Measurement of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 after delayed separation of whole blood samples

Objectives:Epidemiological studies benefit from unbiased blood specimens collected with minimal cost and effort of blood collection and storage. We evaluated the stability of IGF-1 and IGFBP-3 in whole blood samples stored at room temperature to justify delays in blood processing.Design and methods:Total IGF-1 and IGFBP-3 levels were measured in EDTA plasma (n = 12), heparin plasma (n = 12) and serum (n = 10) samples of healthy volunteers after blood processing delays up till 14 days. Stability of measured IGF-1 and IGFBP-3 levels was tested by paired t-test and a linear mixed effect model.Results:Longitudinal analysis showed that IGF-1 levels were not significantly affected by blood processing delays in EDTA tubes (p = 0.18) and IGFBP-3 levels were marginally stable (p = 0.06). In heparin plasma and serum, however, IGF-1 increased over time of delayed processing and IGFBP-3 levels tended to decrease (p < 0.01).Conclusion:Total IGF-1 and IGFBP-3 levels are stable in whole blood collected in EDTA tubes at room temperature up till 7 days, allowing a delay in blood processing to reduce costs in large multi-center studies.     

Anti-centromere antibodies in a large cohort of systemic sclerosis patients: comparison between immunofluorescence, CENP-A and CENP-B ELISA

IntroductionAnti-centromere antibodies (ACA) are useful biomarkers in the diagnosis of systemic sclerosis (SSc) where they are found in 20–40% of patients and, albeit with lower prevalence, in patients with other systemic autoimmune rheumatic diseases. Historically, ACA were detected by indirect immunofluorescence (IIF) on HEp-2 cells and confirmed by immunoassays using recombinant CENP-B. During the last few years, to accommodate high throughput diagnostics, a number of laboratories changed from IIF to ELISA assays. The objective of this study was to compare the detection of ACA by IIF to CENP-A and a CENP-B ELISA in a large cohort of SSc patients.MethodsSera collected from SSc patients (n = 834) were tested for ACA by IIF on HEp-2 cells (ImmunoConcepts, Sacramento, CA) and CENP-A and CENP-B ELISA (both Dr. Fooke Laboratorien GmbH, Neuss, Germany). Furthermore, other autoantibodies were determined by QUANTA-Plex^TM SLE 8 profile (INOVA, San Diego, CA), QUANTA Lite® RNA Pol III (INOVA) and PM1-Alpha ELISA (Dr. Fooke).ResultsThe prevalence of ACA was 35.0% by IIF, 41.6% by CENP-A and 57.8% by CENP-B ELISA. When the CENP-A and the CENP-B ELISA results were compared to the IIF, the area under the curve value derived from receiver operating characteristic analysis was 0.98 for both assays. ACA and anti-topoisomerase I antibodies co-occurred in 1.2% (ACA by IIF), in 3.5% (by CENP-A ELISA) and in 7.4% (by CENP-B ELISA). Anti-CENP-A antibodies were negatively associated with anti-Scl-70, anti-RNA Pol III, (both p < 0.0001), anti-U1-RNP (p = 0.008) and anti-PM1-Alpha antibodies (p = 0.0337). The degree of association was dependent on the cut-off value used.ConclusionAlthough we found good agreement between IIF and ELISA for the detection of ACA in SSc, a significant portion of CENP ELISA positive sera did not show the typical ACA staining pattern. Based on these findings, we conclude that an IIF ACA negative result might not rule out the presence of ACA. In addition, new CENP ELISA kits are reliable for the detection of anti-CENP in SSc sera.     

Cytokine elevations in acute coronary syndrome and ovarian cancer: a mechanism for the up-regulation of the acute phase proteins in these different disease etiologies

Objectives:To identify if a common set of cytokines is elevated in both ovarian cancer and acute coronary syndrome (ACS).Design and methods:A cytokine array (Randox Ltd) was measured in healthy women (n = 33), women with ACS (n = 21) and ovarian cancer (n = 45).Results:Women with ACS or ovarian cancer had higher concentrations of IL-6, IL-8, VEGF, MCP-1, and EGF as compared to healthy volunteers.Discussion:Common cytokine elevations are present in both ACS and ovarian cancer.     

