The Immuno-endocrine Component in the Pathogenesis of Tuberculosis

Association between Disgust Sensitivity during Pregnancy and Endogenous Steroids: A Longitudinal Study

The emotion of disgust protects individuals against pathogens, and it has been found to be elevated during pregnancy. Physiological mechanisms discussed in relation to these changes include immune markers and progesterone levels. This study aimed to assess the association between steroids and disgust sensitivity in pregnancy. Using a prospective longitudinal design, we analyzed blood serum steroid concentrations and measured disgust sensitivity via text-based questionnaires in a sample of 179 pregnant women during their first and third trimesters. We found positive correlations between disgust sensitivity and the levels of C19 steroids (including testosterone) and its precursors in the Δ5 pathway (androstenediol, DHEA, and their sulfates) and the Δ4 pathway (androstenedione). Additionally, positive correlations were observed with 5α/β-reduced C19 steroid metabolites in both trimesters. In the first trimester, disgust sensitivity was positively associated with 17-hydroxypregnanolone and with some estrogens. In the third trimester, positive associations were observed with cortisol and immunoprotective Δ5 C19 7α/β-hydroxy-steroids. Our findings show that disgust sensitivity is positively correlated with immunomodulatory steroids, and in the third trimester, with steroids which may be related to potential maternal-anxiety-related symptoms. This study highlights the complex relationship between hormonal changes and disgust sensitivity during pregnancy.

A comprehensive review of the new FIGO classification of ovulatory disorders

BACKGROUND

The World Health Organization (WHO) system for the classification of disorders of ovulation was produced 50 years ago and, by international consensus, has been updated by the International Federation of Gynecology and Obstetrics (FIGO).

OBJECTIVE AND RATIONALE

This review outlines in detail each component of the FIGO HyPO-P (hypothalamic, pituitary, ovarian, PCOS) classification with a concise description of each cause, and thereby provides a systematic method for diagnosis and management.

SEARCH METHODS

We searched the published articles in the PubMed database in the English-language literature until October 2022, containing the keywords ovulatory disorders; ovulatory dysfunction; anovulation, and each subheading in the FIGO HyPO-P classification. We did not include abstracts or conference proceedings because the data are usually difficult to assess.

OUTCOMES

We present the most comprehensive review of all disorders of ovulation, published systematically according to the logical FIGO classification.

WIDER IMPLICATIONS

Improving the diagnosis of an individual's ovulatory dysfunction will significantly impact clinical practice by enabling healthcare practitioners to make a precise diagnosis and plan appropriate management.

Steroid immune responsive gene regulation in Mycobacterium tuberculosis infection in vitro

Tuberculosis (TB) is an infectious disease displaying a multifactorial pathology. The immunomodulatory role attributed to steroid hormones, such as vitamin D3 (VD3) and 17β-estradiol (E2), highlighted the importance of these hormones against Mycobacterium tuberculosis (Mtb) infection. In order to understand their influence upon gene expression of immune and inflammatory responsive genes against Mtb we tested it in vitro using peripheral blood mononuclear cells (PBMCs). Cells were pretreated with VD3 (50 ng/mL) or E2 (100 nM/mL) and co-cultured with H37Rv Mtb or stimulated with lipopolysaccharide from Escherichia coli (LPS). After 24 h and 72 h of co-culture the Mtb viability in macrophages test was performed, as well the total RNA isolation for gene expression analysis by RT-qPCR of the following target genes: NLRP3, DC-SIGN, IL-1β, and IL-10. We also measured IL-10, TNF, IFN-γ, IL-4, IL-6, and IL-2 supernatant levels. As the main results, we found that VD3 and E2 downregulated the expression of inflammatory genes NLRP3, IL-1β, and IL-10 expression in Mtb co-cultured cells. Finally, VD3 treatment increased the release of the cytokine IFN-γ in Mtb-infected cells, while E2 treatment inhibited the release of IL-10, TNF, IFN-γ, and IL-6. Therefore, we report an immunogenetic influence of VD3 and E2 upon Mtb co-culture.

Characterization of Longitudinal Testosterone, Cortisol, and Musth in Male Asian Elephants (Elephas maximus), Effects of Aging, and Adrenal Responses to Social Changes and Health Events

Simple Summary

The conservation of endangered species and sustainability of managed populations requires good health and welfare of individuals. Male elephants experience a biological phenomenon called “musth”, characterized by a suite of physiological and behavioral changes which serve to facilitate copulation between the sexes, but can also pose unique challenges under human care. This study characterized longitudinal patterns of circulating testosterone and cortisol in relation to musth in four adult Asian elephant bulls and assessed age-related effects on musth activity and adrenal responses to social changes and clinical health events. All bulls exhibited regular annual musth cycles, and there was no clear evidence of chronically elevated cortisol secretion outside of musth. Circulating cortisol covaried positively with testosterone and musth, highlighting intrinsic patterns that should be considered when evaluating the impact of changes on adrenal glucocorticoid activity. Testosterone decreased with age in sexually mature bulls, whereas age-related changes in cortisol varied across individuals, with the three older bulls showing the greatest rate of change during musth. Changes in cortisol were associated with treatment for Mycobacterium tuberculosis in two bulls, but not with activation of disease. In contrast to physiological factors, there was no evidence that social changes involving male herdmates impacted adrenal glucocorticoid activity in the short term. This study highlights the importance of longitudinal hormone monitoring to track changes in physiological function and identify factors that may influence welfare, which is important for making more informed decisions on how to manage male elephants under varying degrees of human care.

Abstract

The conservation of endangered species and sustainability of managed populations requires considerations to ensure the health and welfare of individuals. Male elephants experience a biological phenomenon called “musth”, which is characterized by increased testosterone production, temporal gland secretion and urine dribbling, heightened aggression and sexual behavior, and therefore can pose unique challenges for human safety and animal welfare. This study characterized longitudinal (9 to 22 years) patterns of circulating testosterone and cortisol in relation to musth in four adult Asian elephant bulls spanning ages from 12 to 54 years. Age-related effects on musth activity and adrenal responses to social changes and clinical health events were also examined. All bulls exhibited regular annual musth cycles. Circulating cortisol covaried positively with testosterone and musth, highlighting intrinsic patterns that should be considered when evaluating the impact of social, health, and environmental changes on adrenal glucocorticoid activity. Except for an end-of-life cortisol increase in one bull, there was no clear evidence of chronically elevated cortisol secretion outside of musth in any individual. Testosterone decreased with age in sexually mature bulls, whereas age-related changes in cortisol varied across individuals, with the three older bulls showing the greatest rate of change during musth versus inter-musth periods. In contrast to physiological factors, there was no evidence of social factors, such as addition of a new male and death of male herdmates, impacting adrenal glucocorticoid activity in these bulls in the short term. Changes in cortisol were associated with treatment for Mycobacterium tuberculosis (M. tb) in two bulls, increasing after start of treatment and decreasing with cessation of treatment, but were not clearly associated with activation of disease. This study highlights the importance of longitudinal hormone monitoring to track changes in physiological function and responses to social, health, and environmental change in elephant bulls, which is important for making more informed decisions on how to manage male elephants under varying degrees of human care to ensure welfare and safety.

