Elevated serum alkaline phosphatase levels in a renal transplant patient precede colitis

An asymptomatic, but highly significant, rise in serum alkaline phosphatase (AP) levels developed in a renal transplant recipient. Investigations ruled out bony or hepatobiliary disease. Subsequent diarrhea and weight loss led to a diagnosis of cytomegalovirus (CMV) colitis, which was confirmed with a positive CMV pp65 antigenemia test and an endoscopic finding of multiple colonic erosions. Intravenous ganciclovir led to complete patient recovery and a swift reduction of serum AP levels to normal. Normally, intestinal AP isoenzymes are cleared quickly from the circulation. However, acute bowel diseases, especially when inflammatory in origin, can produce high serum AP levels. In this presented patient, the rise in serum AP levels preceded symptomatic manifestations of CMV colitis, and fell with successful therapy. Acute CMV disease in solid organ transplant recipients is common, can take many shapes, and needs to be diagnosed quickly. An unexplained rise in serum AP levels should lead to a search for inflammatory bowel disease, specifically CMV colitis, in transplanted patients.