José Artur Bogo Chies

Comparison of cytokine levels in depressed, manic and euthymic patients with bipolar disorder

BACKGROUND The neurobiology of bipolar disorder is not completely understood. Cytokines have received increasing attention as potential mediators of the interaction with immune, neuroendocrine system and specific pathways involved in mood, energy, and activity control. Previous reports have suggested the association of mania and bipolar depression with a proinflammatory state. However, they did not compare cytokine levels in all phases of bipolar disorder. METHODS Sixty-one bipolar patients were recruited for assessment of serum cytokine levels. Of these, 14 were in euthymic state, 23 and 24 were in manic and depressive episodes, respectively. A healthy comparison group included 25 healthy volunteers. Cytokines involved in Th1/Th2 balance, such as TNF-alpha, IL-2, IL-4, IL-6, IL-10, IFN-gamma, were examined by flow cytometry. RESULTS During mania, proinflammatory cytokines, IL-2, IL-4 and IL-6, were increased in comparison with healthy subjects. Patients in depressive episode showed only increased IL-6 levels. There were no significant differences in cytokine levels between patients in remission and healthy subjects, except for IL-4. Mood symptoms showed a positive correlation with IL-6 and IL-2. DISCUSSION These findings suggest that mania, and to a less extent, depression are associated with a proinflammatory state. These changes seem to be related to mood state, as changes in cytokine profile were more pronounced during acute episodes than in euthymia. This study provides further support to investigate the immune system as a target for future treatment development.

The role of mannose-binding lectin in systemic lupus erythematosus

Susceptibility to systemic lupus erythematosus (SLE) is associated with genetic, hormonal, immunological, and environmental factors. Many genes have been related with the appearance of SLE, including several loci that code different complement components and their receptors. Some genetic deficiencies of complement molecules are strongly associated with SLE, probably because these deficiencies could cause decreased clearance of apoptotic cell material. As a consequence of the apoptotic material accumulation, high levels of autoantigens can be presented inappropriately to the immune system in an inflammatory context, resulting in an imbalance on the mechanisms of immunological tolerance, immune system activation, and autoantibody production. Recent studies proposed a role to the mannose-binding lectin (MBL) in the SLE physiopathogenesis. This protein activates the complement system, and the presence of several polymorphisms at the promoter and coding regions of the MBL-2 gene determines alterations at the plasma levels of MBL. Some of these polymorphisms have been associated with SLE susceptibility, as well as with clinical and laboratory typical features of this disease, cardiovascular events, and infections. Besides, it has been described that the presence of anti-MBL autoantibodies in sera of SLE patients can influence MBL plasma levels and its functional activity.

Association of the HLA-G 14-bp insertion/deletion polymorphism with juvenile idiopathic arthritis and rheumatoid arthritis

We tested the possible association of the 14-bp polymorphism of the HLA-G gene in the course of two inflammatory diseases, rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA). Patients and controls were genotyped for the 14-bp polymorphism by polymerase chain reaction with specific primers for the exon 8 of the human leukocyte antigen (HLA)-G gene and the amplified fragment was visualized in a 6% polyacrylamide gel. A total of 106 JIA patients, 265 RA patients, 356 healthy adults and 85 healthy children were genotyped for the 14-bp polymorphism. Female JIA patients presented a higher frequency of the -14 bp allele when compared with female healthy children (0.743 and 0.500, corrected P=0.003), which reflected in the JIA group as a whole. This increased frequency of the -14-bp allele was observed in all JIA subtypes. In RA patients, no differences in allelic and genotypic frequencies were observed between patients and controls. No correlations were observed among genotype and disease severity or clinical manifestations. Our data suggest that the HLA-G -14 bp allele is probably a risk factor for JIA, mainly in females. Considering the differences observed in relation to gender, we suggest that hormonal differences can interfere with the development of JIA. Considering the RA patients, our data agree with results from the literature and highlight the differences in the etiology of RA and JIA.

