Validating genetic variants in innate immunity linked to infectious events in acute myeloid leukemia post-induction chemotherapy.

Infectious events, such as sepsis and invasive fungal disease (IFD), pose significant risks in patients with acute myeloid leukemia (AML). Previous studies, including our own, have suggested a potential role of single nucleotide polymorphisms (SNPs) within the innate immune system in influencing individual infection susceptibility. However, many of these associations lack validation in independent cohorts. This study sought to validate the impact of 11 candidate SNPs across 6 genes (TLR2, TLR4, Dectin-1, DC-SIGN, PTX3, L-Ficolin) in an independent cohort of patients. Two cohorts with newly diagnosed AML patients receiving intensive induction chemotherapy were analyzed: a stratification cohort comprising 186 patients and a validation cohort consisting of 138 patients. Multiple SNPs in each cohort were found to be associated to infectious complications, notably the DC-SIGN SNP rs4804800 demonstrated a significant association with sepsis in both cohorts. SNPs within the PTX3 and Dectin-1 genes were linked to IFD development in one cohort each. This study represents the first validation study of candidate genes associated with infectious events in AML patients after intensive induction chemotherapy. Identifying genetic predispositions to infections could significantly impact the management of antimicrobial prophylaxis and treatment in AML patients.

Recipient and donor PTX3 rs2305619 polymorphisms increase the susceptibility to invasive fungal disease following haploidentical stem cell transplantation: a prospective study.

BACKGROUND: Invasive fungal disease (IFD) is a severe complication after haploidentical stem cell transplantation (haplo-HSCT) and has a poor prognosis. It has been shown that genetic polymorphism may be one possible reason for the increased risk of IFD. This study aimed to assess the role of genetic polymorphism in the level of susceptibility to IFD after haplo-HSCT. METHODS: In this study, we prospectively enrolled 251 patients who received haplo-HSCT at the Peking University Institute of Hematology from 2016 to 2018. Forty-three single nucleotide polymorphisms (SNPs) of the genomic DNA were genotyped in blood samples from both recipient and donor. RESULTS: Twenty-two patients (8.8%) were diagnosed with proven or probable IFD. The independent risk factors for IFD were grades 3-4 acute graft-versus-host disease, cytomegalovirus reactivation, and recipient and donor rs2305619 (PTX3) (P < 0.05) in multivariate analysis. Meanwhile, we combined the variables to develop the IFD risk scoring system and stratified patients into low- (0-2) and high-risk (3-4) groups. The 30-day and 100-day cumulative incidence of IFD in the low- and high-risk groups were 2.1% and 10.2%, 4.2% and 20.3%, respectively (P = 0.015). CONCLUSIONS: PTX3 rs2305619 polymorphism increase the susceptibility of IFD after haplo-HSCT in the Chinese Han population, and the IFD scoring system could be useful in risk stratification for IFD after HSCT.

Pattern recognition receptors in fungal immunity.

Over the last decade, invasive fungal infections have emerged as a growing threat to human health worldwide and novel treatment strategies are urgently needed. In this context, investigations into host-pathogen interactions represent an important and promising field of research. Antigen presenting cells such as macrophages and dendritic cells are strategically located at the frontline of defence against potential invaders. Importantly, these cells express germline encoded pattern recognition receptors (PRRs), which sense conserved entities from pathogens and orchestrate innate immune responses. Herein, we review the latest findings regarding the biology and functions of the different classes of PRRs involved in pathogenic fungal recognition. We also discuss recent literature on PRR collaboration/crosstalk and the mechanisms involved in inhibiting/regulating PRR signalling. Finally, we discuss how the accumulated knowledge on PRR biology, especially Dectin-1, has been used for the design of new immunotherapies against fungal infections.

Inherited CARD9 Deficiency in a Child with Invasive Disease Due to Exophiala dermatitidis and Two Older but Asymptomatic Siblings.

