Short-course High-dose Liposomal Amphotericin B for Human Immunodeficiency Virus-associated Cryptococcal Meningitis: A Phase 2 Randomized Controlled Trial

Amphotericin B in the Era of New Antifungals: Where Will It Stand?

Amphotericin B (AmB) has long stood as a cornerstone in the treatment of invasive fungal infections (IFIs), especially among immunocompromised patients. However, the landscape of antifungal therapy is evolving. New antifungal agents, boasting novel mechanisms of action and better safety profiles, are entering the scene, presenting alternatives to AmB's traditional dominance. This shift, prompted by an increase in the incidence of IFIs, the growing demographic of immunocompromised individuals, and changing patterns of fungal resistance, underscores the continuous need for effective treatments. Despite these challenges, AmB's broad efficacy and low resistance rates maintain its essential status in antifungal therapy. Innovations in AmB formulations, such as lipid complexes and liposomal delivery systems, have significantly mitigated its notorious nephrotoxicity and infusion-related reactions, thereby enhancing its clinical utility. Moreover, AmB's efficacy in treating severe and rare fungal infections and its pivotal role as prophylaxis in high-risk settings highlight its value and ongoing relevance. This review examines AmB's standing amidst the ever-changing antifungal landscape, focusing on its enduring significance in current clinical practice and exploring its potential future therapeutic adaptations.

Safety of Single High-Dose Liposomal Amphotericin B for Induction Treatment of Cryptococcal Meningitis and Histoplasmosis in People With HIV: A Systematic Review and Meta-analysis

Background

Evidence for efficacy of single, high-dose liposomal amphotericin B (LAmB) in HIV-associated cryptococcal meningitis and histoplasmosis is growing. No systematic review has examined the safety of this regimen across multiple studies.

Methods

We systematically searched Medline, Scopus, and the Cochrane Library from inception to April 2023 for studies reporting grade 3 and 4 adverse events (AEs) with single high-dose LAmB vs traditional amphotericin regimens for HIV-associated fungal infections.

Results

Three trials (n = 946) were included. Compared with traditional regimens, single high-dose LAmB was associated with equivalent risk of grade 3 and 4 AEs (risk ratio [RR], 0.75; 95% CI, 0.53-1.06) and lower overall risk of grade 4 AEs (RR, 0.68; 95% CI, 0.55-0.86), grade 4 renal (RR, 0.43; 95% CI, 0.20-0.94) and grade 4 hematological AEs (RR, 0.46; 95% CI, 0.32-0.65).

Conclusions

Single, high-dose LAmB is associated with a lower risk of life-threatening AEs compared with other World Health Organization-endorsed amphotericin B-based regimens in invasive HIV-related fungal infection.

Therapy for HIV-associated cryptococcal meningitis: a case report demonstrating a new treatment approach emphasizing updated treatment guidelines

Cryptococcal meningitis (CM) remains a significant global health burden, especially for persons living with HIV. Despite effective antiretroviral and antifungal therapy, mortality rates are still approximately 70% in low- and middle-income countries and 20-30% in high-income countries. Central nervous system symptoms range from mild to severe, depending on burden of disease, and prompt and appropriate therapy is critical to reducing mortality. Treatment consists of three phases: induction, consolidation, and maintenance. Although treatment regimens have largely remained unchanged for decades, recent clinical trials have led the World Health Organization to update guidelines to reflect best practices in resource-limited settings. We review the clinical presentation, diagnosis, and standard therapy for CM, present a case with a challenging diagnostic and treatment course complicated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, and discuss the benefits of a new treatment dosing strategy highlighting potential advantages of adopting this novel dosing option in high-income countries.

How Applicable Is the Single-Dose AMBITION Regimen for Human Immunodeficiency Virus-Associated Cryptococcal Meningitis to High-Income Settings?

The AmBisome Therapy Induction Optimization (AMBITION-cm) trial, conducted in eastern and southern Africa, showed that a single, high dose (10 mg/kg) of liposomal amphotericin B, given with an oral backbone of fluconazole and flucytosine, was noninferior to the World Health Organization (WHO)-recommended regimen of 7 days of amphotericin B deoxycholate plus flucytosine for treatment of human immunodeficiency virus (HIV)-associated cryptococcal meningitis and has been incorporated into WHO treatment guidelines. We believe that the trial also has important implications for the treatment of HIV-associated cryptococcal meningitis in high-income settings. We advance the arguments, supported by evidence where available, that the AMBITION-cm trial regimen is likely to be as fungicidal as the currently recommended 14-day liposomal amphotericin-based treatments, better tolerated with fewer adverse effects, and confer significant economic and practical benefits and, therefore, should be included as a treatment option in guidance for HIV-associated cryptococcal treatment in high-income settings.

Comparative analysis of diagnostic methods for the detection of Cryptococcus neoformans meningitis

BACKGROUND

Cryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for the early diagnosis of meningitis due to C. neoformans, utilizing established molecular techniques from serum and CSF samples.

METHODS

The 18S and 5.8S (rDNA-ITS) sequence-specific nested PCR assays were compared with direct India ink staining and the latex agglutination test for detection of C. neoformans in serum and cerebrospinal fluid (CSF) from 49 Brazilian suspected meningitis patients. Results were validated with samples obtained from 10 patients negative for cryptococcosis and HIV, and by analysis of standard C. neoformans strains.

PRINCIPAL FINDINGS

The 5.8S DNA-ITS PCR was more sensitive (89-100%) and specific (100%) than the 18S rDNA PCR and conventional tests (India ink staining and latex agglutination) for identification of C. neoformans. While the 18S PCR exhibited a sensitivity (72%) similar to that of the latex agglutination assay in serum samples, it was superior to the latex agglutination assay when testing CSF, with a sensitivity of 84%. However, the latex agglutination was superior to the 18SrDNA PCR in specificity in CSF (92%). The 5.8S DNA-ITS PCR yielded the highest levels of accuracy (96-100%) of any test for detection (serological and mycological) of C. neoformans in both serum and CSF.

CONCLUSION

Use of the nested 5.8S PCR was superior to other techniques for the diagnosis of cryptococcosis. The possibility of using serum, a non-invasively collected material, in a targeted 5.8S PCR analysis to identify Cryptococcus spp. is recommended, especially in immunosuppressed patients. Our results indicate that nested 5.8S PCR can increase the diagnostic capability of cryptococcosis, and we suggest its use to monitor patients in the future.

Population pharmacokinetics of liposomal amphotericin B in adults with HIV-associated cryptococcal meningoencephalitis

BACKGROUND

Single, high-dose liposomal amphotericin B (LAmB; AmBisome, Gilead Sciences) has demonstrated non-inferiority to amphotericin B deoxycholate in combination with other antifungals for averting all-cause mortality from HIV-associated cryptococcal meningitis. There are limited data on the pharmacokinetics (PK) of AmBisome. The aim of this study was to describe population PK of AmBisome and conduct a meta-analysis of the available studies to suggest the optimal dosing for cryptococcal meningoencephalitis.

METHODS

Data from a Phase II and Phase III trial of high-dose, short-course AmBisome for cryptococcal meningoencephalitis were combined to develop a population PK model. A search was conducted for trials of AmBisome monotherapy and meta-analysis of clinical outcome data was performed.

RESULTS

A two-compartment model with first-order clearance of drug from the central compartment fitted the data best and enabled the extent of inter-individual variability in PK to be quantified. Mean (SD) population PK parameter estimates were: clearance 0.416 (0.363)  L/h; volume of distribution 4.566 (4.518) L; first-order transfer of drug from central to peripheral compartments 2.222 (3.351)  h-1, and from peripheral to central compartment 2.951 (4.070)  h-1. Data for the meta-analysis were insufficient to suggest optimal dosing of AmBisome for cryptococcal meningoencephalitis.

CONCLUSIONS

This study provides novel insight into the PK of AmBisome at the population level and the variability therein. Our analysis also serves to highlight the paucity of data available on the pharmacodynamics (PD) of AmBisome and underscores the importance of thorough and detailed PK/PD analysis in the development of novel antifungals, by demonstrating the challenges associated with post hoc PK/PD analysis.

