Bone turnover markers, BMD and TBS after short-term, high-dose glucocorticoid therapy in patients with Graves' orbitopathy: a small prospective pilot study.

PURPOSE: Chronic GC administration has numerous side effects, but little is known about the side effects of their short-term use (< 3 months)-particularly, when high doses are involved, as in the treatment of Graves' orbitopathy (GO). We investigated the effects of short-term, high-dose GC on bone turnover markers, bone mineral density (BMD), and trabecular bone scores (TBS). METHODS: Eleven patients (10 females and 1 male; median age 56 years) with active GO who were candidates for treatment with intravenous (iv) methylprednisone were consecutively enrolled. All patients were pretreated with a loading dose of 300,000 units of cholecalciferol, then given a median cumulative dose of 4.5 g (range 1.5-5.25 g) iv methylprednisone. Biochemical parameters of bone metabolism (25OHD3, PTH, P1NP, CTX and bALP) were measured at the baseline, and then 1 week and 1, 3, 6 and 12 months. BMD and TBS were obtained by X-ray absorptiometry (DXA) at the baseline and at 6 and 12 months. On DXA image, morphometric vertebral fracture assessment (VFA) was done. RESULTS: There were no significant changes in PTH, bALP or P1NP. A significant drop in CTX was seen at 1 month (down Δ49.31% from the baseline, p = 0.02), with a return to the baseline at the 3-month measurement. There was a moderate (not significant), but persistent reduction in P1NP. No changes in BMD or TBS came to light. No vertebral fractures were documented. CONCLUSIONS: Short-term, high-dose GC treatment caused a rapid, transient suppression of bone resorption, with no effects on BMD or bone micro-architecture (TBS).

Intrathecal K free light chain synthesis in multiple sclerosis at clinical onset associates with local IgG production and improves the diagnostic value of cerebrospinal fluid examination.

BACKGROUND: The pathological significance and the diagnostic usefulness of intrathecal κ and λ free light chain (FLC) synthesis in Multiple Sclerosis (MS) are debated. METHODS: Paired cerebrospinal fluid (CSF) and serum specimens from 70 relapsing remitting MS (RRMS), 40 with and 30 without CSF restricted IgG Oligoclonal Band (IgGOB), and 37 from healthy controls (HC) were analyzed. IgG, IgM, κFLC and λFLC concentrations and indexes were evaluated. All RRMS performed MRI to estimate white and grey matter (WM) pathology. RESULTS: In HC, no intrathecal κ or λ FLC synthesis was found, and κFLC and λFLC Indexes were reciprocally correlated (r = 0.67, p < 0.001). In RRMS, intrathecal κFLC or λFLC synthesis was demonstrated in respectively 66% and 43% of the cases, the Qκ/λ ratio was significantly higher compared to HC (17.0 ±â€¯31.3 vs 0.79 ±â€¯0.20, p < 0.001) and the correlation between κFLC Index and λFLC Index was weak (r:0.38, p < 0.05). Intrathecal IgG synthesis was associated with κFLC Index (IgG Index: r2 = 0.53, ß = 0.73, p < 0.001; IgGLOC: r2 = 0.37, ß = 0.61, p < 0.001; IgGIF: r2 = 0.69, ß = 0.83, p < 0.001), but not with λFLC Index, while intrathecal IgM synthesis correlated with λFLC Index (IgM Index: r = 0.41, p < 0.001; IgMLOC: r = 0.34, p < 0.005; IgMIF: r = 0.45, p < 0.001), but not with κFLC Index. 26% of RRMS patients without CSF-restricted IgGOB had increased κFLCLOC. Finally, no associations were observed between any CSF and MRI parameters. CONCLUSIONS: The demonstration of intrathecal κFLC synthesis may further improve the diagnostic usefulness of CSF examination in RRMS. The marked increased in Qκ/λ further suggests a deregulated B-cell activation in MS pathology.

Biomarkers, imaging and disease activity indices in patients with early axial spondyloarthritis: the Italian arm of the SpondyloArthritis-Caught-Early (SPACE) Study.

