Elevated serum levels of proinflammatory cytokines potentially correlate with depression and anxiety in colorectal cancer patients in different stages of the antitumor therapy

Depression and anxiety, the most important psychological disorders in cancer patients, have now been considered as psychoneuroimmunological disorders, in which peripheral immune activation, through the release of proinflammatory cytokines, is implicated in the variety of behavioral, neuroendocrine and neurochemical alterations associated with these disorders. Along with the tumor itself, cancer treatment can also contribute to exacerbate the production of proinflammatory cytokines. This study aimed to investigate whether proinflammatory cytokine levels are related to depression and anxiety in CRC patients in different stages of the antitumor therapy We evaluated 60 patients in three stages of antitumor therapy (Pre-chemotherapy, Under-chemotherapy and Post-chemotherapy, n=20 in each group) and 20 healthy volunteers by the Hospital Anxiety and Depression Scale (HADS). Serum levels of cytokines were measured by CBA. Depression and/or anxiety were found at clinically relevant levels in CRC patients during all antitumor therapy. Patients in pre-chemotherapy group exhibited the highest concentrations of pro-inflammatory cytokines and the lowest levels of IL-10. In latter stages of treatment, cytokines reached levels similar to the control group. Correlation analysis between HADS score and cytokine serum levels revealed positive associations of anxiety and/or depression with IL-1β, IL-6, IL-8, and TNF-α, and a negative correlation with IL-10, suggesting that cytokines are involved in the pathophysiology of these psychological disorders in CRC patients. A better understanding of the molecular mechanisms involved in these psychological disorders will allow the design of new therapeutic strategies to assist in alleviating such symptoms in cancer patients.

Antibody and cytokine responses to house dust mite allergens and Toxoplasma gondii antigens in atopic and non-atopic Brazilian subjects

According to hygiene hypothesis, a lower exposure to infection is associated with increased prevalence of allergic diseases. This study aimed to investigate the association between atopy and Toxoplasma gondii (Tg) infection by analyzing the antibody and cytokine responses to house dust mite allergens and T. gondii antigens in Brazilian subjects. A total of 275 individuals were assessed and divided into atopics (n=129) and non-atopics (n=146) based on markers of allergy (positive skin prick test and ELISA-IgE to mite allergens) or Tg-seropositive (n=116) and Tg-seronegative (n=159) groups according to infection markers (positive ELISA-IgG to T. gondii). Tg-seropositive individuals presented lower allergenic sensitization (37%) to mite allergens than Tg-seronegative subjects (54%). A significant association was found between atopy and negative serology to T. gondii (OR: 2.0; 95% CI: 1.23-3.26; P<0.05). Proliferative responses and cytokine production after antigenic stimulation showed predominant synthesis of Th1-cytokines as IFN-gamma in Tg-seropositive patients, whether atopics or non-atopics. Conversely, Th2-cytokines as IL-5 prevailed in atopics compared to non-atopics, regardless the seropositivity to T. gondii. Levels of IL-10, IL-13, IL-17, and TGF-beta were not able to discriminate the groups. Hence, a negative association between atopy and infection by T. gondii was demonstrated for the first time in Brazilian subjects, focusing on the antibody and cytokine responses and indicating that the immunomodulation induced by the parasite may play a protective role in the development of allergic diseases.

Ultrastructural features of alveolar cells in experimental hypersensitivity pneumonitis

An experimental model of hypersensitivity pneumonitis in rats was used to analyze ultrastructural changes in cellular elements of the epithelium and alveolar lumen, in an attempt to correlate the immunological mechanisms responsible for these pulmonary lesions. Semifine and ultrafine sections of pulmonary tissue of immunized and intratracheally challenged rats were analyzed and compared with their respective controls. A thickening of the alveolar walls and an increase in the number of macrophages and type II pneumocytes were observed in the semifine sections. The ultrastructural examination revealed appreciable changes in morphology, size and location of both types of cells. The membranes of the macrophages showed evident alterations and the type II pneumocytes, an increase in size and number of cytoplasmic inclusions corresponding to surfactant. The cellular changes observed are consistent with phenomena of cellular activation, which can be attributed to the release of soluble mediators by T lymphocytes. The important delayed hypersensitivity phenomena based on the morphology of pulmonary lesions in this model contribute data to the pathogenic interpretation of hypersensitivity alveolitis.