ABSTRACT
Polysaccharide is one of the principal bioactive components found in medicinal mushrooms and has been proven to enhance host immunity. However, the possible mechanism of immunomodulatory activity of Cordyceps militaris polysaccharide is not fully understood. Hot water extraction and alcohol precipitation, DEAE-Sephadex A-25 chromatography, and Sephadex G-100 chromatography were used to isolate polysaccharide from C. militaris. A high-molecular-weight polysaccharide isolated from C. militaris was designated as HCMP, which had an Mw of 6.18 × 105 Da and was composed of arabinose, galactose, glucose, mannose, and xylose in a mole ratio of 2.00:8.01:72.54:15.98:1.02. The polysaccharide content of HCMP was 91.2% ± 0.16. The test in vitro showed that HCMP activated mouse macrophage RAW 264.7 cells by enhancing phagocytosis and NO production, and by regulating mRNA expressions of inflammation-related molecules in RAW 264.7 cells. Western blotting revealed that HCMP induced the phosphorylation of mitogen-activated protein kinases (MAPKs). Moreover, using inhibitors of MAPKs decreased the mRNA levels of inflammation-related molecules induced by HCMP. These data evidenced that the immunomodulatory effect of HCMP on RAW 264.7 macrophages was mediated via the MAPK signaling pathway. These findings suggested that HCMP could be developed as a potent immunomodulatory agent for use in functional foods and dietary supplements.
Subject(s)
Cordyceps , MAP Kinase Signaling System , Macrophages , Phagocytosis , Animals , Mice , Cordyceps/chemistry , RAW 264.7 Cells , MAP Kinase Signaling System/drug effects , Macrophages/drug effects , Macrophages/metabolism , Phagocytosis/drug effects , Polysaccharides/pharmacology , Polysaccharides/chemistry , Polysaccharides/isolation & purification , Immunologic Factors/pharmacology , Immunologic Factors/chemistry , Immunologic Factors/isolation & purification , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/isolation & purification , Nitric Oxide/metabolism , Mitogen-Activated Protein Kinases/metabolismABSTRACT
Phellinus is a precious perennial medicinal fungus. Its polysaccharides are important bioactive components, and their chemical composition is complex. The polysaccharides are mainly extracted from the fruiting body and mycelium. The yield of the polysaccharides is dependent on the extraction method. They have many pharmacological activities, such as antitumor, immunomodulatory, antioxidant, hypoglycemic, anti-inflammatory, etc. They are also reported to show minor toxic and side effects. Many studies have reported the anticancer activity of Phellinus polysaccharides. This review paper provides a comprehensive examination of the current methodologies for the extraction and purification of Phellinus polysaccharides. Additionally, it delves into the structural characteristics, pharmacological activities, and mechanisms of action of these polysaccharides. The primary aim of this review is to offer a valuable resource for researchers, facilitating further studies on Phellinus polysaccharides and their potential applications.
Subject(s)
Fungal Polysaccharides , Humans , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/isolation & purification , Basidiomycota/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Polysaccharides/isolation & purification , Antioxidants/pharmacology , Antioxidants/chemistry , Antioxidants/isolation & purification , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/isolation & purification , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/isolation & purification , Animals , Phellinus/chemistryABSTRACT
Commercially available mushroom polysaccharides have found widespread use as adjuvant tumor treatments. However, the bioactivity of polysaccharides in Lactarius hatsudake Tanaka (L. hatsudake), a mushroom with both edible and medicinal uses, remains relatively unexplored. To address this gap, five L. hatsudake polysaccharides with varying molecular weights were isolated, named LHP-1 (898 kDa), LHP-2 (677 kDa), LHP-3 (385 kDa), LHP-4 (20 kDa), and LHP-5 (4.9 kDa). Gas chromatography-mass spectrometry, nuclear magnetic resonance, and atomic force microscopy, etc., were employed to determine their structural characteristics. The results confirmed that spherical aggregates with amorphous flexible fiber chains dominated the conformation of the LHP. LHP-1 and LHP-2 were identified as glucans with α-(1,4)-Glcp as the main chain; LHP-3 and LHP-4 were classified as galactans with varying molecular weights but with α-(1,6)-Galp as the main chain; LHP-5 was a glucan with ß-(1,3)-Glcp as the main chain and ß-(1,6)-Glcp connecting to the side chains. Significant differences were observed in inhibiting tumor cell cytotoxicity and the antioxidant activity of the LHPs, with LHP-5 and LHP-4 identified as the principal bioactive components. These findings provide a theoretical foundation for the valuable use of L. hatsudake and emphasize the potential application of LHPs in therapeutic tumor treatments.
