Screening study on excretion pattern of urinary glycosaminoglycans from orthopedic patients

To obtain a clue for the metabolic disorder of glycosaminoglycans (GAG) in orthopedic diseases, a screening study on excretion pattern of urinary GAG from orthopedic patients was performed by the procedures of Nagatsuka et al. (1980). All the urines examined gave three regular GAG-bands. Besides the regular bands, some samples gave irregular bands. Of 123 cases examined in the present study, the numbers of cases with an abnormal excretion pattern of urinary GAG in the regular bands (A) and with the irregular band(s) (B) were as follows: 23(A) and 7(B) in 38 cases of rheumatoid arthritis (RA); 8(A) and 5(B) in 13 cases of malignant bone tumor; 11(A) and 3(B) in 12 cases of benign bone tumor; 16(A) and 3(B) in 25 cases of bone metabolic and connective tissue diseases; 6(A) and 4(B) in 9 cases of osteaorthritis; 6(A) and 3(B) in 8 cases of spine diseases; and 14(A) and 8(B) in 18 cases of other orthopedic diseases. The excretion patterns of urinary GAG suggested that the metabolic rates of chondroitin sulfates tended to elevate in most cases of (A). Also, certain metabolic disorder of dermatan sulfate and heparan sulfate was suggested in several cases of (A). In addition, the abnormal metabolism of acidic glycoprotein(s) was suggested in many cases of (B). Excretion of a large amount of dermatan sulfate was elucidated in one case (Case 20 of bone metabolic and connective tissue diseases) by digestion with chondroitinases after the screening study. Therefore, the metabolic disorder of dermatan sulfate was indicated in this patient. The low activity of alpha-L-iduronidase in her urine supported this indication. This patient was finally diagnosed as mucopolysaccharidosis I-S (Scheie syndrome).