Pseudohyperkalemia in chronic lymphocytic leukemia: Prevalence, impact, and management challenges

The term pseudohyperkalemia refers to a false elevation in serum potassium levels due to potassium release from cells in vitro. Falsely elevated potassium levels have been reported in patients with thrombocytosis, leukocytosis, and hematologic malignancies. This phenomenon has been particularly described in chronic lymphocytic leukemia (CLL). Leukocyte fragility, extremely high leukocyte counts, mechanical stress, higher cell membrane permeability related to an interaction with lithium heparin in plasma blood samples, and metabolite depletion due to a high leukocyte burden have been reported to contribute to pseudohyperkalemia in CLL. The prevalence of pseudohyperkalemia is up to 40%, particularly in the presence of a high leukocyte count (>50 x 10(9)/L). The diagnosis of pseudohyperkalemia is often overlooked, which may result in unnecessary and potentially harmful treatment. The use of whole blood testing and point-of-care blood gas analysis, along with thorough clinical evaluation, may help differentiate between true and pseudohyperkalemic episodes.

Automated summary

Pseudohyperkalemia refers to falsely elevated serum potassium levels due to in vitro potassium release from cells. It has been reported in patients with thrombocytosis, leukocytosis, and hematologic malignancies, particularly chronic lymphocytic leukemia (CLL). Various factors contribute to pseudohyperkalemia in CLL, including leukocyte fragility, high leukocyte counts, mechanical stress, higher cell membrane permeability, and metabolite depletion. The prevalence of pseudohyperkalemia is up to 40%, especially in cases with high leukocyte count (>50 x 10(9)/L). The diagnosis of pseudohyperkalemia is often missed, leading to unnecessary and potentially harmful treatment. Whole blood testing and point-of-care blood gas analysis, combined with thorough clinical evaluation, can help differentiate between true and pseudohyperkalemic episodes.