Lymphocyte response to phytohemagglutinin in atopic dermatitis

Abstract

Studies of patients with atopic dermatitis (AD) have demonstrated several clinical and laboratory indications of immunity defects, but with frequently contradictory results. We have recently shown that many patients with negative cutaneous delayed type hypersensitivity to candidin and streptokinase-streptodornase may have normal in vitro lymphocyte transformation to the same antigens. We hypothesized that this represents recovery of immunocompetent cells when they are isolated in vitro. This report describes phytohemagglutinin-induced transformation of lymphocytes immediately after isolation and after four days in culture (precultured). Responses of lymphocytes from patients with AD were initially subnormal, but increased to normal levels after the preculture period. Our results suggest that defective immune function in AD is not due to a permanent intrinsic lymphocyte defect, but is more likely due to factors associated with disease activity and severity.

Responsiveness of Peripheral Blood Mononuclear Cells from Normal and Atopic Donors to Microbial Superantigens

“…Leishmania major, tuberculoid leprosy, helminth infec tions, HIV, Toxoplasma or listerosis [32], It has been known for many years that T cells from patients with AD respond with a reduced [3H]thymidine incorporation to mitrogens, e.g. phytohemagglutinin or concanavalin [33]. Concomi tant to these findings, stimulation of purified T-cell suspen sions containing few monocytes with the potent T-cell sti muli enterotoxin B and A resulted in a significantly de creased T-cell proliferation in patients with AD compared to cells from normal donors.…”

CD4+ Memory T Cells in Peripheral Blood Are Not Decreased in Patients with Atopic Dermatitis

“…During severe exacerbations of AD blood lympho cytes show a reduced response to nonspecific mitogens such as phytohemagglutinin which reverts to normal lev els during remission [13]. Peripheral blood CD8+ sup pressor T cells may be reduced up to 25%, a finding which has been considered to be responsible for elevated IgE serum levels [1].…”