Comparative Analysis of Mycobacterial Heat Shock Proteins-Induced Apoptosis of Peripheral Blood Mononuclear Cells in Sarcoidosis and Tuberculosis

T-cell signature cytokines distinguish pulmonary sarcoidosis from pulmonary tuberculosis

Sarcoidosis is a systemic inflammatory disorder characterized by tissue infiltration due to mononuclear phagocytes and lymphocytes and associated noncaseating granuloma formation. Pulmonary sarcoidosis (PS) shares a number of clinical, radiological, and histopathological characteristics with that of pulmonary tuberculosis (PTB). Due to this, clinicians face issues in differentiating between PS and PTB in a substantial number of cases. There is a lack of any specific biomarker that can diagnose PS distinctively from PTB. We compared T-cell-based signature cytokines in patients with PS and PTB. In this study, we proposed a serum biomarker panel consisting of cytokines from cells: T helper (Th) 1 [interferon-gamma (IFN-γ); tumor necrosis factor-alpha (TNF-α)], Th9 [interleukin (IL)-9], Th17 [IL-17], and T regulatory (Treg) [IL-10; transforming growth factor-beta (TGF-β)]. We performed the principal component analysis that demonstrated that our serum cytokine panel has a significant predictive ability to differentiate PS from PTB. Our results could aid clinicians to improve the diagnostic workflow for patients with PS in TB endemic settings where the diagnosis between PS and PTB is often ambiguous.

Comparative Analysis of Fcγ and Complement Receptors Presence on Monocytes in Pulmonary Sarcoidosis and Tuberculosis

Sarcoidosis (SA) is a granulomatous disorder, which mostly affects the lungs. Its clinical characteristics resemble tuberculosis (TB), but its treatment is different. The etiology of SA is unknown; however, mycobacterial antigens were proposed as environmental factors in its development. Due to previously revealed immunocomplexemia with mycobacterial antigens in the blood of our SA but not TB patients, and in the search for biomarkers for differential diagnosis of the two disorders, we studied the phagocytic activity of monocytes from both patients' groups with flow cytometry. With the use of this method, we also analyzed the occurrence of receptors for IgG (FcγR) and complement components (CR) at the surface of these monocytes, responsible for phagocytosis of immunocomplexes. We revealed a higher phagocytic activity of monocytes in both disorders, but an increased frequency of monocytes with FcγRIII (CD16) and decreased with CR1 (CD35) receptor in the blood of SA vs. TB patients. With regard to our other genetic study on FcγRIII variants in SA and TB, this may account for the decreased clearance of immunocomplexes and different immune responses in the two diseases. Thus, the presented analysis not only sheds light on the pathomechanisms of SA and TB but may also support their differential diagnosis.

Comparative Analysis of FCGR Gene Polymorphism in Pulmonary Sarcoidosis and Tuberculosis

The clinical outcome of sarcoidosis (SA) is very similar to tuberculosis (TB); however, they are treated differently and should not be confused. In search for their biomarkers, we have previously revealed changes in the phagocytic activity of monocytes in sarcoidosis and tuberculosis. On these monocytes we found a higher expression of receptors for the Fc fragment of immunoglobulin G (FcγR) in SA and TB patients vs. healthy controls. FcγRs are responsible for the binding of immune complexes (ICs) to initiate an (auto)immune response and for ICs clearance. Surprisingly, our SA patients had a high blood level of ICs, despite the abundant presence of FcγRs. It pointed to FcγR disfunction, presumably caused by the polymorphism of their (FCGR) genes. Therefore, we present here an analysis of the occurrence of FCGR2A, FCGR2B, FCGR2C, FCGR3A and FCGR3B variants in Caucasian SA and TB patients, and healthy individuals with the use of polymerase chain reaction (PCR) and real-time PCR. The presented data point to a possibility of supporting the differential diagnosis of SA and TB by analyzing FCGR2C, FCGR3A and FCGR3B polymorphism, while for severe stages of SA also by studying FCGR2A variants. Additionally, the genotyping of FCGR2A and FCGR3B might serve as a marker of SA progression.

