Urinary myelin basic protein-like material as a correlate of the progression of multiple sclerosis

In the multicenter, randomized, placebo‐controlled trial of alternate‐day injections of recombinant interferon beta‐1b in relapsing‐remitting multiple sclerosis (MS), urine specimens were collected periodically from all patients (n = 64) in two of the clinical test sites over the 2 years of the study. Urine specimens were also collected over two consecutive 24‐hour periods from 43 patients from a third center. Urine samples were assayed for their content of myelin basic protein‐like material (MBPLM), the level of which was correlated with clinical changes, cranial magnetic resonance imaging results, and the development of progressive disease. Concordant changes in creatinine values affected some of the relationships of MBPLM. The level of urinary MBPLM correlated with a chronic progressive course and with the number of lesions and the total lesion area on cranial magnetic resonance images. A rise in the level of urinary MBPLM appeared to antedate the clinical transition from a relapsing‐remitting to a chronic progressive course. By chance, the randomized entry of patients led to significant differences in urinary MBPLM levels among the three treatment groups, thus precluding correlation studies of treatment effects. However, the patient group from which 24‐hour specimens were collected showed that the patients with relapsing‐remitting MS changing to a chronic progressive course, and more specifically, those patients with chronic progressive MS receiving placebo, had the highest values of urinary MBPLM. These findings indicate that urinary MBPLM may offer an objective test and possibly serve as a surrogate Marchker for detecting or predicting the failure of remission or the transition to a progressive phase of MS.