The −174G/C and −572G/C Interleukin 6 Promoter Gene Polymorphisms in Mexican Patients with Rheumatoid Arthritis: A Case-Control Study

Table 2

Clinical and laboratory characteristics of patients with RA.

Characteristic	RA; 𝑛=137
Disease duration (years), mean ± SD	10±7.9
Females (%)	135 (98.5)
DAS-28, mean ± SD	4.1±1.5
HAQ-DI, mean ± SD	0.67±0.6
Laboratory findings
Serum Rheumatoid factor (UI/L), mean ± SD	200.5 ± 384.9
C-reactive protein (mg/L), mean ± SD	17.0 ± 25.9
Erythrocyte sedimentation rate (mm/h),; mean ± SD	30.7 ± 12.6

Quantitative variables are expressed as means ± standard deviations (SD) and qualitative variables as frequencies and percentages (%) as noted. Abbreviations: RA: rheumatoid arthritis, DAS-28: disease activity score of 28 joints, HAQ-DI: Health Assessment Questionnaire Disability Index.