Mycobacterial Heat Shock Proteins in Sarcoidosis and Tuberculosis

Pathological similarities between sarcoidosis (SA) and tuberculosis (TB) suggest the role of mycobacterial antigens in the etiopathogenesis of SA. The Dubaniewicz group revealed that not whole mycobacteria, but Mtb-HSP70, Mtb-HSP 65, and Mtb-HSP16 were detected in the lymph nodes, sera, and precipitated immune complexes in patients with SA and TB. In SA, the Mtb-HSP16 concentration was higher than that of Mtb-HSP70 and that of Mtb-HSP65, whereas in TB, the Mtb-HSP16 level was increased vs. Mtb-HSP70. A high Mtb-HSP16 level, induced by low dose-dependent nitrate/nitrite (NOx), may develop a mycobacterial or propionibacterial genetic dormancy program in SA. In contrast to TB, increased peroxynitrite concentration in supernatants of peripheral blood mononuclear cell cultures treated with Mtb-HSP may explain the low level of NOx detected in SA. In contrast to TB, monocytes in SA were resistant to Mtb-HSP-induced apoptosis, and CD4+T cell apoptosis was increased. Mtb-HSP-induced apoptosis of CD8+T cells was reduced in all tested groups. In Mtb-HSP-stimulated T cells, lower CD8+γδ+IL-4+T cell frequency with increased TNF-α,IL-6,IL-10 and decreased INF-γ,IL-2,IL-4 production were present in SA, as opposed to an increased presence of CD4+γδ+TCR cells with increased TNF-α,IL-6 levels in TB, vs. controls. Mtb-HSP modulating the level of co-stimulatory molecules, regulatory cells, apoptosis, clonal deletion, epitope spread, polyclonal activation and molecular mimicry between human and microbial HSPs may also participate in the induction of autoimmunity, considered in SA. In conclusion, in different genetically predisposed hosts, the same antigens, e.g., Mtb-HSP, may induce the development of TB or SA, including an autoimmune response in sarcoidosis.

Immune dysregulation and pathogenic pathways mediated by common infections in rheumatoid arthritis

Rheumatoid arthritis (RA) is one of the world's most prevalent inflammatory autoimmune diseases, affecting between 0.4 and 1.3% of the population. The susceptibility to RA appears to be influenced by a complex interaction between a favorable genetic background and the existence of a specific immune reaction against a wide range of environmental variables. Among the known environmental variables, infections are believed to have a significant role in promoting the formation of autoimmune disorders, which are frequently caused by specific microorganisms. Infections have been linked to RA in recent medical studies. In this study, we selected the most prevalent infections associated with RA from the literature and described the data confirming their pathogenic role in RA. Our investigation included Mycobacterium, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Proteus mirabilis, Epstein-Barr virus, parvovirus, and Prevotella copri.

A Rare Case of Henoch-Schönlein Purpura and Mycobacterium xenopi Pulmonary Infection

Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis with cutaneous, articular, gastrointestinal, and renal manifestations. Leukocytoclastic vasculitis and IgA deposits are classically found when involved skin and kidneys are biopsied. The disease's etiology remains unknown, although many bacterial and viral infections have been described as triggering factors.

A 53-year-old woman presented with fever, arthralgia, and non-thrombocytopenic purpura. She also had a segmental pulmonary collection with peripheral alveolar consolidation. Staphylococcus aureus and mycobacteria growth was found on sputum cultures. In addition to intravenous antibiotics and anti-mycotic drugs, high-dose corticosteroids were urgently administered due to the development of severe intestinal symptoms. A cutaneous biopsy later confirmed HSP. Microbial identification yielded Mycobacterium xenopi.

