Long-term outcome of AIDS-associated cryptococcosis in the era of combination antiretroviral therapy

Global guideline for the diagnosis and management of cryptococcosis: an initiative of the ECMM and ISHAM in cooperation with the ASM

Cryptococcosis is a major worldwide disseminated invasive fungal infection. Cryptococcosis, particularly in its most lethal manifestation of cryptococcal meningitis, accounts for substantial mortality and morbidity. The breadth of the clinical cryptococcosis syndromes, the different patient types at-risk and affected, and the vastly disparate resource settings where clinicians practice pose a complex array of challenges. Expert contributors from diverse regions of the world have collated data, reviewed the evidence, and provided insightful guideline recommendations for health practitioners across the globe. This guideline offers updated practical guidance and implementable recommendations on the clinical approaches, screening, diagnosis, management, and follow-up care of a patient with cryptococcosis and serves as a comprehensive synthesis of current evidence on cryptococcosis. This Review seeks to facilitate optimal clinical decision making on cryptococcosis and addresses the myriad of clinical complications by incorporating data from historical and contemporary clinical trials. This guideline is grounded on a set of core management principles, while acknowledging the practical challenges of antifungal access and resource limitations faced by many clinicians and patients. More than 70 societies internationally have endorsed the content, structure, evidence, recommendation, and pragmatic wisdom of this global cryptococcosis guideline to inform clinicians about the past, present, and future of care for a patient with cryptococcosis.

Cryptococcal meningitis

Cryptococcus neoformans and Cryptococcus gattii species complexes cause meningoencephalitis with high fatality rates and considerable morbidity, particularly in persons with deficient T cell-mediated immunity, most commonly affecting people living with HIV. Whereas the global incidence of HIV-associated cryptococcal meningitis (HIV-CM) has decreased over the past decade, cryptococcosis still accounts for one in five AIDS-related deaths globally due to the persistent burden of advanced HIV disease. Moreover, mortality remains high (~50%) in low-resource settings. The armamentarium to decrease cryptococcosis-associated mortality is expanding: cryptococcal antigen screening in the serum and pre-emptive azole therapy for cryptococcal antigenaemia are well established, whereas enhanced pre-emptive combination treatment regimens to improve survival of persons with cryptococcal antigenaemia are in clinical trials. Short courses (≤7 days) of amphotericin-based therapy combined with flucytosine are currently the preferred options for induction therapy of cryptococcal meningitis. Whether short-course induction regimens improve long-term morbidity such as depression, reduced neurocognitive performance and physical disability among survivors is the subject of further study. Here, we discuss underlying immunology, changing epidemiology, and updates on the management of cryptococcal meningitis with emphasis on HIV-associated disease.

Clinical Features of Cryptococcal Meningoencephalitis in HIV-Positive and -Negative Patients in a Resource-Limited Setting

Cryptococcal meningoencephalitis is a systemic fungal infection in immunocompromised and immunocompetent individuals. This study investigated the clinical characteristics and factors associated with mortality in HIV-associated and non-HIV-associated cryptococcal meningoencephalitis in a resource-limited setting. This was a retrospective cohort study of patients with cryptococcal meningoencephalitis between January 2009 and December 2019 at a tertiary teaching hospital in Thailand. Overall, 1019 patients with cryptococcal meningoencephalitis were enrolled, and 923 (90.6%) were HIV-positive. The patients with HIV-associated cryptococcal meningoencephalitis were younger than the HIV-negative patients (37 versus 56 years, p < 0.01). The HIV-negative patients were more likely to have underlying conditions (52.1% versus 7.5%; p < 0.01), had a longer median duration of headaches prior to admission (14 days versus 6 days, p < 0.01), and were more likely to have an altered mental status at presentation (36.5% versus 18.6%, p < 0.01) and pulmonary involvement (15.6% versus 0.8%, p < 0.01). The HIV-positive patients had lower cerebrospinal fluid (CSF) white blood cell counts (4 versus 94 cells/mm3; p < 0.01), lower CSF protein (69 versus 157 mg/dL; p < 0.01), higher CSF glucose (38.8 versus 21 mg/dL; p < 0.01), and more frequent cryptococcemia (44.1% versus 20.5%; p < 0.01). The mortality rate was high but not significantly different between the two groups (30.2% versus 33.2%; p = 0.53). The HIV-positive patients with comorbidities, fever, an altered mental status at presentation, a CSF white blood cell count below 20 cell/mm3, fungemia, and positive CSF India ink were independently associated with 30-day mortality. In comparison, an altered mental status at presentation and fungemia were associated with 30-day mortality in HIV-negative patients. In conclusion, HIV-negative patients with cryptococcal meningoencephalitis had more extensive central nervous system inflammation, although the two groups' mortality rates were similar. Unfavorable prognostic factors included comorbidities, fever, an altered mental status at presentation, a low CSF white blood cell count, fungemia, and positive CSF India ink.

Fluconazole Resistance and Virulence in In Vitro Induced-Fluconazole Resistant Strains and in Clinical Fluconazole Resistant Strain of Cryptococcus deuterogattii

Neuromeningeal cryptococcosis is a life-threatening infection of the central nervous system, caused by encapsulated yeast belonging to the Cryptococcus neoformans and Cryptococcus gattii species complexes. Recent data showed that virulence and antifungal resistance are variable for yeasts belonging to the C. gattii species complex. There is an increase in resistance to fluconazole for yeasts of the C. gattii species complex and the virulence is variable according to the genotype. In the present study, (i) we explored and compared the mechanisms of resistance to fluconazole between C. deuterogattii clinically resistant strains and induced fluconazole-resistant strains by exposure to fluconazole in vitro, and (ii) we studied their virulence in the Galleria mellonella study model. We demonstrated that the fluconazole resistance mechanisms involved were different between clinically resistant strains and induced resistant strains. We also demonstrated that fluconazole-induced resistant strains are less virulent when compared to the original susceptible strains. On the contrary, the clinically resistant strain tested maintains its virulence compared to fluconazole-susceptible strains of the same sequence type.

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.

High Burden of Cryptococcal Meningitis Among ART-Experienced HIV-infected Patients in Northern Uganda in the era of “Test and Treat”: Implications for Cryptococcal Screening Programs

Background

The impact of the “test and treat” program for human immunodeficiency virus (HIV) treatment in rural areas of Uganda on cryptococcal antigen (CrAg) screening or cryptococcal meningitis (CM) is poorly understood.

Methods

We retrospectively evaluated clinical factors in 212 HIV-infected patients diagnosed with CM from February of 2017 to November of 2019 at Lira Regional Referral Hospital in northern Uganda.

