Example Data Table
This example is fictional and for demonstrating features only.
| Scenario | IL-6 (pg/mL) | TNF-α (pg/mL) | IL-10 (pg/mL) | Dilution | Notes |
|---|---|---|---|---|---|
| Baseline-like | 3.2 | 4.1 | 2.9 | 1 | Often aligns with low-pattern flags. |
| Moderate elevation | 18.0 | 10.5 | 7.8 | 2 | Shows ratio increases after dilution adjustment. |
| Strong elevation | 95.0 | 32.0 | 28.0 | 1 | Higher CAI and stronger flagging behavior. |
Formula Used
- Unit standardization: pg/mL = value × unit_factor, where unit_factor is 1 for pg/mL and ng/L, and 1000 for ng/mL.
- Dilution adjustment: adjusted_pg/mL = standardized_pg/mL × dilution_factor.
- Relative elevation: ratio = adjusted / upper_limit (only when an upper limit is provided).
- Nonlinear score: score = 100 × log10(1 + ratio), capped to 300 for readability.
- Cytokine Activity Index (CAI): weighted mean of individual scores using row weights.
How to Use This Calculator
- Select your input unit and enter the dilution factor used in your assay.
- Add cytokines, enter measured values, and optionally provide upper limits.
- Adjust weights if some markers should influence CAI more.
- Click Calculate. The result appears above the form.
- Use Download CSV or Download PDF to save summaries.
Why quantify cytokines
Cytokines are short-range signaling proteins that coordinate innate and adaptive immunity. Concentrations often shift quickly after infection, tissue injury, vaccination, or therapeutic modulation. Many laboratories report results in pg/mL and observe broad dynamic ranges, commonly from about 1 to 10,000 pg/mL depending on platform. This calculator standardizes units, adjusts dilution, and summarizes patterns across a small panel.
Unit conversion and dilution control
For comparability, every entry is converted to pg/mL using a unit factor: pg/mL and ng/L are equivalent, while ng/mL multiplies by 1000. Dilution factor corrects pre-analytical handling or assay setup, so adjusted value equals raw value times unit factor times dilution. Record the dilution used for standards and samples, and keep it consistent across markers. For plasma, note anticoagulants can shift apparent levels; EDTA, citrate, and heparin behave differently, so match the reference interval to the collection tube type used.
Reference limits and ratio scoring
Interpretation depends on a reference interval validated for the assay, matrix, and cohort. When you provide an upper limit, the tool computes ratio equals adjusted divided by upper. A nonlinear score, 100 times log10 of 1 plus ratio, emphasizes meaningful elevations while reducing the impact of small fluctuations. Leaving an upper limit blank skips ratio scoring for that row.
Cytokine Activity Index overview
The Cytokine Activity Index is a weighted mean of per-marker scores. Weighting lets you prioritize sentinel markers, for example IL-6 or TNF-alpha, without discarding other information. The pattern flag uses CAI and the maximum ratio to highlight low, moderate, high, or critical elevation patterns. It is a screening summary, not a diagnosis, and should be interpreted alongside symptoms, timing, and medication history.
Reporting and quality checks
Before sharing a report, review replicate variability, calibration curve fit, and the stated limits of detection and quantification. Many teams target intra-assay CV under 10% and inter-assay CV under 20% as practical goals, but acceptability depends on purpose. Consider hemolysis, lipemia, matrix mismatch, and freeze-thaw cycles that can bias some analytes. Use the CSV export for downstream statistics and the PDF export for a snapshot of the calculated adjustments. If results look inconsistent, re-check units, dilution, and reference limits first.
FAQs
What does the Cytokine Activity Index mean?
The CAI is a weighted average of per-marker elevation scores. It condenses a small cytokine panel into one comparable number, useful for trend tracking between runs when the same units, dilution, and reference limits are used.
Why do I need an upper limit?
Upper limits enable ratio and score calculations. Without a limit, the tool still standardizes and adjusts the value, but it cannot quantify relative elevation against a reference interval for that marker.
How are units converted to pg/mL?
pg/mL and ng/L are treated as equivalent. ng/mL is multiplied by 1000 to convert to pg/mL. The calculator then applies your dilution factor to compute the adjusted concentration.
Should dilution factor be 1 when undiluted?
Yes. Use 1 when the reported value already reflects the final sample concentration. If the assay used a 1:2 dilution, enter 2 so the adjusted value reflects the original concentration before dilution.
Can I include a custom cytokine?
Yes. Choose the Custom option and type the marker name. Provide its value and an appropriate upper limit for your assay. The calculator will treat it like any other marker in scoring and CAI.
Why do my PDF and CSV look different?
The CSV contains raw numbers for analysis and reformatting, while the PDF captures the on-screen summary card. If you change entries and recalculate, download again to keep both exports synchronized.