These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Long-term stability of endogenous B-type natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) in frozen plasma samples. Author: Mueller T, Gegenhuber A, Dieplinger B, Poelz W, Haltmayer M. Journal: Clin Chem Lab Med; 2004; 42(8):942-4. PubMed ID: 15387447. Abstract: The aim of the present study was to assess the long-term stability of endogenous B-type natriuretic peptide (BNP) and amino terminal proBNP (NT-proBNP) in plasma samples stored at -20 degrees C without addition of protease inhibitors (e.g., aprotinin). Stability of BNP and NT-proBNP was tested in 60 EDTA plasma samples with BNP values between 30 and 420 pg/ml. Initial BNP and NT-proBNP plasma concentrations were determined within four hours after blood collection using the AxSYM BNP and the Elecsys NT-proBNP assays. Subsequently, all samples were stored at -20 degrees C and were thawed for the second BNP and NT-proBNP determination on the two instruments after one day, 30 days, 60 days, 90 days and 120 days, respectively. Mean recovery (i.e., residual immunoreactivity) of BNP and NT-proBNP expressed in percent of the initial value for the given time interval of storage was calculated. Mean recovery of BNP was less than 70% after one day of storage at -20 degrees C and decreased to less than 50% after two to four months of storage (e.g., recovery of endogenous BNP after three months of storage at -20 degrees C ranging from 0% to 71%). In contrast, mean recovery of NT-proBNP was generally greater than 90%, irrespective of the duration of storage at -20 degrees C (e.g., recovery of endogenous NT-proBNP after three months of storage at -20 degrees C ranging from 91% to 112%). In conclusion, the determination of endogenous BNP with the AxSYM assay using frozen plasma samples may not be valid under the conditions tested. In contrast, NT-proBNP as measured by the Elecsys assay may be stored at -20 degrees C for at least four months without a relevant loss of the immunoreactive analyte.[Abstract] [Full Text] [Related] [New Search]