Results

Among 212 patients diagnosed with CM, 58.5% were male. Median age was 35 years; CD4 count and HIV viral load (VL) were 86 cells/μL and 9463 copies/mL, respectively. Only 10% of patients had a previous history of CM. We found that 190 of 209 (90.9%) patients were ART experienced and 19 (9.1%) were ART naive. Overall, 90 of 212 (42.5%) patients died while hospitalized (median time to death, 14 days). Increased risk of death was associated with altered mental status (hazard ratio [HR], 6.6 [95% confidence interval {CI}, 2.411–18.219]; P ≤ .0001) and seizures (HR, 5.23 [95% CI, 1.245–21.991]; P = .024).

Conclusions

Current guidelines recommend CrAg screening based on low CD4 counts for ART-naive patients and VL or clinical failure for ART-experienced patients. Using current guidelines for CrAg screening, some ART-experienced patients miss CrAg screening in resource-limited settings, when CD4 or VL tests are unavailable. We found that the majority of HIV-infected patients with CM were ART experienced (90.9%) at presentation. The high burden of CM in ART-experienced patients supports a need for improved CrAg screening of ART-exposed patients.

Cryptococcal meningoencephalitis: time for action

Cryptococcal meningoencephalitis was first described over a century ago. This fungal infection is preventable and treatable yet continues to be associated with excessive morbidity and mortality. The largest burden of disease resides in people living with HIV in low-income and middle-income countries. In this group, mortality with the best antifungal induction regimen (7 days of amphotericin B deoxycholate [1·0 mg/kg per day] and flucytosine [100·0 mg/kg per day]) in a clinical trial setting was 24% at 10 weeks. The world is now at an inflection point in terms of recognition, research, and action to address the burden of morbidity and mortality from cryptococcal meningoencephalitis. However, the scope of interventional programmes needs to increase, with particular attention to implementation science that is specific to individual countries. This Review summarises causes of excessive mortality, interventions with proven survival benefit, and gaps in knowledge and practice that contribute to the ongoing high death toll from cryptococcal meningoencephalitis. TRANSLATIONS: For the Vietnamese and Chichewa translations of the abstract see Supplementary Materials section.

MRI imaging features of HIV-related central nervous system diseases: diagnosis by pattern recognition in daily practice

With the advent of antiretroviral therapy (ART), the prognosis of people infected with human immunodeficiency virus (HIV) has improved, and the frequency of HIV-related central nervous system (CNS) diseases has decreased. Nevertheless, mortality from HIV-related CNS diseases, including those associated with ART (e.g., immune reconstitution inflammatory syndrome) remains significant. Magnetic resonance imaging (MRI) can improve the outlook for people with HIV through early diagnosis and prompt treatment. For example, HIV encephalopathy shows a diffuse bilateral pattern, whereas progressive multifocal leukoencephalopathy, HIV-related primary CNS lymphoma, and CNS toxoplasmosis show focal patterns on MRI. Among the other diseases caused by opportunistic infections, CNS cryptococcosis and CNS tuberculosis have extremely poor prognoses unless diagnosed early. Immune reconstitution inflammatory syndrome shows distinct MRI findings from the offending opportunistic infections. Although distinguishing between HIV-related CNS diseases based on imaging alone is difficult, in this review, we discuss how pattern recognition approaches can contribute to their early differentiation.

Cryptococcus neoformans infection in Human Immunodeficiency Virus (HIV)-infected and HIV-uninfected patients at an inner-city tertiary care hospital in the Bronx

Cryptococcus neoformans causes life-threatening meningoencephalitis. Human immunodeficiency virus (HIV) infection is the most significant predisposing condition, but persons with other immunodeficiency states as well as phenotypically normal persons develop cryptococcosis. We retrospectively reviewed medical records of all patients with a diagnosis of cryptococcosis between 2005 and 2017 at our inner-city medical center in the Bronx, an epicenter of AIDS in New York City, and analyzed demographic data, clinical manifestations, laboratory findings, treatment, and mortality for these patients. In sum, 63% of the cases over this 12-year period occurred in HIV-infected patients. And 61% of the HIV-infected patients were non-adherent with antiretroviral therapy, 10% were newly diagnosed with AIDS, and 4% had unmasking cryptococcus-associated immune reconstitution inflammatory syndrome. The majority were Hispanic or black in ethnicity/race. HIV-uninfected patients (47/126) were older (P < .0001), and the majority had an immunocompromising condition. They were less likely to have a headache (P = .0004) or fever (P = .03), had prolonged time to diagnosis (P = .04), higher cerebrospinal fluid (CSF) glucose levels (P = .001), less CSF culture positivity (P = .03), and a higher 30-day mortality (P = .03). Cases in HIV-uninfected patients were often unsuspected during their initial evaluation, leading to a delay in infectious diseases consultation, which was associated with mortality (P = .03). Our study indicates that HIV infection remains the most important predisposing factor for cryptococcosis despite availability of antiretroviral therapy and highlights potential missed opportunities for earlier diagnosis and differences in clinical and prognostic factors between HIV-infected and HIV-uninfected patients.

Interactions of FK506 and Rapamycin With FK506 Binding Protein 12 in Opportunistic Human Fungal Pathogens

Over the past few decades advances in modern medicine have resulted in a global increase in the prevalence of fungal infections. Particularly people undergoing organ transplants or cancer treatments with a compromised immune system are at an elevated risk for lethal fungal infections such as invasive candidiasis, aspergillosis, cryptococcosis, etc. The emergence of drug resistance in fungal pathogens poses a serious threat to mankind and it is critical to identify new targets for the development of antifungals. Calcineurin and TOR proteins are conserved across eukaryotes including pathogenic fungi. Two small molecules FK506 and rapamycin bind to FKBP12 immunophilin and the resulting complexes (FK506-FKBP12 and rapamycin-FKBP12) target calcineurin and TOR, respectively in both humans and fungi. However, due to their immunosuppressive nature these drugs in the current form cannot be used as an antifungal. To overcome this, it is important to identify key differences between human and fungal FKBP12, calcineurin, and TOR proteins which will facilitate the development of new small molecules with higher affinity toward fungal components. The current review highlights FK506/rapamycin-FKBP12 interactions with calcineurin/TOR kinase in human and fungi, and development of non-immunosuppressive analogs of FK506, rapamycin, and novel small molecules in inhibition of fungal calcineurin and TOR kinase.

Opportunistic Cryptococcal Antigenemia in the HAART Era at HIV Epidemic Settings of Northwest Ethiopia

Background

Cryptococcus neoformans is a frequent opportunistic infection in patients with the acquired immunodeficiency syndrome. While the advent of ART reduces the occurrence of cryptococcal meningitis in HIV patients, cryptococcal disease remains a leading cause of morbidity and mortality in the developing world especially in sub-Saharan Africa which is the epicenter of HIV. This study aimed to assess the cryptococcal antigenemia, CD4+ Th cell counts, HIV RNA viral load, and clinical presentations among HIV-positive patients in Northwest Ethiopia.