The study aimed to evaluate biomarkers facilitating early diagnosis of axial spondyloarthritis (axSpA) and correlations between them and disease activity parameters and imaging indexes. Patients with low back pain (LBP) (≥3 months, ≤2 years, onset ≤45 years) participating in the Italian arm of the SpondyloArthritis-Caught-Early SPACE study underwent a physical examination, questionnaires, laboratory tests, X-rays and MRI of the spine and sacroiliac joints (SIJ). An expert rheumatologist formulated axSpA diagnosis in accordance with Assessment of SpondyloArthritis International Society (ASAS) criteria. Disease activity and physical functioning were assessed using imaging, clinical and serological indices. Spine and SIJ MRI and X-rays were scored independently by 2 readers using the SPARCC, mSASSS and NY-criteria. Patients were classified as: subjects with signs of radiographic sacroiliitis (r-axSpA), subjects with signs of sacroiliitis on SIJ-MRI but not on X-rays (nr-axSpA MRI SIJ+) or subjects with no signs of sacroiliitis on MRI/X-rays but with >2 SpA features and signs of bone oedema on MRI spine (nr-axSpA MRI SIJ-/undifferentiated SpA). Significant differences were found in the prevalence of radiographic sacroiliitis, active sacroiliitis on MRI and SPARCC SIJ scores. Biomarker levels were not significantly increased in any of the patient groups. The correlations between IL-17 and IL-23 and other indices were not significant; correlations were found between IL-22 and BASFI, BASG1, HAQ, VAS pain, between mSASSS and MMP3, and between the latter and hsCRP. Although not significantly higher in any of the three groups, IL-22, MMP3 and hsCRP values were correlated with some disease activity indexes and with mSASSS. Large observational studies are required to confirm these preliminary findings.

Diagnostic and prognostic value of low percentage of glycosylated ferritin in acquired hemophagocytic lymphohistiocytosis: A single-center study.

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is an aggressive and life-threatening syndrome characterized by an excessive immune activation. Glycosylated ferritin (GF) level has been proposed as highly specific of HLH. METHODS: We have studied 12 subjects with HLH according to the HLH-04 trial criteria and 11 patients with a clinical and laboratoristic suspicion of HLH. The percentage of GF was measured by an in-house assay. RESULTS: The only biomarkers that were significantly different in the two groups were fraction of GF (P<.001) and the presence of hemophagocytosis in bone marrow (P=.006). Subjects with HLH had significantly lower percentage of GF than patients with other inflammatory conditions mimicking HLH. A fraction of GF ≤20% was strongly consistent with a diagnosis of HLH. CONCLUSIONS: Fraction of GF is useful to identify subjects at high risk for early death and therefore in need of early treatment.

Mannose-binding lectin 2 (Mbl2) gene polymorphisms are related to protein plasma levels, but not to heart disease and infection by Chlamydia.

The presence of the single nucleotide polymorphisms in exon 1 of the mannose-binding lectin 2 (MBL2) gene was evaluated in a sample of 159 patients undergoing coronary artery bypass surgery (71 patients undergoing valve replacement surgery and 300 control subjects) to investigate a possible association between polymorphisms and heart disease with Chlamydia infection. The identification of the alleles B and D was performed using real time polymerase chain reaction (PCR) and of the allele C was accomplished through PCR assays followed by digestion with the restriction enzyme. The comparative analysis of allelic and genotypic frequencies between the three groups did not reveal any significant difference, even when related to previous Chlamydia infection. Variations in the MBL plasma levels were influenced by the presence of polymorphisms, being significantly higher in the group of cardiac patients, but without representing a risk for the disease. The results showed that despite MBL2 gene polymorphisms being associated with the protein plasma levels, the polymorphisms were not enough to predict the development of heart disease, regardless of infection with both species of Chlamydia.

25-Hydroxycholecalciferol response to single oral cholecalciferol loading in the normal weight, overweight, and obese.

