Aim: To estimate incidence rate of Leiden mutation in factor V gene, prothrombin gene mutation responsible for replacement of G for A in position 20210 (G20210A) of its 3'-end noncoding part in patients with systemic lupus erytheamtosus (SLE) and antiphospholipid syndrome (APS) and their relationships with antiphospholipid antibodies (aPL): lupus anticoagulant (LA) and anticardiolipin antibodies (aCL).
Materials and methods: The trial included 33 patients (2 males and 31 females) aged 20-62 years (mean age 32.7 +/- 9.8 years). 29 patients suffered from SLE, 17 of them had also APS (criteria by G. R. V Hudhes). 3 patients had primary APS, 1 female had hemorrhagic vasculitis. IgG and IgM-aCL were detected by enzyme immunoassay. In revealing mutation, DNA was used isolated from peripheral blood by standard methods based on polymerase chain reaction (PCR). Primary screening of Leiden mutation was made according to Bertina et al. with Mnl I restrictase. The mutation was confirmed by an original technique with allele-specific primers. G20210A mutation in the prothrombin gene was determined with restrictase Taq I after introduction of artificial restriction site in PCR product. The patients were divided into 2 groups. Group 1 incorporated 12 patients with SLE without APS. Group 2--21 patients with APS (17 with SLE + APS, 3 with primary APS and 1 with hemorrhagic vasculitis).
Results: Patients of group 1 had neither thrombotic complications nor Leiden mutation. Two patients of group 2 had heterozygous Leiden mutation. Both females were aPL-positive and had previously recurrent thrombophlebitis. One of them had also recurrent disorders of cerebral circulation. None of the examinees had any G20210A mutations in the prothrombin gene.
Conclusion: Detection of genetic defects in APS provide arguments in the dispute about the necessity, duration and choice of anticoagulant therapy. If patients with APL syndrome appeared to have besides aPL also genetic defects in coagulation, this will enable identification of patients at high risk of thrombosis which need permanent administration of anticoagulants among which only low-molecular ones or glycosaminoglycanes are indicated. Mutation in gene of factor V is absolute contraindication to phenilin and quamarines.