PURPOSE: Autosomal recessive CARD9 deficiency predisposes patients to invasive fungal disease. Candida and Trichophyton species are major causes of fungal disease in these patients. Other CARD9-deficient patients display invasive diseases caused by other fungi, such as Exophiala spp. The clinical penetrance of CARD9 deficiency regarding fungal disease is surprisingly not complete until adulthood, though the age remains unclear. Moreover, the immunological features of genetically confirmed yet asymptomatic individuals with CARD9 deficiency have not been reported. METHODS: Identification of CARD9 mutations by gene panel sequencing and characterization of the cellular phenotype by quantitative PCR, immunoblot, luciferase reporter, and cytometric bead array assays were performed. RESULTS: Gene panel sequencing identified compound heterozygous CARD9 variants, c.1118G>C (p.R373P) and c.586A>G (p.K196E), in a 4-year-old patient with multiple cerebral lesions and systemic lymphadenopathy due to Exophiala dermatitidis. The p.R373P is a known disease-causing variant, whereas the p.K196E is a private variant. Although the patient's siblings, a 10-year-old brother and an 8-year-old sister, were also compound heterozygous, they have been asymptomatic to date. Normal CARD9 mRNA and protein expression were found in the patient's CD14+ monocytes. However, these cells exhibited markedly impaired pro-inflammatory cytokine production in response to fungal stimulation. Monocytes from both asymptomatic siblings displayed the same cellular phenotype. CONCLUSIONS: CARD9 deficiency should be considered in previously healthy patients with invasive Exophiala dermatitidis disease. Asymptomatic relatives of all ages should be tested for CARD9 deficiency. Detecting cellular defects in asymptomatic individuals is useful for diagnosing CARD9 deficiency.

Optimization of voriconazole therapy for treatment of invasive aspergillosis: Pharmacogenomics and inflammatory status need to be evaluated.

AIMS: Cytochrome 2C19 genotype-directed dosing of voriconazole (VRC) reduces the incidence of insufficient VRC trough concentrations (Cmin ) but does not account for CYP3A polymorphisms, also involved in VRC metabolism. This prospective observational study aimed to evaluate the utility of a genetic score combining CYP2C19 and CYP3A genotypes to predict insufficient initial VRC Cmin (<1 mg/L). METHODS: The genetic score was determined in hematological patients treated with VRC. The higher the genetic score, the faster the metabolism of the patient. The impact of the genetic score was evaluated considering initial VRC Cmin and all VRC Cmin (n = 159) determined during longitudinal therapeutic drug monitoring. RESULTS: Forty-three patients were included, of whom 41 received VRC for curative indication. Thirty-six patients had a genetic score ≥2, of whom 11 had an initial insufficient VRC Cmin . A genetic score ≥2 had a positive predictive value of 0.31 for having an initial insufficient VRC Cmin and initial VRC Cmin was not associated with the genetic score. The lack of association between the genetic score and VRC Cmin may be related to the inflammatory status of the patients (C-reactive protein [CRP] levels: median [Q1-Q3]: 43.0 [11.0-110.0] mg/L), as multivariate analysis performed on all VRC Cmin identified CRP as an independent determinant of the VRC Cmin adjusted for dose (P < .0001). CONCLUSION: The combined genetic score did not predict low VRC exposure in patients with inflammation, which is frequent in patients with invasive fungal infections. Strategies for the individualization of VRC dose should integrate the inflammatory status of patients in addition to pharmacogenetic variants.

The influence of CYP2C19 polymorphisms on voriconazole trough concentrations: Systematic review and meta-analysis.

