Anti-Granulocyte-macrophage colony-stimulating factor (GMCSF) autoantibodies
Test Code
GMCSE
Description
The association of anti-cytokine antibodies with immune dysregulation, immune deficiency or autoimmunity is increasingly being recognized. Anti-GMCSF autoantibodies have long been established to be associated with pulmonary alveolar proteinosis (PAP).
Low titer anti-cytokine autoantibodies may be detected in normal individuals and may serve a regulatory purpose. However, anti-cytokine autoantibodies associated with pathological findings tend to be of high titer and demonstrate significant neutralizing activity in vitro. Recognition of these autoantibodies is of benefit since it may direct the use of adjunctive immunotherapy to modulate the autoantibody titer while continuing with conventional therapies.
The GM-CSF ELISA assay detects auto-antibodies to granulocyte-macrophage colony stimulating factor (GM-CSF). If positive, will reflex with a validated flow cytometry assay that measures the ability of the autoantibody to neutralize GM-CSF mediated responses.
Collect
Collect in a plain red top tube or SST
Patient Prep
Preferred volume: 1 mL serum
Pediatric Collection
Minimum volume: 0.5 mL serum
Unacceptable Conditions
Clotted or hemolyzed samples, plasma
Storage Transport Temp
Send specimen to lab as soon as possible after collection. For shipped samples, send serum Priority Overnight via FedEx and in a well insulated container frozen on dry ice.
Stability
2-8°C for 48 hours, >1 month frozen at -20°C or below
Performed
Monday - Friday
Methodology
ELISA followed by confirmation by flow cytometry.
Turnaround Time
14 days
Department
Immunology Lab - Functional Assay
Synonyms
PAP, pulmonary alveolar proteinosis, intracellular infection, GMCSFA
Study Offerings
CAP/CLIA
Related Tests
IFNGE
Reference Interval
Negative
Interpretation
Granulocyte-macrophage colony-stimulating factor (GM-CSF) promotes the proliferation and differentiation of hematopoetic cells including macrophages, neutrophils and dendritic cells. Neutralization of GM-CSF activity can therefore impair the development and/or function of these cell types.
Neutralizing anti-GM-CSF autoantibodies are associated with pulmonary alveolar proteinosis (PAP), a rare lung disease that is characterized by the inability of macrophages to clear surfactant from the alveolar lung spaces. Additionally, anti-GM-CSF autoantibodies have been noted in patients with opportunistic infections with intracellular organisms such as M. avium complex, Cryptococcus, Nocardia and Aspergillus species. It is possible that neutralization of GM-CSF in vivo leads to compromised macrophage function which is a key component of the immune response to intracellular organisms.
Anti-GM-CSF autoantibodies are detected by an initial screening ELISA. If the result is positive, the test reflexes to a flow cytometry assay to determine the ability of the autoantibody to neutralize GM-CSF. Low titer, non-neutralizing autoantibodies may be detected in healthy individuals. Clinically significant anti-GM-CSF autoantibodies are reported when both the ELISA and the ability to neutralize GM-CSF are positive.
References:
Kitamura, T., et al. Idiopathic pulmonary alveolar proteinosis as an autoimmune disease with neutralizing antibody against granulocyte/macrophage colony-stimulating factor. The Journal of experimental medicine. 1999; 190:875-880.
Bonfield, T. L., et al. Anti-GM-CSF titer predicts response to GM-CSF therapy in pulmonary alveolar proteinosis. Clinical Immunology. 2002; 105:342-350.
Rosen, L. B., et al. Anti-GM-CSF autoantibodies in patients with cryptococcal meningitis. Journal of Immunology. 2013; 190:3959-3966.
CPT Code
83516 - ELISA
86353, 88184, 88185 - Flow cytometry reflex
New York Approved
No: Run with Waiver
FDA
LDT