Human IL-15
131
SUMMARY AND EXPLANATION OF THE TEST
Interleukin 15 (IL-15) is a glycosylated 14-15 kDa cytokine with structural similarity to IL-2. Like IL-2, IL-15 binds to and signals through the
IL-2/IL-15 beta chain (CD122) and the common gamma chain (gamma-C, CD132). IL-15 is constitutively expressed by a large number of
cell types and tissues, including monocytes, macrophages, dendritic cells, keratinocytes, fibroblasts, and nerve cells. IL-15 up-regulation
plays a central role in the development of several autoimmune or chronic inflammatory disorders. This cytokine induces cell proliferation
of natural killer cells; cells of the innate immune system whose principal role is to kill virally infected cells. IL-15 has been shown to
enhance the anti-tumor immunity of CD8+ T cells in pre-clinical models.
Healthy donors
Median [IL-15]
3.78 pg/mL
EDTA plasma
Serum
IL-15, pg/mL
%CVdose
AEB
Median [IL-15]
3.23 pg/mL
IL-15, pg/mL
IL-15, pg/mL
Figure 1: SimoaTM IL-15 immunoassay calibration
curve. Four-parameter curve fit parameters are
depicted.
Figure 2: Simoa IL-15 CV profile. Diluted
serum samples were assayed in reps of 3 over
multiple days (28 determinations). Dose CVs
are depicted.
Figure 3: [IL-15] in EDTA plasma (n = 20) and
matched serum (n = 20). Error bars depict mean
and SEM.
Table 1: General characteristics of Simoa Human IL-15 immunoassay
Calibration range
0-10 pg/mL
Dynamic range1
0-40 pg/mL
Lower limit of detection (2.5 SD from zero, n = 3 reps x 10 runs over 5 days, mean LoD2)
0.0030 pg/mL
Lower limit of quantification (≤20% CVdose, see Figure 2)
0.0062 pg/mL
Spike-recovery (IL-15 spiked into 4 serum samples at 2 levels, mean3)
104.2%
Linearity (high IL-15 serum sample admixed with low IL-15 sample, mean of 10 levels)
104.9%
25 µL
Sample volume
1Samples
auto-diluted 4X.
The Simoa Human
IL-15 immunoassay
reliably quantifies
IL-15 in serum and
plasma in healthy
subjects, with
median IL-15 values
well above the
sensitivity limits.
2SD
of LoD estimates 0.00217pg/mL.
3Range
95.8-116.2%.
Table 2: Precision characteristics of Simoa Human IL-15 immunoassay. Precision was determined with
guidance from CLSI Protocol EP5-A. Five samples consisting of three serum-based panels and two IL-15 controls were
assayed in replicates of three at two separate times per day for five days using a single lot of reagents and calibrators.
Analysis of variance (fully nested ANOVA) results are summarized in the following table.
Sample
Control 1
Control 2
Panel 1
Panel 2
Panel 3
Assay designed by Evan
Mean IL-15
Within Run
Between Run
Between Day
(pg/mL)
%CV (n=30)
%CV (n=10)
%CV (n=5)
0.346
5.79
3.16
4.6
4.9
11.9
4.0
7.1
3.8
0.0
2.0
4.5
4.23
26.2
11.7
4.9
6.0
6.5
0.0
1.7
Simoa
HD-1 Analyzer
For Research Use Only. Not for use in diagnostic procedures.
USER-131-02 09JAN2015