BACKGROUND: Voriconazole primary metabolism is catalysed by CYP2C19. A large variability of trough concentrations in patients with invasive fungal infection treated with voriconazole has been observed in clinical practice. It remains controversial whether the CYP2C19 polymorphisms are responsible for voriconazole metabolism in the individual variation. OBJECTIVES: The primary aim of this study was to assess the effect of CYP2C19 polymorphisms on voriconazole trough concentrations. METHODS: Following a systematic literature review, we performed a meta-analysis for mean differences (MD) of voriconazole trough concentrations (Cmin ), voriconazole dosage adjusted trough concentrations (Cmin /D) and for risk ratio (RR) of the proportion of patients in the target therapeutic range between pairwise comparisons of CYP2C19 phenotypes. RESULTS: Compared with normal metabolisers (NMs), intermediate metabolisers (IMs) (MD: 0.82, 95% CI: 0.57 to 1.07, I2  = 44%, p < .00001) or poor metabolisers (PMs) (MD: 1.59, 95% CI: 1.14 to 2.05, I2  = 46%, p < .00001) had significantly higher voriconazole Cmin (µg·ml-1 ), while rapid metabolisers (RMs) had significantly lower voriconazole Cmin (MD: -0,87, 95% CI: -1.35 to -0.38, I2  = 0%, p = .0004). In addition, IMs had significantly lower Cmin than PMs (MD: -0.59, 95% CI: -0.97 to -0.20, I2  = 22%, p = .003). Similarly, the Cmin /D (µg·kg·ml-1 ·mg-1 ) was significantly higher in IMs (MD: 0.13, 95% CI: 0.05 to 0.22, I2  = 0%, p = .002) and PMs (MD: 0.20, 95% CI: 0.07 to 0.34, I2  = 0%, p = .003) than that in NMs, and also, IMs had significantly lower Cmin /D than PMs (MD: -0.11, 95% CI: -0.14 to -0.08, I2  = 0%, p < .00001). Furthermore, PMs had a significantly higher proportion of the target therapeutic range than NMs (RR: 1.34, 95% CI: 1.09 to 1.64, I2  = 50%, p = .005). CONCLUSIONS: Compared to NMs, IMs and PMs had higher voriconazole trough concentrations, especially in Asians, while RMs had lower voriconazole trough concentrations. In addition, PMs had a higher proportion of the target therapeutic range than NMs, especially in Asians. CYP2C19 genotyping is expected to be used to preemptively guide the individualisation of voriconazole in clinical practice.

Invasive Saprochaete capitata Infection in a Patient with Autosomal Recessive CARD9 Deficiency and a Review of the Literature.

PURPOSE: Autosomal recessive (AR) CARD9 deficiency is an inherited immune disorder which results in impaired innate immunity against various fungi. Superficial and invasive fungal infections, mainly caused by Candida or Trichophyton species, are the hallmark of CARD9 deficiency. Together with the increasing number of CARD9-deficient patients reported, different pathogenic fungal species have been described such as Phialophora, Exophiala, Corynespora, Aureobasidium, and Ochroconis. Saprochaete capitata is an opportunistic infectious agent in immunocompromised patients and is a common cause of invasive fungal disease in patients with hematological malignancies. In this study, we investigated the causative genetic defect in a patient with S. capitata fungal infection which disseminated to lymph nodes and common bile duct. METHODS: The identification of the isolated yeast strain was made by direct microscopic examination and confirmed by internal transcribed spacer (ITS) sequencing. We applied whole exome sequencing to search for the disease-causing mutation. Sanger sequencing was used to validate the mutation in the patient and his parents. RESULTS: S. capitata was isolated from the biopsy specimen as the causative microorganism responsible for the invasive fungal disease in the patient. Whole exome sequencing revealed a homozygous c.883C > T, (p.Q295*) mutation in CARD9, confirmed by Sanger sequencing. CONCLUSIONS: This is the first report of invasive Saprochaete infection associated with autosomal recessive (AR) CARD9 deficiency in the literature and thereby further extends the spectrum of fungal diseases seen in these patients.

Cell-free DNA next-generation sequencing successfully detects infectious pathogens in pediatric oncology and hematopoietic stem cell transplant patients at risk for invasive fungal disease.