Normal range of serum Amphiregulin in healthy adult human females

ObjectivesPrior to large studies in breast cancer patients, we have sought to establish the normal range of a potential serum biomarker, Amphiregulin, in healthy women and to determine whether sampling during the menstrual cycle influences the detected Amphiregulin levels.Design and methodsSerum Amphiregulin levels were quantified using a commercially available ELISA in 85 normal female donors.ResultsThe range of circulating Amphiregulin was 0–4467 pg/mL. The majority of women had no detectable circulating Amphiregulin (n = 54), and only five women had levels exceeding 500 pg/mL. Serum Amphiregulin levels did not vary significantly during the menstrual cycle (n = 7 women).ConclusionsDetection of circulating Amphiregulin in a significant minority of healthy women suggests that it may not have the specificity necessary for a population screening tool; however its potential utility for monitoring response to treatment or disease progression should be examined in breast cancer cases.     

Enzyme-linked immunosorbent assay (ELISAs) for metalloproteinase derived type II collagen neoepitope, CIIM--increased serum CIIM in subjects with severe radiographic osteoarthritis

ObjectivesIn joint degenerative diseases, the collagens are degraded by matrix metalloproteinases and protein fragments are released to serum as potential biomarkers.MethodsA collagen type II specific neoepitope, CIIM, was identified (…RDGAAG¹⁰⁵³) by mass spectrometry. Two ELISAs against the neoepitope were developed. CIIM was measured in cartilage explants in the presence or absence of protease inhibitors. CIIM was measured in OA synovial fluid (n = 51) and serum (n = 156). Knee OA was graded by standard Kellgren–Lawrence (KL) score.ResultsThe ELISAs showed good technical performance; CV%, < 13%. CIIM release from cartilage explants was blocked by the MMP inhibitor. CIIM was detected in synovial fluid. Furthermore, serum CIIM levels were significantly higher (P < 0.05) in those individuals with mild or severe OA than in those with no OA.ConclusionWe developed a new biomarker for joint degenerative diseases, which we demonstrated was derived from MMP-degraded type II collagen.     

Soluble receptor for advanced glycation end products (sRAGE) in plasma and synovial fluid is inversely associated with disease severity of knee osteoarthritis

Objectives:The aim of this study was to measure soluble receptor for advanced glycation end products (sRAGE) in plasma and synovial fluid of knee osteoarthritis (OA) patients and to determine the correlation between sRAGE levels and disease severity.Design and methods:Thirty-six OA patients and 15 healthy controls were enrolled in this study. OA grading was performed using the Kellgren–Lawrence classification. sRAGE levels in plasma and synovial fluid were analyzed by enzyme-linked immunosorbent assay.Results:Plasma sRAGE levels were significantly lower in OA patients than in healthy controls (P = 0.01). sRAGE levels in plasma were remarkably higher with regard to paired synovial fluid (P = 0.001). Additionally, sRAGE concentrations in plasma and synovial fluid showed significant inverse correlation with disease severity (r = ?0.65, P < 0.001 and r = ?0.55, P = 0.001, respectively). Further analysis showed that there was a strong positive correlation between plasma and synovial sRAGE concentration (r = 0.81, P < 0.001).Conclusions:sRAGE levels were significantly lower in OA patients compared with controls, and sRAGE levels in plasma and synovial fluid also decreased significantly as the disease severity increased. Accordingly, sRAGE levels could be used as a biochemical marker for assessing the severity and progression of knee OA.     

