Detection of antibody to cytomegalovirus-induced early antigens and comparison with four serologic assays and presence of viruria in blood donors

High seropositivity of IgG and IgM antibodies against cytomegalovirus (CMV) among HIV-1 seropositive patients in Ilorin, Nigeria

BACKGROUND

Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is a major public health problem in sub-saharan Africa. Cytomegalovirus (CMV) has been reported to enhance HIV replication and accelerate the progression of HIV infection to AIDS.

OBJECTIVE

This study reports on the high seropositivity of immunoglobulin (Ig) G and M antibodies against CMV and the risk factors for CMV infection among HIV/AIDS patients in Ilorin, Nigeria.

METHOD

A total of 180 consented HIV-1 seropositive patients (age-range 16-56 years; 108 females and 72 males) were consecutively recruited. Socio-demographic/behavioral data and 5 ml blood samples were collected from each patient. Plasma of each sample was assayed for anti-CMV IgG/IgM using a CMV IgG and IgM Enzyme Linked ImmunoSorbent Assay (ELISA) kit.

RESULTS

Twenty (11.1%) of the 180 HIV-1 seropositive subjects were positive for anti-CMV IgM antibody while 169(93.9%) were positive for anti-CMV IgG antibody. Age, marital status, number of sexual partners, CD4 cells counts and previous history of blood transfusion were the main correlates of CMV seropositivity among these patients. However, occupation, sex, highly active antiretroviral therapy (HAART) were not statistically associated with CMV seropositivity in this study.

CONCLUSION

This study has shown that greater percentages of HIV-1 seropositive patients had active CMV infection. It has further shown that CMV is hyperendemic in HIV-1 seropositive patients in Ilorin, Nigeria.

Early serodiagnosis of acute human cytomegalovirus infection by enzyme-linked immunosorbent assay using recombinant antigens

DNA fragments from eight different reading frames of human cytomegalovirus (HCMV) were generated by PCR and subsequently cloned and expressed in Escherichia coli in fusion with glutathione S-transferase. The recombinant viral antigens were evaluated in immunoblot analyses. The most reactive antigens were purified and further evaluated in ELISAs. For this, sera from healthy blood donors and immunocompetent individuals with acute HCMV infection, and follow-up sera from transplant recipients with acute primary HCMV infection were used. The results of our experiments indicate that only three particular recombinant polypeptides from two viral proteins are necessary for serodiagnosis. While a fragment covering amino acids (aa) 495 to 691 of pp150 (150/1) was the most suitable antigen for the identification of infected individuals in general, immunoglobulin M antibodies against the C-terminal parts of pp150 (aa 862 to 1048; 150/7) and p52 (aa 297 to 433; 52/3) proved to be excellent serological markers to monitor acute HCMV infection. The selected recombinant antigens enable the improvement of serodiagnosis of HCMV-related diseases, especially during the early stages of infection.

Cytomegalovirus and latency: an overview

Cytomegalovirus (CMV) is a member of the herpes virus group. Infection results in a variety of disorders which depend largely on the immune status of the host. A well known property of CMV is that after primary infection the virus persists in the body of the host resulting in latency. Severe immunodepression or immunodeficiency can cause reactivation of the virus from its latent state, leading to endogenous reinfection. In contrast to other herpes viruses, such as herpes simplex virus which persists in neurons, and Epstein Barr virus which persists in B lymphocytes, little is known about the localization of latent CMV. In order to obtain more insight in the organ or cell type serving as a reservoir for latent CMV, it is important to know more about the course of natural infection and the cells and organs involved. When more information is available about the localization of latent virus, studies concerning the physical state of viral DNA or the extent of viral transcription and/or translation will follow in the near future. In this review some properties of the epidemiology and transmission of human CMV, as well as data about acute infection will be given. In addition, some characteristics of the localization of latent CMV and the physical state of the virus will be discussed. Where necessary, particularly regarding insight into CMV-host interactions, knowledge of animal, particularly murine, rat and guinea pig CMV infections, will be discussed.

Cytomegalovirus studies on blood donors in north-east Scotland and a review of UK data

The epidemiology of cytomegalovirus (CMV) infection as assessed by CMV antibody testing varies significantly in different parts of the world and also in different regions of a country. A study was therefore carried out to assess the prevalence of CMV antibody in our blood donors, looking in particular at different subgroups of donors as divided by age, sex and social class, to see how we could maximise the yield of CMV-negative blood from our testing. It was shown that patterns of CMV infection in the North East of Scotland followed well-established norms. Data from other Regional Transfusion Centres within the UK were also collected for comparison.

The incidence and consequences of cytomegalovirus transmission via blood transfusion to low birth weight, premature infants in north east Scotland

In a 2-year study involving 133 premature low birth weight (less than 1,500 g) infants, the impact of CMV infection via blood transfusion was assessed. 8.4% (7 out of 83) of transfused infants and 10% (7 out of 70) of those exposed to seropositive blood acquired CMV. In those less than 1,250 g the infection rate rose to 13.2% (7 out of 46). Seropositive infants were at a higher risk of acquiring CMV infection than seronegative ones. CMV infection did not give rise to specific immediate morbidity, and no deaths were attributed to CMV. The only source of nosocomial CMV infection was the transfused seropositive blood. Based on these findings, it was possible to formulate a CMV transfusion policy to premature infants in our region.

Acquisition of cytomegalovirus infection: an update

Human cytomegalovirus (CMV) is a ubiquitous deoxyribonucleic acid virus that commonly infects a majority of individuals at some time during their life. Although most of these CMV infections are asymptomatic, certain patient groups are at risk to develop serious illness. Understanding the epidemiology of this virus is a key element in the development of strategies for preventing CMV disease. However, a number of features of this virus complicate such understanding. Following infection, CMV can remain latent, with subsequent reactivation; the factors controlling latency and reactivation and those factors which determine whether a CMV infection will be symptomatic are unknown. CMV disease can be acquired by natural routes, including horizontal and vertical transmission. Due to the ubiquity of CMV, the delineation of CMV transmission by these natural routes is complicated by the myriad of possible sources. Moreover, concerns over the risk of CMV transmission to the seronegative pregnant female have been raised in relation to preventing CMV transmission. By using molecular biologic techniques, much knowledge has been gained regarding the transmission of CMV disease by natural routes; however, a number of questions remain unanswered. The transmission of CMV infection by natural routes is therefore reviewed and the issues are highlighted. Primary infection, reactivation, and reinfection are the types of active CMV infections that can occur in an immunocompromised patient. In addition to natural routes of infection, introduction of presumably latently infected organs and requirements for multiple blood transfusions increase potential exposure to CMV in the immunocompromised patient. Understanding the epidemiology of CMV infections in the immunocompromised patient is difficult and in some instances controversial due to the complexity and interdependency of a number of factors which lead to CMV infection. In an immunocompromised individual, a major risk factor in developing overt CMV-related disease is associated with the serological status of an organ donor, the recipient, and the blood product given to these patients. In addition, a large body of inferential data supports the transmission of CMV by blood products or organs from seropositive donors; however, the mechanisms by which transmission occurs remain unclear. The possible sources and mechanisms of transmission of CMV infections in the immunocompromised host are reviewed. Lastly, strategies for the ultimate prevention of CMV disease are discussed in light of the epidemiology of CMV infections. To date, these strategies have included use of CMV-seronegative blood products or organs, antiviral agents, and vaccines.(ABSTRACT TRUNCATED AT 400 WORDS)