Abstract: SA-PO1013

Severe Metabolic Acidosis Secondary to Metastatic Melanoma Reoccurrence: The Warburg Effect

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Barnes, Sylvester, Loyola University, Wheaton, Illinois, United States
  • Bansal, Vinod K., Loyola University Medical Center , Maywood, Illinois, United States
Background

The Warburg effect is a phenomenon where a high rate of glycolysis occurs in tumor cells and it uncoupled from aerobic respiration. To keep up with the metabolic demands of the cell, glycolysis increases at the expense of significant glucose utilization and a resultant elevated lactate levels as oxidative phosphorylation does not occur in this process. It is believed this process allows the cell to export various carbohydrate components from the Krebs Cycle to instead promote cell growth.

Methods

The patient is a 85 year old man with CKD stage 3 who presented to the hospital after being seen by his PCP for increasing dyspnea for 6 weeks. The patient has a history of malignant melanoma first diagnosed in 1964 and no sign of recurrence since 2011. Labs were remarkable for a creatinine of 1.54mg/dl, a serum bicarbonate level of 8mmol/L, albumin of 2.9g/dl, alkaline phosphate 538 IU/L, AST 101 IU/L and ALT of 64 IU/L. His INR and bilirubin were normal. An ABG showed a pH of 7.28, pCO2 of 21mmHg, and calculated bicarb of 9mmol/L. Serum lactic acid was measured at 18 mmol/L. CT scan was obtained showing numerous hypervascular liver lesions, and biopsy confirming melanoma reoccurrence. Nephrology was consulted to help with his metabolic acidosis. When examined the patient was noted to be resting comfortably with only mild tachypnea. Thiamine along with bicarbonate 1300mg three times a day was tried for the patient with no improvement in bicarbonate levels. The patient remained fairly asymptomatic and was discharged home. Four days post discharge the patient presented again to the hospital with increased dyspnea along and altered mental status. Serum bicarbonate was measured at less than 5mmol/L and lactate level obtained was 22mmol/L. An ABG showed a pH of 6.9, pCO2 8mmHg and calculated serum bicarbonate of 2mmol/L. It was decided a focus on comfort would be more appropriate than treatment and the patient ultimately passed away later during the day.

Conclusion

The patient’s persistent lactic acidosis was initially fairly asymptomatic leading to only mild tachypnea and compensatory respiratory alkalosis. It was believed that the majority of his lactate generation was due to his melanoma using primary glycolytic pathways, the Warburg effect. Unfortunately, this is generally seen as a poor prognostic indicator, as was the case for our patient.