High positive frequency of antibodies to metallothionein and heat shock protein 70 in sera of patients with metal allergy
Two principal types of stress protein, heat shock proteins (hsps) and metallothionein (MT), are inducedin cells responding to a variety of stresses. They play an important role in protecting cells from thesestresses. However, many reports indicate that antibodies to hsps are present in human serum and areassociated with several autoimmunity diseases. Metals, which are commonly allergenic to humans,induce both MT and hsp70 (one of the hsps family). Until now, there has been no report of any antibodyto MT in human serum. In the present study, serum samples from healthy controls (Group I), andpatients suffering from atopic dermatitis without (Group II) or with (Group III) metal allergy, weremeasured for antibodies to MT and hsp70, using an enzyme-linked immunosorbent assay (ELISA).Metal allergy was confirmed by patch testing. We first found that antibody to MT exists in human serum.We also found a high positive frequency of antibody to MT (51·3%) and to hsp70 (43·6%) in the seraof Group III, compared to those of Group I (3·8% and 5·1%) or Group II (6·4% and 5·1%). Furthermore,there was a strong positive correlation between antibody to MT and antibody to hsp70 in GroupIII (P = 0·0013), but not in Group I and Group II. Our results indicate that antibody to MT exists inhuman serum, as do antibodies to hsps, and suggest