Method

A total of two hundred (200) HIV-positive patients were recruited for this study. Cryptococcus antigenemia prevalence in plasma samples of HIV‐positive patients was determined by using Antigen lateral flow assay (CrAg‐LFA) also, and CD4+ Th cell counts and HIV‐RNA levels were quantified from blood specimen. Patients' demographic data, clinical manifestation, and concurrent opportunistic infection were recorded.

Result

The sex distributions of study participants were 105(52.5%) male and 94(47.5%) female with an age range of 15–65 (mean 39.42 ± 9) years. All patients had a CD4+ T-cell count <100 cells/µl with the median 54 cells/μl and median HIV-RNA viral load 2.16 × 10⁵ RNA copies/ml (50–3.66 × 10⁵ RNA copies/ml); the prevalence of cryptococcal antigenemia was found to be 4% in HIV-positive patients. More than half and two third of CrAg‐positive patients had a CD4 count <25 cells/μl and HIV viral load >10,000 copies/ml, respectively, as well; Tuberculosis, Candidiasis, and herpes zoster are the most often observed concurrent infections while cryptococcal antigenemia is significantly associated with oral candidiasis (p < 0.001).

Conclusion

Although the advent of ART, early diagnosis of cryptococcosis, and application of antifungal interventions, HIV-induced cryptococcal antigenemia positivity in HIV infected individuals is still the countries' big challenge. Thus, stringent follow-up and case management should be considered.

Targeted therapies for autoimmune/idiopathic nonmalignant diseases: risk and management of opportunistic infections

INTRODUCTION

The management of patients affected by autoimmune/idiopathic diseases has been revolutionized by the development of targeted therapies (TT). However, the use of TT is complicated by several adverse events, like opportunistic infections (OIs). The potential of TT to predispose to OIs mainly depends on the site of action; nevertheless, such associations are far from being deterministic, because many factors could increase the infection risk.

AREAS COVERED

The impact on the infective risk of different TT used for autoimmune/idiopathic diseases is far from being completely understood. Indeed, many post-marketing reports documented severe or unexpected infections in patients treated with TT that did not emerge during registrative trials. In this review, the authors attempt to provide an easy and practical update about the 'infectious' safety of TT and examine the management strategies of OIs and other infections more frequently observed in the course of treatment with TT.

EXPERT OPINION

The authors suggest to precisely schedule the clinical management of these subjects, both to prevent and eventually treat promptly the TT-related infectious complications. A coordinated approach should be implemented from different medical specialties to improve the overall understanding of safety of TT and, in general, the management of opportunistic infections in immune-compromised hosts.

Mortality After Cryptococcal Infection in the Modern Antiretroviral Therapy Era

BACKGROUND

The prevalence of cryptococcosis in people living with HIV (PLWH) in the developed world has decreased considerably in the modern antiretroviral therapy (ART) era. Although early mortality of PLWH with opportunistic infections is well understood, overall mortality has not been previously evaluated.

METHODS

We conducted a retrospective cohort study of cryptococcosis in PLWH from January 1, 2002, to July 1, 2017. Data were also evaluated before and after 2008 to evaluate the possible effect of modern ART on outcomes. Death date was obtained from the hospital's medical informatics database and the Social Security Death Index. Participants were grouped as survivors, early-mortality (death <90 days), and late-mortality (death ≥90 days) individuals.

RESULTS

We reviewed 105 PLWH with cryptococcosis, with 55 survivors (52.4%), 17 early-mortality (16.2%), and 33 late-mortality individuals (31.4%). Overall, mortality was 47.6% (n = 50) with a median follow-up of 3.7 years (interquartile range 1.1, 8.1 years). Late-mortality individuals were less likely to be virally suppressed at the last observation compared with survivors (24% vs 62%, P < 0.001). Individuals diagnosed in the modern ART era had significantly lower mortality (hazard ratio 0.5, confidence interval: 0.2 to 0.8) and were more likely to be virally suppressed at the last observation (57% vs 29%, P = 0.003). Individuals with government-provided insurance had a higher mortality compared to those with private insurance (hazard ratio 2.8, confidence interval: 1.1 to 7.2, P = 0.013).

CONCLUSIONS

Despite improvements in ART, PLWH have high mortality after cryptococcal infection that persists beyond their initial hospitalization. Lower mortality was associated with increased HIV viral suppression and private insurance in the modern ART era.

New Triazole NT-a9 Has Potent Antifungal Efficacy against Cryptococcus neoformans In Vitro and In Vivo

In the past decades, the incidence of cryptococcosis has increased dramatically, which poses a new threat to human health. However, only a few drugs are available for the treatment of cryptococcosis. Here, we described a leading compound, NT-a9, an analogue of isavuconazole, that showed strong antifungal activities in vitro and in vivo NT-a9 showed a wide range of activities against several pathogenic fungi in vitro, including Cryptococcus neoformans, Cryptococcus gattii, Candida albicans, Candida krusei, Candida tropicalis, Candida glabrata, and Candida parapsilosis, with MICs ranging from 0.002 to 1 μg/ml. In particular, NT-a9 exhibited excellent efficacy against C. neoformans, with a MIC as low as 0.002 μg/ml. NT-a9 treatment resulted in changes in the sterol contents in C. neoformans, similarly to fluconazole. In addition, NT-a9 possessed relatively low cytotoxicity and a high selectivity index. The in vivo efficacy of NT-a9 was assessed using a murine disseminated-cryptococcosis model. Mice were infected intravenously with 1.8 × 10⁶ CFU of C. neoformans strain H99. In the survival study, NT-a9 significantly prolonged the survival times of mice compared with the survival times of the control group or the isavuconazole-, fluconazole-, or amphotericin B-treated groups. Of note, 4 and 8 mg/kg of body weight of NT-a9 rescued all the mice, with a survival rate of 100%. In the fungal-burden study, NT-a9 also significantly reduced the fungal burdens in brains and lungs, while fluconazole and amphotericin B only reduced the fungal burden in lungs. Taken together, these data suggested that NT-a9 is a promising antifungal candidate for the treatment of cryptococcosis infection.

Disseminated cryptococcal infection in a patient with treatment-naïve chronic lymphocytic leukemia (CLL)

We report a case of disseminated cryptococcosis in a treatment-naïve chronic lymphocytic leukemia (CLL) patient. A 60-year-old man presented with a two-week history of intermittent fevers, frontal headaches, night sweats, weight loss and multiple pink papules on hands and face. Cryptococcemia was found by blood culture unexpectedly. Further investigation confirmed cryptococcal meningitis and skin disease. He responded to two week amphotericin B and flucytosine followed by four-week amphotericin B and fluconazole, three-month high dose fluconazole (800 mg/day), and maintenance fluconazole (400 mg/day) thereafter. CSF pleocytosis persisted until day 203 while cryptococcal antigen in the CSF persisted at day 334 of treatment.