Estradiol inhibits autophagy of Mycobacterium tuberculosis‑infected 16HBE cells and controls the proliferation of intracellular Mycobacterium tuberculosis

Tracheobronchial tuberculosis (TBTB) is most common in young, middle-aged females. Despite adequate anti-tuberculosis therapy, >90% of patients develop tracheobronchial stenosis, which has a high rate of resulting in disability. The present study aimed to explore the effect of estradiol on the development of TBTB. Estrogen receptor (ER) expression in granulomatous tissue was assessed via immunofluorescence. In order to determine whether estrogen affected the proliferation of intracellular Mycobacterium tuberculosis (Mtb), 16HBE cells were infected with Mtb in vitro, followed by estradiol treatment. Intracellular Mtb was quantified via colony counting. The effect of estradiol on autophagy of infected 16HBE cells was determined via western blotting and transmission electron microscopy. Necrosis assays of infected 16HBE cells were analyzed using propidium iodide staining and assessing lactate dehydrogenase (LDH) release. To determine how estradiol affects autophagy, infected 16HBE cells were treated with ER-specific and non-specific modulators. Reactive oxygen species (ROS) levels were analyzed via flow cytometry. Additionally, the protein expression levels of autophagy-associated proteins were determined via western blotting. Mtb could enter human lobar bronchial goblet cells and ciliated cells in patients with TBTB. The results also demonstrated that ERα was expressed in granulomatous tissue from patients with TBTB. Administration of 10⁻⁶ M estradiol reduced the number of intracellular Mtb colony-forming units in vitro in the 16HBE human bronchial epithelial cell line at day 3 after infection. Furthermore, cells treated with estradiol and infected with Mtb released less LDH at 72 h and exhibited reduced necrosis levels at 24 h compared with the untreated cells. In addition, autophagy of infected 16HBE cells was inhibited by estradiol. Estradiol and the specific ERα agonist had similar effects on autophagy in infected 16HBE cells. Additionally, treatment with the ERα antagonist abolished the inhibition of autophagy by estradiol in infected 16BHE cells. Compared with the untreated infected 16HBE cells, the ROS levels in the infected 16HBE cells treated with estradiol and the ERα agonist significantly decreased. The levels of phosphorylated (p)-mTOR and p-AKT notably increased in estradiol- and ERα agonist-treated infected 16HBE cells. In summary, estradiol may serve a key role in the development of TBTB through binding to ERα.

The Impact of a Knowledge Discovery-Based Psychoanalytic Intervention in the Treatment of Tuberculosis in University Students with Different Doses of Isoniazid

Tuberculosis (TB) is an infectious disease that poses a serious threat to the health of the population in China, and TB outbreaks in universities have aroused great concern in society. Psychological emotions have a large impact on the academic lives of university students, and nowadays it is not only labour-intensive but also slow to monitor and analyse and deal with the psychology of university students' daily lives in a uniform manner. If psychological problems are not detected and given feedback in a timely manner, they can have a series of negative effects on the individual university student. In this paper, we apply the Bi-LSTM model and the CNN model neural network algorithm to learn the text data, and finally have 95.55% and 90.03% accuracy in the sentiment analysis experiment, respectively, which provides a feasible solution to solve the batch rapid analysis of the psychological changes reflected in the daily text of university students. Risk communication for TB emergencies should emphasize public participation, timely release of information about the epidemic, and good monitoring of public opinion.

The Role of Thyroid Hormones in the Differential Diagnosis of Tuberculous and Parapneumonic Pleural Effusions

BACKGROUND

The differential diagnosis of tuberculous pleural effusion (TPE) and parapneumonic pleural effusion (PPE) is challenging due to similar clinical manifestations and body fluid biochemical profiles. Thyroid hormone levels change in response to lymphocyte proliferation in the peripheral blood of patients with mycobacterial infections such as tuberculosis; therefore, this study aimed to investigate the utility of assessing thyroid hormone levels to aid in the differential diagnosis of TPE and PPE.

METHODS

We measured free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) levels in the pleural effusions of 59 newly admitted patients (32 and 27 with TPE and PPE, respectively). Hormone levels were assessed using an electrochemiluminescence technique, and the diagnostic parameters for tuberculosis were evaluated. Differences in hormone levels between patients with TPE and PPE were assessed by t-tests, and their diagnostic value for a differential diagnosis was evaluated by receiver operating characteristic curve analyses.

RESULTS

FT3 and FT4 levels in patients with TPE were significantly higher than those in patients with PPE (p < 0.01 and p < 0.05, respectively), whereas TSH expression did not significantly differ between the two groups (p > 0.05). FT3 and FT4 levels showed no correlation with sex or history of smoking, although FT3 levels decreased with age. The highest sensitivity was observed for the quantification of FT3 levels (84.38%).

CONCLUSIONS

Increased FT3 and FT4 levels could potentially be used for the differential diagnosis of TPE and PPE.

Infection-Associated Thymic Atrophy

The thymus is a vital organ of the immune system that plays an essential role in thymocyte development and maturation. Thymic atrophy occurs with age (physiological thymic atrophy) or as a result of viral, bacterial, parasitic or fungal infection (pathological thymic atrophy). Thymic atrophy directly results in loss of thymocytes and/or destruction of the thymic architecture, and indirectly leads to a decrease in naïve T cells and limited T cell receptor diversity. Thus, it is important to recognize the causes and mechanisms that induce thymic atrophy. In this review, we highlight current progress in infection-associated pathogenic thymic atrophy and discuss its possible mechanisms. In addition, we discuss whether extracellular vesicles/exosomes could be potential carriers of pathogenic substances to the thymus, and potential drugs for the treatment of thymic atrophy. Having acknowledged that most current research is limited to serological aspects, we look forward to the possibility of extending future work regarding the impact of neural modulation on thymic atrophy.

