The lipid standardization program (LSP) controls have been produced by Solomon Park Research Laboratories since 1995 using a procedure (the CLSI C37-A) that ensures commutability of testing for lipids to the serum in these materials. These materials are further distinguished by having the analytes of interest, in this case lipids and more recently lipoproteins, measured by certified reference procedures through the CDC itself or from the network of reference laboratories monitored by this agency. The story of the LSP and Solomon Park’s participation in this singular effort is summarized here.
The LSP was initiated in 1961 by the Communicable Disease Center (CDC) later to become the Centers for Disease Control and Prevention (still abbreviated CDC) in response to a number of research and epidemiological studies carried out in the 1940s and 1950s that had provided preliminary but growing evidence that there was a relationship between cholesterol and heart disease. Before this time, research on the correlation between cholesterol and heart disease had been sporadic and there had not been any concerted long-term attempts to prove this relationship. The all too prevalent opinion within the medical community was that heart disease was simply an inevitable consequence of age with some life choices such as alcohol and tobacco use and obesity or stress causing most preliminary disease or death incidents from cardiovascular events.
With an increasing number of centers measuring cholesterol associated with these newer efforts, however, came some practical problems; not the least of which was that when these laboratories exchanged patient specimens there was a wide range of values assigned to the same samples when cholesterol was measured and compared using the various procedures.
It became obvious that in order to reasonably make judgments related to the research and long term studies, such as the now world famous Framingham Heart Study begun in 1948, that two technical advances needed to take place: 1) the measurement of cholesterol needed to be done by a single agreed upon method and 2) that this method needed to be monitored using a centralized and neutral source of controls. The first Cholesterol Standardization Program began in 1958 with seven epidemiologic laboratories. Out of this effort the Abell-Kendall method was chosen as the test of choice and was eventually to become the reference method for cholesterol testing.
In these early efforts, the calibrators used to monitor the laboratories were lyophilized samples prepared by the CDC. Eventually, however, it would become evident that lyophilization caused unacceptable changes in the matrix within which the lipids and lipoproteins carrying cholesterol were presented to the measurement processes. In order to address this problem, in the 1990s the CDC and several other agencies researched and developed a procedure for serum controls for the LSP that utilized frozen human serum reference materials that are prepared by using a protocol that results in frozen and, most importantly, commutable serum pools that behaved very similarly to freshly drawn patient samples (the Clinical Laboratory Standards Institute’s C37-A procedure cited earlier). Solomon Park Research Laboratories participated in and was selected at that time to prepare these materials and has done so continuously for the past 24 years.
From the inception of the LSP, the funding had been provided by the National Heart Lung and Blood Institute (NHLBI) and the CDC, the full and proper name for the program being the CDC-NHLBI LSP. In October, 2008, at the beginning of the most recent recession in the United States, the NHLBI ended support for this program. As a result of this loss of funding, participants have been, for the first time since its inception, required to pay for the materials and to provide additional funds for shipping to receive these materials. It was feared that these charges might affect the number of enrolled institutions. The impact, however, now eleven years later, has been minimal on the number of participating laboratories. The immense value of the LSP could have no better proof of its worth to the scientific and medical communities.
Laboratories or other facilities interested in becoming participants in the LSP should contact the CDC at [email protected] for instructions in being considered for the program.