Lysozyme is a component of the normal immune defense mechanism and has the function of dissolving bacterial cell walls. In the human body, it is present in neutrophils, monocytes and macrophages; it is also present in mucosal secretions and is one of the surface defense factors. Normal people have no lysozyme in their urine. The lysozyme activity values ​​in serum or body fluids of some patients have significant differences, so the determination of lysozyme activity has received increasing clinical attention. Common methods are agar plate method and turbidimetry.

Basic Information

Specialist classification: Respiratory examination classification: chest and ascites examination

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

Tips: Before the test, the subject stops taking the drug and minimizes the movement to ensure the quality of the test. Normal value

1, serum 5 ~ 30mg / L (agar plate method); 9.6 ~ 14mg / L (turbidimetric assay).

2, cerebrospinal fluid 0mg / L (agar plate method).

3, saliva 30 ~ 70mg / L (turbidimetric assay).

4. Urine 0 mg/L (agar plate method); 1 to 3 mg/L (turbidimetric assay).

Clinical significance

Abnormal result

It is important for differential diagnosis of malignant and tuberculous pleural effusion. 94% of tuberculous effusion Lzm content exceeds 30mg/L, and P-Lzm/S-Lzm (pleural effusion Lzm/serum Lzm) ratio >1 is significantly higher than cancerous product. Fluid, connective tissue disease. Simultaneous determination of Lzm and LD in pleural effusion, both tuberculosis increased, leakage caused by heart failure is low, Lzm is low and LD activity is high in cancerous pleural effusion, this separation is cancerous Characteristics of pleural effusion.

Low results may be diseases: high pleural effusion results may be disease: tuberculosis, chronic bronchitis considerations

Before the test: The subject stopped taking the drug and minimized the movement to ensure the quality of the test.

When checking: Relax your body and listen to your doctor's instructions.

Not suitable for the crowd: no.

Inspection process

The puncture is taken immediately after the effusion specimen is taken. Detection method:

1. Preparation of a cell wall of Micrococcus. The M. solani was subcultured on agar slant medium before use, and then cultured on a common agar plate at 37 ° C for 24 h. The lawn was washed with sterile distilled water, centrifuged at 2000 r/min for 30 min, and the supernatant was discarded. Add distilled water and mix gently, centrifuge at 2000r/min for 30min, discard the supernatant, weigh the wet weight of the sediment, and prepare 100g/L concentrated bacteria solution with sterile distilled water. The bacteria solution should be prepared before use. It should not be stored. Long), heat killed, spare.

2. Weigh 1g of agar powder, add 100ml of 1/15mol/L pH6.4PBS, and add 1% agar.

3. Take the lysozyme standard and make 5, 25, 100 mg/L dilution solution with 1/15 mol/L pH PBS.

4. Take 1 ml of the prepared bacterial solution, add it to 50% to 60 ° C dissolved 1% agar, shake well, pour the plate (diameter 7 ~ 9cm plate plus 1% agar 15ml), to be condensed.

5. Punch holes in the microspheres agar plates with a puncher, the hole spacing is 18 ~ 20mm, pick up the agar in the hole with a toothpick.

6. Use a capillary pipette to take saliva (freshly collected, in a clean dish, take the supernatant) or serum, and add to the agar hole. At the same time, another well was filled with standard lysozyme as a positive control.

7. Set 25 to 30 ° C for 18 to 24 hours and observe the results.

8. At the same time of each batch of measurement, add various concentrations of lysozyme standard solution to the small holes, measure the diameter of the lysate ring by the same method, use semi-logarithmic paper, and use the lysozyme concentration as the ordinate (logarithmic coordinate) to dissolve the bacteria. The ring diameter is the abscissa and a standard curve is drawn. The micrograms of lysozyme contained per ml of the test article were found from the curve.

Not suitable for the crowd

Contrained people: people who need to be tested have leukemia patients, kidney damage, meningitis and so on. 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.