Rheumatoid arthritis is an autoimmune disease characterized by synovial inflammation and joint destruction that follows a relapsing - remitting course and induce severe disability . Rheumatoid arthritis is an inflammatory disease that causes devastating joint destruction if patients are not appropriately treated. It is characterized by symmetric joint involvement, erosion and deformity in the joints as a result of synovial inflammation .Inflammation is the key determinant and primary underlying mechanism leading to disability and increased mortality in patients with rheumatoid arthritis.Disease activity assessment is important for rheumatoid arthritis management, since it could greatly affect the clinical decision. Current disease activity assessment mainly depend on clinical symptoms, signs and laboratory tests. laboratory Investigations are much preferred due to the advantage of less observer variations.
Therefore assessment of inflammation in rheumatoid arthritis with reliable markers is crucial to predict long term outcome of a particular patient. The most commonly used markers for this purpose are ESR and CRP in daily practice. However both of these markers have some limitations such as reflection of short-term inflammatory activity and low discrimination ability with other superimposed conditions.
Systemic inflammation is associated with changes in circulating blood cells quantity and composition. Normochromic anemia, thrombocytosis, neutrophilia and lymphopenia usually occur with many inflammatory conditions so the features of circulating blood cell components can be used for the assessment of inflammatory activity .
Parameters of hemogram, particularly those including immune system elements are important in the assessment of different diseases and or sign. Immune system elements involve the neutrophils, lymphocytes and platelets that have a role in the control of inflammation, while also undergoing changes secondary to inflammation. Patients with rheumatoid arthritis may be found with increasing platelet counts during active stages of the disease. The counts decrease up on remission of inflammation but detailed role played by platelets remains unobvious .
Platelet count, mean platelet volume (MPV), platelet distribution width (PDW) are three useful indices of platelet function reflecting the platelet production rate. .
Gokmen et al 2016 concluded that MPV and neutrophil lymphocyte ratio (NLR) together with acute phase reactant C.reactive Protein(CRP), erythrocyte sedimentation rate (ESR) can be a useful indices for showing inflammation in RA patients and demonstrated that MPV negatively correlated with CRP and NLR positively correlated with ESR, CRP and anti cyclic citrullinated peptide antibody (antiCCP). The author concluded that high NLR levels in patients with RA is important in predicting prognosis of disease and development of more joint damage and hypothesized that NLR may be Considered to be an indicator of inflammation, disease activity and disease prognosis.
Previous studies have shown that increased neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are associated with poor prognosis of various inflammatory related diseases such as cancer, chronic kidney disease , acute pancreatitis ) and myocardial infarction . This may be due to the fact that both PLR and NLR are associated with the inflammatory status .
Based on these Studies recently Fu el at., in 2015 hypothesized that both NLR and PLR correlated with the disease activity of RA and suggested that NLR and PLR may be indices for assessment of RA disease activity.
Uslu et al 2015 demonstrated that NLR and PLR were elevated in rheumatoid arthritis patients with active disease compared with patients in remission. So they concluded that NLR and PLR were two new inflammatory markers which could be used to assess disease activity in patients with rheumatoid arthritis