In the review of the literature, we only found 12 cases of Mycobacterium tuberculosis and one case of Mycobacterium avium-intracellulare complex that were associated with HSP. Nearly, half of the cases responded to anti-mycotic treatment alone. The rest required immunosuppressants. 

We report the first case of M. xenopi pulmonary infection in HSP. This disease process can have a severe course, which requires rapid recognition and treatment.

Role of Infections in the Pathogenesis of Rheumatoid Arthritis: Focus on Mycobacteria

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease characterized by chronic erosive polyarthritis. A complex interaction between a favorable genetic background, and the presence of a specific immune response against a broad-spectrum of environmental factors seems to play a role in determining susceptibility to RA. Among different pathogens, mycobacteria (including Mycobacterium avium subspecies paratuberculosis, MAP), and Epstein–Barr virus (EBV), have extensively been proposed to promote specific cellular and humoral response in susceptible individuals, by activating pathways linked to RA development. In this review, we discuss the available experimental and clinical evidence on the interplay between mycobacterial and EBV infections, and the development of the immune dysregulation in RA.

Host-microbe interactions in the pathogenesis and clinical course of sarcoidosis

Sarcoidosis is a rare inflammatory disease characterized by the development of granulomas in various organs, especially in the lungs and lymph nodes. Clinics of the disease largely depends on the organ involved and may range from mild symptoms to life threatening manifestations. Over the last two decades, significant advances in the diagnosis, clinical assessment and treatment of sarcoidosis have been achieved, however, the precise etiology of this disease remains unknown. Current evidence suggests that, in genetically predisposed individuals, an excessive immune response to unknown antigen/s is crucial for the development of sarcoidosis. Epidemiological and microbiological studies suggest that, at least in a fraction of patients, microbes or their products may trigger the immune response leading to sarcoid granuloma formation. In this article, we discuss the scientific evidence on the interaction of microbes with immune cells that may be implicated in the immunopathogenesis of sarcoidosis, and highlight recent studies exploring potential implications of human microbiota in the pathogenesis and the clinical course of sarcoidosis.

Mycobacterium tuberculosis: An Adaptable Pathogen Associated With Multiple Human Diseases

Mycobacterium tuberculosis, the etiological agent of tuberculosis (TB), is an extremely successful pathogen that adapts to survive within the host. During the latency phase of infection, M. tuberculosis employs a range of effector proteins to be cloud the host immune system and shapes its lifestyle to reside in granulomas, sophisticated, and organized structures of immune cells that are established by the host in response to persistent infection. While normally being restrained in immunocompetent hosts, M. tuberculosis within granulomas can cause the recrudescence of TB when host immunity is compromised. Aside from causing TB, accumulating evidence suggests that M. tuberculosis is also associated with multiple other human diseases, such as pulmonary complications, autoimmune diseases, and metabolic syndromes. Furthermore, it has been recently appreciated that M. tuberculosis infection can also reciprocally interact with the human microbiome, which has a strong link to immune balance and health. In this review, we highlight the adaptive survival of M. tuberculosis within the host and provide an overview for regulatory mechanisms underlying interactions between M. tuberculosis infection and multiple important human diseases. A better understanding of how M. tuberculosis regulates the host immune system to cause TB and reciprocally regulates other human diseases is critical for developing rational treatments to better control TB and help alleviate its associated comorbidities.

Prevalence of chronic pulmonary aspergillosis in patients with tuberculosis from Iran

