Plasma and urinary levels of cytokines in patients with idiopathic hypercalciuria.
BACKGROUND
Recent studies suggest that cytokines modulate bone turnover. Idiopathic hypercalciuria (IH) seems to be associated with bone mineral loss. Therefore, the aim of this study was to assess cytokines involved in bone turnover in patients with IH.


METHODS
Plasma and spot-urine levels of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor alpha (TNF-α), transforming growth factor β1 (TGF-β1), and monocyte chemoattractant protein (MCP-1) were measured in 70 children and adolescents with IH and in 37 healthy controls. Patients with IH were subdivided according to their calciuria at the time of sample collection: ≥4 mg/kg/day (persistent IH, n=27) and below 4 mg/kg/day (controlled IH, n=43). Cytokines were determined by enzyme-linked immunoassay.


RESULTS
Plasma and urinary concentrations of IL-1β, IL-6, IL-8, and TNF-α were undetectable in all groups. No differences were found between controlled and persistent hypercalciuria for plasma and urinary levels of MCP-1 and TGF-β1. On the other hand, MCP-1 levels were significantly higher in both subgroups of IH in comparison to healthy controls. Furthermore, urinary MCP-1 levels of IH patients correlated positively with bone mineral content (p=0.013).


CONCLUSIONS
Although cytokine measurements did not allow the differentiation between persistent and controlled IH, our findings suggest that MCP-1 might play a role in patients with IH.
Pediatric Nephrology Unit, Department of Pediatrics, Faculty of Medicine, Belo Horizonte, MG, Brazil.
Augusto C S
AC
Santos
Eleonora M
EM
Lima
Maria Goretti M G
MG
Penido
Katia D
KD
Silveira
Mauro M
MM
Teixeira
Eduardo A
EA
Oliveira
Ana Cristina
AC
Simões E Silva
D015502:Absorptiometry, Photon; D000293:Adolescent; D000367:Age Factors; D015415:Biomarkers / Q000097:blood / Q000652:urine; D015519:Bone Density; D016723:Bone Remodeling; D001938:Brazil; D002118:Calcium / Q000652:urine; D016022:Case-Control Studies; D018932:Chemokine CCL2 / Q000097:blood / Q000652:urine; D002648:Child; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood* / Q000652:urine*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D053565:Hypercalciuria / Q000097:blood / Q000000981:diagnostic imaging / Q000276:immunology* / Q000652:urine; D053583:Interleukin-1beta / Q000097:blood / Q000652:urine; D015850:Interleukin-6 / Q000097:blood / Q000652:urine; D016209:Interleukin-8 / Q000097:blood / Q000652:urine; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D053773:Transforming Growth Factor beta1 / Q000097:blood / Q000652:urine; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000652:urine; D055815:Young Adult
D015415:Biomarkers; C111835:CCL2 protein, human; C508606:CXCL8 protein, human; D018932:Chemokine CCL2; D016207:Cytokines; C508600:IL6 protein, human; D053583:Interleukin-1beta; D015850:Interleukin-6; D016209:Interleukin-8; C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; D002118:Calcium