JOURNEY OF STOWAWAY PASSENGER: DECODING HEMOLYTIC ANEMIA IN A RENAL TRANSPLANT RECIPIENT

Introduction:

Case Summary 

A 26-year-old gentleman (Blood group B+) with end stage renal disease (ESRD) due to IgA nephropathy, underwent live related renal transplant from his mother (Blood group O+). Pre-transplant evaluation revealed CDC and flow crossmatch was negative. There was no history of blood transfusions or any features suggestive of hemolysis during dialysis. The immunosuppressives given was tacrolimus, mycophenolate mofetil and steroids with no induction in view of low risk rejection transplant.The surgery was uncomplicated and graft function was good (nadir serum creatinine 1.2 mg/dl on POD7)

Methods:

After an uneventful 2 weeks, patient presented with exertional dyspnea and generalized fatigue. Clinical examination revealed pallor, tachypnea, blood pressure of 160/100 mm of Hg (despite four antihypertensives) and rest of systemic examination was unremarkable. Investigations revealed anemia (acute Hb drop from 8.8 to 6 g/dl), leukocytosis and thrombocytosis.There was no obvious history of blood loss. Renal function test showed elevated creatinine and hyperkalemia. Initially, tacrolimus toxicity was suspected, however, tacrolimus level was not high (8 ng/ml). Evaluation showed no evidence of internal blood loss. He was transfused two units of packed cells (Blood group B+). Labs showed reticulocytosis, elevated LDH, indirect hyperbilirubinemia, low haptoglobin, spherocytes and nucleated RBCs on peripheral smear suggestive of intravascular hemolysis. He had received cotrimoxazole for one week as part of pneumocystis jirovecii prophylaxis, hence glucose 6 phosphate dehydrogenase (G6PD) deficiency was suspected, however, levels were high (18.5units). Direct and indirect Coomb’s test performed by tube agglutination method were negative. His hemoglobin continued to drop (Hb 4.8 g/dl) and although hemolysis was evident, there was no apparent cause. Anti B antibodies were looked for in the recipient by tube agglutination technique suspecting ‘passenger lymphocyte syndrome’ (PLS), however, it was not detectable. We had a high index of suspicion, hence acid elution using Glycine HCL was performed on the recipient blood which revealed anti B antibodies, clinching the diagnosis of PLS. He was then managed with O positive blood group transfusions, pulse dose steroids and rituximab (100mg), after which his hemoglobin levels stabilized. G6PD levels repeated after 3 months were normal.

Results:

Discussion:With the unveiling of positive Anti-B antibodies by elution technique, PLS stemming from minor mismatch in recipient (blood group O to B) was confirmed. These alloantibodies were produced by the donor B lymphocyte passengers, which reached the recipient through the graft, mounting a graft vs host response.

Conclusions:

Conclusion:A high index of suspicion for PLS is warranted in evaluating unexplained hemolysis in the immediate post-transplant period. Our case report highlights the need for testing anti ABO antibodies via acid elution technique in case PLS is suspected even if tube agglutination is negative.

Pictorial representation of our case

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.