Lactate dehydrogenase is a glycolytic enzyme. Lactate dehydrogenase is present in the cytoplasm of all tissue cells in the body, with a high kidney content. Lactate dehydrogenase is an enzyme that catalyzes the dehydrogenation of lactic acid to pyruvate, which is present in almost all tissues. There are five forms of isozymes, namely LDH-1 (H4), LDH-2 (H3M), LDH-3 (H2M2), LDH-4 (HM3) and LDH-5 (M4), which can be separated by electrophoresis. . The distribution of LDH isozymes has obvious tissue specificity, so it can be used to diagnose diseases according to their tissue specificity. LDH2 in serum of normal people, >LDH1. If myocardial enzymes are released into the blood, LDH1>LDH2 can be used to diagnose myocardial disease. LDH is almost present in all tissues. The human body has the highest amount of kidneys, and the myocardial, skeletal muscle, liver, and red blood cells are sequentially reduced. Lactate dehydrogenase in effusion is more diagnostic.

Basic Information

Specialist classification: Respiratory examination classification: chest and ascites examination

Applicable gender: whether men and women apply fasting: not fasting

Analysis results:

Below normal:
normal.

Normal value:
Lactic acid dehydrogenase: 0-20U/L

Above normal:
According to the results, cancer or tuberculosis is indicated.

negative:

Positive:

Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. The alcohol content in the blood directly affects the test results. Normal value

Normal value: <20U/L.

Clinical significance

Abnormal result

The LD in the exudate has the highest activity of purulent infection, and the mean value is up to 30 times of the normal serum, followed by the cancerous effusion, and the tuberculous effusion is slightly higher than the normal serum.

In inflammatory or congestive heart failure pleural effusion, LD activity can be similar to serum activity.

The LD activity of cancerous pleural effusion is about 3.5 times that of the patient's own serum LD activity, and the benign effusion is about 2.5 times of its own serum LD activity, which is helpful for differential diagnosis.

Light has proposed LD>200U/L in serous effusion, and effusion LD/serum LD ratio>0.6 can be used as an indicator of exudate.

After the onset of acute myocardial infarction, the activities of LDH1 and LDH2 in the serum increased in the early stage, but the increase of LDH1 was earlier and more obvious, resulting in an increase in the ratio of LDH1/LDH2.

LDH5 is elevated in hepatitis, acute hepatocyte injury, and skeletal muscle injury.

LDH1 can also be elevated in patients with active rheumatic heart disease, acute viral myocarditis, hemolytic anemia, and renal necrosis.

High results may be diseases: hemolytic anemia, malignant pleural effusion, viral myocarditis considerations

Before inspection:

1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results.

2. After 8 pm on the day before the physical examination, fasting should be done to avoid affecting the detection of indicators such as blood glucose in the second sky.

3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection.

When checking:

1. The specimen is not anticoagulated and sent to avoid blood mixing.

2, the linear phase of lactate dehydrogenase reaction is very short, should be measured within 40s after the start of the reaction, must pay attention to this point in the determination of the parameters, otherwise it will lead to errors.

Inspection process

The effusion specimens of various parts of the body are taken and immediately sent for examination, and the detection is detected by immunological or chemiluminescence.

Not suitable for the crowd

Contrained population: The patients who need to be examined include acute myocardial infarction patients, active rheumatic heart disease patients, and pleural effusion patients. Those without examination indications should not be tested.

Adverse reactions and risks

1. Infection: Pay attention to aseptic operation when puncture, pay attention to local cleaning after puncture, prevent water pollution and avoid infection.

2, bleeding: puncture needle damage to local blood vessels or tissue caused by local bleeding, should try to avoid puncture too deep.