The aim of the study was to study the predictive value of FAR and CAR in order to provide a new predictive biomarkers for the disease activity and prognosis.

A total of 150 participants were included in a Case-Control study:

1. Healthy control group: this group contains 50 healthy individual.
2. Lupus simplex (mild and moderate disease activity) group: this group contains 50 patients with a systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) score less than 15.
3. Severe disease activity group: this group contains 50 patients with a systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) score ≥ 15.

Setting:

This study will be conducted to All patients will enter to The Rheumatology Department, Sohag University Hospital for one year.

Inclusion criteria:

Patients diagnosed as SLE according to SLICC 2012 or ACE/EULAR 2017 classification criteria with

1. ≥18 years of age.
2. Complete clinical and laboratory investigations.
3. No concomitant infection, systemic or other autoimmune diseases.

Exclusion criteria:

Patients were excluded from the study if they had any of the following:

1. <18 years of age,

2. Incomplete clinical data and laboratory indicators.

3. End-stage kidney disease (defned as requiring dialysis, kidney transplantation, or estimated glomerular fltration rate (eGFR)<15 mL/min/1.73 m2

4. Patients with:

   1. Acute infectious diseases, HIV infection carriers,
   2. Concomitant systemic diseases such as chronic obstructive lung disease, coronary artery disease, cancer, thyroid function disorder, hematological disorders, acute or chronic liver and renal diseases.
   3. Patients with had other autoimmune diseases, such as rheumatoid arthritis, systemic sclerosis, or primary Sjogren's syndrome.

Methods:

All patients will be subjected to the following:

1. Thorough medical history from the patients

2. Full clinical examination including:

   1. General examination and vital signs.
   2. Complete rheumatological examination.
   3. Systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) score.

3. Laboratory examinations include:

1. Complete blood picture (CBC). 2. Erythrocyte sedimentation rate (ESR). 3. C-reactive protein (CRP) 4. Liver function tests (LFT). 5. Renal investigations:

1. Kidney functions
2. Urine analysis
3. 24 hours protein in urine and/or A/C ratio or p/c ratio.
4. eGFR
5. Renal biopsy. 6. ANA by IF. 4. Specific tests: a. Fibrinogen to Albumin ratio (FAR). b. C-Reactive protein to Albumin Ratio (CAR).

Inclusion Criteria:

Patients diagnosed as SLE according to SLICC 2012 or ACE/EULAR 2017 classification criteria with

1. ≥18 years of age.
2. Complete clinical and laboratory investigations.
3. No concomitant infection, systemic or other autoimmune diseases.

Exclusion Criteria:

Patients were excluded from the study if they had any of the following:

1. <18 years of age,

2. Incomplete clinical data and laboratory indicators.

3. End-stage kidney disease (defned as requiring dialysis, kidney transplantation, or estimated glomerular fltration rate (eGFR)<15 mL/min/1.73 m2

4. Patients with:

   1. Acute infectious diseases, HIV infection carriers,
   2. Concomitant systemic diseases such as chronic obstructive lung disease, coronary artery disease, cancer, thyroid function disorder, hematological disorders, acute or chronic liver and renal diseases.
   3. Patients with had other autoimmune diseases, such as rheumatoid arthritis, systemic sclerosis, or primary Sjogren's syndrome.

A total of 150 participants were included in a Case-Control study:

1. Healthy control group: this group contains 50 healthy individual.
2. Lupus simplex (mild and moderate disease activity) group: this group contains 50 patients with a systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) score less than 15.
3. Severe disease activity group: this group contains 50 patients with a systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) score ≥ 15.