Prognostic significance of basement membrane antigens and of soluble interleukin 2 receptor serum concentrations in heart transplant rejection.

Endomyocardial biopsy is still considered the only reliable method for diagnosing acute rejection. However, because of its invasive nature, this procedure cannot be performed on a daily basis. Therefore, for the noninvasive monitoring of transplanted patients, we tested the sensitivity of serum levels of basement membrane antigens, type IV collagen fragment NC1 and laminin fragment P1 (LP1), of antibodies against laminin and type IV collagen, and of soluble interleukin 2 receptor (sIL2R). In 17 patients who underwent heart transplantation no correlation was found between the degree of rejection and the levels of antibodies to type IV collagen and laminin. Serum laminin P1 and sIL2-R values were found increased in all the study groups even in absence of rejection; however, sIL2R levels were higher in patients with more severe rejection. NC1 levels were found significantly higher in patients with mild or moderate rejection than in those with no rejection or in controls. These preliminary data suggest a possible predictive role of basement membrane antigens in cardiac rejection, but further studies in a larger group of transplanted patients are needed.