Platelet-to-Lymphocyte Ratio (PLR)

Basis: Reactive thrombocytosis may occur with tumors. Lymphocytopenia is associated with immune defects.

Parameters:

(1) platelet count

(2) absolute lymphocyte count

platelet to lymphocyte ratio =

= (platelet count) / (absolute lymphocyte count)

Interpretation:

• An elevated PLR is associated with worse prognosis for several malignancies, with cutoffs ranging from 150 to 300.

• A PLR >= 140 is associated with increased inflammation in end-stage renal disease.

• A PLR >= 150 is associated with IVIG resistance in Kawasaki disease.

Performance:

• Chemotherapy and infection can affect both platelet and lymphocyte counts.