Frequency of CCR5delta32 in Brazilian populations

A sample of 103 randomly chosen healthy individuals from Alegrete, RS, Brazil, was tested for the CCR5delta32 allele, which is known to influence susceptibility to HIV-1 infection. The CCR5delta32 allele was identified by PCR amplification using specific primers flanking the region of deletion, followed by electrophoresis on a 3% agarose gel. The data obtained were compared to those reported for other populations and interpreted in terms of Brazilian history. The individuals studied came from a highly admixed population. Most of them were identified as white (N = 59), while blacks and browns (mulattoes) were N = 13 and N = 31, respectively. The observed frequencies, considering the white, black and brown samples (6.8, 3.8, and 6.4%, respectively), suggest an important European parental contribution, even in populations identified as black and brown. However, in Brazil as a whole, this allele shows gradients indicating a relatively good correlation with the classification based on skin color and other physical traits, used here to define major Brazilian population groups.

Increased levels of interleukin-6, -8 and -10 are associated with fatal outcome following severe traumatic brain injury.

Abstract Background: Despite the involvement of cytokine production in neurotrauma, there is still controversy regarding cytokines levels and clinical outcome following severe traumatic brain injury (TBI). Objective: The present study was designed to investigate whether cytokine levels (of IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α) are associated with primary outcome (death or survival) after severe TBI. Methods: This prospective study enrolled 24 male patients, victims of severe TBI. Venous blood samples were taken in the Intensive Care Unit (ICU) (study entry), 24 and 48 hours later. Plasma cytokine levels were assayed by flow cytometry. Results: Severe TBI was associated with a 42% mortality rate. TBI patients had a significant increase in the levels of all cytokines measured, except for IL-1β, compared to controls. Statistically significant increases in the IL-10, -8 and -6 levels were observed in the non-survivors TBI patients compared to the survivors sub-group measured in the first sample (study entry) and in the subsequent sample (24 hours later). There were no significant differences in IL-1β, TNF-α and IL-12p70 levels between survivors and non-survivors in any time sampled. Conclusions: The findings indicate that increased IL-10, -8 and -6 levels may constitute an early predictor of unfavourable outcome in severe TBI patients.

5-Fluorouracil and its active metabolite FdUMP cause DNA damage in human SW620 colon adenocarcinoma cell line.

5‐Fluorouracil (5‐FU) is an antineoplasic drug widely used to treat cancer. Its cytotoxic effect has been principally ascribed to the misincorporation of fluoronucleotides into DNA and RNA during their synthesis, and the inhibition of thymidylate synthase (TS) by FdUMP (one of the 5‐FU active metabolites), which leads to nucleotide pool imbalance. In the present study, we compared the ability of 5‐FU and FdUMP to induce apoptosis and to influence the cell cycle progression in human colon SW620 adenocarcinoma cells in regards to their genotoxic and clastogenic activities. Our study demonstrates that 5‐FU induces SSB, DSB and apoptosis earlier than FdUMP. Interestingly, while both drugs are able to induce apoptosis, their effect on the cell cycle progression differed. Indeed, 5‐FU induces an arrest in G1/S while FdUMP causes an arrest in G2/M. Independently of the temporal difference in strand breaks and apoptosis induction, as well as the differential cell cycle modulation, both drugs presented similar clastogenic effects. The different pattern of cell cycle arrest suggests that the two drugs induce different types of primary DNA lesions that could lead to the activation of different checkpoints and recruit different DNA repair pathways. Copyright

High frequency of the CCR5delta32 variant among individuals from an admixed Brazilian population with sickle cell anemia

Homozygous sickle cell disease (SCD) has a wide spectrum of clinical manifestations. In Brazil, the main cause of death of individuals with SCD is recurrent infection. The CCR5delta32 allele, which confers relative resistance to macrophage-tropic HIV virus infection, probably has reached its frequency and world distribution due to other pathogens that target macrophage in European populations. In the present investigation a relatively higher prevalence (5.1%) of the CCR5delta32 allele was identified, by PCR amplification using specific primers, in 79 SCD patients when compared to healthy controls (1.3%) with the same ethnic background (Afro-Brazilians). Based on a hypothesis that considers SCD as a chronic inflammatory condition, and since the CCR5 chemokine receptor is involved in directing a Th1-type immune response, we suggest that a Th1/Th2 balance can influence the morbidity of SCD. If the presence of the null CCR5delta32 allele results in a reduction of the chronic inflammation state present in SCD patients, this could lead to differential survival of SCD individuals who are carriers of the CCR5delta32 allele. This differential survival could be due to the development of less severe infections and consequently reduced or less severe vaso-occlusive crises.

