Leach et al reviewed the features distinguishing a clinically significant cold agglutinin from one that is primarily a laboratory phenomenon.
Clinically significant cold agglutinins may be identified in patients with:
(1) cold agglutinin disease
(2) lymphoproliferative disorders
(3) mycoplasma pneumonia
Finding |
Insignificant |
Significant |
in vivo hemolysis |
absent |
present |
bind complement |
no |
yes |
agglutination |
reversible |
irreversible |
thermal range |
narrow (0 to 6°C) |
wide (4 to 32°C) |
maximum activity at 0 to 4°C |
yes |
no |
active at room temperature (20°C) in saline |
no |
yes |
agglutination at 30°C after incubation with albumin |
not enhanced |
enhanced |
Significant cold agglutinins are usually IgM, while insignificant ones are usually not.
The Donath-Landsteiner antibody is a clinically significant cold agglutinin with features that differ in some of the features listed in the table above.
Specialty: Immunology/Rheumatology