Description of Cryptococcosis Following SARS-CoV-2 Infection: A Disease Survey Through the Mycosis Study Group Education and Research Consortium (MSG-19)

BACKGROUND

Invasive fungal infections have been described throughout the COVID-19 pandemic. Cryptococcal disease after infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported in several isolated case reports and 1 larger case series. We sought to describe cryptococcal infections following SARS-CoV-2 through establishing a database to investigate underlying risk factors, disease manifestations, and outcomes.

METHODS

We created a crowdsourced call for cases solicited through the Mycoses Study Group Education and Research Consortium, the Centers for Disease Control and Prevention Emerging Infectious Diseases Network, and infectious diseases Twitter groups. Data were collected in a web-based and secure REDCap survey without personal identifiers.

RESULTS

Sixty-nine cases were identified and submitted by 29 separate institutional sites. Cryptococcosis was diagnosed a median of 22 days (interquartile range, 9-42 days) after SARS-CoV-2 infection. Mortality among those with available follow-up was 72% (26/36) for the immunocompetent group and 48% (15/31) for the immunocompromised group (likelihood ratio, 4.01; P = .045). We observed a correlation between disease manifestation (central nervous system infection, proven/probable disseminated disease, and respiratory) and mortality (P = .002).

CONCLUSIONS

The mortality rate of 59% for patients with cryptococcosis following SARS-CoV-2 is higher than that of modern Cryptococcus cohorts. There was an association between immunocompromised status and cryptococcal disease manifestations as well as mortality. Moreover, our series emphasizes the need for clinical and laboratory assessment of opportunistic infections beyond 30 days when concerning symptoms develop.

HIV and fungal priority pathogens

The burden of invasive fungal infections associated with opportunistic fungal pathogens is a persistent challenge, particularly among people with advanced HIV disease. In October, 2022, WHO published the Fungal Priority Pathogens List (FPPL)-the first global effort to systematically prioritise fungal pathogens. Of the 19 pathogens in the WHO FPPL, four opportunistic pathogens in particular cause invasive diseases in people living with HIV: Cryptococcus neoformans, Histoplasma spp, Pneumocystis jirovecii, and Talaromyces marneffei. These four fungal pathogens are major causes of illness and death in people with advanced HIV and overwhelmingly affect those in low-income and middle-income countries. Access to diagnostics, improved surveillance, targeted support for innovation, and an enhanced public health focus on these diseases are needed in the effort to reduce HIV-associated deaths.

A global call for talaromycosis to be recognised as a neglected tropical disease

Talaromycosis (penicilliosis) is an invasive mycosis that is endemic in tropical and subtropical Asia. Talaromycosis primarily affects individuals with advanced HIV disease and other immunosuppressive conditions, and the disease disproportionally affects people in low-income and middle-income countries, particularly agricultural workers in rural areas during their most economically productive years. Approximately 17 300 talaromycosis cases and 4900 associated deaths occur annually. Talaromycosis is highly associated with the tropical monsoon season, when flooding and cyclones can exacerbate the poverty-inducing potential of the disease. Talaromycosis can present as localised or disseminated disease, the latter causing cutaneous lesions that are disfiguring and stigmatising. Despite up to a third of diagnosed cases resulting in death, talaromycosis has received little attention and investment from regional and global funders, policy makers, researchers, and industry. Diagnostic and treatment modalities remain extremely insufficient, however control of talaromycosis is feasible with known public health strategies. This Viewpoint is a global call for talaromycosis to be recognised as a neglected tropical disease to alleviate its impact on susceptible populations.

ECMM/ISHAM recommendations for clinical management of COVID-19 associated mucormycosis in low- and middle-income countries

Reports are increasing on the emergence of COVID-19-associated mucormycosis (CAM) globally, driven particularly by low- and middle-income countries. The recent unprecedented surge of CAM in India has drawn worldwide attention. More than 28,252 mucormycosis cases are counted and India is the first country where mucormycosis has been declared a notifiable disease. However, misconception of management, diagnosing and treating this infection continue to occur. Thus, European Confederation of Medical Mycology (ECMM) and the International Society for Human and Animal Mycology (ISHAM) felt the need to address clinical management of CAM in low- and middle-income countries. This article provides a comprehensive document to help clinicians in managing this infection. Uncontrolled diabetes mellitus and inappropriate (high dose or not indicated) corticosteroid use are the major predisposing factors for this surge. High counts of Mucorales spores in both the indoor and outdoor environments, and the immunosuppressive impact of COVID-19 patients as well as immunotherapy are possible additional factors. Furthermore, a hyperglycaemic state leads to an increased expression of glucose regulated protein (GRP- 78) in endothelial cells that may help the entry of Mucorales into tissues. Rhino-orbital mucormycosis is the most common presentation followed by pulmonary mucormycosis. Recommendations are focused on the early suspicion of the disease and confirmation of diagnosis. Regarding management, glycaemic control, elimination of corticosteroid therapy, extensive surgical debridement and antifungal therapy are the standards for proper care. Due to limited availability of amphotericin B formulations during the present epidemic, alternative antifungal therapies are also discussed.

Superiority of a Novel Mp1p Antigen Detection Enzyme Immunoassay Compared to Standard BACTEC Blood Culture in the Diagnosis of Talaromycosis

BACKGROUND

Talaromycosis is an invasive mycosis endemic in Southeast Asia and causes substantial morbidity and mortality in individuals with advanced human immunodeficiency virus (HIV) disease. Current diagnosis relies on isolating Talaromyces marneffei in cultures, which takes up to 14 days and is detectable only during late-stage infection, leading to high mortality.