Subject(s)
Antioxidants , Glucans , Glucans/chemistry , Glucans/pharmacology , Glucans/isolation & purification , Humans , Antioxidants/chemistry , Antioxidants/pharmacology , Antioxidants/isolation & purification , Agaricales/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Polysaccharides/isolation & purification , Molecular Weight , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Cell Line, Tumor , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/isolation & purification , Basidiomycota/chemistry , Cell Survival/drug effectsABSTRACT
Some macrofungi have a long history of being used as traditional or folk medicines, making significant contributions to human health. To discover bioactive molecules with potential anticancer properties, a homogeneous heteropolysaccharide (FOBP90-1) was purified from the medicinal macrofungus Fomitopsis officinalis. FOBP90-1 was found to have a molecular weight of 2.87 × 104 g/mol and mainly consist of â6)-α-d-Galp-(1â, â2,6)-α-d-Galp-(1â, â3)-α-l-Fucp-(1â, â6)-ß-d-Glcp-(1â, α-d-Manp-(1â, and 3-O-Me-α-l-Fucp-(1â according to UV, FT-IR, methylation analysis, and NMR data. In addition to its structural properties, FOBP90-1 displayed anticancer activity in zebrafish models. The following mechanistic analysis discovered that the in vivo antitumor effect was linked to immune activation and angiogenesis inhibition. These effects were mediated by the interactions of FOBP90-1 with TLR-2, TLR-4, PD-L1, and VEGFR-2, as determined through a series of experiments involving cells, transgenic zebrafish, molecular docking simulations, and surface plasmon resonance (SPR). All the experimental findings have demonstrated that FOBP90-1, a purified fungal polysaccharide, is expected to be utilized as a cancer treatment agent.
Subject(s)
Antineoplastic Agents , Coriolaceae , Fungal Polysaccharides , Zebrafish , Animals , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/isolation & purification , Humans , Coriolaceae/chemistry , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Cell Line, Tumor , Neoplasms/drug therapy , Vascular Endothelial Growth Factor Receptor-2/metabolism , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors , Molecular Docking SimulationABSTRACT
Fungal polysaccharides have been explored by many for both structural studies and biological activities, but few studies have been done on the extracellular polysaccharides of Dictyophora rubrovalvata, so a new exopolysaccharide was isolated from Dictyophora rubrovalvata and its structure and its immunological activity were investigated. The crude exopolysaccharide (EPS) was purified by DEAE52 cellulose and Sephadex G-200 to obtain a new acidic polysaccharide (DR-EPS). DR-EPS (2.66â¯×â¯103â¯kDa) was consisted mainly of mannose, glucose, galactose and glucuronic acid with a molar ratio of 1: 0.86: 0.20: 0.01. In addition, DR-EPS increased the phagocytic activity of RAW264.7 cells up to 2.67 times of the blank control group. DR-EPS improved intracellular nucleic acid and glycogen metabolism as observed by AO and PAS staining. DR-EPS(40⯵g/mL) promoted NO production up to 30.66⯵mol, enhanced acid phosphatase (ACP) and superoxide dismutase (SOD) activities, with activity maxima of 660â¯U/gprot and 96.27â¯U/mgprot, respectively, and DR-EPS (160⯵g / mL) significantly increased the lysozyme content as 2.73 times of the control group. The good immunological activity of extracellular polysaccharides of Dictyophora rubrovalvata provides directions for the use of fermentation broths.
