The Yellow Dialyzer Sign: An Unassuming Indicator of Occult Jaundice in Patients with End-stage Kidney Disease. A Case Report.

In patients with end-stage renal disease (ESRD), diagnosing jaundice can be challenging because uremic skin changes and anuria may obscure classic signs such as scleral icterus and dark urine. We report a rare case in which discoloration of the hemodialysis circuit provided the first clue to occult hyperbilirubinemia. A 35-year-old woman with ESRD secondary to lupus nephritis presented for hemodialysis with features of uremia and fluid overload. Physical examination revealed no scleral icterus or skin discoloration. After a 2-hour session using a low-flux polysulfone dialyzer, a striking yellowish discoloration of the dialyzer membrane was noted. Laboratory evaluation, prompted by this observation, revealed marked unconjugated hyperbilirubinemia, elevated lactate dehydrogenase, low haptoglobin, and hemoglobinuria, confirming intravascular hemolysis complicating systemic lupus erythematosus. The yellow discoloration was attributed to the adsorption of bilirubin-albumin complexes onto the hollow fibers of the dialyzer membrane. The patient was treated with high-dose oral prednisolone for autoimmune hemolytic anemia associated with a lupus flare. Over three weeks and six subsequent dialysis sessions, hemolysis markers normalized, the yellow discoloration resolved, and her clinical condition improved significantly. Yellowish staining of the dialyzer membrane is an uncommon but important bedside sign of hyperbilirubinemia in patients undergoing dialysis. This extracorporeal indicator may reveal serious conditions such as intravascular hemolysis or hepatic dysfunction when conventional clinical signs are absent. Careful inspection of the dialysis circuit can facilitate early diagnosis, prompt treatment, and improved outcomes in this vulnerable population.