StatusThe thesis was presented on the 5 March, 2009
Approved by NCAA on the 23 April, 2009
Abstract– 0.42 Mb / in romanian
ThesisCZU 616.127-005.8-074: 546.41+543.9:546.41
0.73 Mb /
While the given study is dedicated to the immunoenzymatic diagnosis of AMI, the author developped a diagnostic test using SR Ca2+-ATP-ase as a biological marker of AMI. The intent started from the assertion that SR Ca2+-ATP-ase, being integral part of the SR membrane, during myocardial necrosis is sequestrated in blood, where it may be detected by means of a specific immunoenzymatic assay.
The ELISA method, which is based on using specific monoclonal antibodies, was preffered for the implementation of the diagnostic procedure for determination SR Ca2+-ATP-ase. Having on hand canine SR vesicles enriched in Ca2+-ATP-ase pump, previously purified by S.Sârbu (1986) and using the classical method of hybridization (animal immunization with canine SR Ca2+-ATP-ase, fusion of lymphocytes producing specific antibodies with myeloma cells), we have developed specific monoclonal antibodies to SR Ca2+-ATP-ase (of two classes - IgM and IgG).
To validate SR Ca2+-ATP-ase as a biological marker in the diagnosis of AMI, we have examined 56 patients with AMI, confirmed by elevated levels of biological markers for myocardial necrosis (troponin and CPK-MB). The presence of SR Ca2+-ATP-ase in the serum of patients with AMI was assessed by means of both quantitative and qualitative procedures. Elevation of SR Ca2+-ATP-ase was noticed in all patients included in the study: it appears at approximately 4-6 hours after the event and disappears after 144 hours (6 days). The same patients were tested for the recommended markers of myocardial necrosis - CPK-MB and troponin (qualitative test), allowing for a precise correlation of elevated CPK-MB levels with elevated SR Ca2+-ATP-ase.
Analyzing the specificity and sensitivity of the newly developed assay system, we have observed that SR Ca2+-ATP-ase appears only in necrotic changes of cardiomyocytes, unlike troponin or CPK-MB, which may be elevated in other muscles’ abnormalities. Additionally, the titre of SR Ca2+-ATP-ase correlates with the extent and volume of affected myocardium, with ST segment denivellation and the presence of major cardiovascular risk factors.
The diagnostic specificity for AMI of the newly developped test system is supported by the fact that SR Ca2+-ATP-ase was not detected in the control groups composed of patients with acute muscular trauma and patients on haemodialysis. In addition, the SR Ca2+-ATP-ase also was non-detectable in the sera of patients with ACS (20 patients). In summary, we demonstrated that SR Ca2+-ATP-ase is a new biological marker of myocardial injury and determination of Ca2+-ATP-ase in serum samples may be used in diagnosis of AMI.