Creatine kinase, serum

Protein Creatine kinase Serum Enzymatic Reviewed in Brancaccio et al. (2010)... 

Cardiac markers Troponin T (or I) Creatine kinase Serum or plasma ui- Possibly no Indicators of heart attack after 12 h... 

In vivo, patients treated with AZT develop a mitochondrial myopathy with mitochondrial DNA depletion, deficiency of cytochrome c oxidase (complex IV), intracellular fat accumulation, high lactate production and marked phosphocreatine depletion (Lewis and Dalakas 1995 Dalakas 2001). Clinically, the patient presents with fatigue, myalgia, muscle weakness, wasting and elevated serum creatine kinase. Muscle biopsy shows ragged red fibers , the characteristic histopathologic changes of mitochondrial myopathy, cansed by subsarcolemmal accumulation of mitochondria (Lewis and Dalakas 1995). 

A 33-year-old female patient treated with haloperidol for a history of schizophrenia is seen in the ED because of complaints of fever, stiffness, and tremor. Her temperature is 104°F, and her serum creatine kinase (CK) level is elevated. What has occurred ... 

Even between episodes, most patients have increased serum creatine kinase (CK) forearm ischemic exercise causes no rise of venous lactate concentration. This is a... 

Constipation occurs in fewer than 10% of patients taking statins. Other adverse effects include elevated serum aminotransferase levels (primarily alanine aminotransferase), elevated creatine kinase levels, myopathy, and rarely rhabdomyolysis. 

Swanson, J. R., and Wilkinson, J. H., Measurement of creatine kinase activity in serum. Stand. Methods Clin. Chem. 7, 33-42 (1972). 

T6. Tummistor, T., and Airaksinen, M. N., Increase of creatine kinase activity in serum caused by intermittently administered suxamethonium. Brit. J. Anaesth. 38, 510 (1966). 

Myopathy and neuropathy Colchicine myoneuropathy appears to be a common cause of weakness in patients on standard therapy who have elevated plasma levels caused by altered renal function. It is often unrecognized and misdiagnosed as polymyositis or uremic neuropathy. Proximal weakness and elevated serum creatine kinase are generally present, and resolve in 3 to 4 weeks following drug withdrawal. Maiabsorption of vitamin B-f2- Colchicine induces reversible malabsorption of vitamin B-12, apparently by altering the function of ileal mucosa. 

Adverse reactions occurring in patients may include abdominal pain, asthenia, diarrhea, dyspepsia, flatulence, headache, nausea. Laboratory abnormalities may include the following hematuria, increased ALT or AST, increased amylase, increased creatine kinase, increased serum creatinine greater than or equal to 0.3 mg/dL from baseline 4%. 

Lab test abnormalities include the following ALT, AST, creatine kinase, hematuria, neutrophils, serum amylase, serum glucose, triglycerides, urine glucose. 

The most common adverse effects of lamivudine seen at doses used to treat HBV are mild they include headache, malaise, fatigue, fever, insomnia, diarrhea, and upper respiratory infections. Elevated alanine aminotransferase (ALT), serum lipase, and creatine kinase may also occur. The safety and efficacy of lamivudine in patients with decompensated liver disease have not been established. Dosage adjustment is required in individuals with renal impairment. Coadministration of trimethoprim-sulfamethoxazole decreases the renal clearance of lamivudine. 

Correct answer = D. The CK isoenzyme pattern at admission showed elevated MB isozyme, indicating that the patient had experienced a myocardial infarction in the previous 12 to 24 hours. [Note 48 to 64 hours after an infarction, the MB isozyme would have returned to normal values.] On day 2, 12 hours after the cardioconversions, the MB isozyme had decreased, indicating no further damage to the heart. However, the patient showed an increased MM isozyme after cardo-conversion. This suggests damage to muscle, probably a result of the convulsive muscle contractions caused by repeated cardioconversion. Angina is typically the result of transient spasms in the vasculature of the heart, and would not be expected to lead to tissue death that results in elevation in serum creatine kinase. 

Hypersensitivity reactions, occasionally fatal, have been reported in 2-5% of patients receiving abacavir. Symptoms, which generally occur within the first 6 weeks of therapy, involve multiple organ systems and include fever, malaise, and gastrointestinal complaints. Skin rash may or may not be present. Laboratory abnormalities such as mildly elevated serum aminotransferase or creatine kinase levels are not specific for this reaction. Although the syndrome tends to resolve quickly with discontinuation of medication, rechallenge with abacavir following discontinuation results in return... 

Other techniques such as serum levels of muscle creatine kinase can also be used to assess dystrophy, but this requires great care in mouse handling. Creatine kinase is released from damaged... 

Creatine kinase (CK) is a dimeric enzyme with two subunits, M (muscle type) and B (brain type). Three isozymes are distinguished CK 1-BB (brain), CK 2-MB (heart), and CK 3-MM (skeletal muscle). The total CK activity found in skeletal muscle is almost entirely of the CK 3 type, that in heart muscle is 15-20% CK 2 and the remainder CK 3, and that in brain is all CK 1. In the human being, the only significant source of blood CK 2 is the heart muscle. Because the intact blood-brain barrier appears to be impermeable to CK, the occurrence of CK 1 in blood is unlikely. The total serum CK activity in healthy individuals is almost exclusively that of CK 3. 

The patient, a 63-year-old Caucasian female, was hospitalized on 4 April 2002 though 10 April 2002 for a non-ST segment elevation myocardial infarction (non-Q-wave MI per chart documentation). She had a negative adenosine stress test after the initial event. Her serum cardiac-specific troponin I (cTnl) concentration 24 hours after her onset of chest pain was 1.4 pg/L (upper limit of normal is 0.3 ng/mL), and her creatine kinase (CK) MB level was 12.5 pg/L (upper limit of normal 6.0 ng/mL). Three days post-event her cTnl level was 0.5 pg/L and her CK-MB level was 4.5 pg/L (Fig. 5-1). MB refers to one of the isoenzyme forms of CK found in serum. The form of the enzyme that occurs in brain (BB) does not usually get past the blood-brain barrier and therefore is not normally present in the serum. The MM and MB forms account for almost all of the CK in serum. Skeletal muscle contains mainly MM, with less than 2% of its CK in the MB form. MM is also the predominant myocardial creatine kinase and MB accounts for 10%-20% of creatine kinase in heart muscle. 

Figure 5-1. Time-course of changes in serum cardiac troponin I and creatine kinase MB (CK-MB) following myocardial infarction and subsequent reinfarction during hospitalization. Cardiac-specific troponin I (cTNI), open squares CK-MB, filled circles. Reprinted fromApple and Murakami (2005).

The procedure can be complemented by measuring the creatine-kinase MM (CK-MM) in the blood serum of the test animals. CK-MM is the muscle-specific enzyme which leaks out of a skeletal muscle if muscle damage has occurred. Determination of CK-MM should be conducted in the blood serum 24 hours after administration. 

Figure 16-3 Assay for serum creatine kinase (CK) activity.

The assays for serum glucose and creatine kinase were similar in many respects. List the chemical reactions that were common to both assays. Also, describe how these two similar assay systems could be used to quantify these two very different biomolecules. 

Why do you think that serum creatine kinase levels might be elevated in patients with seemingly unrelated conditions such as alcoholism and epilepsy ... 

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