BACKGROUND: This case describes passenger lymphocyte syndrome (PLS) generating human platelet antigen 1a (HPA-1a) alloantibodies against the recipient\'s platelets after liver transplant. Given the rarity of PLS, especially in liver transplant with HPA-1a alloantibodies, disease course and management options are poorly described.
METHODS: The patient had cirrhosis secondary to nonalcoholic steatohepatitis complicated by hepatocellular carcinoma, encephalopathy, and severe ascites. The model for end-stage liver disease (MELD) score was 15 at presentation. The patient developed hepatic artery thrombosis after an orthotopic liver transplant and was relisted for transplant with a MELD score of 40. The patient received a hepatitis C virus antibody positive, hepatitis C virus nucleic amplification test positive donor liver on postoperative day (POD) 7 after first transplant. On POD 7 after the second transplant, the patient developed profound thrombocytopenia refractory to platelet infusion. They were found to have serum antibody to HPA-1a based upon serum platelet alloantibody testing. The donor was later found to be negative for HPA-1a by genetic testing. However, the patient\'s native platelets were HPA-1a positive. The patient was diagnosed with PLS.
RESULTS: The patient\'s treatment course included 57 units of platelets transfused, emergency splenectomy, rituximab, plasma exchange, intravenous immunoglobulin (IVIG), eltrombopag, romiplostim, and efgartigimod.
CONCLUSIONS: The synergistic effect of efgartigimod with eltrombopag and romiplostim most likely resolved the patient\'s thrombocytopenia. This case represents a novel use of efgartigimod in the treatment of passenger lymphocyte syndrome following liver transplant.

People with group O blood are considered universal organ donors compatible with any other blood group. However, in the case of minor ABO-incompatible transplantation, immune-mediated hemolysis may occur due to concomitant transfer of donor B lymphocytes together with the allograft. These passenger lymphocytes can produce antibodies in the recipients erythrocytes, causing hemolytic anemia known as passenger lymphocyte syndrome (PLS).
A retrospective chart review was performed.
A 6-year-old boy (A+) underwent transplantation of a kidney from his father (O+). On postoperative day (POD) 6, the patient developed fever with no explainable causes. On POD 11, he presented with abdominal pain, hematochezia, and severe diarrhea, with sudden hemolytic anemia. Since then, GI symptoms have continued. On POD 20, direct antiglobulin test (DAT) was positive, and the anti-A IgM/G titer was 2/32. The results of the anti-A antibody elution test were strongly positive (3+). These findings highly suggested PLS. On the same day, the GI symptoms suddenly worsened, and laboratory findings showed hemolysis and thrombocytopenia with disseminated intravascular coagulation (DIC). Abdominal computed tomography (CT) scans suggested ischemic colitis of venous origin, and the patient underwent segmental colectomy with ileostomy formation on POD 23. To remove the anti-A antibodies, the patient underwent therapeutic plasma exchange (TPE) five times until the DAT and anti-A elution test were negative.
We report a case of gastrointestinal involvement of PLS that occurred after minor ABO-incompatible kidney transplantation. This is the first report of ischemic colitis as an atypical manifestation of PLS.

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.

Passenger lymphocyte syndrome (PLS) is a well-described phenomenon causing immune hemolytic anemia, mostly in non-ABO identical transplantations. The syndrome occurs when donor lymphocytes produce antibodies against the recipient\'s red blood cells. Although the syndrome is usually self-limited, further management with blood transfusions, immunosuppression, or plasmapheresis might be needed. A 23-year-old female with AB+ blood group underwent small intestine transplantation from a deceased donor with O+ blood group. She received rituximab, thymoglobin, and methylprednisolone as immunosuppressive induction. In the 9th postoperation day, she developed hemolysis which was primarily managed with blood transfusions and finally ceased by plasmapheresis and intravenous immunoglobulin. Few cases of PLS have been previously described in intestinal transplantation recipients. Correct diagnosis and management prevents severe hemolysis outcomes. Previous cases have been successfully treated with a combination of immune suppression, plasma exchange, and transfusions.

Passenger lymphocyte syndrome (PLS) is a rare post solid organ transplantation complication, usually occurring after ABO- or Rh-mismatched transplantation. In general, PLS can lead to severe hemolytic anemia, but it is usually a self-limited disease. Most PLS cases start with a decreased hemoglobin (Hb) level and require donor type RBC transfusion as the only treatment.
In our case, the allograft was given by an O-type Rh-D(+) donor and received by an A-type Rh-D(+) recipient. The PLS was developed on the post-operative day (POD) 10 with an increased indirect bilirubin (IDBIL) level as the first clinical symptom, while the Hb level did not significantly decrease. The PLS was diagnosed on POD 17 by a direct antiglobulin test (DAT) and a blood group test. The patient quickly became stable on POD 18 after a total of eight units of O-type RBC transfusion. Kidney function was uneventful in the entire PLS period.
In ABO-mismatched kidney transplantation, an increased level of IDBIL should be considered as the first symptom of PLS even without an Hb decrease. The kidney function may be not affected by the PLS symptoms.

