Ultrasensitive Enzyme-linked Immunosorbent Assay Research Articles

Surgical eye spears for saliva collection and secretory immunoglobulin A measurements.

We examined the use of surgical eye spears for saliva collection and recovery of secretory immunoglobulin A (s-IgA). We established a protocol for recovering s-IgA at concentrations equivalent to those present in the control samples (untreated by surgical eye spears). Four different types of eye spears were submerged in the salivary fluid. Saliva was recovered from each spear by centrifugation. Novel ultra-sensitive enzyme-linked immunosorbent assay was used to determine s-IgA concentration in each sample. The results revealed that Weck-Cel eye spears recovered s-IgA at concentrations not significantly different from s-IgA concentrations in control samples as long as the appropriate protocol was followed. We demonstrated that the use of surgical eye spears for saliva collection is a viable method for recovering s-IgA. (J Oral Sci 58, 205-210, 2016).

DNA-Redox Cation Interaction Improves the Sensitivity of an Electrochemical Immunosensor for Protein Detection.

A simple DNA-redox cation interaction enhancement strategy has been developed to improve the sensitivity of electrochemical immunosensors for protein detection. Instead of labeling with fluorophores or redox-active groups, the detection antibodies were tethered with DNA single strands. Based on the electrostatic interaction between redox cations ([Ru(NH3)6]3+) and negatively charged DNA backbone, enhanced electrochemical signals were obtained. Human chorionic gonadotropin (hCG) detection has been performed as a trial analysis. A linear response range up to the concentration of 25 mIU/mL and a detection limit of 1.25 mIU/mL have been achieved, both are comparable with the ultrasensitive enzyme-linked immunosorbent assay (ELISA) tests. The method also shows great selectivity towards hCG over other hormones such as thyroid stimulating hormone (TSH) and follicle stimulating hormone (FSH). By and large, our approach bears the merits of cost effectiveness and simplicity of instrumentation in comparison with conventional optical detection methods.

Development and Application of an Ultrasensitive Hybridization-Based ELISA Method for the Determination of Peptide-Conjugated Phosphorodiamidate Morpholino Oligonucleotides.

Antisense oligonucleotide (AON)-induced exon skipping is one of the most promising strategies for treating Duchenne muscular dystrophy (DMD) and other rare monogenic conditions. Phosphorodiamidate morpholino oligonucleotides (PMOs) and 2'-O-methyl phosphorothioate (2'OMe) are two of the most advanced AONs in development. The next generation of peptide-conjugated PMO (P-PMO) is also showing great promise, but to advance these therapies it is essential to determine the pharmacokinetic and biodistribution (PK/BD) profile using a suitable method to detect AON levels in blood and tissue samples. An enzyme-linked immunosorbent assay (ELISA)-based method, which shows greater sensitivity than the liquid chromatography-mass spectrometry method, is the method of choice for 2'OMe detection in preclinical and clinical studies. However, no such assay has been developed for PMO/P-PMO detection, and we have, therefore, developed an ultrasensitive hybridization-based ELISA for this purpose. The assay has a linear detection range of 5-250 pM (R(2)>0.99) in mouse serum and tissue lysates. The sensitivity was sufficient for determining the 24-h PK/BD profile of PMO and P-PMO injected at standard doses (12.5 mg/kg) in mdx mice, the dystrophin-deficient mouse model for DMD. The assay demonstrated an accuracy approaching 100% with precision values under 12%. This provides a powerful cost-effective assay for the purpose of accelerating the development of these emerging therapeutic agents.

Development of novel monoclonal antibodies-based ultrasensitive enzyme-linked immunosorbent assay and rapid immunochromatographic strip for aflatoxin B1 detection