Subject(s)
Fungal Polysaccharides , Mice , Animals , RAW 264.7 Cells , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/isolation & purification , Nitric Oxide/metabolism , Immunologic Factors/pharmacology , Immunologic Factors/chemistry , Immunologic Factors/isolation & purification , Phagocytosis/drug effects , Immunomodulating Agents/pharmacology , Immunomodulating Agents/chemistry , Immunomodulating Agents/isolation & purification , Superoxide Dismutase/metabolism , Macrophages/drug effects , Macrophages/metabolism , Macrophages/immunology , Acid Phosphatase/metabolismABSTRACT
In recent years, the considerable potential of endophytic bacteria and fungi as prolific producers of exopolysaccharides (EPSs) have attracted interest. In this study, 56 endophytes were isolated from Cyclocarya paliurus, and the secondary metabolites of EPSs were extracted from Monascus purpureus, Penicillium citrinum and Aspergillus versicolor, screened, and named MPE, PCE and AVE, respectively. In this work, the physicochemical properties and antioxidant activities of three EPSs, their cell proliferation activity on IEC-6 and RAW264.7 were investigated. The three EPSs were mainly composed of neutral sugar and differ in microstructure. However, MPE had a loose structure, and PCE exhibited a dense and sheet-like structure. In addition, the three EPSs performed ordinary antioxidant activity in vitro but showed excellent cell proliferation activity on IEC-6 and RAW264.7. The cell proliferation activity of PCE was 1.4-fold that of the controls at a concentration of 800 µg/mL on IEC-6, and MPE exhibited 1.3-fold increase on RAW264.7. This study provided scientific evidence and insights into the application of endophytes as a novel plant resource possessing huge application potential.
Subject(s)
Antioxidants , Cell Proliferation , Endophytes , Juglandaceae , Penicillium , Mice , Animals , Antioxidants/pharmacology , Antioxidants/chemistry , RAW 264.7 Cells , Endophytes/chemistry , Endophytes/metabolism , Cell Proliferation/drug effects , Juglandaceae/chemistry , Penicillium/chemistry , Penicillium/metabolism , Aspergillus/chemistry , Aspergillus/metabolism , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/isolation & purification , Monascus/chemistry , Monascus/metabolism , RatsABSTRACT
In this study, one water soluble polysaccharide (IOP1-1) with a weight average molecular weight of 6886 Da was obtained from the black crystal region of Inonotus obliquus by hot water extraction, DEAE-52 cellulose extraction and Sephadex-100 column chromatography purification. Structural analysis indicated that IOP1-1 was a glucan with a main chain composed of α-Glcp-(1 â 4)-α-Glcp-(1 â 4)-ß-Glcp-(1 â 4)-ß-Glcp-(1 â 4)-α-Glcp-(1 â 6)-ß-Glcp-(1 â 4)-α-Glcp-(1 â 3)-ß-Glcp-(1â. The CCK-8 assay results showed that IOP1-1 inhibited AsPC-1 and SW1990 pancreatic cancer cell proliferation in a concentration-dependent manner. Flow cytometric analysis revealed that IOP1-1 induced cell cycle arrest in AsPC-1 and SW1990 cells. Hoechst 33342 staining and Annexin V-FITC/PI double staining analysis showed that IOP1-1 could induce apoptosis in AsPC-1 and SW1990 cells. Furthermore, western blot analysis confirmed that IOP1-1 could induce apoptosis in AsPC-1 and SW1990 pancreatic cancer cells through three pathways: the mitochondrial pathway, the death receptor pathway, and endoplasmic reticulum stress. According to these research data, IOP1-1 may be utilized as an adjuvant treatment to anticancer medications, opening up new application prospects and opportunities.