Reviewing the History of HIV-1: Spread of Subtype B in the Americas

The dispersal of HIV-1 subtype B (HIV-1B) is a reflection of the movement of human populations in response to social, political, and geographical issues. The initial dissemination of HIV-1B outside Africa seems to have included the passive involvement of human populations from the Caribbean in spreading the virus to the United States. However, the exact pathways taken during the establishment of the pandemic in the Americas remain unclear. Here, we propose a geographical scenario for the dissemination of HIV-1B in the Americas, based on phylogenetic and genetic statistical analyses of 313 available sequences of the pol gene from 27 countries. Maximum likelihood and Bayesian inference methods were used to explore the phylogenetic relationships between HIV-1B sequences, and molecular variance estimates were analyzed to infer the genetic structure of the viral population. We found that the initial dissemination and subsequent spread of subtype B in the Americas occurred via a single introduction event in the Caribbean around 1964 (1950–1967). Phylogenetic trees present evidence of several primary outbreaks in countries in South America, directly seeded by the Caribbean epidemic. Cuba is an exception insofar as its epidemic seems to have been introduced from South America. One clade comprising isolates from different countries emerged in the most-derived branches, reflecting the intense circulation of the virus throughout the American continents. Statistical analysis supports the genetic compartmentalization of the virus among the Americas, with a close relationship between the South American and Caribbean epidemics. These findings reflect the complex establishment of the HIV-1B pandemic and contribute to our understanding between the migration process of human populations and virus diffusion.

Immunophenotyping and T-cell proliferative capacity in a healthy aged population

The age-related decline of immunological functions is well established but it remains largely unknown which specific changes are related to disease. We analyzed peripheral blood lymphocytes of 42 healthy elderly as well as 24 healthy young subjects from southern Brazil. No differences in phytohemagglutinin-induced proliferation and CD4:CD8 ratio were found between the subjects. However, CD4 expression (considering mean fluorescence intensity) was found up regulated in elderly subjects. No changes in activation molecules CD25, CD28, CD69 and CD95 were observed. A reduced proportion of naive (CD45RA+) T cells was found in the elderly compared to young subjects. No changes in adhesion molecule expression (CD11c and CD31) were observed. However, the frequencies of CD49d-positive cells, as well as expression of CD62L, were increased in the eldery subjects. We further described two subgroups of eldery subjects with an immunological risk profile defined by lower CD4:CD8 ratio and reduced proliferative response to mitogens. These data suggest that healthy aging is associated with intact T-cell proliferation and some compensatory immunophenotypical changes.

Distress conditions during pregnancy may lead to pre-eclampsia by increasing cortisol levels and altering lymphocyte sensitivity to glucocorticoids

Psychological stress may affect up to 18% of all pregnant women, altering the function of both neuroendocrine and immune systems. Distress conditions may directly change the hypothalamic-pituitary-adrenal (HPA) axis, leading to increased cortisol levels and associated changes in cellular immunity. Psychological events such as high stress levels, anxiety or depression may directly or indirectly affect pregnancy and may thus lead to pre-eclampsia (PE). Here, we suggest that distress conditions during pregnancy may lead the development of PE by enhancing in vivo cortisol levels. High cortisol levels are associated with hypertension and endothelial dysfunction, features often observed in patients with PE. Lymphocytes from patients with high cortisol levels may have a reduced sensitivity to the synthetic glucocorticoid dexamethasone (DEX). Stress-related steroid resistance may disrupt the HPA axis, leading to post-natal detrimental effects such as increased allostatic load, increased pro-inflammatory cytokine levels and even depression in the offspring.