Peanut allergic subjects' peripheral blood mononuclear cell proliferative responses to crude peanut protein.
BACKGROUND
Peanut allergy is characterized by a high frequency of severe and occasionally fatal reactions.


OBJECTIVE
To determine if there are features of the in vitro cellular response that may account for the observed severity of peanut allergy.


METHODS
Skin-prick testing (SPT), RAST assay of serum peanut-specific and total IgE and mixed peripheral blood mononuclear cells (PBMC) proliferative responses to crude peanut protein were measured in 44 peanut allergics with varying severity of clinical reactions. PBMC responses of 13 non-peanut allergic controls (six atopic) were also studied.


RESULTS
Subjects' PBMCs proliferated more than controls', even without stimulation. Subjects' PBMC proliferative responses did not correlate with clinical severity, SPT weal size or peanut-specific IgE levels. Controls' PBMCs did not respond to peanut. There was no correlation between PBMC response and time since last reaction to peanut. Subjects' PBMCs responded more than controls, to mitogen as well as allergen. Proliferation increased with increasing concentration of peanut protein (P < 0.0001).


CONCLUSIONS
PBMCs of peanut allergics demonstrate a dose-dependent response to peanut which does not correlate with clinical severity, SPT reaction or levels of peanut specific IgE. The response is antigen-specific. Peanut protein is not mitogenic and is not acting as a superantigen. While there are non-specific differences in the PBMC responses of peanut allergic individuals compared with atopic and non-atopic controls, these differences do not explain the unique severity of peanut allergy.
Hourihane
J O
JO
Child Health, University of Southampton, Southampton General Hospital, UK.
Dean
T P
TP
Warner
J O
JO
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000917:Antibody Formation; D010367:Arachis / Q000009:adverse effects* / Q000737:chemistry* / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology / Q000494:pharmacology; D002455:Cell Division / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005512:Food Hypersensitivity / Q000097:blood / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D007782:Lactoglobulins / Q000276:immunology / Q000494:pharmacology; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000187:drug effects*; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D037121:Plant Lectins; D010940:Plant Proteins / Q000276:immunology* / Q000494:pharmacology*; D011852:Radioallergosorbent Test; D012882:Skin Tests
D017252:CD3 Complex; D007782:Lactoglobulins; D010835:Phytohemagglutinins; D037121:Plant Lectins; D010940:Plant Proteins; D007073:Immunoglobulin E