Erythrocyte blood indices and state of iron metabolism in children with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a systemic chronic disease. One of the extra-articular manifestations of JIA are hematological changes. The most common is anemia. The aim of the study was to explore the indicators of the red blood cells and the state of iron metabolism in children with JIA, depending on the form and duration of the disease. A retrospective analysis of the medical history of patients was carried out. The study of the indicators of the red blood cells consisted in determining the number of erythrocytes, the amount of hemoglobin, the ratio of the number of erythrocytes to blood volume, the average volume of erythrocytes, the average hemoglobin content in the erythrocyte, the average concentration of hemoglobin in the erythrocyte, as well as the distribution of red blood cells along the length in the form of the difference between the largest and smallest size of red blood cells and the deviation of the volume of red blood cells from the average value. The state of iron metabolism was represented by such indicators as the content of serum iron, ferritin, transferrin, latent iron-binding capacity of blood serum, total iron-binding capacity of serum, transferrin saturation coefficient with iron. In 18.7 % of children with JIA, a decrease in hemoglobin of less than 120 g/l was noted. There was a significant (p < 0.001) decrease in the average hemoglobin content in the erythrocyte in 37.9 % of patients. As a result of the study, it was found that the decrease in the iron content in the blood serum is due not only to the true iron deficiency state, but also to the redistribution of iron reserves against the background of chronic autoimmune inflammation. In the systemic form of the disease, changes in the latent iron deficiency state are more pronounced. With a long course of the disease, normalization of red blood cell parameters occurs. The duration of the disease has no effect on ferrokinetics, which is due to the development of iron deficiency compensation against the background of ongoing treatment.

1. Manners P. J., Diepeveen D. A. Prevalence of juvenile chronic arthritis in a population of 12-year-old children in urban Australia. Pediatrics, 1996, vol. 98, no. 1, pp. 84–89.

2. von Koskull S., Truckenbrodt H., Holle R., Hormann A. Incidence and prevalence of juvenile arthritis in an urban population of southern Germany: a prospective study. Annals of the Rheumatic Diseases, 2001, vol. 60, pp. 940–945.

3. Wagner N., Denneker G. (eds.). Pädiatrische Rheumatologie. 2 Aufl. Berlin, Heidelberg, Springer-Verlag, 2014. 564 p.

4. Niemeyer C., Eggert A. (eds.). Pädiatrische Hämatologie und Onkologie. 2 vollst. überarb. Aufl. Berlin, Heidelberg, Springer-Verlag, 2018. 564 p.

5. Ganz T., Nemeth E. Iron sequestration and anemia of inflammation. Seminars in Hematology, 2009, vol. 46, no. 4, pp. 387–393. https://doi.org/10.1053/j.seminhematol.2009.06.001

6. Zarychanski R., Houston D. S. Anemia of chronic disease: a harmful disorder or an adaptive, beneficial response? Canadian Medical Association Journal, 2008, vol. 12, no. 4, pp. 333–337. https://doi.org/10.1503/cmaj.071131

7. Furst D. E., Chang H., Greenberg J. D., Veena K. Prevalence of low hemoglobin levels and associations with other disease parameters in rheumatoid arthritis patients: evidence from the CORRONA registry. Clinical and Experimental Rheumatology, 2009, vol. 27, no. 4, pp. 560–566.

8. Muñoz M., García-Erce J. A., Remacha Á. F. Disorders of iron metabolism. Part II: iron deficiency and iron overload. Journal of Clinical Pathology, 2011, vol. 64, no. 4, pp. 287–296. https://doi.org/10.1136/jcp.2010.086991

9. Northrop-Clewes C. A., Thurnham D. I. Biomarkers for the differentiation of anemia and their clinical usefulness. Journal of Blood Medicine, 2013, vol. 20, no. 4, pp. 11–22. https://doi.org/10.2147/JBM.S29212

10. D’Angelo G. Role of hepcidin in the pathophysiology and diagnosis of anemia. Blood Research, 2013, vol. 48, no. 1, pp. 10–15. https://doi.org/10.5045/br.2013.48.1.10

11. Lim A. Y., Gaffney K., Scott D. G. Methotrexate-induced pancytopenia: serious and under-reported? Our experience of 25 cases in 5 years. Rheumatology (Oxford), 2005, vol. 44, no. 8, pp. 1051–1055. https://doi.org/10.1093/rheumatology/keh685