The Functional Significance of Endocrine-immune Interactions in Health and Disease

Hormones are known to influence various body systems that include skeletal, cardiac, digestive, excretory, and immune systems. Emerging investigations suggest the key role played by secretions of endocrine glands in immune cell differentiation, proliferation, activation, and memory attributes of the immune system. The link between steroid hormones such as glucocorticoids and inflammation is widely known. However, the role of peptide hormones and amino acid derivatives such as growth and thyroid hormones, prolactin, dopamine, and thymopoietin in regulating the functioning of the immune system remains unclear. Here, we reviewed the findings pertinent to the functional role of hormone-immune interactions in health and disease and proposed perspective directions for translational research in the field.

Immune variations throughout the course of tuberculosis treatment and its relationship with adrenal hormone changes in HIV-1 patients co-infected with Mycobacterium tuberculosis

HIV infection is a major risk factor predisposing for Mycobacterium tuberculosis infection and progression to active tuberculosis (TB). As host immune response defines the course of infection, we aimed to identify immuno-endocrine changes over six-months of anti-TB chemotherapy in HIV+ people. Plasma levels of cortisol, DHEA and DHEA-S, percentages of CD4⁺ regulatory T cell subsets and number of IFN-γ-secreting cells were determined. Several cytokines, chemokines and C-reactive protein levels were measured. Results were correlated with clinical parameters as predictors of infection resolution and compared to similar data from HIV+ individuals, HIV-infected persons with latent TB infection and healthy donors. Throughout the course of anti-TB/HIV treatment, DHEA and DHEA-S plasma levels raised while cortisol diminished, which correlated to predictive factors of infection resolution. Furthermore, the balance between cortisol and DHEA, together with clinical assessment, may be considered as an indicator of clinical outcome after anti-TB treatment in HIV+ individuals. Clinical improvement was associated with reduced frequency of unconventional Tregs, increment in IFN-γ-secreting cells, diminution of systemic inflammation and changes of circulating cytokines and chemokines. This study suggests that the combined anti-HIV/TB therapies result in partial restoration of both, immune function and adrenal hormone plasma levels.

Evidence for a More Disrupted Immune-Endocrine Relation and Cortisol Immunologic Influences in the Context of Tuberculosis and Type 2 Diabetes Comorbidity

Pulmonary tuberculosis (PTB), caused by Mycobacterium tuberculosis (Mtb), is a major health problem worldwide, further aggravated by the convergence of type 2 diabetes mellitus (DM) which constitutes an important risk factor for TB development. The worse scenario of patients with PTB and DM may be partly related to a more unbalanced defensive response. As such, newly diagnosed PTB patients with DM (TB+DM, n = 11) or not (TB, n = 21), as well as DM (n = 18) patients and pair matched controls (Co, n = 22), were investigated for the circulating immuno-endocrine-metabolic profile (ELISA), along with studies in peripheral blood mononuclear cells (PBMC) analyzing transcript expression (RT-qPCR) of mediators involved in glucocorticoid functionality. Given the hyperglycemic/hypercortisolemic scenario of TB+DM patients, PBMC were also exposed to stress-related cortisol concentrations (0.1 and 1 μM) and supraphysiologic glucose doses (10, 20, and 40 mM) and assessed for the specific response against Mtb stimulation (lymphoproliferation, -thymidine incorporation-, and cytokine production -bead-cytometry). All TB patients displayed increased plasma amounts of cortisol, growth hormone -hGH-, and proinflammatory mediators. In turn, TB+DM showed even higher levels of interferon gamma -IFN-γ- and hGH (vs. TB), or IL-6, C reactive protein, cortisol and hGH (vs. DM). Both DM groups had equally augmented values of IL-10. All TB patients showed decreased dehydroepiandrosterone- sulfate concentrations, even more in TB+DM cases. Leptin was also decreased in both TB cases, particularly in the TB group, revealing a lower body mass index, as well. Unlike PBMC from TB cases showing a decreased relationship between the glucocorticoids receptor (GR) isoforms (GRα/GRβ; functional isoform/negative isoform), cells from TB+DM patients had no changes in this regard, along with an increased expression of 11-beta hydroxysteroid dehydrogenase type-1, the enzyme facilitating intracellular cortisone to cortisol conversion. TB+DM patients also showed an increased Mtb antigen-driven lymphoproliferation. Compared to TB, DM and HCo counterparts, PBMC from TB+DM patients had a biased Th1 response to Mtb stimulation (increased IL-2 and IFN-γ production), even when exposed to inhibitory cortisol doses. TB+DM patients show a more unbalanced immuno-endocrine relationship, respect the non-diabetic counterparts, with a relative deficiency of cortisol immunomodulatory influences, despite their more favorable microenvironment for cortisol-mediated immune effects.

Stress Hyperglycemia in Patients with Tuberculosis Disease: Epidemiology and Clinical Implications

PURPOSE OF REVIEW

The intersection of tuberculosis (TB) disease and type 2 diabetes mellitus is severely hindering global efforts to reduce TB burdens. Diabetes increases the risk of developing TB disease and negatively impacts TB treatment outcomes including culture conversion time, mortality risk, and TB relapse. Recent evidence also indicates plausible mechanisms by which TB disease may influence the pathogenesis and incidence of diabetes. We review the epidemiology of stress hyperglycemia in patients with TB and the pathophysiologic responses to TB disease that are related to established mechanisms of stress hyperglycemia. We also consider clinical implications of stress hyperglycemia on TB treatment, and the role of TB disease on risk of diabetes post-TB.

RECENT FINDINGS

Among patients with TB disease, the development of stress hyperglycemia may influence the clinical manifestation and treatment response of some patients and can complicate diabetes diagnosis. Research is needed to elucidate the relationship between TB disease and stress hyperglycemia and determine the extent to which stress hyperglycemia impacts TB treatment response. Currently, there is insufficient data to support clinical recommendations for glucose control among patients with TB disease, representing a major barrier for efforts to improve treatment outcomes for patients with TB and diabetes.

