Increased deposition of types III and V collagen in neurofibroma tissue from patients with von Recklinghausen disease.

Collagen components in neurofibroma tissue from patients with von Recklinghausen disease were investigated, in comparison with those in normal skin and peripheral nerve tissue. Biochemical analysis of collagen isolated from the tissues by limited pepsin digestion indicated that the neurofibroma tissue contained type I collagen as the major constituent and increased amounts of types III and V collagen. The relative ratios of alpha 1(III)/alpha 1(I) and alpha 1(V) + alpha 2(V)/alpha 1(I) in the tissue were 0.87-0.92 and 0.16-0.17, respectively, while in normal skin, these ratios were 0.36-0.45 and less than 0.024, respectively. Amino acid analysis and circular dichroism studies of types I, III and V collagen purified from the tissue showed that these collagens were essentially the same as the corresponding types of collagen isolated from fetal human skin and placenta. The increased deposition of types III and V collagen suggested that alternation of collagen metabolism had occurred in the neurofibroma tissue.