Angela Loyse

Global burden of disease of HIV-associated cryptococcal meningitis: an updated analysis

BACKGROUND Cryptococcus is the most common cause of meningitis in adults living with HIV in sub-Saharan Africa. Global burden estimates are crucial to guide prevention strategies and to determine treatment needs, and we aimed to provide an updated estimate of global incidence of HIV-associated cryptococcal disease. METHODS We used 2014 Joint UN Programme on HIV and AIDS estimates of adults (aged >15 years) with HIV and antiretroviral therapy (ART) coverage. Estimates of CD4 less than 100 cells per μL, virological failure incidence, and loss to follow-up were from published multinational cohorts in low-income and middle-income countries. We calculated those at risk for cryptococcal infection, specifically those with CD4 less than 100 cells/μL not on ART, and those with CD4 less than 100 cells per μL on ART but lost to follow-up or with virological failure. Cryptococcal antigenaemia prevalence by country was derived from 46 studies globally. Based on cryptococcal antigenaemia prevalence in each country and region, we estimated the annual numbers of people who are developing and dying from cryptococcal meningitis. FINDINGS We estimated an average global cryptococcal antigenaemia prevalence of 6·0% (95% CI 5·8-6·2) among people with a CD4 cell count of less than 100 cells per μL, with 278 000 (95% CI 195 500-340 600) people positive for cryptococcal antigen globally and 223 100 (95% CI 150 600-282 400) incident cases of cryptococcal meningitis globally in 2014. Sub-Saharan Africa accounted for 73% of the estimated cryptococcal meningitis cases in 2014 (162 500 cases [95% CI 113 600-193 900]). Annual global deaths from cryptococcal meningitis were estimated at 181 100 (95% CI 119 400-234 300), with 135 900 (75%; [95% CI 93 900-163 900]) deaths in sub-Saharan Africa. Globally, cryptococcal meningitis was responsible for 15% of AIDS-related deaths (95% CI 10-19). INTERPRETATION Our analysis highlights the substantial ongoing burden of HIV-associated cryptococcal disease, primarily in sub-Saharan Africa. Cryptococcal meningitis is a metric of HIV treatment programme failure; timely HIV testing and rapid linkage to care remain an urgent priority. FUNDING None.

High-Dose Amphotericin B with Flucytosine for the Treatment of Cryptococcal Meningitis in HIV-Infected Patients: A Randomized Trial

BACKGROUND The standard therapy for human immunodeficiency virus (HIV)-associated cryptococcal meningitis of amphotericin B (AmB; 0.7 mg/kg per day) plus flucytosine frequently takes >2 weeks to sterilize the cerebral spinal fluid, and acute mortality remains high. A dosage range for AmB of 0.7-1 mg/kg per day is noted in current guidelines, but there are no data comparing 0.7 mg/kg per day with 1 mg/kg per day. METHODS Sixty-four HIV-seropositive, antiretroviral therapy-naive patients in Cape Town, South Africa, who experienced their first episode of cryptococcal meningitis during the period May 2005-June 2006 were randomized to receive either (1) AmB, 0.7 mg/kg per day, plus flucytosine, 25 mg/kg 4 times per day (group 1; 30 patients); or (2) AmB, 1 mg/kg per day, plus flucytosine, 25 mg/kg 4 times per day (group 2; 34 patients). Regimens were given for 2 weeks, followed by treatment with oral fluconazole. The primary outcome measure was early fungicidal activity, as determined by results of serial, quantitative cerebral spinal fluid cryptococcal cultures. Secondary outcome measures were safety and mortality. The median duration of follow-up was 1 year. RESULTS Early fungicidal activity was significantly greater for group 2 than for group 1 (mean +/- SD, -0.56 +/- 0.24 vs. -0.45 +/- 0.16 log cfu/mL of cerebral spinal fluid per day; P = .02). The incidence of renal impairment did not significantly differ between the 2 groups. Anemia was associated with female sex and, less strongly, with membership in group 2. Renal impairment and anemia reversed after the regimen was switched to fluconazole. Two- and 10-week mortality rates were 6% and 24%, respectively, with no difference between groups. CONCLUSIONS AmB, 1 mg/kg per day, plus flucytosine is more rapidly fungicidal than is standard-dose AmB plus flucytosine. Because of its size, this study provides limited data on any difference in toxicity between the regimens, but toxicities were manageable and reversible. CLINICAL TRIALS REGISTRATION NUMBER ISRCTN68133435 (http://www.controlled-trials.com).

