Aim: To study prevalence of mutation C677T in gene 5.10-MTHFR in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) as well as in persons free of symptoms of systemic diseases of the connective tissue.
Material and methods: 85 patients participating in the study were divided into three groups: those with SLE (n = 17), with SLE + APS (n = 42), with primary APS (n = 26). The control group consisted of 30 persons without SLE or APS. 55% of the examinees had thrombotic complications of different location. The diagnosis of the mutation was made using DNA isolated from the peripheral blood with standard methods and polymerase chain reaction. Allele (homozygous or heterozygous) condition of the mutation was confirmed by means of allele-specific primers.
Results: Mutation C677T in MTHFR gene was found in 40 of 85 patients (47%); 11(27.5%) had a homozygous variant, 29(72.5%)--heterozygous. C677T mutation occurred in 5 of 17 SLE patients (29%), it was in all the cases heterozygous. In primary and secondary APS mutation was detected in 51.5% (35 of 68 patients). Recurrent thrombosis occurred more frequently in patients with mutation MTHFR. Three and more episodes of thrombosis were registered in 17 of 40 patients with mutation C677T against 9 of 44 patients without the mutations (p = 0.04).
Conclusion: Relationship between elevated blood levels of APL and MTHFR mutation points to the fact that this genetic marker is an additional thrombogenic factor in APS. Mutation C677T in MTHFR gene in APS patients correlates with recurrent thrombosis.