The use of qualitative and quantitative polymerase chain reactions for diagnosis of cytomegalovirus infections in bone marrow and kidney transplant recipients

O objetivo deste trabalho foi testar uma PCR qualitativa e uma PCR semiquantitativa para CMV para determinar a carga de CMV nos leucócitos de pacientes transplantados de medula óssea e transplantados de rim. Trinta e três pacientes TMO e 35 TR participaram deste estudo. O DNA foi testado pela PCR qualitativa utilizando primers que amplificam parte do gene gB de CMV. As cargas de CMV das amostras positivas foram determinadas pela PCR semi-quantitativa utilizando como controle plasmídios quantificáveis inseridos com parte do gene gB de CMV. A sensibilidade do teste foi de 867 plamídios/µg DNA. Cargas de CMV entre 2.118 e 72.443 copias/µg DNA foram observadas em 12,1 por cento dos TMO entre 1,246 e 58,613 cópias/µg DNA foram observadas em 22,9 por cento dos TR. Futuros estudos, com maiores casuísticas são necessários para confirmar a utilidade desta PCR semiquantitativa para CMV em pacientes transplantados.

Diagnosis of cytomegalovirus infections by qualitative and quantitative PCR in HIV infected patients

A high incidence of cytomegalovirus (CMV) infections is observed in Brazil. These viruses are causatives of significant morbidity and mortality among patients with advanced human immunodeficiency virus (HIV) infection. This work, shows the application of a PCR on determination of CMV load in the buffy coat and plasma. We analyzed the samples of 247 HIV infected patients in order to diagnose CMV infection and disease. We developed a semi-quantitative PCR that amplifies part of the glycoprotein B (gB) gene of CMV. The semi-quantitative PCR was carried out only in positive clinical samples in a qualitative PCR confirmed by a nested-PCR. CD4 lymphocyte count, HIV viral load and CMV disease symptom were correlated with CMV load. CMV genome was detected in the buffy coat of 82 of 237 (34.6 percent) patients, in 10 of these the CMV load was determined varying between 928 and 332 880 viral copies/mug DNA. None of these 237 patients developed any suggestive manifestation of CMV disease. For the other 10 HIV infected patients selected based on the suspicion of CMV disease, CMV genome was detected in only one case. This patient presented a high CMV load, 8 000 000 copies/mug DNA, and developed a disseminated form of CMV disease including hepatitis and retinitis. Our results were greatly influenced by the impact of the highly active antiretroviral therapy that reduced incidence of CMV viremia and occurrence of CMV disease in the HIV infected patients