Immune reconstitution inflammatory syndrome in HIV-associated cryptococcal meningitis: a prospective study.

Background:Prospective data on incidence, characteristics, and risk factors for cryptococcal meningitis immune reconstitution inflammatory syndrome (CM-IRIS) are lacking. Methods:Prospective study of 65 antiretroviral therapy (ART)-naive HIV-infected cryptococcal meningitis (CM) patients, who started ART after initiation of antifungal treatment. CM-IRIS definition: (1) cerebrospinal fluid (CSF) culture-confirmed CM, (2) symptom resolution before starting ART, (3) adherence to fluconazole and ART, (4) recurrence of CM symptoms after starting ART, (5) immunologic and/or virologic response to ART, (6) no alternative diagnosis. Results:ART was started at a median of 47 days from CM diagnosis. CM-IRIS developed in 11 of 65 (17%), at a median 29 days from starting ART. No factors at first CM episode (fungal burden, rate of clearance, CSF, or HIV parameters) predicted those at risk of CM-IRIS. At 6 months on ART, IRIS patients had greater CD4 rise from baseline (220 vs. 124 × 106 cells /L in non-IRIS, P = 0.01), and 4 of 11 CM-IRIS patients died compared with 14 of 54 non-IRIS patients (P = 0.5). For those developing CM-IRIS, CSF proinflammatory cytokines interferon γ, tumour necrosis factor α, and interleukin 6, did not differ between first CM and CM-IRIS episode. Conclusions:Patients with CM-IRIS had greater immune restoration in response to ART. Although common and potentially fatal, larger prospective studies are needed to determine whether CM-IRIS, in patients treated initially with amphotericin B, is associated with any increase in overall mortality.

Determinants of Mortality in a Combined Cohort of 501 Patients With HIV-Associated Cryptococcal Meningitis: Implications for Improving Outcomes.

Cerebrospinal fluid fungal burden, altered mental status, and rate of clearance of infection predict acute mortality in HIV-associated cryptococcal meningitis. The identification of factors associated with mortality informs strategies to improve outcomes.

Independent association between rate of clearance of infection and clinical outcome of HIV-associated cryptococcal meningitis: analysis of a combined cohort of 262 patients.

BACKGROUND Progress in therapy for cryptococcal meningitis has been slow because of the lack of a suitable marker of treatment response. Previously, we demonstrated the statistical power of a novel endpoint, the rate of clearance of infection, based on serial quantitative cultures of cerebrospinal fluid, to differentiate the fungicidal activity of alternative antifungal drug regimens. We hypothesized that the rate of clearance of infection should also be a clinically meaningful endpoint. METHODS We combined data from cohorts of patients with human immunodeficiency virus-associated cryptococcal meningitis from Thailand, South Africa, and Uganda, for whom the rate of clearance of infection was determined, and clinical and laboratory data prospectively collected, and explored the association between the rate of clearance of infection and mortality by Cox survival analyses. RESULTS The combined cohort comprised 262 subjects. Altered mental status at presentation, a high baseline organism load, and a slow rate of clearance of infection were independently associated with increased mortality at 2 and 10 weeks. Rate of clearance of infection was associated with antifungal drug regimen and baseline cerebrospinal fluid interferon-gamma levels. CONCLUSIONS The results support the use of the rate of clearance of infection or early fungicidal activity as a means to explore antifungal drug dosages and combinations in phase II studies. An increased understanding of how the factors determining outcome interrelate may help clarify opportunities for intervention.

