Clinical applicability of Quantiferon-TB-Gold testing in psoriasis patients during long-term anti-TNF-alpha treatment: a prospective, observational study

BACKGROUND

Psoriasis patients who are treated with tumour necrosis factor (TNF)-alpha antagonists are at increased risk of reactivation of latent tuberculosis infection (LTBI) and should be adequately screened and monitored during active treatment.

OBJECTIVES

To evaluate in a prospective study, the performance of Quantiferon-TB-Gold in tube (QFT) in vitro assay compared to the conventional tuberculin skin test (TST) in detecting LTBI among a cohort of non-BCG-vaccinated patients with moderate-to-severe psoriasis during long-term treatment (12 months) with TNF-alpha antagonists.

METHODS

A total of 50 patients underwent QFT and TST testing at baseline and after 6 and 12 months of continuous anti-TNF-alpha treatment. Diagnosis of LTBI was made on the basis of a positive QFT result and negative chest-radiographic and microbiological assays. Patients with LTBI were subjected to standard isoniazid chemoprophylaxis and after 1 month, they resumed anti-TNF-alpha treatment with subsequent QFT and TST testing after 6 months. In all the cases, a follow-up period of 12 months was observed.

RESULTS

During the 12-month-study period, 14% of patients presented a QFT conversion. During active anti-TNF-alpha treatment, a QFT conversion was observed in 10% of patients (five cases). Agreement between QFT and TST was moderate (κ=0.408) at screening, good (κ=0.734) after 6 months and fair (κ=0.328) after 12 months of treatment. A total of 18% of patients presented a positive, discordant TST during the study period.

CONCLUSIONS

A single-test QFT-based screening strategy for LTBI in psoriasis patients receiving long-term anti-TNF-alpha treatment could reduce the incidence of false-positive LTBI cases, preventing unnecessary TB chemoprophylaxis.

Growth factor receptors gene expression and Akt phosphorylation in benign human thyroid nodules are unaffected by chronic thyrotropin suppression

Levothyroxine (L-T4)-based suppression of thyrotropin (TSH) secretion is widely used to prevent the growth of benign thyroid nodules, although the effectiveness of this approach has been demonstrated only in a subset of patients. In this study, we analyzed the in vivo effects of L-T4-mediated TSH suppression on elements of insulin/IGF-1-dependent growth-regulating pathways in tissues from patients with benign thyroid nodules. Nodular and non-nodular tissue specimens were collected from 63 patients undergoing thyroidectomy. 32 had received preoperative TSH suppressive therapy with TSH levels consistently below 0.5 mU/l (L-T4 group). TSH suppression had not been used in the other 31, and their TSH levels were normal (0.8-4 mU/l (control group). Quantitative RT-PCR was used to measure mRNA levels for TSH receptor, IGF1, IGF-1 receptor, insulin receptor, insulin receptor substrate 1 in nodular and non-nodular tissues from the 2 groups. Akt and phosphorylated Akt protein levels were detected by Western blot. Mean levels of mRNA for all genes tested were similar in the 2 groups, in both nodular and non-nodular tissues. The 2 groups were also similar in terms of phosphorylated Akt protein levels (measured by densitometric scan in 10 randomly selected nodules from each group). This is the first demonstration based on the study of human thyroid tissues that TSH suppression does not affect the expression of components of the insulin/IGF-1-dependent signaling pathways regulating thyrocyte growth. This may explain the lack of effectiveness of TSH-suppressive therapy in a substantial percentage of benign thyroid nodules.

Surveillance of adenoviruses and noroviruses in European recreational waters

Exposure to human pathogenic viruses in recreational waters has been shown to cause disease outbreaks. In the context of Article 14 of the revised European Bathing Waters Directive 2006/7/EC (rBWD, CEU, 2006) a Europe-wide surveillance study was carried out to determine the frequency of occurrence of two human enteric viruses in recreational waters. Adenoviruses were selected based on their near-universal shedding and environmental survival, and noroviruses (NoV) selected as being the most prevalent gastroenteritis agent worldwide. Concentration of marine and freshwater samples was done by adsorption/elution followed by molecular detection by (RT)-PCR. Out of 1410 samples, 553 (39.2%) were positive for one or more of the target viruses. Adenoviruses, detected in 36.4% of samples, were more prevalent than noroviruses (9.4%), with 3.5% GI and 6.2% GII, some samples being positive for both GI and GII. Of 513 human adenovirus-positive samples, 63 (12.3%) were also norovirus-positive, whereas 69 (7.7%) norovirus-positive samples were adenovirus-negative. More freshwater samples than marine water samples were virus-positive. Out of a small selection of samples tested for adenovirus infectivity, approximately one-quarter were positive. Sixty percent of 132 nested-PCR adenovirus-positive samples analysed by quantitative PCR gave a mean value of over 3000 genome copies per L of water. The simultaneous detection of infectious adenovirus and of adenovirus and NoV by (RT)PCR suggests that the presence of infectious viruses in recreational waters may constitute a public health risk upon exposure. These studies support the case for considering adenoviruses as an indicator of bathing water quality.