Cryptococcal meningitis after ART: Need for proper baseline evaluation in the era of 'Test & Treat'

Cryptococcal meningitis (CM) contributes significantly to high early mortality in the setting of advanced HIV. In resource poor settings, the current HIV disease management approach is focused on commencing antiretroviral therapy (ART) on the same day of HIV diagnosis (‘Test and Treat’). The HIV program in Nigeria does not currently provide CrAg screening for patients with newly diagnosed and advanced HIV disease. We report a case of severe cryptococcal meningitis presenting following the commencement of ART. There is clear benefit in the early commencement of ART among HIV infected patients and to prevent patients lost to follow-up as aimed with the ‘Test & Treat’ approach. However, this approach needs to be balanced against the risk of IRIS and its associated morbidity and mortality when those patients are not being properly evaluated for opportunistic infections being present without overt symptoms.

In Vivo Efficacy of VT-1129 against Experimental Cryptococcal Meningitis with the Use of a Loading Dose-Maintenance Dose Administration Strategy

VT-1129 is a novel fungal enzyme-specific Cyp51 inhibitor with potent cryptococcal activity. Because of its long half-life (>6 days in mice) and our desire to quickly reach potent efficacy, we evaluated a VT-1129 loading dose-maintenance dose strategy against cryptococcal meningitis. VT-1129 plasma and brain pharmacokinetics were first studied in healthy mice, and these data were used to model loading dose-maintenance dose regimens to generate different steady-state concentrations. Mice were inoculated intracranially with Cryptococcus neoformans, and oral treatment began 1 day later. Treatment consisted of placebo or one of three VT-1129 loading dose-maintenance dose regimens, i.e., loading dose of 1, 3, or 30 mg/kg on day 1, followed by once-daily maintenance doses of 0.15, 0.5, or 5 mg/kg, respectively. In the fungal burden arm, therapy continued for 14 days and brains were collected on day 15 for fungal burden assessments. In the survival arm, treatment continued for 10 days, after which mice were monitored without therapy until day 30. VT-1129 plasma and brain concentrations were also measured. All VT-1129 doses significantly improved survival and reduced fungal burdens, compared to placebo. VT-1129 plasma and brain levels correlated with fungal burden reductions (R2 = 0.72 and R2 = 0.67, respectively), with a plasma concentration of 1 μg/ml yielding a reduction of ∼5 log10 CFU/g. With the highest loading dose-maintenance dose regimen, fungal burdens were undetectable in one-half of the mice in the fungal burden arm and in one-fourth of the mice in the survival arm, 20 days after the final dose. These data support a loading dose-maintenance dose strategy for quickly reaching highly efficacious VT-1129 concentrations for treating cryptococcal meningitis.

The Fungal Cyp51 Inhibitor VT-1129 Is Efficacious in an Experimental Model of Cryptococcal Meningitis

Cryptococcal meningitis is a significant cause of morbidity and mortality in immunocompromised patients. VT-1129 is a novel fungus-specific Cyp51 inhibitor with potent in vitro activity against Cryptococcus species. Our objective was to evaluate the in vivo efficacy of VT-1129 against cryptococcal meningitis. Mice were inoculated intracranially with Cryptococcus neoformans Oral treatment with VT-1129, fluconazole, or placebo began 1 day later and continued for either 7 or 14 days, and brains and plasma were collected on day 8 or 15, 1 day after therapy ended, and the fungal burden was assessed. In the survival study, treatment continued until day 10 or day 28, after which mice were monitored off therapy until day 30 or day 60, respectively, to assess survival. The fungal burden was also assessed in the survival arm. VT-1129 plasma and brain concentrations were also measured. VT-1129 reached a significant maximal survival benefit (100%) at a dose of 20 mg/kg of body weight once daily. VT-1129 at doses of ≥0.3 mg/kg/day and each dose of fluconazole significantly reduced the brain tissue fungal burden compared to that in the control after both 7 and 14 days of dosing. The fungal burden was also undetectable in most mice treated with a dose of ≥3 mg/kg/day, even ≥20 days after dosing had stopped, in the survival arm. In contrast, rebounds in fungal burden were observed with fluconazole. These results are consistent with the VT-1129 concentrations, which remained elevated long after dosing had stopped. These data demonstrate the potential utility of VT-1129 to have a marked impact in the treatment of cryptococcal meningitis.

Cryptococcal Meningitis: A Retrospective Cohort of a Brazilian Reference Hospital in the Post-HAART Era of Universal Access

Objective

Cryptococcus neoformans is a common opportunistic infection in adults with acquired immunodeficiency syndrome worldwide. However, limited data exist for HIV-infected patients in the post-HAART (highly active antiretroviral therapy) era in Brazil. The aim of this study was to describe the clinical characteristics and outcomes of cryptococcosis in a cohort of patients attending a teaching tertiary care hospital in southern Brazil after the introduction of HAART in Brazil.

Patients and Methods

A retrospective study was conducted in tertiary care hospital in southern Brazil. Detailed data on risk factors, clinical manifestations, diagnosis methods, treatment, and prognosis of patients with meningeal cryptococcosis were evaluated from January 2009 to December 2016.

Results

Seventy-nine cases of cryptococcal meningitis were identified. Most of the patients presented positive CSF (cerebrospinal fluid) cultures for Cryptococcus neoformans (96%). The prevalence of males and females with meningeal cryptococcosis was similar. The age of the patients ranged from 5 to 67 years. The median time of hospitalization was 28 days. The most common underlying disease was HIV (82%), followed by solid transplant (10%). Fever, nausea, vomiting, headache, and altered mental status were the most common clinical manifestations. Initial opening intracranial pressures varied from 30 to 130 cm H₂O. CNS imaging abnormalities include hydrocephalus and hypodensities. Widened Virchow–Robin spaces were described in only 2 patients (2.5%). Induction treatment of the majority of the patients consisted of amphotericin B and flucytosine (67%) followed by amphotericin B and fluconazole (19%). Multivariate analysis of Cox regression identified headache at presentation, mechanical ventilation, CSF glucose <20 mg/dL, and CSF cryptococcal antigen ≥1 : 1000 for independent risk factors for death. All-cause 30-day and 60-day mortalities were 19% and 24%, respectively.

Conclusions

Meningeal cryptococcosis mostly caused by C. neoformans continues to occur predominantly in HIV-infected adults despite HAART being widely distributed in Brazil. Cryptococcosis remains a significant opportunistic infection in solid organ transplant recipients. Despite adequate antifungal treatment and management of intracranial hypertension in a reference tertiary care hospital, mortality was high. Identification of risk factors and additional treatment modalities, especially for intracranial hypertension, are necessary to improve care for patients with cryptococcal meningitis.

Detrimental Outcomes of Unmasking Cryptococcal Meningitis With Recent ART Initiation

BACKGROUND

Increased antiretroviral therapy (ART) availability has been associated with more patients developing cryptococcosis after ART initiation. Despite this changing epidemiology, data regarding cryptococcal meningitis in those already receiving ART are limited. We compared clinical presentations and outcomes among ART-naïve and ART-experienced Ugandans.

METHODS

We prospectively enrolled 605 HIV-infected persons with first-episode cryptococcal meningitis from August 2013 to May 2017 who received amphotericin-based combination therapy. We classified participants by ART status and ART duration and compared groups for 2-week survival.

RESULTS

Overall, 46% (281/605) of participants were receiving ART at presentation. Compared with those not receiving ART, those receiving ART had higher CD4 counts (P < .001) and lower cerebrospinal fluid fungal burdens (P < .001). Of those receiving ART, 56% (156/281) initiated ART within 6 months, and 18% (51/281) initiated ART within 14 days. Two-week mortality did not differ by ART status (27% in both ART-naïve and ART-experienced%; P > .99). However, 47% (24/51) of those receiving ART for ≤14 days died within 2 weeks, compared with 19% (20/105) of those receiving ART for 15-182 days and 26% (32/125) of those receiving ART for >6 months (P < .001). Among persons receiving ART for >6 months, 87% had HIV viral loads >1000 copies/mL.

CONCLUSIONS

Cryptococcosis after ART initiation is common in Africa. Patients initiating ART who unmask cryptococcal meningitis are at a high risk of death. Immune recovery in the setting of central nervous system infection is detrimental, and management of this population requires further study. Implementing pre-ART cryptococcal antigen screening is urgently needed to prevent cryptococcal meningitis after ART initiation.

Mechanisms of Pulmonary Escape and Dissemination by Cryptococcus neoformans

Cryptococcus neoformans is a common environmental saprophyte and human fungal pathogen that primarily causes disease in immunocompromised individuals. Similar to many environmentally acquired human fungal pathogens, C. neoformans initiates infection in the lungs. However, the main driver of mortality is invasive cryptococcosis leading to fungal meningitis. After C. neoformans gains a foothold in the lungs, a critical early step in invasion is transversal of the respiratory epithelium. In this review, we summarize current knowledge relating to pulmonary escape. We focus on fungal factors that allow C. neoformans to disseminate from the lungs via intracellular and extracellular routes.

Cryptococcal disease in the solid organ transplant setting: review of clinical aspects with a discussion of asymptomatic cryptococcal antigenemia

PURPOSE OF REVIEW

Cryptococcal infections are an important cause of morbidity and mortality in solid organ transplant patients. Here, we review the microbiology, epidemiology, clinical course, treatment, and outcomes of Cryptococcus in solid organ transplant recipients.

RECENT FINDINGS

We identify the unique findings in solid organ transplant patients when compared to other immunocompromised patients such as those with HIV. We also describe our experience and outcomes with regard to solid organ transplant patients who do not have positive fungal cultures, but cryptococcal antigen positivity and concern for cryptococcal disease.

SUMMARY

Our review will highlight the importance of these new diagnostic techniques in those with Cryptococcus and solid organ transplant, which will be the subject of new research.

HIV-Associated Cryptococcal Disease in Resource-Limited Settings: A Case for "Prevention Is Better Than Cure"?

Cryptococcal disease remains a significant source of global morbidity and mortality for people living with HIV, especially in resource-limited settings. The recently updated estimate of cryptococcal disease revealed a global incidence of 223,100 cases annually with 73% of these cases being diagnosed in sub-Saharan Africa. Furthermore, 75% of the estimated 181,100 deaths associated with cryptococcal disease occur in sub-Saharan Africa. Point-of-care diagnostic assays have revolutionised the diagnosis of this deadly opportunistic infection. The theory of asymptomatic cryptococcal antigenaemia as a forerunner to symptomatic meningitis and death has been conclusively proven. Thus, cryptococcal antigenaemia screening coupled with pre-emptive antifungal therapy has been demonstrated as a cost-effective strategy with survival benefits and has been incorporated into HIV national guidelines in several countries. However, this is yet to be implemented in a number of other high HIV burden countries. Flucytosine-based combination therapy during the induction phase is associated with improved survival, faster cerebrospinal fluid sterilisation and fewer relapses. Flucytosine, however, is unavailable in many parts of the world. Studies are ongoing on the efficacy of shorter regimens of amphotericin B. Early diagnosis, proactive antifungal therapy with concurrent management of raised intracranial pressure creates the potential to markedly reduce mortality associated with this disease.

Capsule Enlargement in Cryptococcus neoformans Is Dependent on Mitochondrial Activity

Cryptococcus neoformans is an environmental encapsulated yeast that behaves as an opportunistic pathogen in immunocompromised individuals. The capsule is the main virulence factor of this pathogen. This structure is highly dynamic, and it can change its size and structure according to the environmental conditions. During infection, C. neoformans significantly enlarges the size of the capsule by the addition of new polysaccharide. It is believed that capsule growth is an energy-cost process, but this aspect has never been addressed. In this work, we have evaluated the role of mitochondrial activity on capsule growth using specific inhibitors of the electron respiratory chain. We observed that capsule growth was impaired in the presence of inhibitors of the respiratory chain as salicylhydroxamic acid or antimycin A. Furthermore, capsule growth correlated with an increase of the mitochondrial membrane potential and higher production of reactive oxygen species. Our results confirm that capsule growth depends on mitochondrial activity, and open new insights to understand the regulation of this process.

Incidence, clinical presentation, and outcome of HIV-1-associated cryptococcal meningitis during the highly active antiretroviral therapy era: a nationwide cohort study

BACKGROUND

Human immunodeficiency virus (HIV) infection with advanced immunosuppression predisposes to cryptococcal meningitis (CM). We describe the incidence, clinical presentation, and outcome of CM in HIV-infected individuals during the highly active antiretroviral therapy (HAART) era.

METHODS

A nationwide, population-based cohort of HIV-infected individuals was used to estimate incidence and mortality of CM including risk factors. A description of neurological symptoms of CM at presentation and follow-up in the study period 1995-2014 was included in this study.

RESULTS

Among 6,351 HIV-infected individuals, 40 were diagnosed with CM. The incidence rates were 3.7, 1.8, and 0.3 per 1000 person-years at risk in 1995-1996, 1997-1999, and 2000-2014, respectively. Initiation of HAART was associated with decreased risk of acquiring CM [incidence rate ratio (IRR), 0.1 (95% CI, 0.05-0.22)]. African origin was associated with increased risk of CM [IRR, 2.05 (95% CI, 1.00-4.20)]. The main signs and symptoms at presentation were headache, cognitive deficits, fever, neck stiffness, nausea, and vomiting. All individuals diagnosed with CM had a CD4⁺ cell count <200 cells/µl [median 26; interquartile range (IQR), 10-50)]. Overall, mortality following CM was high and mortality in the first 4 months has not changed substantially over time. However, individuals who survived generally had a favorable prognosis, with 86% (18/21) returning to the pre-CM level of activity.

CONCLUSION

The incidence of HIV-associated CM has decreased substantially after the introduction of HAART. To further decrease CM incidence and associated mortality, early HIV diagnosis and HAART initiation seems crucial.

