Immunoblot for the detection of IgG/IgM/IgA-antibodies against Cytomegalovirus in serum

SUMMARY AND EXPLANATION OF THE TEST

Using the this it is possible to determine the stage of a CMV infection. This is achieved by differentiating between immediate early antigen (52 kD), early antigen (66 kD) and late antigen (150 kD). With the quotients from 150 kD and 52 kD it can be possible to distinguish between primary and secondary infections.

The cytomegalovirus is a member of the Herpesviridae family, together with the Herpes simplex virus, types 1 and 2, the varicella-zoster virus, the Epstein Barr virus and the human herpes virus, types 6 and 7. The most important common pathogenic factor of the Herpesviridae is their ability to persist latently in the infected organism and, after reactivation, to cause recurrent infections.

1 % of all neonates are infected prenatally with CMV. The cerebral and visceral symptoms of classic neonate cytomegalovirus need only be expected if the primary infection of the mother occurred during pregnancy. The cases caused by recurrent infections usually run a clinically inapparent course, but even in these cases the infection can cause hearing damage and intelligence deficiency.

25 % of all neonates are infected perinatally. These infections usually follow a course free of symptoms and without later complications.

Only infections transmitted iatrogenically by blood transfusion to premature infants or ill neonates lacking in maternal immune protection can be life-threatening.

An infection in later childhood or at an adult age usually runs a clinically inapparent course or appears as a feverish infection with lymphadenitis. In some circumstances, the clinical and haematological picture of infectious mononucleosis is produced.

In patients with immunodeficiency (e.g. patients with AIDS), and iatrogenic immunosuppression, CMV is clinically the most important opportunistic pathogen. Interstitial pneumonia, retinitis and ulcerative enterocolitis can often be observed, and worsen the prognosis of the original infection considerably. In patients who have undergone a transplant, primary or recurrent infections can cause the transplant to be rejected.

The anti-CMV IgM cannot be detected in up to half of all cases in neonates and babies. The detection of anti-CMV IgM in older children and adults is not proof of a primary infection, but merely points to a certain degree of activity of the infection.

CytomegaloVirus IgG + IgM + IgA Immunoblot makes possible the detection of the following specific bands:

Cut off - Standard setting: IgM - 10 %, IgG - 20 %

Interpretation of the results