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

Cryptococcal meningitis after liver transplantation

We present our experience with 10 liver transplant recipients in whom cryptococcal meningitis developed after liver transplantation. Disease developed a median period of 3.5 months (range, 2-36 months) after transplantation and patients were diagnosed a median period of 9 days (range, 2-90 days) after initial symptoms. Headache, fever, and mental status changes were the most frequent clinical presentations, while meningismus was found in only 30% of patients. Cerebrospinal fluid analysis was diagnostic in all cases. All patients were treated with amphotericin B and flucytosine. Immunosuppression was either decreased or discontinued during therapy. Five patients died, four as a direct result of cryptococcal infection and one as a result of chronic rejection. Three patients had long-term survival without any sequelae. One long-term survivor suffered blindness consequent to the disease. We conclude that cryptococcal meningitis is a rare complication in liver transplant recipients (0.25%), and has a high mortality rate (50%). Early recognition, combination antifungal therapy, and decrease or discontinuation of immunosuppression are important for cure. No relapse has been seen in surviving patients.

Yeast infections

Yeasts are unicellular fungi that reproduce by the process of budding in which daughter cells are produced from parents by outpouching of the cell membrane and wall, migration of cytoplasm into the new structure thus formed, and then separation from the parent cell. Yeasts that are pathogenic in humans range in size from 2 to 12 microns in diameter; most, therefore, can be engulfed by phagocytic cells. These pathogens include many of the best known of pathogenic fungi, such as the Candida species, Cryptococcus neoformans, and the lipophilic yeasts of the genus Malassezia.

Fungal infections in immunocompromised individuals

This article examines the expression of fungal infections seen with different immunodeficiency states and discusses how the sequential appearance of different diseases serves as a harbinger of clinical disease progression. The effect of an immunocompromised state on the medical history, physical findings, and natural history of fungal infections are discussed. The appearance and increased frequency of rare fungal infections, made possible by immunosuppression, are highlighted.

Comparison of D0870 and fluconazole in the treatment of murine cryptococcal meningitis

Cryptococcal meningitis is a common infection in patients with AIDS. Using a murine cryptococcosis model, we compared treatment with a new triazole, D0870, and fluconazole. Groups of ICR (Institute for Cancer Research) mice were infected intracerebrally with eight different isolates of Cryptococcus neoformans variety neoformans with different in vitro susceptibilities to fluconazole. For survival studies mice were challenged with two to four times LD(50) or six to nine times LD(50). Treatment was given for 10 days. Mice were observed through to day 30. To assess the effect of treatment on fungal tissue burden, mice received a three to five times LD(50) inoculum and treatment for 10 days. They were sacrificed on day 12 and serial dilutions of brain homogenates were cultured. Fluconazole prolonged survival primarily in isolates which were susceptible in vitro. D0870 prolonged survival in all isolates except one, which was also resistant in vitro to D0870 and fluconazole. Both drugs reduced colony counts of all isolates. D0870 warrants further development for use in cryptococcosis, and appears effective for isolates relatively resistant to fluconazole. There is a relative correlation of in vivo and in vitro susceptibility to D0870 as well as fluconazole.

Cryptococcosis in the era of AIDS--100 years after the discovery of Cryptococcus neoformans

Although Cryptococcus neoformans and cryptococcosis have existed for several millennia, a century has passed since the discovery of this encapsulated yeast and its devastating disease. With the advent of the AIDS pandemic, cryptococcal meningitis has emerged as a leading cause of infectious morbidity and mortality and a frequently life-threatening opportunistic mycosis among patients with AIDS. Both basic and clinical research have accelerated in the 1990s, and this review attempts to highlight some of these advances. The discussion covers recent findings, current concepts, controversies, and unresolved issues related to the ecology and genetics of C. neoformans; the surface structure of the yeast; and the mechanisms of host defense. Regarding cell-mediated immunity, CD4+ T cells are crucial for successful resistance, but CD8+ T cells may also participate significantly in the cytokine-mediated activation of anticryptococcal effector cells. In addition to cell-mediated immunity, monoclonal antibodies to the major capsular polysaccharide, the glucuronoxylomannan, offer some protection in murine models of cryptococcosis. Clinical concepts are presented that relate to the distinctive features of cryptococcosis in patients with AIDS and the diagnosis, treatment, and prevention of cryptococcosis in AIDS patients.