Monoclonal antibodies (mAbs) that are specific to aflatoxin B1 (AFB1) were produced from hybridoma cell lines 3F6G11 and 9C7C11 by the fusion of P3/NS1/1-AG4-1 myeloma cells with spleen cells that were isolated from a BALB/c mouse that was immunized with AFB1-bovine serum albumin (BSA). Both 3F6G11 and 9C7C11 mAbs are the immunoglobulin G1 isotypes. Competitive direct enzyme-linked immunosorbent assays (cdELISA) were established to characterize these antibodies. In the 3F6G11 mAb based cdELISA, the concentrations causing 50% inhibition of binding of AFB1-horseradish peroxidase to the antibody by AFB1, AFB2, AFG1, and AFG2 were found to be 0.051, 0.050, 1.820, and 1.270 ng/ml, respectively. Using 9C7C11 mAbs, similar IC50 values for AFB1, AFB2, AFG1 and AFG2 were obtained as 0.045, 0.057, 2.530 and 2.120 ng/ml, respectively. A rapid and sensitive gold nanoparticle immunochromatographic strip (immunostrip) was also established for these antibodies. This strip has a detection limit of 1.0 ng/ml for AFB1 and the whole assay can be completed within 10 min. Extensive analysis of 20 samples by 3F6G11 mAb and 9C7C11 mAbs cdELISAs revealed that six samples were slightly contaminated by AFB1 at concentrations from 0.160 to 16.10 ng/g. Results of analyses of 20 samples with an immunostrip assay correlate well with those obtained using cdELISA. The proposed cdELISA and immunostrip methods are highly sensitive for the rapid screening of AFB1 in food samples.

Ultra-sensitive protein detection via Single Molecule Arrays towards early stage cancer monitoring

The early diagnosis of cancers and continued monitoring of tumor growth would be greatly facilitated by the development of a blood-based, non-invasive, screening technique for early cancer detection. Current technologies for cancer screening and detection typically rely on imaging techniques or blood tests that are not accurate or sensitive enough to definitively diagnose cancer at its earliest stages or predict biologic outcomes. By utilizing Single Molecule Arrays (SiMoA), an ultra-sensitive enzyme-linked immunosorbent assay (ELISA) technique, we were able to measure increasing levels of prostate specific antigen (PSA) within murine serum over time, which we attribute to tumor development. The measured concentrations of PSA were well below the detectable limits of both a leading clinical diagnostic PSA ELISA assay as well as a commercial ultra-sensitive PSA assay. Our work benchmarks the role of SiMoA as a vital tool in monitoring previously non-detectable protein biomarkers in serum for early cancer detection and offers significant potential as a non-invasive platform for the monitoring of early stage cancer.

Zinc oxide nanoparticle-enhanced ultrasensitive chemiluminescence immunoassay for the carcinoma embryonic antigen

An ultrasensitive enzyme-linked immunosorbent assay (ELISA) is reported for the determination of carcinoma embryonic antigen (CEA) in human serum. It was realized using a microplate reader using a 384-well plate. Monoclonal antibody (Ab) against CEA (1° Ab) acting as the capture probe was immobilized on zinc oxide nanoparticles (ZnO-NPs) in the form of self-assembled monolayers (SAMs). CEA captured by 1° Ab was quantified using a sandwich ELISA wherein a polyclonal second antibody against CEA (2° Ab) was used for detection and quantified using an HRP-labeled secondary antibody (3° Ab). The ZnO-NPs-CEA capture probe was deposited on the bottom of the wells in order to enhance capture of CEA. A 3-fold enhancement in the chemiluminescence (CL) signal of luminol is found (compared to a conventional ELISA). CEA can be quantified by this method in concentrations as low as 1 pg · mL−1. The upper limit of detection is 20 ng · mL−1. The use of ZnO-NPs also imparts improved thermal stability. When stored at 4 °C in phosphate-buffered saline of pH 7.4, the probe displays stability of up to 30 days.

Development of an ultrasensitive immunoassay using affinity maturated antibodies for the measurement of rodent insulin

The measurement of plasma insulin is important for clinical diagnosis of diabetes and for preclinical research of metabolic diseases, especially in rodent models used in drug discovery research for type 2 diabetes. Fasting immunoreactive insulin (F-IRI) concentrations are used to calculate the homeostasis model assessment ratio (HOMA-R), an index of insulin sensitivity. However, even the most sensitive commercially available enzyme-linked immunosorbent assay (ELISA) kits cannot measure the very low F-IRI concentrations in normal rats and mice. Therefore, we sought to develop a new rodent insulin ELISA with greater sensitivity for low F-IRI concentrations. Despite repeated efforts, high-affinity antibodies could not be generated by immunizing mice with mouse insulin (self-antigen). Therefore, we generated two weak monoclonal antibodies (13G4 and 26B2) that were affinity maturated and used to develop a highly sensitive ELISA. The measurement range of the sandwich ELISA with the affinity maturated antibodies (13G4m1 and 26B2m1) was 1.5 to 30,000pg/ml, and its detection limit was at least 10 times lower than those of commercially available kits. In conclusion, we describe the development of a new ultrasensitive ELISA suitable for measuring very low plasma insulin concentrations in rodents. This ELISA might be very useful in drug discovery research in diabetes.

