Publications (13)30.29 Total impact
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Article: Interferon-gamma release assays in the detection of latent tuberculosis infection in patients with inflammatory arthritis scheduled for anti-tumour necrosis factor treatment.
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ABSTRACT: Biological agents, particularly anti-Tumour Necrosis Factor (TNF)-α agents, have emerged as an effective treatment in patients with chronic inflammatory diseases. An association between anti-TNF-α antibodies and reactivation of latent tuberculosis infection (LTBI) has been established. Appropriate screening for TB infection has become mandatory before starting a treatment based on TNF-α inhibition. The objective was to determine the usefulness of IFN-γ release assays in diagnosing LTBI in patients with inflammatory rheumatic diseases scheduled for anti-TNF-α treatment. The study included 53 individuals with inflammatory rheumatism. All patients had a TST, a chest radiograph, QuantiFERON Gold In-Tube (QFN-G-IT) and T-SPOT.TB. To investigate the influence of non-tuberculous mycobacteria (NTM) infections on non-BCG-vaccinated patients, with a positive TST result and both negative IFN-γ assays, we performed an ex vivo ELISPOT, stimulating the cells separately with NTM sensitins. TST was positive in 7 cases, T-SPOT.TB in 11 and QFN-G-IT in 9 cases. Agreement between TST and T-SPOT.TB and QFN-G-IT was 77.35% (κ = 0.33 and κ = 0.40, respectively), and between both in vitro tests, it was 83.01% (κ = 0.57). Of the three patients with positive TST and negative T-SPOT.TB and QFN-G-IT, one positive ELISPOT result was obtained after stimulation with NTM sensitins. Positive TST, T-SPOT.TB and QFN-G-IT results were not affected by the immunosuppressive therapies. IFN-γ release assays are useful methods for avoiding TST false-positive results, but in those patients with a high risk of developing active TB and in the absence of predictive value studies in this specific kind of population for knowing how safe is the use of IGRAs alone, the combined use of TST and IFN-γ tests should be recommended in order to increase the overall number of LTBI diagnoses.Clinical Rheumatology 01/2012; 31(5):785-94. · 2.00 Impact Factor -
Article: Specific Mycobacterium tuberculosis T cell responses to RD1-selected peptides for the monitoring of anti-tuberculosis therapy.
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ABSTRACT: Recently, a selection of HLA class II-restricted epitopes of ESAT-6 and CFP-10 Mycobacterium tuberculosis proteins from the region of difference (RD) 1 have been described. We have evaluated the host interferon-gamma (IFN-γ) T cell response to these RD1 selected peptides at the beginning and during anti-tuberculosis therapy. We studied 29 pulmonary TB patients enrolled at the beginning of treatment and 24 enrolled during treatment. We performed T-SPOT.TB and ELISPOT with RD1 selected peptides. Patients included at the beginning of treatment responded producing IFN-γ after antigen stimulation in 89.7% by means of T-SPOT.TB and 79.3% by means of RD1 selected ELISPOT. In contrast, for patients included during treatment the percentages were 87.5% and 25%, respectively. Differences in sensitivities between patients evaluated at the beginning and during treatment were only significant for RD1 selected ELISPOT (p < 0.0001). The host immune response to RD1 selected peptides is lower than to T-SPOT.TB during therapy. Immunological assays based on RD1 selected peptides may be useful tools for studying the immune response during anti-tuberculosis therapy.Scandinavian Journal of Infectious Diseases 09/2011; 44(3):161-7. · 1.72 Impact Factor -
Article: Value of procalcitonin, C-reactive protein, and neopterin in exacerbations of chronic obstructive pulmonary disease.
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ABSTRACT: The identification of biological markers in order to assess different aspects of COPD is an area of growing interest. The objective of this study was to investigate whether levels of procalcitonin (PCT), C-reactive protein (CRP), and neopterin in COPD patients could be useful in identifying the etiological origin of the exacerbation and assessing its prognosis. We included 318 consecutive COPD patients: 46 in a stable phase, 217 undergoing an exacerbation, and 55 with pneumonia. A serum sample was collected from each patient at the time of being included in the study. A second sample was also collected 1 month later from 23 patients in the exacerbation group. We compared the characteristics, biomarker levels, microbiological findings, and prognosis in each patient group. PCT and CRP were measured using an immunofluorescence assay. Neopterin levels were measured using a competitive immunoassay. PCT and CRP showed significant differences among the three patient groups, being higher in patients with pneumonia, followed by patients with exacerbation (P < 0.0001). For the 23 patients with paired samples, PCT and CRP levels decreased 1 month after the exacerbation episode, while neopterin increased. Neopterin showed significantly lower levels in exacerbations with isolation of pathogenic bacteria, but no differences were found for PCT and CRP. No significant differences were found when comparing biomarker levels according to the Gram result: PCT (P = 0.191), CRP (P = 0.080), and neopterin (P = 0.109). However, median values of PCT and CRP were high for Streptococcus pneumoniae, Staphylococcus aureus, and enterobacteria. All biomarkers were higher in patients who died within 1 month after the sample collection than in patients who died later on. According to our results, biomarker levels vary depending on the clinical status. However, the identification of the etiology of infectious exacerbation by means of circulating biomarkers is encouraging, but its main disadvantage is the absence of a microbiological gold standard, to definitively demonstrate their value. High biomarker levels during an exacerbation episode correlate with the short-term prognosis, and therefore their measurement can be useful for COPD management.International Journal of COPD 01/2011; 6:157-69. -
Article: Usefulness of two new methods for diagnosing metapneumovirus infections in children.
