Rickettsia (RMSF) Antibodies (IgG, IgM) with Reflex to Titers [6419]

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Test Code

Alias/See Also

CPT Codes
86757 (x2)

If RMSF IgG is Detected, then RMSF IgG Titer will be performed at an additional charge (CPT code(s): 86757).
If RMSF IgM is Detected, then RMSF IgM Titer will be performed at an additional charge (CPT code(s): 86757).

Preferred Specimen
1 mL serum

Minimum Volume
0.2 mL

Transport Container
Plastic screw-cap vial

Transport Temperature
Room temperature

Specimen Stability
Room temperature: 7 days
Refrigerated: 14 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic

Immunofluorescence Assay (IFA)

Setup Schedule
Set up: Tues-Sat; Report available: 1-4 days

Even after infection has been treated, positive results may persist. False-positive reactions may occur during pregnancy.

Reference Range
  Screen Titer
RMSF (IgG) Not detected <1:64
RMSF (IgM) Not detected <1:64

Clinical Significance
Antigen specific IgG and IgM titers allow rapid diagnosis of infection by any of the spotted fever group of rickettsial agents. This group of agents include R. rickettsii (Rocky Mountain Spotted Fever) and R. akari (rickettsial pox), both seen in the continental United States.

Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153

Last Updated: December 6, 2021

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.