Effectiveness of front line and emerging fungal disease prevention and control interventions and opportunities to address appropriate eco-sustainable solutions

Fungal pathogens contribute to significant disease burden globally; however, the fact that fungi are eukaryotes has greatly complicated their role in fungal-mediated infections and alleviation. Antifungal drugs are often toxic to host cells and there is increasing evidence of adaptive resistance in animals and humans. Existing fungal diagnostic and treatment regimens have limitations that has contributed to the alarming high mortality rates and prolonged morbidity seen in immunocompromised cohorts caused by opportunistic invasive infections as evidenced during HIV and COVID-19 pandemics. There is a need to develop real-time monitoring and diagnostic methods for fungal pathogens and to create a greater awareness as to the contribution of fungal pathogens in disease causation. Greater information is required on the appropriate selection and dose of antifungal drugs including factors governing resistance where there is commensurate need to discover more appropriate and effective solutions. Popular azole fungal drugs are widely detected in surface water and sediment due to incomplete removal in wastewater treatment plants where they are resistant to microbial degradation and may cause toxic effects on aquatic organisms such as algae and fish. UV has limited effectiveness in destruction of anti-fungal drugs where there is increased interest in the combination approaches such as novel use of pulsed-plasma gas-discharge technologies for environmental waste management. There is growing interest in developing alternative and complementary green eco-biocides and disinfection innovation. Fungi present challenges for cleaning, disinfection and sterilization of reusable medical devices such as endoscopes where they (example, Aspergillus and Candida species) can be protected when harboured in build-up biofilm from lethal processing. Information on the efficacy of established disinfection and sterilization technologies to address fungal pathogens including bottleneck areas that present high risk to patients is lacking. There is a need to address risk mitigation and modelling to inform efficacy of appropriate intervention technologies that must consider all contributing factors where there is potential to adopt digital technologies to enable real-time analysis of big data, such as use of artificial intelligence and machine learning. International consensus on standardised protocols for developing and reporting on appropriate alternative eco-solutions must be reached, particularly in order to address fungi with increasing drug resistance where research and innovation can be enabled using a One Health approach.

The acceptability of the AMBITION-cm treatment regimen for HIV-associated cryptococcal meningitis: Findings from a qualitative methods study of participants and researchers in Botswana and Uganda

BACKGROUND

The AMBITION-cm trial for HIV-associated cryptococcal meningitis demonstrated that a single, high-dose of liposomal amphotericin (AmBisome) plus 14-days of oral flucytosine and fluconazole was non-inferior in terms of all-cause mortality to 7-days of amphotericin B deoxycholate and flucytosine followed by 7-days of fluconazole (Control). The AmBisome regimen was associated with fewer adverse events. We explored the acceptability of the AmBisome regimen from the perspective of participants and providers.

METHODS

We embedded a qualitative methods study within the AMBITION-cm sites in Botswana and Uganda. We conducted in-depth interviews with trial participants, surrogate decision makers, and researchers and combined these with direct observations. Interviews were transcribed, translated, and analysed thematically.

RESULTS

We interviewed 38 trial participants, 20 surrogate decision makers, and 31 researchers. Participant understanding of the trial was limited; however, there was a preference for the AmBisome regimen due to the single intravenous dose and fewer side effects. More time was required to prepare the single AmBisome dose but this was felt to be acceptable given subsequent reductions in workload. The AmBisome regimen was reported to be associated with fewer episodes of rigors and thrombophlebitis and a reduction in the number of intravenous cannulae required. Less intensive monitoring and management was required for participants in the AmBisome arm.

CONCLUSIONS

The AmBisome regimen was highly acceptable, being simpler to administer despite the initial time investment required. The regimen was well tolerated and associated with less toxicity and resultant management. Widespread implementation would reduce the clinical workload of healthcare workers caring for patients with HIV-associated cryptococcal meningitis.

Treatment of Cryptococcal Meningitis: How Have We Got Here and Where are We Going?

Cryptococcal meningitis is a devastating brain infection cause by encapsulated yeasts of the Cryptococcus genus. Exposure, through inhalation, is likely universal by adulthood, but symptomatic infection only occurs in a minority, in most cases, months or years after exposure. Disease has been described in almost all tissues, but it is the organism’s tropism for the central nervous system that results in the most devastating illness. While invasive disease can occur in the immunocompetent, the greatest burden by far is in immunocompromised individuals, particularly people living with human immunodeficiency virus (HIV), organ transplant recipients and those on glucocorticoid therapy or other immunosuppressive drugs. Clinical presentation is variable, but diagnosis is usually straightforward, with cerebrospinal fluid microscopy, culture, and antigen testing proving significantly more sensitive than diagnostic tests for other brain infections. Although disease incidence has reduced since the advent of effective HIV therapy, mortality when disease occurs remains extremely high, and has changed little in recent decades. This Therapy in Practice review is an update of a talk first given by JND at the European Congress on Clinical Microbiology and Infectious Diseases in 2019 in the Netherlands. The review contextualizes the most recently published World Health Organization (WHO) guidelines for the treatment of HIV-associated cryptococcal meningitis in terms of the data from large, randomized, controlled trials published between 1997 and 2022. We discuss the rationale for induction and maintenance therapy and the efficacy and undesirable effects of the current therapeutic armamentarium of amphotericin, flucytosine and fluconazole. We address recent research into repurposed drugs such as sertraline and tamoxifen, and potential future treatment options, including the novel antifungals fosmanogepix, efungumab and oteseconazole, and non-pharmaceutical solutions such as neurapheresis cerebrospinal fluid filtration.

Cryptococcus spp. and Cryptococcosis: focusing on the infection in Brazil

Cryptococcosis is a global fungal infection caused by the Cryptococcus neoformans/Cryptococcus gattii yeast complex. This infection is acquired by inhalation of propagules such as basidiospores or dry yeast, initially causing lung infections with the possibility of progressing to the meninges. This infection mainly affects immunocompromised HIV and transplant patients; however, immunocompetent patients can also be affected. This review proposes to evaluate cryptococcosis focusing on studies of this mycosis in Brazilian territory; moreover, recent advances in the understanding of its virulence mechanism, animal models in research are also assessed. For this, literature review as realized in PubMed, Scielo, and Brazilian legislation. In Brazil, cryptococcosis has been identified as one of the most lethal fungal infections among HIV patients and C. neoformans VNI and C. gattii VGII are the most prevalent genotypes. Moreover, different clinical settings published in Brazil were described. As in other countries, cryptococcosis is difficult to treat due to a limited therapeutic arsenal, which is highly toxic and costly. The presence of a polysaccharide capsule, thermo-tolerance, production of melanin, biofilm formation, mechanisms for iron use, and morphological alterations is an important virulence mechanism of these yeasts. The introduction of cryptococcosis as a compulsory notification disease could improve data regarding incidence and help in the management of these infections.

Single-Dose Liposomal Amphotericin B Treatment for Cryptococcal Meningitis

BACKGROUND

Cryptococcal meningitis is a leading cause of human immunodeficiency virus (HIV)-related death in sub-Saharan Africa. Whether a treatment regimen that includes a single high dose of liposomal amphotericin B would be efficacious is not known.

METHODS

In this phase 3 randomized, controlled, noninferiority trial conducted in five African countries, we assigned HIV-positive adults with cryptococcal meningitis in a 1:1 ratio to receive either a single high dose of liposomal amphotericin B (10 mg per kilogram of body weight) on day 1 plus 14 days of flucytosine (100 mg per kilogram per day) and fluconazole (1200 mg per day) or the current World Health Organization-recommended treatment, which includes amphotericin B deoxycholate (1 mg per kilogram per day) plus flucytosine (100 mg per kilogram per day) for 7 days, followed by fluconazole (1200 mg per day) for 7 days (control). The primary end point was death from any cause at 10 weeks; the trial was powered to show noninferiority at a 10-percentage-point margin.

RESULTS

A total of 844 participants underwent randomization; 814 were included in the intention-to-treat population. At 10 weeks, deaths were reported in 101 participants (24.8%; 95% confidence interval [CI], 20.7 to 29.3) in the liposomal amphotericin B group and 117 (28.7%; 95% CI, 24.4 to 33.4) in the control group (difference, -3.9 percentage points); the upper boundary of the one-sided 95% confidence interval was 1.2 percentage points (within the noninferiority margin; P<0.001 for noninferiority). Fungal clearance from cerebrospinal fluid was -0.40 log10 colony-forming units (CFU) per milliliter per day in the liposomal amphotericin B group and -0.42 log10 CFU per milliliter per day in the control group. Fewer participants had grade 3 or 4 adverse events in the liposomal amphotericin B group than in the control group (50.0% vs. 62.3%).

CONCLUSIONS

Single-dose liposomal amphotericin B combined with flucytosine and fluconazole was noninferior to the WHO-recommended treatment for HIV-associated cryptococcal meningitis and was associated with fewer adverse events. (Funded by the European and Developing Countries Clinical Trials Partnership and others; Ambition ISRCTN number, ISRCTN72509687.).

