Figure 1.

Factors concurring to determine iron deficiency (ID) in classical inflammatory disorders.

In such conditions, serum ferritin loses its diagnostic power for identifying ID because of stimulation by pro-inflammatory cytokines. Left: inflammatory bowel diseases (IBDs), like Crohn’s disease and ulcerative colitis. Right: rheumatoid arthritis (RA) and related immunological disorders. In RA, gastrointestinal (GI) blood losses are favoured by treatment with non-steroidal anti-inflammatory drugs (NSAIDs) and antithrombotic drugs prescribed for often associated cardiovascular diseases. Proton pump inhibitors (PPI), frequently co-prescribed with NSAIDs, can contribute to decreased iron absorption by increasing gastric pH. In both IBD and RA, frequent blood drawing for laboratory analyses, especially during hospital admissions, can also contribute to causing iron deficiency. RBC: red blood cell.