2.1 Patients with RA and evaluation of disease activity
Sixty-nine patients with RA who fulfilled the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) for RA were given a 10-day treatment with 99Tc-MDP or and oral glucocorticoids at the First Affiliated Hospital of Xiamen University in period of Feb. 2019 ~ Dec. 2020 [27]. According with different therapy regimens, they were divided into two groups including 99Tc-MDP (n = 27, as99Tc) and combined with oral glucocorticoids (n = 42, as 99Tc & GC) (Table1). Exclusion criteria included the combination of other autoimmune diseases (including secondary Sjögren’s syndrome), hematological system, liver or kidney dysfunction (≥ 1.5 times of the upper limit of the cutoff value), pregnant women, oral hypolipidemic drugs and receiving intra-articular injection of corticosteroids in the last four weeks. None of the patients had diabetes mellitus, impaired glucose tolerance, and cerebrovascular diseases, cardiovascular disease, thyroid dysfunction, nephrotic syndrome, alcoholism, chronic liver disease, Cushing syndrome or obesity (body mass index > 30 kg/m2). Based on retrospective observation, the study was approved by the Medical Ethics Committee at the First affiliated Hospital of Xiamen University (KY202015-034).
The disease activities of the patients with RA were evaluated by erythrocyte sedimentation rate (ESR), C reactive protein (CRP) and disease activity score 28 for rheumatoid arthritis with ESR or CRP (DAS28ESR, DAS28CRP). DAS28ESR was calculated following the equations: DAS28ESR = [0.56 × SQRT (T28) +0.28 × SQRT (SW28) + 0.70 × LN (ESR)] ×1.08 +0.16, DAS28CRP = [0.56 × SQRT (T28) +0.28 × SQRT (SW28) + 0.36 × LN (CRP + 1)] ×1.10 + 1.15, where SQRT is the square root, LN is logarithm, T28 is the number of total tender joints out of 28 joints and SW28 is the number of total swollen joints out of 28 joints. Twenty-eight joints including bilateral proximal interphalangeal joints, bilateral metacarpophalangeal joints, and bilateral wrist joints, bilateral elbow joints, bilateral shoulder joints and bilateral knee joints.