hypertension
Hypertension, also known as elevated blood pressure, is a phenomenon in which the pressure on the walls of blood vessels is persistently higher than normal as blood flows through the blood vessels. Hypertension is often referred to as the "silent killer", most patients can develop the disease without any symptoms, and the prolonged higher-than-normal pressure on the blood vessel wall can lead to coronary heart disease, stroke and other severe diseases.
Epidemiology shows that the latest data from the China Hypertension Survey show that the prevalence of hypertension in mainland China from 2012 to 2015 was 27.9%, which means that about 1 in 3 adults has hypertension, and the prevalence trend is gradually increasing.
The latest survey also found that for the first time, the prevalence of hypertension in rural areas surpassed that in urban areas; the prevalence of hypertension in Tibetan, Manchu, and Mongolian populations was higher than that of Han Chinese; and the prevalence of hypertension showed an increasing trend from the south to the north.
Secondary hypertension
Secondary hypertension, also known as symptomatic hypertension, is an elevated blood pressure due to some identified disease or etiology. When the primary disease is cured, the high blood pressure that is a secondary symptom also declines or returns to normal. Therefore, early identification of the cause and timely treatment have a promoting effect on the cure and outcome of the disease.
The proportion of patients with secondary hypertension is about 5-10% of all hypertensive patients, and although the proportion is not high, the absolute number is still quite large.
Secondary hypertension is easily misdiagnosed as hypertension, but with the in-depth understanding of the disease and the advancement of diagnosis and treatment technology, the detection rate of secondary hypertension has increased significantly, and the control rate of the cause has also improved.
Pheochromocytoma (PCC) and paraganglioma (PGL) are common causes of secondary hypertension
PCC originates from the adrenal medulla, PGL is a neuroendocrine tumor that originates from the sympathetic chain outside the adrenal glands and has hormone secretion function, mainly synthesizing, secreting and releasing a large number of catecholamines (CA), such as epinephrine (E), norepinephrine (NE), dopamine (DA), causing a series of clinical symptoms such as increased blood pressure and metabolic changes in patients, and causing serious complications such as heart, brain, kidney, and blood vessels, and even becoming the main cause of death in patients.
PCC tumors are located in the adrenal glands, and PGL tumors are located in the parapinal sympathetic chains of the chest, abdomen, and pelvic cavity, which are collectively called PPGL.
PPGL is one of the causes of secondary hypertension, and its prevalence has been on the rise in recent years!
Catecholamines are a key indicator in the diagnosis of pheochromocytoma (PCC) and paraganglioma (PGL).
Clinical significance of detection of catecholamines and their metabolites
PPGL synthesizes and secretes large amounts of catecholamines, so its diagnosis depends primarily on the determination of catecholamines and their metabolites. These include catecholamine prototypes epinephrine (E), norepinephrine (NE) and dopamine (DA); intermediate metabolites methoxyephrine (MN) and methoxydeephrinephrine (NMN), both collectively referred to as MNs.
MNS can be formed in pheochromocytes or pheochromocyte-derived tumors via catechol-methoxytransferase (COMT), which is deficient in the sympathetic nerves of the initial norepinephrine metabolism, so MNNs are specific markers for PPGL.
The half-life of MNs is longer than that of catecholamines, more stable, can directly reflect the state of pheochromoma cells, and MNs are specific and sensitive, so MNs have become the recommended markers in the guidelines for the diagnosis and treatment of pheochromocytoma.
Catecholamines include epinephrine (E), norepinephrine (NE), and dopamine (DA), commonly known as catecholamine prototypes, which are neurotransmitters or hormones present in the center and peripherals. These neurotransmitters are involved in a variety of regulatory systems and metabolic processes and serve as important biomarkers for the screening, diagnosis, treatment, and prognosis of a wide range of neuroendocrine and cardiovascular diseases.
Catecholamine metabolites mainly include methoxyephrine (MN), methoxy norepinephrine (NMN), which, when measured in combination with catecholamine prototypes, can provide personalized information on disease development and therapeutic effects.
Catecholamines and their metabolites have low concentrations, pg/ml level, high sensitivity requirements for the instrument, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become the mainstream method for the detection of catecholamines and their metabolites because of its high selectivity and sensitivity.
Expert Consensus on the Diagnosis and Treatment of Pheochromocytoma and Paraganglioma (2020 Edition)
Five tests of serum catecholamines are recommended by mass spectrometry, which are the first specific markers recommended for PPGL diagnosis
Expert Consensus on the Diagnosis and Treatment of Pheochromocytoma and Paraganglioma (2020 Edition): With the rapid development of mass spectrometry technology, liquid chromatography tandem mass spectrometry (LC-MS/MS) has become the main method for detecting catecholamines and metabolites because of its high sensitivity, strong specificity, and rapid screening of a large number of samples.
