Etiological detection for cerebral parenchymal opportunistic infections in AIDS patients by PCR

Background: Central nervous system (CNS) opportunistic infections (OIs) is one of the most important complication in Acquired Immune Deficiency Syndrome (AIDS) patients. As far as the cerebral parenchymal OIs (encephalitis) are concerned, the sensitivity and specificity of pathogens routine test methods are not highly acceptable at present. Objective: Detect the pathogens of cerebral parenchymal OIs in AIDS patients by polymerase chain reaction (PCR), to evaluate the utility of this method, and observe the etiology characteristics of cerebral parenchymal OIs and their impact on the prognosis in AIDS patients. Methods: We conducted a retrospective study design involving 33 formalin-fixed paraffin-embedded tissue (FFPET) samples of cerebral inflammatory lesions in AIDS patients from 2012 to 2020 were retrieved from the Department of Pathology, Beijing Ditan hospital affiliated to Capital Medical University. Pathogen-specific primers were used to detect DNA from cytomegalovirus (CMV), toxoplasma gondii (TG) and John Cunningham virus (JCV), via real-time PCR. Follow-up visits were conducted by telephone and outpatient service. Survival time after operation was counted. Results: Of 33 samples sent for PCR, 90.91% (30/33) were positive, 33 pathogens detected. JCV accounted for 60.61% (20/33) of all causes of cerebral parenchymal OIs, 21.21% (7/33) for CMV, 18.18% (6/33) for TG. IgG antibody against TG in serum (P=0.005) and in CSF (P=0.013) obviously correlated with TG expression in FFPET. The 0 pathogen patients tend to suffer from solitary lesion (P=0.018). JCV positive patients in FFPET tended to have higher odds of death (P=0.0096), whereas patients with TG positive showed lower odds of death (P=0.0431). Conclusion: JCV is the most prevalent pathogen of cerebral parenchymal OIs among AIDS patients, and tend to have a poor prognosis. The utility of the diagnostic method for pathogen identification by PCR combined with the investigation of etiological characteristics may improve the diagnosis and prognosis of AIDS related cerebral parenchymal OIs patients.