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ABSTRACT: Human metapneumovirus (hMPV) is associated with acute respiratory tract infections, mainly in paediatric patients. The aim of this study was to evaluate the usefulness of two new commercial techniques available for the detection of hMPV in clinical samples from children: an enzyme immunoassay, hMPV EIA (Biotrin International Ltd), and a molecular assay, real-time RT-PCR (Pro hMPV Real Time Assay Kit; Prodesse). A total of 184 nasopharyngeal aspirate specimens from 173 children aged less than 5 years who were hospitalized with acute wheezing were analysed. Respiratory syncytial virus was detected in 27% of the samples, followed by influenza A virus (6%), parainfluenza virus (PIV)3 (2.2%), adenovirus (2%), PIV1 (1.1%), PIV2 (1.1%), and influenza B virus (0.5%). The presence of hMPV was tested in all samples, using the real-time RT-PCR and EIA. Real-time RT-PCR detected 13 hMPV-positive samples (8%), and EIA detected 17 (9.3%). When the EIA results were compared with those of real-time RT-PCR for the detection of hMPV, a good correlation was found (94%). A relatively low co-infection rate (15%) was observed in our patients. RT-PCR and EIA provide robust methods for the diagnosis of hMPV infection in children.Clinical Microbiology and Infection 02/2010; 16(11):1663-8. · 4.54 Impact Factor -
Article: IFN-γ response on T-cell based assays in HIV-infected patients for detection of tuberculosis infection.
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ABSTRACT: Individuals infected with human immunodeficiency virus (HIV) have an increased risk of progression to active tuberculosis following Mycobacterium tuberculosis infection. The objective of the study was to determine IFN-γ responses for the detection of latent tuberculosis infection (LTBI) with QuantiFERON-TB GOLD In Tube (QFT-G-IT) and T-SPOT.TB in HIV patients, and evaluate the influence of CD4 cell count on tests performance. We studied 75 HIV patients enrolled for ongoing studies of LTBI with T-SPOT.TB, QFN-G-IT and TST. Mean CD4 cell counts ± standard deviation was 461.29 ± 307.49 cells/μl. Eight patients had a BCG scar. T-SPOT.TB, QFN-G-IT and TST were positive in 7 (9.3%), 5 (6.7%) and 9 (12%) cases, respectively. Global agreement between QFN-G-IT and T-SPOT.TB was 89% (κ = 0.275). The overall agreement of T-SPOT.TB and QFN-G-IT with TST was 80.8% (κ = 0.019) and 89% (κ = 0.373), respectively. We have found negative IFN-γ assays results among 2 BCG-vaccinated HIV-infected individuals with a positive TST. In non BCG-vaccinated patients, QFN-G-IT and TST were positive in 5 cases (7.5%) and T-SPOT.TB in 7 (10.4%). In contrast, in BCG-vaccinated patients, only TST was positive in 4/8 (50%) of the cases. The differences obtained in the number of positive results between TST and both IFN-γ assays in BCG vaccinated patients were significant (95% CI 3-97%, p = 0.046), however, the confidence interval is very wide given the small number of patients. In patients with CD4< 200, we obtained only one (5%) positive result with T-SPOT.TB; however, QFN-G-IT and TST were negative in all cases. On the contrary, percentages of positive results in patients with CD4> 200 were 10.9% (6/55), 9.1% (5/55) and 16.4% (9/55) with T-SPOT.TB, QFN-G-IT and TST, respectively. IFN-γ tests have the benefit over TST that are less influenced by BCG vaccination, consequently they are more specific than TST. Although our number of patients with advance immunosuppression is limited, our study suggests that IFN-γ assays are influenced with level of immunosuppression. The use of IFN-γ assays could be a helpful method for diagnosing LTBI in HIV population.BMC Infectious Diseases 01/2010; 10:348. · 3.12 Impact Factor -
Article: Quantitative evaluation of T-cell response after specific antigen stimulation in active and latent tuberculosis infection in adults and children.