Lipid, protein, DNA oxidation and antioxidant status in rheumatoid arthritis

ObjectivesTo investigate lipid, protein, DNA oxidation and antioxidant status in blood and synovial fluid of rheumatoid arthritis (RA) patients and to determine the importance of oxidative stress parameters in reflecting disease activity.Design and methods20 RA patients and 15 healthy controls were included. Lipid peroxidation (thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide, and conjugated diene), protein oxidation (carbonyl and thiol), DNA oxidation (8-OHdG) and antioxidant status markers (glutathione (GSH), glutathione peroxidase (GSH Px), superoxide dismutase (CuZn SOD), and catalase) were determined in blood and synovial fluid.ResultsTBARS (p < 0.001), lipid hydroperoxide (p < 0.001), conjugated diene (p < 0.001), carbonyl (p < 0.001) and 8-OHdG (p < 0.01) levels were significantly higher; thiol (p < 0.01) and GSH levels (p < 0.01) and GSH Px (p < 0.001) and CuZn SOD (p < 0.01) activities were significantly lower in blood of RA patients. TBARS (p < 0.001), lipid hydroperoxide (p < 0.001), conjugated diene (p < 0.01), carbonyl (p < 0.001) and 8-OHdG (p < 0.05) levels were significantly higher, catalase activity (p < 0.001) significantly lower in synovial fluid of RA patients.ConclusionsIncreased lipid, protein and DNA oxidation markers and impaired antioxidant status confirm the role of oxidative stress in the pathogenesis of RA. Lipid peroxidation markers can serve as surrogate markers for disease activity.     

A multiplex immunoassay gives different results than singleplex immunoassays which may bias epidemiologic associations

ObjectivesMultiplex immunoassays are increasingly used in epidemiologic studies to measure inflammatory factors, however there are few published evaluations of this technology. Our objective was to compare a common multiplex immunoassay to singleplex immunoassays for measuring inflammatory factors, and to examine how combining data from each affects an epidemiologic association.Design and methodsPlasma IL-1 beta, IFN-gamma, IL-6, and TNF-alpha were measured in 100 samples using a multiplex kit from Mesoscale Discovery (MSD) and singleplex ELISAs from R&;D Systems. Separate samples (n = 80) were collected to compare multiplex and singleplex assays from MSD. We simulated the effect of combining MSD multiplex and R&;D singleplex data on the association between sugar sweetened beverage (SSB) intake and IL-6 in the Health Professionals Follow-up Study (HPFS; n = 1314).ResultsCompared to R&;D ELISAs, the MSD multiplex proportionally and significantly overestimated IL-1 beta (slope = 1.2), and IFN-gamma (slope = 2.9) but underestimated IL-6 (slope = 0.5). Correlations were ≥ 0.81 except for TNF-alpha (r = 0.31). Compared to MSD singleplex, the MSD multiplex proportionally underestimated IFN-gamma (slope = 0.7) and TNF-alpha (slope = 0.5). Correlations were ≥ 0.96. The association between sugar sweetened beverage intake and IL-6 in the HPFS (+ 0.16 pg/mL per serving/day, p = 0.02, all singleplex) was gradually attenuated as multiplex data made an increasing contribution to the data-set. (+ 0.09 pg/mL [? 45%], p = 0.02, all multiplex)ConclusionsA multiplex immunoassay for inflammatory factors yielded significantly different results than singleplex immunoassays—including those from the same company. Correlations were not consistently high, except among assays from the same company. Such differences may distort epidemiologic relationships if data from both methods are merged.     

Elevated circulatory MMP-2 and MMP-9 levels and activities in patients with rheumatoid arthritis and systemic lupus erythematosus

ObjectivesMatrix metalloproteinases (MMPs) are suggested to play important roles in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This study is to examine the MMPs expressions and activities in Taiwanese RA and SLE patients.Design and methodsLevels and activities of plasma MMP-2 and MMP-9 were investigated by enzyme-linked immunosorbent assay and zymography, respectively.ResultsMMP-2 levels in control subjects, RA and SLE patients were 146.1 ± 34.2, 194.0 ± 24.2 and 208.9 ± 75.9 ng/mL respectively, and for MMP-9 were 51.4 ± 57.1, 567.7 ± 313.1 and 208.7 ± 105.5 ng/mL respectively. Both MMP-2 and MMP-9 levels and activities from all patients were significantly higher than that from control subjects.ConclusionsMMP-2 levels in both patients groups were approximately 1.3–1.4 folds higher than that in control subjects, notably, MMP-9 levels were 11- and 4-folds significantly higher, respectively, in RA and SLE patients. The results which MMP-2 and MMP-9 levels and activities are significantly elevated support the involvement of MMPs proteins in these autoimmune disorders.     