Relationship of cerebrospinal fluid pressure, fungal burden and outcome in patients with cryptococcal meningitis undergoing serial lumbar punctures

Objectives:To assess impact of serial lumbar punctures on association between cerebrospinal fluid (CSF) opening pressure and prognosis in HIV-associated cryptococcal meningitis; to explore time course and relationship of opening pressure with neurological findings, CSF fungal burden, immune response, and CD4 cell count. Design:Evaluation of 163 HIV-positive ART-naive patients enrolled in three trials of amphotericin B-based therapy for cryptococcal meningitis in Thailand and South Africa. Methods:Study protocols required four lumbar punctures with measurements of opening pressure over the first 2 weeks of treatment and additional lumbar punctures if opening pressure raised. Fungal burden and clearance, CSF immune parameters, CD4 cell count, neurological symptoms and signs, and outcome at 2 and 10 weeks were compared between groups categorized by opening pressure at cryptococcal meningitis diagnosis. Results:Patients with higher baseline fungal burden had higher baseline opening pressure. High fungal burden appeared necessary but not sufficient for development of high pressure. Baseline opening pressure was not associated with CD4 cell count, CSF pro-inflammatory cytokines, or altered mental status. Day 14 opening pressure was associated with day 14 fungal burden. Overall mortality was 12% (20/162) at 2 weeks and 26% (42/160) at 10 weeks, with no significant differences between opening pressure groups. Conclusion:Studies are needed to define factors, in addition to fungal burden, associated with raised opening pressure. Aggressive management of raised opening pressure through repeated CSF drainage appeared to prevent any adverse impact of raised opening pressure on outcome in patients with cryptococcal meningitis. The results support increasing access to manometers in resource-poor settings and routine management of opening pressure in patients with cryptococcal meningitis.

Comparison of the Early Fungicidal Activity of High-Dose Fluconazole, Voriconazole, and Flucytosine as Second-Line Drugs Given in Combination With Amphotericin B for the Treatment of HIV-Associated Cryptococcal Meningitis

BACKGROUND HIV-associated cryptococcal meningitis is associated with an estimated 600 000 deaths worldwide per year. Current standard initial therapy consists of amphotericin B (AmB) plus flucytosine (5-FC), but 5-FC remains largely unavailable in Asia and Africa. Alternative, more widely available, and/or more effective antifungal combination treatment regimens are urgently needed. METHODS Eighty HIV-seropositive, antiretroviral naive patients presenting with cryptococcal meningitis were randomized to 4 treatment arms of 2 weeks duration: group 1, AmB (0.7-1 mg/kg) and 5-FC (25 mg/kg 4 times daily); group 2, AmB (0.7-1 mg/kg) and fluconazole (800 mg daily); group 3, AmB (0.7-1 mg/kg) and fluconazole (600 mg twice daily); and group 4, AmB (0.7-1 mg/kg) and voriconazole (300 mg twice daily). The primary end point was the rate of clearance of infection from the cerebrospinal fluid (CSF) or early fungicidal activity (EFA), as determined by results of serial, quantitative CSF cryptococcal cultures. RESULTS There were no statistically significant differences in the rate of clearance of cryptococcal colony-forming units (CFU) in CSF samples among the 4 treatment groups; the mean (±standard deviation) EFA for treatment groups 1, 2, 3, and 4 were -0.41 ± 0.22 log CFU/mL CSF/day, -0.38 ± 0.18 log CFU/mL CSF/day, -0.41 ± 0.35 log CFU/mL CSF/day, and -0.44 ± 0.20 log CFU/mL CSF/day, respectively. Overall mortality was 12% (9 of 78 patients died) at 2 weeks and 29% (22 of 75 patients died) at 10 weeks, with no statistically significant differences among groups. There were few laboratory abnormalities related to the second agents given; in particular, there were no statistically significant (≥grade 3) increases in alanine transaminase level or decreases in neutrophil count. CONCLUSIONS There was no statistically significant difference in EFA between AmB in combination with fluconazole and AmB plus 5-FC for the treatment of HIV-associated cryptococcal meningitis. AmB plus fluconazole (800-1200 mg/day) represents an immediately implementable alternative to AmB plus 5-FC. AmB plus voriconazole is an effective alternative combination in patients not receiving interacting medications.

