Differential expression of HLA-G and ILT-2 receptor in human tuberculosis: Localized versus disseminated disease.

Human leukocyte antigen-G (HLA-G) is an anti-inflammatory and immunosuppressive molecule that can modulate immune cell activation. The role of HLA-G in tuberculosis, an immune-mediated and chronic bacterial disease remains to be elucidated. We investigated the expression profile of soluble and membrane bound HLA-G in pulmonary TB (PTB), TB pleural effusion (TB-PE, localized disease) and Miliary TB (disseminated form). The expression of HLA-G receptor, ILT-2 was also determined on the immune cells. We observed that the plasma sHLA-G levels were significantly increased in Miliary TB than in TB-PE patients. In contrast, immunophenotyping revealed that the percent frequency of CD3(+) T cells expressing HLA-G was significantly reduced in Miliary TB as compared to TB-PE, whereas frequency of CD14(+) monocytes expressing HLA-G was significantly higher in TB-PE patients. Strikingly in the TB-PE cases, comparison of disease site, i.e. pleural effusion with peripheral blood showed increased expression of both soluble and surface HLA-G, whereas ILT-2 expressing cells were reduced at the local disease site. Furthermore, we demonstrated that in TB-PE cases, HLA-G expression on CD3(+) T cells was influenced by broad spectrum MMP inhibitor. Thus, differential expression of HLA-G could potentially be a useful biomarker to distinguish different states of TB disease.

Interferon-gamma gene+874T-A polymorphism is associated with tuberculosis and gamma interferon response.

Interferon-gamma is the most important cytokine in resistance to mycobacterial diseases and common variants of interferon-gamma gene could be related to tuberculosis susceptibility. We tested the hypothesis that the interferon-gamma+874T-A polymorphism is associated with tuberculosis disease, and affects the interferon-gamma response. We determined by pyrosequencing the distribution of the interferon-gamma+874T-A polymorphism in a Turkish population of 319 patients with pulmonary tuberculosis, 42 children with severe forms of tuberculosis and 115 healthy donors. We also analysed whether any correlation exists between this polymorphism and interferon-gamma response to Mycobacterium tuberculosis antigens by ELISPOT in 58 pulmonary tuberculosis cases, and the results were analysed according to the genotypes. We found that the minor allele (T) frequency was significantly lower in patients with pulmonary tuberculosis when compared to controls (P=0.024, OR=0.7), a similarly significant decrease in the frequency of TT genotype was observed in patients with pulmonary tuberculosis, compared to the control group (P=0.02, OR=0.49). IFN-gamma responses to PPD antigen in TT genotype was found to be significantly higher than the AA group (P>0.001). Non-parametric correlation analysis of ELISPOT data showed significant reverse correlation in PPD, CFP10 and ESAT6 values and IFN-gamma +874 genotypes. These results show that the IFN-gamma +874T-A polymorphism is related to the IFN-gamma response and the magnitude of the response decreases during transition from TT- to TA and to AA genotypes. Our data suggest that similar to various Caucasian populations, in a Turkish population the IFN-gamma+874 T-A polymorphism is also associated with tuberculosis disease and affects the magnitude of the IFN-gamma response.

Cytokine gene polymorphisms in Colombian patients with different clinical presentations of tuberculosis.

Tuberculosis (TB) has different clinical presentations. Pulmonary TB affects only the lungs and exhibits variable anti-mycobacterial immune responses. Pleural TB is a localized disease with a strong immune response. Miliary TB is a disseminated form with poor immune response. Cytokines play a pivotal role in anti-mycobacterial response and may determine the type of TB. Thus, gene polymorphisms associated with cytokine production may be associated with clinical presentations of TB. In this study, 54 tuberculin-negative healthy controls, 81 tuberculin-positive healthy controls, 140 patients with pulmonary TB, 30 with pleural TB and 20 with miliary TB were studied. Single nucleotide polymorphisms were typed for tumour necrosis factor-alpha, interferon-gamma (IFN-gamma), transforming growth factor-beta1, interleukin-10 (IL-10) and interleukin-6 by sequence-specific primer polymerase chain reaction (SSP-PCR). Allelic, genotypic and haplotypic associations with clinical forms of TB were evaluated. IL-10 -1082 A/A genotype and IFNgamma+874 T allele were associated with pleural TB. Seventy-five extended genotypes were found; two differed between patients and controls, and two between groups of patients. Results suggest that IL-10 low-producer polymorphism and IFN-gamma high-producer polymorphism are associated with pleural TB.

CD14 gene promoter polymorphism in different clinical forms of tuberculosis.

Mycobacterium tuberculosis interacts with monocyte-macrophages through cell surface molecules including CD14. A soluble form of CD14 (sCD14) exists in human serum, and higher amounts of it are found in tuberculosis. A polymorphism on CD14 gene promoter was associated with increased sCD14 levels in some diseases. To evaluate whether this polymorphism associates with tuberculosis, its clinical forms, and increased sCD14, genotype/allele frequencies in tuberculosis patients were compared with the controls. Results confirmed increased levels of sCD14 in patients with tuberculosis, and those with miliary tuberculosis had the highest levels. sCD14 decreased to normal levels after anti-tuberculosis treatment. No association was found between the CD14 polymorphism and tuberculosis or sCD14 levels. Results suggest that sCD14 may be involved in anti-tuberculosis immune response, but its increase is a consequence of infection rather than a predisposed genetic trait. Measuring sCD14 in tuberculosis may help monitor anti-tuberculosis treatment.