Subject(s)
Apoptosis , Cell Proliferation , Inonotus , Pancreatic Neoplasms , Humans , Apoptosis/drug effects , Cell Line, Tumor , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/pathology , Pancreatic Neoplasms/metabolism , Cell Proliferation/drug effects , Inonotus/chemistry , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/isolation & purification , Polysaccharides/pharmacology , Polysaccharides/chemistry , Polysaccharides/isolation & purification , Molecular Weight , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistryABSTRACT
Macrofungi, a class of unique natural resources, are gaining popularity owing to their potential therapeutic benefits and edibility. From Fomitopsis officinalis, a medicinal macrofungus with anticancer activity, a homogeneous heteropolysaccharide (FOBP50-1) with a molecular weight of 2.21â¯×â¯104â¯g/mol has been extracted and purified. FOBP50-1 was found to be composed of 3-O-methylfucose, fucose, mannose, glucose, and galactose with a ratio of 1: 6.5: 4.4: 8.1: 18.2. The sugar fragments and structure of FOBP50-1 were investigated, which included â6)-α-d-Galp-(1â, â2,6)-α-d-Galp-(1â, â3)-α-l-Fucp-(1â, α-d-Glcp-(1â, â3)-ß-d-Manp-(1â, â6)-ß-d-Manp-(1â, 3-O-Me-α-l-Fucp-(1â, according to the UV, FT-IR, GC-MS, and NMR data. Besides the structure elucidation, FOBP50-1 showed promising antitumor activity in the zebrafish assays. The following mechanism examination discovered that FOBP50-1 interacted with TLR-4, PD-1, and VEGF to activate immunity and inhibit angiogenesis according to a series of cell, transgenic zebrafish, and surface plasmon resonance (SPR) experiments. The KD values indicating the association of FOBP50-1 with TLR-4, PD-1, and VEGF, were 4.69â¯×â¯10-5, 7.98â¯×â¯10-6, 3.04â¯×â¯10-6â¯M, respectively, in the SPR experiments. All investigations have demonstrated that the homogenous fungal polysaccharide FOBP50-1 has the potential to be turned into a tumor immunotherapy agent.
Subject(s)
Angiogenesis Inhibitors , Antineoplastic Agents , Fungal Polysaccharides , Zebrafish , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/isolation & purification , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Angiogenesis Inhibitors/pharmacology , Angiogenesis Inhibitors/chemistry , Angiogenesis Inhibitors/isolation & purification , Humans , Coriolaceae/chemistry , Neovascularization, Pathologic/drug therapy , Vascular Endothelial Growth Factor A/metabolism , Mice , AngiogenesisABSTRACT
Polysaccharides derived from Auricularia auricula exhibit diverse biological activities and hold significant potential for commercial utilization as functional food ingredients. In this investigation, polysaccharides from A. auricula were obtained using six extraction techniques (ammonium oxalate solution extraction, sodium hydroxide solution extraction, hot water extraction, pectinase and cellulase-assisted extraction, ultrasonic-assisted extraction, and microwave-assisted extraction). Subsequently, a comprehensive comparison was conducted to evaluate their physicochemical properties and biological functionalities. The ammonium oxalate solution extraction method yielded a higher extraction rate (11.76%) and polysaccharide content (84.12%), as well as a higher uronic acid content (10.13%). Although the six Auricularia polysaccharides had different molecular weight distributions, monosaccharide molar ratios, similar monosaccharide compositions, and characteristic functional groups of polysaccharides, they exhibited different surface morphology. In vitro assays showed that polysaccharides extracted by ammonium oxalate solution possessed good scavenging ability against DPPH free radical, hydroxyl free radical and superoxide anion free radical as well as reduction power of iron ion. At the same time, both polysaccharides extracted by ammonium oxalate solution and sodium hydroxide solution promoted NO production in mouse macrophages along with the secretion of cytokines TNF-α, IL-1ß, and IL-6. These results indicated significant differences in the structure and characteristics among Auricularia polysaccharides prepared by various extraction methods, which may be related to the variety or origin of A. auricula; furthermore, their bioactivities varied accordingly in vitro assays where the ammonium oxalate solution extraction method was found more beneficial for obtaining high-quality bioactive Auricularia polysaccharides.
