Managing cryptococcosis in the immunocompromised host

Nomogram to Predict the Outcome of Ventriculoperitoneal Shunt Among Patients with Non-HIV Cryptococcal Meningitis

BACKGROUND

The ventriculoperitoneal (VP) shunt is widely acknowledged as a treatment option for managing intracranial hypertension resulting from non-human immunodeficiency virus (HIV) cryptococcal meningitis (CM). Nonetheless, there is currently no consensus on the appropriate surgical indications for this procedure. Therefore, it is crucial to conduct a preoperative evaluation of patient characteristics and predict the outcome of the VP shunt to guide clinical treatment effectively.

METHODS

A retrospective analysis was conducted on data from 85 patients with non-HIV CM who underwent VP shunt surgery at our hospital. The analysis involved studying demographic data, preoperative clinical manifestations, cerebrospinal fluid (CSF) characteristics, and surgical outcomes and comparisons between before and after surgery. A nomogram was developed and evaluated.

RESULTS

The therapy outcomes of 71 patients improved, whereas 14 cases had worse outcomes. Age, preoperative cryptococcus count, and preoperative CSF protein levels were found to influence the surgical outcome. The nomogram exhibited exceptional predictive performance (area under the curve = 0.896, 95% confidence interval: 0.8292-0.9635). Internal validation confirmed the nomogram's excellent predictive capabilities. Moreover, decision curve analysis demonstrated the nomogram's practical clinical utility.

CONCLUSIONS

The surgical outcome of VP shunt procedures patients with non-HIV CM was associated with age, preoperative cryptococcal count, and preoperative CSF protein levels. We developed a nomogram that can be used to predict surgical outcomes in patients with non-HIV CM.

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.

Disseminated cryptococcal infection with pulmonary involvement presenting as diffuse cavitary nodules in an immunocompromised patient: a case report

BACKGROUND

Disseminated cryptococcal infection is especially prone to occur in immunosuppressed hosts. We herein report the case of an immunosuppressed girl with disseminated cryptococcal infection in whom pulmonary cryptococcosis (PC) presented as diffuse cavitary pulmonary nodules, a finding which has rarely been reported.

CASE PRESENTATION

A 16-year-old immunocompromised girl presented with fever and a non-productive cough. A chest computed tomography (CT) scan revealed diffuse pulmonary nodules with cavities. Subsequent results were consistent with disseminated cryptococcosis with Cryptococcus identified in her blood, bone marrow and cerebrospinal fluid cultures. Thus, the patient was diagnosed with disseminated cryptococcal infection with PC, cryptococcus meningitis, cryptococcus osteomyelitis and cryptococcus sepsis. After antifungal treatment, the patient demonstrated both clinical and chest radiological improvement.

CONCLUSION

The atypical clinical manifestations of a disseminated cryptococcal infection and the rare manner of chest CT findings of PC reported in our case are easy to misdiagnose. It is necessary to carry out a thorough search for a definitive diagnosis using various methods.

Potential Predictors and Survival Analysis of the Relapse of HIV-Associated Cryptococcal Meningitis: A Retrospective Study

Objective: We intend to investigate the relapse of HIV-associated cryptococcal meningitis (CM), assess potential predictors and conduct survival analysis, with a view to establishing a valid reference for the management of the relapse of CM.

Method: This is a retrospective study in Chinese patients with HIV-associated CM and those who experience relapse of CM. Baseline demographic, laboratory and clinical characteristics of patients with HIV-associated CM were collected. Predictors for relapse of HIV-associated CM were analyzed using univariate and multivariate logistic regression. Survival probability in relapse cases was determined by Kaplan-Meier survival curves.

Results: During the study period, 87 of 348 (25.0%) HIV patients experienced the relapse of CM. CD4+ T-cell counts, antiretroviral therapy (ART) status and the time from symptom onset to presentation were all statistically associated with the relapse of CM (p = 0.013, 0.018 and 0.042, respectively). The overall survival among 46 HIV CM relapse patients whose survival information were obtained, was 78.3%. The proportion of patients who died after antifungal treatment for CM was greater in those whose interval from symptom onset to presentation ≥4 weeks, compared with those <4 weeks (p = 0.0331).

Conclusions: In order to reduce the relapse of CM and increase the survival possibility of these patients, we can promote the importance of ART before CM occurs, emphasize timely consultation when any CM-associated clinical symptoms occurs, and individualized the timing of ART initiation according to indicators which can reflect the severity of CM.

