A Donath Landsteiner test is a blood test that is commonly used to detect harmful antibodies that are related to a relatively rare disorder known as paroxysmal cold hemoglobinuria. This condition is considered to be the first type of autoimmune hemolytic anemia that was identified. The test attained its name as a result of the fact that Juilius Donath and Karl Landsteiner were the first to discover a unique biphasic hemolysin in the blood. In cold conditions, this antibody will tend to attach itself to the blood and induces hemolysis, hence the red blood cells are warmed as a result of environmental factors or as a result of the body going through a phase of heightened physical activity. In a study conducted on children it was found that 40% of all immune hemolytic anemias were the result of the Donath Landsteiner antibody.
The condition is not necessarily one that requires a significant amount of treatment, as when treated quickly and with the right care, it could be easily taken care of within a stretch of a few days to a couple of weeks. Fatality is an extremely rare scenario and is only attributed to the most severe variants of the condition. Moreover, men tend to be more commonly affected by the condition than when compared to women at a ratio of about 5:1. The condition exists in both - acute and chronic versions. The chronic type affects mostly young children and will usually follow an acute viral or upper respiratory tract infection while the chronic version is commonly seen in the elderly.
The Donath Landsteiner test is performed by drawing a sample of blood from the vein of the patients arm. An elastic band or pressure cuff may also be placed around the upper portion of the arm in order to apply pressure as well as restrict any blood flowing through the vein - causing the vein to swell with blood. A needle will then be inserted into the vein. The blood will then be collected in an air tight syringe, before the band on the upper arm is removed to resume normal blood flow. When infants or younger children are tested, the area of puncture will be cleansed with the help of an antiseptic prior to the blood being drawn out.
While no special preparation is required for the test, you should make it a point to inform your doctor about any prescribed or non-prescribed medication that you may be under, as there is a possibility that they may interfere with the final test results.