been suggested as a possible approach to improve treatment outcome. In this article, we undertake a historical review of studies of combination therapy and also focus on recent studies involving newly approved antifungal agents. The limitations surrounding antifungal combinations include nonuniform interpretation criteria, inability to predict the likelihood of clinical success, strain variability, and variations in pharmacodynamic/pharmacokinetic properties of antifungals used in combination. The issue of antagonism between polyenes and azoles is beginning to be addressed, but data regarding other drug combinations are not adequate for us to draw definite conclusions. However, recent data have identified potentially useful combinations. Standardization of assay methods and adoption of common interpretive criteria are essential to avoid discrepancies between different in vitro studies. Larger clinical trials are needed to assess whether combination therapy improves survival and treatment outcome in the most seriously debilitated patients afflicted with life-threatening fungal infections.

Cryptococcus neoformans isolates from transplant recipients are not selected for resistance to calcineurin inhibitors by current immunosuppressive regimens

The immunosuppressants tacrolimus (FK506) and cyclosporine A inhibit calcineurin and have potent antifungal activity. In this study, 24% of Cryptococcus neoformans isolates from solid-organ transplant patients exhibited altered sensitivity to these drugs, which may have an impact on the infectious course but does not appear to be the consequence of immunosuppressive therapy.

Antifungal combination therapy: clinical potential

Combination antifungal therapy has been an area of research and clinical interest since systemic antifungals became available decades ago. In vitro and clinical data were generated for some of the more common invasive fungal infections, especially candidiasis, but until very recently few clinical studies were performed. The first invasive fungal infection to be examined in clinical trials with adequate statistical power was cryptococcal meningitis and several of these trials stand out as classical studies in the clinical evaluation of combination antifungal therapy. More recently, since the availability of the newer antifungal agents, including the echinocandins and extended-spectrum triazoles, there has been a growing interest in examining combination antifungal therapy for invasive fungal disease, especially invasive aspergillosis. This is by no means a comprehensive review of all existing experimental data. Instead, the focus is on the clinical data that have been generated to date and on providing insights into potential future clinical directions. For instance, recent clinical data for cryptococcosis confirm that amphotericin B plus flucytosine is the most active combination for patients with cryptococcal meningitis. A recently completed clinical trial in candidaemia suggests a trend towards improved outcomes among patients receiving amphotericin B plus fluconazole versus fluconazole alone. In aspergillosis, several experimental models suggest benefit of a variety of antifungal combinations, but have not been confirmed in prospective clinical trials. Ultimately, the goal is to provide the reader with a comprehensive but useful review to this complicated and often confusing therapeutic dilemma.

[Treatment and prophylaxis of opportunistic infections in the course of HIV disease: a state of the art in 2004. Part 2: Viral, fungal and bacterial infections]

Remarkable progress has been made in antiretroviral therapeutics, as well as in the prophylaxis and treatment of opportunistic infections, since the beginning of the AIDS epidemic. The patient's life expectancy and quality of life have consequently improved, thanks to better management of opportunistic diseases. The introduction of protease inhibitors-containing regimen (i.e. highly active antiretroviral therapy or HAART), since 1996, has drastically reduced the incidence of opportunistic infections by restoring immunity. The large panel of antiretroviral drugs responsible for frequent sustained viral and immune responses has thus allowed a new definition of guidelines for the prophylaxis and treatment of opportunistic infections. A better use of prophylactic drugs should help to reduce the risk of drug-related toxicity and pharmaceutical interactions. It should also decrease the cost of HIV management and eventually increase compliance to treatment and quality of life.

The effects of renal impairment on the pharmacokinetics and safety of fosfluconazole and fluconazole following a single intravenous bolus injection of fosfluconazole

AIMS

Fosfluconazole is a phosphate prodrug of fluconazole (FLCZ). This study was conducted to investigate the effect of renal impairment on the pharmacokinetics of fosfluconazole and FLCZ, and to assess the safety and toleration of fosfluconazole following a single intravenous bolus injection of fosfluconazole in subjects with normal and impaired renal function.

