Specimen:

Serum

Collection Medium:

Minimum:

Adult Preferred Mimimum:  2.0 mL serum
Absolute Minimum:  0.5 mL serum

Rejection Criteria:

Contaminated, heat-inactivated or hemolyzed specimens

Analytic Time:

24 hours (upon receipt in laboratory)

Reference Range:

Rubella Antibody, IgG
   Less than 5 IU/mL: Negative
      No significant level of detectable rubella IgG antibody.
   5-9 IU/mL: Equivocal
      Repeat testing in 10-14 days may be helpful.
   Greater than 10 IU/mL: Positive
      IgG antibody to rubella detected, which may indicate a current
      or previous exposure/immunization to rubella.

Rubella Antibody, IgM
   0.89 IV of less: Negative
      No significant level of detectable rubella IgM antibody.
   0.90-1.09 IV: Equivocal
      Repeat testing in 10-14 days may be helpful.
   1.10 IV or greater: Positive
      IgM antibody to rubella detected, which may indicate a current
      or recent infection or immunization.

Comments:

Acute and convalescent samples must be labeled as such; parallel 
testing is preferred and convalescent samples must be received within 
30 days from receipt of the acute samples. Please mark sample plainly 
as "acute" or "convalescent".

Test
Limitations:

In children and adults, rubella infection usually results in a mild 
exanthematous disease. However, infection during pregnancy, 
particularly in the first trimester, can result in fetal death or the 
"rubella syndrome," a spectrum of congenital defects that includes 
cataracts, deafness, glaucoma, congenital heart disease, and mental 
retardation. About ten to 20 percent of newborns infected in utero fail 
to survive past the first year of life. Since complications of 
congenital rubella infection are so severe, diagnosis of infection 
during the first trimester of pregnancy may influence the decision to 
terminate or continue the pregnancy. Thus, it is important to determine 
the rubella immune status in women of child-bearing age, in pregnant 
women, and in individuals who may have close contact with them, such as 
hospital personnel and preschool children.

In a patient suffering from a primary rubella infection, the appearance 
of both IgG and IgM antibodies is associated with the appearance of 
clinical signs and symptoms when present. IgM antibodies become 
detectable in a few days after the onset of signs and symptoms and 
reach peak levels in seven to ten days. These antibodies persist, but 
rapidly diminish in concentration over the next four to five weeks 
until the antibody is no longer clinically detectable. The presence of 
IgM antibody in a single specimen suggests that the patient has 
recently experienced a rubella infection. In most cases, the infection 
probably occurred within the preceding one to three months. Rubella IgM 
antibody in a newborn's serum suggests congenital infection since IgM 
from the mother is not transferred to the infant across the placenta. 
The infected infant, in contrast to a woman with prenatal rubella, may 
continue to produce rubella-specific IgM for several months.

Methodology:

Chemiluminescent Immunoassay

CPT Code:

86317 Rubella IgG, 86762 Rubella IgM