Sensitive competitive-binding ELISAs for quantifying free kappa and lambda light chains in cerebrospinal fluid.
Simple, sensitive, and fully standardized solid-phase enzyme-linked competitive binding immunoassays to quantify free kappa and lambda immunoglobulin light chains are described. The assays were developed to measure the concentration of free light chains in cerebrospinal fluid (CSF), in part because elevated levels of free kappa light chains have utility as a diagnostic marker for multiple sclerosis (MS). Polyclonal rabbit antibodies raised against pooled Bence Jones proteins are bound to solid-phase Staphylococcal protein A and used as the primary antisera in this assay. A pool of Bence Jones proteins isolated from the urine of 10 individuals with multiple myeloma are used as a biotin-labeled ligand and to develop a standard curve. The assays as described are sensitive to the low nanogram range and are specific for free kappa or lambda light chains. The assays were found to have acceptable precision, and results correlated highly with concentrations determined using competitive-binding radioimmunoassays previously described.
Stanescu
G L
GL
Mellen Center for Multiple Sclerosis Treatment and Research, Cleveland Clinic Foundation, Ohio 44195.
Swick
A R
AR
Tuohy
V K
VK
Rudick
R A
RA
D001667:Binding, Competitive; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000134:cerebrospinal fluid*; D007146:Immunoglobulin lambda-Chains / Q000134:cerebrospinal fluid*; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid* / Q000175:diagnosis
D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains