An atypical case of refractory passenger lymphocyte syndrome after renal transplantation

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. 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. 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. El síndrome de linfocitos pasajeros (PLS) causa hemólisis inmunomediada en receptores de trasplantes sólidos y de médula ósea. Los anticuerpos derivados del donante contra el eritrocito receptor impulsan la patogénesis. Es una entidad rara en el trasplante de riñón y la mayoría de los casos son autolimitados. Una mujer de 36 años presentó fatiga 13 días después del trasplante renal de donante vivo. La operación transcurrió sin incidentes y fue dada de alta con las funciones normales del injerto el día 11 del trasplante. Los hallazgos coincidían con la enfermedad por crioaglutininas en el momento de su ingreso. Sin embargo, la prueba de crioaglutininas fue negativa. Finalmente, le diagnosticaron PLS. La paciente también presentó hemólisis intravascular ref