Mitochondrial depolarisation and oxidative stress in rheumatoid arthritis patients

ObjectivesTo investigate mitochondrial membrane integrity, lipid peroxidation and cytotoxicity in peripheral lymphocytes (PL) from rheumatoid arthritis (RA) patients.Design and methodsSouth African black RA patients (HIV^?) were recruited into the study. Mitochondrial membrane potential (Δψ_m) was analysed in PL using the JC-1 dye distribution assay and flow cytometry. Correlations between Δψ_m and clinical parameters were tested for statistical significance. Cytotoxicity (LDH) and lipid peroxidation (thiobarbituric acid reactive substances (TBARS)) was also determined.ResultsOur findings show significantly elevated levels of cytotoxicity (p = 0.0029) and lipid peroxidation (p = 0.0030) in RA. A significantly higher percentage of circulating PL contained depolarised mitochondria (p = 0.0003) which correlated with disease activity and C-reactive protein levels in patients. Collapse of Δψ_m also negatively correlated to absolute lymphocyte counts (r = ? 0.4041; p = 0.0197).ConclusionThese findings suggest a possible role for mitochondrial membrane alterations in the pathology of RA.     

Comparative study between anion-exchange HPLC and homogeneous assay methods in regard to the accuracy of high- and low-density lipoprotein cholesterol measurement

Objectives:A convenient method based on anion-exchange HPLC was recently developed to determine cholesterol levels of lipoproteins (HDL, LDL, IDL, VLDL, and chylomicron). The present study was performed to compare this HPLC method to homogenous assay in regard to measurement accuracy of HDL and LDL cholesterol.Design and methods:Serum samples (n = 105), including three samples from cholestasis patients, were measured by homogenous assay with Cholestest-LDL and CholestestN-HDL (Daiichi Chemicals, Tokyo) and by HPLC as reported previously (J Lipid Res 2003; 44: 1404–12).Results:The homogenous assay for HDL cholesterol correlated strongly with the HPLC method for HDL cholesterol (r = 0.976). Two samples from cholestasis patients could not be measured by homogenous assay but were measured by HPLC. The homogenous assay for LDL cholesterol correlated modestly with the HPLC method for LDL cholesterol (r = 0.823). Three outlier samples, from cholestasis patients with serum cholesterol levels > 17 mmol/L, were observed in this correlation analysis. Homogenous assay data showed that these LDL cholesterol levels were 15.2–34.7 mmol/L. However, HPLC data showed that these LDL cholesterol levels were 3.6–8.2 mmol/L, and that the major lipoprotein fractions were VLDL and IDL. The difference in LDL cholesterol levels (homogenous assay data minus HPLC data) was positively correlated with VLDL cholesterol levels.Conclusions:When measuring samples from cholestasis patients, homogenous assay may give inaccurate results. In contrast, the HPLC method is likely to be capable of accurately measuring HDL and LDL cholesterol levels without the involving VLDL.     

Serum brain-derived neurotrophic factor in patients with type 2 diabetes mellitus: Relationship to glucose metabolism and biomarkers of insulin resistance

ObjectivesThe aims of this study were to measure serum levels of brain-derived neurotrophic factor (BDNF) in patients with type 2 diabetes mellitus (T2DM) and to investigate the association of these BDNF levels with biomarkers of glucose metabolism and insulin resistance.Design and methodsWe studied 112 patients with T2DM and 80 age- and gender-matched control subjects.ResultsSerum BDNF levels were significantly lower in patients with T2DM compared to control subjects (15.5 ± 5.2 ng/mL vs. 20.0 ± 7.3 ng/mL, P < 0.01). In patients with T2DM, BDNF levels were significantly higher in females than in males (P < 0.01). In the female patients, BDNF was positively related to immunoreactive insulin (IRI) (ρ = 0.458, P < 0.05) and HOMA-R (ρ = 0.444, P < 0.05). Stepwise multiple regression analysis showed a significant relationship between BDNF and IRI (F = 5.294, P < 0.05) in female patients with diabetes.ConclusionsThese findings suggest that BDNF may contribute to glucose metabolism.     

