Biomedical subjects

T H M Ottenhoff

Publications and source records attributed to T H M Ottenhoff.

11 recordsLinked to original sources

PubMed2007

Effect of tuberculin skin testing on a Mycobacterium tuberculosis-specific interferon-gamma assay.

Recently, interferon-gamma release assays (IGRA) for specific diagnosis of Mycobacterium tuberculosis infection have become available. In recent UK tuberculosis (TB) guidelines, it has been advised to screen for latent M. tuberculosis infection using the tuberculin skin test (TST), followed by IGRA if the TST is positive. Since TST can boost immune responses to tuberculin, the present authors evaluated whether TST administration affects the result of QuantiFERON-TB Gold in-tube (QFT-GIT), a whole blood-based IGRA. QFT-GIT was performed on the day of TST administration and the day of reading in 15 TST-negative subjects, 46 TST-positive subjects with recent or remote exposure to M. tuberculosis and five cured TB patients. No systematic boosting of QFT-GIT responses from negative to positive was observed. Only in a few TST-positive persons did TST enhance pre-existing QFT-GIT responses. Screening for latent Mycobacterium tuberculosis infection using tuberculin skin testing followed by interferon-gamma release assays on the day of reading is a reliable approach, as the specificity of QuantiFERON-TB Gold in-tube is not affected by prior tuberculin skin test administration.

Adult↗

PubMed2006

Evaluation of recombinant serine-rich 45-kDa antigen (ML0411) for detection of antibodies in leprosy patients.

The potential of the recombinant serine-rich 45-kDa antigen (ML0411) of Mycobacterium leprae to aid in detecting M. leprae-specific serum antibodies was assessed by an enzyme-linked immunosorbent assay (ELISA) in leprosy patients and controls comprising of tuberculosis patients, other unrelated skin-diseased patients and healthy individuals from India. All 18 multibacillary (MB) and 18/38 (47.4%) of the paucibacillary (PB) leprosy patients were found positive. None of the controls was positive, yielding complete (0/49) specificity in the series tested here. On the other hand, an anti-phenolic glycolipid-1 (PGL-I) antibody-detecting assay yielded detectable responses in 94.4% (17/18) of MB and 36.8% (14/38) of PB leprosy patients. Only two of 49 (4.1%) controls were positive, giving a specificity of 95.9%. Further, there was a good concordance (agreement of 83.8%; chi(2) = 40.3, P < 0.001; kappa = 0.63) between the two assays. Thus, the 45-kDa-based assay was slightly better than anti-PGL-I antibody-detecting assay. Interestingly, when combining the results of both the assays together for all leprosy patients (MB + PB), the combined sensitivity was significantly higher than that of the anti-PGL-I antibody-detecting ELISA alone (73.2% versus 55.4%; P < 0.05), but not (P > 0.05) compared with the 45-kDa antigen-based assay alone. Similarly, in case of PB patients, using both assays in combination, the sensitivity was significantly higher compared with anti-PGL-I antibody-detecting assay alone (60.5% versus 36.8%; P < 0.05). While adopting the combinatorial approach, the specificity remained invariably high (>95%). In conclusion, the results of the present study indicate that the M. leprae 45-kDa protein is a potent B-cell antigen and may be a useful serodiagnostic reagent.

Antibodies, Bacterial↗

PubMed2006

Diabetes mellitus is strongly associated with tuberculosis in Indonesia.

SETTING: Diabetes mellitus is a known risk factor for tuberculosis (TB), but no studies have been reported from South-East Asia, which has a high burden of TB and a rapidly growing prevalence of diabetes. OBJECTIVE: To examine if and to what extent diabetes is associated with an increased risk of TB in an urban setting in Indonesia. DESIGN: Case-control study comparing the prevalence of diabetes mellitus (fasting blood glucose level >126 mg/dl) among newly diagnosed pulmonary TB patients and matched neighbourhood controls. RESULTS: Patients and control subjects had a similar age (median 30 years) and sex distribution (52% male), but malnutrition was more common among TB patients (median body mass index 17.7 vs. 21.5 kg/m2). HIV infection was uncommon (1.5% of patients). Diabetes mellitus was present in 60 of 454 TB patients (13.2%) and 18 of 556 (3.2%) control subjects (OR 4.7; 95%CI 2.7-8.1). Adjustment for possible confounding factors did not reduce the risk estimates. Following anti-tuberculosis treatment, hyperglycaemia reverted in a minority (3.7%) of TB patients. CONCLUSION: Diabetes mellitus is strongly associated with TB in young and non-obese subjects in an urban setting in Indonesia. This may have implications for TB control and patient care in this region.

Adult↗

PubMed2005

T cell immune responses to mycobacterial antigens in Brazilian tuberculosis patients and controls.

