*4.1. Study Participants*

The present study is prospective–observational and included 82 SLE patients and 40 healthy subjects. All the patients signed the informed consent, the Declaration of Helsinki from 1975 was respected. The study was developed between 2018 and 2021, and patients over 18 years old were selected from those who attended the Clinical Hospital of Nephrology "Carol Davila" and Clinical Hospital "Victor Babes". The study protocol was approved by the Ethics Committee of Clinical Hospital of Nephrology "Carol Davila" (11/23.07.2018). Of these 82 SLE patients, 44 had SLE with cutaneous and hematological determinations, but no lupus nephritis (non-LN group), while 38 had lupus nephritis (LN group) diagnosed by biopsy puncture and histological exam according to KDIGO guidelines. The activity and chronicity index of lupus nephritis was evaluated and it is presented in Table 9. In LN patients, 7% had type II LN, 18% had type III LN, 70% had type IV and 5% type V. SLE diagnosis was established according to Systemic Lupus International Collaborating Clinics/American College of Rheumatology criteria. The activity disease was based on clinical Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). The time lapse of disease and ongoing treatment (non-steroidal anti-inflammatory drugs, corticosteroids, hydroxychlorochine, immunosuppressant drugs such as azathioprine, mycophenolate mophetil, antihypertensive therapy) were recorded for each patient. The exclusion criteria were the presence of any cardiovascular, hepatic, thyroid, gastrointestinal, or oncological disease, any viral or bacterial infections in the last three months, tobacco use, drug abuse, alcoholism, use of vitamin or other antioxidant supplements, and pregnancy.

**Table 9.** Activity and chronicity index in lupus nephritis.



## **Table 9.** *Cont.*