BACKGROUND: We sought to determine if next-generation sequencing (NGS) of microbial cell-free DNA (cfDNA) in plasma would detect pathogens in pediatric patients at risk for invasive fungal disease (IFD). PROCEDURES: Pediatric hematology, oncology, and stem cell transplant patients deemed at risk for new IFD had blood samples drawn at three time-points separated by 1-month intervals. The primary outcome measure was detection of fungal pathogens compared to standard clinical testing. Secondary outcomes included identification of other infectious pathogens, relationship to European Organization for Research and Treatment of Cancer's Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases' Mycoses Study Group (EORTC/MSG) guidelines, and assessment of antifungal therapy. RESULTS: NGS identified fungal pathogens in seven of 40 at-risk patients for IFD and results were identical in four of six proven cases, including Aspergillus fumigatus by lung biopsy, Candida albicans by blood or pancreatic pseudocyst cultures, and Rhizopus delemar by skin biopsy. Rhizopus oryzae identified on skin biopsy and A. fumigatus isolated on day 27 of 28 of culture from lung biopsy were not detected by cfDNA NGS, possibly due to lack of bloodstream penetration and questionable pathogenicity, respectively. Numerous DNA viruses were detected in patients with prolonged febrile neutropenia or abnormal imaging. Extended antifungal therapy was used in 73% of patients. Follow-up cfDNA sequencing in patients who were positive at enrollment was negative at 1 and 2 months. CONCLUSIONS: cfDNA NGS detected fungal pathogens from blood confirming its potential to guide treatment decisions in pediatric patients at risk for IFD and limit excessive empiric antifungal use. Future studies are needed to better understand the sensitivity and specificity of this approach.

Predicting Invasive Aspergillosis in Hematology Patients by Combining Clinical and Genetic Risk Factors with Early Diagnostic Biomarkers.

Personalized medicine provides a strategic approach to the management of IA. The incidence of IA in high-risk hematology populations is relatively low (<10%), despite unavoidable Aspergillus exposure in patients with a potentially similar clinical risk. Nonclinical variables, including genetic mutations that increase susceptibility to IA, could explain why only certain patients develop the disease. This study screened for mutations in 322 hematology patients classified according to IA status and developed a predictive model based on genetic risk, established clinical risk factors, and diagnostic biomarkers. Genetic markers were determined by real-time PCR and, with clinical risk factors and Aspergillus PCR results, subjected to multilogistic regression analysis to identify a best-fit model for predicting IA. The probability of IA was calculated, and an optimal threshold was determined. Mutations in dectin-1 (rs7309123) and DC-SIGN (rs11465384 and rs7248637), allogeneic stem cell transplantation, respiratory virus infection, and Aspergillus PCR positivity were all significant risk factors for developing IA and were combined in a predictive model. An optimal threshold requiring three positive factors generated a mean sensitivity/specificity of 70.4%/89.2% and a probability of developing IA of 56.7%. In patients with no risk factors, the probability of developing IA was 2.4%, compared to >79.1% in patients with four or more factors. Using a risk threshold of 50%, preemptive therapy would have been prescribed for 8.4% of the population. This pilot study shows that patients can be stratified according to risk of IA, providing personalized medicine based on strategic evidence for the management of IA. Further studies are required to confirm this approach.

Impact of the CYP2C19 genotype on voriconazole exposure in adults with invasive fungal infections.