Interferon gamma increases survival in murine experimental cryptococcosis

Systemic disease by Cryptococcus neoformans (C. neoformans) is a common opportunistic infection in immunodeficient patients. Cellular immunity seems to be the most important determinant of resistance. The aim of this study was to assess the effect of recombinant rat interferon gamma (IFN-gamma) in murine cryptococcosis (Balb/c mice infected by IP route with the Rivas strain of C. neoformans), evaluating survival time, macroscopic and microscopic examination of the organs, and massive seeding of brain homogenate. IFN-gamma treatment, at a daily dose of 10,000 IU, did not modify significantly these variables when mice were challenged with a high inoculum (10(7) yeasts) and treatment was delayed to 5 days after infection (median survival 21 days in control mice vs. 23 days in IFN-treated). Another set of experiments suggested that IFN-gamma treatment, at a dose of 10,000 IU/day, begun at the moment of infection could be useful (it prolonged survival from 20 to 28 days, although the difference did not achieve statistical signification). When used simultaneously with infection by 3.5 x 10(5) yeasts, IFN-gamma at 10,000 IU/day for 15 days significantly prolonged survival of mice (p = 0.004). These results suggest that, depending on the experimental conditions, IFN-gamma can improve survival of mice infected with a lethal dose of C. neoformans.

Sterol compositions and susceptibilities to amphotericin B of environmental Cryptococcus neoformans isolates are changed by murine passage

Previous studies have shown that sequential isolates from patients with persistent Cryptococcus neoformans meningoencephalitis can vary in sterol composition and susceptibility to antifungal drugs. To investigate the potential of host factors as mediators of this phenomenon, we compared fungal susceptibilities of environmental and clinical isolates from a limited geographic area. Clinical isolates were less susceptible to amphotericin B than environmental isolates. Five environmental isolates were passaged through BALB/c murine hosts; the passaged isolates had changes in sterol composition and reduced amphotericin B susceptibilities relative to those of the parent isolates. In contrast, murine passage of these isolates did not alter their susceptibilities to fluconazole. The results confirm that changes in sterol composition and antifungal susceptibility can occur in vivo as a result of host factors and suggest that human infection can result in selection of variants with reduced susceptibilities to amphotericin B.

In vitro evaluation of combination of fluconazole and flucytosine against Cryptococcus neoformans var. neoformans

Amphotericin B and fluconazole are current acceptable therapies for cryptococcal meningitis; however, their effect remains suboptimal. The combination of fluconazole and flucytosine has yielded encouraging clinical results in human immunodeficiency virus patients with cryptococcal meningitis. To investigate the biological basis of this finding, we performed in vitro combination testing of fluconazole and flucytosine against 50 clinical strains of Cryptococcus neoformans var. neoformans. Synergy (fractional inhibitory concentration index of < 1.0) was observed in 62% of cases, while antagonism (fractional inhibitory concentration index of > 2.0) was not observed. For cases in which synergy was not achieved (autonomous or additive effects), the beneficial effect of the combination was still seen (i.e., there was still a decrease, although not as dramatic, in the MIC of one or both drugs when used in combination). The in vitro inhibitory action of flucytosine was greatly enhanced by the addition of fluconazole; the flucytosine MICs for Cryptococcus isolates were markedly decreased to concentrations which were severalfold lower than the achievable cerebrospinal fluid flucytosine concentration. On the other hand, the addition of flucytosine did not greatly enhance the in vitro activity of fluconazole if the initial fluconazole MIC for the isolate was > or = 8 micrograms/ml. Controlled clinical studies are warranted to further elucidate the potential utility of fluconazole-flucytosine combination therapy.