A Multicenter Open-Label Experience on the Response of Psoriasis to Adalimumab and Effect of Dose Escalation in Non-Responders: The Aphrodite Project

There is much evidence to show the efficacy of adalimumab, a human monoclonal antibody targeting tumour necrosis factor-alpha, in the treatment of plaque psoriasis. In this open-label experience, 147 high-need patients suffering from plaque psoriasis, with a mean Psoriasis Area and Severity Index (PASI) of 18.8, and concomitant psoriatic arthritis (PsA) received subcutaneous injections of 40 mg of adalimumab every other week (EOW). This was actually the dosage regimen recommended for PsA, as the drug had not then been approved for psoriasis at the time of the patients' enrolment. At week 12, an improvement of at least 50% of the PASI (PASI-50) was observed in 111 (77%) patients. Continuation of treatment in responders with adalimumab 40 mg EOW led to a sustained response, with the PASI-50 achieved by 97% of patients in the as-treated analysis at week 24 (PASI-75 in 82% and PASI-90 in 45% out of 109 patients who received EOW injections up to week 24). Thirty subjects who failed to attain the PASI-50 response at week 12 were treated with adalimumab 40 mg every week for a further 12 weeks. At week 24, 80% of these patients obtained a PASI-50 response after dose escalation. Tolerability was good in the majority of patients. Only two patients discontinued treatment because of an adverse event (repeated flu-like episodes and a pleuropericarditis of unknown origin, respectively).

Growth inhibition of medullary thyroid carcinoma cells by pyrazolo-pyrimidine derivates

There is no effective treatment for recurrent or metastatic medullary thyroid carcinoma (MTC), a tumor arising from thyroid C-cells commonly presenting an inherited or acquired RET mutation. In this study we examined the sensitivity of two human MTC cell lines to novel pyrazolopyrimidine derivates, able to inhibit src-family tyrosine kinase activity. In TT cells [carrying the multiple endocrine neoplasia (MEN)2A Ret mutation Cys 634Trp] and MZ-CRC-1 cells (carrying the MEN2B RET mutation Met891Thr), one of these compounds, namely Si 34, determined a significant growth inhibitory effect (approximately 90% vs control for TT, 80% vs control for MZ-CRC-1) mainly due to enhanced cell mortality after a 6-day incubation. At concentrations that increased cell mortality, neither biochemical or morphological characteristics of apoptosis were detected in TT and MZCRC- 1 cells treated with Si 34. These results, when confirmed in other in vivo preclinical models, suggest that this novel tyrosine kinase inhibitor may be useful for the treatment of MTC.

An ultracentrifugation-based approach to the detection of hepatitis A virus in soft fruits

A method was developed for detection of hepatitis A virus (HAV) in soft fruits (raspberries and strawberries). After washing the sample in 1 M sodium bicarbonate with added soya protein, fruits were removed by slow speed centrifugation, then particulate material and residual pectin were removed from the supernatant by flocculation and pectinase treatment during another slow speed centrifugation. Virus particles were then sedimented by ultracentrifugation. RNA was extracted from the virus particles, and nested RTPCR was performed on the nucleic acid extract. Nested RTPCR comprised an RTPCR, followed by PCR to amplify sequences within the amplicon. Internal amplification controls (IACs) were constructed for both the RTPCR and the PCR. The sensitivity of the nested RTPCR was approximately 10 RTPCRU. The overall method was shown to be able to detect 10(4) RTPCRU HAV in 90 g fresh strawberries, and 10(3) RTPCRU HAV in 60 g fresh raspberries. It is estimated that the lowest possible limit of detection of the method should be between 40 and 400 RTPCRU HAV per fruit sample. The method can be performed within one day, in suitably equipped microbiological laboratories, and is suitable for routine screening of food samples, and for analysis of suspected samples, e.g. during outbreak investigations.