Phytoplankton Community Shifts and Harmful Algae Presence in a Diversion Influenced Estuary

River water entering estuaries affects the physical and chemical environment at irregular intervals creating a highly dynamic aquatic habitat. Phytoplankton are important primary producers in estuaries that respond quickly to their changing environment. Over a 12-month period, the phytoplankton response was examined in terms of biomass, abundance, community composition, and potential phycotoxin production to seasonal changes in river input entering the Breton Sound Estuary in Louisiana. Chlorophyll a (chl a) measurements estimated phytoplankton biomass and light microscopy identified phytoplankton abundance and community composition. Phycotoxins were measured using ultra-sensitive enzyme-linked immunosorbent assay (ELISA). During the study period, chl a and cell abundances exhibited an inverse relationship with the seasons, which were determined by temperature and diversion input rates. The community was dominated by cyanobacteria for most of the year, mainly corresponding to the warm-low flow season. For the rest of the year, cyanobacteria decreased while chlorophytes and centric diatoms increased to approximately equal contributions. Overall, the phytoplankton community composition was most commonly moderated by temperature, salinity, and dissolved inorganic nitrogen (DIN) availability using BIO-ENV. Microcystins (MCs) were detected throughout the year ranging from below detection to 2.92 μg MCs l−1. MC levels were highest during the warm-low flow season and toward the lower estuary. The detection of MCs for the first time in the Breton Sound Estuary illustrates a potential risk to human health and economically important estuarine food webs.

Ultrasensitive ELISA using enzyme-loaded nanospherical brushes as labels.

Improving the detection sensitivity of enzyme-linked immunosorbent assay (ELISA) is of utmost importance for meeting the demand of early disease diagnosis. Herein we report an ultrasensitive ELISA system using horseradish peroxidase (HRP)-loaded nanospherical poly(acrylic acid) brushes (SPAABs) as labels. HRP was covalently immobilized in SPAABs with high capacity and activity via an efficient "chemical conjugation after electrostatic entrapment" (CCEE) process, thus endowing SPAABs with high amplification capability as labels. The periphery of SPAAB-HRP was further utilized to bind a layer of antibody with high density for efficient capture of analytes owing to the three-dimensional architecture of SPAABs. Using human chorionic gonadotrophin (hCG) as a model analyte, the SPAAB-amplified system drastically boosted the detection limit of ELISA to 0.012 mIU mL(-1), a 267-fold improvement as compared to conventional ELISA systems.

An ultra-sensitive monoclonal antibody-based competitive enzyme immunoassay for sterigmatocystin in cereal and oil products.

Sterigmatocystin (STG), a biosynthesis precursor of aflatoxin B1, is well known for its toxic and carcinogenic effects in humans and animals. STG derivatives and protein conjugates are needed for generation of monoclonal antibodies (mAbs). This work describes a reliable and fast synthesis of novel STG derivatives, based on which novel STG bovine serum albumin conjugates were prepared. With the novel STG bovine serum albumin conjugates, three sensitive and specific mAbs against STG, named VerA 3, VerA 4, and VerA 6, were prepared by semi-solid hypoxanthine/aminopterin/thymidine (HAT) medium using a modified two-step screening procedure. They exhibited high affinity for STG and no cross-reactivity (CR) with aflatoxins B1, B2, G1, G2, and M1. Based on the most sensitive antibody VerA 3, an ultra-sensitive competitive enzyme-linked immunosorbent assay (ELISA) was developed for STG in wheat, maize, and peanuts. Assays were performed in the STG-GA-BSA-coated (0.5 µg·mL−1) ELISA format, in which the antibody was diluted to 1∶80,000. Several physicochemical factors influencing assay performance, such as pH, ionic strength, blocking solution, and diluting solution, were optimized. The final results showed that the assays had the detection limits of 0.08 ng·g−1 for wheat, 0.06 ng·g−1 for maize, and 0.1 ng·g−1 for peanuts, inter-assay and intra-assay variations of less than 10%, and recoveries ranging from 83% to 110%. These recoveries were in good agreement with those obtained by using HPLC-MS/MS method (90–104%), indicating the importance of the mAb VerA 3 in the study of STG in crude agricultural products.