OBJECTIVES: Voriconazole, a first-line agent for the treatment of invasive fungal infections (IFIs), is metabolized by CYP2C19. A significant proportion of patients fail to achieve therapeutic trough concentrations with standard weight-based voriconazole dosing, placing them at increased risk for treatment failure, which can be life threatening. We sought to test the association between the CYP2C19 genotype and subtherapeutic voriconazole concentrations in adults with IFIs. PATIENT AND METHODS: Adults receiving weight-based voriconazole dosing for the treatment of IFIs were genotyped for the CYP2C19*2, *3, and *17 polymorphisms, and CYP2C19 metabolizer phenotypes were inferred. Steady-state voriconazole trough plasma concentrations and the prevalence of subtherapeutic troughs (<2 mg/l) were compared between patients with the CYP2C19*17/*17 (ultrarapid metabolizer, UM) or *1/*17 (rapid metabolizer, RM) genotype versus those with other genotypes. Logistic regression, adjusting for clinical factors, was performed to estimate the odds of subtherapeutic concentrations. RESULTS: Of 70 patients included (mean age 52.5±18 years), 39% were RMs or UMs. Compared with patients with the other phenotypes, RMs/UMs had a lower steady-state trough concentration (4.26±2.2 vs. 2.86±2.3, P=0.0093) and a higher prevalence of subtherapeutic troughs (16 vs. 52%, P=0.0028), with an odds ratio of 5.6 (95% confidence interval: 1.64-19.24, P=0.0044). CONCLUSION: Our findings indicate that adults with the CYP2C19 RM or UM phenotype are more likely to have subtherapeutic concentrations with weight-based voriconazole dosing. These results corroborate previous findings in children and support the potential clinical utility of CYP2C19 genotype-guided voriconazole dosing to avoid underexposure in RMs and UMs.

Chronic and Invasive Fungal Infections in a Family with CARD9 Deficiency.

Chronic mucocutaneous or invasive fungal infections are generally the result of primary or secondary immune dysfunction. Patients with autosomal recessive CARD9 mutations are also predisposed to recurrent mucocutaneous and invasive fungal infections with Candida spp., dermatophytes (e.g., Trichophyton spp.) and phaeohyphomycetes (Exophiala spp., Phialophora verrucosa). We study a consanguineous family of Turkish origin in which three members present with distinct clinical phenotypes of chronic mucocutaneous and invasive fungal infections, ranging from chronic mucocutaneous candidiasis (CMC) in one patient, treatment-resistant cutaneous dermatophytosis and deep dermatophytosis in a second patient, to CMC with Candida encephalitis and endocrinopathy in a third patient. Two patients consented to genetic testing and were found to have a previously reported homozygous R70W CARD9 mutation. Circulating IL-17 and IL-22 producing T cells were decreased as was IL-6 and granulocyte/macrophage colony-stimulating factor (GM-CSF) secretion upon stimulation with Candida albicans. Patients with recurrent fungal infections in the absence of known immunodeficiencies should be analyzed for CARD9 gene mutations as the cause of fungal infection predisposition.

Incorporating the Detection of Single Nucleotide Polymorphisms Associated With Invasive Aspergillosis Into the Clinic.

Exposure to fungi is inevitable, yet only a small number of patients with significant clinical risk develop invasive aspergillosis (IA). While timing of exposure in relation to immune status, environmental and occupational factors will influence the probability of developing IA, factors specific to the individual will likely play a role and variation in the host's genetic code associated with the immunological response to fungi have been linked to increased risk of developing IA. Screening for SNPs in genes significantly associated with IA (e.g. Pentraxin-3, Toll-like receptor 4, Dectin-1, DC-SIGN) could form part of the clinical work-up on admission or post allogeneic stem cell transplantation, to complement fungal biomarker screening. Through the combination of clinical and genetic risk with mycological evidence, we are approaching a time when we should be able to accurately predict the risk of IA in the haematology patient, using predictive modelling to stratifying each individual's management. Understanding the host and their immune responses to infection through genomics, transcriptomics and metabolomics/proteomics is critical to achieving how we manage the individual's risk of IA, underpinning personalized medicine. This review will investigate what is known about the genetic risk associated with developing IA, primarily in haematology patients and whether these strategies are ready to be incorporated into routine clinical practice, and if not what are the remaining hurdles to implementation.

Immune defence to invasive fungal infections: A comprehensive review.