METHODS

In this retrospective case-control study, we assessed the accuracy of a novel Mp1p antigen-detecting enzyme immunoassay (EIA) in stored plasma samples of 372 patients who had culture-proven talaromycosis from blood or sterile body fluids (reference standard) and 517 individuals without talaromycosis (338 healthy volunteers; 179 with other infections). All participants were recruited between 2011 and 2017 in Vietnam.

RESULTS

Of cases and controls, 66.1% and 75.4%, respectively, were male; the median age was 33 and 37, respectively. All cases were HIV infected; median CD4 count was 10 cells/μL. At an optical density cutoff of 0.5, the specificity was 98.1% (95% CI, 96.3%-99.0%); the sensitivity was superior to blood culture (86.3% [95% CI, 82.3%-89.5%] vs 72.8% [95% CI, 68.0%-77.2%]) (P < .001, McNemar test). The time to diagnosis was 6 hours vs 6.6 ± 3.0 days for blood culture. Paired plasma and urine testing in the same patients (n = 269) significantly increased sensitivity compared to testing plasma alone or testing urine alone (P < .001 and P = .02, respectively, McNemar test).

CONCLUSIONS

The Mp1p EIA is highly specific and is superior in sensitivity and time to diagnosis compared to blood culture for the diagnosis of talaromycosis. Paired plasma and urine testing further increases sensitivity, introducing a new tool for rapid diagnosis, enabling early treatment and potentially reducing mortality.

Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies

Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (V_H) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without V_H-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM⁺IgD⁺CD27⁺, thus suggesting that they originated from a pool of antigen-experienced IgM⁺ or marginal zone B cells.

Cryptococcal Antigen in Serum and Cerebrospinal Fluid for Detecting Cryptococcal Meningitis in Adults Living With Human Immunodeficiency Virus: Systematic Review and Meta-Analysis of Diagnostic Test Accuracy Studies

Cryptococcal antigen (CrAg) detection could direct the timely initiation of antifungal therapy. We searched MEDLINE and Embase for studies where CrAg detection in serum/cerebrospinal fluid (CSF) and CSF fungal culture were done on adults living with human immunodeficiency virus (HIV) who had suspected cryptococcal meningitis (CM). With Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2), we evaluated the risk of bias in 11 included studies with 3600 participants, and used a random-effects meta-analysis to obtain summary sensitivity and specificity of serum and CSF CrAg, as well as agreement between CSF CrAg and CSF culture. Summary sensitivity and specificity of serum CrAg were 99.7% (97.4-100) and 94.1% (88.3-98.1), respectively, and summary sensitivity and specificity of CSF CrAg were 98.8% (96.2-99.6) and 99.3% (96.7-99.9), respectively. Agreement between CSF CrAg and CSF culture was 98% (97-99). In adults living with HIV who have CM symptoms, serum CrAg negativity may rule out CM, while positivity should prompt induction antifungal therapy if lumbar puncture is not feasible. In a first episode of CM, CSF CrAg positivity is diagnostic.

Occult Talaromyces marneffei Infection Unveiled by the Novel Mp1p Antigen Detection Assay

Talaromyces marneffei causes fatal invasive mycosis in Southeast Asia. Diagnosis by culture has limited sensitivity and can result in treatment delay. We describe the use of a novel Mp1p enzyme immunoassay (EIA) to identify blood culture-negative talaromycosis, subsequently confirmed by bone marrow cultures. This EIA has the potential to speed diagnosis, enabling early therapy initiation.

How Clean Is the Linen at My Hospital? The Mucorales on Unclean Linen Discovery Study of Large United States Transplant and Cancer Centers

Mucormycosis outbreaks have been linked to contaminated linen. We performed fungal cultures on freshly-laundered linens at 15 transplant and cancer hospitals. At 33% of hospitals, the linens were visibly unclean. At 20%, Mucorales were recovered from >10% of linens. Studies are needed to understand the clinical significance of our findings.

Complete Genome Sequences for Two Talaromyces marneffei Clinical Isolates from Northern and Southern Vietnam

Talaromyces marneffei is a thermally dimorphic fungus endemic in China and Southeast Asia that causes fatal infections in immunocompromised individuals, particularly in patients with advanced HIV disease. Here, we report the complete genome sequences of two clinical isolates from northern and southern Vietnam.

Three phylogenetic groups have driven the recent population expansion of Cryptococcus neoformans

Cryptococcus neoformans (C. neoformans var. grubii) is an environmentally acquired pathogen causing 181,000 HIV-associated deaths each year. We sequenced 699 isolates, primarily C. neoformans from HIV-infected patients, from 5 countries in Asia and Africa. The phylogeny of C. neoformans reveals a recent exponential population expansion, consistent with the increase in the number of susceptible hosts. In our study population, this expansion has been driven by three sub-clades of the C. neoformans VNIa lineage; VNIa-4, VNIa-5 and VNIa-93. These three sub-clades account for 91% of clinical isolates sequenced in our study. Combining the genome data with clinical information, we find that the VNIa-93 sub-clade, the most common sub-clade in Uganda and Malawi, was associated with better outcomes than VNIa-4 and VNIa-5, which predominate in Southeast Asia. This study lays the foundation for further work investigating the dominance of VNIa-4, VNIa-5 and VNIa-93 and the association between lineage and clinical phenotype.

