Agudelo-Flórez Piedad, Costa-Carvalho Beatriz T, López Juan Alvaro, Redher Jussara, Newburger Peter E, Olalla-Saad Sara Teresinha, Condino-Neto Antonio
Center for Investigation in Pediatrics and Department of Pediatrics, State University of Campinas Medical School, Campinas, Brazil.
Am J Hematol. 2004 Mar;75(3):151-6. doi: 10.1002/ajh.10477.
Patients with severe leukocyte G6PD deficiency may present with impairment of NADPH oxidase activity and a history of recurrent infections, mimicking the phenotype of chronic granulomatous disease. We report herein a child with recurrent infections who initially received the diagnosis of G6PD deficiency. His erythrocyte G6PD activity was reduced: 1.8 U/g Hb (normal: 12.1 +/- 2.1 U/g Hb). Further studies revealed that G6PD activity in neutrophils, mononuclear leukocytes, and Epstein-Barr virus-transformed B-lymphocytes from the proband was similar to healthy controls. Molecular studies showed that the G6PD deficiency was due a 202 G-->A mutation, the A- variant common in African ethnic groups. The proband also exhibited severely impaired respiratory burst activity, as observed in X-linked CGD. Sequence analysis of genomic DNA showed a 264 G-->A substitution at the 3' splice junction of gp91-phox exon 3. The cDNA sequence showed a deletion of gp91-phox exon 3, giving rise to an unstable or nonfunctional mutant gp91-phox and to the phenotype of X-linked CGD. We propose that clinicians treating a patient with G6PD deficiency during a severe infection episode consider the possibility of temporary or permanent impairment of the phagocytes' microbicidal activity and the eventual association of G6PD deficiency and chronic granulomatous disease.
严重白细胞葡萄糖-6-磷酸脱氢酶(G6PD)缺乏症患者可能出现NADPH氧化酶活性受损及反复感染史,酷似慢性肉芽肿病的表型。我们在此报告一名反复感染的儿童,最初被诊断为G6PD缺乏症。其红细胞G6PD活性降低:1.8 U/g Hb(正常:12.1±2.1 U/g Hb)。进一步研究显示,先证者中性粒细胞、单核白细胞及爱泼斯坦-巴尔病毒转化的B淋巴细胞中的G6PD活性与健康对照相似。分子研究表明,G6PD缺乏是由202 G→A突变所致,该A变异体在非洲族裔群体中常见。先证者还表现出严重受损的呼吸爆发活性,这在X连锁慢性肉芽肿病中可见。基因组DNA序列分析显示,gp91-phox外显子3的3'剪接连接处有264 G→A替换。cDNA序列显示gp91-phox外显子3缺失,产生不稳定或无功能的突变型gp91-phox,导致X连锁慢性肉芽肿病的表型。我们建议,临床医生在严重感染发作期间治疗G6PD缺乏症患者时,应考虑吞噬细胞杀菌活性暂时或永久受损的可能性,以及G6PD缺乏症与慢性肉芽肿病最终关联的可能性。