The presence of macro creatine kinase type 2 (MCK2) activity was noted in the serum of seven out of 32 newborn infants with perinatal asphyxia or birth trauma. MCK2 isoenzyme, when present, represented 15-35% of the total creatine kinase (CK) activity. The clinical and biochemical features of the seven MCK2-positive and 25 MCK2-negative newborns were compared. The infants with MCK2 activity were all males and clinically appeared to be more severely injured, requiring longer hospitalization. Total CK activity was similar in the two groups and CK-MB and CK-BB isoenzyme fractions were present in a similar proportion of infants in both groups. Two infants in each group had long-term neurological disorders. Although the presence of MCK2 has been noted in adult patients with end-stage metastatic solid tumors, the presence of this isoenzyme has not previously been reported in newborn infants.
KEY WORDS: mitochondrial creatine kinase; type 2 macro creatine kinase; birth trauma; asphyxia; metastatic carcinoma. ported in seven children with cardiac disease, ranging in age from 4 days to 4 years (15,16).
Recently, by upgrading our electrophoresis procedure we first noted the presence of MCK2 activity in the serum of a full-term infant who had suffered a traumatic delivery. During the ensuing 6-month period MCK2 was noted in an additional six infants with birth trauma or perinatal asphyxia.
To the best of our knowledge, the presence of serum MCK2 has not been previously reported in newborn infants. This study evaluates the clinical and laboratory features and outcome of this group of asphyxiated newborn infants compared to infants in whom MCK2 was not detected.