Cost-effectiveness of single-dose AmBisome preemptive treatment for the prevention of cryptococcal meningitis in African low and middle-income countries

Cryptococcal antigen (CrAg) screening is recommended for patients with advanced HIV to reduce AIDS-related mortality. For asymptomatic CrAg-positive persons, fluconazole preemptive therapy is standard, despite a ∼25% failure rate. Single-dose liposomal amphotericin B (AmBisome) is non-inferior to standard treatment for cryptococcal meningitis. We evaluate the threshold of efficacy necessary for AmBisome + fluconazole to be cost-effective as preemptive therapy for CrAg-positive persons. We created a decision analytic model to evaluate CrAg screening and treatment in HIV-infected persons with CD4 < 100 cells/µL. Costs were estimated for screening, preemptive therapy, and hospitalization for an example low-income country (Uganda) and middle-income country (South Africa). We used a discounted price range of AmBisome® at ${\$}$16.25 to ${\$}$40 per 50 mg vial for both Uganda and South Africa. We estimated AmBisome efficacy from 75% to 95%. Parameter assumptions were based on prospective CrAg screening studies and clinical trials in Africa. Disability adjusted life years (DALYs) were calculated using the age-specific life expectancy in Uganda, per WHO Global Health Observatory data. We modeled the theoretical efficacy of adjunctive AmBisome to determine cost per DALY averted. In South Africa, at ${\$}$16.25 per vial cost and a minimum efficacy of 85%, adjunctive AmBisome is cost-saving compared to fluconazole monotherapy. Compared to fluconazole preemptive therapy in Uganda, AmBisome + fluconazole would cost ${\$}$475, ${\$}$220, or ${\$}$136 per DALY averted if meningitis-free survival efficacy was 80%, 85%, or 90% at ${\$}$24 per vial cost. Investing in AmBisome may be cost-effective in low-income settings compared to using fluconazole preemptive therapy alone, if efficacy is 85% or greater. AmBisome preemptive therapy appears more cost-efficient in middle-income settings where hospitalization costs for meningitis, and GDP per capita are higher.

Fungal CNS Infections in Africa: The Neuroimmunology of Cryptococcal Meningitis

Cryptococcal meningitis (CM) is the leading cause of central nervous system (CNS) fungal infections in humans, with the majority of cases reported from the African continent. This is partly due to the high burden of HIV infection in the region and reduced access to standard-of-care including optimal sterilising antifungal drug treatments. As such, CM is responsible for 10-15% of all HIV-related mortality, with a large proportion being preventable. Immunity to the causative agent of CM, Cryptococcus neoformans, is only partially understood. IFNγ producing CD4⁺ T-cells are required for the activation of myeloid cells, especially macrophages, to enable fungal killing and clearance. However, macrophages may also act as a reservoir of the fungal yeast cells, shielding them from host immune detection thus promoting latent infection or persistent chronic inflammation. In this chapter, we review the epidemiology and pathogenesis of CNS fungal infections in Africa, with a major focus on CM, and the antifungal immune pathways operating to protect against C. neoformans infection. We also highlight the areas of research and policy that require prioritisation to help reduce the burden of CNS fungal diseases in Africa.

Consensus guidelines for the diagnosis and management of cryptococcosis and rare yeast infections in the haematology/oncology setting, 2021

Cryptococcosis caused by the Cryptococcus neoformans-Cryptococcus gattii complex is an important opportunistic infection in people with immunodeficiency, including in the haematology/oncology setting. This may manifest clinically as cryptococcal meningitis or pulmonary cryptococcosis, or be detected incidentally by cryptococcal antigenemia, a positive sputum culture or radiological imaging. Non-Candida, non-Cryptococcus spp. rare yeast fungaemia are increasingly common in this population. These consensus guidelines aim to provide clinicians working in the Australian and New Zealand haematology/oncology setting with clear guiding principles and practical recommendations for the management of cryptococcosis, while also highlighting important and emerging rare yeast infections and their recommended management.

Combination Therapy for HIV-Associated Cryptococcal Meningitis-A Success Story

Cryptococcal meningitis is the leading cause of adult meningitis in patients with HIV, and accounts for 15% of all HIV-related deaths in sub-Saharan Africa. The mainstay of management is effective antifungal therapy, despite a limited arsenal of antifungal drugs, significant progress has been made developing effective treatment strategies by using combination regimens. The introduction of fluconazole as a safe and effective step-down therapy allowed for shorter courses of more fungicidal agents to be given as induction therapy, with higher doses achieving more rapid CSF sterilisation and improved treatment outcomes. The development of early fungicidal activity (EFA), an easily measured surrogate of treatment efficacy, has enabled rapid identification of effective combinations through dose ranging phase II studies, allowing further evaluation of clinical benefit in targeted phase III studies. Recent clinical trials have shown that shorter course induction regimens using one week of amphotericin paired with flucytosine are non-inferior to traditional two-week induction regimens and that the combination of fluconazole and flucytosine offers a viable treatment alternative when amphotericin is unavailable. Access to drugs in many low and middle-income settings remains challenging but is improving, and novel strategies based on single high dose liposomal amphotericin B promise further reduction in treatment complications and toxicities. This review aims to summarise the key findings of the principal clinical trials that have led to the success story of combination therapy thus far.

Cost-effectiveness of cryptococcal antigen screening at CD4 counts of 101-200 cells/µL in Botswana

Background: Cryptococcal antigen (CrAg) screening in individuals with advanced HIV reduces cryptococcal meningitis (CM) cases and deaths. The World Health Organization recently recommended increasing screening thresholds from CD4 ≤100 cells/µL to ≤200 cells/µL. CrAg screening at CD4 ≤100 cells/µL is cost-effective; however, the cost-effectiveness of screening patients with CD4 101-200 cells/µL requires evaluation. Methods: Using a decision analytic model with Botswana-specific cost and clinical estimates, we evaluated CrAg screening and treatment among individuals with CD4 counts of 101-200 cells/µL. We estimated the number of CM cases and deaths nationally and treatment costs without screening. For screening we modeled the number of CrAg tests performed, number of CrAg-positive patients identified, proportion started on pre-emptive fluconazole, CM cases and deaths. Screening and treatment costs were estimated and cost per death averted or disability-adjusted life year (DALY) saved compared with no screening. Results: Without screening, we estimated 142 CM cases and 85 deaths annually among individuals with CD4 101-200 cells/µL, with treatment costs of $368,982. With CrAg screening, an estimated 33,036 CrAg tests are performed, and 48 deaths avoided (1,017 DALYs saved).  While CrAg screening costs an additional $155,601, overall treatment costs fall by $39,600 (preemptive and hospital-based CM treatment), yielding a net increase of $116,001. Compared to no screening, high coverage of CrAg screening and pre-emptive treatment for CrAg-positive individuals in this population avoids one death for $2440 and $114 per DALY saved. In sensitivity analyses assuming a higher proportion of antiretroviral therapy (ART)-naïve patients (75% versus 15%), cost per death averted was $1472; $69 per DALY saved. Conclusions: CrAg screening for individuals with CD4 101-200 cells/µL was estimated to have a modest impact, involve additional costs, and be less cost-effective than screening populations with CD4 counts ≤100 cells/µL. Additional CrAg screening costs must be considered against other health system priorities.

Strategies for the diagnosis and management of meningitis in HIV-infected adults in resource limited settings

INTRODUCTION

The incidence of human immunodeficiency virus-1 (HIV-1) associated meningitis has been declining in the post-combination antiretroviral treatment (ART) era, although survival rates remain low for the common causes like tuberculosis and cryptococcal disease. Diagnosis and treatment of meningitis in HIV-1 is complicated by atypical clinical presentations, limited accuracy of diagnostic tests, access to diagnostic tests, and therapeutic agents in low- and middle-income countries (LMIC) and immune reconstitution inflammatory syndrome (IRIS).

AREAS COVERED

We provide an overview of the common etiologies of meningitis in HIV-1-infected adults, suggest a diagnostic approach based on readily available tests, and review specific chemotherapeutic agents, host-directed therapies, supportive care, timing of ART initiation, and considerations in the management of IRIS with a focus on resource-limited settings. They identify key knowledge gaps and suggest areas for future research.

EXPERT OPINION

Evidence-based management of HIV-1-associated meningitis is sparse for common etiologies. More readily available and sensitive diagnostic tests as well as standardized investigation strategies are required in LMIC. There is a lack of availability of recommended drugs in areas of high HIV-1 prevalence and a limited pipeline of novel chemotherapeutic agents. Host-directed therapies have been inadequately studied.