Evaluation of the polymerase chain reaction in the diagnosis of miliary tuberculosis in bone marrow smear.

OBJECTIVE: Miliary tuberculosis (MTB) is difficult to diagnose. When prompt diagnosis is necessary, the polymerase chain reaction (PCR) to detect mycobacterial DNA may be valuable. SETTING: Tuberculosis clinic in an academic tertiary-level hospital in Mexico. DESIGN: Bone marrow (BM) aspiration samples from 30 consecutive clinically suspected MTB patients and 58 non-tuberculosis hematologic patients were evaluated by in-house PCR using a fragment of the insertion sequence IS6110; results were compared with those obtained by acid-fast-stained smears, culture in Löwenstein-Jensen medium, histology, and serology. RESULTS: Tuberculosis diagnosis was confirmed in all MTB suspects, 28 by microscopy and culture in pulmonary or extra-pulmonary samples other than BM, and two by clinical and radiologic improvement after antituberculosis treatment. In fresh BM specimens, in-house PCR was positive in 21/30 (70%) suspects, contrasting with only one positive (3.3%) in staining and culture, and four with compatible histologic findings (13.3%). BM samples from the control group showed negative results in bacteriologic and histologic studies, except in nine who had positive PCR results. These nine control cases had malignant processes. CONCLUSION: PCR in aspirates of BM is a useful diagnostic assay in cases of MTB, mainly when bacteriological results are negative.

Clinical and genetic heterogeneity of inherited autosomal recessive susceptibility to disseminated Mycobacterium bovis bacille calmette-guérin infection.

Five patients from 4 unrelated Tunisian families who presented with disseminated neonatal infection by Mycobacterium bovis bacille Calmette-Guérin strain were investigated. Two unrelated patients had different homozygous interleukin-12 receptor beta1 subunit gene splice-site mutations (64+5G-->A and 550-2A-->G). Two siblings and 1 unrelated patient, all of whom were from the same town, carried the same mutation (297del8) within the interleukin-12p40 gene. This is the first description of familial cytokine deficiency reported so far. All patients had complete lack of expression of the affected polypeptide and a profound deficiency of in vitro interferon-gamma production. The clinical severity of the mycobacterial infection was heterogeneous, even among affected members of the same family, which suggests the intervention of modifying genes.

[The immunological and cytogenetic changes in patients with pulmonary tuberculosis]. / Immunologicheskie i tsitogeneticheskie izmeneniia u bol'nykh tuberkulezom legkikh.

The performed studies showed that patients with active phase pulmonary tuberculosis have their T-system function suppressed, that of B-system activated, this phenomenon being the most marked in those patients with fibrocavernous tuberculosis. Increase in the activity of phagocytes was more common in patients with infiltrative tuberculosis. The immunity system state in subjects with non-active post tuberculous alterations did not depart from normal values. DNA and RNA concentrations were decreased in those patients having more pronounced immunologic disturbances (infiltrative and fibrocavernous tuberculosis), reparative capacity of RNA being altered only in patients with focal tuberculosis. Strong correlation was established between immunologic and cytogenetic indices.

Active tuberculosis undiagnosed until autopsy.

In this report 21 patients in whom tuberculosis was the primary cause of death, but which was not diagnosed until necropsy, are reviewed. Of the 21 deaths, 11 were due to pulmonary tuberculosis and 10 to miliary tuberculosis. Proper evaluation of the following factors might have led to the correct diagnosis in many of the patients: A family history of tuberculosis, prior pleurisy, a gastrectomy, diabetes mellitus or end-stage renal failure; all can be associated with an increased incidence of tuberculosis. A negative tuberculin skin reaction does not exclude the presence of active tuberculosis. In the search for Mycobacterium tuberculosis, the examination of just one or two sputum specimens is not an adequate bacteriologic investigation. A positive gastric smear can have diagnostic importance. Ascitic fluid findings can be characteristic of tuberculous peritonitis. A negative bone marrow aspirate for acid-fast bacilli does not exclude miliary tuberculosis. Significant anemia, high fever and leukopenia increases the possibility of tuberculosis. The persistence and/or progression of lung infiltration, irrespective of supposedly specific antibiotic therapy, strongly suggests tuberculosis. Miliary tuberculosis can present as an adult respiratory distress syndrome. All but one patient in this series had fever. the failure to diminish the pyrexia believed due to specific lung infections with presumably effective antibiotics, and the inability of therapy to control other conditions thought to cause the fever indicate the presence of tuberculosis. Tuberculosis, especially miliary disease, should be considered as a possible etiology of fever of unknown origin. If the diagnosis of tuberculosis is highly suggestive, even without bacteriologic confirmation, a therapeutic trial of antituberculosis drugs should be given.