Stratum corneum antibodies detected by hemagglutination are not directed against keratin intermediate filaments

Abstract

Autoantibodies to stratum corneum (SC) occur in virtually all normal adult human sera. These antibodies may be directed against various antigens of the SC. They have been detected by indirect immunofluorescence, passive hemagglutination (HA), immune adherence, and most recently by enzyme immunoassay and immunoblot methods. The purpose of our study was to examine whether antibodies to SC antigens as detected by passive HA are similar to the keratin intermediate filament (KIF) reactive antibodies. SC antigen preparation was prepared from psoriatic scales by the trypsin-phenol-water (TPW) extraction method. KIFs were prepared by 8 M urea extraction of normal callus or psoriatic scales. The anti-SC antibody titers of normal human sera were determined by passive HA before and after absorption with TPW-SC antigen preparation and upon absorption with KIFs. Similarly, titers of anti-KIF antibodies were determined on absorbed and unabsorbed sera by immunoblot assay. The results of this study indicate that the absorption of the sera with KIFs did not affect the titer of antibodies to TPW-extractable SC antigens whereas the titer of KIF antibodies dropped. KIF-reactive antibodies, on the other hand, were not affected by absorption with TPW-SC antigen, whereas the latter absorbed out the corresponding reactive antibodies. These results indicate that antibodies directed against SC antigen are different from the KIF-reactive antibodies.

T Cell Stimulating Stratum Corneum Antigens: Characterization by Chromatography and Electrophoresis Indicates Limited Diversity

“…Normal serum antibodies that bind to components in aqueous extracts of human SC and in SC of frozen sections of human skin, have been known for many years (Binder et al, 1980;Dabski et al, 1985), but the epitopes involved and their pathogenic relevance are unclear. Although serum antibodies against keratin intermediate filaments have been described (Hintner et al, 1985), evidence indicates that SC antibodies are not directed against keratin intermediate filaments (Qutaishat et al, 1990). In addition, the similarity between the SC antigens recognized by serum antibodies and by T cells is not known.…”