Lymphocyte Doubling Time (CLL)

Lymphocyte doubling time: from two absolute lymphocyte counts and the interval, the projected time to double the lymphocyte count; ≤ 12 months marks a worse CLL prognosis.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Earlier absolute lymphocyte count
20 ×10⁹/L
Later absolute lymphocyte count
40 ×10⁹/L
Interval between counts
6 months

Result: Lymphocyte doubling time 6 months — worse prognosis (<= 12 months).

The tool opens with these values already filled in. Replace them with your own.

What the result means

<= 12 months
Worse CLL prognosis.
> 12 months
More favorable. LDT = interval x ln(2) / ln(ALC2/ALC1). A prognostic estimate, not a treatment order.

What you enter

  • Earlier absolute lymphocyte count
  • Later absolute lymphocyte count
  • Interval between counts
How this is calculated

Molica S, Alberti A. Prognostic value of the lymphocyte doubling time in chronic lymphocytic leukemia. Cancer. 1987;60(11):2712-2716. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.