The alarm secretory leukocyte protease inhibitor increases with progressive metabolic dysfunction

BackgroundSecretory leukocyte protease inhibitor (SLPI) is an alarm antiprotease secreted by neutrophils and mucous membranes that potently inhibits the inflammatory cascade; however, the role of SLPI in human disease remains largely unknown. We hypothesized that SLPI is related to chronic low-grade inflammatory diseases, such as metabolic syndrome (MS) or type-2 diabetes (T2DM).MethodsWe examined associations between circulating SLPI (ELISA) and quantitative traits of MS (ATPIII criteria) in 261 Caucasian men with various degrees of metabolic dysfunction. Subjects had neither MS nor T2DM (n = 140), either diagnosis (n = 44) or both diagnoses (n = 77).ResultsCirculating SLPI increased with progressive metabolic dysfunction, with a mean increase of 4.4 ng/ml (95% IC 2.4 to 6.3 ng/ml; p < 0.001) for each unit increase in the criteria used to define MS. Circulating SLPI showed independent associations with uric acid [β = 5.1 (95% CI 3.4 to 6.7), p < 0.00001], serum lipids, pulse pressure and inflammatory markers.ConclusionsCirculating SLPI increases with progressive metabolic dysfunction and is related to metabolic and inflammatory parameters in men.     

Increased urinary level of oxidized nucleosides in patients with mild-to-moderate Alzheimer's disease

Objective:Oxidative stress may play an important role in the pathogenesis of Alzheimer's disease (AD).Design and methods:To investigate the possible role of oxidative DNA damage in the pathogenesis of AD, we measured the metabolite concentrations of oxidized nucleosides (pseudouridine, 1-methyladenosine, 5-methylcytidine, 5-methyl-2′-deoxycytidine, 3-methyluridine, N², N²-dimethylguanosine, 8-hydroxy-2′-deoxyguanosine, 5-deoxyadenosine and 2-deoxyguanosine) in urine between AD (n = 36) and control subjects (n = 34) using liquid chromatography-mass spectrometry (LC-MS) without urine preparation.Results:In AD, the 3-methyluridine, 1-methyladenosine, 8-hydroxy-2′-deoxyguanosine (p < 0.05, respectively), 2-deoxyguanosine (p < 0.01) and pseudouridine, N², N²-dimethylguanosine (p < 0.001, respectively) were significantly increased when compared with the control subjects.Conclusion:The results indicate that oxidized urinary nucleosides may be useful as biomarkers for AD in early stages.     

Correlations of six related pyrimidine metabolites and diabetic retinopathy in Chinese type 2 diabetic patients

BackgroundDiabetic retinopathy (DR), a kind of diabetic microvascular complication, is the leading cause of visual impairment in adults aged 30 to 65 years. Despite rapid research progress, robust predictors to assess prospectively with high precision the risk for DR in individuals with diabetes are still lacking. We investigated the relationship between pyrimidine metabolites and disease, and find out the potential biomarkers for diagnosis.MethodsThe study group consisted of 116 subjects who were divided to 3 groups: control (n = 41), type 2 diabetes without retinopathy (DM, n = 37), and with retinopathy (DR, n = 38). Biochemical and clinical parameters, concentrations of related metabolites, including of cytosine, cytidine, uridine, thymine, thymidine and 2′-deoxyuridine were measured in plasma of all participants.ResultsThere was a significant increase of concentrations of cytosine (p = 0.010), cytidine (p < 0.001) and thynidine (p < 0.001) with DR compared to DM. The concentration of uridine, thymine and 2′-deoxyuridine did not change.ConclusionsThe concentrations of cytosine, cytidine and thynidine may be useful for monitoring the progression of DR and evaluating the treatment. And cytidine has good sensitivity and specificity for diagnosis.     

