儿童反应性血小板增多症与假性高血清钾症的相关性实验研究

Experimental study on correlation between reactive thrombocythemia and pseudohyperkalemia in children

目的探讨反应性血小板增多症患儿血小板数（PLT）对血清钾测定的影响及临床意义。方法对26例中度反应性血小板增多症（PLT〉400×10^9／L）、36例轻度反应性血小板增多症（PLT300-400×10。／L）、82例血小板数正常（PLT100～300×10^9／L）和21例血小板数减低（PLT〈100×10。／L）患儿，分别用离子选择电极法测定血清和血浆钾，用SYSMEXXS-800i电阻抗全血细胞计数仪检测血小板。结果中度反应性血小板增高症组和轻度反应性血小板增高症组血清钾明显比血小板数正常组和血小板数减低组高（F=11．83，P〈0．01），血清钾分别为（5．05士0．93）mmol／L、（4．66±0．62）mmol／L、（4．26±0．54）mmol／L和（4．28±0．58）mmol／L；而血浆钾4组比较差异却无统计学意义（F=0．27，P〉0．05）。当PLT〉300×10。／L时，血小板数与血清钾呈正相关，血清钾Y（mmol／L）=0．0021x＋3．87（PLT×10^9／L），r=0．78。无论中度反应性血小板增高症组还是轻度反应性血小板增高症组，其血清钾均高于血浆钾（t=2．75～3．02，P〈0．01～O．005），而血小板数正常组及减低组血清钾与血浆钾检测比较，差异均无统计学意义（P〉0．05）。结论反应性血小板增多症患儿血小板数对血清钾测定有正干扰——可因人工分离血清而引起血清钾假性增高；在高血钾症的诊治过程中，应排除假性高血钾症的干扰。

Objective To study the influence and clinical significance of platelet number for determination of serum potassium in children with reactive thrombocythemia. Methods The levels of serum and plasma potassium were measured with ion selective electrode method and the platelets was count by SYSMEX XS-800i electric impedance complete blood counter in 26 moderate reactive thrombocythemia （PLT〉400×10^9/L）,36 mild reactive thrombocythemia （PLT 300--400×10^9/L）, 82 normal platelet number （PLT 100-300×10^9/L） and 21 decreased platelet number （PLT〈100×10^9/L）. Results The study revealed that patients with moderate and mild reactive thrombocythemia had strongly higher concentrations of serum potassium compared to that with normal and decreased platelet groups （analysis of variance [ANOVA], P〈0. 01）, the levels of serum potassium were （5.05 ± 0.93） mmol/L for moderate reactive thrombocythemia, （4. 66 ± 0. 62） mmol/L for mild reactive thrombocythemia, （4. 26 ± 0. 54） mmol/L for normal platelet group and （4.28 ± 0.58） mmol/L for decreased platelet group. However,there was no significant difference of plasma potassium among these four groups （F= 0.27, P〉0.05）. There was a positive correlation between serum potassium and platelet number when PLT〉 300 ×10^9/L, Y（potassium mmol/L） ： 0. 002 1X＋ 3.87 （ ×10^9 platelet/L）, r： 0.78. Not only in group of moderate reactive thrombocythemia,but also in group of mild reactive thrombocythemia,the levels of serum potassium were higher than plasma potassium （t = 2.75-3.02 ,P〈0.01- 0. 005）. However,there was no statistically significant between serum potassium and plasma potassium in normal platelet group as well as decreased platelet group （P〉0.05）. Conclusion The platelet number have a positive interference for detection of serum potassium in children with reactive thrombocythemia. It can result in spurious elevation of serum potassium and that this increment is an artifact. The pseudohyperkalemia must be except in diagnosis and treatment of hyperkalemia.