Cryptococcosis

Cryptococcosis is an invasive fungal infection of global significance caused by yeasts of the genus Cryptococcus. The prevalence of HIV in certain areas of the world and the expanding population of immunocompromised patients contribute to the ongoing global disease burden. Point-of-care serologic testing has allowed for more rapid diagnosis and implementation of screening programs in resource-limited settings. Management involves therapy aimed at reduction in fungal burden, maintenance of intracranial pressure, and optimization of host immunity. Despite diagnostic and therapeutic advances, cryptococcosis continues to be a disease with unacceptably high incidence and mortality, particularly in resource-limited settings.

Screening for Cryptococcal Antigenemia and Burden of Cryptococcosis at the Time of HIV Diagnosis: A Retrospective Multicenter Study

Introduction

Screening for cryptococcal antigen (CrAg) is recommended for people living with HIV (PLWH) who present with low CD4 lymphocyte counts. Real-world experience is important to identify gaps between the guidelines and clinical practice. We investigated the trends of CrAg testing and prevalence of cryptococcal antigenemia among PLWH at the time of HIV diagnosis and the related mortality in Taiwan from 2009 to 2018.

Methods

Medical records of newly diagnosed PLWH seeking care at six medical centers around Taiwan between 2009 and 2018 were reviewed. The annual trends of PLWH who had CrAg testing and cryptococcal antigenemia were examined by Cochran-Armitage test. Among PLWH with CD4 < 200 cells/µl, timing of CrAg testing was analyzed for association with 12-month all-cause mortality in Kaplan-Meier plots and in a Cox proportional hazards model after adjustments.

Results

Among 5372 included PLWH, 1150 (21.4%) presented with baseline CD4 < 100 cells/µl, and this proportion had decreased during the study period [from 108 (29.3%) in 2009 to 93 (22.3%) in 2018 (P = 0.039)]. The overall prevalence of cryptococcal antigenemia was 7.8% among PLWH with CD4 < 100 cells/µl, which remained stable during the 10-year study period (P = 0.356) and was 2.6% among PLWH with CD4 100–199 cells/µl. The uptake of CrAg testing had increased from 65.7% in 2009 to 78.0% in 2018 (P = 0.002) among PLWH with CD4 < 100 cells/µl. Late CrAg testing, defined by 14 days or later after HIV diagnosis, was associated with increased risk of 12-month mortality compared to early CrAg testing (adjusted hazard ratio 2.028, 95% CI 1.109–3.708).

Conclusions

Burden of cryptococcosis remained high among PLWH with low CD4 lymphocyte counts in Taiwan. Uptake of CrAg screening among late HIV presenters was still suboptimal and delayed. Late CrAg testing was associated with a higher mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00451-5.

Equity in clinical trials for HIV-associated cryptococcal meningitis: A systematic review of global representation and inclusion of patients and researchers

Background

It is essential that clinical trial participants are representative of the population under investigation. Using HIV-associated cryptococcal meningitis (CM) as a case study, we conducted a systematic review of clinical trials to determine how inclusive and representative they were both in terms of the affected population and the involvement of local investigators.

Methods

We searched Medline, EMBASE, Cochrane, Africa-Wide, CINAHL Plus, and Web of Science. Data were extracted for 5 domains: study location and design, screening, participants, researchers, and funders. Data were summarised and compared over 3 time periods: pre-antiretroviral therapy (ART) (pre-2000), early ART (2000 to 2009), and established ART (post-2010) using chi-squared and chi-squared for trend. Comparisons were made with global disease burden estimates and a composite reference derived from observational studies.

Results

Thirty-nine trials published between 1990 and 2019 were included. Earlier studies were predominantly conducted in high-income countries (HICs) and recent studies in low- and middle-income countries (LMICs). Most recent studies occurred in high CM incidence countries, but some highly affected countries have not hosted trials. The sex and ART status of participants matched those of the general CM population. Patients with reduced consciousness and those suffering a CM relapse were underrepresented. Authorship had poor representation of women (29% of all authors), particularly as first and final authors. Compared to trials conducted in HICs, trials conducted in LMICs were more likely to include female authors (32% versus 20% p = 0.014) but less likely to have authors resident in (75% versus 100%, p < 0.001) or nationals (61% versus 93%, p < 0.001) of the trial location.

Conclusions

There has been a marked shift in CM trials over the course of the HIV epidemic. Trials are primarily performed in locations and populations that reflect the burden of disease, but severe and relapse cases are underrepresented. Most CM trials now take place in LMICs, but the research is primarily funded and led by individuals and institutions from HICs.

It is essential that clinical trial participants are representative of the population under investigation. Similarly, research must meaningfully include researchers who are from and/or based in the location where the study is being conducted, both to ensure that the research matches the local need but also to promote equity in research. Using clinical trials in HIV-associated cryptococcal meningitis as a case study, we conducted a systematic review to determine how inclusive and representative trials have been across the course of the HIV epidemic. We identified 39 studies. There was a geographical shift with trials moving from the USA to Africa and Asia over time. We found that recent trials were conducted in areas heavily affected by cryptococcal meningitis, but we did identify geographical areas and patient groups that have been underrepresented. We also found inequality within authorship that was skewed towards male researchers from high-income countries. These findings outline areas for our discipline to focus on. We can also use this study as a benchmark from which to monitor our progress over time. This is a broad methodology that could be adopted and adapted by other research groups.

High burden of cryptococcal antigenemia and meningitis among patients presenting at an emergency department in Maputo, Mozambique

BACKGROUND

Cryptococcal meningitis is a leading cause of HIV-related mortality in sub-Saharan Africa, however, screening for cryptococcal antigenemia has not been universally implemented. As a result, data concerning cryptococcal meningitis and antigenemia are sparse, and in Mozambique, the prevalence of both are unknown.

METHODS

We performed a retrospective analysis of routinely collected data from a point-of-care cryptococcal antigen screening program at a public hospital in Maputo, Mozambique. HIV-positive patients admitted to the emergency department underwent CD4 count testing; those with pre-defined abnormal vital signs or CD4 count ≤ 200 cells/μL received cryptococcal antigen testing and lumbar punctures if indicated. Patients with CM were admitted to the hospital and treated with liposomal amphotericin B and flucytosine; their 12-week outcomes were ascertained through review of medical records or telephone contact by program staff made in the routine course of service delivery.

RESULTS

Among 1,795 patients screened for cryptococcal antigenemia between March 2018-March 2019, 134 (7.5%) were positive. Of patients with cryptococcal antigenemia, 96 (71.6%) were diagnosed with CM, representing 5.4% of all screened patients. Treatment outcomes were available for 87 CM patients: 24 patients (27.6%) died during induction treatment and 63 (72.4%) survived until discharge; of these, 38 (60.3%) remained in care, 9 (14.3%) died, and 16 (25.3%) were lost-to follow-up at 12 weeks.

CONCLUSIONS

We found a high prevalence of cryptococcal antigenemia and meningitis among patients screened at an emergency department in Maputo, Mozambique. High mortality during and after induction therapy demonstrate missed opportunities for earlier detection of cryptococcal antigenemia, even as point-of-care screening and rapid assessment in an emergency room offer potential to improve outcomes.

Efficacy of induction regimens for cryptococcal meningitis in HIV-infected adults: a systematic review and network meta-analysis

Cryptococcal meningitis (CM) is the most fatal adult meningitis in patients with human immunodeficiency virus (HIV). There is no conclusive evidence for the superiority of 1-week amphotericin B deoxycholate (AmphB) + flucytosine (5-FC) regimen over other antifungals in the management of HIV patients with CM (HIV-CM patients). We aimed to evaluate the differences in efficacy and tolerability of different antifungal agents in HIV-CM patients by conducting a current network meta-analysis NMA. Overall, 19 randomized controlled trials were included with 2642 participants. A regimen indicated a possibly lower early mortality rate, namely, AmphB + 5-FC + Azole (OR = 1.1E-12, 95% CIs = 1.3E-41 to 0.06) comparing to AmphB + 5-FC. The current NMA provides evidence that AmphB + 5-FC + Azole are superior to all the investigated treatments for induction regimen in HIV-CM patients.

CNS infections in HIV

PURPOSE OF REVIEW

Central nervous system (CNS) infections associated with HIV remain significant contributors to morbidity and mortality, particularly among people living with HIV (PLWH) in resource-limited settings worldwide. In this review, we discuss several recent important scientific discoveries in the prevention, diagnosis, and management around two of the major causes of CNS opportunistic infections-tuberculous meningitis (TBM) and cryptococcal meningitis including immune reconstitution syndrome (IRIS) associated with cryptococcal meningitis. We also discuss the CNS as a possible viral reservoir, highlighting Cerebrospinal fluid viral escape.

