Determination of TREC and KREC reference intervals for immunodeficiency newborn screening in the Russian Federation

Abstract

In this work we used a reference population of newborns and sampled dried blood spots on Guthrie cards of 2,739 individual samples to determine the reference interval of TRECs and KRECs values in order to diagnose primary immunodeficiency due to neonatal screening. The median of absolute TRECs and KRECs values were 195 (CI95%: 185-206) and 185 (CI95%: 176-197) copies per μl, respectively, the normalized values for TREC - 2780 (CI95%: 2690-2840) and for KREC - 2790 (CI95%: 2700-2900) copies per 2x105 copies of the albumin gene or 105 cells. The reference interval was calculated for 99 and 99.9 percentiles of all TRECs and KRECs values. Due to asymmetric distribution of data to filter outliers values Tukey's criterion was applied after the logarithmic transformation of the data. When analyzing absolute values TREC / KREC per μL of blood) there no “drop-down” TRECs values were identified; for KRECs, 18 values were excluded from further analysis (from 9.8 to 13.5). Emissions are not identified for the normalized values TRECs / KRECs. The obtained reference values TRECs and KRECs (at the level of 0.1 percentile) were 458 and 32 per 105 cells, or 23 and 17 per μl of neonatal blood, respectively.

Keywords

• Primary immunodeficiency (PID)
• T-cells
• B-cells, screening
• TREC
• KREC
• newborn
• reference intervals