Possibility of Using Soluble Transferrin Receptor as a Marker of Anemia of Chronic Diseases in Rheumatic Patients
Purpose. To study the features of secretion of soluble transferrin receptor (sTfR) in patients with rheumatic pathology with anemia of chronic diseases and iron deficiency anemia. To assess the effect of interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-1β (IL-1β), interferon gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α) on sTfR. To study the possibility of using sTfR as a marker for differential diagnosis of anemia of chronic diseases and iron deficiency anemia in rheumatic patients. Materials and Methods. 126 rheumatic patients, 34 men (45.8 (36-54.9) years old), 92 women (49.5 (38-60) years old) were examined. Group 1 consisted of 41 patients with ACD, group 2 - 34 patients with iron deficiency anemia (IDA), group 3 - 29 patients with a combination of ACD and IDA, the control group - 22 patients without anemia. A comparative analysis was performed between the groups with and without anemia on the hemogram parameters, iron metabolism, and C-reactive protein (CRP). Correlation analysis was performed between the sTfR, hemogram indicators, interleukin-6 (IL-6), IL-1β, IL-10, interferon gamma (INF-γ), tumor necrosis factor alpha (TNF-α). Results. In the ACD group, the concentrations of ferritin and CRP are increased in comparison with other groups. In patients with ACD, ACD / IDA, and IDA, a higher concentration of sTfR was found in comparison with patients without anemia (p<0.05). In patients of three groups with anemia, there were no intergroup differences in the concentration of sTfR (p>0.05). There was revealed the negative correlation between the concentration of sTfR and hemoglobin (r=-0.5) and the number of erythrocytes (r =-0.7). The relationship between the concentrations of sTfR and IL-6 (r=0.4), IL-10 (r=0.6), INF-γ (r=0.4) and IL-1β (r=0.3) was proved. Conclusion. In rheumatic patients with ACD and IDA, no significant differences were found in the concentration of the soluble transferrin receptor; in both types of anemia, the concentrations of this receptor increase. Thus, in patients with rheumatic pathology, the use of sTfR for differential diagnosis of ACD and IDA is inappropriate. The revealed correlations between sTfR and cytokines indicate their influence on the synthesis of this receptor. Further studies of possible markers for the differential diagnosis of ACD and IDA are needed, including in rheumatic patients.