Altered cytokine and chemokine profiles in multiple myeloma and its precursor disease

Currently, no reliable biomarkers are available to predict transformation from smoldering myeloma (SMM) to multiple myeloma (MM). Using an ultrasensitive enzyme-linked immunosorbent assay (ELISA) we assessed the levels of a broad range of cytokines and chemokines in the peripheral blood (PB) and bone marrow (BM) supernatant collected from 14 SMM and 38 MM patients and compared to healthy donors. We found significantly increased levels of key cytokines, in particular CXCL8 (IL-8), associated with progressive disease state (controls→SMM→MM). Cytokine profiles were found similar in PB and BM. Five of fourteen SMM patients (36%) progressed to MM.Our findings, although based on a limited number of patients, suggest that serum-based cytokines may have a future role as biomarkers for disease progression and could potentially be assessed as novel targets for treatment.

Production of Monoclonal Antibody for Okadaic Acid and Its Utilization in an Ultrasensitive Enzyme-Linked Immunosorbent Assay and One-Step Immunochromatographic Strip

Okadaic acid (OA) is a common marine biotoxin that accumulates in bivalves and causes diarrhetic shellfish poisoning (DSP). This study generated a monoclonal antibody (mAb) specific to OA from a hybridoma cell line, 6B1A3, which was obtained by fusion of myeloma cells (P3/NS1/1-AG4-1) with spleen cells isolated from a BALB/c mouse immunized with OA-γ-globulin. The 6B1A3 mAb belongs to the immunoglobulin G1 (κ chain) isotype. Both competitive direct and indirect enzyme-linked immunosorbent assays (ELISAs) were established for characterization of the antibody. The concentrations causing 50% inhibition of binding of OA-horseradish peroxidase to the antibody by OA were calculated to be 0.077 ng/mL in the cdELISA. A rapid and sensitive mAb-based gold nanoparticle immunochromatographic strip was also established. This proposed strip has a detection limit of 5 ng/mL for OA and can be finished in 10 min. Extensive analyses of 20 seafood samples with ELISA revealed that 10 were slightly contaminated with OA, with a mean concentration of 0.892 ng/g. Analysis of OA in shellfish samples showed that data acquired by the immunochromatographic strip agreed well with those acquired by the ELISA. The mAb-based ELISA and immunochromatographic strip assay developed in this study have adequate sensitivity and accuracy for rapid screening of OA in shellfish samples.

Ultrasensitive enzyme-linked immunosorbent assay (ELISA) of proteins by combination with the thio-NAD cycling method.

An ultrasensitive method for the determination of proteins is described that combines an enzyme-linked immunosorbent assay (ELISA) and a thionicotinamide-adenine dinucleotide (thio-NAD) cycling method. A sandwich method using a primary and a secondary antibody for antigens is employed in an ELISA. An androsterone derivative, 3α-hydroxysteroid, is produced by the hydrolysis of 3α-hydroxysteroid 3-phosphate with alkaline phosphatase linked to the secondary antibody. This 3α-hydroxysteroid is oxidized to a 3-ketosteroid by 3α- hydroxysteroid dehydrogenase (3α-HSD) with a cofactor thio-NAD. By the opposite reaction, the 3-ketosteroid is reduced to a 3α-hydroxysteroid by 3α-HSD with a cofactor NADH. During this cycling reaction, thio-NADH accumulates in a quadratic function-like fashion. Accumulated thio-NADH can be measured directly at an absorbance of 400 nm without any interference from other cofactors. These features enable us to detect a target protein with ultrasensitivity (10−19 mol/assay) by measuring the cumulative quantity of thio-NADH. Our ultrasensitive determination of proteins thus allows for the detection of small amounts of proteins only by the application of thio-NAD cycling reagents to the usual ELISA system.

Distribution of plasma C-reactive protein measured by high-sensitivity assay in healthy Nigerian adults

