Rheumatoid arthritis is a chronic inflammatory disease that affects the joints, causing symmetric pain, stiffness, swelling, and limited motion and function of multiple joints, its fibro inflammatory manifestations may develop in other organs.

Rheumatoid arthritis is complicated by lung manifestations, such as interstitial lung disease which is the most common cause of morbidity and mortality in rheumatoid arthritis patients. Rheumatoid arthritis-interstitial lung disease is a progressive fibrotic disease of the lung parenchyma that includes a broad spectrum of disorders such as nonspecific interstitial pneumonia, usual interstitial pneumonia , desquamative interstitial pneumonia, cryptogenic organizing pneumonia, diffuse alveolar damage, acute interstitial pneumonia, and lymphocytic interstitial pneumonia . Rheumatoid arthritis-interstitial lung disease in which available data indicate that dysregulated inflammatory cascades can elaborate a host of cytokines, chemokines, and growth factors that collectively promote epithelial and endothelial cell damage, angiogenesis, fibroblast differentiation/proliferation, and lung fibrosis . Given the clinical implications of putative signaling cascades involved in these processes, biomarkers that can be used to clarify disease pathogenesis and identify factors governing disease progression are clearly needed .

Inclusion Criteria:

1. Adult rheumatoid arthritis patients who fulfilled the 2010 American College of Rheumatology/European league against rheumatism criteria for the classification of Rheumatoid Arthritis.
2. Adult rheumatoid arthritis patients with interstitial lung disease.

Exclusion Criteria:

1. Individuals with other autoimmune diseases (systemic lupus erythematosus, polyarteritis nodosa, dermatomyositis, scleroderma, spondyloarthritis and inflammatory bowel disease).
2. Individuals with hepatitis, Rhinovirus infection, cerebral malaria.
3. Individuals with colorectal carcinoma, syndrome of frailty, vetiligo.