Validation of a simple method of estimating plasma free cortisol: role of cortisol binding to albumin

Objectives:To develop, optimize, and validate a generalized mass action, equilibrium solution that incorporates measured concentrations of albumin as well as cortisol binding globulin (CBG) to estimate free cortisol.Design and methods:Free cortisol was estimated by Coolens method or by cubic equilibrium equation and compared to measured free cortisol, determined by ultrafiltration method, in subjects with septic shock (n = 45), sepsis (n = 19), and healthy controls (n = 10) at 0, 30, and 60 min following administration of cosyntropin (250 mcg). The data set also included repeat testing in 30 subjects following recovery from sepsis/septic shock. The equilibrium dissociation constant for cortisol binding to albumin (K_A) was optimized by non-linear regression. The cubic equilibrium solution was also used to model the influence of cortisol, CBG, and albumin concentration on free cortisol.Results:Compared to measured free cortisol, the cubic solution, using an optimized K_A of 137,800 nM, was less biased than Coolens solution, with mean percent error of ? 23.0% vs. ? 41.1% (paired t test, P < 0.001). Standard deviation values were also significantly lower (Wilks' test, P < 0.001) for the cubic solution (SD 35.8% vs. 40.8% for cubic vs. Coolens, respectively). Modeling studies using the cubic solution suggest an interaction effect by which low concentrations of CBG and albumin contribute to a greater increase in free cortisol than the sum of their independent effects.Conclusions:Mass action solutions that incorporate the measured concentration of albumin as well as CBG provide a reasonably accurate estimate of free cortisol that generalizes to conditions of health as well as a setting of hypercortisolism and low CBG and albumin concentrations associated with septic shock. Modeling studies emphasize the significant contribution of albumin deficiency and albumin-bound cortisol under conditions of CBG-deficiency, and identify a synergistic effect by which combined CBG and albumin deficiency contribute to elevation of free cortisol in septic shock.     

Evaluation of circulating vascular endothelial growth factor and soluble adhesion molecules as reliable predictors of native arteriovenous fistula thrombosis in chronic hemodialysis patients

ObjectivesWe evaluated the possibility of using circulating vascular endothelial growth factor (VEGF) and soluble adhesion molecules as reliable predictors of native arteriovenous (AV) fistula thrombosis in chronic hemodialysis (HD) patients.Design and methodsThis study included 62 HD patients (34 with thrombosed and 28 with non-thrombosed AV fistulas) and 21 healthy volunteers. Serum VEGF, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble E-selectin (sE-selectin) were measured using ELISA technique.ResultsVEGF, sVCAM-1, sICAM-1 and sE-selectin median levels were higher in HD patients compared to controls (p = 0.000 for all parameters). Increased median levels of VEGF and sVCAM-1 were demonstrated in HD patients with thrombosed AV fistulas compared to HD patients with non-thrombosed AV fistulas (p = 0.003 and 0.000, respectively). A significant positive correlation has been found between VEGF and sVCAM-1 in HD patients with thombosed AV fistulas (r = 0.525, p = 0.001).ConclusionsThe assessment of serum VEGF and sVCAM-1 might be useful for the identification of the chronic HD patients at an increased risk for native AV fistulas thrombosis. The clinical relevance of these observations warrants further investigations.     

Association between serum cortisol and testosterone levels, opioid therapy, and symptom distress in patients with advanced cancer

