Effect of Dried Blood Spot Quality on Newborn Screening Analyte Concentrations and Recommendations for Minimum Acceptance Criteria for Sample Analysis

Abstract

BACKGROUND The analysis of dried blood spots has been used routinely for newborn screening since the early 1970s, and the number of disorders screened has expanded substantially in recent years. However, there is a lack of evidence regarding minimum blood spot quality acceptance criteria for sample analysis. METHODS Blood pools were spiked with phenylalanine, tyrosine, leucine, methionine, octanoylcarnitine, decanoylcarnitine, isovalerylcarnitine, glutarylcarnitine, thyroid-stimulating hormone, and immunoreactive trypsinogen to concentrations at the analytical cutoffs used in UK screening protocols. We evaluated the effect of sample volume applied to the card (10, 20, 50, 75, and 100 μL), punch location (central vs peripheral), and sample quality (double layering, applying blood to both sides of the filter paper, multispotting, applying insufficient sample, and compressing the sample after application). RESULTS Compression of blood spots produced significantly lower results (14%–44%) for all analytes measured (P < 0.001). Smaller blood spots produced significantly lower results (15%–24% for 10-μL vs 50-μL sample size) for all analytes at all concentrations measured (P < 0.001). Results obtained from peripheral punches were higher than those from a central punch, although this did not reach statistical significance for all analytes. Insufficient and multispotted samples demonstrated heterogeneous results. CONCLUSIONS All blood spots containing ≤20 μL (blood spot diameter <8 mm), those in which blood has not fully penetrated the filter paper, and all samples with evidence of compression should be rejected, since there is a risk of producing false-negative results.

Maternal glutamine supplementation in murine succinic semialdehyde dehydrogenase deficiency, a disorder of γ‐aminobutyric acid metabolism

“…Amino acid analysis on dried blood spots has been the method of choice for newborn screening in humans . This method was found convenient for amino acids (AA) analysis in small volumes of mouse blood and implemented in our studies.…”

“…Amino acid analysis on dried blood spots has been the method of choice for newborn screening in humans. [41][42][43] This method was found convenient for amino acids (AA) analysis in small volumes of mouse blood and implemented in our studies. However, the uniformity of blood spotting on the paper cards was variable, resulting in variable blood volumes extracted from each 3-mm card punch.…”

Performance of laboratory tests used to measure blood phenylalanine for the monitoring of patients with phenylketonuria

“…The exact preparation of the DBS calibrator varies between laboratories, for example, volume of blood added to the filter paper, varying hematocrit of the specimen, or use of lysed blood specimens can all affect the measured concentration. [15][16][17][18] More importantly, the method used to assign DBS calibrator values can influence the analytical result.…”

A kinetic assay of total lipase activity for detecting lysosomal acid lipase deficiency (LAL‐D) and the molecular characterization of 18 LAL‐D patients from Russia

“…In 4.3% of the examined DBS, we observed a low LAL activity without detectable LIPA alterations. A reduced enzymatic activity in DBS is usually ascribed to poor specimen quality . DBS with gross preparation errors, such as clotting, disturbed integrity, low volume, and microbiological contamination, can be detected by visual inspection and excluded from analysis.…”

“…A reduced enzymatic activity in DBS is usually ascribed to poor specimen quality. 14,15 DBS with gross preparation errors, such as clotting, disturbed integrity, low volume, and microbiological contamination, can be detected by visual inspection and excluded from analysis. However, obscure DBS failures, such as hematocrit or blood cell count variations, are difficult to assess.…”