Introduction: Creatine-phosphokinases (CPK) are rarely increased in Crohn’s disease (CD). Exceptionally, CPK electrophoresis can reveal an abnormal isoenzyme so-called macro-CK: type I in autoimmune, heart or muscular diseases and type II in neoplasia.
Methods: We report a case of macro-CK I discovered in a teenager treated for CD, diagnosed at the age 14, in November 2001: poor general condition (weight: 34.4 kg, –3DS, height 1.55 m, –0.5 DS, BMI = 14.2 kg/m2), severe anemia, and inflammatory syndrome.
General corticotherapy is initiated, leading to a clinical and biological remission, until May 21, 2002. Relapse prevention through mesalazine (40mg/kg/j) is begun on May 10, 2002.
Results: After seven months of treatment, a CPK moderate elevation (1.1 ×N) is discovered with a CPK-MB fraction raised to 44% (N <25 %). Troponin Ic, myoglobin determinations and ECG are normal. There is neither functional muscular complaint nor clinical signs of relapse.
On CPK electrophoresis, macro-CK1 could be found, migrating near CPK-MM band and estimated at 18.4 %. Mesalazine treatment is immediately stopped on December 2nd, 2002.
A slow but irregular CPK and CPK-MB fraction decrease (respectively from 2.1 to 0.9 ×N and 52 to 39, 9 %) is noticed during the next six months. Macro-CK is still found at a level of 21.4 % and then at 15.6 % on June 25, 2003. At this time, a new evaluation is in progress to look for a total disappearance which could then favor the drug hypothesis.
Conclusion: Macro CK is rarely reported in children, mainly in those with heart diseases. In adults, it’s associated with myocardic infarct, myopathic and autoimmune diseases: essentially ulcerative colitis in digestive domain, without any direct link with clinical relapse.
In our case, macro-CK presence can be attributed to Crohn’s disease and/or to mesalazine treatment. Indeed, in medical literature, macro-CK has been yet reported in 2 cases with mesalazine treatment: Crohn’s disease with induced lupus and also in young women with ulcerative colitis.
It would be emphasized that in our observation, CPK was normal (0.9 ×N) nineteen days after treatment beginning. Was it too early to see IgG-CPK-BB complex appearance? Similarly, several Crohn’s disease cases with myositis have been described.
In fact, macro-CK is not synonymous of myolyse, but due to IgG-CPK BB complex formation in most cases, either it could be disease or drugs related.