Last update:
07-Jul-2004

This study illustrates the power of molecular biology techniques based on PCR in the elucidation of cytomegalovirus (CMV) infection in a ΗΙV-1(+) patient. CMV is responsible for the most common viral opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). The colon is a common site of CMV infection in AIDS patients. Clinical diagnosis of CMV infection is based on the characteristic endoscopic appearance of extensive ulceration of the gastric mucosa. A 54 year-old homosexual man who had AIDS complicated by CMV visited the hospital because of high fever. PCR tests for Legionella, Chlamydia pneumoniae, Pneumocystis carinii and Aspergillus were negative. In addition, the patient presented with diarrhea and DNA prepared from biopsies of colon ulceration sampled on colonoscopy scored positive for CMV. Ganciclovir was administered, with good clinical response but diarrhea recurred six months later. PCR for CMV scored positive again and the emergence of CMV mutants conferring ganciclovir resistance was investigated. The presence for the most common mutations of the UL97 gene associated with ganciclovir resistance was directly assessed in DNA from the patient’s leukocytes. Direct sequencing of the PCR products revealed the known V594 mutation predisposing to ganciclovir resistance, and the same gene polymorphism (579, GGCGGT and 598, GGTGGC) in all samples tested. Finally the patient died. In summary, molecular biology methods can be used for early detection of CMV in characteristic colonic lesions in AIDS patients. Detection of mutant strains resistant to antiviral drugs and polymorphism may elucidate the natural history of the infection in the particular patient.

Key words: CMV, Ganciclovir, HIV-1, Resistance.