In patients with preexisting lung disease, especially a cavity, Aspergillus can infect the surface of the cavity, causing chronic cavitary pulmonary aspergillosis (CCPA), and may form an aspergilloma, collectively called chronic pulmonary aspergillosis (CPA). In the present study, we assessed tuberculosis (TB) patients for CPA based on culture and serological methods. During a period of 1 year (from March 2013 to March 2014), we studied 124 patients with TB (94 with current TB and 30 with previous TB) at Masih Daneshvari Hospital in Tehran, Iran. Sputum specimens were analyzed by direct microscopic examination (DME) and fungal culture. The clinical and radiological features of all patients were recorded, to categorize the patients into CCPA and aspergilloma. All patients were screened for serum-specific IgG against A. fumigatus, by enzyme-linked immunosorbent assay (ELISA). Out of 124 patients with TB (66 male, age range: 10-91 years), 48 patients (38.7 %) exhibited residual cavities. Eighteen (14.5 %) patients had cavities with pleural thickening. A round-shaped mass lesion was detected in six patients (6.8 %). DME was positive in ten patients for septate fungal hyphae. A. fumigatus was grown from 14 samples. Fifty-five (44.3 %) cases were positive for serum-specific IgG against A. fumigatus. Of 124 patients with TB, 3 (2.4 %) met criteria for aspergilloma and 14 (11.3 %) for CCPA. CPA is a common clinical presentation in individuals with healed TB in Iran, as reported by previous studies from other countries.

Mycobacteria and autoimmunity

Mycobacterial infections can cause a variety of different manifestations. The increasing incidence of these infections worldwide brought another medical dilemma: immunological manifestations characterized by the presence of many autoantibodies and concomitant presence of autoimmune diseases. The burden of tuberculosis reactivation that emerged with immunosuppressive therapy worsened with the growing use of biological disease-modifying antirheumatic drugs (DMARDs). This review will address the relationship between the immune system and mycobacteria.

Annexin A11 (ANXA11) gene polymorphisms are associated with sarcoidosis in a Han Chinese population: a case-control study

OBJECTIVES

To further identify the single-nucleotide polymorphisms (SNPs) that contribute to the genetic susceptibility to sarcoidosis, we examined the potential association between sarcoidosis and 15 SNPs of the ANXA11 gene.

DESIGN

A case-control study.

SETTING

A tuberculosis unit in a hospital of the university in China.

PARTICIPANTS

Participants included 412 patients with sarcoidosis and 418 healthy controls.

METHODS

The selected SNPs were genotyped using the MALDI-TOF in the MassARRAY system.

RESULTS

Statistically significant differences were found in the allelic or genotypic frequencies of the rs2789679, rs1049550 and rs2819941 in the ANXA11 gene between patients with sarcoidosis and controls. The rs2789679 A allele (p=0.00004, OR=1.42, 95% CI 1.17 to 1.73) and rs2819941 T allele (p=0.0006, OR=1.41, 95% CI 1.16 to 1.71) were significantly more frequent in patients with sarcoidosis compared with controls. The frequency of the rs1049550 T allele (p=0.000002, OR=0.61, 95% CI 0.49 to 0.74) in patients with sarcoidosis was significantly lower than that in controls. The multi-SNP model reveals that rs1049550 is the only independent SNP association effect after accounting for the other two marginally associated SNPs. In block 2 (rs1049550-rs2573351), the T-C haplotype occurred significantly less frequently (p=0.001), whereas the C-C haplotypes occurred more frequently (p=0.0001) in patients with sarcoidosis than controls. Furthermore, genotype frequency distribution revealed that, in rs1049550, the CC genotype was significantly more in patients with chest X-ray (CXR) stage I sarcoidosis than in patients with CXR stage II-IV sarcoidosis (p=0.012).

CONCLUSIONS

These findings point to a role for the polymorphisms of ANXA11 in sarcoidosis in a Chinese Han population, and may be informative for future genetic studies on sarcoidosis.

