IL-4可变串联重复序列区基因多态性在小儿激素敏感性肾病综合征复发中的意义

Significance of polymorphisms in variable number of tandem repeat region of interleukin-4 gene in recurrence of childhood steroid sensitive nephrotic syndrome

目的探讨IL-4基因VNTR区的基因多态性与小儿激素敏感性肾病综合征复发的关系。方法选择激素敏感性肾病综合征患儿55例,按发病后1年疾病复发情况分为频复发组28例和非频复发组27例(40例有肾活检资料)。对照组115例,选自健康献血员。采用聚合酶链式反应(PCR)及PCR产物测序方法,检测患儿与对照组IL-4基因VNTR区的基因型别。对48例患儿于发病初(频复发组23例,非频复发组25例)检测其血清IgE水平。结果(1)激素敏感性肾病综合征患儿和对照组IL-4基因VNTR区的基因型的分布差异无统计学意义(P>0·05)。(2)频复发组B1B1分布频率(96·4%)明显高于非频复发组(66·7%)(P<0·05)。(3)发病初期血清中IgE水平:频复发组为(1·98±0·23)g/L,非频复发组为(1·05±0·19)g/L(P<0·05)。B1B1组IgE水平为(1·68±0·18)g/L,B1B2和B2B2组为(0·81±0·21)g/L(P<0·05)。结论激素敏感性肾病综合征患儿携带IL-4VNTR区的B1B1基因型者,容易表现为频复发。

Objective Recent studies suggest that T cell dysfunction, especially IL-4, may be involved in the pathogenesis of steroid sensitive nephrotic syndrome (SSNS). The aim of this study was to investigate the association between the polymorphisms in variable numbers of tandem repeat region (VTR) of IL-4 gene and childhood SSNS. Method The polymorphism in the IL-4 gene was identified by using the polymerase chain reaction and direct sequencing methods in 55 Chinese children with SSNS, who were followed-up for at least 1 year, and 115 healthy Chinese adult blood donors as controls. A variable numbes of tandem repeat (VNTR) region polymorphisms of IL-4 gene were detected, and alleles were designated as IL-4 B1 and B2, corresponding to 2 and 3 repeats, respectively. The serum IgE was also examined in 48 patients before the steroid treatment. Result (1)There were no significant differences in the genotype and allele frequencies between patients with SSNS and normal controls ( P >0.05). (2)The frequencies of B1B1 (96.4%) were significantly higher in SSNS children with frequent relapses (28 patients had more than 3 relapses during the first year of the disease) than in 27 patients without frequent relapses ( P <0.05). (3)Twenty-three patients with frequent relapses showed higher levels of serum IgE (1.98±0.23g/L) than 25 patients (IgE:1.05±0.19g/L) without frequent relapses ( P <0.05), and the patients with B1B1 (38 patients) also had higher serum IgE levels than patients with B1B2 and B2B2 (10 patients) ( P <0.05). Conclusion The results suggest that IL-4 VNTR B1B1 genotype might be a predictor for the frequent relapse in childhood SSNS in Chinese.