SOLUBLE HLA CLASS-I MOLECULES - BIOLOGICAL SIGNIFICANCE AND CLINICAL IMPLICATIONS

Soluble class I human leukocyte antigens (sHLAs) have been detected in serum, sweat, lymphatic fluid, urine and cerebrospinal fluid, Their b iological function has, however, remained a puzzle. The physiological concentration of sHLA varies more than tenfold depending on the phenot ype of the individual, and is significantly upregulated in various dis eases and during inflammation, This suggests that sHLAs might serve as a marker of pathological changes, Recent experiments have shown that, in vitro, sHLAs can modulate T-cell reactivity and induce cell-activa ted apoptosis, implicating sHLAs in the induction and maintenance of p eripheral tolerance, Therefore, sHLAs have the therapeutic potential t o induce tolerance to transplants.