Quantitative polymerase chain reaction for human herpesvirus diagnosis and measurement of Epstein-Barr virus burden in posttransplant lymphoproliferative disorder
CLINICAL CHEMISTRY
Authors: Bai, X; Hosler, G; Rogers, BB; Dawson, DB; Scheuermann, RH
Abstract
Human herpesviruses can cause acute diseases such as chicken pox or mononucleosis, but also may reactivate during immunosuppression and result in severe or life-threatening illnesses such as shingles or lymphoproliferative disorders. We report the development and validation of a quantitative PCR method to measure viral burden for all eight human herpesviruses (HSV1, HSV2, VZV, EBV, CMV, HHV6, HHV7, and KSHV) in patients' samples. The method uses an internal standard that is coamplified with the viral target, allowing quantification of viral genomes in absolute terms (e.g., viral targets/mL of blood) and ruling out false-negative results. We demonstrate that transplant patients with lymphoproliferative disorder carry an EBV viral burden 3 logs higher than nontransplant patients. EBV titers in transplant patients without a lymphoproliferative disorder are between these values. This quantitative PCR method may aid in differentiating clinically significant vs latent viral burden in immunosuppressed patients.
Are exposure to cytomegalovirus and genetic variation on chromosome 6p joint risk factors for schizophrenia?
ANNALS OF MEDICINE
Authors: Kim, Jung Jin; Shirts, Brian H.; Dayal, Madhulika; Bacanu, Silviu-Alin; Wood, Joel; Xie, Weiting; Zhang, Xiaohua; Chowdari, Kodavali V.; Yolken, Robert; Devlin, Bernie; Nimgaonkar, Vishwajit L.
Abstract
Background. Published data support genetic variants, as well as certain infectious agents, as potential risk factors for schizophrenia. Less is known about interactions between the risk factors. Aim. To evaluate exposure to infectious agents and host genetic variation as joint risk factors. Methods. We investigated four infectious agents: cytomegalovirus (CMV), herpes simplex viruses 1 and 2 (HSV1, HSV2), and Toxoplasma gondii (TOX). We initially compared exposure using specific serum antibodies, among simplex and multiplex nuclear families (one or more than one affected offspring, respectively). If interactions between infectious agents and host genetic variation are important risk factors for schizophrenia, we reasoned that they would be more prominent among multiplex versus simplex families. We also evaluated the role of variation at chromosome 6p21-p23 in conjunction with exposure. We used 22 short tandem repeat polymorphisms (STRPs) dispersed across this region. Results. Though exposure to all four agents was increased among multiplex families versus simplex families, the difference was consistently significant only for CMV (odds of exposure to CMV in multiplex families: 2.47, 95% CI: 1.48-5.33). Transmission disequilibrium tests and case-control comparisons using STRPs revealed significant linkage/association with D6S2672 among CMV+ schizophrenia patients. Conclusions. Polymorphisms near D6S2672 could confer risk for schizophrenia in conjunction with CMV exposure.