A centrifugation-based method for extraction of norovirus from raspberries

A method was developed for extraction of noroviruses from raspberries. The method consists of removal of virus from fruit surfaces by alkaline extraction, then removal of residual food debris by centrifugation, followed by concentration of virus particles by ultracentrifugation. The efficiency of the extraction was estimated by comparison of reverse transcription PCR signals obtained from fruit extracts and the norovirus suspension that was used to contaminate the fruit. Noroviruses were recovered with at least 10% efficiency from 60-g raspberry samples (n = 10). The sample treatment reported here should be applicable for harnessing to any norovirus reverse transcription PCR and form the basis of a dependable method to detect noroviruses in raspberries.

Real-time PCR-based methods for detection of Mycobacterium avium subsp. paratuberculosis in water and milk

A real-time PCR assay for quantitative detection of Mycobacterium avium paratuberculosis has been developed. It targets and amplifies sequences from the IS900 insertion element which is specific for this bacterium, and includes an internal amplification control. The assay was tested against 18 isolates of M. avium paratuberculosis, 17 other mycobacterial strains, and 25 non-mycobacterial strains, and was fully selective. It is capable of detecting <3 genomic DNA copies with 99% probability or alternatively, using cells directly in the reaction, 12 cells can be detected with 99% probability. Using prior centrifugation, the assay was able to consistently and quantifiably detect 10(2) M. avium paratuberculosis cells in 20 ml artificially contaminated drinking water. With a simple detergent and enzymatic sample pretreatment before centrifugation and nucleic acid extraction, the assay was able to consistently detect 10(2) M. avium paratuberculosis in 20 ml artificially contaminated semi-skimmed milk. The assay will be a useful addition to the range of diagnostic tools available for the study of M. avium paratuberculosis.

A molecular beacon-based real-time NASBA assay for detection of Mycobacterium avium subsp. paratuberculosis in water and milk

A molecular beacon-based real-time NASBA assay for detection and identification of Mycobacterium avium subsp. paratuberculosis has been developed. It targets and amplifies sequences from the dnaA gene which are specific for this bacterium. The assay includes an internal amplification control, to allow identification of inhibited reactions. The assay was tested against 18 isolates of M. avium subsp. paratuberculosis, 17 other mycobacterial strains and 25 non-mycobacterial strains, and was fully selective in that it detected all the targets but none of the non-targets. The lowest number of cells which the assay can detect with 99% probability is 150-200 cells per reaction (as determined using pure culture suspensions). Using centrifugation and nucleic acid extraction as sample treatment, the assay was able to consistently detect 10(3) M. avium subsp. paratuberculosis cells in 20 ml artificially contaminated drinking water. With a simple detergent and enzymatic sample pretreatment before centrifugation and nucleic acid extraction, the assay was able to consistently detect 10(4) M. avium subsp. paratuberculosis cells in 20 ml artificially contaminated semi-skimmed milk. The assay will be a useful addition to the range of diagnostic tools available for the study of M. avium subsp. paratuberculosis.

Construction strategy for an internal amplification control for real-time diagnostic assays using nucleic Acid sequence-based amplification: development and clinical application

An important analytical control in molecular amplification-based methods is an internal amplification control (IAC), which should be included in each reaction mixture. An IAC is a nontarget nucleic acid sequence which is coamplified simultaneously with the target sequence. With negative results for the target nucleic acid, the absence of an IAC signal indicates that amplification has failed. A general strategy for the construction of an IAC for inclusion in molecular beacon-based real-time nucleic acid sequence-based amplification (NASBA) assays is presented. Construction proceeds in two phases. In the first phase, a double-stranded DNA molecule that contains nontarget sequences flanked by target sequences complementary to the NASBA primers is produced. At the 5' end of this DNA molecule is a T7 RNA polymerase binding sequence. In the second phase of construction, RNA transcripts are produced from the DNA by T7 RNA polymerase. This RNA is the IAC; it is amplified by the target NASBA primers and is detected by a molecular beacon probe complementary to the internal nontarget sequences. As a practical example, an IAC for use in an assay for the detection of Mycobacterium avium subsp. paratuberculosis is described, its incorporation and optimization within the assay are detailed, and its application to spiked and natural clinical samples is shown to illustrate the correct interpretation of the diagnostic results.

Validation of a PCR-based method for detection of food-borne thermotolerant campylobacters in a multicenter collaborative trial

A PCR-based method for rapid detection of food-borne thermotolerant campylobacters was evaluated through a collaborative trial with 12 laboratories testing spiked carcass rinse samples. The method showed an interlaboratory diagnostic sensitivity of 96.7% and a diagnostic specificity of 100% for chicken samples, while these values were 94.2 and 83.3%, respectively, for pig samples.

