Specific humoral immune responses in 12 cases of food sensitization to sesame seed.

BACKGROUND: Hypersensitivity to sesame seeds is becoming increasingly frequent, probably owing to the larger use of this compound in international food. OBJECTIVES: This study investigated serum responses of 12 sesame sensitized patients (seven with food allergy, five with food sensitization), to a sesame protein extract, and attempted at identifying sesame major antigens. METHODS: Sesame protein extracts were prepared from black, white and brown sesame seeds. Electrophoretic analysis showed similar protein patterns in the three extracts, and proper preservation of the proteins integrity. The brown sesame extract was used to set-up an ELISA assay and measure serum levels of antisesame IgG, IgA, IgM and IgE in 12 samples from sesame-sensitized individuals and six controls. It also allowed to perform western blot analyses in order to investigate the molecular weight of sesame proteins recognized by IgG, IgA and IgE. RESULTS: Nineteen protein bands were observed upon polyacrylamide gel electrophoresis of the sesame protein extracts. Using this whole extract in ELISA, significant antisesame IgG, IgA and IgE-responses were observed in the serum of sensitized individuals, different from the lower signals obtained with control samples. Western blot analysis demonstrated highly polymorphic IgG and IgA responses and a more restricted IgE response pattern, suggesting that two proteins, respectively, 14 kDa and 25 kDa are mostly involved in sesame IgE-dependent hypersensitivity, the 25 kDa band presenting several characteristics of a major allergen. CONCLUSIONS: This study reports novel information on the possible involvement of a 25 kDa sesame protein in IgE-dependent hypersensitivity to sesame seeds.

Comparative assessment of phospholipid-binding antibodies indicates limited overlapping.

The implication of autoantibodies with anticoagulant and/or so-called antiphospholipid activities, under clinical circumstances with vascular obliteration, has led to the development of various types of tests allowing their detection. The most used tests involve investigation of the presence of an anticoagulant effect and of anticardiolipin IgG. It has also been proposed that the reactivity of patient samples toward other phospholipids or proteins be tested, but it remains difficult to appreciate which tests are redundant or complementary. Here we investigated whether the dissociation or association of anticoagulant and anticardiolipin correlated with specific ELISA reactivity to five other phospholipids: phosphatidylserine, phosphatidylinositol, phosphatidic acid, phosphatidylcholine, and phosphatidylethanolamine. The study was performed with 70 samples, evenly partitioned as positive for either anticardiolipin antibodies or anticoagulant effect, or both. Our data clearly confirm that cardiolipin reactivity is an individual entity, likely to be complementary to other assays. Neither anticardiolipin nor anticoagulant levels correlated with assays investigating antibody levels toward the five other phospholipids, although higher mean levels were noted when both lupus anticoagulant and anticardiolipin antibodies are present. Individual patterns were evidenced in all groups. These data support the interest of current and further studies exploring the clinical relevance of individual reactivities to phospholipids.

Peripheral blood T-lymphocyte subsets in the follow-up of psoriasis patients under PUVA therapy.

Peripheral lymphocyte subsets were analyzed before and after treatment in 22 patients with psoriasis. All patients had PUVA therapy for at least 1 month. Eight of them were assessed after 1 and 2 months of therapy. Abnormal partitions of T-cell subsets were observed in 10 patients before treatment. Positive dermatological results were concomitant with a significant decrease of the CD8 subset. Variations of the Leu7+ subset were observed as well. These data support current theories on the effect of UV light on the immune system and provide a possible useful way to monitor psoriatic patients receiving PUVA therapy.