Department of Vascular Diseases, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Clin Chem Lab Med. 2010 Oct;48(10):1463-5. doi: 10.1515/CCLM.2010.285. Epub 2010 Jul 11.
Although light transmittance aggregometry is considered the gold standard for platelet function testing, it is poorly standardized. The effect of several pre-analytical variables on this assay was investigated.
Light transmittance aggregometry was performed with an automated coagulation analyzer using arachidonic acid (1.6 mmol/L), adenosine-5-diphosphate (ADP) (11 μmol/L) and collagen (11 mg/L, all final concentrations). The results were reported as maximum aggregation (in %) in 10 min. Twenty apparently healthy subjects were tested three times on two consecutive days: on day 1, fasting samples were collected in the morning and mid-day; on day 2, samples were collected in the morning after a light breakfast. Light transmittance aggregometry was performed immediately after preparation of platelet-rich-plasma (PRP), after stabilization (30 min) of non-adjusted and platelet count (225-275×10(9)/L) adjusted PRP, and at 2 and 4 h after blood collection.
Maximum aggregation was higher in the non-adjusted compared to the adjusted PRP with all three agonists used (all p<0.05). Arachidonic acid and ADP, but not collagen, induced maximal aggregation was significantly decreased after 4 h (arachidonic acid from 84%, 73%-90% to 71%, 28%-85%, p<0.001; ADP from 79%, 62%-87% to 66%, 50%-79%, p<0.001, medians with inter-quartile ranges). Short-term stabilization of PRP, consumption of breakfast and sampling at mid-day had no significant effect on maximal aggregation.
Blood collection and plasma preparation can be simplified by omitting short-term stabilization of PRP and adjustment for platelet count. The subjects can be tested from morning to mid-day, and a light breakfast is acceptable. However, the analyses should not be postponed for more than 2 h if arachidonic acid or ADP are used as agonists.
尽管光传输聚集测定被认为是血小板功能检测的金标准，但它的标准化程度较差。本研究考察了几种分析前变量对该检测的影响。
使用自动化凝血分析仪，采用花生四烯酸（1.6mmol/L）、二磷酸腺苷（ADP）（11μmol/L）和胶原（11mg/L，均为终浓度）进行光传输聚集测定。结果以 10 分钟时的最大聚集率（%）表示。20 名健康志愿者连续两天分 3 次进行检测：第 1 天，分别于早晨和中午空腹采集样本；第 2 天，在轻早餐后于早晨采集样本。在制备富含血小板血浆（PRP）后、非调整和血小板计数（225-275×10(9)/L）调整 PRP 稳定（30 分钟）后以及采血后 2 小时和 4 小时立即进行光传输聚集测定。
与调整后的 PRP 相比，使用所有三种激动剂时，未经调整的 PRP 诱导的最大聚集率更高（所有 p<0.05）。ADP 和花生四烯酸诱导的最大聚集率在 4 小时后显著降低（花生四烯酸从 84%、73%-90%降至 71%、28%-85%，p<0.001；ADP 从 79%、62%-87%降至 66%、50%-79%，p<0.001，中位数，四分位间距）。PRP 的短期稳定、进餐和中午采样对最大聚集率没有显著影响。
如果使用花生四烯酸或 ADP 作为激动剂，省略 PRP 的短期稳定和血小板计数的调整可以简化血液采集和血浆制备。可以从早晨到中午对受试者进行检测，并且可以接受轻早餐。但是，如果使用花生四烯酸或 ADP 作为激动剂，分析不应推迟超过 2 小时。
