MO195ATYPICAL HEMOLYTIC UREMIC SYNDROME IN LUNG TRANSPLANTATION: TREATMENT WITH ECULIZUMAB, OUR EXPERIENCE

Background and Aims Atypical haemolytic uremic syndrome (aHUS) is a clinical entity characterized by acute kidney injury, thrombocytopenia and microangiopathic hemolytic anemia. There are several cases of AHUS in non-renal solid organ transplants described in the literature, included lung transplant. Kidney and patient survival are compromised by this complication because of the lack of an effective treatment. Eculizumab is C5 complement factor specific blocker already administered in another kind of secondary aHUS with encouraging results Method We analys six lung transplants in a retrospective single-center study between 2018-2020 who developed an aHUS and were treated with eculizumab. Clinical and analytical data were collected along the follow-up. Principal outcome was to explore haematologycal and renal response after treatment with eculizumab. Results We included a total of six patients (83% were female) with a median age of 57 years at the time of transplantation. Aetiologies of lung transplantation were chronic obstructive pulmonary disease in 2 patients, interstitial lung disease in another 2, and cystic fibrosis in the remaining two. Induction and maintenance immunosuppressive therapy were based on tacrolimus, mycophenolate and prednisone in all cases. Baseline serum creatinine after lung transplantation was 1.1 mg/dl (0.9-2.4). Two patients developed an aHUS in the immediate post-transplant, one of them died because of surgical complications. Another four patients developed an aHUS 59 months (33-95) after transplantation. Previously of thrombotic microangiopathy, three patients were on treatment with everolimus instead of mycophenolate and two lung transplants have cytomegalovirus reactivation. At the aHUS onset, median serum creatinine was 4mg/dl (2.4-5-7) and acute dialysis was performed in 50% of patients. Median hemoglobin was 7.2g/dl (6.9-7.7), platelet count was 32x1000/µL (17-58), and DHL was 1343 U/L (581-1597) at the start of eculizumab despite having treated the trigger. After a median of 6 doses of eculizumab, the five surviving patients had haematologycal and renal response. No patients underwent chronic dialysis. Serum creatinine was 2.2 mg/dl (1.7-2.3), hemoglobin 9.8 g/dl and platelet count 159x1000/µL at the end of follow-up. Conclusion AHUS is a critical complication in lung transplantation, shortly related with immunosuppressive therapy. Patients are at risk of end stage renal disease. Eculizumab treatment appears promising.