HEMATOLOGICAL ABNORMALITIES IN RHEUMATOID ARTHRITIS: PREVALENCE, MECHANISMS, AND CLINICAL IMPLICATIONS

Abstract

Rheumatoid Arthritis (RA) is a chronic systemic autoimmune disease that is not only marked by persistent synovial inflammation and consequent joint destruction but is also accompanied by a variety of extra-articular manifestations. Amongst the hematologic manifestations of RA, which are highly prevalent and significant in nature, the present article attempts to provide an overview of the hematologic abnormalities in the condition of RA. Chronic systemic inflammation is known to play a pivotal role in the derangement of normal hematopoiesis, through the mechanism of pro-inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1 (IL-1). Amongst the hematologic abnormalities, anemia, especially anemia of chronic disease, is the most common manifestation of RA and is observed in 30-60% of RA patients. Iron deficiency anemia and hemolytic anemia are other hematologic abnormalities that are observed in RA. In addition, abnormal leukocyte count is also observed in RA. These abnormal leukocyte counts are in the form of leukocytosis, neutropenia, and abnormal functioning of lymphocytes. In addition, abnormal platelet count in the form of reactive thrombocytosis and thrombocytopenia is also observed. An important complication of Felty’s Syndrome, which is a rare but severe complication that involves the combination of RA, neutropenia, and splenomegaly, thereby increasing susceptibility to infections. Moreover, there is an increased risk of lymphoproliferative syndromes in RA patients. In addition, the pharmacological interventions in RA have been reviewed in the article. These interventions include conventional and biologic disease-modifying antirheumatic drugs (DMARDs), which may have both ameliorative and causative effects on hematologic disorders. In the evaluation of RA, laboratory investigations are essential. These include complete blood count, peripheral smear, iron profile, and inflammatory markers. In certain cases, bone marrow examination is also carried out. It is essential to understand the relationship between inflammation, immune system dysfunction, and hematopoiesis in RA. New biomarkers and targeted therapies are important in the management of hematologic manifestations in RA.