UNLABELLED: After a single cholecalciferol load, peak serum 25-hydroxycholecalciferol (25OHD) is lower in individuals with a higher body mass index (BMI), probably due to it being distributed in a greater volume. Its subsequent disappearance from the serum is slower the higher the individual's BMI, probably due to the combination of a larger body volume and a slower release into the circulation of vitamin D stored in adipose tissue. INTRODUCTION: The aim of the study is to examine 25-hydroxycholecalciferol (25OHD) response to a single oral load of cholecalciferol in the normal weight, overweight, and obese. METHODS: We considered 55 healthy women aged from 25 to 67 years (mean ± SD, 50.8 ± 9.5) with a BMI ranging from 18.7 to 42 kg/m(2) (mean ± SD, 27.1 ± 6.0). The sample was divided into three groups by BMI: 20 were normal weight (BMI ≤ 25 kg/m(2)), 21 overweight (25.1 ≤ BMI ≤ 29.9 kg/ m(2)), and 14 obese (BMI ≥ 30 kg/m(2)). Each subject was given 300,000 IU of cholecalciferol orally during lunch. A fasting blood test was obtained before cholecalciferol loading and then 7, 30, and 90 days afterwards to measure serum 25OHD, 1,25 dihydroxyvitamin D [1,25 (OH)2D], parathyroid hormone (PTH), calcium (Ca), and phosphorus (P). Participants' absolute fat mass was measured using dual energy X-ray absorptiometry (DEXA). RESULTS: The fat mass of the normal weight subjects was significantly lower than that of the overweight, which in turn was lower than that of the obese participants. Serum 25OHD levels increased significantly in all groups, peaking 1 week after the cholecalciferol load. Peak serum 25OHD levels were lower the higher the individuals' BMI. After peaking, the 25OHD levels gradually decreased, following a significantly different trend in the three groups. The slope was similar for the overweight and obese, declining significantly more slowly than in the normal weight group. In the sample as a whole, there was a weakly significant negative correlation between fat mass and baseline 25OHD level, while this correlation became strongly significant at all time points after cholecalciferol loading. CONCLUSIONS: The lower peak 25OHD levels seen in the obese and overweight is probably due to the cholecalciferol load being distributed in a larger body volume. The longer persistence of 25OHD in their serum could be due to both their larger body volume and a slower release into the circulation of the vitamin D stored in their adipose tissue.

Mannose-binding lectin 2 (Mbl2) gene polymorphisms are related to protein plasma levels, but not to heart disease and infection by Chlamydia

The presence of the single nucleotide polymorphisms in exon 1 of the mannose-binding lectin 2 (MBL2) gene was evaluated in a sample of 159 patients undergoing coronary artery bypass surgery (71 patients undergoing valve replacement surgery and 300 control subjects) to investigate a possible association between polymorphisms and heart disease with Chlamydia infection. The identification of the alleles B and D was performed using real time polymerase chain reaction (PCR) and of the allele C was accomplished through PCR assays followed by digestion with the restriction enzyme. The comparative analysis of allelic and genotypic frequencies between the three groups did not reveal any significant difference, even when related to previous Chlamydia infection. Variations in the MBL plasma levels were influenced by the presence of polymorphisms, being significantly higher in the group of cardiac patients, but without representing a risk for the disease. The results showed that despite MBL2 gene polymorphisms being associated with the protein plasma levels, the polymorphisms were not enough to predict the development of heart disease, regardless of infection with both species of Chlamydia.

Effect of a single injection of testosterone enanthate on 17ß estradiol and bone turnover markers in hypogonadal male patients.