Magnitude of Cryptococcosis among HIV patients in sub-Saharan Africa countries: a systematic review and meta-analysis

Background

Cryptococcus is encapsulated opportunistic yeast that causes life threatening meningoencephalitis of patients with human immunodeficiency virus (HIV). The magnitude of Cryptococcosis among HIV patients varies from 1–10% in Western countries as opposed to almost a one third of HIV-infected individuals in sub-Saharan Africa where it is associated with high mortality.

Methodology

By using key terms “Cryptococcosis among HIV patients in sub-saharan Africa countries”, articles that published in different journals from 2010–2017 searched on Pub-Med and Google scholar database. Those freely accessible and included the prevalence of Cryptococcosis in the result section, their PDF file was downloaded and the result extracted manually and presented in table. Articles that did not report the prevalence of Cryptococcosis, with a study design otherthan cross sectional, or a sample size less than 100, and those duplicated in the same study area and period by the same authors were excluded. The article selection followed the PRISMA guidelines and meta- analysis was performed using OpenMeta(analyst).

Results

The overall pooled magnitude of Cryptococcosis among HIV patients in sub saharan African countries was 8.3% (95%CI 6.1–10.5%). The highest prevalence was from Uganda (19%) and the least was from Ethiopia at 1.6%. There was 87.2 % of substantial heterogeneity among the studies with p-value<0.001. The symmetry ofthe forest plot showed that there was little publication bias. The most commonly used method for diagnosis of Cryptococcosis was lateral flow assay and latex agglutination test and culture was the least method employed.

Conclusion

The overall pooled magnitude of Cryptococcosisis high among HIV patients in sub-Saharan African countries. The studies showed substantial heterogeneity, and little publication bias. Most of the studies relied on LFA & LA that showed the scarcity of facilities for fungal culture. Therefore, paying attention to screening HIV patients; those with signs and symptoms of meningitis may help to reduce the loss of HIV patients.

Viral, bacterial, and fungal infections of the oral mucosa: Types, incidence, predisposing factors, diagnostic algorithms, and management

For millions of years, microbiota residing within us, including those in the oral cavity, coexisted in a harmonious symbiotic fashion that provided a quintessential foundation for human health. It is now clear that disruption of such a healthy relationship leading to microbial dysbiosis causes a wide array of infections, ranging from localized, mild, superficial infections to deep, disseminated life-threatening diseases. With recent advances in research, diagnostics, and improved surveillance we are witnessing an array of emerging and re-emerging oral infections and orofacial manifestations of systemic infections. Orofacial infections may cause significant discomfort to the patients and unnecessary economic burden. Thus, the early recognition of such infections is paramount for holistic patient management, and oral clinicians have a critical role in recognizing, diagnosing, managing, and preventing either new or old orofacial infections. This paper aims to provide an update on current understanding of well-established and emerging viral, bacterial, and fungal infections manifesting in the human oral cavity.

Factors Associated With Ventriculoperitoneal Shunt Placement in Patients With Cryptococcal Meningitis

Objective

Increased intracranial pressure (ICP) is an important complication of cryptococcal meningitis (CM) and impacts morbidity and mortality. Factors associated with permanent ventriculoperitoneal (VP) shunt placement are poorly characterized.

Method

We conducted a retrospective cohort study of patients with CM at the University of Alabama at Birmingham from 1996 through 2015. Characteristics of patients at time of CM diagnosis who did and did not receive a VP shunt were compared with use of the 2-group chi-square test or Fisher exact test for categorical variables and the 2-group t test for continuous variables. Stepwise logistic regression analysis was used to determine predictors of shunt placement.

Results

Of 422 patients with cryptococcosis, 257 (60.9%) had CM. Mean age was 47.7 years, 71.6% were male, and 44.4% were African American. The most common underlying conditions were HIV (42.4%), solid organ transplantation (29.6%), and corticosteroid use (34.2%). Forty-four (17.1%) received a VP shunt a median of 17 days (range, 1-320 days) post-diagnosis. By multivariable analysis, baseline opening pressure >30 cm H₂O (OR, 9.4; 95% CI, 3.0, 28.8; P < .0001), being a normal host (OR, 6.3; 95% CI, 1.5, 26.1; P = .011) and hydrocephalus (OR, 4.9, 95% CI, 1.3, 17.9); P = .017) were associated with increased odds of shunting (Table 2). In contrast, age (OR, 0.96; 95% CI, 0.92, 0.99; P = .037) and male gender (OR, 0.18; 95% CI, 0.06, 0.55; P = .023) were associated with decreased odds of shunting.

