Elecsys® CMV IgM

Immunoassay for the qualitative determination of IgM-antibodies against CMV

Elecsys® CMV IgM

Immunoassay for the qualitative determination of IgM-antibodies against CMV

Cytomegalovirus (CMV) is a herpes virus ubiquitous in humans, and it is the leading infectious cause of congenital malformations1. The global prevalence ranges from 40 to 60 % in Western industrialized countries and from 80 to 100 % in low-resource rural areas and developing countries2.

CMV is transmitted by direct contact of mucous membranes with infectious body fluids, but transmission can also occur following transfusion of blood products and transplantation of organs from seropositive donors3. In healthy individuals acute infection is mostly subclinical or asymptomatic and turns latent.4 Reactivation in immunocompromised people is frequently associated with severe clinical consequences.4 Vertical transmission occurs from an infected mother to the fetus during pregnancy.4 Due to latency following primary infection and periodic reactivation of CMV replication causing recurrent infections, in utero transmission of CMV may follow either primary or recurrent infections.4 Consequences include severe fetal damage, growth and mental retardations, jaundice and CNS abnormalities. If unsuspicious at birth, hearing defects or cognitive deficits may develop later in life.4

There is currently no generally accepted therapy available.4 The diagnosis of CMV infection usually starts with the detection of anti-CMV IgG and IgM antibodies, and IgG avidity test to determine the age of the infection. Samples being reactive for CMV IgM antibodies indicate an acute, recent or reactivated infection. A positive IgM result in combination with a low avidity index for IgG detected before the 16th – 18th week of pregnancy is an indication of a primary CMV infection within the preceding 3 to 4 months, whereas high avidity during the first 12 – 16 weeks excludes primary infection within the preceding 3 months4.

Elecsys® CMV IgM

Elecsys® CMV IgM

  • Systems

    cobas e 411 analyzer, cobas e 601 / cobas e 602 modules, cobas e 801 module

  • Testing Time

    18 minutes in parallel 

  • Test principle

    μ-capture assay    

  • Calibration

    2-point

  • Interpretation

    COI <0.7 = non-reactive
    ≥0.7 – <1.0 COI = indeterminate
    COI ≥1.0 = reactive    

  • Traceability

    This method has been standardized against a Roche standard (arbitrary units) 

  • Sample material

    Serum collected using standard sampling tubes or tubes containing separating   gel. Li-heparin, Na‑heparin, K2‑EDTA, K3‑EDTA, ACD, CPD, CP2D, CPDA and   Na‑citrate plasma.    

  • Sample volume

    10 μL cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
    6 μL cobas e 801 module

  • Onboard stability

    14 days for cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
    16 weeks for cobas e 801 module

  • Intermediate precision

    cobas e 411 analyzer: CV 3.2 – 5.3 %    
    cobas e 601 / 602 modules: CV 3.8 – 6.1 %    
    cobas e 801 module: CV 1.4 – 2.2 %

  • Sensitivity in primary infections

    93.0 % (n = 114)
    93.1 % (n = 29)
    92.3 % (n = 52)
    91.2 % (n = 34)
    96.5 % (n = 57)    

  • Specificity in routine samples

    98.8 % (n = 501) lower 95 % C.I.: 97.4 %
    97.1 % (n = 591) lower 95 % C.I.: 95.4 %
    97.0 % (n = 507) lower 95 % C.I.: 95.2 %    

References

 

  1. Van Zuylen, W.J. et al. (2014). Obstet Med 7, 140-146.
  2. Buxmann, H. et al. (2017). Dtsch Arztebl Int 114, 45-52.
  3. Ljungman, P. (2004). British Journal of Haematology 125, 107-116.
  4. Revello, M.G. et al. (2002). Clin Microbiol Rev 15, 680-715.