Determination of dehydroepiandrosterone and its biologically active oxygenated metabolites in human plasma evinces a hormonal imbalance during HIV-TB coinfection

An estimated one third of the world's population is affected by latent tuberculosis (TB), which once active represents a leading cause of death among infectious diseases. Human immunodeficiency virus (HIV) infection is a main predisposing factor to TB reactivation. Individuals HIV-TB co-infected develop a chronic state of inflammation associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation. This results in a hormonal imbalance, disturbing the physiological levels of cortisol and dehydroepiandrosterone (DHEA). DHEA and its oxygenated metabolites androstenediol (AED), androstenetriol (AET) and 7-oxo-DHEA are immunomodulatory compounds that may regulate physiopathology in HIV-TB co-infection. In order to study possible changes in plasma levels of these hormones, we developed an approach based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). To our knowledge, this represents the first report of their simultaneous measurement in HIV-TB individuals and the comparison with healthy donors, obtaining statistically higher plasma levels of DHEA, AET and 7-oxo-DHEA in patients. Moreover, we found that concentrations of 7-oxo-DHEA positively correlated with absolute CD4+ T cell counts, nadir CD4+ T cell values and with individuals who presented TB restricted to the lungs. This research contributes to understanding the role of these hormones in HIV-TB and emphasizes the importance of deepening their study in this context.

Cytokine Biomarkers Associated with Human Extra-Pulmonary Tuberculosis Clinical Strains and Symptoms

Background: The primary site of infection for Mycobacterium tuberculosis (Mtb) is the alveolar macrophages. However, Mtb can disseminate into other organs and causes extrapulmonary tuberculosis (EPTB). The diagnosis of EPTB is challenging due to relatively inaccessible infectious sites that may be paucibacillary and with clinical symptoms varying by site that are similar to those seen in other diseases. Hence, we sought to identify the expression patterns of a variety of cytokines that may be specific to EPTB from in vitro infections and in the plasma of TB patients. Methods: To define those cytokine secretions associated with EPTB, human THP-1 derived macrophages were first infected with Mtb clinical isolates from pulmonary and EPTB. Infected macrophages supernatants were harvested at different time points and cytokines known to play key roles in TB immune responses including TNF-α, IL-6, IL-10, IFN-γ, and VEGF-A were measured by ELISA. Those cytokines that were in vitro associated to EPTB were also measured in the plasma from patients with PTB, EPTB, non-EPTB-confirmed-like symptoms and healthy controls. Results: While all of the studied cytokine secretions varied after in vitro infection, higher levels of TNF-α and VEGF secretions were observed in vitro in the infected macrophages respectively in the PTB and EPTB infecting clinical isolates. Similar trends were observed from the plasma of patients where patients with PTB showed significantly higher level of TNF-α compared to EPTB and healthy control groups. The patients with EPTB showed higher plasma level of VEGF compared to those patients with the non-EPTB (p < 0.01) and to healthy controls group (p < 0.0001). Using Receiver Operating Curves (ROC), we showed that TNF-α and VEGF concentrations could distinguish EPTB from non-confirmed EPTB with high sensitivity and specificity. Conclusion: Pulmonary and extrapulmonary Mtb clinical isolates showed different cytokine induction pattern in human macrophages that is also found in the plasma level of the EPTB patients. Further investigations are needed to define cytokine secretions that can lead to the definition of bio-signatures to differentiate EPTB from other pathologies with confusing symptoms that hampered the diagnosis of TB.

Study of adrenal function in patients with tuberculosis

BACKGROUND

Although subclinical adrenal insufficiency has been documented in tuberculosis but it has been neglected in mainstream management of TB due to inconclusive data on its prevalence in TB. The fact that adrenal insufficiency may result not only in poor general condition of the patient but also sudden death due to adrenal crisis, makes it all the more important to address this issue seriously. In this non-randomized interventional study comprising of 100 cases of TB, our aim was to assess the adreno-cortical functions in patients with pulmonary TB (50 cases) and extra-pulmonary TB (50 cases) in an attempt to determine if there is any compromise of adrenal function.

METHODS

In this study, 100 cases of active TB were investigated for adrenal insufficiency by measuring morning fasting basal serum cortisol levels, followed by low dose ACTH stimulation test using 1μg synacthen (synthetic ACTH analog). The post-stimulation serum cortisol levels were estimated. Basal serum cortisol levels<220nmol/L or post-stimulation test serum cortisol level increment<200nmol/L or post-stimulation serum cortisol levels<500nmol/L were suggestive of adrenal insufficiency.

RESULTS

Basal serum cortisol level was low in 16% cases and after low dose ACTH stimulation test, cortisol response was subnormal in 76% cases. Incidence of adrenal insufficiency in pulmonary TB (74%) and extra-pulmonary TB (78%) were comparable. The number of females having adrenal insufficiency in both the groups was higher than the males (67.3% males and 83.3% females) but the difference was statistically significant only in extra-pulmonary TB group (p=0.011). On analysing the data, the sensitivity of basal serum cortisol level estimation in diagnosing adrenal insufficiency was observed to be 21.05% and its specificity was 100%. Positive predictive value was 100% and negative predictive value was 28.57%. Diagnostic accuracy of basal serum cortisol level estimation was observed to be 40%.

CONCLUSION

The incidence of subclinical adrenal insufficiency in TB cases attending chest department at a tertiary care hospital was significantly high but comparable in both pulmonary and extra-pulmonary type of TB. Females in general and particularly those with extra-pulmonary TB were observed to be at increased risk of adrenal insufficiency. The low dose ACTH stimulation test was able to identify cases with adrenal insufficiency which had normal basal serum cortisol levels. Screening all TB cases for adrenal insufficiency by measuring both morning basal serum cortisol levels and low dose ACTH stimulation test can help identify cases at risk of fatal adrenal crisis and institute timely management, thus improving disease prognosis.

Patients With IgA Nephropathy Have Altered Levels of Immunomodulatory C19 Steroids. Glucocorticoid Therapy With Addition of Adrenal Androgens May Be the Choice

Glucocorticoid (GC) therapy is one of the methods of choices for treatment of autoimmune diseases (ADs). In addition, adrenal androgens are known as immunoprotective GC-antagonists. Adrenal steroids preferentially influence the Th1-components over the Th2 ones. We investigated steroid metabolome (using gas chromatography-mass spectrometry) in healthy controls (H), GC-untreated patients with ADs different from IgA nephropathy (U), GC-treated patients with ADs different from IgA nephropathy (T) and in patients with IgA nephropathy (IgAN), which were monitored on the beginning (N0), after one week (N1) and after one month (N2) of prednisolone therapy (60 mg of prednisolone/day/m2 of body surface). Between-group differences were assessed by one-way ANOVA, while the changes during the therapy were evaluated by repeated measures ANOVA. The ANOVA testing was followed by Duncan’s multiple comparisons. IgAN patients and patients with other ADs exhibited lack of adrenal androgens due to attenuated activity of adrenal zona reticularis (ZR). Androgen levels including their 7α-, 7β-, and 16α-hydroxy-metabolites were further restrained by GC-therapy. Based on these results and data from the literature, we addressed the question, whether a combination of GCs with Δ5-steroids or their more stable synthetic derivatives may be optimal for the treatment of antibodies-mediated ADs.