Conclusions

Identification of factors at time of CM diagnosis associated with need for permanent VP shunt placement may allow for earlier, more aggressive treatment and potentially improve outcomes associated with increased ICP from cryptococcal meningitis.

Concomitant severe influenza and cryptococcal infections: A case report and literature review

Concomitant influenza and cryptococcal infections are rare. Herein, we describe an unusual case of an avian influenza A (H7N9) infection with several severe mixed bacterial infections and systemic super-infection with Cryptococcus neoformans presenting as ventilator-associated pneumonia (VAP) and bloodstream infection in a previously immunocompetent man during hospitalization.A 58-year-old man was admitted to our hospital complaining of hyperpyrexia, dyspnoea, cough, and phlegm with blood. A chest computed tomography scan revealed multiple ground-glass opacities and consolidation in both lungs with right pleural effusion. An initial sputum test was positive for influenza A (H7N9) virus. After antiviral treatment and other supportive measures, the patient's condition improved. However, the patient's condition deteriorated again approximately 2 weeks after admission, and bronchoalveolar lavage fluid (BALF) and blood cultures were positive for C. neoformans. Therapy with intravenous liposomal amphotericin B and fluconazole was started. After a 2-week antifungal treatment, BALF and blood cultures were negative for C. neoformans. However, the patient had persistent lung infiltrates with severe pulmonary fibrosis with a prolonged course of disease. On hospital day 40, BALF and blood cultures were both positive for multidrug-resistant Stenotrophomonas maltophilia. Finally, the patient developed septic shock, disseminated intravascular coagulation and multi-organ failure and succumbed to treatment failure.Cryptococcal infection can occur in patients with severe influenza during hospitalization with a more severe condition, and the clinician should be aware of this infection.

Cerebrospinal fluid cytokine profiles predict risk of early mortality and immune reconstitution inflammatory syndrome in HIV-associated cryptococcal meningitis

Understanding the host immune response during cryptococcal meningitis (CM) is of critical importance for the development of immunomodulatory therapies. We profiled the cerebrospinal fluid (CSF) immune-response in ninety patients with HIV-associated CM, and examined associations between immune phenotype and clinical outcome. CSF cytokine, chemokine, and macrophage activation marker concentrations were assayed at disease presentation, and associations between these parameters and microbiological and clinical outcomes were examined using principal component analysis (PCA). PCA demonstrated a co-correlated CSF cytokine and chemokine response consisting primarily of Th1, Th2, and Th17-type cytokines. The presence of this CSF cytokine response was associated with evidence of increased macrophage activation, more rapid clearance of Cryptococci from CSF, and survival at 2 weeks. The key components of this protective immune-response were interleukin (IL)-6 and interferon-γ, IL-4, IL-10 and IL-17 levels also made a modest positive contribution to the PC1 score. A second component of co-correlated chemokines was identified by PCA, consisting primarily of monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α). High CSF chemokine concentrations were associated with low peripheral CD4 cell counts and CSF lymphocyte counts and were predictive of immune reconstitution inflammatory syndrome (IRIS). In conclusion CSF cytokine and chemokine profiles predict risk of early mortality and IRIS in HIV-associated CM. We speculate that the presence of even minimal Cryptococcus-specific Th1-type CD4+ T-cell responses lead to increased recruitment of circulating lymphocytes and monocytes into the central nervous system (CNS), more effective activation of CNS macrophages and microglial cells, and faster organism clearance; while high CNS chemokine levels may predispose to over recruitment or inappropriate recruitment of immune cells to the CNS and IRIS following peripheral immune reconstitution with ART. These results provide a rational basis for future studies of immune modulation in CM, and demonstrate the potential of baseline immune profiling to identify CM patients most at risk of mortality and subsequent IRIS.

Cryptococcal meningitis is a severe opportunistic infection, estimated to kill several hundred thousand HIV-infected individuals each year. One of the factors contributing to this high death toll is the inadequacy of antifungal treatments. As few novel antifungal drugs are being developed, several groups have started to investigate the potential of immune modulation, with treatments designed to change the patient’s immune response to infection. However, our understanding of the immune response to cryptococcal infection in HIV-infected patients, and how these responses impact on clinical outcomes, is limited. In this study, we took advantage of the fact that we can sample cerebrospinal fluid (CSF) from the site of the infection in patients when they develop cryptococcal meningitis. We undertook a detailed analysis measuring levels of immune response parameters in the CSF of these patients, and demonstrated that there were several distinct components of the immune response. Variations in these responses were associated with both the rate at which patients cleared their infection during treatment, and with mortality. Our results provide a basis for the development of future immunomodulatory therapies, and may allow identification of patients most at risk of dying, enabling more intensive treatments to be given to those at highest risk.