Disseminated cryptococcal infection despite treatment for cryptococcal meningitis

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Fluconazole penetration in cerebral parenchyma in humans at steady state

We studied fluconazole penetration in the brain in five patients who had a deep cerebral tumor whose removal required the excision of healthy brain tissue. Plasma and brain samples were simultaneously obtained after oral ingestion of 400 mg of fluconazole daily for 4 days (90% of steady state). Fluconazole penetration in healthy cerebral parenchyma was determined. Plasma and brain samples were assayed by high-pressure liquid chromatography. Concentrations in plasma and brain tissue were 13.5 +/- 5.5 micrograms/ml and 17.6 +/- 6.6 micrograms/g, respectively. The average ratio of concentrations in the brain and plasma (four patients) was 1.33 (range, 0.70 to 2.39). Despite the lack of data concerning the penetration of fluconazole in brain abscesses, these results should permit the use of a daily dose of 400 mg of fluconazole in prospective clinical studies that evaluate the effectiveness of this drug in the treatment of brain abscesses due to susceptible species of fungi.

Use of a colorimetric system for yeast susceptibility testing

We examined the reliability and accuracy of a colorimetric assay using Alamar Blue reagent in the performance of susceptibility tests for Candida albicans. We compared the broth macrodilution method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) with a macrodilution method modified with the Alamar reagent and a microdilution method modified with the Alamar reagent. The MICs of fluconazole and itraconazole for 97 isolates of C. albicans and 3 control isolates were tested. For fluconazole, the Alamar-modified broth macrodilution method yielded 94% (91 of 97) concordance within 2 dilutions compared with the NCCLS method, while the microdilution method yielded 95% (92 of 97) concordance. With Alamar-modified methods for itraconazole, broth macrodilution yielded 97% (94 of 97) concordance within 2 dilutions. MICs obtained by the microdilution method, although tightly nested, were shifted to a higher value when compared with those obtained by the NCCLS method; there was only 77% (75 of 97) concordance within 2 dilutions but 97% concordance (94 of 97) within 3 dilutions. Tests by all methods with quality control strains showed excellent reproducibilities. For fluconazole, the methods modified with the Alamar reagent yielded clear endpoints and excellent correlation for the broth macrodilution and microdilution methods. For itraconazole, the methods modified with the Alamar reagent yielded clear endpoints and were reproducible, but higher MICs were obtained by the microdilution methods compared with those obtained by the NCCLS methods.

Treatment of exogenous Candida endophthalmitis in rabbits with oral fluconazole

We investigated the efficacy of oral fluconazole, alone or in combination with oral flucytosine (5FC), in treating Candida endophthalmitis using a rabbit model. Albino rabbits were infected with an intravitreal inoculation of 1,000 CFU of susceptible Candida albicans and randomized 5 days later to receive treatment with oral fluconazole alone (80 mg/kg of body weight per day), a combination of fluconazole and 5FC (100 mg/kg/12 h), or no treatment. The treatment effect was assessed at 2 and 4 weeks after therapy by funduscopy, quantitative vitreous culture, and histopathology. Intravitreal levels of fluconazole, 2 to 24 h after the first dose, were measured to be > 10 times the MIC of the drug for C. albicans. Among rabbits treated with fluconazole for 2 weeks, 67% had a > 90% reduction in fungal load (P < 0.05) and 33% were sterile. After 4 weeks, all had a > 99% reduction in fungal load (P < 0.05) and 75% were sterile (P = 0.01). This treatment effect was unchanged 4 weeks after discontinuation of fluconazole. Among rabbits treated with fluconazole and 5FC for 2 weeks, 67% died during therapy. Among the surviving rabbits, 75% had a > 90% reduction in fungal load (P < 0.05) and 25% were sterile. We conclude that oral fluconazole may be useful for treatment of Candida endophthalmitis. Addition of 5FC was associated with high toxicity and minimal additional antifungal effect in our rabbit model.

