Immunoglobulin Reference Ranges In An Appalachian Pediatric Population
Saturday, March 3, 2018
South Hall A2 (Convention Center)
Apoorwa Thati, MS, BS, Ahmad Al Balbissi, MD, Sumana Reddy, MD, Rodrigo Tejeida-Estrada, BS, Kevin F. Breuel, PhD, MS, Alexei Gonzalez-Estrada, MD

RATIONALE: Normal age group serum immunoglobulin reference ranges are essential during evaluation of primary immunodeficiency. Previous published data demonstrated geographical and regional variation. There is limited data on our specific region. We sought to determine reference distributions for immunoglobulin levels on pediatric age groups from the Appalachian region.

METHODS: Serum levels of IgA, IgG, IgM were measured in samples collected from 2,823 children (newborn to <18 years of age) living in the Appalachian region of the US. Data was stratified by specific age groups. Samples containing the following ICD-9 codes were eliminated: 279, 279.01, 279.03-279.06, 279.11, 279.2, 279.3, D80.2 and R80.9. Confidence intervals (with a significant level of 10%) were estimated using 912, 360 and 402 observations for IgA, IgM and IgG respectively. Data was compared to levels from the Mayo Clinic national reference laboratory.

RESULTS: IgA;IgM;IgG [mg/mL] levels were as follows: 0-5 months (NA;8.7-89.5;191.5-570.3), 5-9 months (18.1-47;26.7-109.3;186.7-638.9), 9-15 months (10.2-80.4;28.8-138.6;289.4-849.9), 15-24 months (32.4-90.1;41.3-137.4;399.1-933.9), 2-4 years (17.4-180;32.7-149.4;249.4-1254.8), 4-7 years (44.3-195;33.6-160.5;498.4-1211.2), 7-10 years (50.9-224.6;31.3-163.7;636.8-1210), 10-13 years (50-233.4;0-211.8;605.6-1352.6), 13-16 years(62.4-256.2;23.3-202.5;641.1-1348.5), and 16- <18 years (83.9-257.7;33.4-193.2;651.2-1292.2). Compared to the Mayo Clinic national reference laboratory, our IgA, IgM, and IgG ranges vary in all age groups.

CONCLUSIONS: Reference ranges for immunoglobulin levels in pediatric populations have relatively sparse consensus of data as evidenced by the variability seen between different geographic areas. Our findings however provide more standardized measurements for pediatric populations in the Appalachian region, as immunoglobulin levels are affected by a number of external factors that can be regionally specific.