Cryptococcus neoformans meningitis with negative cryptococcal antigen: Evaluation of a new immunochromatographic detection assay

Detection of cryptococcal antigen in serum or cerebrospinal fluid allows cryptococcal meningitis diagnosis within few hours with >90% sensitivity. In an HIV-positive patient with Cryptococcus neoformans meningitis, initial antigen detection by immunoagglutination was negative. We thus evaluated a new immunochromatographic detection assay that exhibited a higher sensitivity.

Cryptococcus neoformans meningoencephalitis in a patient with polyarteritis nodosa

Case of 59-year-old male with chronic obstructive pulmonary disease and a number of comorbidities, who has developed meningoencephalitis caused by Cryptococcus neoformans var. grubii with polyarteritis nodosa diagnosed during hospitalization, was presented. Before evidence of meningoencephalitis, the patient was being treated with ketoconazole and low doses of fluconazole (200 mg/day) for alleged candidiasis. The dosage was increased (800 mg/day) following laboratory diagnosis of C. neoformans based on positive latex agglutination test and biochemical identification of encapsulated yeast isolated from the blood and CSF. Later, the yeast identification was confirmed by sequencing analysis. Owing to inadequate clinical response, fluconazole therapy was switched to voriconazole (400 mg/day) and later to intravenous amphotericin B (1.0 mg/kg per day). Despite of a temporary stabilization and improvement, which correlated with decline of cryptococcal antigen titers (from 1:1024 to 1:8), after 6 weeks, the patient's underlying condition deteriorated due to severe pancolitis and serious nosocomial bacterial infections. The patient died of multiorgan failure several days later. Our case demonstrates a possible connection between the development of life-threatening cryptococcosis and an autoimmune vasculitis disease and emphasizes that the outcome of the management of cryptococcal meningoencephalitis is highly dependent on early diagnosis, adequate treatment, including dosage, and last but not least control of underlying disease and risk factors.

Very low levels of 25-hydroxyvitamin D are not associated with immunologic changes or clinical outcome in South African patients with HIV-associated cryptococcal meningitis

Vitamin D deficiency may increase susceptibility to opportunistic infections in HIV-infected individuals. We found no evidence that vitamin D deficiency increases risk of cryptococcal meningitis or leads to impaired immune responses or microbiological clearance in HIV-infected patients with cryptococcal meningitis.

Background. Vitamin D deficiency is associated with impaired immune responses and increased susceptibility to a number of intracellular pathogens in individuals infected with human immunodeficiency virus (HIV). It is not known whether such an association exists with Cryptococcus neoformans.

Methods. Levels of 25-hydroxyvitamin D (25[OH]D) were measured in 150 patients with cryptococcal meningitis (CM) and 150 HIV-infected controls in Cape Town, South Africa, and associations between vitamin D deficiency and CM were examined. The 25-hydroxyvitamin D levels and cryptococcal notifications were analyzed for evidence of reciprocal seasonality. Associations between 25(OH)D levels and disease severity, immune responses, and microbiological clearance were investigated in the patients with CM.

Results. Vitamin D deficiency (plasma 25[OH]D ≤50 nmol/L) was present in 74% of patients. Vitamin D deficiency was not associated with CM (adjusted odds ratio, 0.93 [95% confidence interval, .6–1.6]; P = .796). Levels of 25(OH)D showed marked seasonality, but no reciprocal seasonality was seen in CM notifications. No significant associations were found between 25(OH)D levels and fungal burden or levels of tumor necrosis factor α, interferon γ, interleukin 6, soluble CD14, or neopterin in cerebrospinal fluid. Rates of fungal clearance did not vary according to vitamin D status.

Conclusions. Vitamin D deficiency does not predispose to the development of CM, or lead to impaired immune responses or microbiological clearance in HIV-infected patients with CM.

