Rickettsia rickettsii (Rocky Mountain Spotted Fever) Antibody, IgM
0050372
 
Ordering Recommendation
Mnemonic
RMSF M
Methodology
Semi-Quantitative Indirect Fluorescent Antibody
Performed
Mon-Fri
Reported
1-5 days
New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
 
Collect
Serum separator tube.  
Specimen Preparation
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.1 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as acute or convalescent.  
Storage/Transport Temperature
Refrigerated.  
Unacceptable Conditions
Contaminated, hemolyzed, or severely lipemic specimens.  
Remarks
 
Stability
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)  
Reference Interval
Less than 1:64: Negative - No significant level of Rickettsia rickettsii Antibody, IgM detected.
1:64 or greater: Positive - Presence of Rickettsia rickettsii Antibody, IgM detected, which may indicate a current or recent infection; however, low levels of IgM antibodies may occasionally persist for more than 12 months post-infection.
Interpretive Data
The CDC does not use IgM results for routine diagnostic testing of Rocky Mountain Spotted Fever, as the response may not be specific for the agent (resulting in false positives) and the IgM response may be persistent from past infection.
Note
CPT Code(s)
86757
Components
Component Test Code*Component Chart Name
0050372Rocky Mt Spotted Fever IgM
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, contact interface support at interface.support@aruplab.com.
Cross References
  • Rickettsia
  • RMSF
  • Rocky Mountain Spotted Fever