Previously we established that a cocoa-enriched diet in young rats reduces specific antibody production and the T helper (Th) lymphocyte proportion in lymphoid tissues. The aim of the present study was to ascertain the modulatory ability of a cocoa flavonoid-enriched diet on collagen-induced arthritis (CIA), which is mediated by anti-collagen autoantibody response and Th lymphocyte activation. Female Louvain (LOU) rats were fed with a cocoa-enriched diet, beginning 2 weeks before CIA induction. Hind-paw swelling and serum cytokine and anti-collagen antibody concentrations were determined. Anti-collagen antibody-secreting cell counts and lymphocyte subset proportions were established in inguinal lymph nodes (ILN). Reactive oxygen species (ROS), nitric oxide (NO) and TNFα produced by peritoneal macrophages were determined. Although arthritic cocoa-fed rats showed a similar hind-paw swelling time course as the arthritic animals fed a standard diet, the cocoa intake was able to decrease specific IgG2a, IgG2b and IgG2c titres. Moreover, cocoa intake in CIA rats reduced ROS production, TNFα and NO release from peritoneal macrophages, and decreased the Th:cytotoxic T cell ratio in ILN. In conclusion, a cocoa flavonoid-enriched diet in LOU rats with CIA produced no effect on hind-paw swelling but was able to modulate the specific antibody response and also the Th lymphocyte proportion, as well as the synthesis of pro-inflammatory mediators from peritoneal macrophages. Therefore, a cocoa-enriched diet could be a good adjuvant therapy in disorders with oxidative stress or autoimmune pathogenesis.

The aim of this article is to evaluate the role of allergy in the pathogenesis of Ménière’s disease by means of cytokine profiles, allergic parameters and lymphocyte subgroups. A total of 46 patients aged between 26–68 years diagnosed with Ménière’s disease between 1993–2002 were recruited to this study. The control group consisted of 46 healthy volunteers who were from the same age group, living in the same region and possessing similar socioeconomic indicators. Lymphocyte subgroups were measured from the peripheral blood by employing Becton Dickinson (BD) monoclonal CD4, CD8, CD23 antibodies. IFN-γ, IL4, total IgE levels, and specific IgE levels pertaining to tree, fungus, fruit, egg-white, cow’s milk, wheat flour, corn flour, beef, and rice allergens, in all seasons, were measured and compared in the patient and control groups.

In patient serum samples there were positive correlations between CD23 and IgE, CD8 and IgE, CD47sol;CD8 and IgE, and CD23 and CD8 (p <0.01). There were negative correlations between IL-4 and IFN-γ , IFN-γ and IgE, and a positive correlation between IL-4 and IgE. Total IgE levels were above the normal values in 19/46 (41.3 per cent) of the patient group, but the ratio was nine out of 46 (19.5 per cent) in the control group. A history of allergy was found in 31/46 (67.3 per cent) when the patients were questioned. The ratio of a history of allergy was 16/46 (34.7 per cent) in the control group. When specific IgE levels were evaluated the ratio of patients with all the panels negative was eight out of 46 (17.9 per cent), but it was 31/46 (67.3 per cent) in the control group.

This study found that the prevalence of allergy was higher in patients with Ménière’s disease than in the control group. Thus the authors suggest that allergy should be taken into account when patients with this disease are treated.

As a result of evidence documenting harmful effects of Zn supplementation on immune function and Cu status, thirty-eight men were recruited onto a Zn supplementation trial. The aim was to examine the effects of chronic Zn supplementation on circulating levels of peripheral blood leucocytes and lymphocyte subsets. Subjects (n 19) took 30 mg Zn/d for 14 weeks followed by 3 mg Cu/d for 8 weeks to counteract adverse effects, if any, of Zn supplementation on immune status resulting from lowered Cu status. A control group (n 19) took placebo supplements for the duration of the trial. Dietary intakes of Zn approximated 10 mg/d. Blood samples, taken throughout the trial, were assessed for full blood profiles and flow cytometric analyses of lymphocyte subsets. Putative indices of Cu status were also examined. Results indicate that there was no effect of Zn supplementation on circulating levels of peripheral blood leucocytes or on lymphocyte subsets. Cu status was also unaltered. Independent of supplement, there appeared to be seasonal variations in selected lymphocyte subsets in both placebo and supplemented groups. Alterations in circulating levels of B cells (cluster of differentiation (CD) 19), memory T cells (CD45RO) and expression of the intracellular adhesion molecule-1 (CD54) on T cells were observed. Findings indicated no adverse effects of Zn supplementation on immune status or Cu status and support the US upper level of Zn tolerance of 40 mg/d. The seasonal variations observed in lymphocyte subsets in the group as a whole could have implications for seasonal variability in the incidence of infectious diseases.