Background: The plasma levels of C-reactive protein (CRP) within the reference interval have been shown to be a strong predictor of coronary heart disease (CHD) and are being considered in cardiovascular disease risk assessment. And for effective utilization of CRP in this regard, its distribution among healthy individuals in the general population should be established, using the high-sensitivity CRP (hsCRP). Aim: The aim of this study was to describe the plasma distribution of hsCRP concentration in healthy adult Nigerians and to estimate the proportions of those at high risk for cardiovascular disease. Materials and Methods: hsCRP glucose, total cholesterol, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C) and triglycerides were measured in 120 adult Nigerians free of clinical and biochemical features, suggestive of cardiovascular disease and not on any form of hormonal therapy. The blood pressure, height and weight of the participants were also measured. hsCRP was measured by synthron CRP ultrasensitive enzyme-linked immunosorbent assay method, glucose was measured by the glucose oxidase method, while the lipid profile parameters were measured by enzymatic colorimetric methods. Results: hsCRP concentration ranged from 0.62 to 11.64 mg/L (median: 1.3 mg/L, mean: 2.3 mg/L, 95% confidence interval, 0.75-11.0 mg/L). About 81.7%, 15.0%, and 3.3% of the participants had hsCRP concentrations of less than 3 mg/L, 3-10 mg/L, and higher than 10 mg/ L, respectively. The plasma levels of glucose and lipid profile parameters were within the reference limits established at the Chemical Pathology Laboratory of Aminu Kano Teaching Hospital (AKTH). None of the participants was obese (mean body mass index was 18.6 kg/m 2 ). Conclusion: This study describes the plasma distribution of hsCRP in healthy Nigerian adults. The results obtained would be of further help in the risk-assessment of individuals for future cardiovascular disease.

Detection of In Utero Marijuana Exposure by GC-MS, Ultra-Sensitive ELISA and LC-TOF-MS Using Umbilical Cord Tissue

Smoking marijuana during pregnancy can cause health problems in the neonate. The detection of exposure can guide treatment to meet the short- and long-term medical and social needs. Umbilical cord tissue was analyzed for 11-nor-delta-9-carboxy-tetrahydrocannabinol (THC-COOH) by gas chromatography-mass spectrometry (GC-MS), and compared with ultra-sensitive enzyme-linked immunosorbent assay (ELISA) and liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS). Fortified extracts of drug-free cord tissue were used to determine the sensitivity and specificity of the LC-TOF-MS and ELISA assays, and 16 de-identified patient specimens previously analyzed by GC-MS were tested for THC-COOH by both methods. The cutoffs were 0.050 ng/g for the GC-MS assay, 0.1 ng/g for the ELISA assay and 1 ng/g for the LC-TOF-MS assay. Twelve specimens were negative by all three methods. Seven specimens were positive by GC-MS with concentrations from 0.066 to 6.095 ng/g. ELISA and LC-TOF-MS did not detect one specimen that was positive by GC-MS. LC-TOF-MS missed one specimen that was detected by GC-MS and ELISA. Five positive specimens were detected by all three methods. These results were consistent with the cutoff for each method. No false positives were detected by LC-TOF-MS or ELISA. Umbilical cord tissue is a viable specimen for the detection of in utero marijuana exposure. ELISA and GC-MS were more sensitive than LC-TOF-MS for the detection of THC-COOH in cord tissue, with the GC-MS method providing superior sensitivity.

Development of an Ultrasensitive Immunoassay for Detecting Tartrazine

We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages.

Development of an ultrasensitive hetero-sandwich ELISA assay based on bispecific monoclonal antibody for the detection of dengue NS1 protein

BackgroundDengue is one of the major public health concern affecting nearly 2.5 billion people throughout the world. Development of a safe, cost effective and sensitive diagnostic test for the detection of dengue is of great significance. This will help to control the early infections particularly for children and young adults who are the most susceptible. This article outlines the development of a quadroma-based capture enzyme-linked immunosorbent assay (ELISA) for the diagnosis of the dengue virus nonstructural protein NS1. MethodsBy using the bsmAb capture-antibody, the sensitivity of the sandwich ELISA assay developed, and used for the early detection of dengue infections. Results and discussionWe were able to establish a detection sensitivity of 31.25 pg/ml for NS1 protein from dengue 1 virus. A significant feature of the assay is, that it reduces the number of steps required to determine detection thus reducing the cost of the diagnosis. ConclusionThe ELISA assay developed is very sensitive, quicker, more sensitive and cheaper to administer, has the potential to become another useful diagnostic tool for the detection of dengue virus.

