Development of tandem mass spectrometry-based creatinine measurement using dried blood spot for newborn mass screening

Abstract

BackgroundCongenital anomalies of the kidney and urinary tract (CAKUT) are the most prevalent etiologies of pediatric chronic kidney disease (CKD). However, no robust mass screening methods have been developed to detect patients with CAKUT, making early intervention to prevent progressive renal failure challenging.MethodsWe applied tandem mass spectrometry (MS/MS) to measure the creatinine (Cr) value from dried blood spot (DBS) analysis, which has been used for newborn mass screening. Subsequently, we evaluated the correlation between DBS Cr measured by MS/MS and serum Cr measured by the conventional method in pediatric patients with CKD. Finally, DBS Cr was measured in 190 full-term, healthy newborns on days 4-6 after birth.ResultsWe established a system of MS/MS-based measurement of Cr from DBS. Measured DBS Cr in the pediatric patients showed a strong association with serum Cr (r=0.86; P<0.01). The median DBS Cr value in newborns was 0.222 (interquartile range: 0.189, 0.269) mg/dl. No significant correlations were found between DBS Cr values and body weight, Apgar score, gestational age, and sex in newborns.ConclusionWe successfully established a method for MS/MS-based measurement of Cr for newborn screening and determined normal reference values for full-term newborns.

Pharmacokinetic considerations related to therapeutic drug monitoring of tacrolimus in kidney transplant patients

“…In addition, it would be extremely useful if multiple components could be assessed in the same sample. Of note, a DBS assay that measures other immunosuppressants and serum creatinine would meet a clinical need [43,44].…”

Preparation of Isotopically Labelled Standards of Creatinine Via H/D Exchange and Their Application in Quantitative Analysis by LC-MS

“…There are several ways of determining both the serum and urine creatinine concentrations, such as ELISA [1], colorimetry [2], Cre biosensor [3], capillary electrophoresis with electrochemical detection [4], quantitative 1 H-NMR [5], LC-UV [6], GC-MS and LC-MS [7] Liquid chromatography-mass spectrometry is currently the method of choice in the quantitative analysis of Cre, due to its sensitivity, low-cost and potential for analysis of complex mixtures [8][9][10]. The LC-MS-based Cre quantification methods comprise the addition of defined quantities of isotopically-labeled standard (isotopologue) to the analyzed sample, for the absolute quantification using the isotope-dilution method [11,12].…”

“…Additionally, introduced isotopes cannot undergo back-exchange during LC-MS separation conditions. Although isotope-labeled creatinine standards are commercially available (Cre-d 3 and Cre-d 5 ) and widely used for analysis [8,10], due to their complicated and expensive synthesis their price is high. Therefore, the development of new methods of isotopically-labeled creatinine standards synthesis is still under investigation.…”

Comparison of blood serum protein analysis by MALDI-MS from either conventional frozen samples or storage disc-deposited samples: A study with human serum from pregnant donors and from patients with intrauterine growth restriction

“…13 Dried blood spots have been prepared on filter paper cards which provide a suitable storage and shipment device for clinical samples 13 and analysis of small molecules, such as phospholipids, creatinine, and drug metabolites by mass spectrometry has been successful upon resolubilization. [14][15][16] While quantitation of blood proteins from dried blood spots can be done by multiple reaction monitoring mass spectrometry (MRM MS) analysis of enzymatically generated partial peptides, [17][18][19] elution of intact proteins and subsequent analysis by mass spectrometry to generate a proteome profile has not yet been reported. A suitable means to avoid demanding and costly serum freezing was storing and shipping of serum as so-called ''dried serum spots''.…”

“…20 Dried blood spots have found wide-spread application for sampling of specimen in the clinics 21 and analysis of small molecules by mass spectrometry from these sources has become routine even for screening of larger populations. 14–16 Dried blood spot sampling as well as dried serum spot sampling was preferred, particularly because freeze/thaw cycles 22 can be avoided.…”