RECENT FINDINGS

CNS infections in HIV-positive people in sub-Saharan Africa contribute to 15-25% of AIDS-related deaths. Morbidity and mortality in those is associated with delays in HIV diagnosis, lack of availability for antimicrobial treatment, and risk of CNS IRIS. The CNS may serve as a reservoir for replication, though it is unclear whether this can impact peripheral immunosuppression.

SUMMARY

Significant diagnostic and treatment advances for TBM and cryptococcal meningitis have yet to impact overall morbidity and mortality according to recent data. Lack of early diagnosis and treatment initiation, and also maintenance on combined antiretroviral treatment are the main drivers of the ongoing burden of CNS opportunistic infections. The CNS as a viral reservoir has major potential implications for HIV eradication strategies, and also control of CNS opportunistic infections.

Cost-effectiveness of cryptococcal antigen screening at CD4 counts of 101-200 cells/µL in Botswana

Background: Cryptococcal antigen (CrAg) screening in individuals with advanced HIV reduces cryptococcal meningitis (CM) cases and deaths. The World Health Organization recently recommended increasing screening thresholds from CD4 ≤100 cells/µL to ≤200 cells/µL. CrAg screening at CD4 ≤100 cells/µL is cost-effective; however, the cost-effectiveness of screening patients with CD4 101-200 cells/µL requires evaluation. Methods: Using a decision analytic model with Botswana-specific cost and clinical estimates, we evaluated CrAg screening and treatment among individuals with CD4 counts of 101-200 cells/µL. We estimated the number of CM cases and deaths nationally and treatment costs without screening. For screening we modeled the number of CrAg tests performed, number of CrAg-positive patients identified, proportion started on pre-emptive fluconazole, CM cases and deaths. Screening and treatment costs were estimated and cost per death averted or disability-adjusted life year (DALY) saved compared with no screening. Results: Without screening, we estimated 142 CM cases and 85 deaths annually among individuals with CD4 101-200 cells/µL, with treatment costs of $368,982. With CrAg screening, an estimated 33,036 CrAg tests are performed, and 48 deaths avoided (1,017 DALYs saved).  While CrAg screening costs an additional $155,601, overall treatment costs fall by $39,600 (preemptive and hospital-based CM treatment), yielding a net increase of $116,001. Compared to no screening, high coverage of CrAg screening and pre-emptive treatment for CrAg-positive individuals in this population avoids one death for $2440 and $114 per DALY saved. In sensitivity analyses assuming a higher proportion of antiretroviral therapy (ART)-naïve patients (75% versus 15%), cost per death averted was $1472; $69 per DALY saved. Conclusions: CrAg screening for individuals with CD4 101-200 cells/µL was estimated to have a modest impact, involve additional costs, and be less cost-effective than screening populations with CD4 counts ≤100 cells/µL. Additional CrAg screening costs must be considered against other health system priorities.

Osteoarticular Cryptococcosis Successfully Treated with High-Dose Liposomal Amphotericin B Followed by Oral Fluconazole

Background

Skeletal involvement of Cryptococcus neoformans is infrequent and usually associated with disseminated cryptococcosis or underlying predisposing conditions. We present an atypical case of osteoarticular cryptococcosis in an immunocompetent patient.

Case Presentation

We herein report a case of bone and soft tissue cryptococcal infection in a 42-year-old male from Pakistan with well-controlled diabetes without other associated immunodeficiencies treated with antifungal therapy without surgical debridement. Furthermore, the patient developed toxidermia due to fluconazole use, so a fluconazole desensitization was performed. Therapeutic management also included the performance of therapeutic drug monitoring of fluconazole plasma concentrations.

Conclusion

To our knowledge, this is the first case of osteoarticular cryptococcosis treated with this treatment regimen. This strategy may be of interest to try to reduce hospital stay and associated complications.

Comparative Transcriptome Analysis of Streptomyces nodosus Mutant With a High-Yield Amphotericin B

Antibiotics play an important role in human health. Most antibiotics are derived from microbial secondary metabolites. Amphotericin is a polyene macrolide antibiotic synthesized by Streptomyces nodosus. S. nodosus ZJB2016050 with high-yield amphotericin B (AmB) was obtained by traditional mutagenesis using S. nodosus ATCC14899 as the original strain. The differences in the characterization of the two strains were found in color, mycelium morphology, and AmB yield. Subsequent comparative transcriptome explained the yield differences between the two strains. Pathways including the carbohydrate metabolic pathway and the secondary product synthesis pathway were targeted. The upregulation of glucokinase, phosphoglycerate mutase, and pyruvate dehydrogenase accelerates the consumption of glucose and has great effects on the accumulation of precursors. One of the competitive secondary metabolites of the polyketone synthetase (PKS) II type sapromomycin analog synthesis gene cluster was downregulated, which competes for malonyl-CoA. Five PKS modules (except for the first module amphA) of the amphotericin synthetic gene cluster in the high-yielding strain were downregulated, which resulted in the total amphotericin A (AmA) and AmB of S. nodosus ZJB2016050 being less than that of the wild-type S. nodosus ATCC14899. Combined with gene differential expression in the pentose phosphate pathway and the reaction mechanism of the ER5 domain, the reason that S. nodosus ZJB2016050 preferred to synthesize AmB was probably related to intracellular reduction.

Treatment strategies for cryptococcal infection: challenges, advances and future outlook

Cryptococcus spp., in particular Cryptococcus neoformans and Cryptococcus gattii, have an enormous impact on human health worldwide. The global burden of cryptococcal meningitis is almost a quarter of a million cases and 181,000 deaths annually, with mortality rates of 100% if infections remain untreated. Despite these alarming statistics, treatment options for cryptococcosis remain limited, with only three major classes of drugs approved for clinical use. Exacerbating the public health burden is the fact that the only new class of antifungal drugs developed in decades, the echinocandins, displays negligible antifungal activity against Cryptococcus spp., and the efficacy of the remaining therapeutics is hampered by host toxicity and pathogen resistance. Here, we describe the current arsenal of antifungal agents and the treatment strategies employed to manage cryptococcal disease. We further elaborate on the recent advances in our understanding of the intrinsic and adaptive resistance mechanisms that are utilized by Cryptococcus spp. to evade therapeutic treatments. Finally, we review potential therapeutic strategies, including combination therapy, the targeting of virulence traits, impairing stress response pathways and modulating host immunity, to effectively treat infections caused by Cryptococcus spp. Overall, understanding of the mechanisms that regulate anti-cryptococcal drug resistance, coupled with advances in genomics technologies and high-throughput screening methodologies, will catalyse innovation and accelerate antifungal drug discovery.

Diagnostic Accuracy of the Biosynex CryptoPS Cryptococcal Antigen Semiquantitative Lateral Flow Assay in Patients with Advanced HIV Disease

High cryptococcal antigen (CrAg) titers in blood are associated with subclinical meningitis and mortality in CrAg-positive individuals with advanced HIV disease (AHD). We evaluated a novel semiquantitative lateral flow assay (LFA), CryptoPS, that may be able to identify individuals with high CrAg titers in a cohort of AHD patients undergoing CrAg screening. In a prospective cohort of patients with AHD (CD4 cell count, ≤200/μl) receiving CD4 count testing, whole blood was tested for CrAg by CryptoPS and the IMMY LFA; the two assays were conducted by two different operators, each blind to the results of the other assay.

High cryptococcal antigen (CrAg) titers in blood are associated with subclinical meningitis and mortality in CrAg-positive individuals with advanced HIV disease (AHD). We evaluated a novel semiquantitative lateral flow assay (LFA), CryptoPS, that may be able to identify individuals with high CrAg titers in a cohort of AHD patients undergoing CrAg screening. In a prospective cohort of patients with AHD (CD4 cell count, ≤200/μl) receiving CD4 count testing, whole blood was tested for CrAg by CryptoPS and the IMMY LFA; the two assays were conducted by two different operators, each blind to the results of the other assay. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CryptoPS were assessed against the IMMY LFA as a reference. CryptoPS low-titer (T1 band) and high-titer (T2 band) results were compared with IMMY LFA titers obtained through serial dilution. A total of 916 specimens were tested. The sensitivity of the CryptoPS assay was 61.0% (25/41) (95% confidence interval [95% CI], 44.5 to 75.8%), its specificity was 96.6% (845/875) (95% CI, 95.1 to 97.7%), its PPV was 45.5% (95% CI, 32.0 to 59.4%), and its NPV was 98.1% (95% CI, 97.0 to 98.9%). All (16/16) CryptoPS false-negative results were obtained for samples with IMMY titers of ≤1:160. Of 29 patients (30 specimens) who tested positive by CryptoPS but negative by the IMMY LFA, none developed cryptococcal meningitis over 3 months of follow-up without fluconazole. Median CrAg titers were 1:20 (interquartile range [IQR], 0 to 1:160) in CryptoPS T1-positive samples and 1:2,560 (IQR, 1:1,280 to 1:10,240) in T2-positive samples. We conclude that the diagnostic accuracy of the CryptoPS assay was suboptimal in the context of CrAg screening, with poor sensitivity at low CrAg titers. However, the CryptoPS assay reliably detected individuals with high titers, which are associated with poor outcomes.