Primary prevention of cryptococcal meningitis by fluconazole in HIV-infected patients

To evaluate whether oral fluconazole reduces the risk of a first episode of cryptococcal meningitis in HIV-infected patients, we conducted a case-control study of patients cared for in a university teaching hospital and two urban HIV-outpatient clinics. Cases consisted of HIV-infected patients with CD4 cell counts less than 250/microL who developed a first episode of cryptococcal meningitis between July 1, 1990, and June 30, 1993. For each case (n = 18), 4 control subjects were chosen from HIV-infected patients (CD4 count < 250/microL) whose cerebrospinal fluid was negative for cryptococcal antigen and culture, and who were matched by age, sex, and time of lumbar puncture. There were no significant differences between cases and controls in age, sex, insurance status, mean CD4 count, history of oral candidosis, presence of a previous AIDS-defining illness, the number of visits to the HIV-outpatient clinic, or use of antiretroviral therapy. In the 6 months before lumbar puncture, 2 of 18 cases (11%) and 26 of 72 controls (36%) were exposed to fluconazole, a finding that gives a matched odds ratio (adjusted for race, route of HIV infection, and CD4 count) of 0.08 (95% CI 0.01-0.84; p = 0.035) and indicates a 92% protective efficacy. We conclude that fluconazole reduces the risk of a first episode of cryptococcal meningitis in HIV-infected patients with a CD4 count less than 250/microL. Although the optimum dose and duration of fluconazole could not be determined, our results suggest that less than daily use was effective in the prevention of cryptococcal meningitis.

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).

Fluconazole for primary prophylaxis of AIDS-associated cryptococcosis: a case-control study

In order to verify whether fluconazole has a prophylactive effect against the occurrence of cryptococcosis in HIV-infected patients and to identify other factors capable of increasing or reducing the risk of this infection, we arranged a case-control study of 17 patients with cryptococcal infection. 34 controls were selected, matched by presence of an AIDS-defining event, CD4 cell count, and date of T-cell phenotyping. No significant difference in exposure to fluconazole, in total days of treatment, or in total dose administered was observed between cases and controls. However, control patients took a significantly higher average daily dosage of fluconazole and a linear tendency in risk reduction (p = 0.04) in relation to increasing dosage was observed. Antiretroviral therapy and an average daily fluconazole dose exceeding 150 mg both each reduced the risk of a cryptococcal infection.

Elevation of intracranial pressure in acute AIDS-related cryptococcal meningitis

Prior to the AIDS-era, elevation of intracranial pressure was known to be a typical complication of cryptococcal meningitis associated with an increased risk of early death. In AIDS-patients, however, the prevalence and clinical significance of this complication are as yet unclear. We analysed clinical features and courses, CSF findings, serological results and neuroimaging scans in acute cryptococcal meningitis in eight patients with AIDS. Five showed symptoms and signs compatible with raised intracranial pressure, which was life-threatening in one and the most probable cause of death in another. Serial monitoring of intracranial pressure together with repeated CSF analysis revealed that severe intracranial pressure elevation in AIDS related cryptococcal meningitis can occur in spite of effective antimycotic treatment, does not depend on an increased CSF/serum osmolality ratio or CSF overproduction and can be associated with normal cranial computed tomography and magnetic resonance imaging findings. Our data support the hypothesis that CSF reabsorption failure plays the crucial role in the pathophysiological mechanism. External lumbar drainage may be of benefit in selected cases of acute AIDS related cryptococcal meningitis with persisting life threatening elevation in intracranial pressure and normal computed tomogram.

Antifungal properties of essential oils and their main components upon Cryptococcus neoformans

Cryptococcus neoformans opportunistic fungus met in the last phasis of AIDS is inhibited in vitro by several essential oils on natural volatile compounds. The minimal inhibitory concentration may reach 100 microliters/l and minimal fungicidal concentration 200 microliters/l with Palmarosa or Cinnamon oils. Among phenolic compounds, thymol and carvacrol are most fungitoxic. Terpenoids, citral, geraniol, and citronellol show best activities.

