Cytomegalovirus

Called cytomegalovirus ( CMV ) or cytomegalovirus ( CMV), incorrect as human cytomegalovirus ( HCMV) or human herpes virus 5 (HHV 5), is an enveloped, double-stranded DNA virus ( dsDNA), belongs to the family Herpesviridae and is the world widespread. Transmission occurs via saliva, urine, semen, and secretions in the blood transfusion.

Special Features

The virus has a total diameter of about 200 nanometers and its genome consists of a linear double-stranded DNA of approximately 230,000 base pairs that encode 151 different genes. Its constructed from different capsomeres icosahedral capsid is surrounded by a lipid membrane. These viral envelope glycoproteins six against which the host organism may produce antibodies. The membrane envelope is also the reason that the virus outside the organism can survive for only a short time and easily dry out. In addition, the virus to ethanol, solvents, detergents and acids is very sensitive.

Characteristic of this virus is - as well as for all other species of the family Betaherpesvirinae - a narrow host range and a strikingly slower replication cycle. The infected cells are usually greatly enlarged ( cytomegalovirus - in the sense of giant cell formation), which is why the virus was also named so.

Dissemination

The human cytomegalovirus occurs throughout the world in general ( ubiquitous ), the infection rate is dependent on the standard of living 30 to 90 %.

Diagnostics

Routinely, the detection of infection in the laboratory in a few minutes from human serum and plasma are performed in vitro assays for the quantitative determination of IgG and IgM antibodies against cytomegalovirus by immunological. The results of this test as proof of an expired or recently acquired CMV infection. An indication for use is given in pregnant women and blood donors. In addition can be done in human connective tissue cells a Virusanzüchtung, the observable after several weeks of cell changes ( detachment of infected cells from the cell structure, giant cell formation with cytoplasmic inclusion bodies, so-called " owl eyes ", see Tzanck test) are typical of CMV infection ( cytopathic effect ). A much faster diagnostic detection is performed by real- time PCR. In addition, the CMV is detected during acute infection on the pp65 antigen. However, the infection is in a latent phase, ie in a period without symptoms, only the pp67 antigen can be detected. This can therefore be used for a successful therapy control.

Infection episodes

The virus causes humans to cytomegalovirus. The initial infection with human cytomegalovirus runs in 99% of cases with no or only minor symptoms. The main symptom is high, sometimes for weeks, persistent fever with typically elevated liver values. Life-threatening complications such as myocarditis, thrombocytopenia or pneumonia are rare in the immunocompetent, so no antiviral therapy should be started. In immunocompromised patients, however, CMV -infection or CMV reactivation lead to serious problems. There may be a CMV -associated colitis with diarrhea in renal transplant people can manifest CMV reactivation to a graft function deterioration, and possibly even loss of the graft lead. In 30% of AIDS patients who are not receiving highly active antiretroviral therapy, the virus infects the retina and leads to blindness.

Infection with cytomegalovirus is also associated with high blood pressure and arteriosclerosis.

Therapy

A fight the infection with HCMV is usually necessary only in transplant patients. In a study of 230 patients, the efficacy of the drug CMX001 was shown.