Fukasawa H, Furuya R, Kato A, Yonemura K, Fujigaki Y, Yamamoto T, Hishida A
First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Clin Nephrol. 2002 Dec;58(6):451-4. doi: 10.5414/cnp58451.
Pseudohyperkalemia is defined as a serum potassium concentration 0.4 mEq/l greater than the plasma concentration. The basis of this phenomenon is the release of intracellular potassium from platelets, leukocytes, or erythrocytes, commonly in the setting of extreme leukocytosis (> 10 x 10(4)/microl) or thrombocytosis (> 60 x 10(4)/microl). We report a case of pseudohyperkalemia in a patient with chronic renal failure and polycythemia vera without the finding of severe leukocytosis or thrombocytosis (white blood cell count 1.88 x 10(4)/microl and platelet count 37.9 x 10(4)/microl, respectively). The serum potassium concentration was 8.2 mEq/l, while the plasma potassium level was 6.4 mEq/l in a sample obtained simultaneously. The concentrations of platelet factor IV and beta-thromboglobulin, known to be markers of platelet activation, were greater than 100 ng/ml and 200 ng/ml, respectively, indicating that platelet activation may have been related to the development of pseudohyperkalemia in this patient. These findings suggest that pseudohyperkalemia should be considered when hyperkalemia is seen in a patient with chronic renal failure and myeloproliferative disorders.
假性高钾血症定义为血清钾浓度比血浆浓度高0.4 mEq/l。这种现象的基础是血小板、白细胞或红细胞释放细胞内钾，通常发生在极度白细胞增多（>10×10⁴/微升）或血小板增多（>60×10⁴/微升）的情况下。我们报告一例慢性肾衰竭和真性红细胞增多症患者出现假性高钾血症的病例，该患者未发现严重白细胞增多或血小板增多（白细胞计数分别为1.88×10⁴/微升和血小板计数为37.9×10⁴/微升）。同时采集的样本中，血清钾浓度为8.2 mEq/l，而血浆钾水平为6.4 mEq/l。已知血小板活化标志物血小板因子IV和β-血小板球蛋白的浓度分别大于100 ng/ml和200 ng/ml，表明血小板活化可能与该患者假性高钾血症的发生有关。这些发现提示，在慢性肾衰竭和骨髓增殖性疾病患者出现高钾血症时应考虑假性高钾血症。