Trehalose-6-phosphate synthase-deletion in Cryptococcus neoformans elicits rapid innate fungal clearance from the lungs with early neutrophil accumulation

Clearance of the invasive fungus Cryptococcus neoformans (Cn) infection requires T-cell immune responses and individuals with impaired adaptive immunity are highly vulnerable to Cn infection. The innate immune response thus may be the only functional arm against the expansion of pathogens in patients with severe T cell deficiencies. Accordingly, targeting pathways responsible for Cn-evasion of early innate defenses could rapidly resolve Cn-disease in immunocompromised patients.

Trehalose-6-phosphate synthase (TPS1), a fungal enzyme for trehalose sugar synthesis absent in mammal, was recently identified as a key virulence gene. Using a mouse model of pulmonary Cn infection, we found that TPS1-deficient Cn (tps1Δ) elicits rapid clearance by the host. Within 72 hours, tps1Δ was either completely cleared or reduced by 5 orders of magnitude, while WT-Cn expanded in the lungs of infected mice. Mechanistically, we found that rapid tps1Δ clearance was associated with early neutrophils recruitment and induction of neutrophils - recruiting CXCL1 and CXCL2. Notably, this occurred without improved Cn-killing by macrophages. Tps1Δ stains were rapidly cleared from CD4+ T cell depleted mice that receive anti-CD4 antibody treatment, suggesting that Tps1Δ clearance is independent of host adaptive immunity. Furthermore, our in vitro killing assay showed that tps1Δ was more vulnerable to neutrophils killing compared to WT strain. Together, our data revealed that cnTPS1 contributes to early innate immune evasion by inhibiting neutrophil recruitment and killing. We identify TPS1-interception as an important therapeutic strategy to both compromise the microbe fitness and to enhance efficiency of the innate defenses in C.n elimination.

Population Pharmacodynamics of Amphotericin B Deoxycholate for Disseminated Infection Caused by Talaromyces marneffei

Amphotericin B deoxycholate (DAmB) is a first-line agent for the initial treatment of talaromycosis. However, little is known about the population pharmacokinetics and pharmacodynamics of DAmB for talaromycosis. Pharmacokinetic data were obtained from 78 patients; among them, 55 patients had serial fungal CFU counts in blood also available for analysis. A population pharmacokinetic-pharmacodynamic model was fitted to the data. The relationships between the area under the concentration-time curve (AUC)/MIC and the time to blood culture sterilization and the time to death were investigated. There was only modest pharmacokinetic variability in the average AUC, with a mean ± standard deviation of 11.51 ± 3.39 mg·h/liter. The maximal rate of drug-induced kill was 0.133 log10 CFU/ml/h, and the plasma concentration of the DAmB that induced the half-maximal rate of kill was 0.02 mg/liter. Fifty percent of patients sterilized their bloodstreams by 83.16 h (range, 13 to 264 h). A higher initial fungal burden was associated with a longer time to sterilization (hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.36 to 0.70; P < 0.001). There was a weak relationship between AUC/MIC and the time to sterilization, although this did not reach statistical significance (HR, 1.03; 95% CI, 1.00 to 1.06, P = 0.091). Furthermore, there was no relationship between the AUC/MIC and time to death (HR, 0.97; 95% CI, 0.88 to 1.08; P = 0.607) or early fungicidal activity {slope = log[(0.500 - 0.003·(AUC/MIC)]; P = 0.319} adjusted for the initial fungal burden. The population pharmacokinetics of DAmB are surprisingly consistent. The time to sterilization of the bloodstream may be a useful pharmacodynamic endpoint for future studies. (This study has been registered at the ISRCTN registry under no. ISRCTN59144167.).

Black Molds and Melanized Yeasts Pathogenic to Humans

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.

The spectrum of fungi that infects humans

Few among the millions of fungal species fulfill four basic conditions necessary to infect humans: high temperature tolerance, ability to invade the human host, lysis and absorption of human tissue, and resistance to the human immune system. In previously healthy individuals, invasive fungal disease is rare because animals' sophisticated immune systems evolved in constant response to fungal challenges. In contrast, fungal diseases occur frequently in immunocompromised patients. Paradoxically, successes of modern medicine have put increasing numbers of patients at risk for invasive fungal infections. Uncontrolled HIV infection additionally makes millions vulnerable to lethal fungal diseases. A concerted scientific and social effort is needed to meet these challenges.

AIDS-related mycoses: the way forward

The contribution of fungal infections to the morbidity and mortality of HIV-infected individuals is largely unrecognized. A recent meeting highlighted several priorities that need to be urgently addressed, including improved epidemiological surveillance, increased availability of existing diagnostics and drugs, more training in the field of medical mycology, and better funding for research and provision of treatment, particularly in developing countries.

