#ExistRefRange>< 1:32 Negative
#ExistInterpData>Titers of 1:32 or higher are considered elevated by this technique. Elevated titers are rarely seen except in primary atypical pneumonia and in certain hemolytic anemias. If the agglutination is not reversible after incubation at 37°C, then the reaction is not due to cold agglutinins.
Primary atypical pneumonia can be caused by Mycoplasma pneumoniae, influenza A, influenza B, parainfluenza, and adenoviruses. However, a fourfold rise in the cold agglutinins usually begins to appear late in the first week or during the second week of the disease and begins to decrease between the fourth and sixth weeks. Low titers of cold agglutinins have been demonstrated in malaria, peripheral vascular disease, and common respiratory disease.