How Long can we Store Blood Samples: A Systematic Review and Meta-Analysis

Objective: To assess the effect of storage time and temperature on complete blood count (CBC) and comprehensive metabolic panel (CMP) testing. Methods: PubMed, EMBASE, the Cochrane Library of Systematic Reviews, Web of Science (WOS), China National Knowledge Infrastructure (CNKI), WanFang databases and SinoMed databases were searched up to May 2017. Clinical trials with adult whole blood samples were identified. Paired reviewers independently screened, extracted data and evaluated the quality of evidence (MINORS tool). Analyses were conducted using Revman 5.3 and Stata 14.0. Results: A total of 89 studies were confirmed. For CBC, except MPV, most parameters were stable at least for 24 h. Some indices, such as WBC, PLt, HCT, HGB and MCH were stable up to 3 d. However, stable CMP test results could only be acquired within 12 h. at 4 °C, including GLU, AST, ALT, Na, ALB, Cl, DBIL, TC, TG and ALP. Values were less stable when stored at RT. Conclusions: Specimens stored >12 h. for CMP may generate unreliable results. For CBC, samples could reliably be stored for 24 h. For longer storage, refrigeration (at 4 °C) would be a better choice