ContextPatients with advanced cancer often experience symptoms such as pain, anorexia, and fatigue. Opioid therapy for the management of cancer pain may result in neurohormonal dysfunction that may contribute to a patient’s symptom burden.ObjectivesTo examine the association between serum cortisol and testosterone levels, opioid therapy, and symptom distress in patients with cancer.MethodsA retrospective chart review was performed on 77 consecutive patients with advanced cancer referred for symptoms of fatigue or cachexia. We collected information regarding cortisol levels (am or random), testosterone levels (men only), morphine equivalent daily dose (MEDD), and symptom severity measured by the Edmonton Symptom Assessment Scale. Nonparametric correlation analysis was performed.ResultsThe median age was 63 years (range 24–79), and 62% were men (n = 48). Most patients had gastrointestinal (n = 33, 43%) or thoracic (n = 21, 27%) malignancies and were Caucasian (n = 46, 60%). The median random cortisol level was 19.1 μg/dL (Q1–Q3, 13.4–23.8 [normal, 4.3–22.4]), which correlated with MEDD (Spearman coefficient, 0.25, P = 0.032) and symptoms including pain (0.50, P < 0.001), fatigue (0.29, P = 0.012), nausea (0.34, P = 0.003), depression (0.24, P = 0.032), and anxiety (0.25, P = 0.031). Pain and nausea remained significant after Bonferroni correction. Median morning cortisol level (n = 28) was 20.6 μg/dL (Q1–Q3, 16.6–25.4) and significantly correlated with pain (0.55, P = 0.003) after Bonferroni correction. Patients with a MEDD <30 mg/day had a mean random cortisol level of 16.6 μg/dL, whereas patients with a MEDD ≥30 mg/day had a mean random cortisol level of 20.6 μg/dL (P = 0.01). In 44 male patients with cancer, MEDD was inversely correlated with the total testosterone level (?0.52, P = 0.001).ConclusionIn patients with advanced cancer, elevated random cortisol levels were associated with pain and opioid use, although abnormally low levels of cortisol were found to be infrequent. Patients on higher opioid therapy (MEDD >30) had increased cortisol levels, and male patients had lower testosterone levels. Our study suggests that opioid therapy in patients with advanced cancer may inhibit gonadal function while sparing the adrenal axis. Future studies are needed.     

Performance evaluation of Siemens ADVIA Centaur enhanced estradiol assay and a split sample comparison with liquid chromatography-tandem mass spectrometry

ObjectivesThe objective of this study was to evaluate the newly developed Siemens ADVIA Centaur® enhanced Estradiol (eE2) assay and compare it with a well-established estradiol liquid chromatography-tandem mass spectrometry (LC-MS/MS) method.Design and methodsThe Siemens eE2 assay was evaluated using the Clinical and Laboratory Standards Institute evaluation protocols. Split patient samples were compared with the eE2 assay, the current ADVIA Centaur E2-6 Ill assay; and LC-MS/MS method by API5000 mass spectrometer.ResultsWithin-run and total imprecision of the eE2 assay demonstrated coefficient of variations of 5.7%, 3.2%, 1.5%, and 10.4%, 7.3%, and 6.8%, at levels of 380, 752, and 2051 pmol/L, respectively. The method comparisons showed: eE2 = 0.903(E2-6 III) –16.2, R² = 0.938, average bias = ? 12.3%; and eE2 = 0.946(LC-MS/MS) + 19.5, R² = 0.925, average bias: 0%.ConclusionThe Siemens eE2 assay correlates well with LC-MS/MS. This method is reliable, and appropriate for routine clinical laboratory use.     

Oxidative modification of patient's plasma proteins and its role in pathogenesis of multiple sclerosis

BackgroundOxidative stress plays an important role in multiple sclerosis (MS).Objective and methodsThe present study was designed to evaluate the modifications of plasma proteins by estimation markers of oxidative/nitrosative stress: carbonyl groups and 3-nitrotyrosines (3-NT) levels in relapsing-remitting (RR) (n = 10) and secondary progressive (SP) (n = 10) clinical course of multiple sclerosis. Moreover, we estimated the level of uric acid (UA) in plasma of MS patients.ResultsCompared to controls (n = 10), the levels of carbonyl groups in plasma proteins were elevated (P < 0.0001) as well in RRMS as in SPMS. The highest concentration of 3-NT was observed in plasma proteins obtained from SPMS patients (P < 0.0005). The level of uric acid in plasma was significantly lower in RRMS (P < 0.0001) than SPMS.ConclusionThis is the first report which presented differences between SPMS and RRMS patients in 3-NT and protein carbonyl groups in plasma proteins.