The fungal infections are relatively common in humans that can range from common, mild superficial infections to life-threatening invasive infections. Most of the pathogenic fungi are opportunistic that cause disease under immunocompromised conditions such as HIV infection, cancer, chemotherapy, transplantation and immune suppressive drug users. Efficient detection and treatment of high-risk population remain the highest priority to avert most of the deaths. Majority of invasive infections are caused by Candida, Aspergillus and Cryptococcus species. Lack of effective vaccines, standardised diagnostic tools, efficient antifungal drugs and the emergence of drug-resistant species/strains pose a global threat to control Invasive fungal infections (IFI). A better understanding of the host immune response is one of the major approaches to developing new or improved antifungal strategies to control the IFIs. In this review, we have discussed pathogenesis of medically important fungi, fungal interaction with the host through pattern recognition receptors (PRRs) and the interplay of innate and adaptive immune cells in shaping host immunity to IFI. Further, we emphasized the role of memory cells by offering long-term protection in secondary or subsequent infections. Moreover, we depicted the role of unconventional innate-like immune cells in anti-fungal immunity. We also summarize the available information on the current vaccine strategies, genetic susceptibility to fungal infections, recent co-infections studies and the emergence of drug-resistance, a growing trend throughout the world. Finally, we emphasized the steps to be taken for the control of IFIs.

Impact of CYP2C19, CYP3A4, ABCB1, and FMO3 genotypes on plasma voriconazole in Thai patients with invasive fungal infections.

Voriconazole is the first-line antifungal choice in the treatment of invasive fungal infections (IFIs). Single nucleotide polymorphisms (SNPs) in drug-metabolizing and transporter genes may affect voriconazole pharmacokinetics. This study aimed to determine the frequency of the CYP2C19 rs4244285, rs4986893, rs72552267, and rs12248560, CYP3A4 rs4646437, ABCB1 rs1045642, and FMO3 rs2266782 alleles and determine the association between these genetic variants and voriconazole concentrations in Thai patients with invasive fungal infections. The study comprised 177 Thai patients with IFIs in whom seven SNPs in CYP2C19, CYP3A4, ABCB1, and FMO3 were genotyped using TaqMan real-time polymerase chain reaction (RT-PCR) 5´ nuclease assays, and voriconazole plasma concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Of the 177 patients included, 31 were <12 years and 146 were ≥12 years. The CYP2C19 allele frequencies were 0.29 for *2, 0.060 for *3, 0.003 for *6, and 0.008 for *17. The allele frequency of CYP3A4 (rs4646437) was 0.26, ABCB1 (rs1045642) was 0.36, and FMO3 (rs2266782) was 0.16. The median voriconazole dose/weight was significantly lower in patients aged ≥12 years when compared to the patients aged <12 years (P < .001). Patients aged <12 years with CYP2C19*1/*2 exhibited significantly higher median voriconazole plasma concentrations than those with the CYP2C19*1/*1 (P = .038). However, there were no significant differences in median voriconazole plasma concentrations among the CYP2C19 genotypes in the patients aged ≥12 years. There was a lack of association observed among the CYP3A4, ABCB1, and FMO3 genotypes on the plasma voriconazole concentrations in both groups of patients. Our findings indicate that voriconazole plasma concentrations are affected by the CYP2C19*2 allele in patients aged <12 years but not in patients aged ≥12 years.

Development of multiplex real-time PCR for rapid identification and quantitative analysis of Aspergillus species.