Cryptococcus neoformans phospholipase B1 activates host cell Rac1 for traversal across the blood-brain barrier

Cryptococcus neoformans penetration into the central nervous system (CNS) requires traversal of the blood-brain barrier that is composed of a single layer of human brain microvascular endothelial cells (HBMEC), but the underlying mechanisms of C. neoformans traversal remain incompletely understood. C. neoformans transcytosis of HBMEC monolayer involves rearrangements of the host cell actin cytoskeleton and small GTP-binding Rho family proteins such as Rac1 are shown to regulate host cell actin cytoskeleton. We, therefore, examined whether C. neoformans traversal of the blood-brain barrier involves host Rac1. While the levels of activated Rac1 (GTP-Rac1) in HBMEC increased significantly upon incubation with C. neoformans strains, pharmacological inhibition and down-modulation of Rac1 significantly decreased C. neoformans transcytosis of HBMEC monolayer. Also, Rac1 inhibition was efficient in preventing C. neoformans penetration into the brain. In addition, C. neoformans phospholipase B1 (Plb1) was shown to contribute to activating host cell Rac1, andSTAT3 was observed to associate with GTP-Rac1 in HBMEC that were incubated with C. neoformans strain but not with its Δplb1 mutant. These findings demonstrate for the first time that C. neoformans Plb1 aids fungal traversal across the blood-brain barrier by activating host cell Rac1 and its association with STAT3, and suggest that pharmacological intervention of host-microbial interaction contributing to traversal of the blood-brain barrier may prevent C. neoformans penetration into the brain.

Invasive mould infections: a multi-disciplinary update

Systemic fungal infections remain a significant cause of mortality in neutropenic and immunocompromised patients, despite advances in their diagnosis and treatment. The incidence of such infections is rising due to the use of intensive chemotherapy regimens in patients with solid tumours or haematological cancers, the increasing numbers of allogeneic haematopoietic stem cell and solid organ transplants, and the use of potent immunosuppressive therapy in patients with autoimmune disorders. In addition, the epidemiology of systemic fungal infections is changing, with atypical species such as Aspergillus terreus and zygomycetes becoming more common. Treatment has traditionally focused on empirical therapy, but targeted pre-emptive therapy in high-risk patients and prophylactic antifungal treatment are increasingly being adopted. New treatments, including lipid formulations of amphotericin B, second-generation broad-spectrum azoles, and echinocandins, offer effective antifungal activity with improved tolerability compared with older agents; the potential impact of these treatments is reflected in their inclusion in current treatment and prophylaxis guidelines. New treatment strategies, such as aerosolized lipid formulations of amphotericin B, may also reduce the burden of mortality associated with systemic fungal infections. The challenge is to identify ways of coupling potentially effective treatments with early and reliable identification of patients at highest risk of infection.

Immune reconstitution syndrome in a patient with disseminated histoplasmosis and steroid taper: maintaining the perfect balance

Immune reconstitution syndrome (IRS) is an increasingly common condition that has been described in immunosuppressed individuals once immune function is restored. In this case, we describe a patient who had a renal transplant and subsequently developed pulmonary histoplasmosis. His course was also complicated by the development of a clinical syndrome that was originally attributed to thrombocytopenic thrombotic purpura (TTP). When he did not improve with plasmapheresis and high dose prednisone, a bone marrow biopsy revealed disseminated histoplasmosis and administration of prednisone was rapidly tapered. While on 5 mg of prednisone, he developed an inflammatory syndrome characterised by haemoptysis and respiratory distress, full work-up with pathology was consistent with immune reconstitution syndrome. Treatment for IRS consists of continuing treatment for the underlying infection and consideration of administering anti-inflammatory medication for supportive care. This syndrome should be considered in patients who develop worsening inflammatory symptoms while receiving appropriate treatment for their fungal infection in the setting of restoration of immune function.

Cost-effectiveness of posaconazole versus fluconazole or itraconazole in the prevention of invasive fungal infections among neutropenic patients in the United States

OBJECTIVES

Clinical trial data indicate that posaconazole is superior to fluconazole (FLU) or itraconazole (ITRA) in preventing invasive fungal infections (IFIs) among neutropenic patients. Our objective was to assess the cost-effectiveness of posaconazole versus FLU or ITRA for prevention of IFIs among neutropenic patients.

METHODS

We used modeling techniques to assess the cost-effectiveness of posaconazole versus FLU or ITRA in the prevention of IFIs among patients with acute myelogenous leukemia (AML) or myelodysplastic syndromes (MDS) and chemotherapy-induced neutropenia. The probabilities of experiencing an IFI, IFI-related death, and death from other causes over 100 days of follow-up were estimated from clinical trial data. Long-term mortality, drug costs, and IFI treatment costs were obtained from secondary sources.

RESULTS

Posaconazole is associated with fewer IFIs per patient (0.05 vs. 0.11) relative to FLU or ITRA over 100 days of follow-up, and lower discounted costs ($3900 vs. $4500) and increased life-years (2.50 vs. 2.43 discounted) over a lifetime horizon. Results from a probabilistic sensitivity analysis indicate that there is a 73% probability that posaconazole is cost saving versus FLU or ITRA and a 96% probability that the incremental cost-effectiveness ratio for posaconazole is at or below $50,000 per life-year saved.

CONCLUSIONS

We conclude that posaconazole is very likely to be a cost-effective alternative to FLU or ITRA in the prevention of IFIs among neutropenic patients with AML and MDS, and may result in cost savings.

Posaconazole vs. fluconazole or itraconazole prophylaxis in patients with neutropenia

BACKGROUND

Patients with neutropenia resulting from chemotherapy for acute myelogenous leukemia or the myelodysplastic syndrome are at high risk for difficult-to-treat and often fatal invasive fungal infections.

