The natural history of biopsy-negative rejection after heart transplantation.

Purpose. The most recent International Society for Heart and Lung Transplantation (ISHLT) biopsy scale classifies cellular and antibody-mediated rejections. However, there are cases with acute decline in left ventricular ejection fraction (LVEF ≤ 45%) but no evidence of rejection on biopsy. Characteristics and treatment response of this biopsy negative rejection (BNR) have yet to be elucidated. Methods. Between 2002 and 2012, we found 12 cases of BNR in 11 heart transplant patients as previously defined. One of the 11 patients was treated a second time for BNR. Characteristics and response to treatment were noted. Results. 12 cases (of 11 patients) were reviewed and 11 occurred during the first year after transplant. 8 cases without heart failure symptoms were treated with an oral corticosteroids bolus and taper or intravenous immunoglobulin. Four cases with heart failure symptoms were treated with thymoglobulin, intravenous immunoglobulin, and intravenous methylprednisolone followed by an oral corticosteroids bolus and taper. Overall, 7 cases resulted in return to normal left ventricular function within a mean of 14 ± 10 days from the initial biopsy. Conclusion. BNR includes cardiac dysfunction and can be a severe form of rejection. Characteristics of these cases of rejection are described with most cases responding to appropriate therapy.