Coldagglutininn (Ca), discovered by Peterson in 1943 from the serum of patients with primary atypical pulmonary pneumonia, is an anti-erythrocyte I antigen IgM antibody. At 56 ° C for 30 min, it remains active. Under the low temperature condition of 0-5 ° C, any blood type of A, B and O can agglutinate with its own red blood cells and O-type and homologous blood cells, which is a non-specific combination. For the diagnosis of pneumonia caused by Mycoplasma pneumoniae. Condensation set testing assists in the diagnosis of pneumonia mycoplasma pneumonia (primary atypical pneumonia). Its cold agglutinin generally begins to increase in the second week after onset.

Basic Information

Specialist classification: Infectious disease inspection and classification: pathogenic microorganism inspection

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:
Serum titers are less than 1:32.

Normal value:

Above normal:
Above normal, it is seen in Mycoplasma pneumoniae infection.

Negative is normal.

Positive can be found in Mycoplasma pneumoniae infection, other such as infectious mononucleosis, severe anemia, malaria, myeloma, mumps, spirochete, ascariasis, trypanosomiasis, staphylococcal sepsis, cirrhosis, etc. can also be positive .

Tips: The disease should be isolated in the family and avoid close contact. Normal value

Serum titer: < 1:32.

Clinical significance

Abnormal results:

When pneumonia or mycoplasma pneumonia, the agglutination price reaches 132 or higher, which may have an auxiliary diagnostic value. Its positive rate is between 50% and 75%. However, hemolytic anemia, cirrhosis, malaria, spirochete, mumps complicated with orchitis, infectious mononucleosis, and acral arterial spasm may also increase, and many of these diseases may be identified by respiratory diseases.

Need to check the crowd: an auxiliary diagnosis of pneumonia.

Positive results may be diseases: adenovirus pneumonia, mycoplasmal pneumonia in the elderly, chronic atrophic limb dermatitis considerations

Inappropriate people: generally no special population.

Contraindications before examination: In the family, attention should be paid to isolation and avoid close contact.

Requirements for inspection: Check with your doctor and follow the doctor's instructions for each step. Especially when the patient is cold or the skin of the limbs is stimulated by cold, hemolysis is prone to occur. Therefore, patients with mycoplasmal pneumonia should pay attention to keep warm.

Inspection process

CA is a high titer of cold lectin produced in serum after examination of human infection with mycoplasma. This lectin can cause agglutination in the cold at 0-4 ° C with red blood cells in the body or red blood cells of "O" type blood. This method is used for the auxiliary diagnosis of primary atypical pneumonia.

Not suitable for the crowd

Those who do not have an indication for examination should not do this check.

Adverse reactions and risks

1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding.

2. Risk of infection: If you use an unclean needle, you may be at risk of infection.