Background: Osteonecrosis (ON) is a known complication of SLE affecting patient's life. Aim of the work was to find out the association between polymorphism of ABCB1 gene and susceptibility to osteonecrosis of femoral head (ONFH) in SLE patients.
Subjects and methods: A case control study was done on 93 subjects who were divided into 3 groups: Group I: 31 SLE patients with ONFH, Group II: 31 SLE patients without ONFH, Group III: 31 matched healthy volunteers as a control group. ONFH was identified and staged by MRI. Genotyping of (C3435T) polymorphism was done by polymerase chain reaction restriction fragment length (PCR-RFLP) for all subjects.
Results: No statistically significant difference (P≥ 0.05) between the studied groups regarding genotypes frequency. However the percentage of genotype CC and genotype CT were more in group I (32.3%, 29%) and in group II (32.3%, 38.7%) than in controls (22.6%, 25.8%) respectively. Percentage of genotype TT was more in controls (51.6%) than in group I (38.7%) and in group II (29%). No statistically significant difference (P≥ 0.05) between groups regarding alleles frequency; however, allele C percentage was more in group I (46.8%) and in group II (51.6%) than in controls (35.5%), and allele T percentage was more in controls (64.5%) than in group I (53.2%) and in group II (48.4%).
Conclusions: No statistically significant difference between the studied groups regarding genotypes and allele frequencies; ABCB1gene polymorphisms C3435T do not increase susceptibility to ONFH in SLE patients, but future large scale studies among Egyptian patients are recommended.