Production of IFN-gamma guarantees helpful T cell-mediated immunity against Mycobacterium tuberculosis infection. We have evaluated the in vitro immune responses to M. tuberculosis antigens using IFN-gamma production among 43 Brazilian tuberculosis (TB) patients prior to and after specific treatment, and 18 community controls. Peripheral blood mononuclear cells (PBMC) were cultivated in the presence either of purified protein derivative, ferritin, 10 kDa, 38 kDa, MPT59, Ag85A or Ag85B. Also, the two M. tuberculosis and M. bovis heat-shock proteins (hsp) 65 and 70 kDa were compared, and 5 day supernatants were harvested for cytokine detection by ELISA. The results showed that the overall profile of primary PBMC in response to most M. tuberculosis antigens was well correlated, since high IFN-gamma levels were induced by Ag85A, Ag85B, 38 kDa, ferritin and 10 kDa, as well as M. tuberculosis hsp65 in TB patients. In addition, analysis was carried out of the in vitro expression of activation molecules on lymphocytes, as CD25 and CD69 expression assessed in 17 TB patients showed induction on CD4+ T cells by Ag85B. Overall, significantly low responses were found in untreated, in comparison with the treated TB patients. Furthermore, internal community but not healthy control individuals have higher immune responses than do TB patients.

Adolescent↗

PubMed2005

Detection of in vitro interferon-gamma and serum tumour necrosis factor-alpha in multidrug-resistant tuberculosis patients.

Multidrug-resistant tuberculosis (MDR-TB) is known as having a poor prognosis with a weak response to therapy and very high death rates. The aim of this work was to assess the immune response to the RD1-encoded antigen ESAT-6 of Mycobacterium tuberculosis in MDR-TB patients and compare to non-resistant (NR) TB patients and healthy controls (HC). Evaluation of interferon (IFN)-gamma production showed that, although 55% of the MDR patients were responsive to ESAT-6, they produced lower IFN-gamma levels (553 +/- 11 pg/ml) when compared to NR-TB (1179 +/- 163 pg/ml; P < 0.05) but not to controls (412 +/- 65.7 pg/ml). Differences in the response to ESAT-6 and to its overlapping peptides mixture were also significant between MDR versus treated pulmonary NR-TB. Furthermore, a very low rate of response to PPD (23.5%) and to Ag85B (33.3%) was noted in MDR-TB patients as compared to the other groups. To determine the inflammatory response in patients' groups, detection of tumour necrosis factor (TNF)-alpha was assessed in their sera before and during chemotherapy. Mean TNF-alpha levels in MDR-TB (43.8 +/- 9 pg/ml) paralleled those found in treated pulmonary, and it was significantly different (P < 0.05) from the values found in untreated NR and HC. Interestingly, secretion of IFN-gamma and TNF-alpha were predominant in MDR patients who presented with bilateral pulmonary lesions and lung cavitation. The present data indicate that the overall immune response to mycobacterial antigens is decreased in resistant TB and the major role inflammatory cytokines may play in perpetuating pulmonary tissue damage.

Adult↗

PubMed2004

Is there a future for TNF promoter polymorphisms?

The in vitro study of TNF promoter polymorphism (SNP) function was stimulated by the numerous case-control (association) studies of the polymorphisms in relation to human disease and the appearance of several studies claiming to show a functional role for these SNPs provided a further impetus to researchers interested in the role of TNF in their disease of interest. In this review we consider case-control studies, concentrating on the autoimmune and inflammatory diseases rheumatoid arthritis, multiple sclerosis, ankylosing spondylitis, and asthma, and on infectious diseases including malaria, hepatitis B and C infection, leprosy and sepsis/septic shock. We also review the available evidence on the functional role of the various TNF promoter polymorphisms. In general, case-control studies have produced mixed results, with little consensus in most cases on whether any TNF polymorphisms are actually associated with disease, although results have been more consistent in the case of infectious diseases, particularly malaria. Functional studies have also produced mixed results but recent work suggests that the much studied -308G/A polymorphism is not functional, while the function of other TNF polymorphisms remains controversial. Studies of the TNF region are increasingly using extended haplotypes that can better capture the variation of the MHC region.

Autoimmune Diseases↗

PubMed2004

Interleukin-10 promoter single-nucleotide polymorphisms as markers for disease susceptibility and disease severity in leprosy.

We have determined IL-10 promoter genotypes of five single-nucleotide polymorphisms (SNPs): T-3575A, A-2849G, C-2763A, -A-1082G and C-819T. The haplotype frequencies were defined in healthy subjects compared to leprosy patients, and analyzed for their occurrence in multi- (MB) vs paucibacillary (PB) as severe and mild forms of leprosy, respectively. Haplotypes defined by three SNP positions (-3575, -2849 and -2763) captured significant differences between controls and patients (P=0.04). The haplotype carrying -3575A, -2849G and -2763C was associated with resistance to leprosy and to the development of severe forms of the disease using either a binomial (controls vs cases, P=0.005, OR=0.35, CI=0.13-0.91) or ordinal (controls vs PB vs MB, P=0.006, OR=0.32, CI=0.12-0.83) model. By contrast, the IL-10 haplotype -3575T/-2849A/-2763C was found to be associated with susceptibility to leprosy per se (P=0.027, OR=2.37, CI=1.04-5.39), but not leprosy type. The data suggest that the IL-10 locus contributes to the outcome of leprosy.