Cryptococcal meningitis: improving access to essential antifungal medicines in resource-poor countries

Cryptococcal meningitis is the leading cause of adult meningitis in sub-Saharan Africa, and contributes up to 20% of AIDS-related mortality in low-income and middle-income countries every year. Antifungal treatment for cryptococcal meningitis relies on three old, off-patent antifungal drugs: amphotericin B deoxycholate, flucytosine, and fluconazole. Widely accepted treatment guidelines recommend amphotericin B and flucytosine as first-line induction treatment for cryptococcal meningitis. However, flucytosine is unavailable in Africa and most of Asia, and safe amphotericin B administration requires patient hospitalisation and careful laboratory monitoring to identify and treat common side-effects. Therefore, fluconazole monotherapy is widely used in low-income and middle-income countries for induction therapy, but treatment is associated with significantly increased rates of mortality. We review the antifungal drugs used to treat cryptococcal meningitis with respect to clinical effectiveness and access issues specific to low-income and middle-income countries. Each drug poses unique access challenges: amphotericin B through cost, toxic effects, and insufficiently coordinated distribution; flucytosine through cost and scarcity of registration; and fluconazole through challenges in maintenance of local stocks--eg, sustainability of donations or insufficient generic supplies. We advocate ten steps that need to be taken to improve access to safe and effective antifungal therapy for cryptococcal meningitis.

High ongoing burden of cryptococcal disease in Africa despite antiretroviral roll out.

Cryptococcosis is now the commonest cause of adult meningitis in much of Southern and East Africa [1]. Despite currently available antifungal therapies, acute mortality ranges from 30 to over 50% in published series [2, 3]. The result is that cryptococcal infection accounts for 10-20 % of mortality in HIV-infected cohorts from Sub Saharan Africa [1], and recently published estimates by Park et al (AIDS 20th February 2009, issue 23, 525-30) place the overall toll at an estimated 504,000 deaths in sub-saharan Africa annually [4]. As part of an ongoing programme of work aimed at improving management of cryptococcal meningitis, we have prospectively monitored the number of new India Ink positive cases of cryptococcal meningitis diagnosed at GF Jooste Hospital, Cape Town, South Africa, for the last 6 years (2003-8). This is a public sector adult hospital serving a population of 1.3 million (including a large part of Khayelitsha township, population 500,000, with HIV antenatal seroprevalence of 32.7% in 2006 [5]). During this period, the area served by the hospital, and referral patterns for patients, have not changed. Antiretroviral therapy (ART) access has been substantially increased in the public sector clinics in the hospitals referral area from 660 adult patients on ART at the end of 2003 to 13,985 by the end of 2008, based on figures from the provincial reporting system described elsewhere [6]. It is estimated that 60% of adults with new World Health Organization (WHO) stage IV HIV disease in this setting are now accessing ART [6]. But despite this increase in the proportion of eligible patients receiving ART, the absolute number of patients with advanced disease not accessing treatment has remained constant or increased in recent years, due to the evolution of the epidemic [6]. This is in keeping with our finding that there has been no reduction in the number of new India Ink positive cases of cryptococcal meningitis presenting to our hospital over this period (Figure 1). Figure 1 Number of adult patients on anti-retroviral therapy (ART) in the hospital referral area, and the number of patients with India Ink positive cryptococcal meningitis presenting to the hospital by year, 2003-2008. There has been a major effort to expand access to ART throughout sub-Saharan Africa over recent years. However despite implementation of successful treatment programmes, in many settings the numbers of people progressing to advanced immunosuppression exceeds the capacity of ART programmes, and large numbers patients presenting to health services with advanced HIV and opportunistic infections die without accessing ART. The result is that the “treatment gap” is not narrowed, and AIDS-related illness such as cryptococcal meningitis and the associated mortality are not reduced. This is illustrated by the fact that, in the Western Cape Province, where GF Jooste hospital is located, the proportion of adult patients starting ART with CD4 counts below 50 cells/μl has fallen from 51.3% in 2001 to 21.5% in 2005 in line with increased access to care [6], while the absolute numbers of patients in this category has increased. Furthermore, unpublished aggregate data from the laboratory information system in the Province, further demonstrates that, irrespective of ART, the absolute numbers of all adult patients known to the health care system with CD4 counts below 100 cells/μl is increasing year-on-year (personal communication, Meg Osler, Provincial Government of Western Cape). As these large numbers of patients with low CD4 counts not yet accessing ART remain at high risk of opportunistic infection, the burden of cryptococcal meningitis is likely to continue undiminished in many areas, despite increasing access to ART. These data reinforce the urgent need to improve the acute management of cryptococcal meningitis, and to facilitate earlier diagnosis and treatment, especially now that access to ART offers the possibility of a good long term prognosis, provided patients survive the acute cryptococcal infection [7]. This needs to be specifically addressed as an integral part of the response to the HIV epidemic in Africa, along with earlier HIV diagnosis and access to ART.

