HyperCKemia-MB due to macroCK type 1: Case report

HyperCKemia is a rare condition characterized by a persistent increase in serum creatine kinase (CK) levels or some isoenzymes. Usually, there are no clinical, electromyography or histological manifestations, which involves a challenge at the time of diagnosis. The patient in question showed no characteristic signs or symptoms, apart from fatigue and post-exercise myalgia. Assessment was performed by rheumatology and endocrinology, determination of total CK and MB fraction in blood, and electromyography and protein electrophoresis were requested as part of the approach. This case report is considered as novel, interesting, and useful for clinical practice as few similar ones were found in the scientific literature. The difficult etiological diagnosis of this entity, and the algorithm used to arrive at it, are all presented. It is concluded that in those patients with hyperCKemia of unknown etiology, this diagnosis should be kept in mind, and be confirmed by performing a CK electrophoresis.

La hiperCKemia es una condición poco frecuente caracterizada por un aumento persistente de los niveles de creatina quinasa (CK) sérica o de algunas isoenzimas, sin que suelan presentarse manifestaciones clínicas, electromiográficas o histológicas, lo cual implica un desafío a la hora del diagnóstico. El paciente cuyo caso se presenta aquí no mostró signos o síntomas característicos, únicamente fatiga y mialgias posteriores al ejercicio. Se llevó a cabo valoración por reumatología y endocrinología, determinación de CK total y fracción MB en sangre; además, se solicitó electromiografía y electroforesis de proteínas como parte del abordaje. Consideramos que este reporte de caso es novedoso, interesante y de utilidad para la práctica clínica pues se encuentran pocos similares en la literatura científica; adicionalmente, se pone en evidencia el difícil diagnóstico etiológico de esta entidad, así como el algoritmo utilizado para llegar a ella. Se concluye que este diagnóstico debe tenerse en mente en aquellos pacientes con hiperCKemia de etiología desconocida, y para confirmarlo es necesario hacer una electroforesis de CK.

A Patient's Post-Cardiovascular Surgery Needs for the Differential Diagnosis of Postoperative Myocardial Ischemia Because of Macro Creatine Kinase / 日本心臓血管外科学会雑誌

A 61 year old woman who had been receiving treatment for ulcerative colitis for 14 years complained of respiratory discomfort on exertion and was diagnosed with severe mitral regurgitation due to mitral valve prolapse. Minimally invasive mitral valvuloplasty with right mini-thoracotomy was performed in our facility. Laboratory findings showed elevated levels of serum creatine kinase (CK) and CK-MB immediately after surgery. In addition to elevated levels of myocardial enzymes, ST depression was seen in an electrocardiogram on postoperative day 2 ; therefore, we suspected myocardial ischemia during the surgery. Despite the persistently elevated levels of myocardial enzymes, coronary angiography showed no significant abnormalities. Because of the possibility of false CK elevation, we performed CK electrophoresis, which revealed the presence of macro-CK type 1. CK-MB activity is often falsely elevated when determined by immune-inhibition in macro-CK patients, and that leads to the suspicion of myocardial ischemia. We considered that it may be highly difficult to identify macro-CK in a patient after cardiovascular surgery owing to elevated levels of myocardial enzymes in most such patients.

Laboratory and clinical features of abnormal macroenzymes found in human sera.

We report the analysis of unusual macroenzymes, performed in our laboratory, and review the relevant literature. In particular, we focused on macro AST, macroamylase, macro LD and macro CK. Macroenzymes are seen in healthy subjects, but can also be related to disease; thus, accurate detection is useful in day-to-day clinical practice. The macroenzyme is thought to be a specific antigen-antibody complex from the following findings: (1) the complex could be dissociated under acidic pH levels; (2) binding specificity of immunoglobulin in the complex was observed; (3) the binding site of immunoglobulin in the complex was Fab portion; and (4) the maternal IgG involved with macroenzyme was transferred to her children. This article is part of a Special Issue entitled: Medical Proteomics.

High Creatine Kinase (CK)-MB and Lactate Dehydrogenase in the Absence of Myocardial Injury or Infarction: A Case Report.

Acute myocardial infarction (AMI) is a life threatening condition that needs emergency diagnosis and early treatment in the emergency room. Rapid laboratory testing for creatine kinase (CK)-MB greatly revolutionized the diagnosis and management of acute myocardial infarction. We report a case with chest pain that referred to the emergency department (ED). Laboratory data showed high serum levels of creatine kinase and lactate dehydrogenase. With diagnosis of acute myocardial infarction, he was hospitalized and angiography was performed which showed three vessels disease; the patient was referred to surgical ward for coronary artery bypass graft. Surgery was performed after one week; during the operation there was no sign of infarction over the heart. Our observation suggests that false positive laboratory result may be due to other condition which must be evaluated.

Macro creatine kinase type 1: a cause of spuriously elevated serum creatine kinase associated with leukoencephalopathy in a child.

Macro creatine kinase type 1 is a complex formed by the creatine kinase isoenzyme BB and monoclonal IgG and occurs in about 1% of patients studied. First identified as a cause of spurious elevation of the total serum creatine kinase in patients suspected of myocardial infarction, the test has been largely replaced by the measurement of troponin levels. We present a child with delayed milestones and persistently elevated total serum creatine kinase measurements (∼ 1000-4000 IU) normal electromyogram and brisk myotatic reflexes. Creatine kinase isoenzymes and brain imaging showed the presence of macro creatine kinase type 1 and extensive signal abnormality of the cerebral white matter. Macro creatine kinase type 1 has been associated with several conditions though it has not been described in association with leukoencephalopathy or in patients this young. Macro creatine kinase type 1 can be a cause of elevated total creatine kinase in patients without primary muscle disease. The significance of the relationship of the macro creatine kinase to the leukoencephalopathy in this patient is unknown.

Anomalous Activity Measurements of Creatine (Phospho) Kinase, CK-MB Isoenzyme in Indian Patients in the Diagnosis of Acute Coronary Syndrome.

In the present study, the cause of suspected false-positive (anomalous) values for CK-MB activity, in Indian patients investigated for ACS. Total serum CK and CK-MB activity, serum Troponin I were measured and CK-MB as a percentage of the total CK activity (%CK-MB) calculated. CK-MB was also estimated using densitometry and CK-MB mass assay. Anomalous specimens were tested for the presence of CK isoenzymes. In 22 healthy subjects, 11 male and female, the %CK-MB ranged from 3.6 to 30.2. In 11 male patients, with proven ACS, the %CK-MB was from 4.0 to 17.5. The cut off for anomalous CK-MB activity values was set as >33.0%. In 35 patients with anomalies, total CK values ranged from 39 to 231 U/L, CK-MB from 30 to 161 U/L. Investigation of CK isoenzymes, showed 10 patients had a CK-BB band, 14 an intermediate band between CK-MM and CK-MB (macro-CK type 1), 7 had a cathodal band (macro-CK type 2), and 3 had a band intermediate between CK-MB and CK-BB. This later band does not seem to have been previously reported. Against the CK-MB mass assay, the activity assay showed no correlation, in 43 patients (19 M, 24 F), Pearson coefficient (R(2)) was 0.006. The CK-MB immunoinhibition assay is better described as measuring "non-CK-MM activity." A %CK-MB activity >6% as a marker of ACS is not valid in our patient population. Laboratories should not use only CK-MB activity as a biochemical marker of ACS.