Decreased urinary concentrations of type IV collagen in amyotrophic lateral sclerosis

Objectives - Type IV collagen (IV-C) abnormalities of skin and serum have b een reported in patients with amyotrophic lateral sclerosis (ALS). However, there has been no study of urinary IV-C in ALS. The present study investig ates urinary IV-C and the relation to its skin content in patients with ALS . Material and methods - We studied IV-C immunoreactivity of skin and measu red urinary levels of IV-C in ALS patients and controls. Results - The base ment membrane as well as blood vessels of skin in ALS patients was weakly p ositive for IV-C as compared with those of controls. Immunostaining became even weaker as ALS progressed. The urinary level of IV-C in ALS patients wa s significantly decreased as compared to diseased controls (P<0.001) and he althy controls (P<0.001), and was negatively and significantly associated w ith duration of symptoms (r=-0.85, P<0.001). There was an appreciable posit ive correlation between urinary IV-C levels and the density for IV-C immuno reactivity in ALS patients (r=0.84, P<0.01). Conclusion - These data sugges t that a metabolic alteration of IV-C may occur in ALS patients and decreas ed levels of urinary IV-C may be related to the decreased IV-C immunoreacti vity of skin in ALS.