2.2 Therapy regimens and sampling
All patients receiving disease-modifying anti-rheumatic drugs (DMARDs) had to be on stable doses for at least 12 weeks before being included in the study (Supplementary Table1). The patients with RA in the group of99Tc were treated with 99Tc-MDP without oral glucocorticoids for 10 days as a course, whereas the patients in another group of 99Tc & GC were given99Tc-MDP and oral glucocorticoids. The dose of Oral glucocorticoids (prednisone or methylprednisolone) has been limited at ≤ 10mg/day and has been stable for at least 4 weeks.99Tc-MDP is composed of agent A (0.05ug99Tc solution in a vial, 5ml) and B (5mg Methylenediphosphonic acid and 0.5mg stannous chloride, lyophilized). Agent A and B were mixed together for 5 minutes before ready to use.99Tc-MDP was given as daily intravenous drips of 16.5 mg diluted with 250 ml normal saline for 10 days. Fasting blood samples from RA patients were collected at the beginning of treatment of99Tc-MDP and on day 10 complied with procedure of hospital policies. These samples were transferred immediately to clinical lab for test.
Detection of inflammatory markers and Lipid profile
The laboratory parameters of patients were determined by the hospital clinical laboratory. ESR was measured by Monitor 20 (Electa lab, Italy) and CRP was detected using nephelometry on BN II (Siemens, Germany). The lipid profiles were performed by an automatic biochemistry analyzer 7600-20 (HITACHI, Japan) including TC, TG, and HDL-C, LDL-C, ApoA1, and ApoB. Atherogenic index was calculated by the equation (Atherogenic index = TC / HDL-C, TC is total cholesterol) and combined with the ratio of ApoB /ApoA1 to evaluate the risk of cardiovascular events.
Statistical analysis
The data was presented by mean ± SD including inflammatory markers and lipid profiles. The data of inflammatory markers and lipid profiles after treatment compared to baseline was analyzed by t test. difference is significant with P < 0.05. The correlation of between inflammatory markers and lipid profiles were computed using residuals by non-parameter Spearman correlation analysis and line regression analysis. The residual is equal to the value of post-treatment minus the value of baseline. The forementioned statistical analysis was run by software Graphic Pad Prism8.0.