Evaluation of interleukin-1 and -6 in the etiopathogenesis of idiopathic osteoporosis and osteopenia in children.
BACKGROUND
The aim of the study is to determine whether serum concentrations of interleukin (IL)-1and IL-6 correlate with indices of bone mineral metabolism in children with idiopathic osteoporosis and osteopenia.


METHODS
The study comprised 62 patients aged 6-18 years (20 with idiopathic osteoporosis, 22 with idiopathic osteopenia, and 20 controls). In 10 children, investigations were repeated after one year of treatment. Serum concentrations of IL-1alpha, IL-1beta, IL-1 receptor antagonist (IL-1ra), as well as IL-6 and its soluble receptor (IL-6sR) were determined by the ELISA method. In patients with decreased bone mass, selected calcium-phosphorus metabolism indices and bone turnover markers were assessed.


RESULTS
Higher values of IL-6 were recorded in those with idiopathic osteoporosis than in controls (2.79 vs. 1.43; p<0.05). In these patients there was also a tendency towards higher values of IL-6sR (p=0.05). IL-1alpha and IL-1beta were not markedly elevated in any of the patients. No significant differences between groups regarding IL-1ra were observed. Negative correlation between IL-6, IL-1alpha, cytokine/receptor indices, and spinal bone mineral density was determined. Positive correlation was found between IL-alpha, IL-1/IL-1ra, and parathormon as well as between IL-1alpha, IL-6sR, and bone formation markers.markers. Increase in bone mass after treatment was accompanied by a decrease in IL-6sR.


CONCLUSIONS
The higher serum levels of IL-6 in children with idiopathic osteoporosis/osteopenia and the decrease in IL-6sR after treatment reveal an involvement of IL-6 in the etiopathogenesis of these disturbances. The results suggest that IL-1 may also participate in the primary decrease of bone mass in children.
Rusińska
Agnieszka
A
Department of Pediatric Propedeutics and Metabolic Bone Diseases, Institute of Pediatrics,Medical University of Łódź, Poland.
Chlebna-Sokół
Danuta
D
D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology* / Q000378:metabolism*; D016022:Case-Control Studies; D002648:Child; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000097:blood / Q000502:physiology; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000097:blood / Q000378:metabolism / Q000502:physiology; D010024:Osteoporosis / Q000209:etiology* / Q000378:metabolism*; D019947:Receptors, Interleukin-6 / Q000097:blood; D012795:Sialoglycoproteins / Q000097:blood; D013997:Time Factors
D016207:Cytokines; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; D012795:Sialoglycoproteins