Therapy for fungal infections

In the past, few pharmacologic agents were available for management of fungal disease. After the early introduction of amphotericin B and miconazole, the more recent advent of several new antifungal agents, including ketoconazole, fluconazole, and itraconazole has expanded the options for treatment of fungal infections. The dramatic increase in number of immunocompromised patients--both those with acquired immunodeficiency syndrome (AIDS) and those with immunosuppression for other reasons, such as organ transplantation--emphasizes the importance of therapeutic strategies for combating systemic mycoses. In this article, we review our personal recommendations for treating histoplasmosis, blastomycosis, coccidioidomycosis, and cryptococcosis, along with other less common fungal infections, and discuss the efficacy and toxic effects of the various antifungal drugs.

Management of systemic manifestations of fungal disease in patients with AIDS

In patients with AIDS with cryptococcosis, prompt diagnosis is essential. Poor results with conventional therapy (amphotericin-5FC) have led to exploration of the azoles. Both fluconazole and itraconazole have given good short-term results with less toxicity. However, cure is achieved far less often than in other compromised hosts. Fluconazole is also useful to prevent relapse after successful initial amphotericin therapy, particularly from genitourinary foci. In both histoplasmosis and aspergillosis, itraconazole has produced impressive therapeutic results, and in histoplasmosis, secondary prophylaxis as well. In coccidioidomycosis results thus far have not been better than conventional amphotericin therapy, especially in initial treatment.

Sterol composition of Cryptococcus neoformans in the presence and absence of fluconazole

Analysis of the sterol compositions of 13 clinical isolates of the pathogenic yeast Cryptococcus neoformans obtained from five patients with recurring cryptococcal meningitis showed that, unlike Candida albicans, the major sterols synthesized by this yeast were obtusifoliol (range, 21.1 to 68.2%) and ergosterol (range, 0.0 to 46.5%). There was considerable variation in the sterol contents among the 13 isolates, with total sterol contents ranging from 0.31 to 5.9% of dry weight. The isolates from the five patients who had relapses had different total sterol contents and compositions in comparison with those of the pretreatment isolates, indicating either that the sterols had been changed by therapy or that the patients were infected with new isolates with different sterol compositions. Growth of the cryptococcal isolates in the presence of subinhibitory concentrations of fluconazole (0.25x the MIC) significantly altered the sterol content and pattern. The total sterol content decreased in nine isolates and increased in four isolates in response to pretreatment with fluconazole. Fluconazole had no consistent effect on ergosterol levels. In contrast, fluconazole caused a decrease in obtusifoliol levels and an increase in 4,14-dimethylzymosterol levels in all isolates. These results indicate extensive diversity in sterol content, sterol composition, and sterol synthesis in response to subinhibitory concentrations of fluconazole in C. neoformans strains. We propose that fluconazole inhibits the sterol synthesis of C. neoformans by interfering with both 14 alpha-demethylase-dependent and -independent pathways. No correlation between the sterol compositions of C. neoformans isolates and their susceptibilities to fluconazole was found.

Morphological effects of lipopeptides against Aspergillus fumigatus correlate with activities against (1,3)-beta-D-glucan synthase

