Increased free light chains in the urine from patients with multiple sclerosis

Mehta, P. D. PhD
Cook, S. D. MD
Troiano, R. A. MD
Coyle, P. K. MD

New York State Institute for Basic Research in Developmental Disabilities (Dr. Mehta), Staten Island, NY; UMDNJ-New Jersey School of Medicine (Drs. Cook and Troiano), Newark, NJ; and the Health Sciences Center (Dr. Coyle), SUNY at Stony Brook, Stony Brook, NY.

Address correspondence and reprint requests to Dr. P.D. Mehta, Department of Immunology, NY State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY 10314.

Supported in part by a grant from the National Multiple Sclerosis Society.

Presented in part at the 41st annual meeting of the American Academy of Neurology, Chicago, IL, April 1989.

Received April 16, 1990. Accepted for publication in final form October 5, 1990.

Neurology 41(4):p 540-544, April 1991.

Article abstract

We quantitated free kappa (κ) and lambda light (L) chains in coded urine specimens from subjects with clinically definite multiple sclerosis (MS) (N = 56), other neurologic diseases (OND) (N = 30), and age-matched normal controls (N = 28). Urine from MS patients showed statistically significant increases in free L chains compared with the other groups, although there was overlap between MS patients and OND patients. The ratio of κ/creatinine was significantly greater in the relapsing-remitting MS group than in patients with clinically stable MS, OND, and normal controls. Elevated free L chains were usually independent of urinary albumin and β₂-microglobulin levels. Serial studies showed that urinary free κ/creatinine ratios were elevated during periods of clinical worsening in seven of eight MS patients and subsequently decreased during clinical recovery. The measurement of free L chains in urine obtained at intervals from MS patients may be useful as a marker to monitor disease activity.