Table 3.

Procedure for bedside cold agglutination test

1. Draw patient’s blood into a tube containing anticoagulant (e.g., citrate; standard tubes for determination of prothrombin activity can be used)

2. Cool in ice water for 30 s to 5 min

3. Tilt tube on the side and examine for coarse agglutination of red cells on the tube wall

4. The test is positive if agglutination occurs

5. Rewarming should redissolve the agglutination, recooling should reproduce it

6. The strength of the agglutination correlates with the severity of the M. pneumoniae pneumonia

Adapted from (3,10).