The lipopeptide antifungal agents, echinocandins, papulacandins, and pneumocandins, kill Candida albicans by inhibiting glucan synthesis. For this fungus, there is a good correlation of in vitro enzyme inhibition with in vitro assays of MICs. Semisynthetic lipopeptides such as cilofungin, LY303366, L-693,989, and L-733,560 have activity in vivo against Aspergillus infections but appear to be inactive in broth dilution in vitro tests (MICs, > 128 micrograms/ml). To understand how compounds which lack activity in vitro can have good in vivo activity, we monitored the effect of pneumocandins on the morphology of Aspergillus fumigatus and A, flavus strains by light microscopy and electron microscopy and related the changes in growth to inhibition of glucan synthesis. Pneumocandin B0 caused profound changes in hyphal growth; light micrographs showed abnormally swollen germ tubes, highly branched hyphal tips, and many cells with distended balloon shapes. Aspergillus electron micrographs confirmed that lipopeptides produce changes in cell walls; drug-treated germlings showed very stubby growth with thick walls and a conspicuous dark outer layer which was much thicker in the subapical regions. The rest of the hyphal tip ultrastructure was unaffected by the drug, indicating considerable specificity for the primary target. The drug-induced growth alteration produced very compact clumps in broth dilution wells, making it possible to score the morphological effect macroscopically. The morphological changes could be assayed quantitatively by using conventional broth microdilution susceptibility assay conditions. We defined the endpoint as the lowest concentration required to produce the morphological effect and called it the minimum effective concentration to distinguish it from the no-growth endpoints used in MIC determinations. The minimum effective concentration assay was related to inhibition of glucan synthase activity in vitro and may provide a starting point for development of susceptibility testing methods for lipopeptides.

The pharmacokinetics of fluconazole after a single intravenous dose in AIDS patients

The pharmacokinetics of fluconazole after a single 100 mg i.v. dose were studied in 10 healthy subjects (5 M; 5 F) and 10 HIV-positive patients (8 M; 2 F). The mean value of plasma clearance was 25% lower in the patient groups (17 +/- 6 (s.d.) vs 23 +/- 4 ml min-1; 95% CI of difference -11 to -0.7; P < 0.05). This difference may have been related to slightly reduced kidney function in the patient group (mean creatinine clearance -18%) but is unlikely to be clinically significant. Therefore, no adjustment of the dose of intravenously administered fluconazole appears to be necessary in AIDS patients without clinical signs of enteropathy.

Disseminated cryptococcosis in a patient with AIDS

We report the case of a 31-year-old AIDS patient who had generalized cryptococcal disease with involvement of the lungs, bone marrow, gastrointestinal tract and skin as well as chorioretinitis which may have been due also to Cryptococcus neoformans infection. Initially there was no involvement of the central nervous system. The patient recovered after 43 days' treatment with fluconazole and amphotericin B and flucytosine initially. Four months later he presented with a cryptococcal splenic abscess despite secondary prevention with fluconazole and twice-weekly liposomal amphotericin B. After splenectomy the patient was discharged in good health. One year later he died of cryptococcal meningitis.

Comparison of commercial kits for detection of cryptococcal antigen

Although kits to detect cryptococcal antigen are used widely to diagnose cryptococcal infection, the comparative performance of commercially available assays has not been evaluated in the past decade. Therefore, we compared the sensitives and specificities of five commercially available kits for detecting cryptococcal antigen (four latex agglutination test kits--Calas [Meridian Diagnostics])--Crypto-LA [International Biological Labs], Myco-Immune [MicroScan], and Immy [Immunomycologics]--and an enzyme immunoassay kit, Premier [Meridian Diagnostics]) with culture for the diagnosis of cryptococcal meningitis and fungemia. Of 182 cerebrospinal fluid (CSF) and 90 serum samples submitted for cryptococcal antigen and fungal culture, 49 (19 and 30 samples, respectively) from 20 patients had a culture positive for Cryptococcus neoformans. For CSF specimens, the sensitivities and specificities of all kits were comparable (sensitivity, 93 to 100%; specificity, 93 to 98%). There was a significant difference in sensitivities of the kits when serum samples were tested with the International Biological Labs and MicroScan kits, which do not pretreat serum with pronase. These kits were less sensitive (sensitivity, 83%) than the Immy and Meridian latex kits (sensitivity, 97%), which do pretreat with pronase. The sensitivity of the Meridian enzyme immunoassay kit was comparable to that of the pronase-containing latex kits. These kits were of equivalent specificities (93 to 100%) when testing serum. Some of the currently available kits have limitations that need to be recognized for proper interpretation of results. Specifically, the use of pronase on serum samples reduces the number of false-positive results, and a titer of < or = 1:4 can be a false-positive result when CSF samples are being tested.