Confidence Intervals↗

PubMed2004

Immunological crossreactivity of the Mycobacterium leprae CFP-10 with its homologue in Mycobacterium tuberculosis.

Mycobacterium tuberculosis culture filtrate protein-10 (CFP-10) (Rv3874) is considered a promising antigen for the immunodiagnosis of tuberculosis (TB) together with early secreted antigens of M. tuberculosis (ESAT-6). Both ESAT-6 and CFP-10 are encoded by the RD1 region that is deleted from all tested M. bovis bacille Calmette-Guérin (BCG) strains but present in M. leprae, M. tuberculosis, M. bovis, M. kansasii, M. africanum and M. marinum. In this study, the homologue of CFP-10 in M. leprae (ML0050) is identified and characterized. Interferon-gamma production in response to this homologue by T cells from leprosy patients, TB patients and unexposed controls shows that CFP-10 of M. leprae is a potent antigen that crossreacts with CFP-10 of M. tuberculosis at the T-cell level. This crossreactivity has implications for the use of CFP-10 of these mycobacterial species as diagnostic tool in areas endemic for both the diseases.

Amino Acid Sequence↗

PubMed2004

Pneumonia caused by Mycobacterium kansasii in a series of patients without recognised immune defect.

The clinical and epidemiological characteristics of 17 patients diagnosed with Mycobacterium kansasii pneumonia within a limited geographical region over a period of 10 years are described. An in-depth evaluation of the innate and adaptive immune systems was performed for five available patients. A comparison was made of the genetic fingerprint patterns of the isolates obtained by restriction fragment length polymorphism (RFLP) analysis, with the major polymorphic tandem repeat (MPTR) as a probe. Predisposing factors consisted of smoking, airway abnormalities, substance abuse, diabetes or poor general condition, but in two patients no risk factor was identified. In the five patients tested, no abnormalities or deficiencies were detected in the innate or adaptive type-1 immunity. All M. kansasii isolates had identical MPTR RFLP patterns, although no epidemiological connection could be established, and these were identical to those of clinical isolates from Australian patients. These data do not support the theory that defects in the innate or adaptive type-1 immunity have a role in the pathogenesis of invasive M. kansasii infections. The identical fingerprint patterns of the isolates suggested the existence of a virulent strain of M. kansasii.

Adult↗

PubMed2002

Human T cell responses to peptides of the Mycobacterium leprae 45-kD serine-rich antigen.

In order to identify T cell epitopes within the Mycobacterium leprae 45-kD serine-rich antigen, we analysed responses to overlapping 17-mer peptides encompassing the whole antigen in non-exposed UK controls, Pakistani leprosy patients and tuberculosis patients in both the United Kingdom and Pakistan. This antigen has been described as M. leprae-specific, although it has a hypothetical homologue in M. tuberculosis. Human peripheral blood mononuclear cells were stimulated with peptide for 5 days and IFN-gamma measured in supernatants by ELISA. Some peptides were recognized more frequently by T cells from tuberculoid leprosy patients than those from UK controls, suggesting that such T cell epitopes might have diagnostic potential, while other peptides induced greater responses among UK control subjects. Short-term cell lines confirmed that these assays detected specific T cell recognition of these peptides. However, many tuberculosis patients also recognized these potentially specific peptides suggesting that there could be a true homologue present in M. tuberculosis.

Amino Acid Sequence↗

PubMed2002

Heterogeneity in the granulomatous response to mycobacterial infection in patients with defined genetic mutations in the interleukin 12-dependent interferon-gamma production pathway.

Patients with genetic lesions in the Type-1 cytokine/cytokine receptor pathway exhibit a selective susceptibility to severe infections with poorly pathogenic mycobacteria and non-typhi salmonella spp. These experiments of nature demonstrate that IL-12-dependent IFNgamma production is critical for granuloma formation and therefore host immunity against such pathogens. The essential role of granuloma formation for protective immunity to these organisms is emphasized by the differing granuloma forming capabilities and resultant clinical sequelae observed in these patients which seems to reflect their ability to produce or respond to IFNgamma (Fig. 9). At one pole of this spectrum, represented by the complete IFNgammaR1/2 deficient patients, there is a complete absence of mature granuloma formation, whereas with the less severe mutations (i.e. partial IFNgammaR1/2, complete IL-12p40 and complete IL-12Rbeta1 deficiency), granuloma formation is very heterogenous with wide variations in composition being observed. This suggests that in the latter individuals, who produce partial but suboptimal IFNgamma responses, other influences, including pathogen virulence and host genotype may also affect the type and scale of the cellular response elicited.

Genetic Predisposition to Disease↗