A Novel Cryptococcal Meningitis Therapy: The Combination of Amphotericin B and Posaconazole Promotes the Distribution of Amphotericin B in the Brain Tissue

The deficient brain tissue distribution of amphotericin B (AMPB) seriously restricts its treatment for the clinical efficacy of cryptococcus neoformans meningitis (CNM). We strive to develop a tactic to increase its concentration in brain tissue. We aimed to investigate whether the combination of AMPB and posaconazole (POS) could be more effective in the treatment of CNM and to elucidate its potential mechanisms. HPLC analysis was used to analyze the concentration of AMPB in mouse serum, brain tissue, and BCECs cells. Schrodinger molecular docking, in vitro plasma balance dialysis, and ultrafiltration analysis were performed to evaluate the combinative effect of AMPB and POS with serum albumin and POS on AMPB plasma protein binding. H&E staining and colonization culture experiment of CN were employed to assess the effect of POS on the efficacy of AMPB. POS + AMPB significantly reduced the concentration of plasma total AMPB and increased its concentration in the brain tissue. However, the P-gp inhibitor zosuquidar, BCRP inhibitor Ko143, and a common inhibitor of both, elacridar, had no significant effect on its concentration. Molecular docking, balance dialysis, and ultrafiltration analysis showed that AMPB and POS had potential binding properties to serum albumin. Meanwhile, 4 and 8 μg/mL POS could significantly increase the concentration of free AMPB in plasma. POS and three inhibitors all had no significant effect on the uptake of AMPB by BCECs, but serum albumin had. The therapeutic effect of CNM in mice was confirmed that AMPB and AMPB+POS could restrain the infiltration of neutrophils and lymphocytes in cortical neurons and improve the bleeding and markedly inhibit the proliferation of CN. Collectively, we propose that POS competitively binds to the plasma protein sites of AMPB, thereby increasing its level in the brain tissue. Meanwhile, POS could enhance the efficacy of AMPB in the treatment of CNM, which may be independent of P-gp and BCRP proteins.

HIV-1C env and gag Variation in the Cerebrospinal Fluid and Plasma of Patients with HIV-Associated Cryptococcal Meningitis in Botswana

HIV-1 compartmentalization in reservoir sites remains a barrier to complete HIV eradication. It is unclear whether there is variation in HIV-1 env and gag between cerebrospinal fluid (CSF) and plasma of individuals with HIV-associated cryptococcal meningitis (CM). We compared HIV-1 env characteristics and the gag cytotoxic T-lymphocyte (CTL) escape mutations from CSF and plasma samples. Employing population-based Sanger sequencing, we sequenced HIV-1 env from CSF of 25 patients and plasma of 26 patients. For gag, 15 CSF and 21 plasma samples were successfully sequenced. Of these, 18 and 9 were paired env and gag CSF/plasma samples, respectively. There was no statistically significant difference in the proportion of CCR5-using strains in the CSF and plasma, (p = 0.50). Discordant CSF/plasma virus co-receptor use was found in 2/18 pairs (11.1%). The polymorphisms in the HIV-1 V3 loop were concordant between the two compartments. From the HIV-1 gag sequences, three pairs had discordant CTL escape mutations in three different epitopes of the nine analyzed. These findings suggest little variation in the HIV-1 env between plasma and CSF and that the CCR5-using strains predominate in both compartments. HIV-1 gag CTL escape mutations also displayed little variation in CSF and plasma suggesting similar CTL selective pressure.

HIV-associated Cryptococcal Meningitis: a Review of Novel Short-Course and Oral Therapies

Purpose of review

HIV-associated cryptococcal meningitis remains a significant public health problem in parts of Africa and Asia and a major cause of AIDS-related mortality, accounting for 15% of all AIDS-related deaths worldwide. Cryptococcal meningitis is uniformly fatal if untreated, and access to antifungal therapy in regions with the highest burden is often limited. Outcomes with fluconazole monotherapy are poor, and induction treatment with amphotericin B and high-dose fluconazole for 2 weeks is associated with significant drug-related toxicities and prolonged hospital admissions. This review focuses on the potential of novel short-course and oral combination therapies for cryptococcal meningitis.

Recent findings

Recent clinical trials have shown that shorter courses of amphotericin, if paired with oral flucytosine, rather than fluconazole, can achieve non-inferior mortality outcomes. In addition, an oral combination of fluconazole and flucytosine is a potential alternative. Liposomal amphotericin B may further simplify treatment; it is associated with fewer drug-related toxicities, and a recent phase II randomised controlled trial demonstrated that a single, high dose of liposomal amphotericin is non-inferior to 14 standard daily doses at clearing Cryptococcus from cerebrospinal fluid. This has been taken forward to an ongoing phase III, clinical endpoint study.

Summary

The incidence and mortality associated with cryptococcal meningitis is still unacceptably high. There is evidence supporting the use of short-course amphotericin B and oral combination antifungal treatment regimens for cryptococcal meningitis (CM). Ongoing research into short-course, high-dose treatment with liposomal amphotericin may also help reduce the impact of this devastating disease.

Differences in human immunodeficiency virus-1C viral load and drug resistance mutation between plasma and cerebrospinal fluid in patients with human immunodeficiency virus-associated cryptococcal meningitis in Botswana

To determine effects of cryptococcal meningitis (CM) on human immunodeficiency virus (HIV)-1C cerebrospinal fluid (CSF) viral escape, CSF/plasma viral discordance, and drug resistance mutation (DRM) discordance between CSF and plasma compartments, we compared CSF and plasma viral load (VL) and DRMs in individuals with HIV-associated CM in Botswana.This cross-sectional study utilized 45 paired CSF/plasma samples from participants in a CM treatment trial (2014-2016). HIV-1 VL was determined and HIV-1 protease and reverse transcriptase genotyping performed. DRMs were determined using the Stanford HIV database. CSF viral escape was defined as HIV-1 ribonucleic acid ≥0.5 log10 higher in CSF than plasma and VL discordance as CSF VL > plasma VL.HIV-1 VL was successfully measured in 39/45 pairs, with insufficient sample volume in 6; 34/39 (87.2%) participants had detectable HIV-1 in plasma and CSF, median 5.1 (interquartile range: 4.7-5.7) and 4.6 (interquartile range:3.7-4.9) log10 copies/mL, respectively (P≤.001). CSF viral escape was present in 1/34 (2.9%) and VL discordance in 6/34 (17.6%). Discordance was not associated with CD4 count, antiretroviral status, fungal burden, CSF lymphocyte percentage nor mental status. Twenty-six of 45 (57.8%) CSF/plasma pairs were successfully sequenced. HIV-1 DRM discordance was found in 3/26 (11.5%); 1 had I84IT and another had M46MI in CSF only. The third had K101E in plasma and V106 M in CSF.Our findings suggest that HIV-1 escape and DRM discordance may occur at lower rates in participants with advanced HIV-disease and CM compared to those with HIV associated neurocognitive impairment.

Evaluation of a Novel Semiquantitative Cryptococcal Antigen Lateral Flow Assay in Patients with Advanced HIV Disease

Higher cryptococcal antigen (CrAg) titers are strongly associated with mortality risk in individuals with HIV-associated cryptococcal disease. Rapid tests to quantify CrAg levels may provide important prognostic information and enable treatment stratification. We performed a laboratory-based validation of the IMMY semiquantitative cryptococcal antigen (CrAgSQ) lateral flow assay (LFA) against the current gold standard CrAg tests. We assessed the diagnostic accuracy of the CrAgSQ in HIV-positive individuals undergoing CrAg screening, determined the relationship between CrAgSQ scores and dilutional CrAg titers, assessed interrater reliability, and determined the clinical correlates of CrAgSQ scores.