METHODS

In this randomized, multicenter study involving evaluators who were unaware of treatment assignments, we compared the efficacy and safety of posaconazole with those of fluconazole or itraconazole as prophylaxis for patients with prolonged neutropenia. Patients received prophylaxis with each cycle of chemotherapy until recovery from neutropenia and complete remission, until occurrence of an invasive fungal infection, or for up to 12 weeks, whichever came first. We compared the incidence of proven or probable invasive fungal infections during treatment (the primary end point) between the posaconazole and fluconazole or itraconazole groups; death from any cause and time to death were secondary end points.

RESULTS

A total of 304 patients were randomly assigned to receive posaconazole, and 298 patients were randomly assigned to receive fluconazole (240) or itraconazole (58). Proven or probable invasive fungal infections were reported in 7 patients (2%) in the posaconazole group and 25 patients (8%) in the fluconazole or itraconazole group (absolute reduction in the posaconazole group, -6%; 95% confidence interval, -9.7 to -2.5%; P<0.001), fulfilling statistical criteria for superiority. Significantly fewer patients in the posaconazole group had invasive aspergillosis (2 [1%] vs. 20 [7%], P<0.001). Survival was significantly longer among recipients of posaconazole than among recipients of fluconazole or itraconazole (P=0.04). Serious adverse events possibly or probably related to treatment were reported by 19 patients (6%) in the posaconazole group and 6 patients (2%) in the fluconazole or itraconazole group (P=0.01). The most common treatment-related adverse events in both groups were gastrointestinal tract disturbances.

CONCLUSIONS

In patients undergoing chemotherapy for acute myelogenous leukemia or the myelodysplastic syndrome, posaconazole prevented invasive fungal infections more effectively than did either fluconazole or itraconazole and improved overall survival. There were more serious adverse events possibly or probably related to treatment in the posaconazole group. (ClinicalTrials.gov number, NCT00044486 [ClinicalTrials.gov].).

Phase I evaluation of the safety and pharmacokinetics of murine-derived anticryptococcal antibody 18B7 in subjects with treated cryptococcal meningitis

A promising approach to improving outcomes in patients with cryptococcal meningitis is to use adjunctive passive immunotherapy with a monoclonal antibody (MAb) directed against the capsular polysaccharide of Cryptococcus neoformans. This is the first application of MAb therapy for the treatment of a fungal disease in humans. We determined the safety and maximum tolerated dose of the murine anticryptococcal MAb 18B7 in a phase I dose-escalation study. The subjects were human immunodeficiency virus-infected patients who had been successfully treated for cryptococcal meningitis. Six dosing cohorts received MAb 18B7 at 0.01 to 2 mg/kg of body weight as a single infusion. Three patients each received 0.01, 0.05, 0.2, and 0.5 mg of MAb 18B7 per kg without significant adverse events. Four of the subjects who received the 1-mg/kg dose had mild study drug-associated toxicity, including transient nausea, vomiting, back pain, and urticarial rash. Two of the subjects who received 2 mg/kg developed drug-associated mild to moderate nausea, vomiting, chills, and myalgias. One of the subjects who received 2 mg/kg developed intracranial hypertension 10 weeks after MAb 18B7 administration. Serum cryptococcal antigen titers in the cohorts receiving doses of 1 and 2 mg/kg declined by a median of twofold at 1 week and a median of threefold at 2 weeks postinfusion, but the titers subsequently returned toward the baseline values by week 12. The half-life of MAb 18B7 in serum was approximately 53 h, while the MAb was undetectable in the cerebrospinal fluid of all patients. These data support the continued investigation of MAb 18B7 at a maximum single dose of 1.0 mg/kg.

Candida endocarditis: contemporary cases from the International Collaboration of Infectious Endocarditis Merged Database (ICE-mD)

Candida infective endocarditis (IE) is increasingly common, yet most reports have been single-center reviews. We evaluated 16 patients with Candida IE nested within a cohort of 2,022 patients with IE. Prosthetic valve IE was more common in patients with Candida (50% vs 17%); mortality was 37% for patients with Candida.

Native valve endocarditis due to Candida glabrata treated without valvular replacement: a potential role for caspofungin in the induction and maintenance treatment

Conventional antifungal therapy for fungal endocarditis has been associated with a poor cure rate. Therefore, combined medical and surgical therapy has been recommended. However, new potent antifungal agents, such as echinocandins, could increase the medical options and, in some cases, avoid the need for surgery. We report a case of Candida endocarditis treated successfully without valve replacement with intravenous liposomal amphotericin B (total dose, 4 g) and intravenous caspofungin (a 100-mg loading dose followed by 50 mg per day for 8 weeks) as induction therapy and intravenous caspofungin (100 mg 3 times per week for 12 weeks) as maintenance therapy.

