Detection of glycoproteins B and H genotypes to predict the development of Cytomegalovirus disease in solid organ transplant recipients

Abstract

Background: Our study focuses on the role that human Cytomegalovirus (CMV) genotypes play in the development of disease.

Objectives: (1) To analyze the frequency of various genotype envelope proteins (gB, gH) in a group of solid organ transplant (SOT) recipients; (2) to assess their correlation with CMV disease; (3) to study the association between any of the genotypes and viral loads.

Study design: A retrospective observational study conducted by analyzing CMV gB and gH genotypes detected with real-time polymerase chain reaction (PCR)-specific assays in 162 CMV-positive blood samples from 62 SOT recipients. Demographic, clinical, and microbiological data were recorded.

Results: Mixed gB genotypes were associated with viral syndrome (70%, p = .004), earlier presentation of symptoms (48.27 ± 27.03 versus 74.33 ± 47.25 days, respectively, p = .001), and higher median of the plasma viral load log₁₀ (UI/ml) than infection with a single genotype (p = .004). Furthermore, the gB3 genotype was detected more frequently in patients who presented with asymptomatic viremia (77.27%, p < .0001). The gH1 genotype was more frequent (65%) in patients who presented with asymptomatic viremia (p = .003), and it caused infection later than gH2 or the mixed genotype (84.88 ± 48.10 versus 57.91 ± 39.18 days, respectively, p < .001).

Conclusions: Patients who presented mixed gB genotypes more frequently developed clinical manifestations and earlier, higher, plasma viral loads. The detection of gB and gH genotypes by real-time PCR can provide relevant information to stratify the risk of SOT recipients to develop symptomatic infection by CMV.

Keywords: CMV genotypes; Prognosis; Transplantation; Viral load.