The use of hepcidin as a marker for diagnosing the type of anemia in patients with high activity of rheumatoid arthritis

Abstract

Anemia is still one of the most common comorbidities that affects the prognosis of the underlying disease and the quality of life of patients.Objective: to evaluate the value of serum hepcidin level determination for the differential diagnosis of anemia of chronic disease/inflammation (ACD) in patients with active rheumatoid arthritis (RA).Material and methods. The study included 47 patients with RA with anemia consecutively admitted to V.A. Nasonova Research Institute of Rheumatology for inpatient treatment. According to WHO recommendations, the criterion for anemia was a decrease in hemoglobin level ˂ 120 g/l in women and ˂ 130 g/l in men. The control group consisted of 29 patients without anemia. In all patients, the DAS28 index was determined, and clinical and biochemical blood parameters were examined: serum iron, total iron-binding capacity of serum, hepcidin, cytokines, including interleukin (IL) 6 and tumor necrosis factor α (TNFα).Results and discussion. Of 47 patients with active RA and anemia, only 13 (28%) were diagnosed with isolated ACD. Iron deficiency anemia (IDA) was found in 17 (36%), the remaining 17 patients had a mixed genesis of anemia (ACD + IDA). Patients with isolated ACD had a statistically significant higher level of hepcidin(120.3±56.1 pg/ml) compared to the control group (90.3±37.9 pg/ml) and to patients with RA + IDA. In isolated ACD, the levels of IL6, TNFα, rheumatoid factor and antibodies to cyclic citrullinated peptide were 2 times higher (p<0.05) than in RA with iron deficiency (both in IDA and in mixed genesis of anemia). Only in isolated ACD did the hepcidin level correlate with the IL6 concentrations (r=0.8); no such correlation was found in patients with IDA and anemia of mixed origin or in patients without anemia. No correlation with TNFα levels was found in any subgroup. Conclusion. Hepcidin levels are an informative indicator for the differential diagnosis of the type of anemia during active inflammation. In RA patients with ACD, the maximum hepcidin concentration in blood serum was determined, and in IDA it was found to be lower than the reference values. The importance of the hepcidin – IL6 axis and the lack of influence of the proinflammatory cytokine TNFα on iron metabolism were demonstrated. Keywords: hepcidin; anemia; difficult-to-treat patient; rheumatoid arthritis> ˂ 0.05) than in RA with iron deficiency (both in IDA and in mixed genesis of anemia). Only in isolated ACD did the hepcidin level correlate with the IL6 concentrations (r=0.8); no such correlation was found in patients with IDA and anemia of mixed origin or in patients without anemia. No correlation with TNFα levels was found in any subgroup.Conclusion. Hepcidin levels are an informative indicator for the differential diagnosis of the type of anemia during active inflammation. In RA patients with ACD, the maximum hepcidin concentration in blood serum was determined, and in IDA it was found to be lower than the reference values. The importance of the hepcidin – IL6 axis and the lack of influence of the proinflammatory cytokine TNFα on iron metabolism were demonstrated.

Keywords

• hepcidin
• anemia
• difficult-to-treat patient
• rheumatoid arthritis