A validated PCR-based method to detect Listeria monocytogenes using raw milk as a food model--towards an international standard

A PCR assay with an internal amplification control was developed for Listeria monocytogenes. The assay has a 99% detection probability of seven cells per reaction. When tested against 38 L. monocytogenes strains and 52 nontarget strains, the PCR assay was 100% inclusive (positive signal from target) and 100% exclusive (no positive signal from nontarget). The assay was then evaluated in a collaborative trial involving 12 European laboratories, where it was tested against an additional 14 target and 14 nontarget strains. In that trial, the inclusivity was 100% and the exclusivity was 99.4%, and both the accordance (repeatability) and the concordance (reproducibility) were 99.4%. The assay was incorporated within a method for the detection of L. monocytogenes in raw milk, which involves 24 h of enrichment in half-Fraser broth followed by 16 h of enrichment in a medium that can be added directly into the PCR. The performance characteristics of the PCR-based method were evaluated in a collaborative trial involving 13 European laboratories. In that trial, a specificity value (percentage of correct identification of blank samples) of 81.8% was obtained; the accordance was 87.9%, and the concordance was 68.1%. The sensitivity (correct identification of milk samples inoculated with 20 to 200 L. monocytogenes cells per 25 ml) was 89.4%, the accordance was 81.2%, and the concordance was 80.7%. This method provides a basis for the application of routine PCR-based analysis to dairy products and other foodstuffs and should be appropriate for international standardization.

Multicenter validation of PCR-based method for detection of Salmonella in chicken and pig samples

As part of a standardization project, an interlaboratory trial including 15 laboratories from 13 European countries was conducted to evaluate the performance of a noproprietary polymerase chain reaction (PCR)-based method for the detection of Salmonella on artificially contaminated chicken rinse and pig swab samples. The 3 levels were 1-10, 10-100, and 100-1000 colony-forming units (CFU)/100 mL. Sample preparations, including inoculation and pre-enrichment in buffered peptone water (BPW), were performed centrally in a German laboratory; the pre-PCR sample preparation (by a resin-based method) and PCR assay (gel electrophoresis detection) were performed by the receiving laboratories. Aliquots of BPW enrichment cultures were sent to the participants, who analyzed them using a thermal lysis procedure followed by a validated Salmonella-specific PCR assay. The results were reported as negative or positive. Outlier results caused, for example, by gross departures from the experimental protocol, were omitted from the analysis. For both the chicken rinse and the pig swab samples, the diagnostic sensitivity was 100%, with 100% accordance (repeatability) and concordance (reproducibility). The diagnostic specificity was 80.1% (with 85.7% accordance and 67.5% concordance) for chicken rinse, and 91.7% (with 100% accordance and 83.3% concordance) for pig swab. Thus, the interlaboratory variation due to personnel, reagents, thermal cyclers, etc., did not affect the performance of the method, which will be proposed as part of a developing international PCR standard.

Toward an international standard for PCR-based detection of foodborne Escherichia coli O157: validation of the PCR-based method in a multicenter interlaboratory trial

The performance of a polymerase chain reaction (PCR) method for detection of Escherichia coli O157, previously validated on DNA extracted from pure cultures, was evaluated on spiked cattle swabs through an interlaboratory trial, including 12 participating laboratories from 11 European countries. Twelve cattle swab samples, spiked at 4 levels (0, 1-10, 10-100, and 100-1000 colony-forming units, in triplicate) with E. coli O157 were prepared centrally in the originating laboratory; the receiving laboratories performed pre-PCR treatment followed by PCR. The results were reported as positive when the correct amplicons were present after gel electrophoresis. The statistical analysis, performed on 10 sets of reported results, determined the diagnostic sensitivity to be 92.2%. The diagnostic specificity was 100%. The accordance (repeatability) was 90.0%, calculated from all positive inoculation levels. The concordance (reproducibility) was 85.0%, calculated from all positive inoculation levels. The concordance odds ratio (degree of interlaboratory variation calculated from all positive inoculation levels) was 1.58, indicating the robustness of the PCR method. Thus, the interlaboratory variation due to personnel, reagents, minor temperature or pH fluctuations and, not least, thermal cyclers, did not affect the performance of the method, which is currently being considered as part of an intenational PCR standard.