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ABSTRACT: We have evaluated the quantitative T-cell response after specific Mycobacterium tuberculosis antigen stimulation in active tuberculosis (TB) and latent TB infection (LTBI) patients. In adults, the median number of T cells after RD1 antigen stimulation was significantly higher in active TB patients than in LTBI patients. In children, the number of responder T cells against the specific antigens was higher in active TB than in LTBI patients, although the differences were not significant. In summary, in patients with suspected clinical TB, although there is overlapping in the number of responder T cells between both groups, a T-cell count above the described threshold could suggest active TB, especially in patients with a high probability of having active TB and low probability of having LTBI. In addition, the results are consistent with the current evidence that T-cell response may indicate mycobacterial burden and disease activity.Diagnostic microbiology and infectious disease 11/2009; 65(3):236-46. · 2.45 Impact Factor -
Article: IFN-gamma-release assays to diagnose TB infection in the immunocompromised individual.
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ABSTRACT: The tuberculin skin test (TST) is used for diagnosing latent TB infection (LTBI). The main limitation of TST is its low sensitivity in populations with the highest risk of progression to active TB: immunosuppressed patients and young children. New IFN-gamma-based tests appear as an alternative to the TST. IFN-gamma-based tests seem more specific than the TST, being closely associated with LTBI factors, and not being affected by bacillus Calmette-Guérin vaccination. Indeterminate results are mainly related to immunosuppression. Looking at the available data, it seems prudent to recommend the utilization of IFN-gamma-based tests after a negative TST result, in order to increase the sensitivity of detecting LTBI cases in severely immunosuppressed patients. In summary, IFN-gamma-based tests appear to be a valuable tool, in combination with the TST, for diagnosing TB infection in immunosuppressed patients.Expert Review of Respiratory Medicine 06/2009; 3(3):309-27. -
Article: Evaluation of a latex agglutination test (PYLOGEN) for the detection of Helicobacter pylori in stool specimens.
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ABSTRACT: The aim of the study was to assess a new latex agglutination (LA) stool antigen assay (PYLOGEN; CerTest Biotec, Zaragoza, Spain) in the diagnosis of Helicobacter pylori infection and to monitor its eradication after treatment. The LA test has been approved for sale in Europe, and its approval from the US Food and Drug Administration is still pending. The individuals enrolled were classified into 3 groups of patients: Group 1 consisted of 38 patients who are H. pylori positive. The diagnosis of H. pylori infection was established if there was concordance between 2 test results (urea breath test [UBT], rapid urease test, and histopathologic study) or if the culture alone was positive. Patients with only 1 positive test were considered indeterminate and were excluded from the study. Group 2 comprised 9 patients without positive tests and who were considered to be H. pylori negative. Group 3 consisted of 57 patients who received eradication treatment. The sensitivity and specificity of the test were 78.9% and 100%, respectively. The results of the UBT of the patients were studied 6 weeks after eradication therapy. The sensitivity and specificity of the LA test relative to UBT for patients after treatment were 75% and 93.3%, respectively.Diagnostic microbiology and infectious disease 03/2009; 63(4):349-53. · 2.45 Impact Factor -
Article: Evaluation of interferon-gamma release assays in the diagnosis of recent tuberculosis infection in health care workers.
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ABSTRACT: Health care workers (HCWs) are a group at risk of latent tuberculosis infection (LTBI). The aims of this study were to determine IFN-gamma response by QuantiFERON-TB GOLD In Tube (QFN-G-IT) and T-SPOT.TB in HCWs, comparing the results with tuberculin skin test (TST); and to analyze the capacity of IFN-gamma tests to detect recent versus remote LTBI with a prolonged stimulation test (PST). A total of 147 HCWs were enrolled; 23 of whom were BCG vaccinated. 95 HCWs (64.6%) had a previous positive TST and were not retested; and 52 HCWs had a previous negative TST or were tested for the first time. When we analysed individuals without previous positive TST, the number of positive results for T-SPOT.TB was 12/52 (23.1%); and for QFN-G-IT, 9/52 (17.3%). The global concordance (kappa) between T-SPOT.TB and QFN-G-IT with TST was 0.754 and 0.929 respectively. Of individuals with previous positive TST, T-SPOT.TB and QFN-G-IT were negative in 51.6% (49/95) and 62.1% (59/95) respectively, decreasing the concordance to 0.321 and 0.288, respectively. In non-BCG vaccinated HCWs with previous positive TST a positive IFN-gamma test was associated with degree of exposure and diameter of TST. PST was performed in 24 HCW with previous positive TST and negative IFN-gamma tests. PST was developed in 3 cell cultures stimulated with medium alone, ESAT-6 and CFP-10, respectively. In the third and sixth day of incubation period, part of the supernatants were replaced with complete medium supplemented with (rIL)-2. On day 9, ELISPOT assay was performed. In 14 samples PST was not valid due to not having enough cells. In 8 cases, the response was negative, and in 2 cases positive, suggesting that these patients were infected with Mycobacterium tuberculosis in some point in the past. Both IFN-gamma tests showed a similar number of positive results, and concordance between the tests was excellent. None of the tests was affected by prior BCG vaccination. IFN-gamma tests are a useful tool for detecting recent infection in HCW population.PLoS ONE 02/2009; 4(8):e6686. · 4.09 Impact Factor -
Article: T-cell responses to the Mycobacterium tuberculosis-specific antigens in active tuberculosis patients at the beginning, during, and after antituberculosis treatment.