Higher cryptococcal antigen (CrAg) titers are strongly associated with mortality risk in individuals with HIV-associated cryptococcal disease. Rapid tests to quantify CrAg levels may provide important prognostic information and enable treatment stratification. We performed a laboratory-based validation of the IMMY semiquantitative cryptococcal antigen (CrAgSQ) lateral flow assay (LFA) against the current gold standard CrAg tests. We assessed the diagnostic accuracy of the CrAgSQ in HIV-positive individuals undergoing CrAg screening, determined the relationship between CrAgSQ scores and dilutional CrAg titers, assessed interrater reliability, and determined the clinical correlates of CrAgSQ scores. A total of 872 plasma samples were tested using both the CrAgSQ LFA and the conventional IMMY CrAg LFA, of which 692 were sequential samples from HIV-positive individuals undergoing CrAg screening and an additional 180 were known CrAg-positive plasma samples archived from prior studies. Interrater agreement in CrAgSQ reading was excellent (98.17% agreement, Cohen’s kappa 0.962, P < 0.001). Using the IMMY CrAg LFA as a reference standard, CrAgSQ was 93.0% sensitive (95% confidence interval [CI] 80.9% to 98.5%) and 93.8% specific (95% CI, 91.7% to 95.6%). After reclassification of discordant results using CrAg enzyme immunoassay testing, the sensitivity was 98.1% (95% CI, 90.1% to 100%) and specificity 95.8% (95% CI, 93.9% to 97.2%). The median CrAg titers for semiquantitative score categories (1+ to 4+) were 1:10 (interquartile range [IQR], 1:5 to 1:20) in the CrAgSQ 1+ category, 1:40 (IQR, 1:20 to 1:80) in the CrAgSQ 2+ category, 1:640 (IQR, 1:160 to 1:2,560) in the CrAgSQ 3+ category, and 1:5,120 (IQR, 1:2,560 to 1:30,720) in the CrAgSQ 4+ category. Increasing CrAgSQ scores were strongly associated with 10-week mortality. The IMMY CrAgSQ test had high sensitivity and specificity compared to the results for the IMMY CrAg LFA and provided CrAg scores that were associated with both conventional CrAg titers and clinical outcomes.

Cryptococcal meningitis: a review of cryptococcal antigen screening programs in Africa

INTRODUCTION

Cryptococcal meningitis remains a significant contributor to AIDS-related mortality despite widened access to antiretroviral therapy. Cryptococcal antigen (CrAg) can be detected in the blood prior to development of meningitis. Development of highly sensitive and specific rapid diagnostic CrAg tests has helped facilitate the adoption of CrAg screening programs in 19 African countries.

AREAS COVERED

The biological rationale for CrAg screening and the programmatic strategies for its implementation are reviewed. We describe the approach to the investigation of patients with cryptococcal antigenemia and the importance of lumbar puncture to identify individuals who may have cryptococcal meningitis in the absence of symptoms. The limitations of current treatment recommendations and the potential role of newly defined combination antifungal therapies are discussed. A literature review was conducted using a broad database search for cryptococcal antigen screening and related terms in published journal articles dating up to December 2019. Conference abstracts, publicly available guidelines, and project descriptions were also incorporated.

EXPERT OPINION

As we learn more about the risks of cryptococcal antigenemia, it has become clear that the current management paradigm is inadequate. More intensive investigation and management are required to prevent the development of cryptococcal meningitis and reduce mortality associated with cryptococcal antigenemia.

What Is the Most Appropriate Induction Regimen for the Treatment of HIV-Associated Cryptococcal Meningitis When the Recommended Regimen Is Not Available? Evidence From a Network Meta-Analysis

Aims

Our object was to find the most appropriate, most effective, and most readily available of four induction regimens for HIV-associated cryptococcal meningitis (CM) (Regimen A: 1 week of AmB plus 5-FC followed by 1 week of fluconazole, Regimen B: 1 week of AmB plus fluconazole followed by 1 week of fluconazole, Regimen C: 2 weeks of AmB plus 5-FC, Regimen D: 2 weeks of AmB plus fluconazole), given the vast differences between resource-limited and resource-abundant settings regarding therapeutic drug accessibility, availability, and affordability for HIV-associated (CM).

Methods

We conducted a network meta-analysis to compare the therapeutic efficacy and safety of four different induction treatment regimens.

Results

The 10-week mortality of Regimen A was significantly lower than that of Regimen B and D, and the 2-week mortality of Regimen A was significantly lower than that of Regimen B. Furthermore, there were no statistically significant differences in 10-week mortality, 2-week mortality, as well as in effective fungicidal activity (EFA) over the first 2 weeks among Regimens B, C, and D. The statistical differences in adverse events between Regimen B and Regimen D, and Regimen C and Regimen D were not calculated to be significant.

Conclusions

Our results indicate that, 1 week of AmB plus 5-FC followed by 1 week of fluconazole is superior to the three other studied regimens, and that when 5-FC is not available, accessible, or affordable, 2 weeks of AmB plus fluconazole or 1 week of AmB plus fluconazole followed by 1 week of fluconazole is an appropriate substitution for 2 weeks of AmB plus 5-FC.

Treatment of invasive fungal diseases in cancer patients-Revised 2019 Recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Invasive fungal diseases remain a major cause of morbidity and mortality in cancer patients undergoing intensive cytotoxic therapy. The choice of the most appropriate antifungal treatment (AFT) depends on the fungal species suspected or identified, the patient's risk factors (eg length and depth of granulocytopenia) and the expected side effects.

OBJECTIVES

Since the last edition of recommendations for 'Treatment of invasive fungal infections in cancer patients' of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) in 2013, treatment strategies were gradually moving away from solely empirical therapy of presumed or possible invasive fungal diseases (IFDs) towards pre-emptive therapy of probable IFD.

METHODS

The guideline was prepared by German clinical experts for infections in cancer patients in a stepwise consensus process. MEDLINE was systematically searched for English-language publications from January 1975 up to September 2019 using the key terms such as 'invasive fungal infection' and/or 'invasive fungal disease' and at least one of the following: antifungal agents, cancer, haematological malignancy, antifungal therapy, neutropenia, granulocytopenia, mycoses, aspergillosis, candidosis and mucormycosis.

RESULTS

AFT of IFDs in cancer patients may include not only antifungal agents but also non-pharmacologic treatment. In addition, the armamentarium of antifungals for treatment of IFDs has been broadened (eg licensing of isavuconazole). Additional antifungals are currently under investigation or in clinical trials.

CONCLUSIONS

Here, updated recommendations for the treatment of proven or probable IFDs are given. All recommendations including the levels of evidence are summarised in tables to give the reader rapid access to key information.

Mortality from HIV-associated meningitis in sub-Saharan Africa: a systematic review and meta-analysis

INTRODUCTION

HIV-associated cryptococcal, TB and pneumococcal meningitis are the leading causes of adult meningitis in sub-Saharan Africa (SSA). We performed a systematic review and meta-analysis with the primary aim of estimating mortality from major causes of adult meningitis in routine care settings, and to contrast this with outcomes from clinical trial settings.

METHODS

We searched PubMed, EMBASE and the Cochrane Library for published clinical trials (defined as randomized-controlled trials (RCTs) or investigator-managed prospective cohorts) and observational studies that evaluated outcomes of adult meningitis in SSA from 1 January 1990 through 15 September 2019. We performed random effects modelling to estimate pooled mortality, both in clinical trial and routine care settings. Outcomes were stratified as short-term (in-hospital or two weeks), medium-term (up to 10 weeks) and long-term (up to six months).

RESULTS AND DISCUSSION

Seventy-nine studies met inclusion criteria. In routine care settings, pooled short-term mortality from cryptococcal meningitis was 44% (95% confidence interval (95% CI):39% to 49%, 40 studies), which did not differ between amphotericin (either alone or with fluconazole) and fluconazole-based induction regimens, and was twofold higher than pooled mortality in clinical trials using amphotericin based treatment (21% (95% CI:17% to 25%), 17 studies). Pooled short-term mortality of TB meningitis was 46% (95% CI: 33% to 59%, 11 studies, all routine care). For pneumococcal meningitis, pooled short-term mortality was 54% in routine care settings (95% CI:44% to 64%, nine studies), with similar mortality reported in two included randomized-controlled trials. Few studies evaluated long-term outcomes.

CONCLUSIONS

Mortality rates from HIV-associated meningitis in SSA are very high under routine care conditions. Better strategies are needed to reduce mortality from HIV-associated meningitis in the region.

Epidemiology of adult meningitis during antiretroviral therapy scale-up in southern Africa: Results from the Botswana national meningitis survey

OBJECTIVES

Data on meningitis epidemiology in high HIV-prevalence African settings following antiretroviral therapy scale-up are lacking. We described epidemiology of adult meningitis in Botswana over a 16-year period.