METHODS

In an open, parallel-group, two-centre study, subjects with normal and impaired renal function received a single 1000-mg bolus intravenous injection of fosfluconazole. Subjects were categorized as Normal (> 80 ml min(-1)), Mild (51-80 ml min(-1)), Moderate (30-50 ml min(-1)) or Severe (< 30 ml min(-1)) impairment group according to their Cockcroft and Gault creatinine clearance (CLcr) values. Concentrations of fosfluconazole and FLCZ were determined in plasma and urine samples taken up to 240 h and 48 h postdose, respectively.

RESULTS

Fosfluconazole plasma concentrations were very similar across the four groups, and there was no apparent relationship between any of the fosfluconazole pharmacokinetic parameters with increasing renal impairment. The conversion of fosfluconazole to FLCZ was unaffected by the degree of renal impairment. Only small amounts of fosfluconazole were excreted in the urine suggesting almost complete conversion to FLCZ. FLCZ concentrations were still detected in plasma after 240 h postdose and remained higher at the later sampling times in subjects in the Moderate and Severe groups. The area under the plasma concentration vs. time curve between time zero and infinity (AUC), the terminal elimination phase half-life (t(1/2)) and the mean residence time (MRT) of FLCZ all increased with the degree of renal impairment. The ratios (95% confidence interval) for AUC (Renal impairment group/Normal group) were 112.8% (89.5, 142.1), 240.6% (128.2, 451.4) and 355.1% (259.3, 486.3) for the Mild, Moderate and Severe impairment groups, respectively. There was a linear relationship between CLcr with AUC, t(1/2), MRT and the total plasma clearance of FLCZ (CL/F). Both the amount excreted over 48 h in the urine and the renal clearance of FLCZ decreased with an increase in renal impairment. The adverse events reported were mild to moderate in intensity, and there was no observed relationship with impairment group. There were no severe or serious adverse events, and in general fosfluconazole was well tolerated.

CONCLUSIONS

The pharmacokinetics of fosfluconazole, including its efficient conversion into FLCZ, were unaffected by renal impairment. For FLCZ, there was a significant linear relationship between CLcr and AUC, t(1/2), MRT and CL/F, with AUC, t(1/2) and MRT increasing and CL/F decreasing as renal impairment increased. The dose adjustment used for FLCZ (half normal dose for patients with CLcr at <or= 50 ml min(-1)) can be applied to fosfluconazole as well. There were no safety concerns for any subject in this study, and fosfluconazole and FLCZ were well tolerated by all the treatment groups.

Guidelines for the diagnosis and management of neurological complications of HIV infection

The spectrum of neurological complications of HIV-infection has remained unchanged through the years, but its epidemiology changed remarkably as a result of the introduction of highly active antiretroviral therapy (HAART). Guidelines for the diagnosis and treatment of cerebral toxoplasmosis, cryptococcal meningitis, progressive multifocal leukoencephalopathy, CMV encephalitis, CMV polyradiculomyelitis, tuberculous meningitis, primary CNS lymphoma, HIV dementia, HIV myelopathy and HIV polyneuropathy are given with a grading of evidence and recommendations.

Cryptococcus neoformans Infection in Patients With Cirrhosis, Including Liver Transplant Candidates

We reviewed the cases of patients with cirrhosis, including liver transplant candidates, at our institution in the last 3 years (n = 5) and those individually described in the literature (n = 28), to assess unique characteristics and outcome of cryptococcosis in these patients. Sixty-four percent (21/33) of the patients had no other recognized immunosuppression. Peritonitis (in 45%, 15/33 of the patients) with modest pleocytosis in the ascitic fluid, was the most common presenting feature. Median time to detection of Cryptococcus in the ascitic fluid cultures was 6 days. Overall mortality rate was 81% (26/32); death was deemed attributable to cryptococcosis in 24/26 patients who died. Evaluation of culture-negative neutrocytic ascites in febrile cirrhotic patients warrants consideration of cryptococcal peritonitis.