Polymorphism of FCGR3A gene in sarcoidosis

We showed increased level of immune complexes (ICs) with mycobacterial heat shock proteins (Mtb-hsp) and increased expression of receptors for Fc fragment of immunoglobulin G (FcγR) I-III on blood monocytes with their increased phagocytic activity, responsible for clearance of these ICs in sarcoidosis (SA). Since FcγRIIIa is the most crucial in this process, we genotyped 77 SA patients and 143 healthy controls with polymerase chain reaction for V158F polymorphism of FCGR3A gene, encoding FcγRIIIa. We revealed significantly higher percentage of 158F and 158FF and lower of 158FV variants in Stage I of SA versus controls. Conversely, in Stage II of SA, we found increase in 158VV homozygotes versus controls. We also showed significant increase of 158F and 158FF variants in Stage I vs II and of 158V in Stage II vs I. Therefore, in Stage I, 158F allele may cause decreased FcγRIIIa affinity and clearance of ICs, whereas in Stage II, 158V allele may cause effective FcγRIIIa affinity to ICs with e.g. mycobacteria, their phagocytosis, Mtb-hsp secretion with ICs formation, Mtb-hsp epitope spread and subsequent immune reaction. Thus, V158F polymorphism of FCGR3A may explain the immunocomplexemia in our patients and might serve as prognostic marker of clinical course of sarcoidosis.

Endostatin and cathepsin-V in bronchoalveolar lavage fluid of patients with pulmonary sarcoidosis

Recently, it has been reported that lack of cathepsins prevent the development of lung granulomas in a mouse model of Besnier-Boeck-Schaumann (BBS) disease, sarcoidosis. There is no data about cathepsin V (Cath V) in bronchoalveolar lavage fluid (BALF) in humans. Endostatin is a novel inhibitor of lung epithelial cells. The role of this protein in BBS is not determined. The aim of this study was to evaluate the concentration of endostatin, Cath V, and IL-18 in BALF of BBS patients. We studied 22 BBS patients (Stage 2). The control group consisted of 20 healthy subjects. Cath V concentration was lower in BBS than in healthy group (16.03±8.60 vs. 32.25±21.90 pg/ml, p=0.004). Both endostatin and IL-18 levels were higher in BBS than in the control group (0.88±0.30 vs. 0.29±0.04 ng/ml, p=0.028; 40.37±31.60 vs. 14.61±1.30 pg/ml, p=0.007, respectively). In BBS there were correlations between the levels of endostatin and IL-18 (r=0.74, p=0.001) as well as endostatin and DLCO (diffusing capacity for carbon monoxide) (r=-0.6, p=0.013). Receiver-operating characteristic (ROC) curves were applied to find the cut-off for the BALF levels of Cath V, endostatin, and IL-18. We conclude that Cath V and endostatin may represent an index of pulmonary sarcoidosis activity.

Microbial and human heat shock proteins as 'danger signals' in sarcoidosis

In the light of the Matzinger's model of immune response, human heat shock proteins (HSPs) as main 'danger signals' (tissue damage-associated molecular patterns-DAMPs) or/and microbial HSPs as pathogen-associated molecular patterns (PAMPs) recognized by pattern recognition receptors (PRR), may induce sarcoid granuloma by both infectious and non-infectious factors in genetically different predisposed host. Regarding infectious causes of sarcoid models, low-virulence strains of, e.g. mycobacteria and propionibacteria recognized through changed PRR and persisting in altered host phagocytes, generate increased release of both human and microbial HSPs with their molecular and functional homology. High chronic spread of human and microbial HSPs altering cytokines, co-stimulatory molecules, and Tregs expression, apoptosis, oxidative stress, induces the autoimmunity, considered in sarcoidosis. Regarding non-infectious causes of sarcoidosis, human HSPs may be released at high levels during chronic low-grade exposure to misfolding amyloid precursor protein in stressed cells, phagocyted metal fumes, pigments with/without aluminum in tattoos, and due to heat shock in firefighters. Therefore, human HSPs as DAMPs and/or microbial HSPs as PAMPs produced as a result of non-infectious and infectious factors may induce different models of sarcoidosis, depending on the genetic background of the host. The number/expression of PRRs/ligands may influence the occurrence of sarcoidosis in particular organs.

