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Objective: To determine the polymorphism at position 247 of the beta(2)-glycoprotein I (beta(2)GPI) gene in Mexican patients with antiphospholipid syndrome (APS) and to compare these data in patients with or without antibodies to beta(2)GPI and with the clinical manifestations of APS., Methods: We studied 39 patients with primary APS and compared them with 106 clinically healthy subjects. Polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism. The presence of "true" anticardiolipin (aCL) antibodies, beta(2)GPI-dependent aCL antibodies (IgG and IgM), and phospholipid-free anti-beta(2)GPI antibodies (IgG isotype) were detected by enzyme-linked immunosorbent assay (ELISA) utilizing nonirradiated ELISA plates. Clinical manifestations associated with antiphospholipid antibodies were also evaluated., Results: We found no significant differences in the genotype expression between the control group and the primary APS patients (13% with VV, 52% with VL, and 35% with LL versus 23% with VV, 51% with VL, and 26% with LL, respectively). In contrast, anti-beta(2)GPI-positive patients had significantly higher frequencies of the VV genotype and V allele expression than the control subjects and the anti-beta(2)GPI-negative patients. These genotype and allele frequencies were also significantly higher in patients with arterial thrombosis than in patients without it. Anti-beta(2)GPI-negative patients without arterial thrombosis did not express the VV genotype. We found no differences in the Val/Leu(247) polymorphism of the beta(2)GPI gene in primary APS patients with or without "true" aCL antibodies or in primary APS patients with or without beta(2)GPI-dependent aCL antibodies., Conclusion: Our results suggest that the VV genotype at position 247 of the beta(2)GPI gene may play a role in the generation of anti-beta(2)GPI antibodies and perhaps in the expression of arterial thrombosis in primary APS.

Connective tissue activating peptide-V (CTAP-V) is a single-chain, mesenchymal cell-derived anionic protein with large and small molecular forms (Mr of 28,000 and 16,000, respectively), as defined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteins have similar specific activities with respect to stimulation of hyaluronic acid and DNA formation in human synovial fibroblast cultures. S-carboxymethylation or removal of sialic acid residues did not modify CTAP-V biologic activity. Rabbit antibodies raised separately against each of the purified CTAP-V proteins reacted, on immunodiffusion and on Western blot, with each antigen and neutralized mitogenic activity. The amino-terminal amino acid sequence of the CTAP-V proteins, determined by 2 laboratories, confirmed their structural similarities. The amino-terminal sequence through 37 residues was demonstrated for the smaller protein. The first 10 residues of CTAP-V (28 kd) were identical to the N-terminal decapeptide of CTAP-V (16 kd). The C-terminal sequence, determined by carboxypeptidase Y digestion, was the same for both CTAP-V molecular species. The 2 CTAP-V peptides had similar amino acid compositions, whether residues were expressed as a percent of the total or were normalized to mannose. Reduction of native CTAP-V protein released sulfhydryl groups in a protein:disulfide ratio of 1:2; this suggests that CTAP-V contains 2 intramolecular disulfide bonds. Clearly, CTAP-V is a glycoprotein. The carbohydrate content of CTAP-V (16 kd) and CTAP-V (28 kd) is 27% and 25%, respectively. CTAP-V may have significance in relation to autocrine mechanisms for growth regulation of connective tissue cells and other cell types.

We previously identified, in normal urine, a growth factor that stimulated monolayer cultures of human synovial, cartilage, and dermal fibroblasts to synthesize incremental amounts of hyaluronic acid, proteoglycans, and DNA. An isolation procedure guided by bioassays and immunologic methods disclosed 2 anionic bioactive polypeptides with Mr of 28,000 and 16,000, respectively, as judged by single bands with sodium dodecyl sulfate-polyacrylamide gel electrophoresis in reduced and nonreduced samples. Rabbit antibodies raised against each purified protein were shown to react, on immunodiffusion and Western blot, with both antigens. Immunohistochemical and immunobinding studies detected the protein in normal human synovial, dermal, and cartilage fibroblasts and in human saphenous vein endothelial cells. The mesenchymal cell-derived growth factor is now designated connective tissue activating peptide-V (CTAP-V). Monospecific polyclonal anti-CTAP-V antibodies were used in a radial immunodiffusion assay for quantitative determination of the antigen in biologic fluids. In normal human plasma the concentration of CTAP-V was below the limit of detection. The CTAP-V concentration in normal urine was 4.5 +/- 2.0 micrograms/ml, calculated from measurements of 5-18-fold concentrated samples. Joint fluid from patients with rheumatic diseases and normal renal function had CTAP-V levels similar to those found in plasma; 2-15-fold increases were detected in plasma and joint fluid of patients with chronic renal failure. Immunodiffusion or dot-blot analysis revealed a CTAP-V-like material in the plasma or serum of 10 mammalian species. It was not detectable in 2 avian species.