In this pilot study, perioperative administration of low-dose rhGM-CSF stimulated certain immune functions that are normally depressed after operation. The implications for the antitumour responses directly after operation and the formation of liver metastases are currently under investigation.

Irritant reactions to sodium lauryl sulfate were induced on the backs of 20 volunteers by means of patch test occlusion for 24 h. Different concentrations ranging from 0.25% to 2% were used, the lowest concentration being borderline irritant. The skin tests were read at 24, 48 and 72 h. Both the % of responding individuals and the intensity of the skin reactions were maximal at 48 h for all test concentrations. It is concluded that irritants may provoke inflammatory reactions which are not completely developed after 24 h, and are thus very similar to allergic patch test reactions.

No abstract

Epicutaneous tests with penicillins are important in the evaluation of penicillin allergy in patients who have shown a delayed urticarial or maculo-papular rash after the administration of penicillin derivatives. Of 23 patients who showed positive epicutaneous tests only 5 also showed immediate-type reactivity upon subsequent intractuaneous tests with the major determinant of penicillin. Moreover, patients with positive epicutaneous tests were evidently immunologically reactive on penicillins, since lymphocytes from 14 out of 17 patients showed increased DNA synthesis induced by penicillin G and ampicillin in vitro. The performance of epicutaneous tests with various penicillin derivatives is recommended as a first step in establishing penicillin allergy, because it is a safe method and because an extra group of sensitized patients is detected.

SUMMARYOral feeding of proteins causes peripheral T-cell tolerance, as revealed by reduced delayed-type hypersensitivity (DTH) reactivity after immunization. This type of tolerance can be due both to passive T-cell anergy and active immunosuppression. Using ovalbumin-fed mice we studied whether putatively immunostimulatory cytokines could break this state of mucosal tolerance. Cytokines were administered locally at the site of attempted sensitization. It was found that neither interleukin-2 (IL-2), interferon-g (IFN-g) nor granulocyte-macrophage colony-stimulating factor (GM-CSF) could restore the response to immunization. In contrast, local administration of IL-12 at the site of attempted immunization resulted in full recovery of DTH reactivity. The dichotomy between the two Th1 stimulatory cytokines IFN-g and IL-12 was also reflected by different effects on ovalbumin-specific antibody isotypes. Although both IFN-g and IL-12 downregulated serum IgG1-levels in tolerant mice, suggesting decreased ovalbumin-specific Th2 function, only local administration of IL-12 led to increased serum IgG2a levels. These results support the view that potentiation of Th1 effector function is critical for reversal of mucosal tolerance.