| Objectiveâ‘ To investigate the relationship between the C/T polymorphism in the CD40 gene position1 site and the relapse of GD after antithyroid withdrawal in Shandong Qingdao Han population.â‘¡To investigate factors associated with the early relapse of Graves'hyperthyroidism after antithyroid withdrawal.Methodsâ‘ 198 patients, including 80 GD initial onset patients,84 early relapse and 34 late relapse patients, and 110 healthy controls were studied. The genotype and allele frequencies were assayed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).â‘¡We retrospectively analyzed 118 GD relapse patients, which were treated in our hospital from 2008 to 2009.We recorded their age, gender, level of goiter, exophthalmos, family history, relapse history, duration of drug treatment and so on.Resultsâ‘ Significant differences were observed in CD40 gene between GD and control group (X2= 23.133, P= 0.000; X2=13.372, P=0.000). The CC genotype frequency was significantly higher in GD group than that in control (23.7%vs 11.8%).The TT genotype frequency was significantly lower in GD group than that in control (7.6%vs 26.4%). The C allele frequency was significantly higher in GD group than that in control (58.1%vs 42.7%).â‘¡Significant differences were observed in CD40 genotype frequencies between GD onset and relapse group (X2=7.926, P=0.019). The TT genotype frequency was significantly lower in GD relapse group than that in onset (3.4%vs 13.8%.But the significant differences in allele frequencies were not observed (X2=0.665, P=0.415).â‘¢Significant differences were also observed in CD40 gene genotype frequencies between GD early relapse and late relapse group (X2=11.278, P=0.004). However, the significant differences in allele frequencies were not observed (X2=2.272, P=0.099).â‘£We found significant difference in age, level of goiter, course of treatment and relapse history(P<0.05), but did not find significant difference in gender, exophthalmos, family history, drug type and urinary iodine levels between GD early relapse and late relapse groups (P>0.05)Conclusionâ‘ The polymorphism of C allele in CD40 gene position 1 site is associated with the susceptibility to the development and relapse of GD in Shandong Qingdao Han population.â‘¡The age, level of goiter and relapse history is associated with the early relapse of GD. |