PURPOSE: Several clinical studies testify the critical role played by estrogens in male bone metabolism. The aim of our study is to assess the effect of a single injection of testosterone enanthate in a group of hypogonadal men on 17ß estradiol serum levels and some bone metabolic parameters. METHOD: Twenty-one hypogonadal males were given one testosterone enanthate injection (250 mg). Blood samples were drawn before the injection and after 1, 2 and 3 weeks. The following variables were measured: Total testosterone (TT), 17ß estradiol (17ß E2), Sex hormone binding globulin, total alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen (CTx). RESULTS: After testosterone injection, both TT and 17ß E2 increased, peaking 1 week after the injection. Individual observation of the response of 17ß E2 to testosterone showed that a subgroup (n = 9) failed to respond with any increase in 17ß E2 at any of the weekly tests (group E2-), while the remainder (n = 12) showed a significant increase in 17ß E2, which reached a mean value three times higher than at baseline (group E2+). The E2- patients reached a TT peak lower than that observed in the E+ group. CTx serum levels declined progressively in the E2+ group, reaching the significance (p = 0.03) at the end of the study, while it did not change in E- group. CONCLUSION: This study suggests that a single injection of testosterone might have different effects on the production of endogenous estrogens, and a significant reduction of bone resorption parameters takes place only in the patients who show a significant increase of 17ß estradiol in response to testosterone administration.

Impact of hypertension on vascular remodeling in patients with psoriatic arthritis.

We studied the impact of hypertension along with traditional and new cardiovascular risk factors on the structural and functional properties of arteries in psoriatic arthritis (PsA) patients. We examined 42 PsA subjects (aged 51±9 years) stratified according to hypertensive status (19 normotensive, PsA-NT and 23 hypertensives, PsA-HT). Thirty-eight normotensive subjects (C-NT) and 23 hypertensives (C-HT) comparable by age and sex served as controls. Mean carotid intima-media thickness (mean-IMT) and mean of the maximum IMT (M-Max) were evaluated by ultrasound in carotid artery segment bilaterally. Post-occlusion flow-mediated dilation (FMD) of the brachial artery was evaluated by ultrasonography. These parameters were correlated with risk factors, markers of inflammation and disease activity. Values of mean-IMT were higher in both groups of PsA patients compared with C-NT (0.68 mm in PsA-NT and 0.75 mm in PsA-HT versus 0.61 mm in C-NT). PsA-HT displayed higher M-Max (0.95 mm) versus both C-HT (0.71 mm) and PsA-NT (0.79 mm). FMD was impaired in PsA subjects compared with C-NT (5.7% in PsA-NT and 6.0% PsA-HT versus 9.3% in C-NT), whereas there was no difference among PsA-HT, PsA-NT, and C-HT groups. Values of carotid IMT were directly related to tumor necrosis factor (TNF)-α, osteoprotegerin (OPG), blood pressure and lipid profile levels. FMD showed an inverse relationship with TNF-α and blood pressure, but no correlation with lipids. In conclusion, PsA per se implies a pro-atherogenic remodeling, which is enhanced by the hypertensive status. TNF-α and OPG may have an independent role in the development of such vascular damage.

An integrated system for monitoring the quality of sample transportation.

OBJECTIVES: Due to the consolidation of laboratory testing facilities, there is an increasing need for systems able to assure quality and safety in biological sample transportation, although little evidence on this aspect is available in literature. DESIGN AND METHODS: An integrated system for sample transportation, implemented and monitored over a five-year period by our team, consists of secondary and tertiary containers, a device for temperature and time recording, and a system manager allowing the acceptance or rejection of biological samples through the immediate visualization and validation of registered data. RESULTS: Data collected between 2009 and October 2011, after a preliminary phase for optimizing the temperature inside the containers, demonstrated the frequency of transportations at an acceptable temperature (<20 °C) had increased and that of transportations at an excessively high temperature (>25 °C) had decreased by ~80%. CONCLUSIONS: The integrated system and related operating instructions allow improvement in the quality of sample transportation over time.

Assay performance improved, but which "scorecard" designation for Vitros Troponin I?