In vitro and in vivo efficacies of the new triazole albaconazole against Cryptococcus neoformans

The activity of albaconazole (UR-9825; J. Uriach & Cía. S.A., Barcelona, Spain) was compared to that of fluconazole against 12 isolates of Cryptococcus neoformans in vitro and against 1 isolate in vivo in a rabbit model of cryptococcal meningitis. Albaconazole was 100-fold more potent in vitro than fluconazole on a per-weight basis and was fungicidal at potentially relevant concentrations for two isolates. MICs ranged from </=0.0012 to 1.25 micro g/ml, with the MICs for most isolates being between 0.039 and 0.156 micro g/ml. Isolates were from human immunodeficiency virus (HIV)-infected and non-HIV-infected patients and were of serotypes A, B, and C; and the fluconazole MICs for some of the isolates were elevated. Infected rabbits were treated with either fluconazole or albaconazole at dosages ranging from 5 to 80 mg/kg of body weight/day. The peak concentrations of albaconazole in serum and cerebrospinal fluid (CSF) averaged 4.14 and 0.62 micro g/ml, respectively, in animals receiving 80 mg/kg/day. Comparison of the concentrations in serum and CSF suggested a level of CSF penetration of approximately 15%. Despite limited penetration into the subarachnoid space, at all three doses tested albaconazole was as effective as fluconazole for the treatment of cryptococcal meningitis in rabbits.

Epidemiology of HIV-associated cryptococcosis in France (1985-2001): comparison of the pre- and post-HAART eras

OBJECTIVE

To analyse the epidemiological evolution of cryptococcosis in France after the introduction of highly active antiretroviral therapy (HAART).

DESIGN

Retrospective study of cryptococcosis cases recorded at the National Reference Center for Mycoses in France since 1985.

METHODS

Using the national surveillance data, we reviewed 1644 cases of HIV-associated cryptococcosis diagnosed in France (population, 59 million) between 1985 and 2001 and compared them to 335 cases recorded in HIV-negative patients.

RESULTS

The total number of cryptococcosis cases evolved in parallel to that recorded for HIV-infected patients. Changes occurring after HAART introduction were analysed. A negative binomial regression model established a 46% decrease of the incidence of cryptococcosis during the post-HAART era (1997-2001, n = 292) compared to the pre-HAART era (1985-1996, n = 1352). According to multivariate analysis, African origin, older age, heterosexual HIV contamination, no previous AIDS-defining illness, and no previous HIV infection diagnosis were variables independently associated with an increased risk of cryptococcosis during the post-HAART era. During the same period, the characteristics of the HIV-negative population did not change.

CONCLUSIONS

Our analysis of the national surveillance identified demographic factors associated with an increased risk of cryptococcosis in the post-HAART era suggesting that failure to consult and considering oneself not at risk were determinant in the current epidemiology of HIV-related cryptococcosis in France.

Aggregation of Cryptococcus neoformans by surfactant protein D is inhibited by its capsular component glucuronoxylomannan

Cryptococcus neoformans is an opportunistic pathogen invading the immunocompromised host. Infection starts with the inhalation of acapsular or sparsely encapsulated cells, after which capsule synthesis is initiated. The capsule is the main virulence factor of this yeast-like fungus. Pulmonary surfactant protein D (SP-D) is an important component of the local innate defense system. In the present study, interactions of SP-D with intact C. neoformans cells and their isolated capsular components were investigated. Although encapsulated cryptococci were bound, SP-D showed the highest affinity for acapsular C. neoformans. Only acapsular cryptococci were aggregated by SP-D. Furthermore, the cryptococcal capsular components glucuronoxylomannan (GXM) and mannoprotein 1 (MP1) were bound with relatively high affinity, in contrast to GalXM and MP2. Binding as well as aggregation of acapsular C. neoformans by SP-D could be inhibited by GXM in concentrations that are likely to be present in the lung after infection, suggesting that not only the capsule hampers SP-D function within the innate defense system of the lung but also the secreted capsular component GXM.

