title: Evaluation of lupus anticoagulants: antiphospholipid antibodies, endothelium associated immunoglobulin, endothelial prostacyclin secretion, and antigenic protein S levels.
abstract: Plasma samples from nineteen patients with well characterized lupus anticoagulants (LA) were evaluated using a series of test systems. An ELISA was used to determine if the plasmas contained antiphospholipid antibodies (APA); fifteen of nineteen LA plasmas contained APA, with five exhibiting IgG only, two exhibiting IgM, and eight plasmas containing both IgG and IgM. Anti-phosphatidyl serine (PS) was the predominant IgG specificity and all IgM APA-containing plasmas reacted with phosphatidyl inositol (PI). An ELISA was developed to determine if LA plasmas contained immunoglobulin which would associate with cultured human umbilical cord vein-derived endothelial cells (HUV); ten of nineteen plasmas contained endothelium associated immunoglobulin (EAI). There was significant concordance between the occurrence of EAI and IgM anti-PI. The occurrence of EAI or APA, either singly or in combination, did not correlate with a past history of thrombosis. Patient plasmas were incubated with HUV and examined for effects on HUV prostacyclin (PGI2) secretion; six plasmas significantly stimulated PGI2 secretion and one plasma was inhibitory. Finally, plasma levels of free and total antigenic protein S were determined by EID. Five plasmas contained significantly reduced levels of free antigenic protein S, and total antigenic protein S was reduced in ten plasmas. Patient histories were examined for evidence of thrombotic episodes; six patients had a history of either arterial or venous thrombosis, with five of these six patients having drug-induced LA. Thus, unlike previous studies, drug-induced LA were associated with thrombosis.
authors.affiliation: Muncie Center for Medical Education, Indiana University School of Medicine.
authors.forename: T S
authors.initials: TS
authors.lastname: Walker
authors.forename: D A
authors.initials: DA
authors.lastname: Triplett
authors.forename: N
authors.initials: N
authors.lastname: Javed
authors.forename: K
authors.initials: K
authors.lastname: Musgrave
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000032:analysis*; D001779:Blood Coagulation Factors / Q000032:analysis / Q000276:immunology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D011464:Epoprostenol / Q000378:metabolism; D005260:Female; D006023:Glycoproteins / Q000032:analysis / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis*; D016682:Lupus Coagulation Inhibitor; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000276:immunology*; D017293:Protein S
chemical_list: D001323:Autoantibodies; D001779:Blood Coagulation Factors; D006023:Glycoproteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D016682:Lupus Coagulation Inhibitor; D010743:Phospholipids; D017293:Protein S; D011464:Epoprostenol