Catecholamine detection advantages
Advantage 1: The first magnetic bead method, a single specimen can produce results in 45 minutes at the fastest, and the operation is easier
Clinically, blood and other samples cannot be directly sent to mass spectrometry for analysis, and must go through a series of sample pretreatment processes (such as magnetic solid phase extraction, solid phase extraction, etc.) to achieve the purpose of reducing matrix interference and improving sensitivity and accuracy.
At present, most laboratories complete the sampling and sampling steps of SPE by manual operation, which requires high skills of clinical operators and is prone to human error. At present, some manufacturers have issued the use of magnetic bead method (MGE) for sample pretreatment detection method, magnetic bead method sample pretreatment process is simple, greatly saving manpower and time costs, and is expected to develop LC-MS/MS technology into a fully automatic analyzer integrating pretreatment and detection, which is greatly valued by clinical testers.
In order to improve the efficiency of laboratory work, improve the experimental environment and data quality, the MS-M32 automatic extraction instrument launched by Meikang Bio adopts a new generation of sample extraction technology, equipped with magnetic separation materials, using magnetic rods to absorb and separate materials, activation, dosing, leaching, elution and other separation processes to achieve full automation, easily realize sample extraction and purification before chromatography or mass spectrometry analysis. It is used for rapid extraction of clinical small molecule markers such as catecholamines and steroid hormones.
Advantageous features
1. The first magnetic bead method, the fastest single specimen out of the results in 45 minutes, the operation is more simple, 32 samples only need 16 minutes;
2. Compared with traditional SPE technology, the extraction efficiency is increased by more than 6 times;
3. Simplify the complex, a new generation of extraction technology, dedicated to the extraction of small molecule substances;
4. Dispersed filling, dynamic balance, no blockage, good stability and consistency;
5. Magnetic, very suitable for automation, only a few steps to complete the extraction and purification steps;
6. Provide multiple separation mechanism, suitable for the extraction and purification of complex samples, and further reduce the requirements for the sensitivity of analytical instruments.
Fields of application
Advantage two: the second type of registration certificate, the test is more standardized
Meikang's first magnetic bead catecholamine detection kit (LC-MS/MS)
Detection analysis
1. Short analysis time (4min/test);
2. No interference, isomers can be separated;
3. The sample dosage is small;
4. Simultaneous detection of 5 blood catecholamines ("Expert Consensus on the Diagnosis and Treatment of Pheochromocytoma and Paraganglioma (2020 Edition)" pointed out that 5 blood catecholamines were the first specific markers recommended for PPGL diagnosis. ）
Catecholamine detection kit
Meikang MS-S900 mass spectrometer catecholamine detection diagram
Advantage three: traceable to SI units, the results are more accurate
Meikang Reference Laboratory
Meikang Reference Laboratory is established in strict accordance with ISO 17025 & ISO 15195 standards, running more than 40 reference measurement procedures such as vitamins and steroid hormones.
As of March 2022, 24 projects in the reference laboratory have been accredited by CNAS; 15 projects have entered the JCTLM reference measurement service list. In cooperation with the Chinese Academy of Metrology and the China Institute of Food and Drug Control, it has participated in the development and joint valuation of international/national reference materials for more than 30 projects such as 25-hydroxyvitamin D, testosterone, aldosterone, immunosuppressants, etc., providing a strong guarantee for the standardization of clinical test results.
ISO 17025 & ISO 15195 Medical Reference Laboratory Accreditation
The clinical tandem mass spectrometry technology platform is different from the traditional field of analytical chemistry in that it must not only meet the needs of substance-specific detection, but also meet the requirements of accuracy, repeatability and linearity of clinical testing.
As the overall solution for catecholamine mass spectrometry detection, the magnetic bead pretreatment system solves the problem of cumbersome, time-consuming and laborious pretreatment procedures for sample pretreatment of mass spectrometry testing projects, and provides a convenient way for clinical testing!
【Reference】
Liu Xiaogang,Hu Liqun. Talking about secondary hypertension[J].Family Medicine,2021,(9):4-5.
Endocrinology Branch of Chinese Medical Association. Expert Consensus on the Diagnosis and Treatment of Pheochromocytoma and Paraganglioma (2020 Edition)[J].Chinese Journal of Endocrine Metabolism,2020,36(9):737-750.
Liu Qingxiang,Zhou Weiyan,Zhang Chuanbao. Detection status and standardization expectations of catecholamines and their metabolites[J].Chinese Journal of Laboratory Medicine,2020,43(3):322-327.
Zhao Ruixue,Wang Shu,Jing Lu,Wang Xian. Based on the new version of hypertension guidelines at home and abroad, the problems and thoughts of pre-hypertension are discussed[J].Journal of Practical Cardiovascular and Cerebrovascular Diseases,2022,30(1):1-5.
Edited by: Yeah Reviewer: Xiao Ran