Multilocus sequence typing of serially collected isolates of Cryptococcus from HIV-infected patients in South Africa

Patients with cryptococcal meningitis in sub-Saharan Africa frequently relapse following treatment. The natural history and etiology of these recurrent episodes warrant investigation. Here, we used multilocus sequence typing (MLST) to compare the molecular genotypes of strains of Cryptococcus neoformans and Cryptococcus gattii isolated from serial episodes of cryptococcal meningitis that were separated by at least 110 days. The most common MLST genotypes among the isolates were the dominant global clinical genotypes (M5 and M4) of molecular type VNI, as well as the VNI genotypes apparently restricted to southern Africa. In addition, there was considerable genetic diversity among these South African isolates, as 15% of the patients had unique genotypes. Eleven percent of the patients were reinfected with a genetically different strain following their initial diagnosis and treatment. However, the majority of serial episodes (89%) were caused by strains with the same genotype as the original strain. These results indicate that serial episodes of cryptococcosis in South Africa are frequently associated with persistence or relapse of the original infection. Using a reference broth microdilution method, we found that the serial isolates of 11% of the patients infected with strains of C. neoformans var. grubii with identical genotypes exhibited ≥4-fold increases in the MICs to fluconazole. Therefore, these recurrent episodes may have been precipitated by inadequate induction or consolidation of antifungal treatment and occasionally may have been due to increased resistance to fluconazole, which may have developed during the chronic infection.

Persistent Cryptococcal Brain Infection despite Prolonged Immunorecovery in an HIV-Positive Patient

Background. HIV-positive people starting combined antiretroviral therapy may develop immune reconstitution to latent or treated opportunistic infections. Immune reconstitution to cerebral Cryptococcus is poorly understood and can be fatal. Case Presentation. A 33-year-old Zimbabwean female presented with cryptococcal meningitis and newly diagnosed HIV with a CD4 count of 51 cells/μL (4%). She was treated with amphotericin and flucytosine. Combined antiretroviral therapy was started four weeks later and she showed early improvement. However, over the ensuing 18 months, her clinical course was marked by periodic worsening with symptoms resembling cryptococcal meningitis despite having achieved CD4 counts ≥400 cells/μL. Although initially treated for relapsing cryptococcal immune reconstitution syndrome, a brain biopsy taken 17 months after initial presentation showed budding Cryptococci. Conclusion. This unusually protracted case highlights the difficulties in differentiating relapsing cryptococcal meningitis from immune reconstitution and raises questions concerning the optimum timing of initiation of combined antiretroviral therapy in such patients.

Stress signaling pathways for the pathogenicity of Cryptococcus

Sensing, responding, and adapting to the surrounding environment are crucial for all living organisms to survive, proliferate, and differentiate in their biological niches. This ability is also essential for Cryptococcus neoformans and its sibling species Cryptococcus gattii, as these pathogens have saprobic and parasitic life cycles in natural and animal host environments. The ability of Cryptococcus to cause fatal meningoencephalitis is highly related to its capability to remodel and optimize its metabolic and physiological status according to external cues. These cues act through multiple stress signaling pathways through a panoply of signaling components, including receptors/sensors, small GTPases, secondary messengers, kinases, transcription factors, and other miscellaneous adaptors or regulators. In this minireview, we summarize and highlight the importance of several stress signaling pathways that influence the pathogenicity of Cryptococcus and discuss future challenges in these areas.

Cryptococcosis: epidemiology, fungal resistance, and new alternatives for treatment

Cryptococcosis is an important systemic mycosis and the third most prevalent disease in human immunodeficiency virus (HIV)-positive individuals. The incidence of cryptococcosis is high among the 25 million people with HIV/acquired immunodeficiency syndrome (AIDS), with recent estimates indicating that there are one million cases of cryptococcal meningitis globally per year in AIDS patients. In Cryptococcus neoformans, resistance to azoles may be associated with alterations in the target enzyme encoded by the gene ERG11, lanosterol 14α-demethylase. These alterations are obtained through mutations, or by overexpressing the gene encoding. In addition, C. gattii and C. neoformans present a heteroresistance phenotype, which may be related to increased virulence. Other species beyond C. neoformans and C. gattii, such as C. laurentii, have been diagnosed mainly in patients with immunosuppression. Infections of C. albidus have been isolated in cats and marine mammals. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth, which is also related with increased resistance to antifungal agents. Therefore, there is a great need to search for alternative antifungal agents for these fungi. The search for new molecules is currently occurring from nanoparticle drugs of plant peptide origin. This article presents a brief review of the literature regarding the epidemiology of cryptococcosis, as well as fungal resistance and new alternatives for treatment.