The identification of Aspergillus species and azole resistance is highly important for the treatment of invasive aspergillosis (IA), which requires improvements in current fungal diagnostic methods. We aimed to develop multiplex real-time PCR to identify major Aspergillus section and azole resistance. BenA and cyp51A genes were used to design primers, probes, and control DNA for multiplex PCR. Qualitative and quantitative analysis was conducted for 71 Aspergillus and 47 non-Aspergillus isolates. Further, the limit of detection (LOD) and limit of quantitation (LOQ) from hyphae or conidia were determined according to the culture time. Newly developed real-time PCR showed 100% specificity to each Aspergillus section (Fumigati, Nigri, Flavi, and Terrei), without cross-reaction between different sections. In quantitative analysis of sensitivity measurements, LOD and LOQ were 40 fg and 400 fg, respectively. Melting temperature analysis of the cyp51A promoter to identify azole resistance showed temperatures of 83.0 ± 0.3°C and 85.6 ± 0.6°C for susceptible A. fumigatus and resistant isolates with TR34 mutation, respectively. The minimum culture time and fungal colony size required for successful detection were 24 h and 0.4 cm in diameter, respectively. The developed multiplex real-time PCR can identify common Aspergillus sections quantitatively and detect presence of the TR34 mutation. Further, this method shows high sensitivity and specificity, allowing successful detection of early-stage fungal colonies within a day of incubation. These results can provide a template for rapid and accurate diagnosis of IA.

Free circulating mircoRNAs support the diagnosis of invasive aspergillosis in patients with hematologic malignancies and neutropenia.

Fungal infections represent a worrisome complication in hematologic cancer patients and in the absence of disease specific symptoms, it is important to establish new biological indicators, which can be used during mould-active prophylaxis. Recently, miRNAs have appeared as candidate diagnostic and prognostic markers of several diseases. A pilot clinical study was performed to evaluate the diagnostic utility of 14 microRNAs which can be related to invasive fungal infections. Based on our data miR-142-3p, miR-142-5p, miR-26b-5p and miR-21-5p showed significant overexpression (p < 0.005) due to invasive aspergillosis in hemato-oncology patients with profound neutropenia. A tetramiR assay was designed to monitor peripheral blood specimens. Optimal cut-off was estimated by using the median value (fold change 1.1) of the log10 transformed gene expressions. The biomarker panel was evaluated on two independent sample cohorts implementing different antimicrobial prophylactic strategies. The receiver operating characteristic analysis with area under the curve proved to be 0.97. Three miRNAs (miR-142-5p, miR-142-3p, miR-16-5p) showed significant expression alterations in episodes with sepsis. In summary, the tetramiR assay proved to be a promising diagnostic adjunct with sufficient accuracy and sensitivity to trace invasive aspergillosis in hemato-oncology patients.

Correlation of CYP2C19 genotype with plasma voriconazole exposure in South-western Chinese Han patients with invasive fungal infections.

The aim of this study was to investigate the correlation between CYP2C19 genotype and dose-adjusted voriconazole (VCZ) trough concentrations (C0/dose).We analyzed the correlation between CYP2C192(681G>A), CYP2C193(636G>A), and CYP2C1917(-806C>T) genetic polymorphisms and the dose-corrected pre-dose concentration (C0/dose) in 106 South-western Chinese Han patients.The frequencies of variant alleles of CYP2C192, 3, and 17 were 29.7%, 4.25%, and 0.92%. For 49.3% of the VCZ samples, the therapeutic window between 1.5 and 5.5 µg/ml was reached. Following the first dose VCZ measurement, in subsequent samples the proportion of VCZ C0 within the therapeutic window increased, suggesting effective therapeutic drug monitoring (TDM) (P = .001). The VCZ C0 was significantly different (P = .010) between patients with normal metabolism (NMs), intermediate metabolism (IMs), and poor metabolism (PMs). The VZC C0/dose was 12.2 (interquartile range (IQR), 8.33-18.2 µg·ml/kg·day), and 7.68 (IQR, 4.07-16.3 µg·ml/kg·day) in PMs and IMs patients, respectively, which was significantly higher than in NMs phenotype patients (4.68; IQR, 2.51-8.87 µg·ml/kg·day, P = .008 and P = .014).This study demonstrated that the VCZ C0/dose was significantly influenced by the CYP2C19 genotype in South-western Chinese Han patients. In this patient population, more over-exposure was observed in patients with a CYP2C19 genotype associated with poor or intermediate metabolism. CYP2C19 genotype-based dosing combined with TDM will support individualization of VCZ dosing, and potentially will minimize toxicity and maximize therapeutic efficacy.