Immunodiagnostics: Major Advances and Future Insights

There have been tremendous advances in immunodiagnostics during the last five decades, which have led to the emergence of potential diagnostic technologies, new immunoassay formats and diagnostic platforms. The radioimmunoassay and Enzyme Linked Immunosorbent Assay (ELISA) were the predominant techniques during the initial era of immunodiagnostics. The strenuous research efforts during the last three decades have enabled the development of potential antibodies for a wide range of analytes. Till date,t ELISA has been the gold standard of clinical immunodiagnostics, which has also been used very frequently for industrial analysis, environmental monitoring, food analysis and bioanalytical sciences. Despite the numerous advances in the field, it is difficult for any other technique to achieve the same high sensitivity, specificity, precision and throughput as ELISA. Various robotic work stations have been devised to perform automated ELISAs in high volume settings, such as in hospitals and industry. Similarly, the Microtiter Plate (MTP) readers have been improved significantly in terms of optics, technology and data analysis. In addition to conventional 96-well MTP format, various high throughput formats, such as 384 and 1536 wells, have also been devised for specific needs. The last two decades have seen considerable improvements in antibody immobilization strategies [1-3], which have significantly improved the analytical performance of ELISA in terms of higher sensitivity, greater detection range, lower limit of detection and reduced assay duration [4-6]. Similarly, the sample preparation strategies and screening of immunological components have also been critically improved, which enables highly reproducible immunoassays [7,8]. The development of highly sensitive enzyme substrates have led to ultrasensitive ELISAs and chemiluminescent immunoassays [9], while the use of superior fluorescent dyes improved the fluorescent immunoassays. Additionally, the use of infra-red dyes, quantum dots, gold nanoparticles, beads, and other nanomaterial/nanocomposites enabled the development of new ELISA formats, such as the naked-eye ELISA that was demonstrated using gold nanoparticles [10].

Maternal Periodontal Disease is Associated with Oxidative Stress during Pregnancy

We sought to determine if maternal periodontal disease is associated with oxidative stress as measured by serum 8-isoprostane. A secondary analysis was conducted using prospective data from the Oral Conditions and Pregnancy Study. Healthy women enrolled at < 26 weeks' gestational age underwent oral examination and serum sampling. Maternal periodontal disease status was categorized as healthy, mild, or moderate to severe by clinical criteria. Maternal serum was analyzed for 8-isoprostane using ultrasensitive enzyme-linked immunosorbent assay. Elevated 8-isoprostane level was defined as ≥ 75th percentile. Maternal factors associated with elevated 8-isoprostane were determined using chi-square or T test. Multivariable logistic regression was used to assess association between elevated 8-isoprostane and maternal factors. Seven hundred ninety-one women had complete data. Median (interquartile) 8-isoprostane serum level was 1806 (16 to 81,870) pg/dL. Using bivariate analysis, maternal age, race, marital status, utilization of public assistance, and mild or moderate to severe periodontal disease were associated with elevated serum 8-isoprostane. Using logistic regression, moderate to severe periodontal disease (adjusted odds ratio 2.9, 95% confidence interval: 1.7 to 5.0) remained significantly associated with an elevated serum 8-isoprostane level. Maternal periodontal disease is associated with oxidative stress during pregnancy. Further study is needed to determine the role of maternal oxidative stress in periodontal disease-associated adverse pregnancy outcomes.

Follicular-fluid anti-Müllerian hormone concentration is similar in patients with endometriosis compared with non-endometriotic patients

This cross-sectional prospective study assessed follicular-fluid anti-Müllerian hormone (AMH) concentrations in infertile patients with mild/minimal endometriosis during natural IVF. Thirty-two women participated in the study. Patients were divided into two groups: tubal obstruction without endometriosis (control group) and minimal/mild endometriosis (study group). All patients underwent laparoscopy for assessment of infertility; at the same time, any foci of endometriosis found were cauterized. AMH concentration was measured in the follicular fluid of a single follicle when it achieved pre-ovulatory maturation by ultrasensitive enzyme-linked immunosorbent assay. Likewise, AMH, FSH and inhibin B content in serum was also measured. Age (30 ± 1.3 and 32 ± 0.8 years) and body mass index (22 ± 0.6 and 22 ± 0.5 kg/m(2)), day-3 antral follicle count (11.3 ± 1.7 and 10.7 ± 1.5), serum FSH concentrations (5.4 ± 0.6 and 5.0 ± 0.3 IU/ml) and follicular-fluid AMH concentrations (1.8 ± 0.3 and 1.5 ± 0.1 ng/ml, study and control group, respectively; mean difference 0.33, 95% CI -0.21 to 0.88) were similar in both groups. This study shows that infertile patients with minimal/mild endometriosis have a similar concentration of AMH in the follicular fluid after natural IVF as compared with control subjects.