Abstract

Objective: It is difficult to distinguish cytomegalovirus (CMV) infection and disease since CMV is a latent virus and can cause recurrent infections. Positive CMV tests may not necessarily be indicative of active disease. There is no clear threshold value for plasma CMV-DNA polymerase chain reaction (PCR) levels to distinguish disease from viral reactivation. In this study, we aimed to determine a numerical value to identify CMV-related clinical syndromes and to differentiate between CMV infection and disease in HIV/AIDS patients.

Methods: HIV/AIDS patients aged ≥18 years with a positive CMV viral load in plasma of any titer were included in the study. Sociodemographic, clinical, and laboratory data were extracted from patient files. Cytomegalovirus-related disease was defined as the isolation or detection of viral proteins or nucleic acid in a tissue sample or any body fluid in the presence of clinical signs related to the organ involved. CMV infection was diagnosed based on evidence of CMV replication without CMV symptoms or signs. A ROC curve was created to determine a cut-off value to distinguish CMV infection and disease.

Results: Eighteen patients had CMV-related disease, and 18 had CMV infection. Clinical and laboratory parameters were compared between the two groups. The end organs’ involvement was detected in the CMV disease group, and gastrointestinal involvement was the most common.  The CMV-DNA PCR threshold level among patients with CMV disease and infection was determined as 3154 copies/mL. The risk of CMV disease increased with decreasing CD4⁺ T lymphocytes count and increasing HIV viral load.

Conclusion: Since CMV illness can have life-threatening effects, a precise and prompt diagnosis is essential. Antiviral therapy can reduce the morbidity and mortality of CMV infection. The CMV-DNA PCR threshold level determined in this study will guide clinicians in the early diagnosis of CMV disease.

Keywords: CMV, HIV, polymerase chain reaction, antiretroviral therapy