Free light chains in multiple sclerosis urine

We measured free kappa (κ) and lambda (λ) light chains in urine from patients with definite multiple sclerosis (MS), other neurologic diseases (OND), and normal controls by using an enzyme linked immunosorbent assay. Both κ and λ light chains were higher in MS than OND or controls. In seven of eight relapsing-remitting (R-R) MS patients serial studies showed that urinary κ chains were elevated during periods of worsening, and decreased during clinical recovery. In contrast, the levels of κ chains did not correlate with clinical activity in 10 progressive (P) MS patients. Further correlation of urinary light chains with neurologic evaluations in R-R and P MS patients over a longer period are needed to determine their clinical and biological relevance.