Yeasts

Yeasts are unicellular organisms that reproduce mostly by budding and less often by fission. Most medically important yeasts originate from Ascomycota or Basidiomycota. Here, we review taxonomy, epidemiology, disease spectrum, antifungal drug susceptibility patterns of medically important yeast, laboratory diagnosis, and diagnostic strategies.

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.

Recent advances in AIDS-related cryptococcal meningitis treatment with an emphasis on resource limited settings

INTRODUCTION

Recent advances in the treatment and prevention of cryptococcal meningitis have the potential to decrease AIDS-related deaths. Areas covered: Targeted screening for asymptomatic cryptococcal antigenemia in persons with AIDS is a cost effective method for reducing early mortality in patients on antiretroviral therapy. For persons with symptomatic cryptococcal meningitis, optimal initial management with amphotericin and flucytosine improves survival compared to alternative therapies; however, amphotsericin is difficult to administer and flucytosine has not been available in middle or low income countries, where cryptococcal meningitis is most prevalent. Expert commentary: Improved care for cryptococcal meningitis patients in resource-limited settings is possible, and new treatment possibilities are emerging.

Integrated therapy for HIV and cryptococcosis

Cryptococcosis has been one of the most common opportunistic infections and causes of mortality among HIV-infected patients, especially in resource-limited countries. Cryptococcal meningitis is the most common form of cryptococcosis. Laboratory diagnosis of cryptococcosis includes direct microscopic examination, isolation of Cryptococcus from a clinical specimen, and detection of cryptococcal antigen. Without appropriate treatment, cryptococcosis is fatal. Early diagnosis and treatment is the key to treatment success. Treatment of cryptococcosis consists of three main aspects: antifungal therapy, intracranial pressure management for cryptococcal meningitis, and restoration of immune function with antiretroviral therapy (ART). Optimal integration of these three aspects is crucial to achieving successful treatment and reducing the mortality. Antifungal therapy consists of three phases: induction, consolidation, and maintenance. A combination of two drugs, i.e. amphotericin B plus flucytosine or fluconazole, is preferred in the induction phase. Fluconazole monotherapy is recommended during consolidation and maintenance phases. In cryptococcal meningitis, intracranial pressure rises along with CSF fungal burden and is associated with morbidity and mortality. Aggressive control of intracranial pressure should be done. Management options include therapeutic lumbar puncture, lumbar drain insertion, ventriculostomy, or ventriculoperitoneal shunt. Medical treatment such as corticosteroids, mannitol, and acetazolamide are ineffective and should not be used. ART has proven to have a great impact on survival rates among HIV-infected patients with cryptococcosis. The time to start ART in HIV-infected patients with cryptococcosis has to be deferred until 5 weeks after the start of antifungal therapy. In general, any effective ART regimen is acceptable. Potential drug interactions between antiretroviral agents and amphotericin B, flucytosine, and fluconazole are minimal. Of most potential clinical relevance is the concomitant use of fluconazole and nevirapine. Concomitant use of these two drugs should be cautious, and patients should be monitored closely for nevirapine-associated adverse events, including hepatotoxicity. Overlapping toxicities of antifungal and antiretroviral drugs and immune reconstitution inflammatory syndrome are not uncommon. Early recognition and appropriate management of these consequences can reinforce the successful integrated therapy in HIV-infected patients with cryptococcosis.

Siderophores; iron scavengers: the novel & promising targets for pathogen specific antifungal therapy

INTRODUCTION

The recent emergence of resistance, toxicity paradigm and limited efficacy of conventional antifungal drugs necessitate the identification of de novo targets in fungal metabolism. One of the most critical physiological processes during in vivo pathogenesis is maintenance of iron homeostasis. The most life threatening opportunistic human fungal pathogens like Aspergillus, Candida and Cryptococcus exploit the siderophore mediated iron uptake mechanism either for survival, virulence, propagation or resistance to oxidative stress envisaged in vivo during infection. Areas covered: In this review, we will highlight the metabolic pathways; specifically siderophore biosynthesis, uptake and utilisation, triggered in the fungal pathogens in iron starving conditions and the various putative targets viable in these pathways to be recruited as novel therapeutic antidotes either via biosynthetic enzymes catalytic site inhibitors or as drug conjugates through trojan horse approach and further role in the development of fungal specific reliable diagnostic markers. Expert opinion: Siderophores are the weapons released by a pathogen to conquer the battle for iron acquisition. Hence, the fungal siderophore biosynthetic pathways along with their uptake and utilisation mechanisms represent an ideal target for pathogen specific, host friendly therapeutic strategy which would block the proliferation of parasite without causing any harm to the mammalian host.

Burden of serious fungal infections in Tanzania

The incidence and prevalence of fungal infections in Tanzania remains unknown. We assessed the annual burden in the general population and among populations at risk. Data were extracted from 2012 reports of the Tanzanian AIDS program, WHO, reports, Tanzanian census, and from a comprehensive PubMed search. We used modelling and HIV data to estimate the burdens of Pneumocystis jirovecii pneumonia (PCP), cryptococcal meningitis (CM) and candidiasis. Asthma, chronic obstructive pulmonary disease and tuberculosis data were used to estimate the burden of allergic bronchopulmonary aspergillosis (ABPA) and chronic pulmonary aspergillosis (CPA). Burdens of candidaemia and Candida peritonitis were derived from critical care and/or cancer patients' data. In 2012, Tanzania's population was 43.6 million (mainland) with 1,500,000 people reported to be HIV-infected. Estimated burden of fungal infections was: 4412 CM, 9600 PCP, 81,051 and 88,509 oral and oesophageal candidiasis cases respectively. There were 10,437 estimated post-tuberculosis CPA cases, whereas candidaemia and Candida peritonitis cases were 2181 and 327 respectively. No reliable data exist on blastomycosis, mucormycosis or fungal keratitis. Over 3% of Tanzanians suffer from serious fungal infections annually, mostly related to HIV. Cryptococcosis and PCP are major causes of mycoses-related deaths. National surveillance of fungal infections is urgently needed.

The Investigational Drug VT-1129 Is a Highly Potent Inhibitor of Cryptococcus Species CYP51 but Only Weakly Inhibits the Human Enzyme

Cryptococcosis is a life-threatening disease often associated with HIV infection. Three Cryptococcus species CYP51 enzymes were purified and catalyzed the 14α-demethylation of lanosterol, eburicol, and obtusifoliol. The investigational agent VT-1129 bound tightly to all three CYP51 proteins (dissociation constant [Kd] range, 14 to 25 nM) with affinities similar to those of fluconazole, voriconazole, itraconazole, clotrimazole, and ketoconazole (Kd range, 4 to 52 nM), whereas VT-1129 bound weakly to human CYP51 (Kd, 4.53 μM). VT-1129 was as effective as conventional triazole antifungal drugs at inhibiting cryptococcal CYP51 activity (50% inhibitory concentration [IC50] range, 0.14 to 0.20 μM), while it only weakly inhibited human CYP51 activity (IC50, ∼600 μM). Furthermore, VT-1129 weakly inhibited human CYP2C9, CYP2C19, and CYP3A4, suggesting a low drug-drug interaction potential. Finally, the cellular mode of action for VT-1129 was confirmed to be CYP51 inhibition, resulting in the depletion of ergosterol and ergosta-7-enol and the accumulation of eburicol, obtusifolione, and lanosterol/obtusifoliol in the cell membranes.