BACKGROUND: Since cardiac troponins assay technology should comply with the recommendations of scientific societies (i.e. imprecision (10%) at the 99th percentile value observed in healthy subjects being the analytical qualifying aspect), the aim of the present study was to evaluate whether an improved troponin assay (Vitros Troponin I ES) provides data that meet the "guideline acceptable"criteria recently defined in a proposed scorecard. METHODS: Vitros Troponin I ES, an enhanced chemiluminescence immunoassay, was evaluated in a multicenter study considering: limit of blank (LOB, 60 replicates of 0 calibrators), limit of detection (LOD, 12 measurements for each of 5 serum pools), precision, linearity using control materials and serum plasma pool; matrix samples study matching serum and lithium-heparin plasma (n=107 hospitalized patients); the 99th percentile limit in serum samples from 500 healthy Caucasian donors. RESULTS: LOB and LOD, 0.0029 µg/L and 0.0030 µg/L respectively; coefficients of variation (total CV%), obtained by running 3 levels of control materials and 10 serum pools, from 15.2% (x(-)=0.014 µg/L) to 2.0% (x(-)=5.324 µg/L); method, linear up to 70 µg/L. No significant differences were found between serum and lithium-heparin matched sample (p=0.48) values; 99th percentile limit of cTnI distribution in healthy donors, 0.021 µg/L. CONCLUSION: Since its analytical reliability meets the proposed performance and scorecard requirements, the Vitros TropI method can be considered "contemporary" and "guideline acceptable".

Performance characteristics of laboratory testing and clinical outcomes.

In order to demonstrate the relationship between performance characteristics of laboratory tests and clinical outcomes, diabetes seems to represent a paradigmatic disease: diagnosis, monitoring of therapeutic efficacy and prognosis are adequately achieved by means of laboratory testing. Starting from a simple molecule, glucose, used for the diagnosis of diabetes, continuing with creatinine, used for monitoring renal function in diabetic patients and concluding with cardiac troponins, a recognised gold standard for the diagnosis and risk stratification of cardiovascular diseases, several criticisms may be stressed considering the current methodological state-of-the art. Finally, an often overlooked aspect of performance, the analytical interferences, being responsible of unexpected results, that in turn depend from unknown or undisclosed factors will be discussed, concerning in particular, in our paper, the macroprolactin and the heterophilic antibodies aspects.

Cardiac troponin I at birth is of fetal-neonatal origin.

OBJECTIVE: Neonates produce predominantly skeletal muscle troponin I (TnI) in the myocardium; however, in asphyxiated neonates, high levels of cardiac troponin I (cTnI) have been found. We hypothesised that in these circumstances cTnI could be from the mother or the result of a change in fetal/neonatal production in response to an insult. In this study, we aimed to compare cTnI concentrations in asphyxiated neonates with those of their respective mothers. METHODS: In this prospective observational study, we enrolled all asphyxiated neonates transferred by the Veneto Region Neonatal Transport Service in the period 1 January 2006 to 31 March 2007. Asphyxia was defined as a pH < or =7.00 and/or a base deficit of > or =16 mmol per litre. Neonatal and maternal blood samples were obtained for cTnI determination. RESULTS: We enrolled 19 asphyxiated neonates (median gestational age: 39 weeks, interquartile range 34-40; birth weight 3100 g, 1950-3340). Their cTnI concentrations were significantly higher in comparison with their mothers: 0.24 microg/l (0.13-0.50) vs 0.04 microg/l (0.04-0.04); p<0.01. CONCLUSIONS: Increased cTnI concentrations detected in asphyxiated neonates are of neonatal origin and are not derived from the mother. In asphyxiated neonates, there may be predisposing factors that could cause earlier switching from skeletal TnI to cTnI in the myocardium.

Creatine-kinase MB mass: age and sex-associated reference limits in two different platforms that use the same method.