[Pulmonary fungal infection in patients with AIDS]

Fungal infections are the most common opportunistic infections (OI) occurring during the course of HIV infection, though their incidence has decreased dramatically with the introduction of highly active antiretroviral therapy (cART). Most cases occur in untreated patients, noncompliant patients or patients whose multiple antiretroviral regimens have failed and they are a good marker of the severity of cellular immunodepression. Pneumocystis jiroveci pneumonia is the second most frequent OI in France and cryptococcosis remains a major problem in the Southern Hemisphere. With the increase in travel, imported endemic fungal infection can occur and may mimic other infections, notably tuberculosis. Fungal infections often have a pulmonary presentation but an exhaustive search for dissemination should be made in patients infected with HIV, at least those at an advanced stage of immune deficiency. Introduction of cART in combination with anti-fungal treatment depends on the risk of AIDS progression and on the risk of cumulative toxicity and the immune reconstitution inflammatory syndrome (IRIS) if introduced too early. Fungal infections in HIV infected patients remain a problem in the cART era. IRIS can complicate the management and requires an optimised treatment regime.

Approaches to antifungal therapies and their effectiveness among patients with cryptococcosis

The goal of this study was to determine the degree to which the persistence of cryptococcosis, overall 1-year mortality, and 1-year mortality due to cryptococcosis were influenced by initial antifungal treatment regimen in a cohort of adults with cryptococcosis treated at a tertiary care medical center. Risk factors, underlying conditions, treatment, and mortality information were obtained for 204 adults with cryptococcosis from Duke University Medical Center (DUMC) from 1996 to 2009. Adjusted risk ratios (RR) for persistence and hazard ratios (HR) for mortality were estimated for each exposure. The all-cause mortality rate among patients with nonsevere disease (20%) was similar to that in the group with disease (26%). However, the rate of cryptococcosis-attributable mortality with nonsevere disease (5%) was much lower than with severe disease (20%). Flucytosine exposure was associated with a lower overall mortality rate (HR, 0.4; 95% confidence interval [CI], 0.2 to 0.9) and attributable mortality rate (HR, 0.5; 95% CI, 0.2 to 1.2). Receiving a nonrecommended antifungal regimen was associated with a higher relative risk of persistent infection at 4 weeks (RR, 1.9; 95% CI, 0.9 to 4.3), and the rate of attributable mortality among those not receiving the recommended dose of initial therapy was higher than that of those receiving recommended dosing (HR, 2.3; 95% CI, 1.0 to 5.0). Thus, the 2010 Infectious Diseases Society of America (IDSA) guidelines are supported by this retrospective review as a best-practice protocol for cryptococcal management. Future investigations should consider highlighting the distinction between all-cause mortality and attributable mortality so as not to overestimate the true effect of cryptococcosis on patient death.

Optimal timing for antiretroviral therapy initiation in patients with HIV infection and concurrent cryptococcal meningitis

BACKGROUND

Currently, initiation of antiretroviral therapy (ART) in most patients with human immunodeficiency virus (HIV) infection is based on the CD4-positive-t-lymphocyte count. However, the point during the course of HIV infection at which ART should be initiated in patients with concurrent cryptococcal meningitis remains unclear. The aim of this systematic review was to summarise the evidence on the optimal timing of ART initiation in patients with cryptococcal meningitis for use in clinical practice and guideline development.

OBJECTIVES

To compare the clinical and immunologic outcomes for early initiation ART (less than four weeks after starting antifungal treatment) versus later initiation of HAART (four weeks or more after starting antifungal treatment) in HIV-positive patients with concurrent cryptococcal meningitis.

SEARCH METHODS

We searched the following databases from January 1980 to February 2011: PubMed, EMBASE, and WHO International Clinical Trials Registry Platform, AEGIS database for conference abstracts, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. A total of 35 full text articles were identified and supplemented by a bibliographic search. We contacted researchers and relevant organizations and checked reference lists of all included studies.

SELECTION CRITERIA

Randomized controlled trials that compared the effect of ART (consisting of three drug combinations) initiated early or delayed in HIV patients with cryptococcal meningitis.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, and graded methodological quality. Data extraction and methodological quality were checked by a third author who resolved differences when these arose. Where clinically meaningful, we performed a meta-analysis of dichotomous outcomes using the relative risk (RR) and report the 95% confidence intervals (95% CIs).

MAIN RESULTS

Two eligible randomized controlled trials were included (N = 89). In our pooled analysis, we combined the clinical data for both trials comparing early initiation ART versus delayed initiation of ART. There was no statistically significant difference in mortality (RR=1.40, 95% CI [0.42, 4.68]) in the group with early initiation of ART compared to the group with delayed initiation of ART.

AUTHORS' CONCLUSIONS

This systematic review shows that there is insufficient evidence in support of either early or late initiation of ART. For the moment, because of the high risk of immune reconstitution syndrome in patients with cryptococcal meningitis, we recommend that ART initiation should be delayed until there is evidence of a sustained clinical response to antifungal therapy. However, large studies with appropriate comparison groups, and adequate follow-up are warranted to provide the evidence base for effective decision making.

