Pediatric Concentrations of S100B Protein in Blood: Age- and Sex-related Changes

Abstract

nisolone produced a weak signal at a slightly different retention time. At the evaluated concentration of 5000 g/L, prednisolone produced a signal equivalent to 20 g/L cortisol, representing a 0.4% interference. Fenofibrate generated parent ions at m/z 361 and 363 in an abundance ratio of 3:1, a distinctive pattern related to the presence of chlorine in the chemical composition. In MS/MS mode, fenofibrate produced a m/z 3633121 transition that interfered with the quantitative transition of cortisol, but it did not produce the m/z 363397 transition. Thus, switching to the secondary transition for quantification eliminated interference from this drug. In addition, the elution time of the drug was ϳ30 s longer than that of cortisol.Taylor et al.(1 ) noted isotopic exchange between the deuterated IS and hydrogen-containing vapors in an APCI ion source. Unlike the observations of Taylor et al., we have not observed isotopic exchange with our APCI interface. The reason for this difference is unclear, but it may be related to ion source conditions. The good agreement obtained between our method and the comparison LC-MS/MS method suggests that isotopic exchange did not affect the proposed method.Apparently healthy adult volunteers (25 males and 25 females; age range, 19 -53 years) collected 24-h urine samples without preservative. The volunteers were asked to keep samples under refrigeration during the collection. Statistical results for this study are presented in Table 1.To evaluate agreement between the established reference interval with UFC values in the population, we evaluated results for 2089 random 24-h urine specimens analyzed with the proposed method (Fig. 1). The mean (SD) value for log-transformed UFC excretion in 24 h was 1.26 (0.24) log g/24 h (minimum and maximum, 0.3 and 3.84 log g/24 h, respectively), and skewness and kurtosis for the distribution were 1.51 and 5.57, respectively.The stability of cortisol in urine was evaluated in the presence of acetic (15 mmol/L), boric (15 mmol/L), and hydrochloric (30 mmol/L) acid. Two samples without added acid were stored and analyzed under the same conditions as the samples stored with the acids. Samples were stored at room temperature, 4°C, and Ϫ20°C and analyzed every 4 -7 days during 1 month of storage. Cortisol concentrations in samples stored with the acids were higher by ϳ30% than in samples stored without acid, possibly as a result of partial hydrolysis of sulfate and glucuronide conjugates.In conclusion, the rapid LC-MS/MS method for UFC analysis appears to be free from interference and agrees closely with a HPLC-MS/MS method that uses sample extraction. The method has been demonstrated reliable in a high-volume clinical laboratory environment.

Preanalytical, analytical, gestational and pediatric aspects of the S100B immuno-assays

“…This is the first study to report reference ranges for serum S100B protein with the DiaSorin ® method in what, to date, is the largest published population in healthy pediatric patients aged up to 16 years old. This work aligns to two similar studies done on the Roche Diagnostics ® method [7,19] and confirms the first studies of Portela et al [20] and Gazzolo et al [6] done on Sangtec ® method. Indeed, Gazzolo et al showed in their study a reference curve produced from 1004 children.…”

“…The biological data reported here provides clinicians with practical pointers for the management of mTBI in pediatric patients and could help reduce the use of currently-recommended CCT procedures in this population [4]. Our analysis of the different groups identified clearly confirms a negative correlation between S100B concentrations and age, in agreement with other reports [6][7][19][20]. Without losing sight of the differences in terms of methods, our values are also consistent with figures reported in neonates (0.43-2.7 μg/L) [21].…”

“…S100B is involved in glial cell proliferation and maturation, synaptogenesis and fiber sprouting [5]. This explanation is strongly supported by previous results, as correlation with height growth velocity [6], and by our finding that head circumference correlates to blood S100 concentration -a relationship that could be used to approximate the reference values after simple clinical examination.…”

“…S100B is one of a multigenic family of calcium-binding proteins and is predominantly expressed by central nervous system cells (mainly astroglial but also neuronal cells) [5]. S100B plays a trophic role in age dependent manner and correlates with parameters suggestive of growth as height growth velocity [6] or head circumference [7] in a gender dependent manner [6]. S100B has been clearly established as a powerful diagnostic tool (compared to CCT) for mTBI management if sample collection is performed within the first 3 hours after trauma [3].…”

The role of blood S100B and lactate levels in minor head traumas in children and adults and correlation with brain computerized tomography

“…Geyer ve arkadaşları [4] 1004 çocukta normal serum S100B seviyelerini incelemiş ve referans eğrisini çizmiştir. Gazzolo, [5] bir yaşının altında diğeri ergen dönemde olan iki pik bulmuştur. Tüm bu çalışmalar S100B'nin yaşa bağlı olduğunu kesin olarak göstermiştir ve minör travmatik beyin yaralanmalarında (TBY) S100B ile ilgili çalışmalarda yaşa spesifik referans kullanılması konusundan bahsedilmektedir, ancak bizim çalışma-mızda çocuk sayısı az olduğu için yetişkin hastalardan daha farklı referans değerleri almadık.…”