The change of serum complement factor B and its clinical implication in children with primary IgA nephropathy / 中华实用儿科临床杂志

ABSTRACT

Objective:To detect serum level of complement factor B (CFB), and to explore its correlations with clinical parameters and prognosis in children with primary IgA nephropathy (IgAN).Methods:A total of 204 children with primary IgAN confirmed by kidney biopsy in the Department of Nephrology of the First Affiliated Hospital of Zhengzhou University from December 2014 to April 2017 were included in IgAN group.During the same period, 84 healthy children were included in healthy control group.Their mean age was (11.0±3.5) years and (10.9±3.2) years, respectively.Patients in IgAN group were divided into low CFB group (102 cases) and high CFB group (102 cases) according to the medium serum level of CFB measured by enzyme-linked immunosorbent assay. Spearman′ s coefficient was employed to analyze correlation amongst various parameters.Multivariable-adjusted Cox proportional ha-zards models were used to evaluate the relationship between serum CFB level and prognosis in children with IgAN. Results:Serum CFB levels were significantly higher in IgAN group than that in healthy control group [290.9 (186.2-453.9) mg/L vs.218.9 (155.0-321.3) mg/L, Z=-3.372, P=0.001]. Serum levels of CFB were negatively correlated with serum albumin ( r=-0.388, P<0.001) and estimated glomerular filtration rate ( r=-0.416, P<0.001), but positively correlated with serum creatinine ( r=0.305, P<0.001) and 24 h urinary protein ( r=0.456, P<0.001) in IgAN group.The incidences of crescents (C1-2) (70.6% vs.29.4%, χ2=34.588, P<0.001) and C 3 deposition (+ + -+ + + ) (63.7% vs.44.1%, χ2=7.892, P=0.005) were significantly higher in high CFB group than those in low CFB group. Kaplan- Meier analysis showed that high CFB levels predicted worse renal outcome in pediatric IgAN patients ( χ2=17.509, P<0.001). Multivariate Cox regression analysis showed that the high CFB level was the independent risk factor for the poor renal outcome ( HR=2.517, 95% CI 1.284-4.932, P=0.007). Conclusions:High serum levels of CFB are associated with decreased renal function, increased urinary protein excretion, crescentic formation and poor renal outcome in pediatric IgAN patients.