Identification of genes from the fungal pathogen Cryptococcus neoformans related to transmigration into the central nervous system

Background

A mouse brain transmigration assessment (MBTA) was created to investigate the central nervous system (CNS) pathogenesis of cryptococcal meningoencephalitis.

Methodology/Principal Findings

Two cryptococcal mutants were identified from a pool of 109 pre-selected mutants that were signature-tagged with the nourseothricin acetyltransferase (NAT) resistance cassette. These two mutants displayed abnormal transmigration into the central nervous system. One mutant displaying decreased transmigration contains a null mutation in the putative FNX1 gene, whereas the other mutant possessing a null mutation in the putative RUB1 gene exhibited increased transmigration into the brain. Two macrophage adhesion-defective mutants in the pool, 12F1 and 3C9, showed reduced phagocytosis by macrophages, but displayed no defects in CNS entry suggesting that transit within macrophages (the “Trojan horse” model of CNS entry) is not the primary mechanism for C. neoformans migration into the CNS in this MBTA.

Conclusions/Significance

This research design provides a new strategy for genetic impact studies on how Cryptococcus passes through the blood-brain barrier (BBB), and the specific isolated mutants in this assay support a transcellular mechanism of CNS entry.

Comparison and temporal trends of three groups with cryptococcosis: HIV-infected, solid organ transplant, and HIV-negative/non-transplant

BACKGROUND

The Infectious Disease Society of America (IDSA) 2010 Clinical Practice Guidelines for the management of cryptococcosis outlined three key populations at risk of disease: (1) HIV-infected, (2) transplant recipient, and (3) HIV-negative/non-transplant. However, direct comparisons of management, severity and outcomes of these groups have not been conducted.

METHODOLOGY/PRINCIPAL FINDINGS

Annual changes in frequency of cryptococcosis diagnoses, cryptococcosis-attributable mortality and mortality were captured. Differences examined between severe and non-severe disease within the context of the three groups included: demographics, symptoms, microbiology, clinical management and treatment. An average of nearly 15 patients per year presented at Duke University Medical Center (DUMC) with cryptococcosis. Out of 207 study patients, 86 (42%) were HIV-positive, 42 (20%) were transplant recipients, and 79 (38%) were HIV-negative/non-transplant. HIV-infected individuals had profound CD4 lymphocytopenia and a majority had elevated intracranial pressure. Transplant recipients commonly (38%) had renal dysfunction. Nearly one-quarter (24%) had their immunosuppressive regimens stopped or changed. The HIV-negative/non-transplant population reported longer duration of symptoms than HIV-positive or transplant recipients and 28% (22/79) had liver insufficiency or underlying hematological malignancies. HIV-positive and HIV-negative/non-transplant patients accounted for 89% of severe disease cryptococcosis-attributable deaths and 86% of all-cause mortality.

CONCLUSIONS/SIGNIFICANCE

In this single-center study, the frequency of cryptococcosis did not change in the last two decades, although the underlying case mix shifted (fewer HIV-positive cases, stable transplant cases, more cases with neither). Cryptococcosis had a relatively uniform and informed treatment strategy, but disease-attributable mortality was still common.

Hydroxyurea treatment inhibits proliferation of Cryptococcus neoformans in mice

The fungal pathogen Cryptococcus neoformans (Cn) is a serious threat to immunocompromised individuals, especially for HIV patients who develop meningoencephalitis. For effective cryptococcal treatment, novel antifungal drugs or innovative combination therapies are needed. Recently, sphingolipids have emerged as important bioactive molecules in the regulation of microbial pathogenesis. Previously we reported that the sphingolipid pathway gene, ISC1, which is responsible for ceramide production, is a major virulence factor in Cn infection. Here we report our studies of the role of ISC1 during genotoxic stress induced by the antineoplastic hydroxyurea (HU) and methyl methanesulfonate (MMS), which affect DNA replication and genome integrity. We observed that Cn cells lacking ISC1 are highly sensitive to HU and MMS in a rich culture medium. HU affected cell division of Cn cells lacking the ISC1 gene, resulting in cell clusters. Cn ISC1, when expressed in a Saccharomyces cerevisiae (Sc) strain lacking its own ISC1 gene, restored HU resistance. In macrophage-like cells, although HU affected the proliferation of wild type (WT) Cn cells by 50% at the concentration tested, HU completely inhibited Cn isc1Δ cell proliferation. Interestingly, our preliminary data show that mice infected with WT or Cn isc1Δ cells and subsequently treated with HU had longer lifespans than untreated, infected control mice. Our work suggests that the sphingolipid pathway gene, ISC1, is a likely target for combination therapy with traditional drugs such as HU.

