Urinary beta 2-microglobulin excretion and renal lithiasis.

We assessed beta 2-microglobulin excretion in 42 active calcium oxalate stone-formers, 16 active struvite stone-formers, 4 active uric acid stone-formers, 14 inactive stone-formers and 21 non-stone-forming controls. The average excretion value was within normal limits for all groups and no significant differences existed. These observations coupled with previous findings of increased low molecular weight urinary proteins in active calcium oxalate stone-formers suggest the existence of specific alterations in tubular function in this specific group.