METHODS

Laboratory records for adults undergoing lumbar puncture (LP) 2000-2015 were collected, with complete national data 2013-2014. Cerebrospinal fluid (CSF) findings and linked HIV-data were described, and national incidence figures estimated for 2013-2014. Temporal trends in meningitis were evaluated.

RESULTS

Of 21,560 adults evaluated, 41% (8759/21,560) had abnormal CSF findings with positive microbiological testing and/or pleocytosis; 43% (3755/8759) of these had no confirmed microbiological diagnosis. Of the 5004 microbiologically-confirmed meningitis cases, 89% (4432/5004) were cryptococcal (CM) and 8% (382/5004) pneumococcal (PM). Seventy-three percent (9525/13,033) of individuals undergoing LP with identifiers for HIV registry linkage had documented HIV-infection. Incidence of LP for meningitis evaluation in Botswana 2013-2014 was 142.6/100,000 person-years (95%CI:138.3-147.1); incidence of CM was 25.0/100,000 (95%CI:23.2-26.9), and incidence of PM was 2.7/100,000 (95%CI:2.4-3.1). In contrast to previously reported declines in CM incidence with ART roll-out, no significant temporal decline in pneumococcal or culture-negative meningitis was observed.

CONCLUSIONS

CM remained the predominant identified aetiology of meningitis despite ART scale-up. A high proportion of cases had abnormal CSF with negative microbiological evaluation.

Release of different amphotericin B formulations from PMMA bone cements and their activity against Candida biofilm

Amphotericin B is used for local delivery from polymethylmethacrylate to treat fungal prosthetic joint infections. The optimal amphotericin B formulation and the influence of different poragens in the bone cements are unknown. To investigate the necessary amount of amphotericin B in the bone cement to prevent Candida biofilm several amphotericin B formulations were studied: non-liposomal and liposomal with or without poragen gentamicin. For the non-liposomal formulation, standard bile salt, the sodium deoxycholate, was used and additionally N-methyl-D-glucamine/palmitate was applied. The activity of the released amphotericin B was tested against C. albicans, C. glabrata, C. parapsilosis and C. krusei biofilms with application of the isothermal calorimeter and standard microbiological methods. Compressive strength was measured before and after antifungal elution from the cements. There is less aggregated N-methyl-D-glucamine/palmitate amphotericin B released but its antifungal activity is equivalent with the deoxycholate amphotericin B. The minimum quantity of antifungal preventing the Candida biofilm formation is 12.5 mg in gram of polymer powder for both non-liposomal formulations. The addition of gentamicin reduced the release of sodium deoxycholate amphotericin B. Gentamicin can be added to N-methyl-D-glucamine/palmitate amphotericin B in order to boost the antifungal release. When using liposomal amphotericin B more drug is released. All amphotericin B formulations were active against Candida biofilms. Although compressive strength slightly decreased, the obtained values were above the level of strength recommended for the implant fixation. The finding of this work might be beneficial for the treatment of the prosthetic joint infections caused by Candida spp.

Management of amphotericin-induced phlebitis among HIV patients with cryptococcal meningitis in a resource-limited setting: a prospective cohort study

BACKGROUND

Amphotericin-induced phlebitis is a common infusion-related reaction in patients managed for cryptococcal meningitis. High-quality nursing care is critical component to successful cryptococcosis treatment. We highlight the magnitude and main approaches in the management of amphotericin-induced phlebitis and the challenges faced in resource-limited settings.

METHODS

We prospectively determined the incidence of amphotericin-induced phlebitis during clinical trials in Kampala, Uganda from 2013 to 2018. We relate practical strategies and challenges faced in clinical management of phlebitis.

RESULTS

Overall, 696 participants were diagnosed with HIV-related cryptococcal meningitis. Participants received 7-14 doses of intravenous (IV) amphotericin B deoxycholate 0.7-1.0 mg/kg/day for induction therapy through peripheral IV lines at a concentration of 0.1 mg/mL in 5% dextrose. Overall, 18% (125/696) developed amphotericin-induced phlebitis. We used four strategies to minimize/prevent the occurrence of phlebitis. First, after every dose of amphotericin, we gave one liter of intravenous normal saline. Second, we rotated IV catheters every three days. Third, we infused IV amphotericin over 4 h. Finally, early ambulation was encouraged to minimize phlebitis. To alleviate phlebitis symptoms, warm compresses were used. In severe cases, treatment included topical diclofenac gel and oral anti-inflammatory medicines. Antibiotics were used only when definite signs of infection developed. Patient/caregivers' education was vital in implementing these management strategies. Major challenges included implementing these interventions in participants with altered mental status and limited access to topical and oral anti-inflammatory medicines in resource-limited settings.

CONCLUSIONS

Amphotericin-induced phlebitis is common with amphotericin, yet phlebitis is a preventable complication even in resource-limited settings.

TRIAL REGISTRATION

The ASTRO-CM trial was registered prospectively. ClincalTrials.gov : NCT01802385 ; Registration date: March 1, 2013; Last verified: February 14, 2018.

Recent advances in managing HIV-associated cryptococcal meningitis

The recent development of highly sensitive and specific point-of-care tests has made it possible to diagnose HIV-associated cryptococcal meningitis within minutes. However, diagnostic advances have not been matched by new antifungal drugs and treatment still relies on old off-patent drugs: amphotericin B, flucytosine and fluconazole. Cryptococcal meningitis treatment is divided in three phases: induction, consolidation and maintenance. The induction phase, aimed at drastically reducing cerebrospinal fluid fungal burden, is key for patient survival. The major challenge in cryptococcal meningitis management has been the optimisation of induction phase treatment using the limited number of available medications, and major progress has recently been made. In this review, we summarise data from key trials which form the basis of current treatment recommendations for HIV-associated cryptococcal meningitis.

Clinical Pharmacokinetics, Pharmacodynamics, Safety and Efficacy of Liposomal Amphotericin B

Since its introduction in the 1990s, liposomal amphotericin B (LAmB) continues to be an important agent for the treatment of invasive fungal diseases caused by a wide variety of yeasts and molds. This liposomal formulation was developed to improve the tolerability of intravenous amphotericin B, while optimizing its clinical efficacy. Since then, numerous clinical studies have been conducted, collecting a comprehensive body of evidence on its efficacy, safety, and tolerability in the preclinical and clinical setting. Nevertheless, insights into the pharmacokinetics and pharmacodynamics of LAmB continue to evolve and can be utilized to develop strategies that optimize efficacy while maintaining the compound's safety. In this article, we review the clinical pharmacokinetics, pharmacodynamics, safety, and efficacy of LAmB in a wide variety of patient populations and in different indications, and provide an assessment of areas with a need for further clinical research.

AMBIsome Therapy Induction OptimisatioN (AMBITION): High dose AmBisome for cryptococcal meningitis induction therapy in sub-Saharan Africa: economic evaluation protocol for a randomised controlled trial-based equivalence study

INTRODUCTION

Cryptococcal meningitis is responsible for around 15% of all HIV-related deaths globally. Conventional treatment courses with amphotericin B require prolonged hospitalisation and are associated with multiple toxicities and poor outcomes. A phase II study has shown that a single high dose of liposomal amphotericin may be comparable to standard treatment. We propose a phase III clinical endpoint trial comparing single, high-dose liposomal amphotericin with the WHO recommended first-line treatment at six sites across five counties. An economic analysis is essential to support wide-scale implementation.

METHODS AND ANALYSIS

Country-specific economic evaluation tools will be developed across the five country settings. Details of patient and household out-of-pocket expenses and any catastrophic healthcare expenditure incurred will be collected via interviews from trial patients. Health service patient costs and related household expenditure in both arms will be compared over the trial period in a probabilistic approach, using Monte Carlo bootstrapping methods. Costing information and number of life-years survived will be used as the input to a decision-analytic model to assess the cost-effectiveness of a single, high-dose liposomal amphotericin to the standard treatment. In addition, these results will be compared with a historical cohort from another clinical trial.

ETHICS AND DISSEMINATION

The AMBIsome Therapy Induction OptimisatioN (AMBITION) trial has been evaluated and approved by the London School of Hygiene and Tropical Medicine, University of Botswana, Malawi National Health Sciences, University of Cape Town, Mulago Hospital and Zimbabwe Medical Research Council research ethics committees. All participants will provide written informed consent or if lacking capacity will have consent provided by a proxy. The findings of this economic analysis, part of the AMBITION trial, will be disseminated through peer-reviewed publications and at international and country-level policy meetings.

TRIAL REGISTRATION

ISRCTN 7250 9687; Pre-results.