The liver and blood cells are responsible for creatine kinase clearance in blood Circulation: A retrospective study among different human diseases.

• Muscle damage leads to increased serum creatine kinase (CK) levels in diseases such as acute myocardial infarction. Still, many individuals have abnormal serum CK levels lacking muscle-related diagnoses. • The current study hypothesized that failed or overactivated CK clearance by non-muscle organs/tissues might be responsible for increased or decreased CK levels in blood circulation. Analyzing over 37,081 independent CK test results in 36 human diseases during the past five years, we found that 33 out of 36 diseases were associated with decreased median CK levels compared to healthy controls. • Besides muscle damage-related conditions, the highest mean CK levels were observed in hepatitis and cirrhosis. In contrast, six blood cell-related illnesses had the lowest mean CK values. ROC analysis showed that CK levels were the best biomarkers (AUC: 0.80–0.94) for the six blood-related diseases, especially myeloproliferative disorders. • The principal component analysis revealed that the same category of diseases, such as liver-, blood -, kidney-, cancers, and vascular-related diseases, had clustered CK distributions. • We proposed that the liver and blood cells were mainly responsible for CK clearance in blood circulation based on overall results. The testable mechanisms were presented and discussed. Muscle damage leads to increased serum creatine kinase (CK) levels in diseases such as acute myocardial infarction. Still, many individuals have abnormal serum CK activities lacking muscle-related diagnoses. The current study hypothesized that failed or overactivated CK clearance by non-muscle organs/tissues might be responsible for increased or decreased CK activities in blood. We analyzing 37,081 independent CK test results in 36 human diseases during the past 5 y. We found that 33 out of 36 diseases were associated with decreased median CK activities compared to healthy controls. Besides muscle damage-related conditions, the highest mean CK activities were observed in hepatitis and cirrhosis. In contrast, 6 blood cell-related illnesses had the lowest mean CK values. ROC analysis showed that CK activities were the best biomarkers (AUC: 0.80–0.94) for the 6 blood-related diseases, especially myeloproliferative disorders. The principal component analysis revealed that the same category of diseases, such as liver-, blood -, kidney-, cancers, and vascular-related diseases, had clustered CK distributions. We proposed that the liver and blood cells were mainly responsible for CK clearance in blood circulation based on overall results. The testable mechanisms were presented and discussed. [ABSTRACT FROM AUTHOR]