For patients with end-stage renal disease only a kidney transplant is a chance of prolonging and improving their lives. Especially problematic are highly immunized patients who often spend a long time on dialysis while waiting for a deceased donor's transplant.

A patient (f, 53) was listed by Eurotransplant (ET) for 10 years waiting for a kidney transplantation. As requested by ET, the patient was screened quarterly by Luminex HLA antibody screening / identification where strong but constant antibody burden was found. In recent years, the complement‐dependent cytotoxicity assay (CDC) was negative.

In autumn 2023 she had an acute life-threatening closure of the dialysis shunt requiring immediate surgery. She received 3 erythrocyte concentrates intra- and post-operatively. Unfortunately, neither the transplant centre nephrologists nor the HLA lab were informed. 10 weeks after surgery she was offered a deceased donor organ by ET. In the run-up to the transplantation she was routinely interviewed and she told the team of the blood transfusions. A crossmatch against the donor with freshly taken serum was highly positive, while the archived quarterly serum taken a few days before the transfusion was negative. Eventually the kidney was transplanted into another patient. Closer analysis of the crossmatch using the Luminex assay (Labscreen SA1, One Lambda) detected some of the antibodies even in 1:1,000 dilution. Furthermore, a new sample 6 months after the transfusion showed that the antibody profile was not yet back to pre-transfusion levels. In the CDC analysis, both with or without DDT, the PRA was 96% respectively 100%, and no specificities could be defined.

This patient case shows that as few as 3 leukocyte-depleted erythrocyte concentrates can lead to a massive immunisation. Diligence on the part of the regional DSO-HLA lab avoided an impending acute organ failure after transplantation. This case study also highlights first the importance of open communication between all the teams treating a patient on the kidney waiting list, and second the importance of using freshly taken serum if there is a risk of an uncommunicated immunising event.

no conflict of interest