Rheumatoid arthritis is a chronic systemic inflammatory and autoimmune disease, characterized by disordered immunity, not regulated cytokines and inflammatory infiltration of the synovial joints. It is the most common inflammatory erosive poly arthritis affecting around 0.5-1% of the worldwide population which leads to joint damage and disability

The etiology of Rheumatoid arthritis is complex, it is established that the gene environmental interaction plays critical roles in the pathology of Rheumatoid arthritis, in addition to smoking, lifestyle, and hormones.

The lesion is mainly concentrated in the synovial tissue, cartilage, and bone. Inflammation is the primary cause of joint deformation and limited joint mobility in Rheumatoid arthritis patients. As the disease progresses, the risk of bone damage and cartilage destruction increases, leading to substantial disability.

The activity of the disease in Rheumatoid arthritis patients is assessed by clinical examination, laboratory tests and radio graphic assessment. Laboratory assessment of Rheumatoid arthritis activity is done routinely by measuring acute phase reactants such as an erythrocyte sedimentation rate and C-reactive protein, which are elevated in active Rheumatoid arthritis patients.

Albumin is the major plasma protein and its determination is used for the prognostic assessment of several diseases. It is a routine marker reflecting both nutritional status and systemic inflammation, and the synthesis of albumin can be suppressed by systematic inflammation and malnutrition.

It was reported that the level of albumin was decreased in Rheumatoid arthritis patients. This low concentration of albumin in Rheumatoid arthritis patients may owing to excessive albumin consumption caused by inflammatory substances.

Red blood cell distribution width is a parameter that reflects the heterogeneity of erythrocyte volume, expressed as the coefficient of variation of red blood cell volume. It is mainly used to differentiate types of anemia. However, some studies have shown that an elevated Red blood cell distribution was positively correlated with the level of inflammation.

Red blood cell distribution was increased in patients with Rheumatoid arthritis, which was associated with inflammation, suggesting that Red blood cell distribution may be a potential auxiliary marker for indicating inflammation process in Rheumatoid arthritis conveniently.

In subjects with articular pain, Red blood cell distribution interpretation is a useful tool in clinical practice to distinguish between articular inflammatory and non-inflammatory joint diseases, as with C-reactive protein. Red blood cell distribution seems to be a surrogate marker of the inflammatory process.

Inclusion Criteria:

• Adult RA Patients who fulfilled the 2010 European league against rheumatism criteria for the classification of RA

Exclusion Criteria:1. Individuals with concomitant other autoimmune diseases 2. RA patients with anemia, pregnancy, postpartum, diabetes, obesity hypertension.

3. Patients with age less than 18 years 4. Patients with end stage organ failure.

5. Patients with liver diseases.

6. Patients with hematological disorders.

7. Patients with malignancies

The study will include adult RA patients consecutively presented at the Rheumatology, Rehabilitation and Physical Medicine Department, Assiut University Hospitals from both inpatient department and outpatient clinic.

study the relation between RDW and level of serum albumin in RA patients and association with the disease activity and severity.