Influence of Hemolysis on Test Results

Specimen hemolysis is one of the most common interference and influence factors in clinical biochemical examination. Hemolysis leads to inaccurate test results, which cannot objectively reflect the patient’s physical condition at that time.

The influence of specimen hemolysis on clinical test results is as follows:

1. Influence on RBC Count and RBC Specific Volume 

In hemolysis sample RBC rupture, hemoglobin is released into serum, RBC count decreases with the degree of hemolysis, and RBC specific volume (Hct) decreases, which is proportional to the degree of hemolysis.

2. Influence on Coagulation Function Test

After hemolysis, the erythrocyte releases phospholipid, which activates partial thrombin time at N(PT) and prothrombin time. The determination process is pro-coagulant substances, resulting in a decrease in both results

3. Influence on HCV and HBsAg Results

The OD values of anti-HCV and HBsAg were significantly increased after hemolysis. Causing false positive test results. During hemolysis of the specimen, a large number of blood red eggs with peroxidase activity are released by the destruction and dissolution of the red blood cells, which has a similar effect with horseradish peroxides, producing non-specific color rendering, and can combine with the pre-coated antibody, increasing the OD value of the test results and producing false positive results. It has been reported that hemolysis has a great influence on HBsAg results. A false positive occurs when RBC concentrations greater than 25% rupture and hemolysis occur

4. Influence on the Analysis of Body Fluid Balance Blood Potassium Determination: 

Blood potassium increased after hemolysis; Determination of serum ion calcium: the concentration of serum free calcium can be directly determined by the ion selective electrode method. But this method is greatly affected by serum pH value. The pH value of red blood cell was 0.1 unit lower than that of serum, so the serum pH value decreased after hemolysis, and LML ion calcium increased. Determination of phosphate in serum: after hemolysis, organic phosphoric acid in blood cells hydrolyzed and inorganic phosphorus increased.

5. Effects on Enzymes

There is a significant difference between the content of enzymes in red blood cells and that outside of red blood cells. After hemolysis, the enzymes in red blood cells are released into serum or plasma, resulting in abnormal results of some enzymes in serum. CK, CKMB, LDH, HBDH and AST showed high hemolysis results. ALT, ALP, GGT and AMY had no significant difference

6. Influence on Myocardial Enzyme Spectrum Analysis

Hemolysis has obvious positive interference on myocardial enzymology index, especially on CK-MB. Slight hemolysis can double cK-MB, while severe hemolysis can increase its false value by more than 10 times, so it is not suitable to measure CK-MB in hemolysis specimens.

7. Influence on Blood Glucose and Blood Lipid Measurement

Hemolysis has positive interference to the determination of GLU, which is because glucose oxidase – peroxidase coupling method is mostly used in the determination of blood glucose at present, and the reaction products are red quinone imines. Hemoglobin can directly deepen the red of the reaction products and produce positive interference to the determination result, making the result higher. Hemolysis had little effect on the determination of blood lipids.

8. Influence on Renal Function

After hemolysis, the creatinine value decreased, but the change of urea value was not obvious, but there were also creatinine and uric acid value increased, especially the significant increase of creatinine, but also the phenomenon of uric acid decrease

Prevention

Using conventional pipe diameter needles and vacuum vessels, for patients with venous catheter in patients with severe or thin carefully take blood, avoid taking blood from hematoma area and prolong the acting time, tourniquet don’t stir energetically samples and at the right temperature and humidity in blood, in addition, still should master specimen transportation, preservation, centrifugal, conditions and methods of the separating supernatant. Non-anticoagulant specimens should be placed for a period of time, preferably in a water bath (37) for preheating for 30 min, and then centrifuged after the clot contracted, and the serum was separated in time.

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