BACKGROUND: Recent updated NACB guidelines suggest that troponins are the biomarker of choice for the detection of myocardial necrosis, but the CK-MB mass is still considered an effective and alternative indicator when troponin assays are not available. The aim of the present study was to compare the reliability of two different analytical platforms in establishing the gender-specific 99th percentile for the CK-MB mass. METHODS: Serum samples collected from healthy subjects were investigated in two different laboratories, LAB 1 (354 subjects: 222 men, 132 women; median age, 40 years, range 19-64 years) and LAB 2 (330 subjects: 224 men, 106 women; median age, 41 years, range 18-71 years), in order to determine the CK-MB mass (microg/L) using the Access((R)) CKMB method (Beckman Coulter), a two-site immunoenzymatic sandwich assay, on UniCel DxI 800 (LAB 1) and Access((R)) 2 (LAB 2) analyzers (Beckman Coulter). The related plasma samples (lithium-heparin) were also evaluated in LAB 2. RESULTS: Total imprecision (CV%), calculated in control materials, ranged from 6.00 to 9.05 (concentration range, 3.82-36.37) in LAB 1 and from 7.05 to 5.02 in LAB 2 (concentration range, 3.63-34.18). A statistically significant gender-related difference (p<0.05) was found in the whole population studied, values in men being higher than those in women: median=1.86 vs 1.22; 99th percentile=7.64 vs 5.19. The median values in subjects aged 18-28 years (group 1) were lower than those in the other 4 groups (2-5): 1.12 vs 1.59, vs 1.78, vs 1.95 and vs 2.03. The same age-related trend was also observed for CK-MB plasma values, which were comparable to those observed in the matched-serum samples: median 1.12 vs 1.10 (group 1), 1.45 vs 1.50, (group 5). CONCLUSIONS: The two different analytical platforms provide comparable results. The finding that CK-MB mass values are significantly higher in males than in females represents a relevant information, that will impact on patient classification when a myocardial necrosis has been suspected. Actually, however, numerous assays commercially available, lack of this information.

An open population screening study for HFE gene major mutations proves the low prevalence of C282Y mutation in Central Italy.

BACKGROUND: The C282Y mutation in the HFE gene is responsible for most cases of hereditary haemochromatosis. AIM: To investigate the allele frequency of HFE mutations and the associations between mutations and cases of iron overload or liver diseases in an open population of Central Italy. METHODS: A total of 502 individuals over 8 years of age, comprising 203 males and 299 females, who were residents in Arsita (a small town in Central Italy), were assayed for: C282Y, H63D and S65C mutations of the HFE gene by TaqMan probes; body mass index, serum ferritin, transferrin saturation, transaminases, GGT, glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, HBV and HCV serum markers. Information was obtained on alcohol intake. Liver ultrasound was performed in 334 (67%) subjects. RESULTS: The allele frequencies for C282Y, H63D and S65C were 2%, 15%, and 0.01%, respectively. C282Y/wt was found in 19 subjects (4%), H63D/wt in 127 (25%), H63D/H63D in 11 (2%) and S65C/wt in one (2.0 per thousand). No homozygosity for C282Y or compound mutation (C282Y/H63D) was found in the study population, but 27 subjects (5%) had TfSat >45% (including 10 subjects with high serum ferritin). Overall, 49 subjects (9.8%) were HCV-RNA-positive. Logistic regression analysis indicated that male gender (P = 0.000) and hepatic steatosis (P = 0.017) were independent variables correlating to a high serum ferritin. CONCLUSION: C282Y HFE mutation is less frequent in Central Italy than in Northern Italy.

[Acute effects of environmental pollution on the urban vigilants airways]. / Effetto acuto dell'inquinamento ambientale sulle vie aeree in vigili urbani.

AIM OF THE STUDY: The purpose of this study was to evaluate whether the acute exposure to air pollution, in a group of policemen of Padua, is correlated with increased inflammatory biomarkers (exhaled nitric oxide, feNO) and alterations of bronchiolar cells (assessed by CC16 Clara cell-specific protein). METHODS: We studied 44 healthy, non-smokers divided in exposed to traffic and controls (office workers). Before and after the Monday shift serum and urinary concentration of CC16, feNo and spirometry were measured in each subject. Data on air pollutants, PM2.5, PM10, SO2, NO2, CO, O3 were collected from official bulletin online (ARPAV). RESULTS: In exposed policemen serum CC16 decreased after shift (before 4.6 +/- 0.2 vs after 6.4 +/- 0.8 ng/ml, = 0.02), while feNO increased significantly (33.2 +/- 4.4 vs 29.7 +/- 3.9 ppb, p = 0.02). feNO cross-shift changes were positively correlated with environmental SO2 levels (rho = 0.48; p = 0.01). CONCLUSIONS: Our results suggest that in healthy and nonsmokers subjects the exposure to air pollution is associated with subclinical airway inflammation and decrease of bronchiolar epithelium function.