Global distribution and outcomes for Candida species causing invasive candidiasis: results from an international randomized double-blind study of caspofungin versus amphotericin B for the treatment of invasive candidiasis

In a randomized study, caspofungin was compared with amphotericin B for the treatment of invasive candidiasis in a total of 239 adults from 56 sites in 20 countries. This study provided a unique opportunity to assess the frequency and outcome of invasive candidiasis caused by different Candida species worldwide, and the results are presented here. Efficacy was primarily assessed at the end of intravenous therapy using a modified intent-to-treat (MITT) analysis. This analysis was performed on 224 of the 239 patients enrolled in the study. Attempts were made to collect baseline Candida isolates from all patients for species identification at a central laboratory. Yeasts were identified to the species level using two commercial systems and microscopic examination. Viable baseline isolates were recovered from 210 of the 224 (94%) patients included in the MITT analysis. Candida albicans was the most frequently isolated species in all regions and was responsible for 45% of cases overall. Nevertheless, the majority of cases of infection were caused by non- albicans Candida species. In the USA and Canada, Candida glabrata was the second most commonly isolated pathogen (18%). In contrast, Candida parapsilosis and Candida tropicalis accounted for 55% of cases in Latin America. Outcomes were comparable for patients treated with caspofungin (74% overall; 64% and 80% for infections due to Candida albicans and non- albicans species) and amphotericin B (62% overall; 58% and 68% for infections due to Candida albicans and non- albicans species), and were generally similar across continents. The distribution of Candida species isolated from patients enrolled in a clinical trial may not be representative of pathogens causing invasive candidiasis in the general population. Nevertheless, our findings may affect the regional choice of empirical antifungal therapy for seriously ill patients with suspected or documented invasive candidiasis since different Candida species have varying susceptibility to conventional antifungal drugs.

Comparison of caspofungin and amphotericin B for invasive candidiasis

BACKGROUND

Caspofungin is an echinocandin agent with fungicidal activity against candida species. We performed a double-blind trial to compare caspofungin with amphotericin B deoxycholate for the primary treatment of invasive candidiasis.

METHODS

We enrolled patients who had clinical evidence of infection and a positive culture for candida species from blood or another site. Patients were stratified according to the severity of disease, as indicated by the Acute Physiology and Chronic Health Evaluation (APACHE II) score, and the presence or absence of neutropenia and were randomly assigned to receive either caspofungin or amphotericin B. The study was designed to compare the efficacy of caspofungin with that of amphotericin B in patients with invasive candidiasis and in a subgroup with candidemia.

RESULTS

Of the 239 patients enrolled, 224 were included in the modified intention-to-treat analysis. Base-line characteristics, including the percentage of patients with neutropenia and the mean APACHE II score, were similar in the two treatment groups. A modified intention-to-treat analysis showed that the efficacy of caspofungin was similar to that of amphotericin B, with successful outcomes in 73.4 percent of the patients treated with caspofungin and in 61.7 percent of those treated with amphotericin B (difference after adjustment for APACHE II score and neutropenic status, 12.7 percentage points; 95.6 percent confidence interval, -0.7 to 26.0). An analysis of patients who met prespecified criteria for evaluation showed that caspofungin was superior, with a favorable response in 80.7 percent of patients, as compared with 64.9 percent of those who received amphotericin B (difference, 15.4 percentage points; 95.6 percent confidence interval, 1.1 to 29.7). Caspofungin was as effective as amphotericin B in patients who had candidemia, with a favorable response in 71.7 percent and 62.8 percent of patients, respectively (difference, 10.0 percentage points; 95.0 percent confidence interval, -4.5 to 24.5). There were significantly fewer drug-related adverse events in the caspofungin group than in the amphotericin B group.

CONCLUSIONS

Caspofungin is at least as effective as amphotericin B for the treatment of invasive candidiasis and, more specifically, candidemia.

New antifungal agents

Treatment of fungal infections is an area of increasing concern. This is because of the complexity of underlying illness in affected patients as well as the limited number of antifungal agents available for use. Current strategies focus on prevention of these infections in patients at high risk; however, this has the potential to lead to the emergence of clinically resistant pathogens and superinfections in these patient populations. Future efforts need to focus on earlier diagnosis and more targeted prophylaxis strategies to limit unnecessary use of these potentially toxic pharmaceuticals. Of equal importance is the development of new therapeutic options that provide viable alternatives for practitioners as well as optimal administration of currently available agents. Recent work in this area has yielded a handful of new agents that provide the first step in improving efficacy in these severely immunosuppressed patients, but outcomes still remain suboptimal for many patients suffering from severe fungal infections and/or serious underlying diseases. Clinical antifungal drug resistance must be controlled by improving a series of antifungal therapeutic strategies.

Voriconazole compared with liposomal amphotericin B for empirical antifungal therapy in patients with neutropenia and persistent fever

BACKGROUND

Patients with neutropenia and persistent fever are often treated empirically with amphotericin B or liposomal amphotericin B to prevent invasive fungal infections. Antifungal triazoles offer a potentially safer and effective alternative.

METHODS

In a randomized, international, multicenter trial, we compared voriconazole, a new second-generation triazole, with liposomal amphotericin B for empirical antifungal therapy.

RESULTS

A total of 837 patients (415 assigned to voriconazole and 422 to liposomal amphotericin B) were evaluated for success of treatment. The overall success rates were 26.0 percent with voriconazole and 30.6 percent with liposomal amphotericin B (95 percent confidence interval for the difference, -10.6 to 1.6 percentage points); these rates were independent of the administration of antifungal prophylaxis or the use of colony-stimulating factors. There were fewer documented breakthrough fungal infections in patients treated with voriconazole than in those treated with liposomal amphotericin B (8 [1.9 percent] vs. 21 [5.0 percent], P=0.02). The voriconazole group had fewer cases of severe infusion-related reactions (P<0.01) and of nephrotoxicity (P<0.001). The incidence of hepatotoxicity was similar in the two groups. Patients receiving voriconazole had more episodes of transient visual changes than those receiving liposomal amphotericin B (22 percent vs. 1 percent, P<0.001) and more hallucinations (4.3 percent vs. 0.5 percent, P<0.001). Parenteral voriconazole was changed to the oral formulation in 22 percent of the voriconazole group, with a reduction in the mean duration of hospitalization by one day in all patients (P=0.17) but by two days in patients at high risk (P=0.03).