Coenzyme Q, Vitamin E and Apo-E alleles in Alzheimer Disease

Neurodegenerative Diseases represent the most common cause of Dementia, about 5-10% of the population aged above 65 years and about 30% above 80 years. A study about Apo-E alleles, Coenzyme Q and Vitamins E as biological indicators was performed in plasma samples of patients aged from 30 to 85 years, affected by Neurodegenerative Diseases. The results were compared with control subjects of approximately the same ages as the reference group. A frequency of 21.7% of epsilon4 allele in control group was estimated, against 15.8% observed in patients. The frequency of epsilon2 and epsilon3 alleles was 13.0% and 65.2% in the control group against 10.5% and 73.7% in patients. No significant differences were observed between the frequency of epsilon3/epsilon3 genotype and epsilon3/epsilon4 genotype in the control group compared to patients' group. The frequencies observed in epsilon2/epsilon3 genotype groups were 8.7% vs 15.8% and of e2/e4 genotype 17.4% vs 5.3%. The epsilon2/epsilon2 and epsilon4/epsilon4 genotypes were not identified in any groups. Plasma CoQ10 concentrations were similar in patient and control groups and no differences were found even taking into account the distribution of male and female subjects in the two groups. Also, vitamin E did not provide evidence of any differences between groups and the analysis among sexes revealed that again vitamin E concentrations were similar in between subgroups.

Nuclear detecting systems at LNL and LNS: foreseen experiments to provide basic data for heavy-ion risk assessment

The use of existing detecting systems developed for nuclear physics studies allows collecting data on particle and ion production cross-sections in reactions induced by Oxygen and Carbon beams, of interest for hadrontherapy and heavy-ion risk assessment. The MULTICS and GARFIELD apparatus, together with the foreseen experiments, are reviewed.

Strong enhancement of extremely energetic proton production in central heavy ion collisions at intermediate energy

The energetic proton emission has been investigated as a function of the reaction centrality for the system (58)Ni + (58)Ni at 30A MeV. Extremely energetic protons (E(NN)(p) > or = 130 MeV) were measured and their multiplicity is found to increase almost quadratically with the number of participant nucleons, thus indicating the onset of a mechanism beyond one- and two-body dynamics.

Gene-diet interactions and plasma lipoproteins: role of apolipoprotein E and habitual saturated fat intake

To test whether plasma lipoprotein levels and low density lipoprotein (LDL) particle size are modulated by an interaction between habitual saturated fat intake and apolipoprotein E (APOE) genotype, we studied 420 randomly selected free-living Costa Ricans. The APOE allele frequencies were 0.03 for APOE2, 0.91 for APOE3, and 0.06 for APOE4. The median saturated fat intake, 11% of energy, was used to divide the population into two groups, LOW-SAT (mean intake 8.6% energy) represents those below median intake, and HIGH-SAT (mean intake 13.5%) represents those above median intake. Significant interactions between APOE genotype and diet were found for VLDL (P = 0.03) and HDL cholesterol (P = 0.02). Higher saturated fat intake was associated with higher VLDL cholesterol (+29%) and lower HDL cholesterol (-22%) in APOE2 carriers, while the opposite association was observed in APOE4 carriers (-31% for VLDL cholesterol and +10% for HDL cholesterol). Higher saturated fat intake was associated with smaller LDL particles (-2%, P < 0.05) in APOE2 carriers, and larger LDL particles (+2%, P < 0.05) in APOE4 carriers, but the gene-diet interaction was not statistically significant (P = 0.09). Higher saturated fat intake was associated with higher LDL cholesterol in all genotypes (mean +/- SEM, LOW-SAT 2.61 +/- 0.05 vs. HIGH-SAT 2.84 +/- 0.05 mmol/L, P = 0.009). These data suggest that the APOE2 allele could modulate the effect of habitual saturated fat on VLDL cholesterol and HDL cholesterol in a population with an average habitual total fat intake of less than 30%.

Predictions of growth for Listeria monocytogenes and Salmonella during fluctuating temperature

We studied the predictive performance of a dynamic modelling approach, combined with predictions from the Food MicroModel software, applied to the growth of Listeria monocytogenes and Salmonella in pasteurised milk, chicken liver pâté and minced chicken, under constant as well as fluctuating temperatures. We found that, in general, the accuracy of a prediction under fluctuation temperature was similar to that under constant temperature. Generally, there was a good agreement between predictions and observations. However, the growth of Listeria monocytogenes in pasteurised milk was inhibited largely by the natural flora present.

Flavonoid glycosides of Barbarea vulgaris L. (Brassicaceae)

Seven flavonoid derivatives were for the first time isolated from aerial parts of an alimentary and medicinal plant of the Brassicaceae family, Barbarea vulgaris L. The products were characterized on the basis of spectroscopic NMR ((1)H, (13)C, COSY, HMQC, HMBC) and FAB-MS data. The occurrence of flavonoids in this plant is interesting for their important nutritional properties and for chemotaxonomical pourposes.