Quality specifications for biochemical markers of myocardial injury.

BACKGROUND: The current approach to the diagnosis and monitoring of myocardial damage, recognizes to biochemical markers, and in particular to troponins, a key role being well demonstrated that all elevated values were associated with a worsened prognosis. In 2001, the IFCC Committee on Standardization of Markers of Cardiac Damage published guidelines addressing the quality specifications for troponin assays in order to guarantee an analytical performance satisfying medical requirements and to standardize the quality of commercial methods. We describe how the application of quality specifications may be useful in daily practice, in order to provide advice to clinicians in the investigations of complex clinical cases of patients suffering from myocardial damage. MATERIALS AND METHODS: The samples from three patients (cases 1-3) admitted to the hospital with symptoms suggestive of cardiac disease, showing high troponin I (cTnI) values not correlated with clinical condition, were investigated in order to verify the accuracy of the laboratory data. The standard of quality specifications related to assay specificity, imprecision and interferences were evaluated using different platforms for cTnI assays, carrying out imprecision profile and specific studies on more common interferents in immunoassays. RESULTS: The obtained results allow us to demonstrate two cases of false-positive cTnI values attributable to a macrocomplex between a modified "in vivo" cTnI and immunoglobulin G (case 1) and to a presence of heterophilic antibodies affecting the RxL Dimension procedure (case 3). Instead, the accuracy of data obtained in case 2 was evidenced by the imprecision profile obtained in our laboratory and by the comparison of results between different laboratories using same platform. CONCLUSIONS: The lack of standardization as well as the wide differences in the development of each assay give rise to major concerns regarding cTnI determinations. The laboratory must therefore check the compliance between the analytical characteristics of the method utilised against recommended quality specifications for a reliable understanding of the frequency of false-positive results as well as other serious analytical errors.

Serum human cartilage glycoprotein 39 as a marker of arthritis associated with inflammatory bowel disease.

BACKGROUND: Common blood markers of arthritis are difficult to interpret in arthritis associated with inflammatory bowel disease (IBD) owing to the coexistence of two inflammatory events. No specific serological disease marker is available for IBD. OBJECTIVE: To determine a value of serum human cartilage glycoprotein 39 (HC gp39) as a marker of arthritis associated with IBD. METHODS: Serum levels of HC gp39 and ultrasensitive C reactive protein (CRP) were determined in 121 patients with IBD: 58 without arthritis (IBD-nonA) and 63 with arthritis (IBD-A), and in 20 healthy controls. IBD was classified as active (aIBD) and non-active (naIBD), and patients with IBD-A were classified as type I, II, and III arthritis by clinical activity indices. RESULTS: HC gp39 was higher in IBD-A than in IBD-nonA (p<0.001) and controls (p<0.01), while no difference was found between IBD-nonA and controls. CRP was increased in both IBD-A and IBD-nonA compared with the controls (p<0.01 and <0.05, respectively) and in aIBD-nonA v naIBD-nonA (p<0.05), but no difference in CRP was found between aIBD-A and naIBD-A. Finally, a correlation was found between the number of affected joints (NAJ) and HC gp39 (r = 0.6, p<0.001). DISCUSSION: Increased serum levels of HC gp39, which were higher in IBD-A than in IBD-nonA, suggest that this substance might be a marker of arthropathy in IBD. HC gp39, because of its relationship with NAJ in IBD-A, may also be proposed as a disease activity marker in arthritis associated with IBD.