Gold (SST - Clot activator & gel)
2 ml blood
1 ml serum
If multiple viral serologies are being requested from the same specimen, the general rule is to collect a total of 2-4 ml of blood for every 2-3 tests ordered. A single serum specimen is required to determine the immune status of an individual or to test for viral-specific IgM antibodies. Paired sera specimens, collected two to three weeks apart, are required for the diagnosis of a current or recent viral infection when examining specimens for IgG antibody. Obtain the acute phase serum as soon as possible after the onset of illness. The most useful results are obtained by submitting acute and convalescent phase sera together to be tested simultaneously. Evaluation of serum for antibodies to TORCH (Toxoplasma, Rubella, CMV, HSV, etc) agents can be used to detect congenital and perinatal infections in newborns. Two serum specimens should be submitted for testing; one from the mother and the other from her infant. Serological testing is not usually available for body fluids other than serum. However, in patients with viral neurologic disease, cerebrospinal fluid (CSF) may be tested for viral antibody if paired with a serum specimen from the same date.
<0.9 - No Mycoplasma pneumoniae IgG antibody detected
0.9-1.10 - Equivocal for Mycoplasma pneumoniae IgG antibody
>1.10 - Positive for mycoplasma pneumoniae IgG antibody
Negative or no Mycoplasma pneumoniae IgG antibody detected
Clinical Utility: Serological assays provide an indirect diagnostic approach by detecting specific antibody responses to Mycoplasma pneumoniae infections. Detection of M. pneumoniae-specific IgM in a single serum sample or demonstration of a seroconversion from a negative to a positive IgG antibody response between acute and convalescent sera collected 2-3 weeks apart can be diagnostic of current or recent Mycoplasma pneumoniae infection. Detection of M. pneumoniae-specific IgG in a single serum specimen indicates exposure at some time in the past. Negative antibody titers may exclude M. pneumoniae infection. Results of serological tests must be interpreted with caution, as measurements of antibody responses to M. pneumoniae infections can be complicated by numerous factors. Nucleic acid amplification methods (e.g., PCR) are also available for Mycoplasma pneumoniae and may yield results in a more sensitive and timely manner.