DIFFERENCE OF SERUM LEVELS OF TYPE-IV COLLAGEN 7S BETWEEN EARLY OR OVERT NEPHROPATHY AND NONDIABETIC RENAL-DISEASE IN DIABETIC-PATIENTS WITH MICROALBUMINURIA OR MACROALBUMINURIA

We determined serum levels of type IV collagen 7S (IV 7S) in 73 (23 wi th normoalbuminuria, 21 with microalbuminuria, 17 with macroalbuminuri a, and 12 primarily affected by nondiabetic renal disease (NDRD)) and 24 (10 with only macroangiopathy and 14 with retinopathy and macroangi opathy) diabetic patients to see whether IV 7S can be a useful index f or differentiating early or overt diabetic nephropathy from NDRD in mi cro- or macroalbuminuric diabetics. IV 7S was significantly elevated i n diabetic patients with micro- or macroalbuminuria compared to those with normoalbuminuria and healthy controls (p < 0.001), On the contrar y, all 12 diabetic patients with micro- or macroalbuminuria due to NDR D showed normal or low IV 7S level. IV 7S was significantly higher in diabetic patients with both retinopathy and macroangiopathy than in th ose with only macroangiopathy (p < 0.001). We conclude that IV 7S leve ls may be a useful index to differentiate diabetic early or overt neph ropathy from NDRD, especially nephrosclerosis, in micro- or macroalbum inuric diabetics.