S Fas in bronchoalveolar lavage fluid of patients with sarcoidosis in relation to cigarette smoking

Sarcoidosis is a multiorgan granulomatous disease with frequent spontaneous remission. Apoptosis is postulated to participate in the granuloma resolution. Soluble Fas (sFas) is known to inhibit Fas-induced apoptosis. The aim of this study was to determine the sFas concentration in the BALf of ever smoking (S) and never smoking (NS) patients with sarcoidosis. We investigated 57 patients with confirmed SA: 36 NS and 21 S. The sFas concentration was measured by ELISA method. The sFas concentration was lower in the BALf of patients S group compared with NS (median values 68.3 vs. 96.1 pg/mL, p=0.07) and it was significantly lower in active smokers when compared with NS (62.9 vs. 96.1 pg/mL, p=0.03). There was a significant correlation between sFas concentration and proportion of lymphocytes and negative relation with macrophage proportion. Lower concentration of sFas in smoking SA patients may result in higher apoptosis rate of inflammatory cells and hereby promote resolution of granulomas.

Is mycobacterial heat shock protein 16 kDa, a marker of the dormant stage of Mycobacterium tuberculosis, a sarcoid antigen?

We demonstrated opposite presence of mycobacterial heat shock proteins (Mtb-hsp) 70 kDa, 65 kDa, 16 kDa in sera and lymph nodes in sarcoidosis (SA). Higher occurrence of serum Mtb-hsp70 than Mtb-hsp 65 and Mtb-hsp 16 could be caused by sequestration of Mtb-hsp 65 and Mtb-hsp 16 in circulating immune complexes (CIs). It is possible that in genetically different predisposed hosts, Mtb-hsp 16 induced by dose-dependent nitrate/nitrite (NOx) may be involved in latent tuberculosis (TB), active TB, or SA development. We evaluated Mtb-hsp 70, Mtb-hsp 65, Mtb-hsp 16 presence in precipitated CIs and serum NOx level in 20 SA patients, 19 TB patients, and 21 healthy volunteers using PEG precipitation, Western Blot, and Griess methods. We revealed higher NOx concentrations in SA and TB than in controls, but lower in SA than TB. Mtb-hsp 16, Mtb-hsp 65, and Mtb-hsp70 concentrations in precipitated CIs were higher in SA than in TB and controls. In all tested groups, Mtb-hsp 16 concentration was higher than Mtb-hsp70 and Mtb-hsp 65. We suggest that lower levels of NOx may induce a M. tuberculosis genetic dormancy program via higher Mtb-hsp 16 expression in SA. It seems that Mtb-hsp 16 may be more important than Mtb-hsp70 and Mtb-hsp 65 in CIs formation and initiate an autoimmune response in SA related to mycobacteria's stationary-phase.

The sarcoid granuloma: 'epithelioid' or 'lymphocytic-epithelioid' granuloma?

Background

This study aims to analyze the structure and quantities of cellular elements in sarcoid granulomas.

Methods

We investigated 34 transbronchial lung biopsy samples obtained from 34 sarcoid patients. The quantity and composition of the cellular elements inside a granuloma were determined by the quantitative stereometry method, employing the numerical density as a stereological method.

Results

A total of 102 sarcoid granulomas were analyzed. The central part of all granulomas was occupied by epithelioid cells. Besides these, giant cells, lymphocytes, macrophages and plasma cells were also seen. The mean numerical density of all the cells in the central part of a sarcoid granuloma was 111,751 mm^-3. Lymphocytes prevailed in number, exceeding the total count of all other cells. With a mean numerical density of 74,321 mm^-3, lymphocytes were twice as numerous as both epithelioid cells and macrophages with a mean numerical density of 37,193 mm^-3.

Conclusions

Lymphocytes are the predominant cell type in the central part of a sarcoid granuloma, significantly exceeding both epithelioid cells and macrophages in number, raising the question if the term “epithelioid granuloma”, routinely used to designate sarcoid granulomas, is correct, or if it would be more logical to call them “lymphocytic-epithelioid granulomas” instead.

