Hicks Rebecca A, Yee Jennifer K, Mao Catherine S, Graham Steve, Kharrazi Martin, Lorey Fred, Lee W P
Division of Endocrinology, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, 1124 West Carson Street, Bldg RB-1, Box 446, Torrance, CA 90502, USA.
Genetic Disease Screening Program, California Department of Public Health, 850 Marina Bay Parkway, Richmond, CA 94804, USA.
Metabolomics. 2014 Feb 1;10(1):123-131. doi: 10.1007/s11306-013-0558-1.
Precursor-to-product ratios in steroid hormone metabolism may accurately reflect enzymatic activity and production of metabolites relative to their disappearance. The purpose of this study was to explore the use of direct precursor-to-product steroid ratios to discriminate between infants with congenital adrenal hyperplasia (CAH) due to 21- α -hydroxylase deficiency and infants with no disorder, thus characterizing the biochemical phenotype in CAH. Deidentified dried blood spot samples from confirmed CAH cases identified by newborn screen (CAH-positive, = 8) and from cases with no disorder (CAH-negative, = 10) were obtained from the California State Newborn Screening Program. Samples (∼6.25 mm circular spots) underwent methanol and water extraction (9:1 ratio). Deuterated steroids served as isotope internal standards. 17-α-hydroxyprogesterone (17-OHP), 11-deoxycortisol (S), androstenedione (A4) and cortisol (F) concentrations were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the 17-OHP/S, 17-OHP/A4, and S/F ratios were calculated. The mean 17-OHP and A4 concentrations in samples from CAH cases were significantly increased when compared to cases with no disorder ( = 0.003 for both). 17-OHP/S and 17-OHP/A4 ratios were also significantly elevated in CAH cases ( = 0.007 and < 0.001, respectively). In contrast, S and F concentrations and the S/F ratio were similar between the two groups. In CAH, the elevated 17-OHP/S ratio is a biomarker of diminished 21-α-hydroxylase activity, and the elevated 17-OHP/A4 ratio is a biomarker of adrenal androgen excess via increased 17,20-lyase activity. The similar S/F ratio indicates that the rate of production via 11-β-hydroxylase and disappearance of F is maintained in CAH.
类固醇激素代谢中的前体与产物比率可准确反映酶活性以及代谢产物的生成与消失情况。本研究的目的是探讨直接的类固醇前体与产物比率用于区分因21-α-羟化酶缺乏所致先天性肾上腺皮质增生症（CAH）的婴儿与无疾病婴儿的用途，从而明确CAH的生化表型。从加利福尼亚州新生儿筛查项目获取了经新生儿筛查确诊的CAH病例（CAH阳性，n = 8）和无疾病病例（CAH阴性，n = 10）的身份信息已去除的干血斑样本。样本（约6.25毫米圆形斑点）采用甲醇和水按9:1比例进行提取。氘代类固醇用作同位素内标。通过液相色谱-串联质谱法（LC-MS/MS）测定17-α-羟孕酮（17-OHP）、11-脱氧皮质醇（S）、雄烯二酮（A4）和皮质醇（F）的浓度，并计算17-OHP/S、17-OHP/A4和S/F比率。与无疾病病例相比，CAH病例样本中的17-OHP和A4平均浓度显著升高（两者均P = 0.003）。CAH病例中的17-OHP/S和17-OHP/A4比率也显著升高（分别为P = 0.007和P < 0.001）。相比之下，两组之间的S和F浓度以及S/F比率相似。在CAH中，升高的17-OHP/S比率是21-α-羟化酶活性降低的生物标志物，而升高的17-OHP/A4比率是通过增加17,20-裂解酶活性导致肾上腺雄激素过量的生物标志物。相似的S/F比率表明CAH中通过11-β-羟化酶的生成速率和F的消失速率保持不变。