Cryptococcosis in Acquired Immunodeficiency Syndrome Patients Clinically Confirmed and/or Diagnosed at Necropsy in a Teaching Hospital in Brazil

Cryptococcosis occurs in acquired immunodeficiency syndrome (AIDS) patients with poor compliance to antiretroviral therapy or unaware of their human immunodeficiency virus status who present severe immunosuppression at admission. Consequently, high mortality rates are observed due to disseminated fungal infection. This report presents clinical and postmortem data of AIDS patients with cryptococcosis in a teaching hospital in Brazil. Retrospectively, medical and necropsy records of AIDS patients with cryptococcosis clinically confirmed and/or postmortem verified were reviewed. Clinical data were compared with those of patients presenting a good outcome to evaluate disseminated fungal infection and the agreement between clinical and postmortem diagnosis. At admission, most of the 45 patients with cryptococcal meningitis who died, presented more altered consciousness (P = 0.0047), intracranial increased pressure (P = 0.047), and severe malnutrition (P = 0.0006) than the survivors. Of 29 (64.4%) patients with cryptococcal meningitis, 23 died before week 2 on antifungal therapy, and the other six during the next 3 months. The remaining 16 (35.6%) cases had other diagnoses and died soon after. At necropsy, 31 (68.9%) presented disseminated infection involving two or more organs, whereas 14 (31.1%) cases had meningeal or pulmonary localized infection. The agreement of 64.4% between clinical and postmortem diagnosis was similar to some studies. However, other reports have shown figures ranging from 34% to 95%. Currently, a progressive worldwide decrease of autopsies is worrying because the role of postmortem examination is pivotal to verify or identify the death causes, which contributes to improve the quality of clinical diagnosis and medical training.

Significant publications on infectious diseases pharmacotherapy in 2014

PURPOSE

The most important articles on infectious diseases (ID) pharmacotherapy published in the peer-reviewed literature in 2014, as nominated and selected by panels of pharmacists and others with ID expertise, are summarized.

SUMMARY

Members of the Houston Infectious Diseases Network were asked to nominate articles published in 2014 from prominent peer-reviewed journals that were felt to have a major impact in the field of ID pharmacotherapy. A list of 19 nominated articles on general ID-related topics and 9 articles specifically related to human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS) was compiled. In a national online survey, members of the Society of Infectious Diseases Pharmacists (SIDP) were asked to select from the list 10 general ID articles believed to have made a significant contribution to the field of ID pharmacotherapy and 1 article contributing to HIV/AIDS pharmacotherapy. Of the 291 SIDP members surveyed, 134 (46%) and 56 (19%) participated in the selection of general ID-related articles and HIV/AIDS-related articles, respectively. The 11 highest-ranked papers (10 general ID-related articles, 1 HIV/AIDS-related article) are summarized here.

CONCLUSION

With the vast number of articles published each year, it is difficult to remain up-to-date on current, significant ID pharmacotherapy publications. This review of significant publications in 2014 may be helpful by lessening this burden.

Favorable Evolution of Cryptococcal Meningitis in the Context of Flucytosine Resistance

Cryptococcal meningitis is a critical illness affecting 0.2% to 5% solid-organ transplant recipients with a 40% to 50% mortality. We report the case of a 48-year-old lung transplant recipient, who, 15 months after a right lung graft, kept parakeets and developed meningitis due to Cryptococcus neoformans. Immunosuppressive treatment was based on a quadruple sequential immunosuppressive therapy that included induction therapy with thymoglobulin, followed by corticosteroids, calcineurin inhibitors, and mycophenolate mofetil. Antifungal susceptibility testing of Cryptococcus neoformans showed resistance to flucytosine and intermediate sensitivity to fluconazole. Initial treatment adhered to international guidelines; however, the patient could not tolerate an effective double-antifungal therapy during the first 2 months of treatment. Despite this delayed treatment for an aggressive infection in an immunocompromised patient, the patient survived without relapse and received maintenance treatment with fluconazole during the course of 3 years. Administration of calcineurin inhibitors as immunosuppressive treatment may partly explain this outcome, as this therapeutic class is known to protect from severe forms of cryptococcal meningitis.

[Cryptococcal meningoencephalitis. Epidemiology and mortality risk factors in pre- and post-HAART era]

INTRODUCTION AND OBJECTIVE

Cryptococcal meningoencephalitis (CM) is an uncommon entity, but remains a major cause of morbidity and mortality in patients with AIDS.

MATERIAL AND METHODS

Review of CM cases in a university hospital. The diagnosis was determined by isolation of Cryptococcus neoformans in cerebrospinal fluid. Morbidity and mortality was assessed at 12 weeks (early mortality) and between 3 and 18 months after diagnosis (late mortality).

RESULTS

We analyzed 32 patients from 2,269 AIDS cases (1.41%). 10 patients between 1990-1996 and 22 between 1997-2014. Cryptococcal antigen in CSF was positive in all cases, with titers>1,024 in 19 patients (63%); this group had lower CD4+ counts (40 ± 33 vs. 139 ± 78 cel/μL) and greater disseminated involvement. After a first CM episode the relapse rate was 34%. Global mortality rate was 28% (9/32), much higher in the pre-HAART era.

CONCLUSIONS

CM morbidity and mortality is related to severe immunodeficiency, disseminated disease, high titers of antigen in CSF and delayed initiation of HAART.

Refractory and/or Relapsing Cryptococcosis Associated with Acquired Immune Deficiency Syndrome: Clinical Features, Genotype, and Virulence Factors of Cryptococcus spp. Isolates

Refractory and relapsing crytocococcosis in acquired immune deficiency syndrome (AIDS) patients have a poor prognosis. The risk factors for this complicated infection course were evaluated by comparing refractory and/or relapsing cryptococcosis in human immunodeficiency virus-coinfected patients (cohort 1) with another group of AIDS patients who adequately responded to antifungals (cohort 2). Except for one isolate of Cryptococcus gattii from a cohort 2 case, all other isolates were identified as Cryptococcus neoformans var. grubii, sex type α, genotype VNI, including Cryptococcus reisolated from the relapse or in the refractory state. No differences were observed with respect to Cryptococcus capsule size and in the melanin and phospholipase production. The cohort 1 patients presented higher prevalence of cryptococcemia, cerebral dissemination, chronic liver disease, and leucopenia, and have increased death rate. Apparently, the refractory and/or relapsing cryptococcosis in the AIDS patients were more related to the host and the extent of the infection than to the fungal characteristics.

