A recently developed spot test, "MPS paper," has been added to other screening tests for urinary mucopolysaccharides. The effectiveness of this test has been compared to that of the cetytrimethylammonium bromide and the acid albumin gross turbidity tests in normal children and in patients with mucopolysaccharidoses. Although all these tests are effective in the detection of excessive mucopolysaccharides in urine, their excessive sensitivity yields many weak false-positives. We found "MPS paper" test to yield 34% false-positive tests, compared to 42% for cetytrimethylammonium bromide and 8% for the acid albumin gross turbidity test.
We have concluded that the acid albumin gross turbidity is the most reliable screening test for detection of mucopolysaccharide disorders. "MPS paper" spot test has the advantage of being simple and practical, but weak positive results should be interpreted with great caution; it has the added disadvantage of being the most costly of the screening tests at the present time.