CONCLUSIONS

Voriconazole is a suitable alternative to amphotericin B preparations for empirical antifungal therapy in patients with neutropenia and persistent fever.

Calcineurin is required for virulence of Cryptococcus neoformans

Cyclosporin A (CsA) and FK506 are antimicrobial, immunosuppressive natural products that inhibit signal transduction. In T cells and Saccharomyces cerevisiae, CsA and FK506 bind to the immunophilins cyclophilin A and FKBP12 and the resulting complexes inhibit the Ca2+-regulated protein phosphatase calcineurin. We find that growth of the opportunistic fungal pathogen Cryptococcus neoformans is sensitive to CsA and FK506 at 37 degrees C but not at 24 degrees C, suggesting that CsA and FK506 inhibit a protein required for C. neoformans growth at elevated temperature. Genetic evidence supports a model in which immunophilin-drug complexes inhibit calcineurin to prevent growth at 37 degrees C. The gene encoding the C. neoformans calcineurin A catalytic subunit was cloned and disrupted by homologous recombination. Calcineurin mutant strains are viable but do not survive in vitro conditions that mimic the host environment (elevated temperature, 5% CO2 or alkaline pH) and are no longer pathogenic in an animal model of cryptococcal meningitis. Introduction of the wild-type calcineurin A gene complemented these growth defects and restored virulence. Our findings demonstrate that calcineurin is required for C. neoformans virulence and may define signal transduction elements required for fungal pathogenesis that could be targets for therapeutic intervention.

The immunosuppressant FK506 and its nonimmunosuppressive analog L-685,818 are toxic to Cryptococcus neoformans by inhibition of a common target protein

The immunosuppressant FK506 (tacrolimus) is an antifungal natural product macrolide that suppresses the immune system by blocking T-cell activation. In complex with the intracellular protein FKBP12, FK506 inhibits calcineurin, a Ca(2+)-calmodulin-dependent serine-threonine protein phosphatase. We recently reported that growth of the opportunistic fungal pathogen Cryptococcus neoformans is resistant to FK506 at 24 degrees C but sensitive at 37 degrees C and that calcineurin, the target of FKBP12-FK506, is required for growth at 37 degrees C in vitro and pathogenicity in vivo. These findings identify calcineurin as a potential antifungal drug target. In previous studies the calcineurin inhibitor cyclosporin A (CsA) was effective against murine pulmonary infections but exacerbated cryptococcal meningitis in rabbits and mice, likely because CsA does not cross the blood-brain barrier. Although we find that FK506 penetrates the CNS, FK506 also exacerbates cryptococcal meningitis in rabbits. Thus, FK506 immunosuppression outweighs antifungal action in vivo. Like FK506, the nonimmunosuppressive FK506 analog L-685,818 is toxic to C. neoformans in vitro at 37 degrees C but not at 24 degrees C, and FK506-resistant mutants are resistant to L-685,818, indicating a similar mechanism of action. Fluconazole-resistant C. neoformans clinical isolates were also found to be susceptible to both FK506 and L-685,818. Our findings identify calcineurin as a novel antifungal drug target and suggest the nonimmunosuppressive FK506 analog L-685,818 or other congeners warrant further consideration as antifungal drugs for C. neoformans.

The significance of microbial cultures of the hematopoietic support for patients receiving high-dose chemotherapy

The use of hematopoietic support for patients receiving high-dose chemotherapy has increased over the past 10 years. Various quality controls are performed on the hematopoietic cells, including microbiologic cultures. There is considerable expense associated with the serial cultures performed at different times during the collection, processing, and use of the cells. We reviewed all the microbiologic cultures performed on bone marrow harvests and leukaphereses over a 17 month period. Of the 227 bone marrow harvests, 16 cultures were positive, but only 3 (1.3%) were repeat positives with the same organism after processing or at the time of reinfusion. Of the 560 leukaphereses, 4 (0.7%) were cultured positive at the time of collection and reinfusion. Two patients were bacteremic with gram-negative bacilli at the time of leukaphereses despite being asymptomatic, and these were the only two products that had to be collected again. No patient suffered an adverse clinical result after receiving culture-positive cells. Bone marrow and peripheral blood progenitor cells can be safely collected, and a culture after processing is adequate to ensure the safety of the product.

