The purpose of this study was to characterize the association between anti-prothrombin antibodies and the lupus anticoagulant (LA) in order to elucidate the antigenic site of the LA. Plasma from 8 patients with the LA had evidence of anti-prothrombin antibodies on prothrombin crossed immunoelectrophoresis as characterized by material moving slower in the first dimension of electrophoresis than normal prothrombin, i.e., a trailing shoulder. Four of 5 LA patients with a prolonged prothrombin time demonstrated the most pronounced evidence of anti-prothrombin antibodies. All patients were shown to have an essentially normal level of prothrombin antigen. Using an enzyme-linked immunosorbent assay (ELISA), six of 8 LA patients tested positive for anticardiolipin antibodies (aCL) of the IgG isotype while 7 of 8 LA patients tested positive for antiphosphatidylserine antibodies (aPS) of the IgG isotype.An anti-human Factor II (prothrombin) ELISA was developed to confirm the presence of anti-Factor II (aFII) activity in LA patients. Seven of 8 LA patients were positive for aFII activity. A strong parallel existed between the presence of aPS activity, anti-human Factor II activity, and the LA, i.e., 7 of 8 LA plasmas were aPS (+)/aFII (+). An antibovine Factor II ELISA was developed to determine if the aFII activity associated with LA patients is speciesspecific. Three of 5 LA patients positive for anti-human Factor II activity were also shown to be positive for antibovine Factor II activity. Antibodies with specificity for human prothrombin were purified from LA plasmas using a prothrombin affinity column. Three of 8 LA patient eluates were shown to be positive for aPS (IgG) while none were positive for aCL (IgG or IgM) or human aFII activity. Affinity-purified eluates were assayed for LA activity using the dilute Russell viper venom time (dRVVT). None of the LA patient eluates were shown to prolong the dRVVT when present with normal plasma in concentrations up to 100 micrograms/mL. / Department of Chemistry
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/184342 |
| Date | January 1992 |
| Creators | Murphy, Timothy Lynn |
| Contributors | Ball State University. Dept. of Chemistry., Triplett, Douglas A. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | vii, 105 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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