Among the most prevalent hematologic abnormalities in patients with rheumatologic disorders are the anemia of chronic disease (ACD), a mild anemia that is generally asymptomatic, and iron deficiency anemia.
In iron-deficiency anemia, the TIBC would higher than 400–450 mcg/dL because stores would be low.
Patients with RA occasionally have concurrent iron deficiency anemia and ACD. When this occurs, the hemoglobin level usually drops to below 9.5 g/dL, and the MCV is less than 80.
FA 2018 page 409. Associated with inflammation (RA, SLE, CKD).