Zhang Xiao-yan, Zhao Shun-ying, Jiang Zai-fang
Department of Pediatric Internal Medicine, Beijing Children's Hospital Affiliated to The Capital Medical University, Beijing 100045, China.
Zhonghua Er Ke Za Zhi. 2009 Feb;47(2):83-6.
Galactomannan (GM) is a major aspergilli cell-wall constituent released into circulation during the early stage of invasive disease, and can be detected. Many studies suggest that serum galactomannan assay has an excellent sensitivity and specificity for the early diagnosis of adult invasive aspergillosis (IA). However, there have been few studies on serum galactomannan assay in pediatric patients. Therefore, we evaluate the value of serum galactomannan assay in the diagnosis of pediatric invasive pulmonary aspergillosis in this study.
Blood samples were obtained from 88 children, of whom 14 had definitive or possible invasive pulmonary aspergillosis (IPA), 16 had other invasive pulmonary fungal infection and 58 had pulmonary non-fungal infection. Of the 58 patients, 23 had bacterial pneumonia, 20 had mycoplasma pneumonia and 15 had pulmonary tuberculosis. A double-direct sandwich ELISA was employed to detect GM optical density index (ODI) in the serum sample. GM ODI were observed before and after treatment in six children with IPA. Measurement data followed the Gaussian distribution were expressed as x(-) +/- s; differences among groups were tested using a single factor analysis of variance. If the s>1/3 x(-), measurement data were expressed as M [minimum, maximum], and the differences among groups were tested by a rank sum test. P < 0.05 was considered to be statistically significant.
The serum GM ODI in IPA group [1.03 (0.16 - 3.73)] was significantly higher than that in the other invasive pulmonary fungal infection group [0.30 (0.04 - 1.28)] and pulmonary non-fungal infection group [0.24 (0.08 - 0.69)] (P < 0.05). If the cut-off GM ODI was set at 0.5, the sensitivity and specificity of the assay for IPA were 71.4% and 91.9% respectively. The accuracy rate for IPA was 88.6%. If the cut-off GM ODI was set at 0.8, the sensitivity, specificity and accuracy rate for IPA were 64.2%, 98.6% and 93.2% respectively. Of 6 children whose GM were observed serially, GM ODI declined consistently with the clinical remission in 3 children. GM ODI raised in 2 children corresponding to clinical exacerbation. Whereas GM ODI elevated paradoxically regardless of clinical remission in the remaining one patient.
Serum GM detection was an effective method for the diagnosis of pediatric IPA.
半乳甘露聚糖（GM）是曲霉细胞壁的主要成分，在侵袭性疾病早期释放到循环系统中，可被检测到。许多研究表明，血清半乳甘露聚糖检测对成人侵袭性曲霉病（IA）的早期诊断具有出色的敏感性和特异性。然而，关于血清半乳甘露聚糖检测在儿科患者中的研究较少。因此，本研究评估血清半乳甘露聚糖检测在儿科侵袭性肺曲霉病诊断中的价值。
采集88例儿童的血样，其中14例确诊或可能患有侵袭性肺曲霉病（IPA），16例患有其他侵袭性肺部真菌感染，58例患有肺部非真菌感染。在58例患者中，23例患有细菌性肺炎，20例患有支原体肺炎，15例患有肺结核。采用双夹心ELISA法检测血清样本中的GM光密度指数（ODI）。观察6例IPA患儿治疗前后的GM ODI。符合高斯分布的计量资料以x(-)±s表示；组间差异采用单因素方差分析进行检验。若s>1/3x(-)，计量资料以M[最小值,最大值]表示，组间差异采用秩和检验。P<0.05认为差异有统计学意义。
IPA组血清GM ODI[1.03(0.16 - 3.73)]显著高于其他侵袭性肺部真菌感染组[0.30(0.04 - 1.28)]和肺部非真菌感染组0.24(0.08 - 0.69)。若将GM ODI临界值设定为0.5，该检测方法对IPA的敏感性和特异性分别为71.4%和91.9%。IPA的准确率为88.6%。若将GM ODI临界值设定为0.8，IPA的敏感性、特异性和准确率分别为64.2%、98.6%和93.2%。在6例连续观察GM的患儿中，3例患儿的GM ODI随临床缓解而持续下降。2例患儿的GM ODI随临床病情加重而升高。而其余1例患儿的GM ODI无论临床是否缓解均出现反常升高。
血清GM检测是诊断儿科IPA的有效方法。