Efficient phagocytosis and laccase activity affect the outcome of HIV-associated cryptococcosis

BACKGROUND Cryptococcal meningitis (CM) is a leading cause of HIV-associated mortality globally. High fungal burden in cerebrospinal fluid (CSF) at diagnosis and poor fungal clearance during treatment are recognized adverse prognostic markers; however, the underlying pathogenic factors that drive these clinical manifestations are incompletely understood. We profiled a large set of clinical isolates for established cryptococcal virulence traits to evaluate the contribution of C. neoformans phenotypic diversity to clinical presentation and outcome in human cryptococcosis. METHODS Sixty-five C. neoformans isolates from clinical trial patients with matched clinical data were assayed in vitro to determine murine macrophage uptake, intracellular proliferation rate (IPR), capsule induction, and laccase activity. Analysis of the correlation between prognostic clinical and host immune parameters and fungal phenotypes was performed using Spearmans r, while the fungal-dependent impact on long-term survival was determined by Cox regression analysis. RESULTS High levels of fungal uptake by macrophages in vitro, but not the IPR, were associated with CSF fungal burden (r = 0.38, P = 0.002) and long-term patient survival (hazard ratio [HR] 2.6, 95% CI 1.2-5.5, P = 0.012). High-uptake strains were hypocapsular (r = -0.28, P = 0.05) and exhibited enhanced laccase activity (r = 0.36, P = 0.003). Fungal isolates with greater laccase activity exhibited heightened survival ex vivo in purified CSF (r = 0.49, P < 0.0001) and resistance to clearance following patient antifungal treatment (r = 0.39, P = 0.003). CONCLUSION These findings underscore the contribution of cryptococcal-phagocyte interactions and laccase-dependent melanin pathways to human clinical presentation and outcome. Furthermore, characterization of fungal-specific pathways that drive clinical manifestation provide potential targets for the development of therapeutics and the management of CM. FUNDING This work was made possible by funding from the Wellcome Trust (WT088148MF), the Medical Research Council (MR/J008176/1), the NIHR Surgical Reconstruction and Microbiology Research Centre and the Lister Institute for Preventive Medicine (to R.C. May), and a Wellcome Trust Intermediate fellowship (089966, to T. Bicanic). The C. neoformans isolates were collected within clinical trials funded by the British Infection Society (fellowship to T. Bicanic), the Wellcome Trust (research training fellowships WT069991, to A.E. Brouwer and WT081794, to J.N. Jarvis), and the Medical Research Council, United Kingdom (76201). The funding sources had no role in the design or conduct of this study, nor in preparation of the manuscript.