Mucosal and Systemic Fungal Infections in Patients with AIDS

In countries where highly active antiretroviral therapy (HAART) is widely available, a decrease in the incidence of fungal infections has been observed in the last 5 years compared with countries that cannot afford this treatment. Even refractory fungal infections may be controlled when HAART is given to patients, and end-stage AIDS infections, such as aspergillosis, are now only infrequently seen. In contrast, fungal infections in certain regions, such as penicilliosis in Southeast Asia or cryptococcosis in Sub-Saharan Africa, are a growing problem. Antifungal therapy for documented infections has not changed very much during recent years; however, new drugs such as caspofungin and voriconazole may be more effective in the treatment of opportunistic fungal infections, in particular, those involving resistant organisms. Secondary antifungal prophylaxis for many opportunistic pathogens can now be temporarily or even permanently discontinued in many HIV-positive patients who have a marked improvement in immune function parameters, such as CD4(+) cell counts, after initiation of HAART. The link between effective virustatic control of HIV infection and a decreasing incidence of fungal infections has been recognised; and so, despite the availability of very effective new antifungal drugs, the cornerstone of treatment and prevention of opportunistic fungal infections in patients with HIV infection is effective antiretroviral therapy including protease inhibitors.

Cryptococcal meningitis

Cryptococcal meningitis is a common opportunistic infection in AIDS patients, particularly in Southeast Asia and Africa. Cases also occur in patients with other forms of immunosupression and in apparently immunocompetent individuals. Mortality from HIV-associated cryptococcal meningitis remains high (10-30%), even in developed countries, because of the inadequacy of current antifungal drugs and the complication of raised intracranial pressure. In cohorts of HIV-infected patients from sub-Saharan Africa, cryptococcosis has accounted for 13-44% of all deaths. Optimal current therapy is with amphotericin B 0.7-1 mg/kg/day plus flucytosine 100 mg/kg/day for 2 weeks, followed by fluconazole 400 mg/day for 8 weeks and 200 mg/day thereafter. Saline loading reduces amphotericin B nephrotoxicity. If there is no contraindication on CT head scan, repeat lumbar puncture with drainage of cerebrospinal fluid (CSF) is recommended for patients with very raised CSF opening pressure. Expansion of antiretroviral programmes raises the prospect of transforming the long-term prognosis of these patients, provided that they survive the acute phase of the illness. Studies are needed to define more fungicidal drug regimens and to improve the treatment of raised intracranial pressure.

Oral versus intravenous therapy in the treatment of systemic mycosis

The great majority of systemic fungal infections require long-term therapy that often extends 6-12 months, particularly in immunosuppressed patients. It can be difficult to comply with this requirement when the drug to be used is only available for intravenous administration, because problems related to maintaining a permeable venous pathway for long periods arise. The availability of an intravenously (IV) and orally (PO) administered drug can solve this problem by making sequential therapy possible. Voriconazole is a new antifungal agent that, apart from satisfying this requirement because it has a high oral bioavailability, presents a broad spectrum of antifungal activity that makes its use possible, a priori, in the initial and/or sequential IV/PO treatment of any systemic mycotic infection. Based on current costs there is potential for savings compared with liposomal amphotericin B.

[Guidelines for the treatment of invasive fungal infection. Invasive fungal infection by Candida spp. Invasive Fungal Infection Study Group (MICOMED) and Infection in Transplantation Study Group (GESITRA) of the Spanish Society for Infectious Diseases and Clinical Microbiology (SEIMC)]

These guidelines resume different issues related to the clinical management of invasive candidosis in the immunossuppressed patients. They are based on the recommendations of the different Drug's Agencies.

Amphotericin B: time for a new "gold standard"

When introduced in 1959, amphotericin B deoxycholate (AmBD) was clearly a life-saving drug. Randomized studies demonstrating its efficacy were not thought to be necessary, and it was granted indications for many invasive fungal infections. Despite its formidable toxicities, AmBD is thus often used as the primary comparator in studies of invasive fungal infections. Safer lipid-based versions of amphotericin B (AmB) have been introduced, but difficulties with studying these agents generally led to licensure for salvage therapy, not primary therapy. However, the cumulative clinical experience to date with the lipid-based preparations is now adequate to demonstrate that these agents are no less active than AmBD, and, for some infections, it can now be stated that specific lipid-based preparations of AmB are superior to AmBD. Given their superior safety profiles, these preparations can now be considered suitable replacements for AmBD for primary therapy for many invasive fungal infections in clinical practice and research.