Changes in Host Immune-Endocrine Relationships during Tuberculosis Treatment in Patients with Cured and Failed Treatment Outcomes

A bidirectional communication between the immune and endocrine systems exists and facilitates optimum responses in the host during infections. This is in part achieved through changes in secretion patterns of hypothalamic hormones induced by inflammatory cytokines. The aim of this study was to elucidate the immune–endocrine alterations during tuberculosis (TB) treatment in patients with cured and failed TB treatment outcomes. Blood samples were collected from 27 cured and 10 failed patients and hormone as well as cytokine concentrations quantified at baseline, week 4, and month 6 of TB treatment. Hormone profiles of the two treatment outcome groups were different from each other prior to as well as during TB treatment. Treatment response effects were observed for cortisol, estradiol, T3, T4 ghrelin, leptin, amylin, adiponectin, and dehydroepiandrosterone (DHEA). Trends suggest that T4, amylin, and DHEA concentrations were different between treatment outcomes, although these did not reach statistical significance. Relationships between endocrine and inflammatory markers and the biological pathways involved differed between cured and failed treatment patients. These results highlight the complex interaction between the endocrine and immune system during active TB disease and throughout treatment and suggest that endocrine markers in conjunction with inflammatory markers may be useful in predicting unfavorable treatment outcomes.

Comparison of cortisol and thyroid hormones between tuberculosis-suspect and healthy elephants of Nepal

We compared cortisol and thyroid hormone (T3 and T4) concentrations between tuberculosis (TB)-suspected (n=10) and healthy (n=10) elephants of Nepal. Whole blood was collected from captive elephants throughout Nepal, and TB testing was performed using the ElephantTB STAT-PAK^® and DPP VetTB^® serological assays that detect antibodies against Mycobacterium tuberculosis and M. bovis in elephant serum. Cortisol, T3 and T4 were quantified by competitive enzyme immunoassays, and the results showed no significant differences in hormone concentrations between TB-suspect and healthy elephants. These preliminary data suggest neither adrenal nor thyroid function is altered by TB disease status. However, more elephants, including those positively diagnosed for TB by trunk wash cultures, need to be evaluated over time to confirm results.

Antibody profiles induced by Trypanosoma cruzi in chagasic patients with previous or current exposure to mycobacteria

Since the immune response mounted by the host to a particular microorganism might be influenced by the acquired immunological experience due to previous contact with other microorganisms, we performed a cross-sectional study to explore the pattern of Trypanosoma cruzi infection-related antibodies in T. cruzi-seropositive individuals presenting concomitant tuberculosis, or the antecedent of BCG vaccination. Sampled individuals were grouped as follows: patients with Chagas disease, not vaccinated with BCG, who further developed pulmonary tuberculosis; individuals with Chagas disease, BCG-vaccinated; and subjects with Chagas disease, presenting neither BCG scar nor tuberculosis disease. Non-vaccinated individuals or without tuberculosis, presented the highest values of anti-PH (P < 0.001), anti-FRA (P < 0.001), anti-p2β (P = 0.0023) and anti-B13 (P < 0.001) antibodies. The present findings constitute the first demonstration of the potential influence of concomitant tuberculosis on Chagas disease.

HIV-TB coinfection impairs CD8(+) T-cell differentiation and function while dehydroepiandrosterone improves cytotoxic antitubercular immune responses

Tuberculosis (TB) is the leading cause of death among HIV-positive patients. The decreasing frequencies of terminal effector (TTE ) CD8(+) T cells may increase reactivation risk in persons latently infected with Mycobacterium tuberculosis (Mtb). We have previously shown that dehydroepiandrosterone (DHEA) increases the protective antitubercular immune responses in HIV-TB patients. Here, we aimed to study Mtb-specific cytotoxicity, IFN-γ secretion, memory status of CD8(+) T cells, and their modulation by DHEA during HIV-TB coinfection. CD8(+) T cells from HIV-TB patients showed a more differentiated phenotype with diminished naïve and higher effector memory and TTE T-cell frequencies compared to healthy donors both in total and Mtb-specific CD8(+) T cells. Notably, CD8(+) T cells from HIV-TB patients displayed higher Terminal Effector (TTE ) CD45RA(dim) proportions with lower CD45RA expression levels, suggesting a not fully differentiated phenotype. Also, PD-1 expression levels on CD8(+) T cells from HIV-TB patients increased although restricted to the CD27(+) population. Interestingly, DHEA plasma levels positively correlated with TTE in CD8(+) T cells and in vitro DHEA treatment enhanced Mtb-specific cytotoxic responses and terminal differentiation in CD8(+) T cells from HIV-TB patients. Our data suggest that HIV-TB coinfection promotes a deficient CD8(+) T-cell differentiation, whereas DHEA may contribute to improving antitubercular immunity by enhancing CD8(+) T-cell functions during HIV-TB coinfection.

Relation of leptin, ghrelin and inflammatory cytokines with body mass index in pulmonary tuberculosis patients with and without type 2 diabetes mellitus

BACKGROUND

Pulmonary tuberculosis (TB) patients often suffer from anorexia and poor nutrition, causing weight loss. The peptide hormones leptin and its counterpart ghrelin, acting in the regulation of food intake and fat utilization, play an important role in nutritional balance. This study aimed to investigate the association of blood concentrations of leptin, ghrelin and inflammatory cytokines with body mass index (BMI) in TB patients with and without type 2 diabetes mellitus (T2DM).

METHODS

BMI, biochemical parameters and plasma levels of leptin, ghrelin and inflammatory cytokines were measured before the start of treatment in 27 incident TB patients with T2DM, 21 TB patients and 23 healthy subjects enrolled in this study.