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ABSTRACT: The objectives of the study were to assess the performance of the QuantiFERON-TB Gold In-Tube (QFN-G-IT) and the T-SPOT.TB tests in the immunodiagnosis of active tuberculosis (TB) in adult patients, and to study the T-cell interferon gamma (IFN-gamma) responses during treatment and in patients who have recovered after curative treatment and self-healed TB patients. When only analyzing patients included at the beginning of treatment, the sensitivity was 83.3% for T-SPOT.TB and 69.4% for QFN-G-IT. In contrast, when evaluating patients during treatment, the sensitivity of the T-SPOT.TB and QFN-G-IT decreased to 69.8% and 48.8%, respectively. The response to the specific antigens increased after finishing the treatment compared with the values during the treatment. The T-SPOT.TB was more sensitive in diagnosing active TB than the QFN-G-IT. The IFN-gamma tests could be used as a complementary method in the diagnosis of active TB.Diagnostic microbiology and infectious disease 12/2008; 63(1):43-51. · 2.45 Impact Factor -
Article: Role of the T-cell interferon-gamma release assays in preventing reactivation of latent tuberculosis infection in immunosuppressed patients in treatment with anti-TNF agents.
Journal of Crohn s and Colitis 09/2008; 2(3):250-4. · 2.57 Impact Factor -
Article: Comparison of stool antigen immunoassay methods for detecting Helicobacter pylori infection before and after eradication treatment.
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ABSTRACT: The aim of the study was to compare 6 stool antigen immunoassays for detecting Helicobacter pylori before and after eradication treatment. We compared 3 enzyme immunoassay (EIA) and 3 monoclonal immunochromatographic assays in diagnosing infection and in determining H. pylori status after eradication treatment. We evaluated stool samples from 80 patients diagnosed with H. pylori infection and from 18 patients without infection. To confirm H. pylori eradication, we evaluated 40 patients who received H. pylori treatment. The sensitivity and specificity were 87.3% and 83.3% for Immundiagnostik ELISA, 92.5% and 72.2% for HpSA EIA test, 95% and 66.6% for HpStAR EIA, 83.8% and 66.6% for H. pylori Letitest, 52.5% and 94.4% for ImmunoCard HpSA, and 78.8% and 55.5% for RAPID HpStAR, respectively. From the 40 patients evaluated 6 weeks after eradication therapy, the best agreement between the urea breath tests and immunoassay tests was with HpStAR EIA (90%) and H. pylori Letitest (85%). HpStAR EIA and H. pylori Letitest could be used as a routine diagnostic tool in the microbiology laboratory for assessing clinical significance and eradication control of H. pylori infection.Diagnostic Microbiology and Infectious Disease 07/2008; 61(2):150-5. · 2.53 Impact Factor -
Article: Comparison of two commercially available gamma interferon blood tests for immunodiagnosis of tuberculosis.
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ABSTRACT: We evaluated the T-SPOT.TB and Quantiferon-TB Gold In tube (QFN-G-IT) tests for diagnosing Mycobacterium tuberculosis infection. T-SPOT.TB was more sensitive than QFN-G-IT in diagnosing both active and latent infection. Both gamma interferon tests were unaffected by prior Mycobacterium bovis BCG vaccination. Among children who were not BCG vaccinated but had a positive tuberculin skin test, QFN-G-IT was negative in 53.3% of cases, and T-SPOT.TB was negative in 50% of cases.Clinical and vaccine immunology: CVI 02/2008; 15(1):168-71. · 2.37 Impact Factor
Top Journals
Institutions
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2008–2012
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Hospital Universitari Germans Trias i Pujol
Badalona, Catalonia, Spain -
Autonomous University of Barcelona
Cerdanyola del Vallès, Catalonia, Spain
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2011
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University of Barcelona
- Departament de Microbiologia
Barcelona, Catalonia, Spain
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2009–2011
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Instituto de Salud Carlos III
Madrid, Madrid, Spain
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2008–2009
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Fundació Institut Investigació Germans Trias i Pujol
Badalona, Catalonia, Spain
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