Dectin-1 rs3901533 and rs7309123 Polymorphisms Increase Susceptibility to Pulmonary Invasive Fungal Disease in Patients with Acute Myeloid Leukemia from a Chinese Han Population.

This study aimed to assess whether genetic variants of dendritic cell-associated C-type lectine-1 (Dectin-1), Toll-like receptor 2 (TLR2), Toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) influence the susceptibility to pulmonary invasive fungal disease (IFD) in patients with acute myeloid leukemia (AML) from a Chinese Han population. Eight single nucleotide polymorphisms (SNPs) of Dectin-1 (rs16910526, rs3901533, and rs7309123), TLR2 (rs5743708), TLR4 (rs4986790 and rs4986791) and MyD88 (rs4988453 and rs4988457) in the genomic DNA of 172 adult AML patients were genotyped. Pulmonary IFD was diagnosed as proven or probable according to the 2008 European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) consensus guidelines. SNPs that were significant in the univariate analysis were further analyzed using the multiple logistic regression analysis to determine their association with the occurrence of pulmonary IFD. The mRNA expression of Dectin-1 was detected according to the genotype by quantitative realtime PCR (qRT-PCR), and the correlation of this expression with the occurrence of pulmonary IFD in AML patients was analyzed. Two Dectin-1 intron SNPs (rs3901533 and rs7309123) were found to be significantly associated with the susceptibility to pulmonary IFD in AML patients in a Chinese Han population. Significant associations were noted between pulmonary IFD and Dectin-1 rs3901533 dominant model (G/T+G/G vs. T/T, OR: 2.158; 95% CI: 1.109-4.2, P=0.02), Dectin-1 rs3901533 G allele (OR: 2.201; 95% CI: 1.206-4.019, P=0.01), or Dectin-1 rs7309123 C allele (OR: 1.919; 95% CI: 1.047-3.518, P=0.03). There were no significant associations between pulmonary IFD and the remaining Dectin-1 SNPs (rs16910526), TLR2 (rs5743708), TLR4 (rs4986790 and rs4986791) or MyD88 (rs4988453 and rs4988457). In conclusion, two Dectin-1 SNPs (rs3901533 and rs7309123) are associated with increased susceptibility to pulmonary IFD in AML patients in a Chinese Han population.

Modulating host immune responses to fight invasive fungal infections.

Modulation of host immunity in invasive fungal infection is an appealing but as yet mostly elusive treatment strategy. Animal studies in invasive candidiasis and aspergillosis have demonstrated beneficial effects of colony stimulating factors, interferon-gamma and monoclonal antibodies. More recent studies transfusing leukocytes pre-loaded with lipophilic anti-fungal drugs, or modulated T-cells, along with novel vaccination strategies show great promise. The translation of immune therapies into clinical studies has been limited to date but this is changing and the results of new Candida vaccine trials are eagerly awaited. Immune modulation in HIV-associated mycoses remains complicated by the risk of immune reconstitution inflammatory syndrome and although exogenous interferon-gamma therapy may be beneficial in cryptococcal meningitis, early initiation of anti-retroviral therapy leads to increased mortality. Further study is required to better target protective immune responses.

Host-Derived Biomarkers for Risk Assessment of Invasive Fungal Diseases.

Invasive fungal diseases are major complications associated with the treatment of hematologic malignancies. The integration of host-derived biomarkers into clinical processes to predict the risk and progression of fungal disease is a promising approach in immunocompromised patients. Recent insights into human antifungal immunity have highlighted the remarkable influence of host genetics in modulating susceptibility to infection. In this chapter, we describe protocols to examine human genetic variation and to assess its functional consequences using the pattern recognition receptor PTX3 as an example.