Subject(s)
Auricularia , Mice , Animals , Auricularia/chemistry , RAW 264.7 Cells , Fungal Polysaccharides/pharmacology , Fungal Polysaccharides/isolation & purification , Fungal Polysaccharides/chemistry , Polysaccharides/pharmacology , Polysaccharides/isolation & purification , Polysaccharides/chemistry , Molecular Weight , Nitric Oxide , Chemical Fractionation/methods , Free Radical Scavengers/isolation & purification , Free Radical Scavengers/pharmacology , Free Radical Scavengers/chemistry , Antioxidants/pharmacology , Antioxidants/isolation & purification , Antioxidants/chemistry , Macrophages/drug effects , Macrophages/metabolismABSTRACT
Background. Cryptococcus neoformans is an encapsulated yeast causing mainly opportunistic infections. The virulence factors involved in cryptococcosis pathogenesis include the presence and the size of the polysaccharide capsule, the production of melanin by phenoloxidase, the growth at 37°C and the enzyme secretion like proteinase, phospholipase and urease. Many other enzymes are secreted by C. neoformans but their role in the fungus virulence is not yet known. Aims. In order to investigate this topic, we compared the phospholipase production between strains from patients and from bird droppings, and we examined its relationship to phenoloxidase production. We further characterized the strains by determining the activity of 19 different extracellular enzymes. Methods. Two hundred and five Italian C. neoformans clinical isolates and 32 environmental isolates were tested. Phenoloxidase production was determined by the development of brown colonies on Staib's agar. Extracellular phospholipase activity was performed using the semiquantitative egg-yolk plate method. API ZYM commercial kit was used to observe the production and the activity of 19 different extracellular enzymes. Results. Statistical analysis of the results showed a significantly higher phospholipase activity in the clinical isolates than in the environmental isolates. No significant difference about the phenoloxidase production between both groups was found. Regarding the 19 extracellular enzymes tested using the API ZYM commercial kit, acid phosphatase showed the highest enzymatic activity in both groups. Concerning the enzyme α-glucosidase, the clinical isolates presented a significantly higher positivity percentage than the environmental isolates. A hundred percent positivity in the enzyme leucine arylamidase production was observed in both groups, but the clinical isolates metabolized a significantly greater amount of substrate. Conclusions. The higher phospholipase production in the clinical isolates group confirms the possible role of this enzyme in the cryptococcosis pathogenesis. The extracellular activities of the enzymes acid phosphatase, α-glucosidase and leucine arylamidase, tested by means of the API ZYM commercial kit, appear to be very interesting. Many studies indicate that these enzymes are involved in the virulence of bacteria and parasites; our results suggest their possible role as virulence factors in Cryptococcus infections too (AU)
Antecedentes. Cryptococcus neoformans es una levadura encapsulada que produce infecciones oportunistas. Los factores de virulencia involucrados en la patogénesis de la criptococosis incluyen la existencia y el tamaño de la cápsula polisacarídica, la producción de melanina por medio de la enzima fenoloxidasa, el crecimiento a 37°C y la secreción de ciertas enzimas como proteinasa, fosfolipasa y ureasa. Existen otras enzimas que son secretadas por C. neoformans, pero su papel en la virulencia de este hongo aún no es conocido. Objetivos. Se investigó la producción de fosfolipasa tanto en aislamientos de C. neoformans obtenidos de pacientes como de aislamientos recuperados de deposiciones de aves, y se comparó el grado de producción con el de la síntesis de la enzima fenoloxidasa. Además, distingue las cepas mediante la definición de la actividad de 19 enzimas extracelulares diferentes. Métodos. Se estudiaron 205 aislamientos clínicos de C. neoformans y 32 ambientales. La producción