red blood cell life span (RBCS) refers to the survival time of red blood cells released from bone marrow into peripheral blood. In the physiological state, the production and destruction of red blood cells were dynamically balanced, and the average RBCS in healthy adults were 115 (70-140) days. Under pathological conditions, no matter what mechanism-mediated increase in erythrocyte destruction (i.e. hemolysis) can lead to shortening of RBCS. When erythrocyte destruction exceeds bone marrow compensatory hyperplasia, it leads to anemia. There are existing laboratory indicators that reflect increased red blood cell destruction (such as increased red blood cell fragments, decreased plasma haptoglobin, increased free hemoglobin, hemoglobinuria, hemosideruria, increased serum unconjugated bilirubin, and increased lactate dehydrogenase level) and laboratory indicators of compensatory hyperplasia of bone marrow erythroid due to hemolysis (such as increased proportion of bone marrow erythroid, increased reticulocytes, etc.), but the above indicators are affected by many factors, and their sensitivity and specificity are not high[1,2]Early or mild atypical hemolysis cannot be determined in time and accurately. RBCS are the earliest and most direct indicators to reflect the destruction of red blood cells, so the detection of RBCS is of great value in clinical diagnosis and differential diagnosis of hemolysis.
