An atypical case of refractory passenger lymphocyte syndrome after renal transplantation.

BACKGROUND: Passenger lymphocyte syndrome (PLS) causes immune-mediated hemolysis in solid and bone marrow transplant recipients. Donor-derived antibodies against the recipient erythrocyte drive the pathogenesis. It is a rare entity in kidney transplantation, and most of the cases are self-limited.

CASE PRESENTATION: A 36-year-old woman presented with fatigue 13 days after living donor renal transplantation. The operation was uneventful, and she was discharged with normal graft functions on the 11th day of transplantation Findings were consistent with cold agglutinin disease at her admission. However, the cold agglutinin test was negative. Eventually, she was diagnosed with PLS. Refractory intravascular hemolysis and frank hemoglobinuria were also present in the patient. Hemolysis was resistant to steroids, intravenous immunoglobulin (IVIG), and Rituximab. Because of life-threatening anemia related to refractory PLS, mycophenolate and tacrolimus were interrupted. However, hemolysis persisted. Following that, immunoadsorption (IA) treatment was obtained. Unfortunately, graft loss occurred due to rejection despite the resolution of PLS after IA.

CONCLUSION: PLS is a rare and usually self-limited entity. Our case was an atypical refractory PLS that resembled cold agglutinin disease. Also, frank hemoglobinuria was observed related to severe intravascular hemolysis. These features have not been described before in PLS, to the best of our knowledge. Additionally, IA treatment had never been reported in the literature for PLS, as far as we know. Treatment and management could be a challenge in refractory PLS. Rituximab, IVIG, and extracorporeal treatments could be beneficial. It should be borne in mind that refractory PLS can cause graft and patient loss.