British Society for Medical Mycology proposed standards of care for patients with invasive fungal infections

Outcomes for invasive fungal infections have greatly improved in the past decade, and several new antifungal drugs have been or will be licensed in the next few years. Early accurate diagnosis and appropriate treatment have major impact on survival. In a 1995 survey of laboratory practice in the UK for mycology, major disparities were seen, with many laboratories not undertaking even simple diagnostic procedures. Delays in processing and inadequate procedures for handling samples, incomplete or delayed reporting of results, or a combination of these, compromise the care of patients. In randomised trials of antifungal chemotherapy, optimum treatments and good alternatives for others have been defined for some infections. High-quality care requires a multidisciplinary approach to diagnosis and management. In this review, we propose microbiology, histopathology, radiology, and clinical auditing standards, with the evidence base for each reviewed. The standards are absolutes, and, therefore, provide a straightforward basis for improving services to patients if they are all implemented.

Immunomodulation of invasive fungal infections

Genetic and acquired (disease- or therapy- related) host immune factors increase the risk for IFIs. In addition to antifungal drug therapy, modulation of host defenses by the use of HGFs and IFN-gamma has been supported by extensive in vitro and in vivo preclinical data. Clinical studies on the prevention or the adjunctive therapy of IFIs in combination with antifungal agents are limited, however, and do not allow specific recommendations for their cost-effective use in most of the immunodeficient settings. There is an urgent need to push forward with well-structured, randomized clinical trials to determine optimal dose, duration, and timing for different combinations of immunotherapy and antifungal agents in high-risk patients.

Antifúngicos de uso sistémico

Invasive fungal infection is the infectious complication with highest associated mortality. Until the 90's amphotericin B was the only drug available to treat these infections. Its spectrum of antifungal activity is excellent, but its use is associated with toxicity in many cases. The development of amphotericin B lipid formulations has resulted in a significant decrease in most of the side effects associated with this drug. Triazoles are safe and effective for treating most invasive fungal infections. Fluconazole is an excellent drug for the prevention and treatment of Candida and Cryptococcus infections, itraconazole has good activity against Candida and Aspergillus, and voriconazole has shown to be better than amphotericin B for invasive aspergillosis. Caspofungin belongs to a new group of antifungal agents, the echinocandins, which are very safe and present excellent activity against Candida and Aspergillus.

Cryptococcosis

Cryptococcus neoformans has risen to a worldwide highly recognizable major opportunistic pathogen with deadly consequences. It has become a model fungus to study a variety of paradigms in the host-fungus relationships. Genomic studies are advancing knowledge on its evolution and dissecting its virulence composite. Studies designed to understand host immunology to this fungus are leading to development of active and passive prevention and therapeutic strategies. This article collates and analyzes both new and old knowledge about the pathogen to help frame the meaning of human cryptococcosis as it starts to evolve in the new millennium.

Looking beyond highly active antiretroviral therapy: drug-related hepatotoxicity in patients with human immunodeficiency virus infection

Management of human immunodeficiency virus (HIV) has become increasingly complex since the introduction of highly active antiretroviral therapy (HAART). Patients with HIV have become exposed to an increasing array of drugs to treat HIV, prevent opportunistic infections and immune dysfunction, and manage comorbid illnesses and therapeutic complications. Hepatic complications have become common and may lead to discontinuation of treatment and significant morbidity. Up to 90% of patients with acquired immunodeficiency syndrome (AIDS) receive at least one drug that can cause hepatotoxicity. Clinicians treating patients with HIV frequently face difficulty distinguishing abnormal liver transaminase levels and toxicities in patients receiving several drugs. Some potential causes of hepatic dysfunction are viral infections, alcohol and substance abuse, and hepatotoxic drugs such as HAART. Recent reports have focused on the hepatotoxicity of HAART and the role of hepatitis viruses to the exclusion of many other agents prescribed for patients with HIV. Many of the common antibiotics, antifungals, antivirals, and ancillary agents prescribed for patients with HIV are independently associated with hepatotoxicity. Clinicians should be aware of the potential non-antiretroviral hepatotoxic agents that are frequently administered in HIV management.