Passenger lymphocyte syndrome (PLS) is an immune-mediated hemolysis that occurs after ABO-mismatched kidney transplantation. PLS is caused by donor lymphocytes producing antibodies to recipient red blood cells, resulting in hemolysis. The incidence of PLS has been reported to be approximately 20% in patients with ABO-mismatched groups. Nevertheless, there is no comprehensive review of PLS following renal transplantation. In this review, we systematically summarized the data of patients with PLS after renal transplantation to help clinicians diagnose and treat more effectively.
A systematic review was conducted using PubMed, Embase, and Web of Science. All relevant data were collected, including age, sex, and clinical and immune parameters.
A total of 91 published cases were identified. The age ranged from 9 to 70 years old and 58.2% were male. Eighty-six cases were only kidney transplantations, one was liver-kidney transplantation, three were pancreas-kidney transplantations, and one was intestinal-kidney transplantation. Of these cases, 27 received kidneys from deceased donors, whereas 40 received kidneys from living donors. Most patients showed immune hemolysis dominated by anaemia, which was significantly improved after symptomatic support treatment, such as blood transfusion and erythropoietin injection.
PLS is an immune-mediated disease that can occur in patients with ABO-mismatched renal transplantation, which commonly causes hemolysis, although death or deformities of the graft can also occur in patients with the disorder. Symptomatic supportive treatment is an effective treatment scheme at present, but more effective treatment and prevention schemes still need to be explored.

Passenger lymphocyte syndrome (PLS) is a rare cause of anemia resulting from immune-mediated hemolysis in the post-transplant recipient. We report a case of 26-year-old male who underwent renal transplant. His mother as donor was O positive while he was A positive. He developed anemia at 1-week post-transplant, which later turned out to be PLS. Laboratory findings included rapidly decreasing Hb level and intravascular hemolysis. Hemolysis was brief, because the lymphocytes passed on with the donor organ were able to proliferate only for a while. The case signifies the importance of PLS as a cause for anemia, specifically in the early period after solid organ transplant. It is usually self-limiting, and the treatment requires blood transfusion of donor\'s blood group.

Passenger lymphocyte syndrome (PLS) is a specific subtype of graft versus host disease (GVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) characterized by an immune-mediated hemolysis caused by donor-derived B cells. However, precise nature of PLS has not been well characterized due to its rarity. We herein report two cases of PLS following ABO-incompatible HSCT whose clinical course and dynamics of anti-ABO allo-antibody and blood type conversion were closely examined. Both cases demonstrated acute hemolysis upon engraftment, and the presence of high titer allo-antibody against recipients\' red blood cells (RBCs) helped us to reach the diagnosis of PLS. Hemolysis in both cases showed spontaneous improvement with prednisolone and supportive therapy including transfusion and fluid support. In one case with blood type O, the patient recursively developed PLS in the second and the third HSCT from ABO-mismatch donors, leading to a hypothesis that original blood type O may serve as a background for acute elevation of serum anti-ABO antibody and therefore a risk for developing PLS in multiple ABO-incompatible HSCTs. When hemolysis is noted following ABO-incompatible HSCTs, PLS should be considered and measurement of anti-ABO antibodies is warranted.

Descriptions of passenger lymphocyte syndrome (PLS), immune cytopenias and transplant-associated thrombotic microangiopathy (TA-TMA) after intestine-containing transplants remain scarce. We describe our centre\'s experience of these complications from 2007 to 2019. Ninety-six patients received 103 transplants. PLS occurred in 9 (9%) patients (median 12 days post-transplant); all due to ABO antibodies. There were 31 minor ABO mismatch transplants. No patient required change in immunosuppression. Immune cytopenias (excluding PLS) occurred in six patients at an incidence of 1·7/100 patient years; three immune haemolysis, one immune thrombocytopenia, one acquired Glanzmann\'s and one immune neutropenia; 50% occurred with other cytopenias. All cases eventually responded to treatment, with a median of four treatments (range 1-8) and 5/6 were treated with rituximab. One patient with immune haemolysis required bortezomib. Complications were common in patients with immune cytopenias; 4/6 with infection needing intravenous antibiotics and 3/6 with venous thromboembolism. In 3/6 cases, a secondary cause for the immune cytopenia was evident. Switching from tacrolimus to ciclosporin was not necessary. There were five cases of transplant-associated thrombotic microangiopathy (TA-TMA; 1·5/100 patient years) requiring calcineurin inhibitor withdrawal; two cases associated with acute rejection. Two cases were managed with plasma exchange, one with plasma infusions and one with eculizumab. Further research in this patient group is required.

BACKGROUND: Transplantation-mediated alloimmune thrombocytopenia (TMAT) is a rare complication affecting the recipient of an organ from a donor with immune thrombocytopenia (ITP).
METHODS: We present a case of TMAT following liver transplantation successfully treated by retransplantation, along with a review of previously published cases.Clinical presentation: The liver donor had lupus and ITP and died from an intracranial hemorrhage. The recipient\'s platelet count fell to 2x109/L on postoperative day 2. Due to the lack of response to medical treatment, emergency retransplantation was undertaken with a steady recovery of the platelet count within a few days.
CONCLUSIONS: Six additional cases of transplantation-mediated alloimmune thrombocytopenia after liver transplantation have been reported. In all cases, severe thrombocytopenia ensued within 3 days after liver transplantation. Four patients suffered hemorrhagic complications. Three patients died. Early retransplantation was needed in three out of four patients receiving a graft from a donor with ITP and splenectomy. All recovered shortly after the new graft was in place.
CONCLUSIONS: Severe refractory transplantation-mediated alloimmune thrombocytopenia can develop in liver recipients from donors with ITP, especially those with previous splenectomy. Early retransplantation should be considered if there is no rapid response to medical therapy.