Soft-tissue fungal infections: surgical management of 12 immunocompromised patients

Isolated fungal soft-tissue infections are uncommon but may cause severe morbidity or mortality among transplant recipients and other immunosuppressed patients. Twelve immunocompromised patients illustrating three patterns of infection were treated recently at the Duke University Medical Center. These groups comprised (I) locally aggressive infections, (II) indolent infections, and (III) cutaneous manifestations of systemic infection. Patient diagnoses included organ transplant, leukemia, prematurity, chronic obstructive pulmonary disease, and rheumatoid arthritis. Time from immunosuppression to biopsy ranged from 5.5 to 31 weeks. Organisms included Aspergillus, Rhizopus, Fusarium, Paecilomyces, Exophiala, and Curvularia. Patients presented with necrotic ulcerations or nodules. Surgical treatment ranged from radical debridement to excisional biopsy to none. Antifungal chemotherapy also was employed in some cases. The mortality rate was 33 percent, two patients dying without evidence of fungal infection. Six of the eight survivors cleared their infections. Necrotic skin lesions with surrounding erythema in this population call for prompt examination, biopsy, and culture. Group I lesions mandate radical excision with rapid intraoperative microscopic control and systemic antifungal medication. Group II requires surgical control with or without antifungal therapy. Group III requires systemic antifungal therapy for metastatic infection. In our opinion, treatment of fungal soft-tissue infection should be tailored to infection type and requires a team approach of surgeon and expert infectious disease consultation.

Alopecia associated with fluconazole therapy

OBJECTIVE

To describe the association between fluconazole and reversible alopecia.

DESIGN

A retrospective survey of 1) patients enrolled in NIAID Mycoses Study Group (MSG) protocols involving the long-term use of fluconazole for treatment of endemic mycoses and 2) patients treated with fluconazole outside of a protocol setting but by the MSG investigators who were MSG members.

SETTING

26 MSG sites in the United States.

PATIENTS

33 patients with various deep and superficial mycoses who developed alopecia while receiving fluconazole.

RESULTS

11 of 26 investigators reported a total of 33 patients with substantial alopecia related to fluconazole therapy. Underlying mycoses included blastomycosis, sporotrichosis, histoplasmosis, cryptococcosis, coccidioidomycosis, and mucosal candidiasis. In separate MSG studies, 17 of 136 (12.5%) and 8 of 40 (20%) patients had substantial reversible alopecia associated with fluconazole therapy. Eight patients who were not in the protocol had similar adverse effects. Twenty-nine of 33 patients (88%) received at least 400 mg of fluconazole daily for a mean of 7.1 months. Alopecia developed a median of 3 months after initiation of fluconazole therapy and involved the scalp in all patients. Other sites were involved in about one third of patients. Three patients required wigs because of extensive hair loss. Alopecia resolved within 6 months of discontinuation of fluconazole therapy or reduction of the daily dose by at least 50%.

CONCLUSIONS

Alopecia appears to be a common adverse event associated with higher-dose (400 mg/d) fluconazole given for 2 months or longer. This effect may be severe but is reversed by discontinuing fluconazole therapy or substantially reducing the daily dose.

Management of injuries caused by Cryptococcus neoformans--contaminated needles

This report describes four skin-puncture accidents with needles that were heavily contaminated with Cryptococcus neoformans. In one accident, delayed administration of antifungal drugs resulted in a granuloma of the finger. In the other three accidents, no skin infection followed immediate prophylaxis with oral fluconazole. Our experience suggests that early therapy with fluconazole is a reasonable means of managing skin injuries caused by instruments contaminated with viable C. neoformans.

Sequential prophylactic oral and empiric once-daily parenteral antibiotics for neutropenia and fever after high-dose chemotherapy and autologous bone marrow support

PURPOSE

We studied the effectiveness of prophylactic oral ciprofloxacin and rifampin on fever prevention in patients undergoing autologous bone marrow transplantation (ABMT) for breast cancer. Furthermore, we evaluated the toxicity and efficacy of empiric once-daily vancomycin and tobramycin for febrile neutropenia.

PATIENTS AND METHODS

Ninety-nine assessable women received prophylactic ciprofloxacin and rifampin after high-dose chemotherapy (HDC) for advanced or high-risk primary breast cancer supported with either bone marrow and peripheral-blood progenitor cells (PBPCs) or bone marrow purged with chemotherapy and monoclonal antibodies. Neutropenic fever was treated with empiric once-daily vancomycin and tobramycin. Patients were compared with historic controls treated with the identical HDC and bone marrow support regimen.

RESULTS

In patients treated with bone marrow and PBPCs, the incidence of fever during neutropenia was reduced by ciprofloxacin and rifampin from 98% to 57%. Documented infections were reduced from 42% to 13% (P < .01) and bacteremia from 18% to 0% (P < .001). In purged bone marrow recipients, the overall infection rate decreased from 74% to 17% (P < .001), and bacteremia from 29% to 7%. (P = .02). No patient developed breakthrough bacteremia or sepsis syndrome while on study. Serum creatinine level greater than 1.8 g/dL was noted in 7% of controls and 10% of study patients. Increased ototoxicity was not encountered with the higher peak concentrations of vancomycin and tobramycin.

CONCLUSION

The therapeutic strategy of ciprofloxacin and rifampin followed by once-daily vancomycin and tobramycin markedly reduced the incidence of infection and virtually eliminated bacteremia in both purged and nonpurged bone marrow recipients. Once-daily vancomycin and tobramycin was safe and effective and, because of the ease of use, facilitates outpatient management of ABMT patients.

Intervertebral diskitis due to Candida tropicalis

This report describes a case of Candida tropicalis intervertebral diskitis successfully treated with a brief course of amphotericin B followed by a longer course of ketoconazole. Candida tropicalis is an increasingly frequent pathogen in immunocompromised patients, and infection can become manifest weeks or months after an episode of neutropenia has resolved. The excellent response we observed in this patient adds to a growing body of clinical experience testifying to the effectiveness of ketoconazole in treating certain deep-seated candidal infection.