The -174G/C Interleukin-6 Gene Promoter Polymorphism as a Genetic Marker of Differences in Therapeutic Response to Methotrexate and Leflunomide in Rheumatoid Arthritis

Table 2

Comparison of clinical and laboratory characteristics at the baseline between GG genotype carriers and GC or CC genotype carriers.

	GG	GC or CC
Sociodemographic characteristics
Females, n (%)	51 (94.4)	42 (100)	0.25
Age (yr), mean ± SD			0.93
Disease characteristics
Disease duration (yr), mean ± SD			0.36
DAS-28 score, mean ± SD			0.87
HAQ-Di score, mean ± SD			0.98
Rheumatoid Factor (RF) (IU/mL), mean ± SD			0.009
Erythrocyte Sedimentation Rate (ESR) (mm/h), mean ± SD			0.02
IL-6 serum levels (pg/mL), mean ± SD			0.08
Treatment characteristics
Glucocorticoid dose (mg), mean ± SD			0.06
Methotrexate (MTX) n (%)	33 (61.1)	17 (55)	0.39
Leflunomide (LEF), n (%)	21 (39.0)	14 (45)

GG: excisable homozygote genotype; GC: heterozygote genotype; CC: homozygote genotype; RA: rheumatoid arthritis; HAQ-Di: Health Assessment Questionnaire-Disability index; DAS-28: modified Disease Activity Score (28 joints); IL-6: interleukin-6 serum levels. Qualitative variables were expressed in frequencies (%); quantitative variables were expressed in means ± standard deviations (SD). Comparisons between differences in proportions were performed with chi-square test (or Fisher exact test if applicable). Comparisons between differences in means were performed using independent samples Student’s -tests.