RESULTS

The levels of leptin were significantly higher in TB patients (35.2 ± 19.1 ng/ml) than TB+T2DM (12.6 ± 6.1 ng/ml) and control (16.1 ± 11.1 ng/ml) groups. The level of ghrelin was significantly lower in TB (119.9 ± 46.1 pg/ml) and non-significantly lower in TB+T2DM (127.7 ± 38.6 pg/ml) groups than control (191.6 ± 86.5 pg/ml) group. The levels of TNF-α were higher, while IFN-γ and IL-6 levels were lower in patients than in the control group. Leptin showed a negative correlation with BMI in TB (r=-0.622, p<0.05) and TB+T2DM (r= -0.654, p<0.05) groups, but a positive correlation with BMI in the control group (r=0.521, p<0.05). Contrary ghrelin showed a positive correlation with BMI in TB (r=0.695, p<0.05) and TB+T2DM (r= 0.199, p>0.05) groups, but negative correlation with BMI in the control (r=-0.693, p<0.05) group. Inflammatory cytokines were poorly correlated with BMI in this study. Only IFN-γ showed a significant negative correlation with BMI in the control group (r=-0.545, p<0.05).

CONCLUSIONS

This study may suggest that possible abnormalities in ghrelin and leptin regulation (high levels of leptin and low levels of ghrelin) may be associated with low BMI and may account for the poor nutrition associated with TB and TB+T2DM.

The roles of microRNAs on tuberculosis infection: meaning or myth?

The central proteins for protection against tuberculosis are attributed to interferon-γ, tumor necrosis factor-α, interleukin (IL)-6 and IL-1β, while IL-10 primarily suppresses anti-mycobacterial responses. Several studies found alteration of expression profile of genes involved in anti-mycobacterial responses in macrophages and natural killer (NK) cells from active and latent tuberculosis and from tuberculosis and healthy controls. This alteration of cellular composition might be regulated by microRNAs (miRNAs). Albeit only 1% of the genomic transcripts in mammalian cells encode miRNA, they are predicted to control the activity of more than 60% of all protein-coding genes and they have a huge influence in pathogenesis theory, diagnosis and treatment approach to some diseases. Several miRNAs have been found to regulate T cell differentiation and function and have critical role in regulating the innate function of macrophages, dendritic cells and NK cells. Here, we have reviewed the role of miRNAs implicated in tuberculosis infection, especially related to their new roles in the molecular pathology of tuberculosis immunology and as new targets for future tuberculosis diagnostics.

The dual face of central nervous system tuberculosis: a new Janus Bifrons?

Tuberculosis (TB) is still a common infectious disease in developing countries, but it is also re-emerging in industrialized nations due to the HIV/AIDS pandemic. In addition to bacillary virulence, the host immune response plays a major role in the development of an active disease (either as a primary infection or reactivation) and in controlling the infection. Even though several mechanisms are involved in regulating the human immune response, biological environment seems to be determinant. In this context, the integrated neuro-immune-endocrine system strongly influences TB clinical outcome. One of the most important clinical aspects of TB is shown when the infection locates in the central nervous system (CNS), in which a very different set of immune responses is induced. Herein we review several aspects of the paradoxical immune response triggered during CNS-TB infection, and discuss the implications of this response in the cerebral infection outcome.

Adverse neuro-immune-endocrine interactions in patients with active tuberculosis

The nervous, endocrine and immune systems play a crucial role in maintaining homeostasis and interact with each other for a successful defensive strategy against injurious agents. However, the situation is different in long-term diseases with marked inflammation, in which defensive mechanisms become altered. In the case of tuberculosis (TB), this is highlighted by several facts: an imbalance of plasma immune and endocrine mediators, that results in an adverse environment for mounting an adequate response against mycobacteria and controlling inflammation; the demonstration that dehidroepiandrosterone (DHEA) secretion by a human adrenal cell line can be inhibited by culture supernatants from Mycobacterium tuberculosis-stimulated peripheral blood mononuclear cells - PBMC - of TB patients, with this effect being partly reverted when neutralizing transforming growth factor-β in such supernantants; the in vitro effects of adrenal steroids on the specific immune response of PBMC from TB patients, that is a cortisol inhibition of mycobacterial antigen-driven lymphoproliferation and interferon-γ production as well as a suppression of TGF-β production in DHEA-treated PBMC; and lastly the demonstration that immune and endocrine compounds participating in the regulation of energy sources and immune activity correlated with the consumption state of TB patients. Collectively, immune-endocrine disturbances of TB patients are involved in critical components of disease pathology with implications in the impaired clinical status and unfavorable disease outcome. This article is part of a Special Issue entitled 'Neuroinflammation in neurodegeneration and neurodysfunction'.

Non-invasive monitoring of glucocorticoid metabolites in banded mongooses (Mungos mungo) in response to physiological and biological challenges

Free-ranging banded mongooses are infected by the novel pathogen, Mycobacterium mungi in northern Botswana. A reliable method for determining stress-related physiological responses in banded mongooses will increase our understanding of the stress response in M. mungi infection. Therefore, our aim was to examine the suitability of four enzyme immunoassays (EIAs) for monitoring adrenocortical endocrine function in captive and free-ranging banded mongooses based on fecal glucocorticoid metabolite (FGM) analysis. A conducted adrenocorticotropic hormone challenge revealed suitability of a valid measurement of FGM levels in banded mongoose feces for all four tested EIAs, with an 11-oxoetiocholanolone assay detecting 11,17-dioxoandrostanes (11,17-DOA) performing best. Subsequent analyses using only this EIA showed the expected decrease in FGM concentrations 48 h after administering dexamethasone sodium phosphate. Furthermore, captive mongooses showed higher FGM concentrations during reproductive activity, agonistic encounters and depredation events. Finally, a late-stage, tuberculosis-infected moribund mongoose in a free-ranging troop had a 54-fold elevation in FGM levels relative to the rest of the troop. Measurements of gastrointestinal transit times and FGM metabolism post-defecation indicate that the time delay of FGM excretion approximately corresponded with food transit time and that FGM metabolism is minimal up to 8h post-defecation. The ability to reliably assess adrenocortical endocrine function in banded mongoose now provides a solid basis for advancing our understanding of infectious disease and endocrinology in this species.

Altered microRNA expression levels in mononuclear cells of patients with pulmonary and pleural tuberculosis and their relation with components of the immune response

Different lines of evidence demonstrate that microRNAs (miRNAs) play an important role in host-pathogen interactions. In this study we investigated the expression patterns of several miRNAs, most of them involved in regulating inflammatory responses, in patients with tuberculosis (TB). In order to understand the events occurring at the site of infection, we employed mononuclear cells obtained from both peripheral blood (PBMC) and pleural fluids (PFMC) of patients. Interestingly, we found that the miRNA signature of each compartment is different, with a strong down-regulation in PFMCs of miR-223, miR-144* and miR-421. In addition, we observed that miR-146a expression is also down-regulated in tuberculosis patients, both in PBMCs and PFMCs while miR-424 levels are elevated only in the peripheral compartments. We also showed that systemic expression of these miRNAs changes upon specific treatment and is associated with IL-6 levels, a cytokine playing a substantial role in TB immunopathology. Present results contribute to a better knowledge of the host responses in TB pathogenesis, pointing out the role of miRNAs in this disease.