de fenoloxidasa se determinó por el crecimiento de colonias de color marrón en medio de Staib. Para determinar la actividad fosfolipasa extracelular se utilizó el método semicuantitativo en placa con yema de huevo. Con el método comercial API ZYM se determinó la producción de otras 19 enzimas extracelulares. Resultados. El análisis estadístico de los resultados mostró una producción de fosfolipasa significativamente mayor entre los aislamientos clínicos en comparación con los ambientales. No se encontraron diferencias significativas entre ambos grupos en la producción de fenoloxidasa. En lo referente a las 19 enzimas extracelulares valoradas mediante el sistema API ZYM, la fosfatasa ácida mostró la mayor actividad en ambos grupos. Respecto a la enzima α-glucosidasa, nuevamente los aislamientos clínicos presentaron una actividad significativamente mayor. Todos los aislamientos de ambos grupos presentaron actividad leucina-arilamidasa, si bien los aislamientos clínicos procesaron mayor cantidad de sustrato de manera significativa. Conclusiones. La mayor producción de enzima fosfolipasa entre los aislamientos clínicos evidencia que esta enzima puede estar implicada en la patogénesis de la criptococosis. También es interesante la actividad extracelular de las enzimas fosfatasa ácida, α-glucosidasa y leucina-arilamidasa, valorada por medio del sistema comercial API ZYM. Diversos estudios apuntan a que estas enzimas están implicadas en la virulencia de bacterias y parásitos; nuestros resultados muestran también su posible implicación como factores de virulencia en las infecciones por Cryptococcus (AU)
Subject(s)
Humans , Cryptococcosis/enzymology , Cryptococcus neoformans/enzymology , Cryptococcus neoformans/pathogenicity , Phospholipases/analysis , Fungal Polysaccharides/isolation & purification , Melanins/analysis , Monophenol Monooxygenase/analysisABSTRACT
Introducción. Comparar las pruebas de antígeno galactomanano (AG) y moleculares (PCRrt) con el cultivo para el diagnóstico de aspergilosis invasiva (AI). Material y métodos. Se analizaron 472 muestras: 388 respiratorias, 84 sueros, de 271 pacientes. En las respiratorias se realizó cultivo y AG y en los sueros AG. En caso de discordancia entre ellas se realizó PCR. Resultados. El AG resultó positivo en 22 sueros de 84, 21 tenían esta prueba positiva en muestra respiratoria. De 62 sueros con AG negativo, 45 fueron también negativas en muestras respiratorias. El cultivo fue positivo en 37, coincidiendo todas con AG positivo. Comparando cultivo con AG, éste mostró un VPP= 23%, VPN=100%, S= 100% y E=52%. La PCRrt respecto al cultivo mostró un VPP= 69%, VPN= 89%, S= 64% y E= 82%. En los sueros entre AG y PCR encontramos 60% de discrepancias. Conclusiones. Consideramos muy útil la detección de AG en suero combinada con cultivo y AG en muestras respiratorias para el diagnóstico de AI, precisando PCRrt más estudios para su estandarización y establecer puntos de corte (AU)
Introduction. The aim of the study was to compare the galactomannan antigen (GA) and molecular biology (PCRrt) tests with the culture in the diagnosis of invasive aspergillosis (IA). Material and methods. Four hundred and seventy two samples were analyzed: 388 respiratory and 84 serum samples from 271 patients. Culture and GA were evaluated in the respiratory samples and GA in the serum samples. PCR was used when discrepancies were observed among culture and GA tests. Results. The detection of GA in serum was positive in 22 (of 84), 21 had the test positive respiratory sample. Of the 62 sera with negative GA, 45 were also negative respiratory specimens. The culture was positive in 37 of which were positive for GA. Comparing culture with AG, it showed PPV=23%, NPV=100%, S=100% and E=52%. The PCR showed respect to culture: PPV=69%, NPV=89%, S=64% and E=82%. In sera were found in 60% discrepancies between PCRrt and GA. Conclusions. We consider useful the GA detection in serum combined with culture and GA in respiratory samples, for diagnosis of AI. PCR requires further studies for standardization and set breakpoints (AU)