Early detection of tubular dysfunction

The determination of low-molecular-weight proteins in urine as a tool for early detection of damage to the proximal tubules is briefly discussed. Beta 2-microglobulin, retinol-binding protein and alpha 1-microglobulin are at present the most widely used markers for tubular dysfunction. The determination of beta 2-microglobulin has earlier been the method of choice, but due to its instability at low pH there are certain disadvantages. Available data indicate that alpha 1-microglobulin may replace beta 2-microglobulin for screening purposes. The low-molecular-weight proteins are at present the best markers for early detection of tubular dysfunction; other constituents are not as well suited for this, even if the determination of urine enzymes has its supporters.