Retrospective analysis of 76 immunocompetent patients with primary pulmonary cryptococcosis

BACKGROUND

Pulmonary cryptococcosis typically occurs in immunocompromised patients, but it can also occur in immunocompetent patients. Our objective was to describe the clinical manifestations, diagnosis, and management of primary pulmonary cryptococcosis in immunocompetent patients.

METHODS

We retrospectively reviewed the clinical data of 76 patients with primary pulmonary cryptococcosis who were admitted to our hospital from 1995 to 2010.

RESULTS

Pulmonary cryptococcosis was pathologically proven in all patients. Mean patient age was 42.5 years and 55 patients (72%) were male. The major clinical manifestations were cough (47 pts, 62%), expectoration (29 pts, 38%), fever (16 pts, 21%), chest pain (15 pts, 20%), dyspnea (17 pts, 22%), and emaciation (10 pts, 13%). Eighteen patients (24%) were asymptomatic. Most patients were admitted due to shadows on chest X-rays. Lesions were more common in the lower lung (60 pts, 78.9%) than in the upper lung (25 pts, 32.9%). More lesions (28 pts, 37%) were characterized by patchy consolidations. Pulmonary cryptococcosis was confirmed histologically among all patients. Surgical removal of lesions or treatment with fluconazole and other antifungal agents for complete courses led to favorable outcomes for most patients.

CONCLUSIONS

Primary pulmonary cryptococcosis was found mainly in immunocompetent patients aged <50 years without preexisting lung disease. Shadow on the chest X-ray is the predominant feature. Treatment with a complete course of fluconazole and/or other antifungal agents can achieve favorable outcome.

Recent advances in management of cryptococcal meningitis: commentary

Cryptococcal meningitis remains a substantial health burden with high morbidity, particularly in developing countries. Antifungal treatment regimens are guided by host factors, severity of illness (including presence of complications), and causative cryptococcal species. Recent clinical studies indicate the need for rapidly fungicidal induction therapy regimens using amphotericin B in combination with flucytosine for optimal outcomes. Maintenance therapy with fluconazole is necessary until recovery of immune function. Cryptococcus gattii meningitis requires prolonged induction/eradication therapy. Prompt control of raised intracranial pressure or hydrocephalus is essential. Clinicians should be vigilant for immune restoration-like features. Adjuvant surgery, corticosteroids, and/or recombinant interferon-gamma may be required for large cryptococcomas, cerebral edema, or refractory infection.

An update on Cryptococcus among HIV-infected patients

Cryptococcus remains an important opportunistic infection in HIV patients despite considerable declines in prevalence during the highly active antiretroviral therapy era. This is particularly apparent in sub-Saharan Africa, where Cryptococcus continues to cause significant mortality and morbidity. This review discusses the microbiology, epidemiology, pathogenesis and clinical presentation of cryptococcal infections in HIV patients. Additionally, a detailed approach to the management of cryptococcosis is provided.

Treatment of cryptococcal meningitis in resource limited settings

PURPOSE OF REVIEW

Cryptococcal meningitis most commonly occurs in advanced HIV. Although diminishing in the developed world with antiretroviral therapy (ART), it remains a major problem in resource-limited settings. ART rollout will improve long-term HIV survival if opportunistic infections are effectively treated. Considering cryptococcal meningitis in that context, this review addresses excess morbidity and mortality in developing countries, treatment in areas of limited drug availability and challenges posed by combined anticryptococcal and HIV therapy.

RECENT FINDINGS

From Early Fungicidal Activity (EFA) studies, amphotericin B-flucytosine is best induction therapy but often unavailable; high dose amphotericin B monotherapy may be feasible in some settings. Where fluconazole is the only option, higher doses are more fungicidal. Serum cryptococcal antigen testing may identify patients at highest disease risk and primary prophylaxis is effective; the clinical role of such interventions needs to be established. Timing of ART introduction remains controversial; early initiation risks Immune Reconstitution Disease (IRD) delays may increase mortality.

SUMMARY

Amphotericin B based treatment is appropriate where possible. More studies are needed to optimize fluconazole monotherapy doses. Other research priorities include management of raised intracranial pressure, appropriate ART initiation and IRD treatment. Studies should focus on developing countries where problems are greatest.