Molecular and cellular mechanisms of Mycobacterium avium-induced thymic atrophy

Thymic atrophy has been described as a consequence of infection by several pathogens and shown to be induced through diverse mechanisms. Using the mouse model of Mycobacterium avium infection, we show in this study that the production of NO from IFN-γ-activated macrophages plays a major role in mycobacterial infection-induced thymic atrophy. Our results show that disseminated infection with a highly virulent strain of M. avium, but not with a low-virulence strain, led to a progressive thymic atrophy. Thymic involution was prevented in genetically manipulated mice unable to produce IFN-γ or the inducible NO synthase. In addition, mice with a selective impairment of IFN-γ signaling in macrophages were similarly protected from infection-induced thymic atrophy. A slight increase in the concentration of corticosterone was found in mice infected with the highly virulent strain, and thymocytes presented an increased susceptibility to dexamethasone-induced death during disseminated infection. The administration of an antagonist of glucocorticoid receptors partially reverted the infection-induced thymic atrophy. We observed a reduction in all thymocyte populations analyzed, including the earliest thymic precursors, suggesting a defect during thymic colonization by T cell precursors and/or during the differentiation of these cells in the bone marrow in addition to local demise of thymic cells. Our data suggest a complex picture underlying thymic atrophy during infection by M. avium with the participation of locally produced NO, endogenous corticosteroid activity, and reduced bone marrow seeding.

Immune responses in the lungs of patients with tuberculous pleural effusion without pulmonary tuberculosis

Background

Tuberculous pleural effusion (TPE) is one of the most common forms of extrapulmonary tuberculosis. Because most studies of TPE focused on the pleural space, little information regarding lung parenchyma is available. We therefore aimed to investigate immune responses in the lung parenchyma of TPE patients without pulmonary tuberculosis.

Methods

Patients with any evidence of pulmonary tuberculosis, either from radiologic or bacteriologic evaluation, were excluded. Bronchoalveolar lavage fluid (BALF) was collected from 10 newly diagnosed, untreated, HIV-negative TPE patients and 10 healthy controls. We analyzed T-lymphocyte subpopulations and measured 10 cytokines in BALF. Cytokine levels in BALF were standardised using urea.

Results

The concentrations of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), and the CD4+/CD8+ ratio of T-lymphocytes were significantly higher in TPE patients without pulmonary tuberculosis than in the controls. Of the cytokines measured in BALF, VEGF showed the highest concentration. No difference was observed in T-helper type 2 cytokines between the 2 groups.

Conclusion

There were significant immune responses and increases in IFN-γ, TNF-α, and VEGF in the lung parenchyma of TPE patients without pulmonary tuberculosis. This result suggests that TPE may induce a significant immune response in lung parenchyma.

Dynamics of adrenal steroids are related to variations in Th1 and Treg populations during Mycobacterium tuberculosis infection in HIV positive persons

Tuberculosis (TB) remains the most frequent cause of illness and death from an infectious agent, and its interaction with HIV has devastating effects. We determined plasma levels of dehydroepiandrosterone (DHEA), its circulating form DHEA-suphate (DHEA-s) and cortisol in different stages of M. tuberculosis infection, and explored their role on the Th1 and Treg populations during different scenarios of HIV-TB coinfection, including the immune reconstitution inflammatory syndrome (IRIS), a condition related to antiretroviral treatment. DHEA levels were diminished in HIV-TB and HIV-TB IRIS patients compared to healthy donors (HD), HIV+ individuals and HIV+ individuals with latent TB (HIV-LTB), whereas dehydroepiandrosterone sulfate (DHEA-s) levels were markedly diminished in HIV-TB IRIS individuals. HIV-TB and IRIS patients presented a cortisol/DHEA ratio significantly higher than HIV+, HIV-LTB and HD individuals. A positive correlation was observed between DHEA-s and CD4 count among HIV-TB individuals. Conversely, cortisol plasma level inversely correlated with CD4 count within HIV-TB individuals. M. tuberculosis-specific Th1 lymphocyte count was increased after culturing PBMC from HIV-TB individuals in presence of DHEA. We observed an inverse correlation between DHEA-s plasma level and Treg frequency in co-infected individuals, and CD4+FoxP3+ Treg frequency was increased in HIV-TB and IRIS patients compared to other groups. Strikingly, we observed a prominent CD4+CD25-FoxP3+ population across HIV-TB and HIV-TB IRIS patients, which frequency correlated with DHEA plasma level. Finally, DHEA treatment negatively regulated FoxP3 expression without altering Treg frequency in co-infected patients. These data suggest an enhancing role for DHEA in the immune response against M. tuberculosis during HIV-TB coinfection and IRIS.

Impact of Taenia solium neurocysticercosis upon endocrine status and its relation with immuno-inflammatory parameters

Neurocysticercosis (NC) is a parasitic disease caused by the infiltration of the larval stage of Taenia solium in the central nervous system. Clinical presentations are heterogeneous and particularly depend, on the age and gender of the host. We designed a clinical study to evaluate the hormonal changes associated with neurocysticercosis and the relationships between disease heterogeneity, endocrine and immunological status. A total of 50 patients and 22 healthy subjects were included. A precise clinical and radiological description of disease for each patient was recorded. A broad hormonal profile was assessed for each participant and, in a sub-group of patients, immunological features were also evaluated. Compared with controls, all patients had lower dehydroepiandrosterone (DHEA) concentration; male patients also had lower concentrations of 17β-estradiol and higher concentrations of luteinising hormone (LH). In the clinically severe patients, lower concentrations of progesterone and androstenedione were found in women. Higher concentrations of follicle stimulating hormone (FSH) and lower concentrations of testosterone were found in men when compared with the less clinically severe patients. Significant correlations were found between estradiol and IL-10 in male patients, and between dehydroepiandrosterone (DHEA) and IL-1β, and androstenedione and IL-17 in female patients. To our knowledge the present study constitutes the first demonstration that the presence of T. solium larvae in the central nervous system can modify the host environment by the induction of endocrine and immunological changes. These results provide a stimulating background to analyse the repercussions of these changes on the course of the disease and on patient reproductive health.