HIV and the central nervous system

Neurological complications of HIV infection are common with clinically recognized disorders ultimately affecting between 40% and 75% of patients. The spectrum of neurological disease is broad. This article highlights the common disorders of the central nervous system associated with HIV/AIDS.

Management of Increased Intracranial Pressure in Cryptococcal Meningitis

Therapy of cryptococcal meningitis has been focused primarily on optimizing the antifungal regimen to improve the previously high treatment failure rates. Until recently, relatively little attention has been paid to the impact of increased intracranial pressure, which is a frequent problem that complicates management of patients with cryptococcal meningitis. Patients with elevated baseline opening pressures have higher titers of cerebrospinal fluid cryptococcal capsular polysaccharide antigen, more frequent headaches, meningismus, papilledema, hearing loss, and pathologic reflexes, as well as increased morbidity and mortality compared with those patients with normal opening pressures. Optimal therapy has not yet been firmly established, but the diagnostic evaluation and available treatment options are reviewed here, including frequent high volume lumbar punctures, lumbar drains, ventriculoperitoneal shunting, and corticosteroids.

AIDS related opportunistic infections, going but not gone

It is now more than two decades since the AIDS epidemic began with a cluster of Pneumocystis carinii pneumonia (PCP) in a community of homosexual men. Since then, many other infections have been characterized as opportunistic infections secondary to HIV infection. These include, but are not limited to, infections with Toxoplasma gondii, Cytomegalovirus (CMV), Mycobacterium avium complex (MAC), and Cryptococcus neoformans. Over the last two decades, there have been dramatic improvements in diagnosis, prevention and treatment of all these infections. As a result, in North America and Western Europe the rates of opportunistic infections secondary to AIDS have decreased substantially. We will review these common opportunistic infections below.

Central nervous system infection during immunosuppression

Suppression of the immune system by human immunodeficiency virus (HIV) infection or immunosuppressive therapy following transplantation increases susceptibility to CNS infection. Examination of the level and type of immunosuppression, in addition to the clinical and radiologic findings at the time of diagnosis can aid the clinician in determining the most likely etiology of infection. This article discusses how suppression of the host immune status modifies the presentation and diagnosis of selected CNS infections and the recommended treatment for these infections.

Pulmonary cryptococcosis: a case report and review of the Asian-Pacific experience

Pulmonary cryptococcosis is a very rare form of pneumonia, which is seldom seen among immunocompetent patients. We report the case of a 36-year-old man who presented with indolent pneumonia that was subsequently diagnosed to be pulmonary cryptococcosis without other systemic involvement. Contrary to formal belief, there was evidence of residual lung fibrosis 12 months after initial presentation. The features of pulmonary cryptococcosis reported in the Asian Pacific region are also reviewed.

Case report. Recurrence of increased intracranial pressure with antiretroviral therapy in an AIDS patient with cryptococcal meningitis

We present the case of an AIDS patient with cryptococcal meningitis who, after an excellent clinical and mycological response to antifungal therapy, developed an exacerbation of signs and symptoms, including elevated intracranial pressure and an increase in cerebrospinal fluid cryptococcal antigen and white blood cells, following the initiation of highly active antiretroviral therapy (HAART). Cultures yielded no growth and the patient responded to repeated lumbar punctures without changing or intensifying antifungal therapy. To our knowledge, this is the first report of symptomatic elevated intracranial pressure occurring during HAART-related immune recovery in a patient with cryptococcal meningitis. Exacerbation of symptoms does not necessarily reflect mycological failure that requires a change in antifungal therapy, but may relate to acutely increased intracranial pressure that will respond to simple measures, such as repeated lumbar punctures.

Synthesis and characterisation of a new amphotericin B-methoxypoly(ethylene glycol) conjugate

The reaction of methoxypoly(ethylene glycol)-4-nitrophenyl carbonate with amphotericin B has been used to prepare a new conjugate of amphotericin B (mPEG-AmB). A preliminary screening of in vitro antifungal activity has suggested that mPEG-AmB possesses a similar effect and a similar spectrum of activity as the conventional amphotericin B formulated with sodium desoxycholate.