Host immunity to Cryptococcus neoformans

Cryptococcosis is caused by the fungal genus Cryptococcus. Cryptococcosis, predominantly meningoencephalitis, emerged with the HIV pandemic, primarily afflicting HIV-infected patients with profound T-cell deficiency. Where in use, combination antiretroviral therapy has markedly reduced the incidence of and risk for disease, but cryptococcosis continues to afflict those without access to therapy, particularly in sub-Saharan Africa and Asia. However, cryptococcosis also occurs in solid organ transplant recipients and patients with other immunodeficiencies as well as those with no known immunodeficiency. This article reviews innate and adaptive immune responses to C. neoformans, with an emphasis on recent studies on the role of B cells, natural IgM and Fc gamma receptor polymorphisms in resistance to cryptococcosis.

Update from the Laboratory: Clinical Identification and Susceptibility Testing of Fungi and Trends in Antifungal Resistance

Despite the availability of new diagnostic assays and broad-spectrum antifungal agents, invasive fungal infections remain a significant challenge to clinicians and are associated with marked morbidity and mortality. In addition, the number of etiologic agents of invasive mycoses has increased accompanied by an expansion in the immunocompromised patient populations, and the use of molecular tools for fungal identification and characterization has resulted in the discovery of several cryptic species. This article reviews various methods used to identify fungi and perform antifungal susceptibility testing in the clinical laboratory. Recent developments in antifungal resistance are also discussed.

[Cryptococcosis during HIV infection]

Cryptococcosis is a cosmopolitan fungal serious condition due to an encapsulated yeast Cryptococcus neoformans. This is the systemic fungal infection the most common in HIV infection. This yeast is present in the environment and its main entrance in the body is the respiratory tract. Its gravity is linked to its tropism for the central nervous system. It generally affects subjects with severe deficit of cellular immunity and in particular, patients living with HIV. The diagnosis of neuromeningeal cryptococcosis is based on the detection of encapsulated yeasts at microscopic examination of cerebrospinal fluid, the detection of capsular polysaccharide antigen in serum or cerebrospinal fluid, but especially on the culture. A staging is always essential. The prognosis is severe. The control of intracranial hypertension is a major element of prognosis.

LATERAL FLOW ASSAY FOR CRYPTOCOCCAL ANTIGEN: AN IMPORTANT ADVANCE TO IMPROVE THE CONTINUUM OF HIV CARE AND REDUCE CRYPTOCOCCAL MENINGITIS-RELATED MORTALITY

AIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA) was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered). CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is useful for the diagnosis of disease caused by Cryptococcus species. The CrAg LFA has better analytical sensitivity for C. gattii than CrAg-latex or EIA. Prevention of cryptococcal disease is new application of CrAg LFA via screening of blood for subclinical infection in asymptomatic HIV-infected persons with CD4 counts < 100 cells/mL who are not receiving effective antiretroviral therapy. CrAg screening of leftover plasma specimens after CD4 testing can identify persons with asymptomatic infection who urgently require pre-emptive fluconazole, who will otherwise progress to symptomatic infection and/or die.

Cryptococcal Meningitis: Diagnosis and Management Update

Recent advances in the diagnosis and management of cryptococcal meningitis are promising and have been improving long-term survival. Point of care testing has made diagnosing cryptococcal meningitis rapid, practical, and affordable. Targeted screening and treatment programs for cryptococcal antigenemia are a cost effective method for reducing early mortality on antiretroviral therapy (ART). Optimal initial management with amphotericin and flucytosine improves survival against alternative therapies, although amphotericin is difficult to administer and flucytosine is not available in middle or low income countries, where cryptococcal meningitis is most prevalent. Controlling increased intracranial pressure with serial therapeutic lumbar punctures has a proven survival benefit. Delaying ART initiation for 4 weeks after the diagnosis of cryptococcal meningitis is associated with improved survival. Fortunately, new approaches have been leading the way toward improving care for cryptococcal meningitis patients. New trials utilizing different combinations of antifungal therapy are reviewed, and we summarize the efficacy of different regimens.

Cryptococcal Antigenemia in Immunocompromised Human Immunodeficiency Virus Patients in Rural Tanzania: A Preventable Cause of Early Mortality

Cryptococcal antigenemia was prevalent and an independent predictor of mortality/loss-to-follow-up in this Tanzanian cohort of ART-naïve HIV-infected individuals with CD4 <150 cells/μL. Fluconazole decreased mortality/loss-to-follow-up. These findings support the urgent adoption of the CD4-targeted cryptococcal antigen screening recommendations in Tanzania.

Background. Cryptococcal meningitis is a leading cause of death in people living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome. The World Health Organizations recommends pre-antiretroviral treatment (ART) cryptococcal antigen (CRAG) screening in persons with CD4 below 100 cells/µL. We assessed the prevalence and outcome of cryptococcal antigenemia in rural southern Tanzania.

Methods. We conducted a retrospective study including all ART-naive adults with CD4 <150 cells/µL prospectively enrolled in the Kilombero and Ulanga Antiretroviral Cohort between 2008 and 2012. Cryptococcal antigen was assessed in cryopreserved pre-ART plasma. Cox regression estimated the composite outcome of death or loss to follow-up (LFU) by CRAG status and fluconazole use.

Results. Of 750 ART-naive adults, 28 (3.7%) were CRAG-positive, corresponding to a prevalence of 4.4% (23 of 520) in CD4 <100 and 2.2% (5 of 230) in CD4 100–150 cells/µL. Within 1 year, 75% (21 of 28) of CRAG-positive and 42% (302 of 722) of CRAG-negative patients were dead or LFU (P<.001), with no differences across CD4 strata. Cryptococcal antigen positivity was an independent predictor of death or LFU after adjusting for relevant confounders (hazard ratio [HR], 2.50; 95% confidence interval [CI], 1.29–4.83; P = .006). Cryptococcal meningitis occurred in 39% (11 of 28) of CRAG-positive patients, with similar retention-in-care regardless of meningitis diagnosis (P = .8). Cryptococcal antigen titer >1:160 was associated with meningitis development (odds ratio, 4.83; 95% CI, 1.24–8.41; P = .008). Fluconazole receipt decreased death or LFU in CRAG-positive patients (HR, 0.18; 95% CI, .04–.78; P = .022).

Conclusions. Cryptococcal antigenemia predicted mortality or LFU among ART-naive HIV-infected persons with CD4 <150 cells/µL, and fluconazole increased survival or retention-in-care, suggesting that targeted pre-ART CRAG screening may decrease early mortality or LFU. A CRAG screening threshold of CD4 <100 cells/µL missed 18% of CRAG-positive patients, suggesting guidelines should consider a higher threshold.