Immunological basis for the introduction of immunotherapy with Mycobacterium vaccae into the routine treatment of TB

An account is given of the immunological investigations carried out in Rosario (Argentina) to identify suitable methods for the assessment of the efficacy of immunotherapy for TB. Some of these were then applied to three small studies: one of a single injected dose of heat-killed, borate-buffered Mycobacterium vaccae administered early in treatment, another of three such doses administered at monthly intervals from the start of treatment, and the third of ten oral doses at frequent intervals throughout short-course chemotherapy. All three displayed better clearance of bacilli from the sputum, faster improvement in clinical symptoms, better radiological resolution of lesions and a return of most immunological parameters towards those of healthy persons. In principle, the immune change achieved is an increase in Th1 mechanisms, notably IL-2 and -12 with downregulation of the tissue damaging aspects of Th2. As an addition to chemotherapy for drug-susceptible or drug-resistant TB, with or without concomitant HIV infection, this immunotherapy offers a safe and effective improvement.

Potential for immunotherapy with heat-killed Mycobacterium vaccae in respiratory medicine

Immunotherapy with Mycobacterium vaccae has been shown to be beneficial as part of the treatment for a wide range of diseases. In the respiratory system, the late airway response in bronchial asthma is modified by a single dose and bronchial aspects of hayfever are reduced allowing a major reduction in the use of bronchial dilators. In studies of advanced adenocarcinoma of the lung survival is increased by an average of 4 months when up to five doses of M. vaccae are added to the course of chemotherapy. The quality of life of cancer patients receiving immunotherapy with M. vaccae is improved, even if survival is not increased. It is suggested that the mechanism of action of immunotherapy with heat-killed, borate-buffered M. vaccae is likely to be very similar in all these diseases for which human pulmonary tuberculosis provides a model. In this study, additional immunological data are reported from material stored from an earlier study of immunotherapy for pulmonary tuberculosis to help complete the information on the way that treatment with three monthly injections of heat-killed, borate-buffered M. vaccae (SRL172) may act.

RL, Actor JK. IL-6 mediates 11βHSD type 2 to effect progression of the mycobacterial cord factor trehalose 6,6'-dimycolate-induced granulomatous response

Granulomatous structures are highly dynamic during active mycobacterial infection, with accompanying responsive inflammation contributing to modulation of pathology throughout the course of disease. The heightened inflammatory response coinciding with initiation and maintenance of newly developing granulomatous structures must be limited to avoid excessive damage to bystander tissue. Modulating the cellular bioavailability of glucocorticoids by local regulation of 11βHSD enzymes within responding tissue and parenchyma would allow controlled inflammatory response during infection. Mycobacterial glycolipid trehalose 6,6'-dimycolate was used to induce strong pulmonary granulomatous inflammation immunopathology. Pulmonary corticosterone was significantly increased at days 3 and 5 after administration. An inverse relationship of 11βHSD1 and 11βHSD2 message correlated with pathology development. Immunohistochemical analysis also demonstrated that 11βHSD2 is expressed in proximity to granulomatous lesions. A role for pro-inflammatory IL-6 cytokine in regulation of converting enzymes to control the granulomatous response was confirmed using gene-disrupted IL-6-/- mice. A model is proposed linking IL-6 to endocrine-derived factors which allows modification of active corticosterone into inert 11-dehydrocorticosterone at the site of granuloma formation to limit excessive parenchymal damage.

Infection, immunity and the neuroendocrine response

The Central Nervous (CNS) and Immune Systems (IS) are the two major adaptive systems which respond rapidly to numerous challenges that are able to compromise health. The defensive response strictly linking innate to acquired immunity, works continuously to limit pathogen invasion and damage. The efficiency of the innate response is crucial for survival and for an optimum priming of acquired immunity. During infection, the immune response is modulated by an integrated neuro-immune network which potentiates innate immunity, controls potential harmful effects and also addresses metabolic and nutritional modifications supporting immune function. In the last decade much knowledge has been gained on the molecular signals that orchestrate this integrated adaptive response, with focus on the systemic mediators which have a crucial role in driving and controlling an efficient protective response. These mediators are also able to signal alterations and control pathway dysfunctions which may be involved in the persistence and/or overexpression of inflammation that may lead to tissue damage and to a negative metabolic impact, causing retarded growth. This review aims to describe some important signalling pathways which drive bidirectional communication between the Immune and Nervous Systems during infection. Particular emphasis is placed on pro-inflammatory cytokines, immunomodulator hormones such as Glucocorticoids (GCs), Growth hormone (GH), Insulin-like Growth Factor-1 (IGF-1), and Leptin, as well as nutritional factors such as Zinc (Zn). Finally, the review includes up-to-date information on this neuroimmune cross-talk in domestic animals. Data in domestic animal species are still limited, but there are several exciting areas of research, like the potential interaction pathways between mediators (i.e. cytokine-HPA regulation, IL-6-GCS-Zn, cytokines-GH/IGF-1, IL-6-GH-Leptin and thymus activity) that are or could be promising topics of future research in veterinary medicine.

Impaired immune responses in tuberculosis patients are related to weight loss that coexists with an immunoendocrine imbalance

The study's objective was to examine whether factors related to the host status may bear some relation with the profile of the immune response displayed by tuberculosis (TB) patients. The in vitro immune response (antigen-driven lymphoproliferation and cytokine production) and the presence of alcoholism or disease-related factors, like heart and respiratory rates, and weight loss (body mass index, BMI) were investigated in 31 males with active, untreated TB. Compared to 16 age-matched healthy males, TB patients presented depressed lymphoproliferation and increased IL-10 and TGF-beta production. Multivariate analysis indicated that most differences were no longer significant when controlling for the BMI. Immune and endocrine changes coexisting with weight loss, such as circulating levels of TNF-alpha, IFN-gamma, IL-6, cortisol, dehydroepiandrosterone and thyroid hormones, were also analyzed. While pairwise correlations between serum levels of IFN-gamma, T3 or T4 and BMI were not significant, BMI was negatively correlated with IL-6 levels (p < 0.025). In turn, levels of IL-6 correlated positively with cortisol concentrations (p <0.001). Stepwise regression analysis demonstrated that BMI was only associated with IL-6 (r = -0.423, R(2) = 0.18), with the difference remaining significant following adjustment for the other variables. As regards IL-6, BMI, cortisol and IFN-gamma could explain 74% of variability in IL-6 concentrations (R(2) = 0.74). No evidence for effect modification was shown when performing adjusted calculations. To conclude, the relation between weight loss and abnormal immune response of TB patients is partly associated with the immunoendocrine imbalance observed in parallel.