Antifungal agents: an overview. Part II

The recent introduction of a new generation of antifungal drugs promises to alter significantly therapy for both systemic and superficial mycoses, in particular, onychomycosis. This article presents an in-depth review of the azoles (the triazoles itraconazole and fluconazole), the allylamines (naftifine and terbinafine), and the morpholine derivative amorolfine.

Comparison of broth dilution and semisolid agar dilution for in vitro susceptibility testing of Cryptococcus neoformans

We compared the in vitro activity of amphotericin B, flucytosine, itraconazole, fluconazole, ketoconazole and miconazole against 18 strains of Cryptococcus neoformans by using two methods: microbroth dilution and semisolid agar dilution. By both of the methods minimum inhibitory concentrations (MICs) showed a wide range for all antifungal agents but not for amphotericin B. Statistically significant differences between the two methods were observed only with amphotericin B and flucytosine, p = 0.048 and p = 0.045 respectively. Our study suggests that azole susceptibility testing for C. neoformans may be performed by the broth microdilution as well as the semisolid agar test. The choice of the method when testing amphotericin B and flucytosine is more problematic.

[Syndrome of macrophagic activation with hemophagocytosis in human immunodeficiency virus infection]

The authors report two cases of hematophagic histiocytosis in HIV positive patients. In the first case, a patient with Kaposi sarcoma and Mycobacterium avium infection had a rapidly deteriorating course with progressive pancytopenia and death, as generally described in the literature. In the second case, hematophagic histiocytosis appeared during HIV primo infection and reversed spontaneously. Although few cases of hemophagocytic syndrome have been reported in HIV positive patient, it could represent an underestimated cause of pancytopenia. Both opportunistic microorganisms and HIV are able to cause hematophagic histiocytosis.

Cutaneous involvement with Cryptococcus neoformans in AIDS

Patients infected with HIV are susceptible to many opportunistic fungal infections. Cryptococcus neoformans infection is particularly common in patients with AIDS. We describe a patient with disseminated cryptococcosis resembling molluscum contagiosum and review the typical cutaneous manifestations of disseminated cryptococcosis. A synopsis of case reports in the English literature is also presented.

Is there a correlation between serum antifungal drug concentration and clinical outcome?

Effective broad spectrum antifungal therapy has been available since the introduction of amphotericin B three decades ago. Amphotericin B must be given intravenously, and thus access to the bloodstream is assured. Because of the great toxicity of this agent, initial studies were directed at determining a dose which was tolerable and clinically effective. In part because of few data and in part because of major concerns with toxicity, there is at present no established relationship with amphotericin B serum concentrations and clinical outcome, and there is no clear indication for measurement of serum concentrations of this drug. More recently there has appeared a variety of orally administered antifungal azole derivatives. Oral absorption is affected by a variety of factors, and drug access to the blood stream is not readily predictable for some of these drugs. Serum concentrations have not been consistently assessed in clinical studies. Where they have been measured, there does appear to be a loose correlation of clinical response with the detection of some amount of drug in the bloodstream. However, beyond this 'threshold' concentration, there is no compelling evidence for a correlation of serum concentration and clinical outcome. While serum concentration of azoles may be useful in determining absorption of drug, at present there is no impetus for achieving a given concentration in the blood to improve chances of a good outcome.

Successful treatment of resistant cryptococcal meningitis with amphotericin B lipid emulsion after nephrotoxicity with conventional intravenous amphotericin B

Various formulations have been developed in an effort to reduce the toxicity of amphotericin B. We report a case of cryptococcal meningitis in a 31-year-old HIV-positive man which was successfully treated with amphotericin B lipid emulsion.