fibrinopeptide-a and Hypersensitivity

The levels of histamine, fibrinopeptide A (FPA), and IgG were determined in chamber fluids overlying sites of antigen versus buffer incubation for up to 7 hours in seven atopic and four antigen-nonreactive subjects. Significant increases in histamine were observed at antigen versus buffer sites in the atopic subjects throughout the 7-hour period. FPA and IgG levels were higher in antigen than in buffer sites from 0 to 5 hours in the atopic subjects. Furthermore, FPA levels correlated with the magnitude of induration at 6 hours after antigen injection in atopic subjects. There were no differences in the levels of histamine, FPA, or IgG at antigen versus buffer sites in the skin test-negative subjects. We suggest that the combination of vascular leakage of proteins, induced by vasoactive mediator release, and activation of these proteins during ongoing cutaneous reactions is responsible for fibrin formation that contributes to the pathophysiology of late-phase allergic responses in the skin.

Topics: Adult; Blood Coagulation; Female; Fibrinopeptide A; Histamine; Humans; Hypersensitivity; Hypersensitivity, Immediate; Immunoglobulin G; Male; Skin; Skin Tests; Skin Window Technique; Time Factors

We detected a human humoral peptide that deglycosylates mouse antibody IgE, and found that this peptide had the amino acid sequence ADSGEGDFLAEGGGV. The peptide synthesized according to the sequence also deglycosylated the antibody IgE. The deglycosylated IgE did not induce mouse systemic anaphylaxis. Human fibrinopeptide A has the amino acid sequence indicated above, and a polypeptide extracted from human urine showed an antiallergic effect on humans and mice, which strongly suggests that fibrinopeptide A mediates allergic reaction via antibody IgE-deglycosylation, and is excreted as a polypeptide in urine.

Topics: Acute-Phase Reaction; Adult; Amino Acid Sequence; Animals; Drug Hypersensitivity; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Female; Fibrinopeptide A; Glycosylation; Glycosyltransferases; Humans; Hypersensitivity; Immune Sera; Immunoglobulin E; Injections, Intraperitoneal; Male; Mice; Mice, Inbred Strains; Molecular Sequence Data; Ovalbumin; Peptide Fragments; Structure-Activity Relationship

In a 32-year-old woman and a 40-year-old man with cutaneous vasculitis, etiological allergic responses to foods and airborne allergens were found. During provocation tests, observations were made on blood levels of fibrinopeptide A(FPA) and coagulation factors, fibrinogen degradation products (FDP) and serum complement components. Skin biopsies were taken for microscopic and immunofluorescence analysis. In case 1, anaphylactoid allergy to milk and reaginic and anaphylactoid hypersensitivity to grass pollens were found. Dermal provocations with grass pollens gave arthralgia, hematomas, serum C3 fluctuation, factor VII reduction and fibrinolysis. During peroral milk challenge, transient increases in FPA and FDP levels were observed before symptoms appeared. In case 2, anaphylactoid hypersensitivity responses to bacteria, animal danders, foods and pollens were found. Two inhalations with sheep-wool extract resulted in a typical skin eruption. The first also gave an early reduction of C3 and then FPA liberation. Nasal birch-pollen test gave an increase of FPA in the latent period and then typical nodules. At least no low molecular weight FDP were detected during provocations. In patients with vasculitis reactions to exogenous allergens, FPA and FDP estimations after provocations may discriminate harmful from innocuous allergens and reveal individual response patterns in coagulation and fibrinolysis systems.

Topics: Adult; Allergens; Blood Coagulation; Complement C3; Complement C4; Complement System Proteins; Female; Fibrin Fibrinogen Degradation Products; Fibrinogen; Fibrinolysis; Fibrinopeptide A; Humans; Hypersensitivity; Male; Middle Aged; Skin; Vascular Diseases