title: Filter paper-based insulin-like growth factor assay.
abstract: This study assessed validity, reliability, and feasibility of a filter paper blood spot insulin-like growth factor 1 (IGF-1) assay for retinopathy of prematurity (ROP) research. Blood samples were collected from 45 healthy children. Half of each sample was spun to obtain serum; half was applied to filter cards and stored for varying times and at different temperatures. IGF-1 assays were performed using a commercially available kit. Intraclass correlation between blood spot and serum IGF-1 values was high (0.97) for validity, and the mean differences were low for test-retest reliability. Time (up to 25 days) and temperature (4° C to 37° C) had no significant effect on sample stability. Feasibility was further assessed in a second cohort study of 74 premature infants being screened for ROP. A total of 817 filter card samples were successfully collected and transported to a central lab, where IGF-1 assays were successfully performed.
authors.affiliation: Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Jensen
authors.affiliation: Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia.
authors.forename: Carrie
authors.initials: C
authors.lastname: Coleman
authors.affiliation: Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia.
authors.forename: David
authors.initials: D
authors.lastname: Stokes
authors.affiliation: Biochemistry Core Laboratory, Clinical Translational Research Center, The Children's Hosptial of Philadelphia, Philadelphia.
authors.forename: Gui-shuang
authors.initials: GS
authors.lastname: Ying
authors.affiliation: Biochemistry Core Laboratory, Clinical Translational Research Center, The Children's Hosptial of Philadelphia, Philadelphia.
authors.forename: Jiayan
authors.initials: J
authors.lastname: Huang
authors.affiliation: Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
authors.forename: Ivy
authors.initials: I
authors.lastname: Kuhn
authors.affiliation: Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia. Electronic address: binenbaum@email.chop.edu.
authors.forename: Gil
authors.initials: G
authors.lastname: Binenbaum
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D001800:Blood Specimen Collection / Q000379:methods; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005240:Feasibility Studies; D005385:Fingers / Q000098:blood supply; D005865:Gestational Age; D064368:Healthy Volunteers; D006801:Humans; D007223:Infant; D007234:Infant, Premature / Q000097:blood; D019102:Infant, Very Low Birth Weight; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D010209:Paper; D015203:Reproducibility of Results; D012178:Retinopathy of Prematurity / Q000097:blood*
chemical_list: D007334:Insulin-Like Growth Factor I