International prognostic index for lymphomas includes the following prognostic factors, except -

The prognosis of patients with NHL is best assigned using the International Prognostic Index (IPI) . This is a powerful predictor of outcome in all subtypes of NHL. Patients are assigned on IPI score based on the presence or absence of five adverse prognostic factors:- Age > 60 years Elevated serum LDH Performance status 2 (ECOG) or ≤ 70 ( Karnofsky) > 1 site of extranodal (extra lymphatic ) involvement Ann Arbor Stage III or IV