A prospective study of AIDS-associated cryptococcal meningitis in Thailand treated with high-dose amphotericin B

OBJECTIVE

To assess kinetic of cryptococci in the cerebrospinal fluid (CSF) and outcome of AIDS-associated cyptococcal meningitis after high-dose amphotericin B.

PATIENTS AND METHODS

A prospective study involving Thai adults (n=106) with cryptococcal meningitis associated with AIDS was conducted to determine the kinetic of cryptococci in CSF and prognostic factors affecting survival after high-dose amphotericin B (0.7 mg/kg/day) followed by oral azole treatment. Cerebrospinal fluids were collected for cryptococcal count and culture at weekly intervals for at least 2 weeks or until CSF cultures were negative for cryptococci. All patients were followed monthly for 1 year or until death in order to detect relapse or occurrence of any other opportunistic infection.

RESULTS

A total of 106 AIDS patients with cryptococcal meningitis were enrolled. The geometric mean (range) total and viable cryptococcal counts in CSF on admission were 430,000 (1000 to 3.4 x 10(7)) and 31,000 (10 to 1.4 x 10(7)) per ml, respectively. Both total and viable cryptococcal counts declined monoexponentially with an elimination half life of 4 days. The cumulative CSF yeast clearance rates were 38% and 56% at 2 and 4 weeks, respectively. Early death was associated significantly with previous history of weight loss [relative risk (RR)=2.2; 95% CI, 1.2-3.9], Glasgow Coma Score <13 (RR=2.33; 95% CI, 1.55-3.50), and hypoalbuminaemia (P<0.001). Later mortality was associated delayed CSF yeast clearance (RR=3.6; 95% CI, 1.9--6.4) and relapse (RR=3.9; 95% CI, 1.4-10.8).

CONCLUSION

High-dose amphotericin B was not as effective as previously thought. Cumulative mortality at 2 weeks, 4 weeks and 1 year were 16%, 24% and 76%, respectively.

Cryptococcal Meningitis

Cryptococcal meningitis, often seen in immunocompromised hosts, is also a disease of the immune-competent individual. The diagnosis of cryptococcal meningitis requires a lumbar puncture with measurement of the opening pressure, standard laboratory assessment including cell count, protein and glucose, fungal culture, and cryptococcal polysaccharide antigen. Serum cryptococcal antigen is of great diagnostic value in individuals infected with HIV. Hospital admission for initial therapy with amphotericin B desoxycholate is required. Adjuvant oral therapy with flucytosine for the first 2 weeks of therapy is strongly recommended. If flucytosine is not well tolerated, it may be discontinued with close monitoring and follow-up of cerebrospinal fluid (CSF) response to therapy. Good hydration and appropriate premedication concomitant to the use of amphotericin B are useful interventions preventing side effects. Occasionally, amphotericin B needs to be discontinued due to intolerance or side effects. After CSF sterilization is completed, therapy can be switched to oral fluconazole. Fluconazole is well absorbed orally. There is rarely a need to give intravenous fluconazole.

Cryptococcosis in human immunodeficiency virus-negative patients in the era of effective azole therapy

We conducted a case study of human immunodeficiency virus (HIV)-negative patients with cryptococcosis at 15 United States medical centers from 1990 through 1996 to understand the demographics, therapeutic approach, and factors associated with poor prognosis in this population. Of 306 patients with cryptococcosis, there were 109 with pulmonary involvement, 157 with central nervous system (CNS) involvement, and 40 with involvement at other sites. Seventy-nine percent had a significant underlying condition. Patients with pulmonary disease were usually treated initially with fluconazole (63%); patients with CNS disease generally received amphotericin B (92%). Fluconazole was administered to approximately two-thirds of patients with CNS disease for consolidation therapy. Therapy was successful for 74% of patients. Significant predictors of mortality in multivariate analysis included age > or =60 years, hematologic malignancy, and organ failure. Overall mortality was 30%, and mortality attributable to cryptococcosis was 12%. Cryptococcosis continues to be an important infection in HIV-negative patients and is associated with substantial overall and cause-specific mortality.