Trial registration

This study was supported by the Serbian Ministry of Science and Environmental Protection Grant Number 175006/2011.

Changed phagocytic activity and pattern of Fcγ and complement receptors on blood monocytes in sarcoidosis

We have recently revealed that mycobacterial heat shock proteins (Mtb-hsp), involved in forming of immune complexes (CIs), can induce immune response in sarcoidosis (SA). The complexemia may result from inappropriate phagocytosis and clearance of CIs by monocytes with following persistent antigenemia and granuloma formation. Because an aberrant expression of receptors for Fc fragment of immunoglobulin G (FcγR) and complement receptors (CR) on monocytes can be involved in this process, we have evaluated the expression of FcγRI (CD64), FcγRII (CD32), FcγRIII (CD16) and CR1 (CD35), CR3 (CD11b), CR4 (CD11c) receptors on blood CD14(+) monocytes and its phagocytic activity in 24 patients with SA and 20 healthy volunteers using flow cytometry. We found significantly increased expression of all examined FcγR and decreased expression of CD35 and CD11c on CD14(+) monocytes in SA patients vs controls. Significantly increased percentage of CD14(+)CD16(+)CD35(-), CD14(+)CD64(+)CD35(+), CD14(+)CD64(+)CD11b(+), CD14(+)CD64(+)CD11c(+) and decreased of CD14(+)CD32(-)CD35(+), CD14(+)CD32(-)CD11b(+), CD14(+)CD32(-)CD11c(+) monocytes' phenotypes was revealed in SA. The total number and percentage of phagocyting monocytes was significantly increased in SA as compared with controls. In conclusion, altered expression of FcγR and CR on CD14(+) monocytes and its increased phagocytic activity may be responsible for high antigen load, persistent antigenemia and immunocomplexemia in SA patients.

Mycobacterial heat shock protein-induced blood T lymphocytes subsets and cytokine pattern: comparison of sarcoidosis with tuberculosis and healthy controls

BACKGROUND AND OBJECTIVE

Sarcoidosis (SA) is a disorder of unknown aetiology. Mycobacterium tuberculosis heat shock proteins (Mtb-hsp) have been considered as causative agents of SA. The role of Mtb-hsp in the immune response in SA has not been investigated.

METHODS

Mtb-hsp-stimulated T-cell subsets and Th1/Th2 cytokine patterns in the supernatant from peripheral blood mononuclear cell cultures from 22 SA patients, 20 tuberculosis (TB) patients and 20 healthy volunteers were compared using flow cytometry.

RESULTS

In unstimulated cultures, a significantly higher percentage of CD8(+)alphabeta(+)T-cells were present in SA versus controls. Similarly there was a significantly increased IL-6 and decreased IL-4 level in SA and significantly lower INF-gamma, IL-2, IL-4, IL-10 production in TB versus controls. After Mtb-hsp stimulation, there was a significantly increased TNF-alpha, IL-6, IL-10 and decreased INF-gamma, IL-2, IL-4 production in SA and significantly increased TNF-alpha, IL-6 concentrations in TB versus controls. CD8(+)gammadelta(+)IL-4(+)T-cells were detected significantly less often in Mtb-hsp-induced cultures in SA versus controls. Comparing SA versus TB, CD4(+)gammadelta(+)TCR-cells were significantly increased in Mtb-hsp-induced cultures in TB versus controls and SA. Before stimulation, significantly increased IL-6, IL-10 and decreased IL-4 level in SA versus TB was revealed, whereas Mtb-hsp stimulation caused significantly increased IL-10 and decreased IL-4 concentrations in SA.

CONCLUSIONS

After Mtb-hsp stimulation, increased levels of pro-inflammatory cytokines, TNF-alpha and IL-6 were found in sera from SA and TB patients in comparison with healthy controls; SA patients demonstrated the lowest levels of IL-4 and the highest levels of IL-10.