Key marker of hemolysis
Haptoglobin is synthesized by the liver and binds hemoglobin released when red blood cells are destroyed. As hemolysis increases, haptoglobin is used up faster than it is produced, and its level in the blood drops—to the point of being completely absent. This is one of the most sensitive signs of hemolytic anemia, along with an increase in indirect bilirubin and LDH. The indicator is used to diagnose autoimmune hemolysis, reactions to blood transfusion, hemolysis with artificial heart valves. There is a nuance: haptoglobin is an acute phase protein and increases during inflammation, so when hemolysis is combined with infection, its level may turn out to be falsely normal.
Why preparation is so important
The laboratory result is a number, but the correct number can only be obtained if the rules are followed. Eating changes the levels of glucose, lipids and a number of enzymes significantly; physical activity the day before increases CK and AST; smoking affects hormones; time of day is critical for cortisol and testosterone.
Therefore, a “bad analysis” often turns out to be a consequence of impaired preparation, and not an illness, and leads to unnecessary examinations and prescriptions.
General rules for donating blood
- on an empty stomach 8–12 hours, you can drink water
- Eliminate alcohol and intense exercise per day
- no smoking in an hour
- donate blood before physiotherapy, x-rays and massage
- Take medications in advance by agreeing with your doctor
- for hormones in women, take into account the day of the cycle
How to read the result
Reference values depend on the method and equipment of the laboratory, so it is correct to compare results only within the same laboratory. A deviation of a few percent from the normal limit in itself rarely matters - the overall picture and dynamics are important. It is up to the physician to interpret the analysis: an isolated indicator without a clinical context is often misleading.